How to make a PCB (DIY) at Home

Introduction
In today’s world executing college projects is becoming more and more competitive and time consuming. Added to this, the final exam scores are also dependant on how well the project is conceived, executed in time and it actually works ;-).

I myself struggled a lot while executing college projects which were electronic hardware based. The one constant worrying factor was “how to make a PCB”? The PCB should be according to my requirements and my design. And now I have somewhat mastered the process of making a PCB and here are directions for making it yourself (Do-It-Yourself).

Steps to make a PCB at Home
1.  Designing the PC
2.  Printing the PCB Design
  • OHP Transparent Sheet (thinnest)
          It is advisable to find the thinnest sheet so that it facilitates easy ironing on to the PCB without crumpling etc.
  • Laser (B & W) Printer
          The method used here is called toner transfer method
3.  Obtaining the required components
           Components Required:
           - PCB Copper Plates (size of your design)
             Choose one which is slightly bigger than your PCB design borders. Too much space outside the design border will waste copper and cause longer time to etch.
          - PCB Etching Powder
             The etching power is actually the Ferric Chloride powder that I have used and easily available in shops in India. You can ask simply for PCB etching powder also.
          - Iron Box
          - Water Pump (used in Fish Aquarium)
             Usually this costs around Rs. 100 and is available in Fish Aquarium shops. Make sure you also get the plastic tube attached to the pump.
          - Scissors and Tape
          - Wire Mesh Scrubber
4.  PCB Etching

Procedure
  • Once we have the designed circuit ready (I used Eagle software tool), it can be now printed on the OHP transparency sheet using the laser B & W printer. Ensure it is slightly high quality print (look for the OHP mode in the laser printer options).
  • Take the copper plate and scrub it nicely with the wire mesh scrubber. Ensure the copper plate is clean and fresh and does not have any finger prints, dust or grease and is DRY.
  • Cut the PCB design printed on the transparency sheet to the exact dimensions it is printed. (around the border). Place the ink side of the design on the copper plate and neatly tape it to the copper plate on all four sides so that there is no air gap.
  • Set the iron box heating needle to “cotton”, place a cloth on the PCB design and press the iron on the design and apply pressure all around the design as much as possibly (it’s the pressure that is more important than the heat). Do this for 3 minutes or so. If the PCB size is more than 4” x 6” then remove the cloth and apply the iron directly (This is so because the larger PCB act like heat sinks and radiate the heat fast). Once the heating is done immerse the PCB immediately in a bucket of normal water.
  • Peel off the taped OHP design while the PCB is still immersed in the water. At this point most of the ink would have transferred to the PCB. If any part of the ink has not got transferred to the PCB you can touch up using a permanent/CD marker pen.
  • Take half of the etching powder packet and dissolve it in around 250ml of water and pour in a suitable plastic container. Ensure there are no iron or steel plates around since this liquid is an acid solution that corrodes metals. It may sometimes be allergic to your skin.
  • Plug in the aquarium pump, switch on the power and insert the free end of the plastic tube into the plastic container. The water bubbles will start appearing. Place the PCB with the printed design such that it is fully immersed in the liquid. If the PCB is large, you can immerse one half after another by rotation.
  • After some time you will see that all the copper has dissolved (it looks as bald as the other side of the copper plate) leaving only the etched design. Remove the PCB, wash in water and with a cloth and acetone/kerosene you can clean and remove the ink off the copper plate.
Your PCB is ready for use now.
  Tips:
  • To increase etching speed, increase the concentration of the solution by adding more powder to lesser water.
  • It is advisable to drill holes in the PCB before etching right after ironing so that all touch up can be done after drilling.

Printed Design

Copper Plate

Aquarium Pump

Printed Design

Accessories

Immersed in Liquid

PCB Ready