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How to Make a Printed Circuit Board - Toner Transfer Method

Making your own printed circuit boards at home is a cheap alternative to ordering a batch from one of the many pcb manufacturers. Using simple household items you can set up your own home pcb etching station to start making your own custom pcb's.

Before starting to put together your etching station, you need to make sure you understand the whole process and the materials you will be using, since you need to handle an acid solution in the etching process. Make sure to take special precaution when developing your boards, such as using gloves, eye protection and working in a well ventilated area.

The materials needed to get your etching station to work are easy to get, some you may already have in your home. Since we are going to be using the toner transfer method, you'll need a laser printer to print your designs so you can transfer them to the board.

To actually transfer the design, you'll need to print it to photo paper or other high gloss such as magazine paper, that is because we need the printed toner of the laser printer to remain in the surface of the paper, because otherwise the toner will stick to the fibers of regular paper and the transfer will not be reliable. Another thing to consider is that you will need to print a reverse or mirrored image of your design, so that when you transfer it the tracks and letters have the correct orientation.

Now that you have your design, it's time to transfer it to the blank circuit board, also called copper clad board. These boards have a copper laminate over a non conductive substrate such as fiberglass epoxy of the common FR4 board. These boards are easy to get, as many hobby and electronics shops have them, or you can also order them online.

Make sure to clean the copper surface so as to remove any oil or oxide that may have formed in the surface before the transfer, or the toner may not stick and cause broken tracks.

To make the transfer, place the gloss paper with the printed design facing the copper laminate and apply pressure with a clothes iron in the highest setting with no steam. Use the iron to apply general pressure on the whole surface of the board, after a little while, use the tip to apply localized pressure on areas of the board to make sure the toner melts and sticks to the copper. Corners and high density areas of the design need special attention in this heat and pressure step.

The transfer should now be stuck to the copper, to remove the paper just soak the board in warm soapy water and peel the paper as soon as it gets wet, just make sure not to use too much pressure or the toner may also rub off.

The final step is to actually etch the board to create the tracks. There are two common acids that you can use, on is ferric chloride, available at most electronics shops, the other is using muriatic acid and hydrogen peroxide. The formulas and methods to use the acids to etch are an art and science of their own, and that is outside the scope of the article. It usually involves placing the board in the acid and wait for the exposed copper to get dissolved in the acid.

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