PCB etching at home

      Comments Off on PCB etching at home

When you need a PCB in a hurry and don’t want to wait for it to be made by a professional company, you can always etch one at home like the old days.

First, you create the layout like any PCB. For this project, I’m etching the PCB for the Pi-UPS project.

Then, export the copper face, scale it to the correct size, and print it to check for component fit. If all is well, mirror it, and print it out on Inkjet High-gloss photo paper but using a laser printer. This will make it extemely easy to transfer to the raw copper on the blank PCB.

Clean off the PCB with a scouring pad to clean off any oxides or impurities, put the print layout face down, and iron it on with a clothes iron on maximum heat setting. Give it a good minute or two to make sure its fully stuck down.

Soak the paper in water to dissolve it, and use the scouring pad to remove any residue. This will probably damage the printout slightly, fix any mistakes with a waterproof black marker.

Dunk the PCB in etching solution. I use sodium persulfate. Take proper precautions when working with the stuff, read the MSDS beforehand. For it to work properly, the water has to be at least lukewarm. Gently stir the pcb so the surface bubbles don’t stick and cause print defects.

After the PCB has etched, clean off the toner with some paint thinner or other solvent. Cut the boards to size, and drill any holes required for through hole components. On this project I only needed one board, but made 4 just to make sure I had at least one good one. Home etching isn’t perfect. It is however, very quick for prototypes.

You can see where I ..fixed.. the boards with a broad tip marker.

One good, one decent, one meh and one bleh. I only really needed one though, so no problem.

And this is what it looks like after transplanting over the components. Its not the best board ever, but it will do the job. And I didn’t have to wait days or even weeks for the board to arrive.