Using a Laser to CREATE (not etch) PCB traces on plastic

[Brumby]

Intriguing.  Does anyone have any experience with this sort of thing?

[MagicSmoker]

Applied Science is a great channel and I watched that video recently. None of it seemed quite practical enough for making pcbs at home, but it was very interesting nonetheless.

I watched that video because of another one on Marco Rep's channel* where he used a cheap laser engraver to do "isolation milling" on pcbs first painted black. The premise looked reasonable and these engravers are only $200 from the usual sources (Banggood, Gearbest, Amazon, etc.) so I bought one to try out and while I intend on writing a more comprehensive post about my experience soon, for now I will just say that after much tweaking and hair-pulling I got surprisingly good results out of it. It can't compete on accuracy and trace/space fineness with the traditional home photolithography process (exposing boards pre-sensitized with positive photoresist through artwork laser printed on a transparency), but the per-board cost is much, much lower (like, $1 for a 100mm x 150mm board, vs. $6.5 to $10).


Marco Rep video on laser engraving a pcb:

[MagicSmoker]

any pics of your good or even bad takes?

Yeah, I'll post a couple here. I used the latest version of LaserGRBL to control the engraver and to do raster-to-gcode conversion. Raster mode produces terrible quality output, though (much as Marco Rep found out) so I finally tried FlatCAM and got excellent results on the 2nd attempt with its vectorized gcode output. Oh, and the rasterized board took >8 hours to burn while the vectorized one took 15 minutes. I still need to figure out how to get FlatCAM to remove all the leftover copper "islands" that are a consequence of vector mode operation. EDIT - and also how to merge the excellon drill file so it matches up with the board, a problem acknowledged by the FlatCAM documentation, but without a clear explanation of what steps should be done in the software, specifically, to fix it.