If you have a laser printer, you can make your own printed circuit boards (PCBs) for electronic hobby projects. The materials are inexpensive and easy to find. The laser printer makes an accurate toner pattern on the paper, and the toner protects the copper from the etching process, producing clean traces on the board. The right laser photo paper is key to a good circuit board because you need to transfer the toner pattern from the paper onto the board. With a little practice this process yields near-professional quality circuit boards.
Instructions
1 Prepare the bare board by scrubbing the copper side with the scotchbrite pad under cold running water. This will remove any oxide and leave the copper clean and ready for etching.
2 Set the laser printer so it prints at maximum toner density, or darkest image, if your printer has this control. Before you print the PCB design graphic, ensure you create a mirror-image copy of the original and print that version. Since this will be a transfer, you need to print a mirror image. Place the paper in the printer's manual-feed slot so it will print on the paper's glossy side. Print two copies of your design to have a spare in case the first doesn't work.
3 Turn the iron on to its maximum setting and let it warm up. Trim the margins of the printed PCB design, leaving one side with some excess. Lay the bare PCB, copper side up, on the wood board. Place the trimmed PCB design toner-side-down on the PCB board, ensuring any registration marks on the design line up with the board's edges.
4 Press down on the paper with the hot iron. Keeping the paper stationary, slide the iron back and forth around to ensure the paper heats evenly. Iron the paper for several minutes, then remove the iron and let the board cool. Your first board may not turn out perfectly, but with practice you'll learn a combination of time, pressure and movement that works.
5 Put the board in the tub of moderately hot water and let it soak 30 minutes. Take the board out of the water and begin peeling the paper off. Use the old toothbrush to gently scrub off stickier parts of the paper. When you've removed the paper, let the board dry.
6 Don the plastic gloves and safety goggles. Place the board in the soaking tray and pour enough etchant into the tray to cover the board. Let the board soak in the etchant for 15 to 20 minutes or until the etchant has removed the visible copper. Remove the board from the tray and rinse it with cold water. Wash the toner from the board by lightly rubbing it with acetone, rinse the toner off, and wipe the board clean with a paper towel.
