halcy :icosahedron:
boosted
wheeee! I've successfully made a glass PCB! 0.1mm copper foil laminated onto a microscope slide using two component epoxy and a hot roller laminator, coated with cheap aliexpress dry film photo resist and etched in copper chloride.
turns out that most of my struggles during etching came from my bad exposure setup. The light source was way too diffuse and I way over exposed the photo resist. Going from 7.5 minute exposures down to 20 seconds really helped and switching from a very diffuse UV exposure box to a UV spot light mounted around 50cm away finally got me to an acceptable result.
Of course the one that ended up working was on my ugliest piece of copper on glass laminate but whatever. It finally works!
Closeup of the right most PCB. It's got some small flaws but looks totally serviceable. The lamination job on this one wasn't to great, so the epoxy between the traces looks a little lumpy and the copper is slightly pitted. It look… rustic?
Three tiny copper on glass PCBs made on microscope slides, getting more crisp, less blobby and less oxidized going from left to right. The one on the left has tons of bridges between traces, most of them are just kinda melted together. The middle one is a little better and the right most one is a perfectly serviceable PCB. It's got some flaws from bubbles under the photo resist, but nothing that would keep it from working
