Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

I've been pondering methods to improve/hasten/detoxify homemade PCBs, and had a thought occur yesterday: bead blasting. has anybody tried this or seen it done?

There are numerous types of photosensitive laminate out there, including hardier varieties created specifically for blast-etching. The same goes for blasting media, which is available a wide range of hardnesses and bead/shot size and shape.
Of course, really high density, fine-pitch traces may be quite difficult to do, but that's about the only real drawback I have been able to see so far. There are even mini-tabletop blasting chambers (or you can just do it outside if you feel like constantly buying new media).

Another cool possible benefit is to use it to drill! You would probably need to do the drill-blasting before the trace-blasting, and would need a drill stencil (I'm thinking a brass or nylon mask like a solder stencil but for the holes) and a jig to hold the nozzle perpendicular to the board. Adhere the stencil to the board (so the blast media doesn't creep between) then, using a fine hard grit, blast the holes. Then peel off the mask, use the photoresist as usual and blast the copper.

I'm sure it would be fun to try if nothing else. :)

~flight