Etching Circuit Boards with a 3D Printer

We're very lucky these days, because it is easy and affordable to have professional PCBs fabricated and mailed to our doors. The turnaround is often quick, with even the cheapest options arriving within a couple of weeks. But sometimes you need a PCB right away so you can test a new prototype and move through development without waiting weeks between iterations. If that is the case, you may want a way to fabricate simple PCBs at home. To do so, Redditor Malendryn came up with a technique for etching circuit boards with a 3D printer.

This is a variation of a tried-and-true etching process that was popular among makers before affordable PCB fabrication services came along. This relies on chemical etching of the copper on PCB blanks, with the traces and pads masked. There are many different versions of the traditional process, but one method is to print the mask onto paper using a laser printer. It is then possible to transfer the toner onto the PCB blank with a hot iron. The toner masks the copper you want to keep, so the etching chemicals can dissolve the rest of the copper and leave only the substrate.

Malendryn's process saves quite a few steps, because it applies the mask directly onto the PCB blank. Malendryn attached a Sharpie marker to their 3D printer's tool head using a binder clip and a simple 3D-printed mount. They then converted an image of the PCB into a g-code file for the printer to follow, so it acts like a pen plotter. The Sharpie draws the mask onto the copper, which Malendryn then etched with muriatic acid and hydrogen peroxide.

Malendryn reports very good results, with only minimal post-processing required. The best part is that this doesn't require any permanent modification of the 3D printer, so Malendryn can switch back to 3D printing whenever they want. They designed the mount to fit their Creality Neo 3D printer tool head, but the concept will work with any 3D printer that accepts custom g-code. If you're looking for a way to fabricate PCBs at home, this technique could be very useful.