HOME MADE PCB

HOME MADE PCB

Printed Circuit Board or PCB is generally used to mechanically support and electrically connect the components with help of conductive path ways or traces made on copper clad sheet. In another words PCB is used to create a electrical connection between different components like resistor, capacitor, integrated circuits,IC’s etc.

In general PCB has two sides-

1. Front side – Also known as Components side, which is used for placing variety of electronic components.
2. Back side - Also known as Track side, which is printed with electrically conductive pathways for connecting the components.

For making a PCB following things are require-
1. Copper clad sheet
This is available in different size and dimension. You have to select the size of sheet according to your circuit. Thickness of copper clad sheet also plays an important role, used thickness equal to 1.2 to 1.5mm approx. because it will start bending if you have used sheet of less thickness.
This also has two sides-
a. One which has copper on its side used for making traces or used for soldering the components.
b. And another side has plastic or bakelite used for mounting the components.
Note-Before using the copper clad sheet wash it properly no dirt or water vapor should be present on it or you can also use pencil eraser to clean the surface of PCB.
2. Ferric chloride solution
Also known as FeCl3 used to remove the unwanted copper from the copper clad sheet or used for making conducting path. Time of etching depends on the concentration of FeCl3 mixed with water. Basic ratio may be 50gms Ferric chloride in 100ml of water.
Please take care-FeCl3 is a toxic solution and can cause skin burn and irritation so be careful, use hand gloves during etching, if contacts happen with FeCl3 immediately wash with water.
Kindly do not through the remaining FeCl3(after etching) into the drain because it contain copper ions which are dangerous, neutralize it with the help of sodium Carbonate or sodium hydroxide  and check the ph value it should be approx7-8 before disposing it or you can add more water to dilute it.
3.  PCB drilling machine and drill bit
Drill machine are used to make hole in PCB for mounting the components. While drilling the PCB you should be very careful about the size of hole because different components leads have different size. Kindly measure the leads before drilling. In general use following sizes for making hole for different components.
a.1mm-for IC Base
b.1.2mm-for Resistor,Capacitor,Transistor,LED
c.1.5mm-for Diodes,Preset
d.5mm-for Nuts,Screws
e.8mm-for Switch

4.  Permanent Marker, sticker paper, Iron, Whitepaper, Cello tap, Tray for etching, Scrubber for cleaning PCB.

Steps for making PCB are as follows-

1.  First draw your required circuit diagram on paper.

2.  Now take sticker paper remove the front part and put above you circuit and only draw conducting path and drills points. Be careful do not overlap the conducting traces. Like as shown in fig. below.



3. Now darken the layout with the help of permanent marker draw carefully there should be no overlapping or shorting of tracks or components. As neatness of PCB lies in pattern drawing. You can also take the print out of the same on sticker paper.

4. Now carefully cut the required copper clad sheet and wash it properly. Now place the sticker paper on copper side of copper clad sheet.

5. Carefully cover the sticker paper on copper clap sheet with the help of tap. Be careful there should be no air bubble inside.

6. Now take a iron(used for ironing clothes) set the temperature to approx. in middle and iron your sheet on the sticker paper side by applying pressure for approx.10 minutes.

7. After that put your PCB underweight if you do not do this then there is a chance that your PCB may bend. Keep it until it become cool.

8. Now remove the paper very slowly and see you have transformed the print on copper clad sheet.

9. Now carefully examine the sheet for shorting, missing of tracks with help of circuit diagram.

10. Now again darken the traces with the help of permanent marker.

11. Fill the extra space present on Copper Clad Sheet with marker it will save your etching time. Like shown in Fig.



12. Now put your PCB in feCl3 solution for etching keep it for 15 minutes then see if it is properly etch or not.

13. After this wash it properly with the help of Scrubber. Your PCB may look like this.




14. You can tin your tracks with the help of solder wire it will prevent oxidation on pcb from environment hence increases the life of your pcb.

Your PCB is ready for use