When I got started with making my own printed circuit boards (PCBs), I found a plethora of ways and methods. However, very few seemed to work properly. Toner transfer seemed the most straightforward, with several companies offering special papers designed to make the process easy. But these were expensive, and the results were not nearly as good as promised.

The best toner transfer method seemed to be the old toner transfer-to-magazine paper trick, but I always ended up with a few missing traces in the end. However, after doing some experimentation, I discovered a ‘process’ that seems to yield the right result almost every time! I call it my 2-5-2-2 Perfect PCB Toner Transfer Process. Here it is.

Print your PCB Artwork

This is the easy bit. Assuming your artwork is all to scale (and reversed – don’t forget if you don’t mirror image your artwork, when you iron it it will appear backwards). You simply print it from something like photoshop to a decent laser printer. I use an HP LaserJet 4250. The toner itself seems to be a point of contention, with some saying the compatible toners don’t work. However mine has a compatible cart and works fine.

Carefully tear out a piece of magazine paper from a… magazine. You want something glossy but not too glossy. I pull out the regular pages from HotRod Magazine. Their paper is really good quality. Plus, I can read about awesome car projects I’ll never be able to afford!

When printing, the crucial thing is to make sure the printer knows what type of paper it’s handling. I use Photoshop, so in the printer settings I tell it the paper is heavy glossy. This causes the printer to do two things: 1) draw from the manual feed tray and 2) pull at a slower speed so more toner affixes to the page. You want this because you want the toner to be solid and not too thin, otherwise it won’t protect your traces from the etchant properly.

Once printed, you’re ready to prep your copper clad.

Prepping the Copper Clad

This is very important. Copper needs to be slightly roughed up for your toner to get a good grip on it. I use a Scotchbrite pad and some Comet, dry, not wet and I scrub at it like crazy for at least a minute, everywhere I can in random patterns. I then rinse in fairly warm water until clean. Next, I wipe the board down with some paper towel and acetone.

Ironing

This is the bit that always trips people up. Many recommend ditching the iron for a laminator. But if you don’t have the money to dish out on fancy new equipment, an iron (you don’t care about) will do just fine. It’s all about technique, heat, and pressure. First, set your iron to the hottest setting (usually cotton). Do not set it for steam. You don’t want steam at all here.

Next, put your copper clad on your work surface (in my case, it was a kitchen counter) with the copper side up. Place a piece of parchment paper over it. Set a timer for 2 minutes and begin moving the iron slowly back and forth, up and down, all over the board to get it nice and hot.

The reason I use parchment is because I found magazine paper/ink will melt and become gummy, binding on your iron. Over time, this will wear off the non-stick coating on the iron surface. The parchment paper reduces friction considerably.

When your timer goes off after 2 minutes, remove the iron and parchment paper.

Now you’re ready to align your magazine paper with the artwork printed on it. Align it over the board and do not let the magazine paper touch the board until you have centered or aligned properly. The second it makes contact with the hot copper, it’ll stick.

Bring the magazine paper gently onto the copper clad surface. Now place your parchment paper over it.

Set your timer for 5 minutes and start ironing the whole of the magazine paper underneath. What I do here is a few ‘sweeps’ from side to side, sort of ‘laminator like’. Slow and with lots of pressure. Then I imagine in my mind’s eye where the traces and pads are and give a fair bit of pressure (not too much) and put a bit of extra pressure on the tip of the iron to get all those places pressed down nicely. I also do a lot of light sweeps back and forth, up and down all over the place to get the heat nice and even.

When your timer goes off after 5 minutes, remove the iron and set it aside. Leave everything else as is.

Set your timer for 2 minutes, and walk away. I honestly do not know why but this ‘cooling process’ seems to help. While giving it a rest, fill a sink or bucket with cold water. This is what the PCB will be dunked into once we’re done.

When your timer goes off after 2 minutes, set it for another 2 minutes. Take your iron and again repeat what you did for the previous 5 minutes. Really work the iron one more time along where traces, pads, etc will be.

When your timer goes off after 2 minutes, remove the iron, put on an oven mitt. Remove the parchment paper, then grab the board. The paper should be firmly stuck to it. Dunk it directly into your sink. Let it sit for a good couple minutes. The longer it sits, the more the water will break down the fibers of the paper and make it easier to separate from the board and toner. Gently peel the paper away, following the directions of traces where possible.

Voila! A nice, crisp transfer! And no need to spend money on fancy blue stuff!

Now you can trim off the excess, and proceed to your favourite etching method. I will discuss mine in a future post.