After you've built prototype electronic circuits using perfboard and breadboard, you'll want to make something more permanent and professional on a printed circuit board (PCB). Electronics manufacturers have an array of expensive machines churning out PCBs by the thousand. You can make one for yourself inexpensively using household items and some common chemicals. It requires that you print your circuit board's design to paper, transfer it to a board and etch and drill it . The process takes an evening or two.
Instructions
1 Create the PCB artwork as a printable computer graphic file. Draft a schematic on the computer using electronic design software, then use the program to convert the schematic to the printed circuit artwork. If you're building a printed circuit based on artwork someone else has produced, download the file or scan the printed pattern into your computer.
2 Scrub the bare copper board with the Scotch-brite pad under cold running water to remove oxides and dirt. When the copper looks bright and shiny, dry it with a soft towel and set it aside.
3 Insert a few sheets of laser photo paper in the laser printer's manual feed slot. Make sure the printer will print on the paper's glossy side. Set the printer so it will print at maximum darkness. Print a few extra copies of the printed circuit design in case you have problems with the first one.
4 Use scissors to trim the margins of the printed page to the dimensions of the bare copper board. Allow some excess on one edge to make removing the paper easier. This part will hang over the edge of the board slightly.
5 Plug the iron in and set it to maximum heat. Place the wood board on a sturdy work surface. Lay the bare PCB on the wood board, copper side up. Lay the printed paper on top of the PCB, print side down. Adjust the paper so the edge you left longer in Step 3 hangs over the side of the copper board.
6 Press down firmly on the printed paper with the iron. Move the iron around every few seconds, but make sure the paper doesn't slide around on the copper board. Keep pressing and moving the iron until the paper underneath takes on a glossy appearance. The paper may turn slightly brown from the heat, also. This should take about 5 to 10 minutes.
7 Fill a tub with moderately hot water and place the board in it. Keep it in the tub for 10 to 20 minutes, or until you can peel some of the paper off. Remove the paper in layers until you reach the glossy part closest to the copper board. Use the toothbrush, if necessary, to remove the last layer until the paper is gone, leaving a circuit pattern of black toner on the copper surface.
8 Put the gloves and safety goggles on. Place the copper board face-up in the glass tray and pour enough ferric chloride etchant to cover the board to a depth of about 1/2-inch. Allow 10 to 20 minutes for the etchant to remove the unwanted copper. Every few minutes, gently nudge or rock the tray to keep fresh etchant on the copper. Remove the board from the tray when you no longer see copper on the board.
9 Rinse the board under cold running water for a few minutes to wash the etchant off.
10 Pour a small amount of acetone on the toner patterns on the board and gently rub with the small sponge. Do this until all the toner is gone, revealing bright copper traces. Rinse again under cold water and dry the board with a paper towel.
11 Insert the #68 drill bit in the drill press's chuck and tighten. Place the flat wood board on the drill press bed and put the printed circuit board on top of it, copper side up. Drill the holes for capacitors, resistors and other leaded parts. If your circuit board needs holes for integrated circuits, switch to the #71 drill bit.
