Here’s How to Etch a PCB Right Onto Glass

Professional PCB (printed circuit board) fabrication is quick, easy, and affordable these days through a number of services. But, that’s a fairly recent development. For decades, DIY’ers had to make their own PCBs at home using a chemical etching process. With the services available today, there isn’t much reason to go through that trouble for a conventional PCB. But, as Hdissanayake demonstrates in their tutorial, the process can be adapted for interesting applications like putting a PCB on glass.

This process will work with any material that can hold up to the heat of soldering and the chemical etching process. Glass is a great choice, but you could also make your PCB on metal or something exotic like stone. In conventional PCB etching, you buy a sheet of copper that is already applied to a rigid substrate. Then, you mask your design and etch away the copper you don’t want. This technique simply adds an extra step where you apply copper foil to the substrate of your choice manually.

To do that, you’ll need whatever substrate you want to work with, UV photosensitive film, copper foil, and an overhead project printout of your PCB design (you can print those at office supply stores). That printout should be black in the areas you don’t want copper, and transparent where you do. You’ll also need the etching chemicals, which include baking soda and ferric chloride.

First, you glue the copper foil to your substrate. Then apply the photosensitive film over that. Next, put your printout over the film and expose it to UV light. Remove the top layer of the film and put it in a bath of baking soda and water to develop it. Finally, put it in a second bath of ferric chloride and water to etch away the unwanted copper. That’s it! You’ll have a nice PCB on whatever substrate you chose. Obviously, through-hole components aren’t going to work well with this, but it should do fine with SMT components.