First of all: I have the habit of making things and not photographing it. I beg your pardon.
I needed a breakout board for development of ATmega32U4 firmwares, making entire keyboard PCBs to test one thing or two is expensive. A
Teensy costs $16, but have a custom bootloader.
Adafruit's breakout board costs $20, plus shipping, import taxes and takes a while to be delivered. So I decided to go back to my technical school times and hand make my own PCB.
Made the design using EAGLE, pretty straightforward. Just the 32U4 will be soldered on board, everything else will be on protoboard when prototyping.
I have gathered over the years much knowledge about toner transfer method. I have a GBC H-220 laminator, like this one:
, and made a
mod for better toner transfer. This laminator isn't made anymore AFAIK.
Next, I printed the design on inkjet glossy paper on my laser printer, cut it out of the sheet and used the laminator to make the toner transfer. After 4 passes I soaked the PCB and removed
gently the paper from it. Take your time when doing that.
Now I only had to do the etching. Problem: I don't have ferric chloride here at home. I also don't have muriatic acid to combine with hydrogen peroxide. So I went to a relatively unknown etching method: hydrogen peroxide + salt + vinegar.
Obviously, because I wanted to finish this board today, Murphy's Law came in action and I had too little hydrogen peroxide at home. Made the solution anyway, just for a proof of concept. When the solution became saturated, I removed the PCB, rinsed it and removed the toner. The result is this:
The copper isn't completely etched, there is some toner still attached to the board and I didn't aligned the design with the holes I already had made the other day, but I'm pretty happy with the result. You can see that there was some etching, enough to separate the traces from the etched copper. The traces are 16 mil (0.4064 mm), pretty good resolution for a home made PCB.
The only thing that you must be aware is that this method is slow. At least the remaining by-products of the described method are not as toxic, so it is safe to dispose it on the bin.
More information
here. I'll be happy to answer any question to the best of my knowledge. And tomorrow I'll buy (way) more hydrogen peroxide and etch another PCB (the same design, but I'll probably make a change or two).
