Circuit Board making- The best way to make PCB at home
From our STAR Maker: Suraj Gehlot
If you are into electronics, PCBs are the most common things you will see. These boards make our lives easier by eliminating all those connecting wires and breadboards. If properly designed, it even makes our project look smaller and sexy.
What is a circuit board? A printed circuit board (PCB) mechanically supports and electrically connects electronic components using conductive tracks, pads and other features etched from copper sheets laminated onto a non-conductive substrate.A printed circuit board has pre-designed copper tracks on a conducting sheet. The pre-defined tracks reduce the wiring thereby reducing the faults arising due to lose connections. One needs to simply place the components on the PCB and solder them.
In this cool tutorial, I will show you how you can make circuit boards at home easily. Doing so will save you a lot of time from debugging and double checking the connections on a breadboard. You could even make your own arduino after going through this tutorial: DIY Arduino and the current one. So, sit back and see how its done really easily :)
What are the different ways to make a Circuit Board?
There are in all three basic methods to make PCB:
- Iron on Glossy paper method.
- Circuit by hand on PCB.
- Laser cutting edge etching.
Since laser method is industrial method to make PCB we will get in detail of first two method to make PCB at home.
PCB design is usually done by converting your circuit’s schematic diagram into a PCB layout using PCB layout software. There are many cool open source software packages for PCB layout creation and design.
Some are listed here to give you a head-start:
- Cadsoft Eagle (http://www.cadsoftusa.com/download-eagle/?language=en)
- PCBWizard (http://pcb-wizard.software.informer.com/4.0/)
Design your circuit schematic in Cadsoft Eagle:
In Eagle: File> Export>ImageBe sure to set DPIG to 1200 for better quality
What are the stuff required to make a Circuit Board?
You also need: FeCl3 powder/solution (same as etching solution), photo/glossy paper, permanent black marker, blade cutter, sandpaper, kitchen paper, cotton wool.
For this tutorial, lets consider making a PCB for a simple project- a Touch Switch using IC555.
STEP 1: Take printout of circuit board layout
Take a print out of your PCB layout using the laser printer and the A4 photo paper/glossy paper. Keep in mind the following points:
- You should take the mirror print out.
- Select the output in black both from the PCB design software and printer driver settings.
- Make sure that the printout is made on the glossy side of the paper.
STEP 2: Cutting the copper plate for the circuit board
Cut the copper board according to the size of layout using a hacksaw or a cutter.
Next, rub the copper side of PCB using steel wool or abrasive spongy scrubs. This removes the top oxide layer of copper as well as the photo resists layer. Sanded surfaces also allows the image from the paper to stick better.
STEP 3: Transferring the PCB print onto the copper plate
Method 1 Iron on glossy paper method (for complex circuits): Transfer the printed image (taken from a laser printer) from the photo paper to the board. Make sure to flip top layer horizontally. Put the copper surface of the board on the printed layout. Ensure that the board is aligned correctly along the borders of the printed layout. And use tape to hold the board and the printed paper in the correct position.
Method 2 Circuit by hand on PCB (for simple and small circuits): Taking the circuit as reference, draw a basic sketch on copper plate with pencil and then by using a permanent black marker.
STEP 4: Ironing the circuit from the paper onto the PCB plate
- After printing on glossy paper, we iron it image side down to copper side. Heat up the electric iron to the maximum temperature.
- Put the board and photo paper arrangement on a clean wooden table (covered with a table cloth) with the back of the photo paper facing you.
- Using pliers or a spatula, hold one end and keep it steady. Then put the hot iron on the other end for about 10 seconds. Now, iron the photo paper all along using the tip and applying little pressure for about 5 to 15 mins.
- Pay attention towards the edges of the board – you need to apply pressure, do the ironing slowly.
- Doing a long hard press seems to work better than moving the iron around.
- Here, the heat from the iron transfers the ink printed on the glossy paper to the copper plate.
CAUTION: Do not directly touch copper plate because it is very hot due to ironing.
After ironing, place printed plate in luke warm water for around 10 minutes. Paper will dissolve, then remove paper gently. Remove the paper off by peeling it from a low angle.
In some cases while removing the paper, some of the tracks get fainted. In the figure below, you can see that the track is light in colour hence we can use a black marker to darken it as shown.
STEP 5: Etching the plate
You need to be really careful while performing this step.
- First put rubber or plastic gloves.
- Place some newspaper on the bottom so that the etching solution does not spoil your floor.
- Take a plastic box and fill it up with some water.
- Dissolve 2-3 tea spoon of ferric chloride power in the water.
- Dip the PCB into the etching solution (Ferric chloride solution, FeCl3) for approximately 30 mins.
- The FeCl3 reacts with the unmasked copper and removes the unwanted copper from the PCB.
- This process is called as Etching. Use pliers to take out the PCB and check if the entire unmasked area has been etched or not. In case it is not etched leave it for some more time in the solution.
Gently move the plastic box to and fro so that etching solution reacts with the exposed copper. The reaction is given as:
Cu + FeCl3 = CuCl3 + Fe
After every two minutes check if all the copper has been removed. If it hasn’t then place it back in the solution and wait.
CAUTION: Always use gloves while touching the plate having the solution.
STEP 6: Cleaning, disposing and final touches for the circuit board
Be careful while disposing the etching solution, since its toxic to fish and other water organisms. And don’t think about pouring it in the sink when you are done, it is illegal to do so and might damage your pipes (hehe, who knew you could get arrested while making a PCB!). So dilute the etching solution and then throw it away somewhere safe.
A few drops of thinner (nail polish remover works well) on a pinch of cotton wool will remove completely the toner/ink on the plate, exposing the copper surface. Rinse carefully and dry with a clean cloth or kitchen paper. Trim to final size and smoothen edges with sandpaper.
Now, drill holes using a PCB driller like this: PCB driller and solder all your cool components. If you want that traditional green PCB look, apply solder resist paint on top: PCB lacquer. And finally! your super cool circuit board would be ready!
An electronics engineering student from the University of Mumbai. I’m a Maker/TechCrazy/Innovator who is passionate about technology and electronics.