Evolution of Printed Circuit Board(PCB)


This chapter is all the evolution of the Printed Circuit Board since they were invented, the changes they have undergone, through the years, their present state, and the future of these components.

A Printed Circuit Board (PCB) is a gadget that is meant to provide mechanical support and connect all the electronic components through the use of conductive pads and other features etched from copper sheets and overlaid into a material that does not conduct electricity.

Before the Printed Circuit Boards became the standard in the production of electronics, the industry majorly relied on point-to-point construction. This method led to unreliable designs and bulky products which required large sockets. The problem was eliminated when the PCB became part of the production of electronics.

The 1st Printed Circuit Boards are nearly not recognized as compared to the modern designs in the present age. The important function was for creation of an electrical path on an insulating substrate for movement and control of the electrical current. Since the invention of the first PCB, a lot of changes have been made to improve the concept. Both developments of the material and computerization have aided in the continued evolution of Printed Circuit Board into other circuits that are being used in modern days electronics.


Paul Eisler is the first intellectual who invented the Printed Circuit Board in the 20th century. He is, therefore, the father of the Printed Circuit Board.

He developed the PCB to operate a radio system.

Printed Circuit Boards and their year of manufacture.

  • The invention of Charles Ducas in 1925 called “Printed wire” involved the creation of an electrical path direct to an insulated surface on a flat timber board. Though the concept eliminated the use of complex wiring it did not work.

  • In 1936, the father of PCBs Paul Eisler developed the first PCB to be used in the radio system. The same technology was taken up by the military of the United States and was used in the proximity fuses that were used during the period of World War II.

PCB diagram of 1936.


A Proximity fuse is used to donate an explosive device automatically when the distance between the target becomes smaller than the expected value.

A fuse contains only the mechanical or electronic elements used to signal or actuate the detonator. Some fuses have a small amount of primary explosive to initiate the detonator and others may have fused with large explosive charges that include an explosive booster. The diagram below shows a proximity fuse.

A radio proximity fuse for anti-aircraft

  • In 1943, Eisler continues to improve in his invention of the PCB to a higher advanced design that involved etching of the circuits on copper foil on a non-conductive material i.e., glass, paper.

The above diagram shows the 1943 Printed Circuit Board

  • In 1944, Britain and the US worked together and developed proximity fuses to be used during mining, making of bombs, and artillery shells throughout of WWII.

The above diagram shows a Printed Circuit Board of 1944

  • In the year 1948, the army of the US released printed circuit board tech to the citizens, and the Printed Circuit Board (Printed Wiring Boards), PWBs started to evolve.

The above diagram shows 1948 Printed Circuit Board

  • In the 1950s, transistors were discovered and introduced into the market which led to a reduction in the overall size of manufactured electronics. It also made it easier to use the Printed Circuit Boards and slowly improved the eelectronic’sreliability.

A diagram showing different types of resistors

1950 Printed Circuit Board

  • Between the 1950s and 1960s, double-sided Printed Circuit Boards evolved. One side consists of electrical components and the other side identification printing. The PCB designs are incorporated with zinc plates together with corrosion-resistant substances and coating are applied in order to avoid degradation.

A double-sided Printed Circuit Board

  • In the 1960s, Integrated Circuit is introduced to the electronic designs industry. An (IC) also known as silicon chip-enabled millions of components to be put on that single chip producing more power and reliability than before in the electronics that had these devices. In order to accommodate a new number of Integrated Circuits, the conductors in the Printed Circuit Board had to grow higher resulting in many layers in a single PCB. The ICs are small which leads to a reduction in the size of the PCB making the connections and soldering to become difficult.

The diagram above shows the 1960 Integrated Chip/silicon chip

  • During 1970, PCBs are incorrectly being connected to the dangerous polychlorinated biphenyl, PCB chemical. This resulted in confusion in the public together with the health department. The Printed Circuit board name was then changed to Printed Wiring Board (PWB) until in the 1990s when the PCBs were phased out.


The diagram below shows a 1970 PCB

  • Between the 1970s and 1980s, a solder stop mask of polymer material is developed to initiate easier soldering application to the copper circuit without dividing between adjacent circuits by a greater distance increasing the circuit density. An imageable polymer material coat is developed and can be applied to circuits and modified further improvement of the circuit density.

The solder stop mask is applied to the copper traces of the Printed Circuit Board to protect it against oxidation.

Printed Circuit Board solder stop mask.

  • In the 1980s, new technology was developed and was named SMT. All the previous Printed Circuit Boards had wire leads that had to be soldered into the holes of the PCB. The holes consumed a larger space which when used well could lead to the mounting of another circuit. When the surface mount technology components were introduced and were soldered directly to the small pads of the PCB without the holes. They became the manufacturing standard and were applied to replace hole components also improving power, and reliability as it leads to reducing electronic production costs.

Surface Mount Technology



  • Through-hole components are expensive to manufacture compared to surface mount technology.
  • Surface mount technology does not have leads while through-hole components have holes for mounting.
  • Surface mount technology requires advanced design compared to through-hole technology.
  • Surface mount technology has a lot of mounting pins as compared to through-hole components.
  • Surface mount technology enables automation at lower costs as compared to through-hole technology.
  • Surface mount technology has high production at low costs as compared to through-hole technology.



  • SMT designs are light due to the smaller PCB design.
  • Production process setup is faster.
  • SMT gives room for high circuit speeds.
  • Components can be placed on two sides of the circuit board.




  • You require to hire a skilled person at an expensive cost.
  • Tools for the components are expensive to acquire.
  • Most surface mount technology components are difficult to install.
  • The reliability of solder joints becomes a concern since less solder is applied to the joints.
  • It is not easy to identify components.



In Through-hole technology, electronic components have leads that are inserted into drilled holes in a Printed Circuit Board and soldered to pads on the other side.


  • It is more reliable for products that require strong connections between the layers since it can withstand a lot of stress.
  • Its bonds are more expensive enabling it to be reserved for heavy components.
  • It can be used with breadboard sockets.


  • Consumes a lot of time during production due to the drilling of multiple holes.
  • Costs of production are high.
  • The holes consume a lot of space on the board.
  • Tracing signals is not easy.


  • In the 1990s, Printed Circuit Boards continues to become smaller as CAD becomes more famous. The use of computer designs automated many steps in the Printed Circuit Board and leads to complex and advanced designs with smaller and lighter, perfect and miniature components. The manufacturers work to improve their device’s performance, reduction of electrical consumption and cost.

  • In the 2000s, the Printed Circuit Boards manufactured have become tiny in size, have more layers, and are complex.

The Flexible printed circuit boards became common and provided an cost friendly option and helped in saving a lot of space which was ideal for designing packages.

An improved Printed Circuit Board of 2000

  • In 2006, a process called Every Layer Interconnect (ELIC) was developed. The process uses stacked micro vias that are filled wih coper to make the connections through the layers of the PCB. This enables the developers to make proper connections between two or more layers in the board.

Since the invention of Printed Circuit Boards and their introduction of them into the market for usage, various types of PCBs have evolved as listed and discussed below.

  1. Single-sided/ one side printed circuit board.
  2. Double-sided/ two sides printed circuit board.
  3. Multilayer printed circuit board.
  4. Rigid printed circuit board.
  5. Flexible printed circuit board.
  6. Rigid-flex printed circuit board.
  7. High frequency printed circuit board.
  8. Aluminum-backed printed circuit board.

Single-sided printed circuit board

In single-sided printed circuit board, it contains only one layer of the base material. The layer which is covered with a thin layer of copper metal is a good conductor of electricity.

The PCB has a protective solder mask that is applied on top of the copper layer.

Process of making a single-sided printed circuit board

  • Using any CAD designing software to make a layout of the PCB.
  • Print your layout on the paper.
  • Take the copper plate fiberglass PCB substrate.
  • Iron the layout of the PCB on the copper side of the board.
  • Place the board in a solution of copper chloride for some time for copper to etch out.
  • Use a scraper to remove the laser ink from the PCB tracks
  • Apply a solder mask.
  • Do the drilling of holes
  • Do the soldering of all the electronic components.

Benefits of a single sided-PCB in the modern market.

  • The cost of production is low since fewer materials are needed.
  • The probability of failing is low.
  • It is easy to understand due to a smaller number of components.
  • Most suitable simple designs.

Most single-sided PCBs are used in;

  • Light-emitting diode.
  • The relays.
  • Calculators
  • Sensors
  • Power supply.
  • Timers
  • Radio
  • Printers
  • Camera

Double-sided printed circuit board.

A double-sided printed circuit board has two-sided traces on both the top and bottom layers. On both sides of the board, conductive copper can be mounted to allow traces of copper to cross over each other.

Advantages of double-sided PCB

  • they permit density in components thus making the laying of tracks a neater process.
  • It provides increased cooling.


The double-sided circuit board is applied in wide applications to satisfy the necessities of the project. The list below is where they’re applied.

  • Converters
  • Relay controls.
  • Power converters
  • LED
  • Controls within the industry
  • Power supplies.
  • Ultra-power saves systems.
  • Personal control hard drives.
  • Phone systems.
  • Power amplifiers.

Multilayer electric circuit board

A multilayer electric circuit board is formed with three conductive layers of copper foil. Several layers of the double-sided PCBs are laminated and sticked together with layers of insulations between them..

The whole building is arranged during this the two layers are placed on each sides of the pc circuit boards to form a connection to the sarrounding. The electrical connections are achieved by plated through holes (vias)

The multilayer circuit board came into existence due to evolving changes within the industry.

Electronics became more complicated over time and need more complex circuit boards.

The computer circuit boards are affected by noise, and crosstalk which ends within the requirement of following a particular design pattern. the design considerations make it hard/difficult to urge a satisfactory performance from one or double-sided circuit board which ends up within the existence of a multilayer electrical circuit board.

Multilayer electrical circuit boards became more popular within the electronics market. they’re made of different sizes and thicknesses so that it can accommodate or fit the needs of their use. Most PCBs have an honest number of layers since an odd number of layers can cause warping within the circuit which is cost-effective to produce.

Benefits of the multilayered circuit board

  • Are small in size but more powerful.
  • Are light in weight since the PCB is small in size.
  • Have the main quality compared to single and double-sided layer electrical circuit boards.
  • Have increased durability. they’re going to bind the heat and pressure used to bind them together.
  • Have flexible construction techniques.
  • Are more powerful.


  • they’re expensive to shop for.
  • they’re difficult to style.
  • Consume plenty of it slow during the manufacturing process hence tiresome.
  • Their availability is proscribed within the manufacturing industry.

Multilayer circuit board is extremely applied in complex systems named below.

Electronics i.e., smartphones. Each electronic contains a PCB.

In telecommunication systems for signal transmission and satellite applications.

Industrial control systems run the machinery due to its durability and functionality.

for treatment and diagnosis.

In automotive, cars have more electronic components used for various applications within the system.

RIGID electrical circuit BOARD

because the name suggests a rigid electric circuit board cannot bend from its original shape. it isn’t flexible and thus cannot be modified or folded into the opposite desired shape.

The following are the benefits of an electric circuit board.

  • Are cheaper
  • it’s more durable compared to flexible circuit boards.
  • Can exist for an extended period.
  • Has top of the range
  • Is applied to many electronic devices.
  • Has more demand and supply.

Uses of the rigid circuit board

Many companies on the planet use these types of boards in several electronic gadgets because they supply increased circuit density and reduce the load of the board.

  • ICT department
  • Telecommunication devices.
  • Servers
  • Signal transmission
  • In satellites
  • within the medical industry
  • In military equipment.

FLEXIBLE electrical circuit BOARD.

It is a circuit that gives connection to the electrical components with the help of the conductive copper wires in order to convey mechanical support? it’s the muse of various electronic projects, with miniature, compact, and fewer unpredictable PCB designs.

Let’s start.

A flexible PCB encompasses the conductive layer made out of tracks of copper.

Flexible PCBs types:

There exist four types of this flexible PCBs

  1. Single-Layer PCB

This as you will be ready to see from the name will have only 1 layer of copper that’s placed on top of the dielectric layer

  1. Multiple Layers

Has three or even more conductive copper layers that are separated apart by the dielectric substances.

  1. PCB with Rigid-Flex

This is a mixture of both the flexible and thus the rigid layers to form a board that will have the facility to combine many components with an excessive amount of flexibility.

  1. Flexible PCB from HDI

HDI is the abbreviation for high-density interconnect


  • Antilock brakes
  • Satellites
  • Medical devices
  • Cameras
  • Battery packs
  • Ultrasound probes
  • Fuel pumps
  • Motion systems
  • Avionics
  • Manufacturing devices
  • Airbag apparatus
  • Medical devices
  • Universal Product Code equipment
  • Semiconductor test

RIGID-FLEX computer circuit BOARD

The rigid-flex computer circuit board comprises rigid and versatile board technologies. The circuit card is created from several multiple flexible inner circuit layers. This has more benefits like stability, assembly, and signal transmission.

Rigid-Flex Circuits: Rigid-flex are made of many schematic layers that are connected by an epoxy pre-preg bonding film, almost like the multi-layer flex schematics. Component presence is higher in rigid-flex schematics.

The following are the advantages when employing a rigid-flex computer circuit board.

  • It is flexible hence enabling the manufacturer to form without many considerations.
  • Has a reduced packaging size hence light in weight.
  • It is often designed to suit smaller areas.
  • It will be utilized in highly demanding applications.
  • Has reduced circuitry failure thanks to the mixture of rigid and flex circuits.

HIGH-FREQUENCY computer circuit BOARD

They transmit electromagnetic waves with minimal losses. it’s mainly utilized where transmissions of signals between objects are required.

The board features a symptom flow at high rates. The circuit boards are mainly applied in HDI technology.

The following are applications of high-frequency computer circuit boards.

  • In communication systems
  • Production of ammunition and firearms employed in the military industry.
  • In the marine and aviation industries.

ALUMINUM-BAKED computer circuit BOARD

An aluminum computer circuit board is formed of a metal substrate that mainly contains a mix of aluminum.

The aluminum circuit boards are mainly employed in projects that need cooling and also the insulating dielectric is suitable for the availability of an appropriate exit for warmth.

They are mainly applied in;

  • LED circuit boards.
  • Used in power conversion systems.
  • Applied within the motor.

We have discussed how the computer circuit boards were invented and also the various stages they underwent until this day. The invention has made the manufacturing industry grow as things still change. this can be a changing world where technology is happening we should always be able to embrace it.


Introduction to PCB Panelization


Printed circuit board panelization is a technique where manufacturers of smaller boards manufacture them and connect them as a single array making it easier to move through an assembly line. The individual boards can easily be removed from the array for installation into a product.

An array which is also called a printed circuit board panel is a term used in printed circuit board manufacturing where a single PCB is combined multiple times to make a larger array of connected boards. The process is referred to as stepping out of the individual boards.

Many manufacturers have good ideas for coming up with different kinds of printed circuit boards. As they move to the warehouses to start producing them, it becomes difficult due to some misconceptions to come up with a standard printed circuit board. For this reason, it is important to have the following design considerations to meet the required standards in the industry.

Printed Circuit Board panel strength

An increased board count per panel increases the strength and reduces vibration. This then shows that for a manufacturer to produce a strong and long-lasting array board, he should consider using several arrays on the board.

The component layout

This includes the placement of all the components and connectors on the board. Those that hung off the edge are the ones that especially limit the penalization process. During the manufacturing process, the producer should be keen on the allocation of the components on the board to meet the standard.

Printed Circuit Board shape

Manufacturers produce different types of shapes of the Printed Circuit Board. The shape of the board can sometimes complicate parallelization. Some of the board shapes are complex. One can use Computer-Aided Design (CAD) software’s to fit unusually shaped boards into an array.

Tooling holes

All tooling holes should best be placed in the panel rather than in the circuit board when the boards are being placed in an array. The fabricators do not produce individual boards but produce panels, therefore, the holes should be placed in the panel.


Boards that are brought in the array are the primary reason for making an automated assembly less expensive and faster. Arrays can also be useful because they can allow the increase of tooling rails, and holes which help in assembling.

Tooling rails/ frames of the array. They make simplify how to hold the arrays during the assembling process as it provides stability.

The tooling holes should be drilled from the top to the rails such that the array can be pinned down to avoid unwanted motion during the process of assembly. They are drilled to a required specification.

Fiducials are made out of copper on the rails which help the automated pick-and-place equipment by giving an equal reference point.

There are majorly three types of array that the manufacturers use and the manufacturer has to determine which one to use.

They include;

  • Scored
  • Tab routed
  • The mixture of scored and tab routed


The proper printed circuit board array panelization and arrangement ensures there is a low rate of damaging the individual boards when handling and during assembly. Scored array offers a few important benefits for separating boards from the array.

Advantages of using a scored printed circuit board

  • It allows the designer to minimize the space between the individual boards.
  • Minimal cost of assembly
  • Less material per board is used.
  • Has better mechanical stability.


Tab routing is required when one has designed an irregular shape. Because the tab routed arrays are less sturdy than the scored arrays, the tooling rails should be added to all four sides of the array. This will give the array of printed circuit boards more support while handling the assembly process.

In tab-routed arrays, the printed circuit board is the one that is routed and held together using the small tabs.

In tab-routing panelization, the printed circuit board array that can conveniently use a V-groove method will instead use a tab routing method. With this type of method, the printed circuit boards are pre-cut from the array and held on the board with tabs.

Tab routing and scouring are used when board sides have given are straight and can be shaped while irregular sides should be tab-routed.

A diagram showing tab routing activity

In printed circuit board manufacturing, various components are chosen and used by the manufacturer to come up with the standard PCB required by the consumers. As a result, we have various methods of how to arrive at the required components to fit the need and meet panelization standards.

The following are various tips for choosing the components

  1. Component footprint Decisions

As a designer, you must select printed circuit board component footprints and land patterns that will provide strong roots for the printed circuit board components. It is always good when you use the numeric keys to make a plan. A designer who cannot follow and comply with the datasheet has a high tendency to get an incorrect component footprint that leads to more errors.

  1. Use of good grounding practices

The grounding planes are important features of the printed circuit board with all components that should possess the majority of the bypass capacitors. Capacitor size and frequencies should be keenly observed. You should ensure that you observe good grounding practices during the printed circuit design process.

  1. None-lead free components to be separated from lead-free components

It is very key to separate all defined lead-free parts from the undefined to make sure a lead-free arrangement when choosing a printed circuit board component. It is advisable to label all the ingredients as lead-free to avoid confusion. It is always important for the designer to make his or her customer aware of the modifications because there is a variation that exists between lead-free and non-lead-free.

  1. You should assign the virtual parts footprints

The virtual parts consist of power signals and ground. During the printed circuit board component schematic construction, all the virtual parts should be put into consideration and not ignore their importance in the process of designing printed circuit board components.

You should therefore get a better understanding of your printed circuit board assembly parts when you keep in touch with the bill of materials created.

  1. Make sure you have the complete bill of material (BOM) data

Bill of Materials data is another thing to give maximum attention and it should be complete. One can follow the bill of the material report to get the information after that to review and fill in the manufactures data on every single part before advancing to the printed circuit board design stage.

Suppliers can work faster and solve some problems earlier when they have a complete bill of material.

  1. Check the spare gates

To ensure that the whole printed circuit board works efficiently you have to check out for every additional obstacle. To ensure you promote the printed circuit board’s independent functions every spare gate in the drawing helps in understanding and running the board for other members. All component symbols made for printed circuit board layout and printed over the PCB board are helpful during the assembly and must be positioned correctly when connecting to unwired input.

  1. Every connection with one pad

The composition of the printed circuit board components must follow one rule which is one pad for one connection for proper alignment during the assembly process. If there are other components on the pad like the capacitors and resistors another pad must be recreated.

  1. Component package choice.

You should choose a component package that adds a touch of perfection to your design to speak for your work as a printed circuit board designer. Some choose components that work against them which leads to mistrust among their customers

The manufacturer also needs to choose what kind of board he will use to produce his printed circuit design. Before the development of the printed circuit boards, the board materials were being mostly covered by nests of entanglement that could easily fail. This could also result in a short circuit once the wires started to crack.

  1. Speak to your component delivery

This is another technique a printed circuit board with perfectly formed components. According to the bill of material, the printed circuit board components should be delivered in all parts to make sure the appropriate arrangement of all the kits.

It is important to have an agreement with the manufacturer on the best means to get the components to prevent problems encountered during the delivery process.

A printed circuit board consists of four layers that are heat laminated together into a single layer. The types of materials used in printed circuit boards from top to bottom are;

  • Silkscreen
  • Solder mask
  • Copper
  • Substrate


The silkscreen is the topmost layer of a printed circuit board that is used as a reference for placing components on the printed circuit board. It requires a special ink whose standards color is white, red, yellow, etc.

This layer applies ink traces to detect printed circuit board components, the test points, warning symbols, logos, and other marks. It can be found in the solder section. This kind of method is expensive.


Silkscreen designs vary from simple designs to complex ones that fail which if you do not apply is like having limited knowledge.

The guidelines below will guide you in making a workable silkscreen

  • The method your printed circuit board manufacturer uses to make silkscreens

Most manufacturers cannot make silkscreens using the three-screen printing methods. The printed circuit board method affects your primary design elements like the size location of markings and others.

  • Account for silkscreen items during printed circuit board layout

For someone to be able to read your screen well, marks such as polarity and reference indicators should be adjacent to their related components. As you make your design, you should be able to consider the additional spacing requirements to avoid covering the indicators.

  • Choose your fonts according to your manufacturer’s printing method

Some of the printed circuit board design packages will allow you to make any silkscreen font. However, your manufacturer may only be able to support a few fonts. You should therefore contact your chosen printed circuit board service provider and guide you in choosing the right font.

  • Do not use excess silkscreen markings

Do not be tempted to apply signs of every component and its information that is not useful to the assembly.

For you to make maximum use of printed circuit board identification and labeling even on small boards, you should observe the following.

  • Start with regulatory requirements.
  • Manufacturer markings and identification.
  • Prioritize aids like polarity.
  • Consider tasting aids like jumper indicators.

How to choose a printed circuit board silkscreen manufacturer

It is good and wise to seek services from reliable silkscreen manufacturers for you to produce high-quality products and have good services.

Almost all service providers have come up with a robust curve that suits the PCB printing process.

Ensure you maintain a good friendship with your manufacturer to perfect on Computer-Aided Design or the manual one before embarking on the actual production. This is where you will determine the font size, spacing, color, and other silkscreen design considerations.

After you are done, go through your design and check the errors and readability issues. Collaborate with your manufacturer to make good and valid decisions.

The Solder mask

The solder mask is also called solder resist. It is a thin polymer layer that is applied to the printed circuit board copper tracks to prevent oxygen reactions from taking place and also protect them against environmental damages.

when some

Purpose of solder mask

A solder mask is the printed circuit board’s primary protector from any form of corrosion and oxidation.

The solder mask also creates a cover between the soldered joints and other conductive parts during the assembly of the printed circuit board, therefore, protecting against the formation of the solder bridges.

Printed circuit board types of solder masks include

  • Liquid epoxy

It is a low-cost form. You simply have to use the woven mesh to support the ink-blocking pattern. The epoxy liquid acts as a thermoset polymer for hardening during curing. The solder mask dye is combined with this liquid epoxy.

  • Liquid photo imageable solder mask

This applies the photolithography technique that has a dry film. You can spray a liquid photo imageable solder mask over the board.

You are supposed to create the photography mask from the given Gerber files according to the required solder mask.

  • Dry film

Dry film is placed on sheets of solder mask with the aid of a vacuum laminated process. This process makes the unexposed solder mask stick to the printed circuit board and removes bubbles that may occur in the film. After the exposure, the unexposed mask should be removed using a solvent and thermally cured for the remaining ones.

  • Top and bottom side

On the two sides of the printed circuit boards, there are always two solder masks.

Copper in printed circuit boards

All printed circuit board manufacturers use copper because it is a good conductor of electricity. As the electric current moves along with the printed circuit board, copper keeps on heating which avoids damaging and stressing the entire printed circuit board. With other alloys, the printed circuit board could heat unevenly and the system may not function well.

Basics of copper base printed circuit board

It has multiple layers which include a copper base, an insulating layer, and the copper circuit layer. Copper-based PCB is divided into 2 categories.

  • Embedded copper coin printed circuit board
  • Buried copper coin printed circuit board

Advantages of copper printed circuit boards

  1. The copper track is used between various components which makes the entire unit small to fit in any tiny device.
  2. If any part of the printed circuit board is damaged and the labeling is transparent, the damaged part can easily be replaced.
  3. The copper PCB takes less time to assemble.
  4. Chances of the short circuit are eliminated due to its tight arrangement.
  5. Correctly laid copper PCB reduces noise which enhances good performance.
  6. Copper printed circuit boards are highly reliable and cost-effective

The disadvantage of copper printed circuit board

  • Copper printed circuit boards can carry less current due to their small size.
  • Its use is limited to small components only.
  • Its soldering needs maximum attention since it’s tiny in size.
  • It overheats and hence can damage the entire component.

Applications of copper printed circuit boards

Copper printed circuit board is applied in various fields of technology in different industries.

  • It is used in solar power converters to increase its efficiency.
  • Used in renewable energy.
  • Use in power rectification.
  • Used in communication devices.
  • Applied in overload relays.


Printed circuit board substrate is the substrate material used. The right choice in a printed circuit board design is the substrate used which is important for high-speed printed circuit board design. The substrate has a great influence on the finished printed circuit board design to withstand voltage, dielectric constant, and other electrical properties.

Types of substrates

Substrates can be grouped into five types each one of them having a unique set of characters and characteristics and specific applications.

  • Flame Resistant two

This is a lower grade of the substrate which is made of impregnated paper that is easy to machine over a fiberglass substrate material. It is also called phenolic.

  • Flame Resistant four

Fiberglass substrates are made up of fiberglass material.

  • RF

This substrate comprises low dielectric plates and is used in circuit boards for applications in high-power radio frequencies. This material is rigid and can also be drilled, cut, or machined

  • Flex

Not all circuit boards use rigid core materials. Some of them are designed to be slightly flexible or very flexible and are called flex circuits.


  1. Size of the panel

The maximum and minimum dimensions of the panel are determined by the machines used for each process of the printed circuit board manufacturing line. To enable proper handling of the panels the dimensions should be at least 50 mm in length.

  1. Form of the panel

Some of the PCBs have irregular contours to meet the standard of limited installation spaces hence lacking the two parallel edges. For proper handling, machines material should be added around the irregular-shaped printed circuit board.

  1. Handling margin

To ensure proper handling of the panels a narrow strip must be left free all around at the edge of the panel.

  1. Preparation of singulation

There are two different ways of preparing the panel for the final singulation. The preventive measures protect the panel and printed circuit board from damage and increase the cutting speed.

  1. Geometries of printed circuit boards

PCBs can have different and complex geometries due to individual requirements of the assembly. Mechanical separation like sawing is limited regarding their possible contour.

  1. Technical cleanliness

Many industries like medical technology need to ensure the technical cleanliness of surfaces and the cutting edges. Various panel separation processes are different in their possibilities in terms of the degree of purity they can achieve. Some of the methods produce large particles that cannot be removed easily.

  1. Space between printed circuit boards

For you to be able to cleanly cut out the printed circuit boards with the respective tool certain distances must be put into consideration during the design phase.


  • It saves on money and time
  • It improves work efficiency
  • It improves product quality
  • Prototype printed circuit design can add different design
  • It protects printed circuit board from vibration and shock

All manufacturers are therefore advised to choose the right components when coming up with their designs to fit the customers’ needs and work efficiently.


New Trends in PCB Manufacturing


The utilization of printed circuit boards (PCB), particularly in customer hardware, continues to grow rapidly. Generally, the growth is impelled by current electronic consumer requests for scaled-down and profoundly performing gadgets like cell phones and wearables. In certain areas like military and clinical, there is demand for high functionalities and advanced capabilities. Such requests can be achieved by applying and finding new materials, parts, and production methods.

Thusly the PCB business keeps on facing open doors and difficulties in the technological era. The financial advantage of limiting production costs becomes more vital for most manufacturers. However, as the business embraces state-of-the-art technology, creation cost ascends as manufacturers collaborate with tech specialists to use their facilities and stay on top of things.

While it is difficult to project the specific patterns that will drive the eventual pattern of the PCB business, an organization with clear visions can essentially impact the next generation of hardware by recognizing a challenge and finding answers to solve them. The most effective way of deciding what’s to come is by analyzing the current situation. Thusly, let us direct our concentration toward the top trends that will shape the fate of electronic industries.

What is a PCB?

A printed circuit board is a laminated board consisting of a conductive and insulating layer sandwiched together. PCBs have two corresponding capacities; attaching electronic parts in the assigned areas on the external layers through soldering.

Common types of PCBs

Printed circuit boards are grouped into different kinds given assembling process, design determination, and application prerequisites. Before picking a PCB design you want to use, you must consider the space required, handling capability, and mechanical and electrical dependability. Let’s take a look at these types of PCBs;

  • Single-sided PCBs.
  • Multilayer PCBs
  • Double-sided PCBs
  • Rigid PCBs
  • Rigid-Flex PCBs.
  • Flex PCBs

PCB Manufacturing Process

Before defining PCB manufacturing, it could be useful to define a couple of different terms and their interrelationships.

  • PCB Development: is defined as the most common way of taking a circuit board design to production. This normally incorporates three phases; plan, assembling, and testing.
  • PCB Manufacturing/ fabricating: This is the development or production of a PCB design. This is a 2-venture process that starts with board creation and ends with the assembly of PCBs.
  • PCB Testing: this is the 3rd phase of PCB production which is performed in the wake of assembling. Testing during improvement is done to access the board’s capacity to play out its expected functionality. During this stage, any mistakes or regions where the plan ought to be adjusted to further develop execution and one more is started to consolidate the plan changes.
  • PCB Assembly: PCBA is the subsequent phase in PCB production in which the board parts are mounted to the uncovered board through a soldering cycle/process.

Here is the PCB manufacturing process.

PCB manufacturing is the cycle or strategy that changes a circuit board plan into an actual construction in light of the determination given in the design package. This actual indication is accomplished through the below activities or procedures:

  1. PCB Design and output:

  • Circuit boards ought to be thoroughly viable with, a PCB format made by the designer utilizing PCB designing software. The used PCB design software incorporates; Altium Designer, OrCAD, Pads, Ki CAD, Eagle, and among much others (NOTE: Before PCB creation, planners ought to illuminate their contract manufacturer about the PCB design software adaptation used to plan the circuit since it maintains a strategic distance from issues brought about by disparities.)
  • When the PCB configuration is endorsed for creation, creators send out the plan to design their producers’ support. The most often utilized program is called broadened Gerber. Gerber additionally goes by the name IX274X.

Gerber document

  • The PCB business birthed expanded Gerber as the ideal result design. Different PCB design software perhaps calls for various Gerber record age steps, they all encode complete essential data including copper following layers, drill drawing, gaps, part documentations, and different choices. All parts of the PCB configuration go through checks now. The product performs oversight calculations on the plan to guarantee that no mistakes go undetected. Developers likewise inspect the arrangement concerning components connecting with track width, board edge dividing, traces, and opening gaps and size.
  • After a careful design process, the designer forwards the PCB to PC Board Houses for creation. To guarantee the plan satisfies necessities for the base resistances during the assembling process, practically all PCB Fab Houses run Design for Manufacture (DFM) checks before circuit board creation.
  1. From File to Film

  • PCB printing starts after the designer yield the PCB schematic documents and producers conduct a DFM check. Producers utilize an exceptional printer referred to as a plotter, which makes film images of the PCBs, to print circuit boards. Even though it’s a laser printer, it is not a LaserJet printer. Plotters utilize unquestionably exact printing tech to give an exceptionally definite film of the PCB design.

PCB dark ink

  • The eventual outcome brings about a plastic board with a photo negative of the PCB in dark ink.
  • For the internal layers of PCB, dark ink addresses the conductive copper portions of the PCB. The leftover clear part of the picture indicates the areas of non-conductive material.
  • The external layers follow the contrary example: light for copper, yet dark alludes to the area that will be scratched away. The plotter naturally fosters the film, and the film is safely put away to forestall any undesirable contact.
  • To accomplish the ideal arrangement of all films, registration openings ought to be punched through all films.
  • The precision of the opening happens by changing the table on which the film sits. Whenever the minuscule alignments of the table lead to an ideal pair, the opening is punched. The openings will squeeze into the enlistment pins in the subsequent stage of the imaging system.
  1. Printing the Inner layers of the PCB

  • The formation of films in the previous step plans to delineate a figure of copper way. Presently it’s an ideal opportunity to print the figure on film onto a copper foil.
  • This progression in PCB production prepares us to make genuine PCB. The fundamental type of PCB involves a cover board whose center material is epoxy gum and glass fiber which are likewise called substrate material.
  • Overlay/lamination fills in as an optimal body for getting the copper that structures the PCB. Substrate material gives a durable and dust-safe starting stage for the PCB.
  • Copper is pre-fortified on the two sides. The cycle includes shaving away the copper to uncover the plan from the films.
  • In PCB development, high standards of cleanliness are considered. The copper-sided cover is cleaned and passed into a disinfected environment. During this stage, no residue particles must be on the cover. A deviant bit of dust could make a circuit be short or stay open.
  1. Removing the Unwanted Copper

  • With the photo negative eliminated and the solidified resist covering the copper we wish to keep; the board continues to the following stage: undesirable copper removal.
  • Similarly, as the soluble arrangement eliminated the oppose, an all the more remarkable synthetic planning consumes the abundance of copper.
  • Not all copper sheets are made equivalent. A few high-density boards require bigger measures of copper solvent and differing lengths of holes. As a side note, heavier copper sheets require extra consideration for track spacing.
  • Now that the solution removed the undesirable copper, the hardened opposed safeguarding the favored copper needs washing off. Another solvent achieves assignment. The board currently shimmers with just the copper substrate essential for the PCB.
  1. Layer Alignment and Optical Inspection

  • With every one of the layers clean and prepared, the layers require arrangement punches to guarantee their alignment. The openings adjust the internal layers to the external ones.
  • The expert places the layers into a machine called the optical punch, which allows a definite correspondence so the enlistment openings are precisely punched.

  • When the layers are set together, it’s difficult to address any mistakes happening on the internal layers. One more machine plays out a programmed optical inspection of the boards to affirm an all-out shortfall of deformities.
  • The first design from Gerber, which the producer gets, fills in as the model. The machine checks the layers utilizing a laser sensor and continues to electronically contrast the computerized picture and the first Gerber record.
  • Assuming that the machine observes an irregularity, the examination is shown on a screen for the specialist to survey. When the layer passes the assessment, it moves to the last phases of PCB creation.

New Trends in PCB manufacturing.

The internet of things technology is growing very fast in every sector and the world is realizing that it is very important for every electronic gadget to have it. Similar initiatives are happening in the area of printed circuit board design.

  • For PCB design, if you are not embracing the most recent technologies, we expect you to come across too many difficulties.
  • In the beginning, you might start with low volumes of the PCBs to act as prototypes and testing specimens before you can proceed to mass production of the same.
  • Below we shall look at the most available types of PCBs patterns that you might encounter in the market.

Trend 1: High-Power Boards now in High Demand

  • The modern-day innovation has moved a notch higher by allowing the manufacturers to make the high power voltages printed circuit boards that are av]ble to hanf]dle power of up to 48 volts
  • This type of board is capable of wori]king with the multiples of the gadgets that are available.

Trend 2: PCB Auto placers

Autoplacers are very important in the proves of PCB manufacturing and are always remembered by the PCB manufacturers

  • It is a computerization method that has made it more proficient in the process of electronic gadgets production.
  • The auto places have improved the operational speed and quality of adverts.

Trend 3: Biodegradable PCBs

  • The issue of electronic waste has become a global crisis. To make sure that we solve this issue, it has necessitated the introduction of biodegradable PCBs to replace the non-biodegradable ones.
  • The disposal of PCBs especially from electronics was a source of pollution to our environment.

Trend 4: Flexible PCBs

Internet of Things e

  • The adaptability of the PCB is very vital as it helps in dealing with a few capacities.
  • it might not surprise you that the adaptable printed circuit boards are getting more demand than the fixed ones. The other name for the adaptable PCBs s flexible PCBs.

Trend 5: High-Density Interconnect

  • High density interconnects (HDI) was created in light of the interest for increasingly small items with more noteworthy capacity, particularly as far as controls.
  • This ability takes into account fewer layers in the PCB stack-up and advances fast sign transmission.
  • HDI production faces difficulties with manufacturing vias to such an extent that several vias might be directed inside a small region, which presents issues like noise and impedance.
  • To expand this idea, each layer interconnects (ELIC) and any layer interconnect (ALIC) ought to be seen with developments throughout the next few years.

Trend 6: The Need for Energy-Efficient Electronics

  • Natural worries are crucial during the creation cycle as well as all through the lifecycle of the gadgets. Limiting energy utilization is a progressive approach to lessening costs, making organizations and buyers go for low-energy consuming contraptions.
  • Electronic manufacturers should embrace green creation processes while simultaneously making contraptions that center pay workers can manage.
  • The pattern towards energy-effective hardware has prompted an appeal for related advancements, similar to voltage manager ICs. It is projected that expanding energy utilization worldwide will make shoppers embrace energy protection measures, such as utilizing low-energy utilization gadgets.

Trend 7: Fashioning Strategic Partnerships to Minimize Production Costs

  • A review led by Price water Coopers (PwC) laid out that agreement creation is going through a huge change. As Original Equipment Manufacturers (OEMs) progressively contract out item designs and advancement to Electronics Manufacturing Service (EMS) organizations, they are limited by large usage and transform fixed costs into variable expenses, a huge part of controlling manufacturing costs.
  • This pattern presents possible open doors for EMS organizations to empower them to wander into new business lines and extend their income margins. Most PCB producers are thinking about coordinating administrations that create more profit. According to a fashioner’s point of view, they are thinking about giving more plan administrations to sub-congregations and final results. According to a quality point of view, they are extending their quality testing limits. For the most part, the more administrations they give, the more they adventure into shared plan PCB producing (JDM) and old design manufacturing (ODM).
  • While fashioning key associations is monetarily valuable, you should consider a few variables to partake in those advantages. EMS and OEMs should assess their current client and item portfolios, adjust their techniques to plans of action well, and survey incentives to guarantee they line up with purchaser requests and the executives’ choices.

Trend 8: The Need for Green PCB Manufacturing

  • Becoming environmentally friendly isn’t just directed to hipsters and displeased Xers right now. As the world keeps on feeling the effect of climate change, shoppers, countries, and non-legislative associations are placing more strain on manufacturers to move to green production strategies.
  • Additionally, ecological offices across the world are carrying out carbon exchanging procedures, driving green manufacturing further.
  • With fabulous plans in progress to drive research in green assembling, manufacturers who will be ISO guaranteed will see a great deal of interest, even in districts that are not at the lower furthest reaches of the creation cost scale.

Trend 9: The Internet of Things (IoT)

  • IoT is a multi-layered plan that calls for speedy correspondence among layers and parts. This innovation is generally applied in running keen homes and work environments and in remote checking and control. The primary assembling issue for IoT printed circuit boards is accomplishing various principles and guidelines that characterize their creation.

Trend 10: The Demand for Smart Devices Continues to Increase

  • Brilliant hardware, for example, cell phones and wearables, are sought after at this moment. However contraptions like cell phones have been present for a very long time, their capacity to associate with shrewd homes, workplaces, and self-driving vehicles is a recent fad. This pattern will speed up essential organizations between PCB makers and state-of-the-art tech specialist co-ops to smooth out the production of savvy gadget PCBs.
  • For innovation specialist organizations, this pattern opens more income creation streams. In any case, PCB producers are confronted with the test of getting secure, adaptable, and associated gadgets into the market, taking into account that the availability idea isn’t their area of specialization.
  • PCB producers should be adaptable and versatile to be on the ball in the always-changing electronic requests. They can profit from these changing customer patterns by embracing functional changes and fostering an artful mentality among their laborers. Specialists accept that advancement can forestall a sliding pattern in deals in created item classifications like PCs and TVs.

Trend 11: Commercial-Off-The-Shelf Solutions (COTS)

  • The commercial off-the-shelf solution (COTS) refers to products already available in the market for use. They incorporate Printed circuit parts, and boards that come “with no guarantees.”
  • Aviation is an industry where we see PCB innovation use COTS often. For instance, new space improvement solutions are executing PCB COTS to decrease the expenses of significant drives while guaranteeing quality and security all while finishing projects quicker.


We have examined the current top PCB trends that will extensively shape the electronic business in the coming years. The above-examined patterns could confront a few difficulties and also leave scope for development, where new advances are created.

These patterns will proceed with the development of printed circuit board fabricating technology. The fate of the circuit board industry is brilliant and will be getting rid of the side-effect in their performance and scaling down. Moreover, being naturally cognizant and controlling creation costs will assume a major part in molding the eventual fate of this industry.


Introduction to Rigid-Flex PCB


Due to technological changes, the type of assembly steps and materials used in any production tends to change. The change experienced is either a change that will bring solutions to a market or create a foundation for the next technology. Rigid circuit boards existed in the market place and they were doing quite well. Later rigid-flex circuit boards were introduced. They were designed to provide solutions and act as a replacement for rigid printed circuit boards. Rigid-flex circuit boards, as the name suggests, are a hybrid of flex and rigid circuits. This technology ensured that it serves both the rigid and the flexible parts. Many years ago before the invention of printed circuit boards, electronic circuits existed as flexible and free-wired, with possible additional use of solder strips. Mechanical anchorage points were components such as potentiometers, variable capacitors, switches having their solder lugs, and socket electron tubes.

In this article, we are going to talk about rigid-flex printed circuit boards. Everything, from design, applications, advantages, and many more.

How Rigid-Flex PCB came to Existence

  • Before the introduction of rigid-flex PCBs, the existed the rigid PCB. This was a solid printed circuit board that was not flexible. This type of circuit board could not be bent or forced out of shape it was a solid-state board.

  • The trend in aerospace products development includes miniaturization lightweight, multifunction, assembly densification, etc, a high requirement was seen being startup for PCB technology and the process of manufacturing.
  • A flexible printed circuit board is a type of electronic circuits board that is made of a flexible substrate substance featuring more advantages compared to rigid printed circuit boards. They include;
    • Smaller thickness
    • Lightweight
    • More space was saved
    • High freedom in electronic and mechanical design
    • Bending feature
  • It was made of a solid substrate having copper tracks and components layouts where through-hole components, surface mount devices, and mixed PCB assembly could be soldered either automatically or by use of through-hole technology.
  • These flexible PCBs are used everywhere since they can fit in any housing. They just need some folding to fit in the space available.

  • Later designers realized that they needed a printed circuit board that was more advantageous to them and that’s how rigid-flex printed circuit boards came into existence.
  • The combination of both the rigid and flexible PCBs brought so many advantages for the user in terms of signal transmission, size assembly, stability, and many more.
  • Electromagnetic signals are capable of running faster and softly for flex PCBs because of the perfect electrical and thermal performances of the flexible substrate materials. The flexibility is widely used in many manufacturing areas such as; instruments, automobiles, medical care, aerospace, and military
  • Due to further development of flexible printed circuit boards, their next step should be the Rigid-Flex printed circuit boards, the HDI Flex PCBs, and embedded flexibles amongst which Rigid-Flex private circuit boards attract the most applications.

Materials used in Rigid-Flex Printed Circuit Boards Technology

  • When it comes to the rigid-flex PCBs performance, it will always depend on the substrate material that flexible dielectric, and flexible adhesive films.
  • Flexible dielectric films contain;
    • Polyester (Mylar) is common for products of low-end.
    • Polyimide (Kapton) is the most common type.
  • Fluoropolymer (PTFE) for aerospace and military products

When the three flexible substrate materials are put into comparison, polyimide will feature the topmost dielectric constants with excellent mechanical and electrical properties and resistance to high temperatures. Almost similar to polyimide when it comes to performance, polyester has bad high temperatures resistance.

  • Fluoropolymer or Polytetrafluoroethylene (PTFE) is used in products with high frequencies accompanied by the low constant of the dielectric. Their performances can be demonstrated in the table below:

Types of Rigid-Flex Printed Circuit Boards

Only two main types of rigid-flex PCBs are existent in the market or are rather popularly known.

  • Flex to install

This board only folds once when the device is removed or assembled for the first time. The flex part remains stable throughout usage, besides some movements that might occur in case of high oscillation applications are experienced.

Flex to install

  • Dynamic flex

This printed circuit board is a special category of the rigid-flex PCB family. It can be folded and bent many times as per the design or the product needed during the end product phase. This type requires special consideration to ensure the flexible portion of the board can withstand repeated wear and tear. If proper design procedure is followed using the correct bend radius, dynamic flex can be bent over ten thousand times.

Manufacturing Technology of Rigid-Flex PCBs

Technologies used to manufacture every PCB tend to differ from each other. It depends on the type of PCB one needs and the performances they require it to deliver. In the case of rigid-flex PCBs, there is a difference in the fine circuit manufacturing technology and the micro via manufacturing technology. Since every electronic equipment and product is developing towards lightweight and miniaturization, multifunction and assembly densification, advanced printed circuit boards are attracting the most attention including rigid-flex PCBs, HDI flex-rigid PCBs, and embedded flex-rigid printed circuit boards.

  • Rigid-flex PCBs are fabricated through selective and orderly layer stack-up of flexible PCBs and rigid PCBs with plated through holes technology responsible for the connection between its layers.
  • The advent of rigid-flex PCBs can very effectively lower electronic products’ volume and their quality. They can enhance this by replacing harnesses and connectors that were applied in traditional electronic products. In addition, rigid-flex PCBs are capable of solving contact and intense heat problems caused by harness and connectors, rapidly improving the reliability of these devices.
  • From the 1970s, rigid-flex PCBs were built by stacking up the rigid boards onto the flexible boards. Several signs of progress and optimization have experienced new and numerous flex-rigid printed circuit board manufacturing technologies.
  • For flexible substrate material, the polyimide (PI) double-layer plate covered with a copper layer is used as a flexible core and polyimide film is applicable to give protection to the flexible circuits. Adhesion will depend on the low flow and all the components are laminated for the printed circuit board to be manufactured.
  • equipment volume and quality are reduced so that they are greatly applied in electronic devices that need to be bent over and over again.
  • The flexible substrate material features excellent dielectric stability that they are fit for higher frequency signal transmission and independence control. It can also withstand radiation, temperatures, shock, and extreme environments. The dielectric ensures the smooth running of electronic devices.
  • Additional conductive layers use either flexible or rigid insulation. This depends on the product’s requirement specification. The outer layer on the boards despite their price contains exposed pads to ensure safety. Here conductors are used in the primary hard or rigid layer, while in the flexible plates through-hole technology is used for any additional layer of the flexible and rigid layer.
  • Other projects need traditional rigid technology and design, while others contain restrictions that prevent manufacturers from using the larger, less flexible boards. An example; if standard board design is used, portable devices and mobile will be affected. Very many moving parts and components don’t perform well when subjected to certain conditions. On the other hand, mobile devices need to be portable, have lighter weights, and can withstand harsh conditions such as cold, heat, and humidity at times.

Rigid-flex Design

  • The manufacturing process of the rigid-flex printed circuit boards nearly resembles that of the old hardboard circuit, but some layers are flexible circuitry running through the hardboard. The fabricator adds plated through-holes in order to make connectivity to the layers of the rigid circuit regions of the flexible circuit.
  • Some of the configurations will create the rigid-flex printed circuit board that is assembled just like the hardboards, but it is also able to fit in the product that has space constraints.  This makes them most used for continuously flexible applications which are also called dynamic flex applications. If rigid-flex PCB is well designed, it is capable of withstanding millions of flex cycles without a single failure. The flexible and the rigid substrates will form a single integrated unit which can be manipulated further to a three-dimensional subassembly.
  • It is very important at times to distinguish between rigid-flex and flex PCBs with stiffeners, which at times it can be used for the same applications. Stiffeners used on flexible circuits will always provide the required stability for the assembly.
  • Rigid-flex PCBs make the manufacturing process easier while giving a much high density for electronic components and schematic/ circuit routing. When this is not required, flex boards that have stiffeners might be enough and less expensive too.

  • Rigid-flex printed circuit boards can be quite more costly than their comparable hardboards. Their prices are usually twice or even thrice the cost of a flexible circuit that has a stiffener. Moreover, its high cost is justified by where it finds its application specifications and environments which include:
    • Highly reliable applications; in case an assembly might be exposed to too much or looping shocks, or high environmental vibrations, connectors that have flexible cables are most likely to be destroyed. Rigid-flex printed circuit boards offer high reliability even when it’s subjected to excessive environmental vibrations.
    • Highly dense applications; on very small enclosures, it’s very impossible at times to attach all the cables, components, and connectors that an electronic printed circuit board can be folded to very small shapes, offering wonderful space saves for these instances.

Production Flow

Since the soft and hard bonding board is a combination of both the flex PCB and the rigid PCB, the production of the plates should have both the FPC equipment of production and PCB equipment of production.

  1. First of all, electronic designers and engineers draw a trace and layout of the soft bonding plate with respect to the requirement specification.
  2. After the drawing part, the drawing is then forwarded to the flex-rigid PCB factory or production units. The fabricator deals with and plans the necessary documents and arranges the FPC manufacturing line to generate the required FPC, PCB line of production to produce PCB. The two soft and hard boards are then produced by the plan’s requirements of electronic and electrical engineers.
  3. Here there are several detailed inks. This is the final part of or rather the final process for the production of the soft and hard plates. It is one of the most important parts. The flex-rigid printed circuit board is tested. So many details are needed to be confirmed before shipping is initiated. Generally, a full smart inspection is carried out. This is done to allow the supply and the demand to cause the loss of related benefits, so the value is relatively high. Below is the manufacturing flow of the flex-rigid PCBs.

Advantages of Rigid-flex Printed Circuit Boards

The combination of flexible and rigid boards makes it an extremely beneficial product for both applications as well as to the customers. Some of the advantages include:

  • Dynamic stability: Rigid-flex circuit boards fives the customer the liberty of packaging geometry while retaining the precision density and looping of printed circuits.

  • Money saving and space: Using rigid-flex circuit boards can bring an immense reduction in total computer circuit boards costs and expenditure. However, rigid-flex PCBs are costlier compared to flexible PCBs and rigid PCBs, but their assembly charges are less. this is often thanks to their small sizes and also the few connections in them. Rigid-flex computer circuit boards hence require less material for assembling. The few parts and connectors during assembling don’t only increase the yield but also reduce the acquisition and assembly costs of the ultimate product. Having a reduced number of connections also eliminates the risks within the logistics of a device. In simple terms, logistics and assembly costs are reduced when it involves rigid-flex computer circuit boards.
  • Security: Rigid-flex computer circuit boards provide secure connections for other components, providing stability and polarity. These circuit boards also help to scale back the number of connector components in an application.
  • Mechanical stability: The circuits tend to own an interchanging factor for the layer which forms a powerful foundation. Flexible boards will give the flexibility required for installation in small spaces while rigid boards will give stability.

  • Flexible design option: Rigid-flex computer circuit boards are often significantly deformed to any shape with no breakage. Its standard materials can withstand as many bending cycles as possible. thanks to the 3D design and therefore the multiple layers of flexible circuits, the rigid-flex computer circuit board offers increased flexibility to suit small devices. In summary, you don’t need to specifically design a tool in keeping with the desired specification of the PCBs as within the case of the rigid boards. The corners of the rigid-flex PCBs are generally to supply a versatile connection. it’s also possible to feature rigidness in its design when extra mechanical support is required.
  • Reduced packaging size: Product miniaturization has been applied in rigid-flex computer circuit boards thanks to the compacted size of the circuited boards. it’s easily manufactured to suit small electronic devices, that’s why it’s used is in designing several sophisticated circuits. Here the electronic devices are designed to be smaller in size and more versatile, so they fully serve the necessity of proper connection of small components. Thus it is often folded or bent to smaller devices and it’s also lightweight thanks to its small size.
  • Repair and maintenance are convenient: 3D designing has made the repair and maintenance easier and it’s not a tiresome task, unlike for rigid or flexible boards. The rigid-flex board is bent, folded, and twisted allowing technicians to mend and touch the issues anywhere they’re diagnosed during troubleshooting easily. Besides, the connection between rigid and flex sections is thru the board to board connectors, hence the circuit is evident and simple to debug. This makes it easy to detect the fault within the rigid-flex board and repair it during routine maintenance.
  • High chilling and aggressive conditions: Polyimide being the substrate material that’s used, has high thermal stability. This material can withstand high temperatures. Hence the rationale it’s suitable for stylish applications for military and defense purposes. It can retain the most effective features for both rigid and flex boards, and so it demonstrates extreme resistance to ultraviolet and radiation exposure and even harmful chemicals. it’s also ready to withstand environmental shocks and vibrations with other harsh conditions from the industries.

Applications of Rigid-flex Printed Circuit Boards

These types of circuits are found and applicable anywhere due to the technology used in every field. Some of the areas where its applications include;

  • Commercial applications
  • Military applications
  • Industrial applications
  • Digital cameras
  • Cell phones
  • Smart devices
  • In the medical industry, they are used to develop pacemakers for weight reduction, space, and flexibility.


Traditional rigid-flex computer circuit boards are hard to manufacture since there’s a comparatively low yield rate and high density and are difficult to repair if there’s a breakdown. within the manufacturing process, the rigid plate requires to be embedded into a fashionable flexible substrate material so that the staple waste rate remains high hence manufacturing technology is difficult. The substrate material contains a comparatively high coefficient of thermal expansion and high moisture absorption rate of large-area flexible substrate material, resulting in size tolerance accumulation. this may further affect circuit pattern, drilling, layer up, plating, and cleaning which results in a lower yield. Circuits that have embedded flexibility are capable of effectively reducing and avoiding the above-mentioned issues.

Rigid-flex PCB brings about the main explanation for rising costs, meaning raw materials and products should be utilized. If technicians, designers, and engineers can cooperate within the first stages of the project design, they’ll make sure that design work is completed at an occasional price hence avoiding excessive and unwanted costs.


Introduction to LED PCB



  • They are printed circuit boards (PCBs) that are mainly made for LED circuits since they produce a lot of heat energy. They are also known as Driven PCBs. Driven PCBs are metal-based MCPCBS having aluminum as their substrate thus having great warm conductivity.
  • Driven PCBs are made of an extraordinary slender layer of thermally conductive material that releases heat rapidly when contrasted with the standard PCB sheets. Aluminum is the preferred material utilized in LED circuit sheets.

  • We have different types of LED PCBs which include;
  • Flexible LED printed circuit board.

  • Rigid (unbending) LED printed circuit board. It is firm and inverse to the adaptable.

  • Hybrid LED printed circuit board which consists of non-warm material alongside a metal base.

  • Multi-layer LED printed circuit board that contains more than one layer.

Evolution of LED PCBs

As PCB has kept on developing, it has made ready for the formation of a large group of invigorating item advancements. A great representation is the advancement of the (printed circuit board) PCB for LED lighting. The LED is bound to the circuit board and elements a chip that creates the light when electrically associated. A warm heat sunk and an artistic base is utilized to bond the chip.

A LED PCB board will try to produce a high volume of hotness, making it hard to cool through ancient means. However, metal center PCBs are habitually picked for LED application because of their improved capacity to disseminate heat. Specifically, Aluminum is frequently used to fabricate circuit sheets for LED lights. The aluminum PCB (printed circuit board) commonly incorporates a slim layer of thermally conductive dielectric material that can move and scatter the hotness with a lot more noteworthy effectiveness than a conventional unbending printed circuit board.

Design of LED PCBs

  • Driven PCBs have a significant and practically imperative part in current life. LED PCBs mostly are found all over the world. An innovation because of the mix of ‘Light Emitting Diodes or LEDs onto ‘Printed Circuit Boards’ or PCBs, they are a fascinating and practically imaginative piece of innovation, which reformed gadgets.
  • They offer a wide scope of benefits like minimal expense, high proficiency, underlying strength, etc; they immediately tracked down their direction into a wide scope of uses. However, the actual innovation has begun to go through changes, given the innovative work in progress to improve things. Coming to the planning part of these LED PCBs, there are a few distinct viewpoints that are thought about them.

Assembling of LED PCBs

  • Driven PCB gathering has changed the universe of lighting thus nowadays you will observe LED PCBs any place lighting is needed. It is like when contrasted with other lighting innovations. The innovation is advancing step by step with the expanding interest for LED Light Circuit Board Assembly.
  • In today’s world, the LED PCB gatherings are of more strong, durable, and high-performing power. Driven lighting is liked over conventional fluorescent lights and glowing lights.
  • While there are still applications utilizing CEM 3 and FR 4 material to fabricate LED PCB, Furthermore, the most famous LED PCB base material is as yet metal center PCBs, like aluminum and copper elements.
  • Driven PCB get-together can be confusing since metal center PCBs( aluminum and copper compound) are intended to direct heat away from patch cushions since aluminum and copper have great execution on heat move. If your LED PCB gathering process is not calibrated, the resultant outcome can be loaded with problems like unfortunate bind joints, LED misalignment, and pointing bumbles (blunders).

  • A great deal of LED PCB gathering organizations experience issues setting a large number of the LEDs beneath.

Types of Aluminum used in assembling LED PCBs

There are different types of aluminum used in assembling these PCBs which are;

  • Adaptable aluminum. This comprises earthenware fillers and polyimide tars which give better protection and adaptability to the LED PCB.
  • Crossbreed (hybrid) aluminum.FR4, a non-warm material is converged with aluminum metal. This assists in making the LED PCB inflexible. It also conserves its warm trademark. Crossbreed aluminum has some advantages which are:
  • Less expensive development cost when it is compared with utilization of all warm conductive materials.
  • Has better heat dispersal contrasted with FR-4products?
  • Does not have any expense for heat sinks since it does not have it.
  • Multi-facet (multi-layer) aluminum. High heat move and viable warm conductivity are intensely required in extremely complex LED PCBs. Due to these lines, multi-facet aluminum is extremely important for such. They are relevant here because LED light PCBs consume less power. However, they have no mercury, work productively and endure longer when contrasted with different light PCBs.

Application of LED PCBs Assembly

  • The LED PCB Assembly method has been applied in media communications, Automotive, Computer, and clinical hardware.

The core construction of LED PCBs

Contingent upon the utilization of the board, PCB producing includes utilizing different materials, plans, and arrangements. Quite possibly the most basic viewpoint is the material making the center out of the circuit board.

Some common core PCB materials are:

  • FR-4: FR-4 is made up of glass and epoxy and is quite possibly the most well-known center material. It is fire-retardant, yet not particularly effective at moving hotness.
  • Epoxies: Epoxies are another normal choice. They are not generally much tough as other center materials, yet they cost less to fabricate.
  • Profoundly: Metal-center PCBs frequently is made up of aluminum alloyed with different metals and overlaid with copper. These materials are valuable for applications including heat moves and deal with amazing warm conductivity and electrical protection.

Due to the fundamental work of hotness move in LED PCB applications, metals, particularly aluminum and copper are the most well-known LED PCB materials.

Aluminum LED printed circuit board

Aluminum PCBs are the most well-known sort of LED PCB. These sheets sit on an aluminum combination base, which regularly comprises aluminum, magnesium, and silicon. These LED PCB materials adjust the properties of the material to help in addressing the requirements of every application.

The layers that aluminum PCB has are as follows;

  • The base layer: It incorporates an aluminum composite sheet, and is the layer the remainder of the PCB sits upon.
  • The warm protection layer: The warm protection layer is made up of a ceramic polymer and shields the board from warm and mechanical harm. As the current goes all through the circuits, this layer retains any hotness emitted and moves it to the aluminum layer, where it scatters.
  • The circuit layer: This layer entails the copper circuits spread out as shown by the LED PCB’s circuit plan.

There are different kinds of aluminum LED PCBs, which offer various attributes that make them ideal for different applications. Examples are;

  • Adaptable aluminum: Flexible LED PCBs are made up of aluminum, polyimide sap, and earthenware fillers, which give it, expanded adaptability and protection while holding the aluminum’s warm conductivity. You can flex these PCBs to interface them, taking out what is needed for connectors, links, and different installations. More so, their plan empowers them to twist once and get set up, rather than flexing continually. These sheets vary from the standard inflexible sheets, which do not twist.
  • Crossover aluminum: Coming up with these kinds of sheets includes combining an aluminum base metal with a non-warm material, for example, a traditional FR-4 board. Utilizing this sort of board lowers expenses and increments unbending nature while offering great hotness dissemination.
  • Multi-facet aluminum: Multilayer aluminum PCBs have multiple layers consisting of thermally conductive dielectrics. These sheets empower elite execution, while as yet giving successful hotness scattering, although they are less viable at moving hotness than a few different sorts of sheets. These sheets vary from the less complex one-and two-layer PCBs.

There are two ways used in assembling LED PCBs which are;

  • Surface-mount: The surface-mount technique includes mounting parts straightforwardly onto the board’s surface. This exceptionally computerized process offers superb adaptability and takes into account high association densities, which is valuable for LED applications. The interaction includes putting weld glue on the board, setting the parts utilizing a pick-and-spot machine, warming the board to make the patch joints structure, and assessing the board to guarantee it works more accurately. Surface-mount LED circuit sheets assume parts in various applications, particularly those that require complex hardware in little gadgets.
  • Through opening gathering: Thru-opening get-together includes penetrating openings in the PCBs, then, at that point, running parts called leads through these openings. Then, at that point, the constructing agent applies weld to hold the pieces set up. The cycle likewise includes various examinations to guarantee exactness and viability. This strategy gives more grounded, stronger associations which are more useful for gear that will experience more outrageous conditions and applications, like high rates or high temperatures.

Benefits of LED printed circuit boards

Driven lighting and LED PCBs to offer various advantages that make them helpful in numerous applications. Some of these advantages are;

  • Diminished power utilization: LEDs use around 75% less energy than radiant bulbs, as indicated by the company’s logo.
  • More Efficient: Incandescent lights emit around 90% of their energy as heat. LEDs also produce a small amount of heat and that implies more energy goes into the ideal impact of creating light and less gets squandered as hotness. With non-LED lighting, reflectors should coordinate light in the ideal bearing, and a portion of the light never gets installed. LEDs also discharge light in a specific heading, which makes it more straightforward to send it where you want it to go and guarantees every one of the light leaves the apparatus.
  • Little size: LED lights are more modest than different sorts of lights, so they can work in little gadgets like cell phones and as minuscule pointer lights. They do also have the flexibility to be helpful in bigger applications, for example, traffic signals and spotlights.
  • Without or no mercury: LED lights do not contain poisonous mercury-like different sorts of lighting do. This quality makes them more secure, all the more harmless to the ecosystem, and simpler to discard.
  • Diminished costs: The expanded effectiveness and longer existence of LEDs implies decreased costs, as you will utilize less energy and you need to buy bulbs on rare occasions.
  • Ecological friendly: LEDs utilize significantly less energy than different sorts of bulbs. Since they last longer, they make less waste.
  • It has no harmful mercury: LED lights do not contain harmful mercury like different sorts of lighting do. This quality makes them more secure.


Problems or disadvantages of LED PCBs

  • Wrong use of currents. Change in current can straightforwardly affect the lifetime of a LED bulb. LEDs are subject to steady and predictable current and as a result, a current rush can be very harmful. For instance, screwing a LED light in a while it is as yet turned on can blow the bulb’s semiconductors. This can likewise occur on the off chance that your LED light is turned here and there time after the other which can bring about a current rush past the normal boundaries.
  • Overheat LED bulbs. Letting LED bulbs overheat will make them rashly fall flat. The only rule you can never disregard and keep up with your LEDs is that they should be kept cool. Many individuals experience issues with LEDs when they put them in nearness to different bulbs. The hotness produced by these different bulbs can make your LEDs fall flat.
  • Bad quality- patches and wire bonds. Whenever you buy a LED bulb from a believed producer they should be have been put through a progression of thorough tests. Furthermore, it’s almost certainly correct that any of the patch wires or different parts in the bulb is of sufficiently high quality. Without this testing, there will be a probability that the bulb will keep going as long as it states.
  • Inappropriate use of LED lighting. Wrong use of LED lighting can lead to harmful results thus damaging the lighting material or object.

Factors to be considered while designing a LED PCB board

While planning a LED printed circuit board, you should keep in mind how to utilize the materials, how to oversee heat, follow directing, and completion. With appropriate courses of action, a PCB creator can come up with a board that will fill in as it should for working the LED. Some of factors are;

  • Materials utilized for the printed circuit board (PCB) should work together to eliminate and disperse additional hotness, protect transmitters, and permit electrical associations between LED (driven) parts. The base layer for some, LED circuit sheets uses aluminum in small quantity. Over the aluminum base is the dielectric layer, stuck by the copper circuit layer and the tight spot cover. This sort of arrangement similarly goes by the term safeguarded metal substrate (IMS). The aluminum base functions admirably to deliver additional hotness and aid warm administration.
  • Thermal administration. Warm administration is one of the most pivotal parts of the LED plan. Inadequately managed temperatures can abbreviate the existence of the gadget and influence the shading virtue of the light. Along these lines, plans of LED circuit sheets regularly incorporate aluminum centers and hotness sinks to move much hotness away from the parts as could reasonably be anticipated. The part plan and LED arrangement likewise sway the conveyance and expulsion of hotness to the air and ought to be essential for the plan contemplations.
  • Appropriate follow steering plan. Legitimate follow directing arrangements forestalls open and short-circuits, the crosstalk among circuits, and assembling issues. Adhere to steering guarantees that all network associations are properly appended without obstruction from other organization associations. Space for follows and mounting opening considerations in the arrangement also ensure that issues would not happen during gathering.
  • Finishing wrapping up. Finish of the sheets safeguards the circuit layer and ensures that social affair has a site for restricting parts onto. There are a couple of tests of printed circuit board total open, each with its advantages and limitations. Observing the right completion might include talking about the assumptions for the board and the spending plan for the undertaking.

SMT LEDs in a given PCBs

  • Numerous gadgets have LEDs for a PCB utilizing surface-mounted parts. Through-opening parts can twist marginally assuming the wires are extremely slim, making the gadget look modest from an external perspective. When SMD LEDs have fastened appropriately, they stay inflexible on the board. They can likewise be put behind a screen, though less expensive LEDs that utilize bulbs will stand out through the bundling. SMD LEDs can be put behind a little screen in your bundling, giving your gadget a cleaner look and feel.
  • Most PCBs that have LEDs are fabricated utilizing complex FR4 substrates. You will have to incorporate an example of intently dispersed filled and additionally plated through vias under every part to communicate heat, as well as arrive at your power and ground parts (layers).
  • A via called Vippo can be utilized on the off chance that your LEDs have a little impression and are surface-mounted. The patch can wick into these vias during get-together if these vias are not filled or plated over, coming about in a feeble bind joint or in any event, tombstoning. This issue with wicking is one motivation behind why it is smarter to simply utilize SMD LEDs on a LED lighting exhibit. VIPPO is a superior decision for other PCBs that incorporate surface-mounted parts.
  • A solitary LED with a nice power result would not make unjustifiable warm harm your PCB. In any case, assuming you are building a framework for lighting applications, the PCB that upholds your LEDs should persists a lot of hotness, and these sheets are challenging to cool through customary forms. You cannot append a heat sink anyplace as the singular LEDs are excessively little, and a heat sink would impede the radiated light in any case.
  • Because of the warm requests, PCBs with a metal center is generally utilized for LED lighting applications on account of their capacity to scatter a lot of hotness. Aluminum is frequently utilized as the metal center in PCBs that are utilized for LED lighting applications. However, Copper and iron are likewise utilized for metal center PCBs.

Trends and future of LED PCBs

  • The viewpoint for the LED lighting market stays extremely brilliant. Despite vacillations in the economy and the overall lighting industry, LED lighting keeps on involving a critical piece of the general lighting market now and then.
  • The DOE report Energy Savings Forecast of Solid-State Lighting in General Illumination Applications gauges the energy investment funds of LED white-light sources over the investigation time of 2018-2030. With reducing costs and further developing execution, LED items have been realized in expanding reception for general light applications. This is a positive advancement as far as energy utilization is done. LEDs utilize fundamentally less power per lumen created than numerous conventional lighting innovations.

  • LED PCBs have led to more and more advancements of technology.
  • The Internet of Things is spreading all over, and we have come to understand that each gadget should be shrewd in the advanced period. A similar direction is going on with printed circuit sheets (PCBs); pushing PCB planners to make incorporated and changed forms of their plans. Nowadays, we are seeing multi-facet and an assortment of low-volume PCBs.


PCB Heat Management Processes and Systems


Research has shown that out-of-control heat causes over half of all electronic system failures. Assuming that we can carry out good heat management, we can drastically drive down the number of electronic system failures.

As electronic gadgets keep on being scaled down, the heat demands in these frameworks increment as more features are pressed into more modest gadgets. This is particularly obvious in printed circuit boards (PCBs) that work at high current-carrying capacities. High output power systems, for example, Li+ ion cells utilized in electric vehicles, require an integrated power management system that is based on PCBs. Designers and producers should carry out innovative methodologies to oversee heat produced in a high current PCB design.

Thermal resistance is the distinction in temperature between two shut surfaces partitioned by the absolute heat flow between the surfaces. The level of heat resistance regularly relies upon PCB configuration factors. Utilizing surface mount parts affects positively by reducing thermal resistance. area and thickness of the copper foil on the PCB and the thickness and material utilized for the PCB have a more noteworthy impact. Essentially, more extensive and thicker materials disseminate more heat. However, constraints exist due to the standard utilization of materials and due to item details.

Printed circuit board thermal management techniques to reduce overheating

For effective thermal performance, PCB designers ought to consider the following heat management techniques;

  1. Marking thermal hot spots and high-current traces

  • To manufacture a thermally steady PCB, thermal impacts should be contemplated during the planning stage itself. The initial phase in the thermal plan is to distinguish the areas of interest.
  • Heat modeling and simulation strategies are utilized to track down areas of interest. Additionally, current flow examination should be done alongside it, since high-current follows cause generation of heat.

  • The legitimate statistical course of action of parts and high-current follows empowers even dissemination of heat. High-current follows should be steered away from thermally touchy parts, for example, sensors and Op-amps.
  1. The thickness of copper and width of traces

Consideration of width of traces for proficient PCB thermal management.

  • The thickness and width of the copper pads or traces assume a critical part of the PCB heat management plan.
  • Copper traces thickness ought to be satisfactory to give a low impedance path for current going through it.
  • This is on the grounds that the opposition of copper traces and vias represent huge power loss and thermal generation especially when they carry high current density. Along these lines, adequate trace width and thickness are prescribed to diminish thermal generation.


  1. Pad design for printed circuit board (PCB) thermal management.

  • Very much like trace thickness, pad thickness is additionally significant. Heat is disseminated straightforwardly towards the top copper layer. In this way, the top copper pad should have adequate thickness and surface area to give sufficient heat dispersion.

  • Assuming that the PCB configuration has heat sinks in it, they are normally mounted on the base copper pad. Then, at that point, the base copper pad ought to have adequate inclusion to permit the ideal thermal transfer to the heatsink.
  • The parts pin are bound to the PCB upheld by pads. The part is joined with the pad which brings about exceptionally low thermal resistance from the PCB. An exceptional welding pad, that is thermal pad is utilized on the circuit board. This pad is just associated with slender bridges to the copper-encompassing pour.
  • The patch glue used to join the part footprint with the thermal pad ought to be negligible.
  • An excessive amount of solder paste under the thermal pad can bring about the drifting of parts on a pool of liquid bind during reflow. At the point when this occurs, the part bundle will move. The answer to the drifting package issue is to improve the patch glue or solder paste volume.
  1. The setting of high-power components in PCB

  • For better thermal dispersal, high-power parts, for example, processors and microcontrollers ought to be put at the focal point of the PCB. Assuming that a powerful part is mounted close to the edge of the board, it will amass heat at the edge and raise the temperature. In any case, on the off chance that the gadget is put at the focal point of the board, heat will disperse over the surface in every direction. Hence the surface temperature of the PCB would be lower and disperses without any problem.

  • Likewise, ensure you have put high-power parts from delicate gadgets and keep an appropriate distance between 2 high-power gadgets. Attempt to put high-power parts uniformly across the PCB.
  1. PCB thermal vias layout

  • Thermal vias are heat-directing copper barrels that run between the top and lower parts of the board. Such vias are great heat conductors that move heat away from basic electronic parts. These vias are ordinarily used to work with fast heat dissemination away from surface mount gadgets (SMD).
  • Assume there is no space for a cooling framework on top of the PCB, as on account of a coordinated sensor, indicator, or a loaded board with various parts. The most straightforward method for scattering heat would be through thermal vias to the cooling system (heat sink/ heat pipes).
  • The number of warm vias under BGAs or processors ought not to be set in stone by the designers considering the heat dispersal reach and surface area. Standard thermal via parameters are as referenced below:
  • The distance across is 12 mil (0.3 mm) put on 25 mils (0.64 mm) lattice spacing.
  • Standard copper plating thickness is 1 mil (25 μm) with no via fills.
  1. Heat sink

  • The heat sink is a cooling technique that moves dispersed heat from PCB parts into a cooling medium. Heat sink deals with the principle of conduction which expresses that heat moves from an area of high thermal resistance to an area of low thermal resistance.
  • The heat additionally moves from high-temperature regions to low-temperature regions and how much heat flow is straightforwardly relative to the temperature contrast. The heat sink draws heat away from the PCB to blades that give a bigger surface region to quicker thermal dispersion.
  • PCB designers can pick a reasonable heat sink for their design in light of a few elements. For instance, the thermal resistivity of material utilized, the speed of cooling liquid inside the sink, the warm point of interaction material utilized, the number of blades and the space between blades, and the mounting method utilized.
  1. The integration of heat pipe

  • Heat pipes are cooling gadgets suggested for higher temperatures applications, for example, in rockets, satellites, and aeronautics. The heat pipes are for the most part accessible in an empty round and hollow shape, yet it very well may be made into any shape advantageously.

  • The heat dispersed from different gadgets is moved to the fluid inside the heat pipe and disintegrates the fluid. The vaporized fluid condensate at the condenser end and gets back to the evaporator through the wick structure by capillarity. This cyclic interaction guarantees the disseminated heat away from the PCB.
  • PCB designers ought to consider a heat pipe that covers their heat source and ought to have the option to twist according to your plan needs. There is a wide scope of heat pipe working liquids accessible, from cryogens to fluid metals. Working liquid determination relies upon the temperature scope of the circuit and the liquid’s substance similarity with the container and the wick of the heat pipe.
  1. Use of thicker printed circuit boards.

  • For more modest gadgets, cooling techniques like a heat sink, heat pipes, cooling fans are impossible by any stretch of the imagination. In such cases, the main choice is to build the thermal conductivity of the board and spread the created heat. Thick boards with a similarly bigger surface region can scatter heat rapidly.
  • The thermal conductivity of a PCB is resolved in view of the coefficient of thermal expansion (CTE) of the materials utilized and their thickness.
  • Designers should concentrate entirely on picking material for each layer in the PCB stackup. At the point when the coefficient of thermal expansion of the different materials utilized in various layers is bungled, (repeated thermal cycling) weakness happens to decrease the thermal conductivity. Copper plating in vias and solder balls are more defenseless against harm under high thermal cycling.
  1. Incorporated cooling techniques

  • Integrated cooling techniques are utilized to accomplish higher coefficients of thermal conductivity contrasted with customary heatsink and fan arrangements. The idea is to blow a cooling agent through vias straightforwardly to the lower part of the processors or BGAs or any heating parts.

  • The number of vias ought to be determined by the PCB designer, depending upon the thermal criteria of the mounted part. A solitary via is viewed as first, more can be added on request which relies upon the speed of the cooling liquid and the surface area of the part.
  • There are additionally different sorts of integrated cooling strategies, for instance, the inboard cooling strategy delineated previously. In this technique, a hotness exchanger is fused inside the actual board. Since no outer hotness sink or cold plate is required, the

  • PCB gathering steps and the heaviness of the result is decreased. However, these coolers require an exceptionally high warm through-thickness around the cooling channels.
  1. The soldering concentration.

  • The soldering thickness of component joints ought to be even and surrounding to decrease heat accumulation on the part leads. Additional consideration should be given while fastening close vias. There is an opportunity for the patch to overfill the opening prompting bumps on the lower part of the board and this diminishes the contact area of the heat sink.
  • PCB planners have two choices to keep away from the flood of a bind. The first thing is to diminish the breadth of the via underneath to 0.3mm. The more modest the vias, the surface strain of the fluid bind inside the via is better, ready to counter the power of gravity on the solder.
  • The subsequent choice is the interaction called tenting. It includes covering the stack of the via with a patch of soldering mask to keep the solder from streaming down to the via.
  1. Thermal simulation of printed circuit boards

  • A definite thermal simulation serves to exactly track down the temperature of a thermal hotspot in a PCB. Thermal simulation is the color scale guide of temperature in the heating area acquired under various circumstances. The unit of temperature in the simulation is degrees celsius(°C). The color scale maps are acquired by computing the temperatures of thousands of points from the circuit boards.

The reason why you should perform thermal simulation

  • To find hot areas of interest to stay away from the gamble of gadget failure.
  • Distinguish the conceivable dependability of dielectric material with different CTE values
  • Further develops item unwavering quality.
  • Warm reproductions can diminish the expense of execution by decreasing designing deferrals, field disappointments, and item emphasis.
  • Further developing execution and correspondence between the designing and electrical groups.
  1. Bigger PCB housing

  • Finally, a bigger PCB housing framework can be utilized for cooling too. Screws used to mount the PCB can fill in as effective heat flow paths to the framework body when the screws are thermally associated with spreader and ground planes.
  • The number of screws ought to be increased with the eventual result of unavoidable losses when contrasted with transfer impact and cost.
  • Metal PCB hardening plates can give an extra cooling region when joined with the heat spreading plane. For applications where the PCB is encased in a housing or other fenced-in area, a cavity filler material gives an improved thermal execution over an air-filled enclosure.
  • Cooling solutions, for example, fans and heat sinks are likewise normal ways of cooling a framework, yet regularly require extra space or design adjustments to upgrade cooling potential.


Common PCB cooling systems

  1. Fans for PCB cooling

  • Most electronic PCBs depend on cooling fans, with sizes ranging from 10-inch blowers to 8 mm miniature fans. A couple of heat plan conditions can limit the choice options. Early framework prototypes can assist with refining fan determination.
  • The intricacy of airflow implies that picking the right fan might require experimentation. A best practice is to begin the thermal plan from the start of the hardware prototyping.
  • Fans move the air by making a pressure differential. If the air is hindered, pressure develops, and no air moves. Assuming the fan is out in the open, there is no pressure across the fan, and the airflow is amplified. The working point is somewhere close to these limits.
  • One huge limitation of using fans as a method of PCB cooling is that some fans produce a lot of irritating noise during operation.
  1. Heat sink

  • A heat sink and fan (HSF) is a functioning chilling solution used to cool PCB. As the name proposes, it is made out of a passive cooling unit and a fan.

  • There are 2 types of heatsink namely; active and passive.
  1. Active heat sink

  • Active heat sinks use the PCBs power supply and may incorporate a fan. Now and then these kinds of heat sinks are alluded to as (HSF), heat sink, and fan. There are additionally fluid cooling frameworks, which have become famous lately.
  1. Passive heat sink

  • This type of heat sink is one that has no mechanical parts. Subsequently, they are 100 percent solid. They are made of an aluminum finned radiator that scatters heat through convection. For passive heat sinks to work to their full limit, there should be a consistent wind current getting across the fins.

  1. Liquid cooling system

  • A fluid cooling system is a method used to keep a PCB processor’s temperature low involving water as the cooling medium. This cooling system gives effective cooling and assists with limiting the clamor produced by higher processor speeds.

Types of liquid-cooled systems

  1. Integrated cooling systems

  • This cooling system, similar to its name, comes included as a component of a PCB housing.
  • As all of the fluid cooling gear is gathered inside the housing, presumably this is the least demanding choice to work with.
  • This is because it will normally give you the most room accessible inside the housing without having any outside parts to manage.
  1. Internal cooling systems

  • This cooling system has the water-cooling parts set inside the PCB housing.
  • This is because most PCB housings are not planned with this sort of system ordinarily, things may be somewhat clogged. As a benefit, this establishment permits you to keep your beloved case and to move the completed item around with less difficulty.
  1. External cooling systems

  • In this system, the radiator, supply, and pump are assembled remotely in a different unit.
  • As a functioning technique, the fluid coolant is siphoned into the PCB case, and in a return section, a return line pumps the hot coolant that was sent cold out of the case and into the supply.
  • The benefit of the external cooling system is that it bears the cost of the inside working space of a coordinated framework as well as can adjust to use with any ordinary case.
  • It takes into account a huge radiator and has more cooling power than some other incorporated solutions.
  • The drawback is that an exterior cooling framework isn’t quite as versatile as integrated or interior frameworks.

Step by step instructions to Identify Thermal Problems with Your PCB

Designers can utilize a wide scope of procedures to distinguish possible issues. Well-known approaches incorporate the utilization of thermal analysis instruments, visual assessments, and infrared cameras.

  1. Direct Thermal Analysis

  • Playing out a warm investigation lays out how the parts and PCB will act at various temperatures and conditions. The investigation furnishes creators with a thought of the hotness age and moves inside the circuit.
  • Architects can then utilize the analyzed results and reenactments to concoct strategies that will assist them with better heat management.

  1. Visually Inspecting the Circuit Board without Power

  • The visual investigation is a simple method for tracking down indications of overheating, by looking at burned or partially damaged parts, dry joints, arcing, and so on.

  • A portion of the apparent signs incorporates protruding parts, burnt parts, and stained spots on the PCB. Notwithstanding the visual investigation, a smell from the board can likewise highlight heating issues.
  1. Utilize Infrared Cameras

  • Test specialists can utilize IR cameras to assess powered prototype boards for thermal issues and distinguish issues imperceptible to the naked eye. As well as showing regions where there is an overabundance of heat, the cameras can once in a while distinguish fake or damaged parts whose heat signature contrast from those of genuine parts.

  • Thermal imaging cameras can likewise distinguish where the tracks have a lacking solder, hence more heat dispersal.


PCB thermal management procedures rely upon various elements including how much heat the parts and circuit disperse, the climate, the general plan, and the enclosure. Assuming the heat generated is low, the circuit can work without extra cooling. However, if the circuit creates higher measures of heat, there should be a cooling instrument to remove the heat.

To give thermally optimized PCBs, producers ought to consider all that impacts temperature right from the concept stage and all through the plan and assembling stages.


PCB Manufacturing Process Guide


The printed circuit boards form the main skeleton of most electronic devices. These are devices that have triggered major advancements in the area of electronics especially computational devices such as calculators, smartphones, computers, and other appliances. For clarity, a PCB routes electrical signals through electrical components to satisfy the required need or task. In simple words, the PCB directs electricity where to go hence ensuring that the electronics are brought to life.

To achieve these tasks, PCB has copper traces that form the substrate where the electrical signals flow from component to component. These copper routes will always determine the purpose of each PCB.

Before starting the process of printed circuit board design, the designers are advised to visit the nearest fab houses and explain the intended purpose of their designs face to face and also lay down their PCB manufacturing conditions and demands. This is very helpful as it will save the designers from making any errors that can originate from the design stage.

We are presenting this article in order for every designer to be conversant with the step-by-step PCB manufacturing process. Hopefully, most designers will come across this in order to understand how the design process is done and avoid most errors that may be witnessed during the process.

Steps for PCB manufacturing

1. The design and the output.

Printed circuit boards must be compatible with designs that have been created using the design tools. The most used PCB design tools include; Kicad, Proteus, EasyCAD, Orcad, and many others. Before beginning the design, the designer should contact the manufacturer to inquire about their favorite design tools so that to avoid making mistakes in the process.

  • After doing the design and it is approved for manufacturing, the designer will generate manufacturing files as per the designers’ specifications.
  • The most used file is the GERBER extension file which is also known as the IX274X

  • GERBER files carry around very important information like the copper tracking layers, the components notations, apertures, drill drawing, and many others.
  • At this point, all the design requirements are fine-tuned to ensure that they have been met.
  • After a close examination, the board is forwarded to the fab house for manufacturing.
  • To ensure that the design is fit for manufacturing, all the PCB fab houses run the Design For Manufacture (DFM) check before taking the circuit through the manufacturing process.

2. From file to Film

The PCB manufacturing will begin once the designer has generated the manufacturing files and the manufacturer has performed the DFM check.

  • The fab houses have a special type of printer called the plotter which is used for making the photo films of the printed circuit boards. These prints will be used to image the printed circuit boards.
  • Plotters, although they are laserjet printers, they are not standard laserjet printers.
  • They use highly precise technology to provide a detailed outcome of the PCB to be manufactured.

  • At the end of the printing, we must be able to come up with the result of a photo in black ink.
  • For the printed photo, the black ink represents the conductive copper traces and the other remaining clear part represents the non-conductive layers of the oriented circuit board.
  • The outer layer is different, clear represents the conductive copper layer and the clear indicates the parts that are to be etched away.
  • The plotter is used to generate this perfect film and the film is stored in a safe place to prevent contamination.

3. The inner layer printing: Where does the copper layers go?

The creation of the film in the above step is for mapping of the copper paths. In this step, we shall be print the figure of the film on the copper foil.

  • Here we are preparing to start making the actual PCB. Remember that the simplest form of PCB is made up of laminate board which has epoxy resin as the core material and the glass fiber which also is referred to as the substrate material.
  • The laminate is the receiving body of the copper that forms the substrate material.
  • The copper laminate material is first cleaned then passed through the decontaminate substance. During this stage, it is very important to ensure that no dust material settles on the substrate. The cleanliness of the PCB is very vital.
  • The availability of the dirt on the PCB might cause the circuit to have a short or open circuit.

  • Next, the cleaned substrate layer receives a photoresist which is a photo-sensitive layer that comprises a photoreactive layer that hardens moments it is exposed to UV rays.
  • The film is fitted into pins that hold them, into the laminate panel.
  • The film and the board are passed through a blast of ultraviolet rays. Light will pass through the clear parts of the film and harden the photoresist substance that is under it and on the copper.
  • The black ink that was printed by the plotter will always prevent the protected areas from hardening since these areas are slated for removal.
  • Then the board is washed with an alkaline substance to remove the photoresist material that was not hardened.
  • Then it is passed through pressure wash to remove anything that had not been washed by the alkaline and passed through the drier.
  • A technician examines the board physically to ensure that there is no error incurred during the process. He also ensures that all the resists present represents the copper that will remain during the final stage of the process.
  • This process is only suitable for boards with two or fewer layers. For multilayer PCB more steps are needed in the process.

4. Unwanted copper removal process.

During the process, there is a need to remove the unwanted copper material. This can be done by the use of a stronger material. here we shall be using the copper solvent solution to achieve our goal. As we do this, the wanted copper parts remain protected by the photoresist material.

  • Not all copper materials have a similar process. Some heavy copper PCBs require a lot of solvents to be etched.
  • Now that we have etched away from the unwanted copper material, the remaining copper material covered by the hardened resins needs to be cleaned. The hardened photoresistor needs to be washed away.
  • We shall end up with a glittering board with only the copper material suitable for the end product.

5. Optical inspection and layer alignment.

After cleaning all the layers, they require alignment punches to ensure that they are well aligned. The registration holes will align the inner layers to the outer ones. The technician will use the optical punch machine to align and punch the layers.

6. Layering up and bonding.

This is the stage where the circuit board takes shape. Al the separate layers are reunited here. With the layer accurate, ready, and confirmed, they only need to be joined together.

  • The outer layers are joined with the substrate.
  • This process is carried out in two processes that are the layering-up and bonding.
  • The outer layer is made up of fiberglass together with epoxy resin.
  • A thin copper foil covers the top and the bottom layers of the PCB substrate which contains the copper traces for conduction.

  • Bonding is done on a heavy steel table that has metal clamps.
  • The prepreg layer is the first one to be placed, then the substrate layer follows the prepreg layer before you finally place the copper sheet. Finally, the sheet of the prepreg sits over the copper layer.
  • Then this is prepared by pressing.
  • The entire operation is done automatically by bonding press computer.

7. Drilling

Holes are bored into the stack board. All the components that are planned to be fitted on the board are done so using the drilled holes. The drill holes will determine the accuracy of fixing these components.

  • The x-ray locator is used to locate where drill holes will be done.
  • Before the drilling operation is started, it is advisable you place a board of buffer below the board to ensure that the holes drilled maintain the high level of cleanliness.
  • A computer is used to control the drilling machine. The machine will use files received from the designer to locate the exact location of each hole to be drilled.

  • After drilling is complete, the entire holes undergo a cleaning process.

8. Plating and deposition of copper.

After drilling, the panel moves to the next stage which involves plating. In this stage, different plates are fused together using the method of chemical deposition.

  • After sparkling cleaning of the panel, it undergoes a series of chemical bathing where a thin film of chemical is deposited on the surface of the panel. The copper will go into the holes that had been recently drilled.
  • Computers are used to control the whole deposition process so that it can be as accurate as possible.

9. The imaging of the outer layer.

In step three, we imaged the panel with the photoresist. This process is repeated in this stage only that we only image the outer layer of the panel that has the PCB design.

  • The process starts with layers in a sterile room to prevent any contaminations on the surface of the PCB.
  • Thereafter we apply a layer of the photoresist on the surface of the panel. The prepped surface is then passed through the yellow room.
  • The ultraviolet rays affect the surface of the panel.
  • The goodness is that the yellow light UV rays do have not enough wavelength to affect the photoresist layer.
  • Hold the black ink transparencies together then blast the surface with UV rays to harden the photoresists.
  • The surface is then passed through a machine to remove the photoresist that was not hardened due to protection by the black ink.
  • Inspect the outer layer to ensure that it is in good condition as expected.

10. Plating

Here we are forced to go back to plating room like we had done in step 8 and do the electroplating of the plate with a thin layer of copper. In the process, the exposed section of the panel from the outer layer section we receive the electroplating of the copper.

  • Sometime the process mu involve tin plating so that we can be able to clean up the unremoved copper that remained during the etching process.
  • This tin will cover the amount of copper that is not to be etched away and etching will remove only the copper that is not tinned.

11. The final etching

As stated earlier, the tin will protect the wanted copper from etching. The unwanted copper foil and the copper below will be under the etching process.

  • The etching will be done using the method of chemical removal.
  • After this final etching to remove the copper material, we shall have a clear indication of the contacting and connecting copper paths remaining on the plate.

12. Application of the solder mask.

Before this process, the panel is cleaned nicely and covered with the epoxy solder ink before applying the solder mask on both sides.

  • Then the board is passed through a blast of ultraviolet rays which passes through the solder mask photo.
  • The covered portion will remain unhardened and will undergo removal to have a complete board.
  • Then the board will finally go via an oven to cure the soldering mask.

13. Surface finishing

Sometimes we would like our PCBs to have different abilities and this makes us electroplate our PC Bs with either gold or silver.

  • You will find some PCBs with hot air-leveled pads. This is done in this stage and it will always result in the uniform pad.
  • PCB manufacturing firms can generate different types of finishing depending on the customer and designers’ needs.

14. Silkscreen.

Almost all finished PCB will receive inkjet writing on its surface which will be used to indicate all the needed information about the PCB.

  • Then the PCB lastly passes through the final coating, plating, and the curing stage.

15. Electrical tests.

As the final precaution, the technician must perform electrical tests on the PCB to ensure that it is functioning as expected.

  • The automated system is used to do the electrical tests on the PCB and confirm its conformity with the design.

Machines and equipment used in the mounting of components in PCB manufacturing.

PCB drilling machine; even though we have said that the SMD is mounted on the surfaces, remember that there needs to be a connection between layers of the PCB boards. this is done via vias which are very tiny holes drilled on the board. This is done by the use of the drilling machine.

Wave soldering machine; this is used for the soldering process. It is also very important in the mass production of the boards.

The PCB brushing machine; we have talked about via drilling. Now after the drilling process is done, we have debris that is deposited. This debris is removed by the PCB brushing machine.

Pick and place machine; this picks the components, rotates them to the required direction, and places them on the PCB board in preparation for the components solder.
The PCB cleaning machine; does all the necessary cleaning that is required on the board. It also ensures that the board is very dry and free from any form of moisture.

Solder paste printing machine; this is for printing the solder paste to attach the components on the board. It ensures that the process is easy and first.

Reflow oven; this does the actual soldering of the boards.it ensures that the process is done in an effective way. We have three types that are currently common in the market; vapor phase oven, infrared oven, and convection oven.


Introduction to High Density Interconnects(HDI) PCB


In the current evolving PCB technology, there has been the introduction of innovative forms of PCB designs. One example is the HDI PCBs, otherwise called High-Density Interconnect PCBs. Assuming that you’re an individual from the business or a specialist, there is a need for you to equip yourself with the knowledge of this PCB variation.

The need to expand functionality and reduce package size has generally cooperated to drive the growth of HDI. Incorporating new parts to electronic items required extra components and circuitry components, however, demand in the market, whether for customer or business electronics, required more modest impressions and lower power usage (estimated as battery life). HDI began by sorting the issue of how to mount parts all the more proficiently.

In this article, we are going to take a look at what High-density Interconnect (HDI) are, their design, their benefits, their different applications, and their making process.


About (HDI) High-Density Interconnect PCB

  • High-Density Interconnector (HDI) is the state-of-the-art innovation for the development of printed circuit boards (PCBs). It utilizes micro via technology for PCBs with high wiring circulation density. As such, HDI PCB is a conservative board intended for items with more modest impression areas.
  • One significant advancement that made HDI conceivable is the micro via, a better approach for interfacing parts on a circuit board. Conventional PCB technology, from the last part of the 1940s through the 1980s, depended on photo-carved traces between parts, frequently utilizing mounting openings that went totally through the PCB for simplicity of assembling. Starting in the last part of the 1990s, the micro via circuit way with an altogether lower profundity to-diameter aspect ratio saw extreme testing for performance and unwavering quality.




There are roughly five unique variants of Via/Micro vias arrangements that can be utilized in HDI PCBs:

  • Stacked Vias: This type of PCB is infused with electroplated copper to interconnect high-density layers.


  • Stacked Micro vias: This is a micro via formed by stacking 1 or more micro via in a via that allows for 3 or more interconnection between conductive layers.

  • Staggered Vias: Formed when vias of different layers of PCBs are connected but not overlapping with each other.


  • Staggered Micro vias: A bunch of micro vias, framed on at least two distinct layers, which are balanced with the such that the land measurements are greater.
  • Via in Pad: Via in pad configuration is the act of putting a via into the metal part of a surface-mount footprint.


Benefits of High-Density Interconnect PCBs

HDI has many benefits as with it you can create compact small yet effective and powerful PCBs. Let’s dig into the beneficial aspects that come with HDI PCBs.

  1. Compactness

  • These PCBs are incredibly compact. Taking into account that HDI PCBs have a higher wiring capability, they are probably the most ideal choice for engineers searching for the littlest circuit board with high quality. HDI limit makes it more straightforward to transform a ten-layered PCB into a 4 or 5 layered one, which is incredible for those searching for more modest boards without diminishing quality.
  • Since most purchasers incline toward little gadgets, this can be a gigantic design advantage.
  1. Allows for the incorporation of more components

  • With High- density interconnects (HDI) PCBs, there is a higher capacity to put more electrical components on one side.
  • These HDI PCBs use blind and covered vias, and Via-in-Pad innovation, as strategies for setting parts nearer together, which brings about quicker signal transmission. Making it an ideal innovation for radio frequency (RF) circuits.
  1. Greater battery life.

  • HDI PCBs use less battery power when contrasted with customary ones. This is a direct result of cutting-edge production technology.
  • This innovation ties the electrical components coming about in the minimization of energy loss.
  • HDI circuits use vias rather than through openings that additionally lessen the power usage. This impact expands the life expectancy of your battery.
  1. Greater strength.

  • HDI PCBs are designed to utilize stacked vias, which accommodate more structural strength, in contrast with other PCBs.
  • This implies that they can be utilized in harsh conditions, in contrast with others, given the design’s intrinsic shielding and backing.
  1. Allows for better density transmission.

  • The high-density transmission in HDI PCB decreases impedance enlistment, works on signal integrity, and also has quicker routing abilities.


  1. Allows for higher transmission reliability.

  • If you are utilizing smaller BGA and QFP bundles in your plans and applications, HDI PCBs offer greater dependability in transmission when your PCB configuration cuts to the chase of large-scale production.
  • HDI PCBs can host thick BGA and QFP bundles than earlier versions of PCB technology.
  1. Allows for lower heat transfer.

  • Thermal transfer in HDI PCBs is diminished because heat will travel a lesser distance towards the vent from the point of their introduction to the vent for escape.
  1. Allows for management of conductivity.

  • Based on a particular board configuration, you can fill VIAs with non-conductive or conductive materials to make transmission easier between the parts.
  • You can likewise profit from better functionality since VIA-in-pad and blind VIAs let parts stay together. This prompts a diminished part-to-part transmission range, accordingly bringing about fewer intersection delays, lower transmission times, and greater signal strength.
  1. Allows for a smaller form factor.

  • If you are hoping to save space, you cannot do that better than the HDI board.
  • This is because an HDI PCB can decrease the number of required layers.
  • For example, if you are utilizing a customary through-hole PCB with eight layers, you can supplant it with an HDI utilizing a via-in-pad PCB with only four layers.
  • This implies that you will have a PCB that is small in size, containing VIAs that are essentially imperceptible.
  1. Laser-drill technology.

  • This innovation can change a PCB into a refined electronic circuit.
  • The laser-drill production style implies that small boards can now be utilized, providing the board with great heat resistance.

How High-Density interconnect PCBs are Made.

They are built out of various layers of conducting materials that are isolated by a dielectric material, which are stuck together by adhesive and connected by micro-vias.


HDI PCB Stack up

When manufacturing HDI PCBs, the following three approaches should be taken into consideration:

  1. Regular or standard lamination involving the use of vias /stratified thru-holes.
  2. Using plated through, covered, and blind vias for consecutive overlay/lamination.
  3. Using microvias for overlay development.
  • Various kinds of HDI stack-up. It is proposed in one of the standards (IPC-2315) that manufacturers use one from 6 different stack-up types for HDI PCBs. They are ordered from type one to type six. All things considered; the sort classified with IV turns into a decent choice for the HDI board due to a few ensuing issues. One of them is the assembling cost, which makes it an improper plan for mass production. Moreover, there are specific plan and assembly impediments in which the PCB merchants have not found a solution. Because of the plan and price impediments, in this section, we will just talk about HDI Stack types I, II, and III. What’s more here are the details of the 3 types.

HDI Stack up Type I

  • At the point when you take a look at the board structure, you will understand that there is a covered center or core with at least one micro via layer.
  • These multi-facets can be placed on both different sides, regardless of being conceivable on one side.
  • Even though the customary Type I doesn’t allow you to put covered vias, you are permitted to utilize blind and PTH vias.
  • Also considering the number of complete layers, you ought to look at continuing with fewer dielectrics (FR-4) most likely infer to delamination as a result of large temperatures. This will presumably be expected to exemplify a lead-free method of soldering.
  • Additionally, the proportion of length with opening width likely be significant for unwavering quality, likewise, you should continuously keep up with that proportion under 10 in the plated through-hole.

Image: HDI Stack-up type I.


  • The quality of HDI stack up Type I is a course of action of a buried core with 1 layer of micro vias, either on one of the sides of the different sides. HDI PCB stack up Type I most likely use blind vias and PTH vias, even though it isn’t covered vias.
  • 2 factors confine the layer measure of the shrouded core in HDI PCBs Type I:
  1. FR-4 dielectrics with exceptionally thin attributes can delaminate under high temperatures required for lead-free soldering.
  2. The ratio/proportion element or absolute of length to the opening width in the plated PTH through-hole via of must be smaller than ten for keeping sensible dependability.
  • Thusly, HDI stack up Type I won’t turn out to be astoundingly more ideal than the cover for high-thick boards which have different BGAs with pin-count.
  • This is because the via pads of PTH will expect to expand its aspect for greater counts of layers.
  • Furthermore, the use of micro via with a single layer won’t furnish fair benefits with the extraordinary aspects such as less thin traces and diameter vias.

HDI Stack up Type II

  • In stack up type II, you are expected to put at least one micro via layer along the edges.
  • Moreover, you are not expected to put them on both sides, but at least one is essential.
  • Manufacturers once in a while go through with staggering or stacking them.
  • It relies upon covered vias, and likely they stagger microvias from different ones.
  • The specialists analyze that this strategy is significantly more fitting for sheets with high-thickness spec, but you should recollect similar limitations similarly as with the HDI type I stack up technique.
  • Then, at that point, you simply have the option to put microvias in external layers, which prompts specific limitations for certain undertakings.

Image: HDI Stack up Type II

  • With one layer of micro vias, either on one of the sides or both of the sides, manufacturers likely fit certain micro vias in the middle of other microvias, then, at that point, store them close to buried vias.
  • Even though the HDI stack up Type II is strikingly better contrasting with the HDI Type I in high-thick boards using different fine-pitch parts, its limitations are comparable with the HDI stack up Type I for the part of the constraint in how much covered core layers.

HDI Stack up Type III

  • The basic distinction between HDI type II stack up and type III stack up is that in this methodology, you want to place at least two microvias layers in the sides and you are not expected to place them on both 2 sides.
  • Profoundly, this stack-up arrangement could be a decent choice for PCBs with high thickness with many layers and use different enormous BGAs with fine-pitch.
  • In the thin (FR-4) dielectrics as well as PTH openings, comparable requirements will exist.
  • The critical advantage of HDI type III stack up is that you can use the layers outside for ground and power planes. You can acquire that by putting microvias in inward layers, that is deliberately to ensure that the producers have sufficient layers to be used for routing of a signal.
  • At the point when you approve of the more costly expense, you likely use vias with stacks for astounding routing thickness.

Image: HDI type III stack up.

Designing High-Density Interconnect (HDI) PCB.

Common aspects to consider when designing HDI PCBs.

  • Before designing HDI PCB, we ought to consider a few common viewpoints into our HDI PCB design:
  1. Heat build-up: HDI regularly build-up heat and so you need to consider the thermal integrity of micro vias and trace widths in fast signal designs.
  2. EMI/EMC: All those radiation imperatives, for example, forestalling accidental radio wires and functional noise, especially as HDI is used for high-velocity signal plans.
  3. Impedance Control: You should oversee tight impedance (around ±10%) on dielectric layer density, spacings, and trace widths to ensure the impedance doesn’t impact the strength of the signal.
  • The want to factor heat, electromagnetic, and actual imperatives into an HDI PCB design affixes a ton of intricacy to the design cycle.
  • In any case, some EDA (Electronic Design Automation) programming devices have been created to diminish the complexity of tackling multi-layered PCB issues.

Tips for Designing High-density interconnect PCB Boards.

  • Planning PCB layout might be fairly mind-boggling in which the designers need to make hard determinations related to viewpoints to be considered as the main ones.
  • Then, at that point, the cycle turns out to be more complex when we design PCB for significant systems like automotive, clinical gadgets, military, or aviation, and systems with high-performance things like IoT and HDI PCBs.
  • Without considering the board design type, the top assembling outcomes are accomplished when the architect or designer joins the procedure of DFM that targets the benefits to the development of PCB. This is adjusted with the capability of their contract manufacturer (CM).
  • Design for Manufacturing (DFM) is an assortment of guidelines and rules which focus on a specific phase of manufacturing processes like a DFA (design for assembly) and DFT (design for testability). DFM likewise can be concerned about a specific kind of board configuration like HDI PCB boards.
  • Let’s discuss some crucial design tips which are pointed toward improving HDI PCB board fabrication.
  1. Sorting of vias to limit the complexity of the cycle or process.

  • The vias choice is a critical resolve that not only characterizes the assembling process required but also impacts the processing time and additional expenses.
  • The usage of buried or blind, micro vias, assists with decreasing material expenses and the number of layers.
  • However, the choice of if to use pad via, close vias in pad impacts the process intricacy.
  1. Give distance components or parts to limit tension and EMI

  • When a part’s position is with the objective that via positions are asymmetrically isolated, uneven strain can be epitomized in the board.
  • This can astoundingly impact throughput, how many sheets/boards are made.
  • Parasitic inductances, as well as capacitances from neighboring pins, presumably impact signal integrity.
  • Subsequently, it is proposed that displaying EMI to extract parasitics be included during the designing process.
  1. Select a small measure of components to employ HDI

  • The parts choice is generally critical; all things considered, the optimization of the choice of components is more significant for HDI PCB boards.
  • The components for your plan of the HDI PCB characterize trace areas, widths, sizes, and types for stack up and drill openings.
  • Execution capacity is a noticeable concern. Nonetheless, traceability, accessibility, and bundling ought to be considered too. Replacing components or overhauling the current design can help the additional material expenses and time.
  1. Tracing of the route to reduce issues of signal strength.

  • One illustration of the HDI benefits is the capacity to use more modest widths of the trace for the spread of the signal.
  • Reducing, widths of the traces should be intended to get the ideal signal integrity.
  • It incorporates using the most limited lengths of the traces, adequate digital and ground planes, steady impedances, power, and analog signal separation.


High-density PCB manufacturing process.

  1. The stack-up of the 1st HDI PCB.


The initial step of HDI fabricating requires a lamination process, like a customary PCB board. After overlay, laser drill out layer to sub out layer.

  1. Stack up of 2nd step HDI PCB.

The 2nd step of HDI production requires doubling of the lamination with blind buried openings. For instance, in assembling a six Layers HDI PCB there is a need to laminate L2 to L4 layer board, then laser drill L2-L3 or/and L4-L5, and finish different cycles.

  1. Stack up of 3rd step HDI PCB with buried via and blind via


The 3rd or 4th step of the HDI producing process is like the first or second step. The main contrast is that it requires more emphasis on the overlay cycle.

  1. Layer Connection of HDI PCB

In this sort of HDI PCB, there is a need for engineers to manage lamination stack up symmetrically. However, don’t demolish the original connection. What’s more its intricacy relies upon the original plan of PCB.


  • Going with a High-Density Interconnect PCB allows you the opportunity to take your mechanical game to an unrivaled norm. Not only are HDI PCBs practical, but also can bear large frequencies and are astounding for cell phones like tablets, PDAs, and workstations. You can make items that offer higher productivity and strength in smaller bundles, with practically no think twice about execution or plan.
  • Utilizing High-Density Interconnect PCBs will hoist your innovation to an entirely different level. These little PCBs are savvy, endure higher frequencies, and are incredible when utilized in our day-to-day gadgets. This is only a short prologue to this innovation, which is quickly turning into a good choice for electrical specialists. Need further developed data? Then, at that point, kindly feel free to our experts today to find out about this intriguing type of PCB innovation.


Introduction to Flexible Printed Circuit Board


It is an electrical circuit that connects electrical components with conductive copper wires to give mechanical support? It’s the foundation of many electronic projects, allowing for smaller, more compact, and less unpredictable designs.

Compare circuit boards installed in TVs in the 1990s to those available in modern LED designs and smartphones, and you’ll see how PCBs have grown over time into a more sophisticated circuit board.

Single-layer, double layer, multiple layer PCB boards, as well as rigid, flexible, rigid-flex, and aluminum circuit boards, are all varieties of PCB boards. Only flexible circuit boards will be discussed in this article.

Let’s get started.

A flexible circuit has a conductive layer of traces made out of copper wire.

Flexible PCB Manufacturing Process:

Flexible PCBs are made from polyimide as the base substrate material. Because this material is more expensive than FR-4, it must be utilized with caution. The nesting technique is used to keep circuit boards close to each other to make the most of the polyimide material.

Looping is One of the Steps in Making Flexible Boards.

The service loop guarantees that the servicing length and circuit assembly, which is the amount of extra material added beyond the designer’s limit, are both met.

Conductor Sizing

On the board, thin copper is used as a conductive substance. The circuit’s flexibility is due to the thin copper, which makes it appropriate for dynamic applications.


To compensate for any isotropic losses during the manufacturing process, the etching technique is performed. Copper foil thickness is half the line width loss in this technique. Conductor, etch mask, and the numerous types of conductors employed are all factors that influence line width.


Routing is straightforward. Routing reduces tension and makes bending and folding easier.

Planes that fly on the ground

Ground planes will help to lighten the load.

The use of ground planes reduces the board’s weight and improves circuit flexibility.

Before applying to fillet, you must first create holes to expand the pad area and split tension. Then, for dynamic flex circuit applications, add adhesive-backed films. Then, before applying photo imaginable liquid and film polymers that act as a solder mask and protect the circuits from both internal and external damage, apply screen-printable liquid overcoats.

Types of Flexible PCBs:

There are four different types of flexible printed circuit boards.

  1. Flexible Single-Layer PCB

As the name implies, a single-layer flexible PCB has only one conductive layer that rests on top of the flexible dielectric film. Only one side of the PCB is occupied by electric components.

Flexible Double-Layer PCB The conductive layer on both sides of the double-layer flexible PCB allows you to connect electrical components on either side of the conductive layer.

  1. Flexible PCB with Multiple Layers

Three or more conductive layers are separated by a dielectric substance on the multi-layer flexible PCB. The uneven lamination enables great board flexibility, and the bonding area often has a thinner lamination.

  1. PCB with Rigid-Flex

The rigid-flex PCB is a hybrid circuit board that combines stiff and flexible circuit boards to provide greater component density than standard circuit boards.

  1. Flexible PCB from HDI

High-density interconnects (HDI) is the abbreviation for high-density interconnect. Compared to other boards, these circuit designs are more efficient, dependable, and have better design, construction, and layout. Because of the thinner substrate material utilized in the fabrication of HDI flexible boards, they have higher electrical performance and smaller package sizes.


Flexible boards can be bent into any shape, which is why they are widely utilized for dynamic flexing and static applications in today’s world. Circuit boards for dynamic applications are designed for regular flexing, whereas circuit boards for static applications are designed for minimal flexing.

Flexible circuit designs are designed to endure extreme temperatures ranging from -200° C to 400° C, making them ideal for borehole measurements in the oil and gas industry.

Flexible circuit boards are useful in a variety of applications, but they cannot be used in place of rigid circuit boards. Because rigid boards are inexpensive and may be used in high-volume automated fabrication applications, they are widely used.

Flexible circuit boards are ideal for applications that demand increased performance, high accuracy, precision, and regular flexing. Applications of flexible circuit boards include:

  1. Cameras
  2. Antilock brakes
  3. Fuel pumps
  4. Ultrasound probes
  5. Semiconductor test
  6. Medical devices
  7. Motion systems
  8. Satellites
  9. Avionics
  10. Battery packs
  11. Manufacturing devices
  12. Airbag apparatus
  13. Bar code equipment

Circuits that are flexible or can flex are referred to as flex circuits. Flexible circuits are made up of a thin insulating polymer film glued to a substrate with a pattern of conductive traces. Flex circuits have been in use since World War II, and their applications are continuously expanding at a rapid pace.

Flex Circuit Sorts: There are many different types of flex circuits, and we’ll go through the most common ones here.

1: Flex on one side only: The most basic flex circuits are single-sided flex circuits, which have a single layer of metal traces on one side of a dielectric layer. Polyimide or polymer can be used as the dielectric. Insulation and protection from environmental degradation are provided via a polyimide overlay.


  1. Low cost to acquire.
  2. Minimized interconnect errors.
  3. Clean system appearance.
  4. Ability to reduce packaging size.


A double-sided flex circuit consists of numerous layers on both sides of a single dielectric layer. To build linkages between the two layers, metalized through-holes are plated.


Have small human errors compared to hand-built wire harnesses?

  1. The circuit boards can be mounted for all types of components.
  2. Have a small footprint which is highly applied in lightweight electronics due to its flexibility and elasticity.
  3. It is ideal for certain occasions i.e.
  • Has complex connections.
  • Hostile environments.
  • Power plane and ground operations.
  • Shielding applications.



Multi-Layer Flex: Multi-Layer flex circuits are made up of multiple copper layers separated by dielectric layers. Through holes join the metal layers once more. Layer design surface mounting has more complicated linkages.



Rigid-Flex Circuits: Rigid-flex circuits are made up of many circuit layers that are joined by an epoxy pre-preg bonding film, similar to a multi-layer flex circuit. Rigid circuit boards and flex circuits are essentially interchangeable in flex circuits. Component density is higher in rigid-flex circuits.



The Basic Materials Utilized in Flex Circuits: Now we’ll talk about the basic materials that are used in flex circuits.

  • Conductors: Conductors allow for the free movement of electrical electricity. Copper is the most frequent conductor, but other materials like aluminum, carbon, and silver ink are also utilized.
  • Adhesives: Surface mount component binding is done via adhesives. Adhesives are chosen based on the needs of the customer and the thickness of the conductor. Epoxy, acrylic, and PSAs are some of the adhesives that are employed (Pressure Sensitive Adhesives). Some circuits are constructed without the use of adhesives.
  • Insulators: Insulators are used to keep electrical conductors apart without conducting current. They can also be utilized as a source of support. Polyimide, polyester, solder mask, polyethylene naphthalene, and polyethylene terephthalate are all common insulators.
  • Finishes: Finishes are applied to metal surfaces to prevent oxidation. The final result is determined by how the circuit is used. Solder, tin, immersion in nickel or gold, silver, carbon, and other typical finishes are only a few examples.

Flex Circuits’ Advantages:

Flex circuits provide several advantages that make them more useful than standard cables and rigid boards.

  • Because the design is precise and the production is entirely automated, there is a significant reduction in assembly errors.
  • They require less work and have fewer manufacturing faults. There is also a reduction in the time and cost of assembly.
  • Flex circuits can be created in a variety of ways to accommodate a variety of complex layouts.
  • They are lighter hence take less room.
  • The flexible quality of the material also aids in reducing and absorbing the effects of any vibration.
  • They can be used in a variety of difficult situations. The thinner flex circuits also allow for more heat to pass through.
  • Mechanical connectors are used sparingly. There are also fewer connecting points, indicating that the system is more reliable.
  • Rigid circuit boards have fewer pieces and interconnections than flexible circuit boards. Complex arrangements with fewer interconnections can also be used to create rigid circuits.
  • Rigid-flex circuits have also been shown to be denser, with lighter components, allowing for more functionalities.
  • Flex Circuit Applications: There are two fundamental categories of flex circuit applications:
  • Static Application:
  • Dynamic Flexing Application: When the flex circuit is bent several times as part of the final product’s application, it’s called dynamic flexing.

Most of the electronics are made of flex circuits.

They’re utilized in automation, processing machines, and bar code scanners, among other things. Satellites and GPS systems use them as well. Flex circuits have an almost limitless number of uses.


PCBgogo is a company that specializes in producing high-quality PCBs (Printed Circuit Boards) at a low cost. These boards are made in order to meet your specific requirements.

Data communication, optical networking, medicinal treatment, industrial control, aerospace/military, and so on are only a few of these sectors.

The flexible circuit board is meant to save space and increase flexibility to satisfy a smaller and greater density mounting design. In a nutshell, FPC is the only way to assure that electrical items can be miniaturized and moved.

The flexible printed circuit is either an etched copper circuit with a polymer substrate or a polymer thick film circuit. Solutions range from a single conductive line to a complicated layered 3D package for both thin and light, compact structure, and complex electronics. Flexible packages have lower overall quality and volume than standard wire harnesses by 70%. Reinforcement can also improve the flexibility of a flexible circuit.

Different contours and special packaging sizes are allowed on the flexible PCB, which may be moved, bent, and torsion without damaging the conductor. The volume is the only constraint. A flexible circuit can be used in the periodic motion of the internal connection system and become part of the end product’s function since it can endure millions of dynamic bending. Flexible circuits benefit products that require electrical signal/power transfer and have a modest shape coefficient/package size.

The electric performance of flexible circuit boards is good. Low dielectric constant allows for electrical signal transmission; superior thermal properties allow for simpler cooling of components, and a higher glass transition temperature or melting point allows components to operate at high temperatures.

Flex circuits can give improved assembly reliability and output due to reduced hardware for internal connections, such as common solder points used for standard electronic packages, trunk lines, bottom lines, and cables. While assembling, higher component dislocation appeared to be easier. Because standard linking hardware is made up of numerous complex systems. With quality engineering, a thin flexible system is intended for only one-way assembly, eliminating human error associated with standard and independent routing activities.

To put it briefly,

  • Flexing for easier installation and repair • Reduced weight and space • Dynamic flexing requirements
  • Improve repeatability and dependability
  • Controlling the temperature
  • Enhance the appearance
  • Dismantle all the connections
  • Ensure that high-speed circuitry has consistent electrical characteristics.
  • Lower the cost of assembly
  • 7 Tips for Creating a High-Quality PCB

The seven important points that an EE or a newbie should remember if they want to create high-quality PCBs for their electronic applications are listed below.

  1. Material to make the board: In any of the PCB designs, this is the first step to start with. You need to know the resources for making a PCB.
  • A printed circuit board (PCB) is made out of a non-conductive and solid material that has been laminated with copper. Copper plating aids in the creation of a conductive surface. The foundation material is commonly FR-4, which is a glass-reinforced epoxy. This material is both cost-effective and flame-resistant.
  • PTFE or ceramic bases: combined with various fillers are employed in RF or high-performance circuits.
  1. PCB stack-up: The number of layers on each PCB is referred to as the PCB stack-up. It enables an EE to comprehend each layer’s required impedance. Appropriate layer count estimation allows the engineer to choose the best fabrication procedure to achieve the desired yield, reliability, and production cost savings.
  1. Copper Traces: The copper traces on a PCB are the most crucial components. While designing them, it is critical to grasp their properties as well as their limitations. Copper traces are commonly made by extracting copper from a solid metal sheet that has been laid on top of the base material.
  2. VIAs: are small drilled hole that goes through two or more adjacent layers, the hole is plated with copper that forms an electrical connection through the insulation that separates the copper layers.

The types of VIAs include: Buried, Through, Blind and Micro.

  1. Selection of parts: It is the most tiresome step in any PCB design work. Choosing the right part will help to minimize the number of errors and ensure the high quality of the designed PCB. For you to produce the best PCB in the market, you need to keep the following in mind:
  • Selection of the widely used part which is readily available and is no more in the market.
  • Some of the parts are sold in large numbers you have to be aware of when selecting them for use.
  • All elements are offered in a package that is attached to the PCBs. Some of the parts are available in a number of packages which may make them compatible.
  • Some parts are sold in bulk, so keep that in mind while choosing them for your project.
  • All components come in a package that makes it easier for us to attach them to the PCB. Some parts are available in various packages, making them potentially interchangeable.
  1. Design Guidelines: An EE should focus on the design rules after addressing all of the preceding requirements. Cross-talk budgets, component placements, layer allocations, time of flight analysis, Design for Manufacture (DFM) standards, and other factors should all be taken into account.
  2. Signal and Power Integrity: This is one of the positive elements of a solid PCB. Signal fall and rise times, drive strength, track lengths, and characteristic impedance are all things to think about. Signal-integrity (SI) simulations will be run before and after the layout to guarantee that the quality is maintained.

Large currents are required for high-performance electronic circuits. As a result, the power distribution network’s AC and DC performance should be evaluated.

The preceding list is a nice place to start for both seasoned and inexperienced EEs. We’ll go over some of these aspects in more detail in future blogs, as well as walk you through various PCB assembly jobs.

Fabrication of Circuit Boards

Jumping right into fabrication without understanding the relationships and procedures between the schematic or idea you have in mind and getting that idea manufactured might not be a good idea. It may be helpful to define a few other words and their interrelationships before defining PCB manufacture.

  • Development of PCBs: The process of moving a circuit board design from concept to production is known as PCB development. There are usually three stages to this: design, manufacture, and testing. And, except for the simplest designs, this approach is iterative, intending to achieve the greatest quality design in the time allocated for development
  • PCB Manufacturing: The building of your board design is known as PCB manufacturing. This is a two-step process that starts with the manufacture of the board and finishes with the assembling of the printed circuit board (PCBA).
  • PCB Testing: Following manufacturing, PCB testing, also known as bringing up, is the third stage of PCB development. During development, testing is carried out to assess the board’s capacity to perform its planned operating functions. Any mistakes or locations where the design should be adjusted to increase performance are detected during this step, and a new cycle is started to include the design changes.
  • PCB Assembly: PCB assembly, also known as PCBA, is the second step or stage of PCB manufacture, during which the board components are soldered to the bare board.


PCB Development Stages

Advantages and downsides of PCBs

(PCB) Printed Circuit Board. This circuit board is an essential component of modern electrical devices. A printed circuit board should contain a certain number of active and passive parts. Traces/ findings on the board connect the component from one side to another. With the advent of very small-sized electronic components, it is entirely possible to create very massive circuits on small printed circuit boards.

To know more about the printed circuit board, the following are the benefits and drawbacks.

PCB Drawbacks include:

  1. Uneven PCB surface finishes.
  2. It is not a good choice for fine-pitch.
  3. It’s made of lead.
  4. Once injured, it is difficult to repair.
  5. It can be applied in a certain circuit.
  6. Once printed, we can’t be changed.
  7. Reduced or plugged in
  8. One sort of circuit operation necessitates reworking.
  9. Harmful chemicals are produced during the etching process, which pollutes the environment.

Advantages of PCBs:

  1. PCBs are inexpensive, allowing for mass production at a cheaper cost.
  2. Changes can be made.
  3. The product is found all over
  4. Shelf life is excellent.
  5. Smaller in size and less wire is used


The flexible PCB designs are reliable as they come with few solder joints and contact crimps. The circuit requires less space due to its flexibility.


Types of Printed Circuit Boards


In the world of electronics, printed circuit boards have revolutionized the way systems function. They have impacted a lot of things in terms of smartness and efficiency where electronic systems are imaginatively thinking like humans. The printed circuit board area has also experienced significant growth that has led to the development of different types of boards depending on the function intended, the technology used, the needs of the consumers, and the application area of interest. The material used in the designing of the PCBs has also contributed to the raising of different types of these PCBs. Designers and engineers have the task of choosing the appropriate type of PCB to consider depending on the client’s specifications. There are no ready-made PCBs and hence it is the duty of the designers to customize them according to need.

The various types of PCBs available in the market and PCB fab house are:

  • Single-layer PCB
  • Double-layer PCB
  • Multi-layer PCB
  • Rigid PCB
  • Flexible PCB
  • Flex-rigid PCB
  • High-Density Interconnect PCB
  • Blank PCB
  • Custom PCB
  • High-frequency PCB
  • Aluminum backed PCB

Let us have a deeper discussion about these types of PCB below.

Single-Layer PCB

This is the most common type of PCB that is available in the market currently. In this type, all components are located on one side of the substrate while the circuit is on the other side. The board has one conductive layer hence acquiring the name single-sided PCB.

  • It is the simplest form of the manufactured PCB with only one layer of material of conduction.
  • They are best suitable for low-density production.
  • The holes where the components are attached are not platted through.

Advantages of single-layered PCB

  • It is cost-effective. For instance, if you do not need to waste the extra space that comes in with the double-sided PCBs, then this is the best type you need.
  • Suitable for low-density project designs.
  • They can be easily manufactured because components can be inserted in the easiest way possible.
  • They are very easy to design as compared to other types of PCBs and you have a lower probability of making mistakes in the process. Also, since is made up of a single layer, drilling and soldering can be done very easily.
  • They can be repaired easily in case something goes wrong.

Uses of Single-layer PCB

  • Used in-home equipment and appliances such as milk vending machines.
  • Electronics such as printers, mobile phones, cameras, calculators, and radios.

Double-Layer PCB

From research, this type of PCB is considered the most popular in the industry. They are the getaway to more advanced technologies that exist in the world.

  • As the name suggests, they have a thin film of the conducting copper material being spread on both sides of the PCB, that is the bottom and the top side.
  • Holes are drilled through the board to allow the connection of the circuit on one side of the board to the circuit on the other side of the board.
  • On the double-layered PCB, components are connected by the utilization of two methods namely the through-hole technology and the surface mount technology.

Through-hole technology as the name suggests involves connecting components into the board by inserting their leads in holes and soldering the respective components leads.

For the surface mount technology, the components are placed on the surface of the board and connected by the use of the pads instead of the leads. Sometimes the terminals of these components are made up of many small pins or leads.

  • Surface mount technology is the best as it allows the board to save on space hence making a single small board complete more functions as compared to the through-hole technology.

Advantages of the Double-Sided PCBs

  • This type of PCB offers increased compactness in circuits.
  • It is relatively cost-effective
  • It is more flexible to designs hence a more ideal option for the design manufacturers.
  • It offers a transitional level of circuit density.
  • Reduced cost due to compact board.
  • They have reduced sizes as compared to the single-sided PCB.

Uses of the Double-Sided PCBs

  • Used medical devices such as scanners and x-rays.
  • Mechanical systems such as the high current battery chargers and the engine controllers.
  • Find use in the lighting industry because of the advantage of having two insulating layers.
  • Automotive and aerospace industry because this type of board can withstand high-frequency vibrations.

Multi-Layer PCB

This is a PCB that contains three or more conductive layers and its through-holes are plated. The multilayer PCB comes with different models.

  • If the multilayer PCB is constructed using both rigid and flexible material the PCB is referred to as rigid-flex printed circuit boards. this board can be bent into any given shape.
  • In multilayer PCB, the copper conductive layers are bonded together with resin layers.
  • This is the most complex type of printed circuit board available in the field of electronics.
  • Due to this complexity, you will realize that this type of PCB comes at a relatively high cost.

Application of Multi-Layered PCBs

Medical devices Applications

Electronic devices are very vital in the area of medical diagnosis and evaluation. Like any other area of specialization, the medical field is adapting the technology of miniaturization. With the adoption of non-invasive treatment, many areas in the field of medicine have adapted the miniaturized technology.

  • Multilayer PCBs have solved the need for these smaller devices due to their lightweight and small in size shapes.
  • Examples of medical equipment using multilayer PCB include x-rays, CT scans, MRI, and blood pressure equipment.

Consumer Electronics Applications

Consumer electronics cover a wide range of electronic equipment that is used at home. This includes the devices that are used for communication such as smartphones and laptops.

  • They also include entertainment systems such as music players, TVs, and the kitchen appliances such as microwaves and electric kettles.

Most of the devices listed above are fitted with multilayer circuit boards because such type of PCBs contributes to their better performance and compact designs.

Industrial Electronics

Electronics equipment in an industrial setup is quite different from consumer equipment. This is simply because such electronics are exposed to harsh environmental conditions such as high temperatures, vibrations, noise, and dust.

  • Examples of industrial equipment include high-speed assembly lines, spray painting robots, automated assembly lines, and packaging conveyor belts.
  • These systems are designed for a long time functioning such as working throughout the day.

In this case, a multilayer PCB is required due to its durability and compatibility.

Computer and Devices

In the modern world. It is almost impossible to imagine life without computers which come in hand with automation. Most parts of these computers from motherboards, the mouse, and the CPU use the multilayer PCB to achieve its relevance. This is because the multilayer PCB has the advantage of space-saving as compared to others. This type of PCB can achieve superior performance when you compare it with other types of PCBs.

Telecommunication Electronics.

  • In the area of telecommunication, multilayer PCBs find use in many devices such as satellites and GPS systems which require durability as they still maintain high-performance functionality.
  • The development of wireless devices has triggered a high demand for high-speed data transmission and miniature devices which can only be achieved through the use of multilayer PCBs.
  • Other applications of these PCBs in the area of telecommunications include; alternators, tower and radar communication, attenuation, amplification, and many others.

Aerospace, military, and defense.

Similar to the area of telecommunication, military and aerospace areas require high-performing and miniature PCBs and this can only be offered by the utilization of the multilayer type of PCBs. These PCBs offer high-speed which is required in the field of the military.

Rigid PCB


This is the earliest and most traditional form of the printed circuit board in the world. This type of PCB remains popular. They are rigid and inflexible and therefore, they cannot be bent or coiled.

  • They are made up of layers such as substrate layer, solder mask layer, copper conducting layer, and silkscreen layer which are permanently fixed with adhesive and high temperature.
  • Although some of these circuits are single-sided PCB, most of them are either double-sided or multilayered.

Advantages of Rigid PCBs

Compact PCBs

One of the very significant things about rigid PCBs is that they are small in size. The compact size of the PCB ensures that various complex circuits can be created.

  • It takes up limited space in its area of application.
  • Due to the reduction in the size of the PCBs and their components, this type of PCB provides a basis where this can be achieved.

Low Electronic Noise

The design of this PCB ensures that we have very minimal electronic noise. This can be achieved by ensuring that the assembled electrical circuit components have minimal current flowing between them.

The effect of this is low radiation effects from the PCB.

The low radiation current and electric flow mean that the PCB is not able to pick many electromagnet waves hence reducing cross-talking between electronic components.

Ease in repair and diagnosis.

These types of PCBs are easy to repair and also diagnose in case of any mechanical challenge.

  • All the components in this PCB are marked hence making it easy to locate any component hence making the process of assembly and disassembly very easy.
  • Also, the traces of this type of PCB are well marked and visible making it easy for the technician to follow them during the repair.

Immunity to movement

The components are fixed to the board using the solder and the flux. The process is done such that the components remain fixed on the board and they cannot move even if the PCB is used in areas with has conditions such as high temperatures and mechanical vibrations. This makes such PCBs suitable for applications that involve shaking and frequent movement.

Flexible PCB

  • Unlike the rigid PCBs that are made up of rigid materials like fiberglass, flexible PCBs are made up of flexible materials that can be bent or flex and move such as flexible polymers.
  • They come either single, double, or multilayered types.
  • Since they are printed on flexible material, then this type of PCBs will cost relatively higher as compared to others.

Features of flexible PCBs and Rigid PCB

Advantages of flexible PCBs

  • This can be freely bent, wound, and also folded. This allows it to be moved in any space whether tight, small, or shapeless.
  • They can greatly reduce the weight and the size of the printed circuit boards.
  • They have the benefit of good solderability and good heat dissipation.

Flex-Rigid PCB

This is a combination of both the rigid PCBs and the flex PCBs. It is made up of a multilayered printed circuit board that is combined with some layers of rigid PCBs.

Advantages of flex-rigid PCBs

  1. Increased reliability.
  2. Space-saving
  3. Reduced cost
  4. Ease of testing

High-Density Interconnect PCB

PCBs are made up of components that are interconnected and fixed on them. The components are connected by wiring them on the board. The wiring is in form of tracks and traces. Some boards involve a small low density of wiring capacity per unit area while others involve very high-density wiring capacity per unit area. HID which is an abbreviation of the high density connect boards are boards that have a high density of the wiring capacity per the unit area when you compare with the normal PCBs.

  • These boards are very special as they come with finer lines, tiny vias and a high connection density of the pads than the one that is utilized in the normal boards.
  • A good HID PCB should have one or all of the following:

  1. Blind and buried vias
  2. Micro vias
  3. Build-up lamination
  4. Considerations of high signal performance.
  • The HID boards are very compact with small vias, micro-vias, spaces, pads, and copper traces.

Benefits of the HBI printed circuit boards.

This technology has found great importance in smartphone and tablet manufacturing. Apart from that, they have become of great use in laptops and desktop computers. The following id the great benefits of the HDI PCBs;

  1. Tighter designs; when we have a look at the high density interconnect PCB, we will realize that the board has a very high-intensity nature of circuit network connection. This high intensity implies that the board takes literally less physical space. The utilization of design features such as blind and buried vias enables the designers to come up with more compact builds and this will make the HDI circuits very versatile.
  2. Reliability; the connectivity that is employed in the design of the HDI boards such as the use of the blind vias and the buried vias makes them more physically reliable. This is because such types of connections are less likely to get compromised.
  3. Lighter material; the material used is very light and cooler. The traditional and other PCBs use a different variety of materials but the common one is the combination of copper, aluminum, fiberglass, and other metals which might prove to be bulk. This is not the case with the HDI boards.
  4. Sharper signals; since these types of PCB has more compact systems, then the outcome is that the signals will have a very short distance to travel hence avoiding many disturbances that come in with the long-distance travel. This advantage makes the signal rich their destination undisturbed hence sharper performance of the board.
  5. Pocket friendly; four layers of the HDI boards are enough to perform all the functions of the standard PCB layer. The board has reduced size, which implies a reduction in the cost too.
  6. Low power consumption; these types of boards have a high number of transistors and also signals travel a very short distance. These features play a greater role in reduced power consumption in these types of boards.

The common use of the HDI boards.

These types of boards have found many areas of use in the modern world of technology. Let us have a look at a few areas where the high-density interconnect boards are used;


Due to the smaller size of the HDI boars, medical designers have found great interest in this type of board. The medical equipment is compatible with HDI because they are very small and can fit into them for example in implants and also in the imaging equipment. The equipment plays a very significant role in the treatment of the ailments and therefore smaller chips that require less intervention have to be used. Let us take an example of a heart pacemaker that is implanted in the heart to regulate the speed of the heart bit. The pacemaker should be very tiny and therefore the HDI has provided boards that can solve the size of the pacemaker issue. another good example is the colonoscopy which is passed through the colon of a human to carry out the colon examination. It is evident through research that so many people avoid the colonoscopy examination due to the painful experience but the availability of the HDI technology has drastically reduced the size of the camera and improved the visual quality of the same camera which has made the colonoscopy process less painful hence triggering the increased number of people searching for the service.

Aerospace and military.

Military use strategic equipment such as missiles and some other defense communication devices. This equipment utilizes the HDI technology in their boards since it is the only efficient available method. there have been greater changes in aerospace technology and HDI has always provided the needed solution. Communication devices such as wireless phones and trackers are becoming very tiny in size and this is due to the involvement of too many tiny layers of the HDI boards.

Automotive industry.

The car and other automotive manufacturers are falling in love with the HDI boards simply because with this type of board you are assured of greater discoveries and innovations. This board allows the saving of more space in the vehicle and also have increased performance of the same vehicle. To be specific, Tesla uses the HDI technology to run the electric car system where it helps in extending the battery life of the system. Other driver assistants such as cameras, tablets etc fit on the dashboard.

Digital devices.

Let us make a comparison of todays digital devices like the smartphone with what we had 10 years ago and you will make note that there is a very big improvement in size, thickness and weight. This has been made possible by the use of the HDI boards in this area. Thinner and more compatible smartwatches are also a product of the HDI boards.

Advantages of the HBI PCBs

  • Compact design; the strategic use of the burred and blind micro vias makes the board compact and this leads to spacing.
  • High reliability; the preferred use of the stacked vias makes the board have a super shield against harsh environmental conditions.
  • Phenomenal versatility; this board is ideal where weight, size, and performance are of great consideration.
  • Cost-effective; the functionality of a 6- layer standard PCB can be reduced to a 4-layer HDI board without altering its intended purpose.
  • Better signal integrity; vias and pads and blind technology are what is mostly used in the HDI. It also has very short compact trucks or traces and this reduces the chance of the signals being interfered by the external forces hence achieving of very high signal integrity.

Other types of PCBs include:

  • Blank PCB
  • Custom PCB
  • High-frequency PCB
  • Aluminium backed PCB