Making PCBs with a laser-engraved mask

I saw this video on YT where this guy was making PCBs by laser-engraving copper clad boards coated in black spray paint, and then doing traditional chemical etching. Has anybody tried this with the Snapmaker 1.6W laser module? It looks like a good alternative to CNC carving.

I want to try to use my 200mW laser to expose the photo sensitive layer of the PCB and then develop and etch the PCB.

My goal is to create boards using the least expensive materials possible and with the least amount of special handling. Those photo sensitive boards violate both and you may have issues with the wavelength of the 200mW laser.

The 200mW 405nm laser is perfect for the photosensitive ones. Professional ones use a 120mW 405nm UV laser (Bungard LaserPro 3000). I already made some with it (see pics below). The method with spray paint (or Edding) could work with the 200mW (I use this method for engraving acrylic plates).

For the software I would suggest using Eagle + “PCB-Gcode” UDP. I already modified my gcodes-defaults.h that it will work without any post-processing in an editor. If you want I can share it with you. Just all drill holes will just have this small holes, because I just unfocus the laser for +1mm.

I also wanna try the dry film resist method wich big Clive is using ( )
It should be much cheaper then the usual ones and you can develop them with washing soda.

developed PCB:

etched PCB:

same layout but with SnapmakerJS and 10 lines/mm (all wiggly wobbly :laughing: )