today is Sep 28, 2022

We always enjoy [Thomas Sanladerer’s] 3D printing videos. But his latest isn’t only about 3D printing. He shows how he uses a DLP printer — which has UV light, after all — to expose PC board blanks with great results. Honestly, once we heard the idea, we immediately saw how that could work it is surprising more people aren’t taking advantage of their DLP printers like that. Of course, [Thomas] does his usual thorough treatment of the topic.

Really, this isn’t exactly 3D printing even though it uses a 3D printer. Exposing boards with UV light and artwork is an old process that has been around for years, usually using transparency film and a UV light source. With a printer, you can create artwork digitally and the UV light source is already there.

We liked his test strip method for dialing in the exposure time. Reminded us of our old darkroom days. He also tried using resin as a resist on a bare copper board but that didn’t seem to work as well as you would hope.

The first method, though, makes it painless to get the artwork on the PC board — even easier than laser toner transfer or direct laser exposing it. However, you still have to do the chemical steps and our least favorite part, drilling the holes. Maybe a good argument to stick with surface mount.

We love and respect the desire to do things for yourself and if you own a 3D printer, you probably do too. But unless you are in a big hurry, PCBs are cheap to have professionally done now (as we once predicted) and it really doesn’t make sense to create them at home, especially since it is hard to replicate plated holes, solder mask, and it is extra work to silkscreen the boards, too.

Still, if you need a quick-turn prototype or you just want the satisfaction of making your own PCB, don’t forget that your DLP printer is a ready-made UV exposure system.