[PostWidget1]

The process of PCB ordering and manufacturing is time-consuming and requires prior planning. This tells us that it is not necessary to order for less volume PCBs through a manufacturer or even order for your own hobby PCB. To make the process economical, we have to understand how to make our own boards from home. This tutorial is about how to make our own PCBs from home to avoid some expenses and also saves time in the end. it is very significant to note that this process cannot be used to build complex circuits and sometimes it is very unreliable. Therefore, the process is important in the building of simple circuits such as the Arduino circuit that we shall be using in this process.

Homemade PCBs Types

Generally, there exist two methods of manufacturing PCBs at home:

1. The ultraviolet rays method.
2. The toner transfer method. (most commonly used)

• These two methods are almost similar with only one or two steps making the difference.

1. The Ultraviolet Rays Method

 

The following steps will show you how to do your own PCB using ultraviolet rays.

The material needed for this method to be accomplished practically are listed below:

PCB Comopnents:

• Transparencies
• UV pre- sensitized Copper Clad Boards
• Brother HL-2070N Laser printer
• 200 UV LEDs
• 200 Resistors of 470 ohms.
• Breadboards
• Chest/box to house
• Transparent plastic picture frame

Chemicals:

• Photoresist Developer
• Muriatic Acid
• Baking Soda
• Acetone
• Hydrogen Peroxide

Tools:

• Soldering
• Screwdriver
• 26 and 16 gauge wire
• Wire stripper
• Gloves
• Goggles
• Power Supply
• Q-Tips
• Buckets for chemicals
• Timer

Step one: Building of the UV LED Box.

 

We started by finding a box that is one foot in height. Then we place the breadboards on the transparent glass paper and do the arrangement of the LEDs as shown in the image above.

Step two: Drawing of the Schematic

The next step involves drawing the schematic for the circuit that you intend to design.

• There is so much free Electronic Automation Design software available in the market and you have to choose the one that you are conversant with. For me, I had to settle for Autodesk Eagle.
• Once the schematic and the layout has been finished, you have to print it on the transparency.
• For you to be able to print only the desired layers, turn on the top layer, the vias, and the pads. This is achieved by selecting the correct setting in the EDA software.
• The end results of the schematic and printing should be similar to what is displayed in the image below:

 

Step three: Exposing the Pre-Sensitized board to UV rays

 

• Place the printed transparency about 10 inches above the LEDs. Let the inked face upwards the sky.
• Ensure that the room is dark then peel off the white film on the pre-sensitized circuit board in order to expose the photoresist.
• Place the printed circuit board on the top of the transparency while the photoresist is facing downwards in the direction of the LEDs.
• Place some weight on top of the printed circuit board to ensure that the photoresist is tightly fitted on the ink of the transparency.
• Turn on the UV ray box for at least one minute.

Step four: The Developer Solution Preparation.

 

• The next step is the preparation of the developer solution where one part developer is mixed with 10 parts of water that are the ¼ cup of the developer is equal to 2 ¼ cups of the tap water.
• Ensure that you mix the developer and water completely so that the photoresistor can be eaten uniformly to get the desired end product.
• Place the PCB on the solution and shake it up nicely to wash away the parts that were exposed to UV rays. This will take at most 10 seconds.
• Do not leave this board on the developer for a long time since by doing so, the developer might wash away all the photoresists.
• Now place the PCB in cold water to stop further reaction once you remove it from the developer.
• Don’t spill of the developer solution for it can be reused for other boards development.

 

Step five: Etching Copper Away.

 

• Here we start by preparation of the solution where one-part muriatic acid is mixed with two parts of hydrogen peroxide. In my project, I made use of 8oz. of muriatic acid against 16oz. of hydrogen peroxide.
• This acid is stronger than the photoresist and therefore, you must be very careful. Ensure you make use of the proper personal protective equipment before making use of the product.
• Put the printed circuit board into the solution and ensure that you shake the bucket very carefully.
• You will notice the solution turning into green color as copper is being etched away.
• As soon as you notice that the whole copper has been etched away, remove the PCB from the solution. The time frame for copper to be etched away is about 2 minutes.
• Use a hose to clean the etched PCB.

 

Step six: Removing of the Photoresist.

• This step makes use of the acetone and Q-tip to remove the photoresist.
• It is very easy to remove the photoresist using Q-tip that has been dipped in acetone.
• Keep using new Q-tips until they remain white to indicate that the whole photoresist has been removed.

 

Step seven: Populate the Printed Circuit Board with Parts

 

 

At this point with you is the PCB to populate with all the parts that are required. Enjoy the process.

The Toner Transfer Method

According to me, this is the simplest method to do your own PCB at home as compared to the ultraviolet method we have discussed above. This method offers advantages such as stability and reliability

• We are going to have a look at how this method is made possible and let us start by listing the material that we require in the process:

 

Materials

• Cello tape
• Acid bowl or Acid Chamber
• Cup
• Hand Gloves or Safety Gloves
• The printed layout on A4 Glossy Photo Paper
• Scissor
• Sandpaper
• Hacksaw
• Permanent Marker pen
• Copper Coated Board
• Steel Wool
• Muriatic Acid
• Hydrogen Peroxide

Step 1: Making your Customized PCB Design

Here we shall be masking the use of the EDA design software to generate our schematic and the layout.

• If you are new to PCB design you can search online for several tutorials on how to do design using EDA software.
• Again, there is too many design software that you can choose from such as fritzing, Kicad, Proteus, EasyCAD, and many more.
• On the EAD you will be able to generate drawing like the one shown below:

Step 2: Printing of the PCB Layout

You must print your PCB design on a good laser printer because we shall be utilizing the toner transfer method to do the transfer of the copper surface by use of the heat and copper coated board as the substrate.

• Check out the image that is attached below:

• Use thin and glossy photo paper for image printing because the normal paper will absorb the color immediately you print.
• Make sure you use the thick black color because there is no other color that works out.
• Check the printer settings attached below:

Step 3: Preparation of the Single-sided Copper Board.

After the designing and the printing has been done, now we look forward to the preparation of the copper board.

• Here the quality of the single-side coated copper board is very important. You should settle for the best quality otherwise you might end up with poor results.

• Clean the copper surface by scrabbing to remove the dust and any other unwanted material and the copper oxide materials which could have been formed through oxidation. You can utilize steel wool or sandpaper in the process of cleaning.
• Make sure you don’t use the sandpaper and the steel wool hardly. Use them gently to get a nice surface.

 

• Generally, you will get the copper board in a full standard size, and hence you have to utilize the hacksaw to cut the required size.

• Now, cut your printed PCB design using the laser printer. Use the razer to cut the part printed and place the printed side on top of the copper board and fix the sides on the board using the tape so that it cannot move during ironing.

Step 4: Transfer the ink to the board by ironing.

• As I had said earlier, this is the toner transfer method. we will employ heating and pressure techniques to transfer the ink from the paper to the copper board. We shall utilize a hot iron to do so.
• Use simple and gentle ironing on the backside of the copper so that the heat can be transferred easily.
• Iron for like 15 minutes and you will see the copper turning blackish after ironing for like 10 minutes. This will be the indication that toner has been passed well.

Step 5: Paper Removal from the Board

• Drop the board in hot water for about 15minutes to allow it to soak. After 15 minutes the paper will have softened.
• Now, rub it with your fingers and remove it gently then peel off the layers one by one.
• After the first layer peeling off, then drop it in the water and repeat the procedure to peel of the second layer.
• Repeat the procedure until you peel off all the paper layers from the board.

• When you have removed all the paper layers, the copper surface gets dry but we still have a paper layer sticking on the surface of the board which cannot n]be removed by hands.
• Take a toothbrush and gently brush it off as shown below. You will realize that with brushing the thin copper paper gets off.

Step 6: Acid Solution Preparation for Etching of the Copper Layer.

• This step involves the making of an acid solution that can be used in the etching of the printed copper-coated board.
• Ferric chloride is normally used in the making of the acid. But, in our process, we shall be using another method because ferric acid is not easily found and if the ferric acid is available the purchase procedure is very tiring due to the documentation that is required.
• Therefore, I shall be using muriatic acid which is readily available. I mixed 3 cups of muriatic acid with 1 cup of hydrogen peroxide in a bowl to make a solution that is green in color.

Step 7: PCB Etching

• Now that the acid solution is ready, just drop the PCB in the solution and leave it for 15 minutes to etch.
• For complete etching ensure that after every interval of 2 to 3 minutes you steer the solution.
• After complete etching, you need to rinse the final product with clean water to stop further etching.
• After the board has dried, take a piece of cotton and drop it on acetone solution and cleanse the board until all the greenish color have been removed.

Step 8: Drill holes for Mounting your Components

After all the above procedures, we have to end up fitting the components on the board. To do this, we should be available to drill holes on the PCB.

• Holes can be drilled using a drill either homemade or commercially available PCB drilling drills.
• For me I used my own homemade drill shown below:

Advantages of Doing the PCB by yourself

• The process saves time that could be have been consumed while doing the booking of the manufacturing process. The PCB can be manufactured quickly and a complete PCB be obtained within the shortest time possible.
• It is cheaper for low volume production of PCBs.
• It is the best method that is recommended for low-volume prototyping.

 

The Disadvantages of doing PCB by Yourself at Home.

• Mass production cannot be achieved by the use of this manufacturing process.
• The manufacturing process is cumbersome to the user of the process.
• If high efficiency and accuracy are required, this method cannot be utilized because it has very low efficiency.
• High quality cannot be guaranteed while using this method.
• Finding the material for this process is not for average people.
• Finally, if the design is so complex, you cannot find the solution for this board and therefore you will be forced to look for a manufacturer to help you out.

 

PCB Designing Process for Mass Production

After having a look at the homemade PCB process, here am going to give you a precise way of doing PCB manufacturing for mass production. It will be a step-by-step guide that will be understandable for anybody who has the ambition of understanding this process.

Step 1: Schematic Design

The schematic design also known as the schematic diagram is the blueprint for any PCB design process.

• It is a representation of the logical component connections, the traces, and the circuitry that is required in the process of the PCB design.
• Every component that is to be used in the design has a symbol that is placed on the board to represent the component.
• It is the work of the client to come up with the idea of what should go into the PCB as the designer will build the schematic depending on the idea.
• Each symbol used has one or more pins that are connected by lines to form nets.
• The schematic is made using the EDA software as discussed in the homemade PCB design.

Step 2: PCB layout planning.

Once all the symbols have been laid on the circuitry to form the schematic, the board is taken through the next stage called PCB layout which involves the following procedure:

• Creation of all the models of the physical components within the tools.
• Make sure that the nets don’t come in contact with each other hence avoiding sort circuits once the PCB is built.
• Setting up the physical appearance of the PCB. The shape and the color will be preferred.

Step 3: Placement of Components Planning.

Once the design of the schematic is ready, the next process involves the placement of the components planning. This process is very helpful in determining how many PCB layers you will require and many other specifications in your design. These steps will also ensure that you avoid errors in the process of design hence saving time and drastically reducing the cost of your PCB manufacturing.

The footprints are placed in the following order:

• Fixed components like the switches and the connectors are the first to be placed in the layout datasheet.
• Second to be placed are the critical components like the microelectronics and the power supply systems placed next to the fixed components.
• The PCB supporting components such as the capacitors and the resistors are placed around the critical components.
• Finally, the PCB supporting elements such as the decoupling capacitors and resistors are placed.

Step 4: Connecting Routing

After the PCB components have been laid, it is time for connecting these components with traces. This process is referred to as PCB routing.

The four most common trace routing methods are:

• Manual routing – the designer does the routing manually by drawing a single trace at a time
• Semi-automated routing– there is a semi-automated feature in the design tool which a design uses to draw a single or many nets of the traces.
• Auto-interactive routing– here it is a combination of the manual and the semi-automated process.
• Batch auto-routing-the designer will do the routes manually and set several design rules to guide the process.

Step 5: Designing the 3D

This comes in after the PCB routing.

The designer will deliberate on the size of the PCB that is required and generate the exact size.

At this point, all manufacturing files are generated and delivered to the manufacturer for the process of manufacturing to be initiated.

In the next article, we shall have a look at the PCB manufacturing process and how we can order for PCB manufacturing in an online platform.

[PostWidget5]

[PostWidget1]

All over the world, we are surrounded by electronic devices. Whether we are working in offices or at homes, it is very easy to come across an electronic device. Some of them we walk with such smartphones, tablets, and laptops. Some are amazingly beautiful while others are subtle. All these devices have a board inside them that is referred to as a printed circuit board (PCB).

The printed circuit boards have been available since 1945 when they were discovered for military use during World War 2. When they were made commercially available, many manufacturers adopted them as the most suitable method for assembling electronics as compared to the traditional available point-to-point connection of the electronic circuits.

Over the years, the area of the printed circuit board has seen immense growth and also witnessed the introduction of new technologies in circuitry generation to meet the market demand and also to accommodate the new trends in the area of electronics. The knowledge about the electronic design and printed circuit boards can fill a shelve and today we are going to have a look at the basic introduction of it.

Definition of Printed Circuit Board.

A printed circuit board is an electronic rigid structure that is made of embedded metal wires referred to as traces/tracks and some large areas of metals referred to as planes. The electronic components are then fixed on the top, bottom, or even on both sides of the board using the metal pads. They can also be fixed on the sides of the board. The metal parts are also fixed on the boards to allow the components to be interconnected together. The board can be made up of a single layer of circuitry with components connected on either side or both or even can be made up of multiple layers of the circuitry that are stacked together.

• The board plane is made up of a dielectric material that is free from electrical conductivity so that it can be free from contaminating the electrical signals.
• The FR-4 is the standard material that is used in the production of the PCBs while the metal planes and the traces are made up of copper material.
• The printed circuit boards find great applications in many fields of electronics. You can find complex boards on computers and telecommunications and simple boards in child toys.
• Some boards are made up of specialized materials due to the high frictions and frequencies that they operate with such as high temperatures while others are made up of flexible materials so that they can be bent or even fitted in their areas of use. Also, some of the boards have heavy copper traces dues to their applications. In the current market, you will come across boards that have been built for extreme environments such as sensors that operate under high temperatures for example in car engines and boilers.

Although these are some of the noticed applications of the printed circuit boards, they all follow a similar construction process. Let us have a look at it below:

 

The PCB Making Process.

To come up with a physical printed circuit board, you must start by designing it. The design process starts with Electronic Design Automation which is made successful by the use of the design tool.

• The design process is divided into two stages

1. The schematic which involves the creation of the circuit connectivity in a diagram
2. The PCB layout involves the creation of the physical circuit board.

• Step number one involves the creation of the libraries that you need to use in your design. These libraries comprise the symbols, the footprints, and the 3D model of the components that you want to use.
• Once all the models are ready, the next things involve the creation of the schematic logical diagram. The CAD tools are used to place the symbols in the working space and interconnect them to form circuitry.

 

• At the same time, we have to simulate the circuit to ensure that it is functioning as it is intended. Once this is done, the simulated circuitry connection is passed to the next stage which is the PCB layout stage.
• At the layout stage, the schematic is received as nets that connect two or more components. With the outline of the PCB desired shape, the designer will place every component on their desired space.

 

• Once the components have been laid optimally, the next step is to connect the pins using the traces. The design tool will have several in-build rules and restrictions that stop the traces from crossing and touching each net and also control the size of the width governing each trace. Once the routing is completed, we shall have to use the design tool to generate all the documents required for the manufacturing process to be accomplished.

 

It is very clear that the design and manufacturing of the printed circuit board is a step-by-step process that starts with the design and simulation of the schematic, then the layout process where routing of the board is done, and also the generation of the relevant manufacturing files before delivering the final design to the manufacturer. The relevant manufacturing files that should be generated from the design tool include the pick and place files, the bill of material files, the GERBER files, and the drill files. The final step in the building of the PCB will involve assembling the BOM and building the final board. Let us have an in deep looking into these steps.

Important Files in the PCB Design and Manufacturing Process

During the process of the design of the PCB, before proceeding to order the PCB through the manufacturers’ site, there are different types of files that you need to generate using the Design Tool. Let us discuss them below:

GERBER files

They are the most common and also the most used files in the area of electronic design. They can be produced by almost all the EDA tools. In manufacturing, they are referred to as stencil data or light painting files.

The GERBER file is in two different types: RS274-X and RS274-D.

The GERBER file is a very crucial requirement in the design process, and if the file has inconsistent then the design will not be that good.

BOM files

BOM also known as a bill of the material file shows the list of components that are needed to make the PCB and does the matching of the components to the correct designator in the PCB layout. It also has a column for the source of the part, part number, and the manufacturer of the part. The file is in excel form as shown below.

Pick and Place Files

This is simply the list of all the components in the design and their respective coordinates and the rotation. Most EDA tools can generate the components’ x-y coordinates and how they have been rotated. They are always in excel form as shown below.

 

Types of Printed Circuit Boards

The printed circuit boards are classified into many different types depending of the number of layers that are available in the board and also the manufacturing process that was used. They are classified as follows:

Single-Sided PCBs

This is the most common PCB with a single copper layer above its substrate.

• The electrical components are placed on one side of this board. The conducting paths cannot intersect since it utilizes a single layer hence a lot of space is needed.

Double-Sided PCBs

A thin layer of conducting copper layer is added on both sides of the boards and holes drilled through the board allow the metal parts to be connected across both layers.

• These types connect the parts from one side to the other using one or two methods; ie THT or SMT.

Multilayer PCBs

This has more than two copper layers. Generally, a board featuring at least three layers will fall under this category.

What You Need to Know before Doing a PCB Design.

Many of us would like to become PCB designers. To some, it might be seen as an easy journey, and to others, it might become a complex journey. Here am going to take you through what you need to know before becoming an expert. First, you need to know the many electronic components involved in the design process. Secondly, you should have the know-how of the necessary EDA tools such as KiCAD, Proteus, EasyCAD, and many others which will help you in doing the design before sending the complete design to the manufacturer. Thirdly, we shall have a look at the different, materials that are very necessary for building the board used for the circuitry attachment and finally we shall see the manufacturing process is done especially the mass production. Let us start with the component.

PCB Design Components/ Elements.

PCB design starts with an Electric Circuit. An electric circuit is an interconnection between components of various types and purposes in which there is at least one enclosed path in which an electric current can flow as shown in the image below.

performance of a system be it mechanical or electrical is done by drawing of its electrical circuit equivalent. by simulating this circuit, any system can be studied. This tells us that the performance of any system can be studied by mastering its circuit theory.

Below are the elements that are commonly used in electronic circuits;

Active elements:

are elements of the circuit that have their energy. They are independent of an external power source. They are of two types that is a current source and a voltage source.

Passive elements:

these elements do not possess energy of their own. They depend on an external source of energy. This is the area of focus of this article and therefore more discussion will follow. An example of this is a resistor.

Linear and non-linear Elements:

• Linear elements show the linear characteristic of the voltage and current which is in most cases a straight line. Example a resistor.
• For the non-linear elements, the v-I do not follow a straight line. Example diode

Bilateral and unilateral elements:

Bilateral elements have the same relation existing between voltage and current for current flowing in bi- directions. Example current source.

Unilateral elements do not have the same relationship existing between their voltage and current flow. Example a silicon diode.

Lumped and distributed elements:

Talking about the lumped element, our focus shifts to those very tiny in size elements in which actions take place simultaneously. We can have a few examples such as resistors, inductors, and capacitors.

On distributed elements, we can define them as those elements that are not separatable electrically for analysis. They include for example a transmission line that has distributed parameters along its length and may extend for hundreds of miles.

Now after having a reminder on what electrical elements are, let us go back to the purpose of this article. Our focus is on passive elements and we have already introduced what they are in our introduction.

Passive Electronic Components.

Passive elements are those elements that do not possess energy of their own. They are dependent on an external source of energy such as a current source or a voltage source. These elements do not generate power but they dissipate energy.

Passive elements are part of electronic circuits. 99% of the circuits we have around have either one or more passive elements. Before we get deeper, I would also like you to know that we have different techniques of how to fix components on a PCB board. Yes, two methods;

• Through-hole technique; the PCB board has holes drilled through them where the components with long legs are fitted through and soldered. It was the first method to be used although today it is not in much use.
• Surface mounting techniques; in this technique, the components or elements are laid on the surface of a PCB board then it is interconnected through copper pores. This is the latest technology that has led to the generation of compact and small components hence leading to reduced board sizes.

Having this in mind, it is very important to note that, passive elements also exist as a through-hole device (THD) or as a surface-mount device (SMD).

 

Let us now shift our focus to some passive elements that are commonly in use and are used. This will give us an early signal on things to consider while using passive elements. You cannot use an element without knowing what it is, what it does, and where to use it.

The Material used in the PCB Manufacturing

There are three types of PCBs and all will have different types of material. However, they all have similar primary materials. below, we are going to have a discussion on the different materials used in the manufacturing of the printed circuit boards.

Substrates

This forms the base of any printed circuit board upon which the manufacturer will mount the components and create the circuit to make the board complete.

• The type of the board is depended on the type of material that forms the base.
• Mainly there is the availability of two materials that are commonly used by the manufacturer to form the base of any given PCB namely; the fiberglass substrate and the plastic substrate.
• The fiberglass substrate is best suited for rigid, strong, and flexible PCBs used in the area of medicine.
• The plastic substrate is the cheapest option and also the most flexible option. Therefore, most manufacturers go for the plastic substrate. Plastic substrate durability is dependent on which type of material is used which includes; liquid crystal, polyimide, and polyester.

Conducting Material

Besides the nonconducting substrate, in any given printed circuit board is the conducting material that facilitates the creation of the traces and the completing of the circuit. This is made up of copper material.

• How the copper sheet is laid is defined by the designer depending on the usability of the board.

Solder Mask

This is a protective layer that is used to insulate the copper traces and protects them from damages such as short circuits and environmental dust and moisture.

• Without the soldering mask, oxidation will take place on the solder liquid hence making the circuit stop working.
• Besides the protection function, the solder mask determines the color of the printed circuit board.
• The most common color is green, but manufacturers have come up with solder masks of different colors such as blue, red, etc.

[PostWidget5]