Making Printed Circuit Boards with Acetone Transfer

I made a printed circuit board for developing a homemade measuring instrument.

Acetone Transfer

Print on plain paper with a laser printer, then place the printout on a copper board, wet it with water, and press the paper firmly. Next, apply a small amount of acetone and, from above a clear file, rub the toner onto the copper board with your fingernail to transfer it with acetone. The first time, I used too much acetone and failed. It's just right when it's soaked throughout. I used 100% acetone nail polish remover.

Wash and rub with water to remove the paper.

Etching

Pour the etching solution into a suitable container and warm the solution to body temperature using a freezer bag filled with hot water for etching. Around 40 to 45℃ seems to be good, but I didn't use a thermometer as it would rust, so I just estimated. Visually confirm that the copper in the unmasked areas has dissolved, then stop etching.

Dissolving the Coated Parts

Dissolve the parts masked with toner or permanent marker using acetone. This leaves only the copper in the masked areas, creating the circuit.

Making a Small Circuit

I drilled holes and soldered to make a small circuit. It was easier to solder by applying it as if laying it on top of the copper.