... I'm outline-milling my PCB's, but did light-curing and laser-engraving etch-resistant coatings previously.
A good methode is buying PCB's with photo-resist and cure it with a BluRay-UV-diodelaser or UV-LED with a focussed spot fine enough (and/or attached optical fiber).
With higher powered diodelasers (>100mW) you can coat clean copper with black paint and engrave the coating - then you'll etch the freed areas, also inverted to the UV-curing methode ...
A good methode is buying PCB's with photo-resist and cure it with a BluRay-UV-diodelaser or UV-LED with a focussed spot fine enough (and/or attached optical fiber).
With higher powered diodelasers (>100mW) you can coat clean copper with black paint and engrave the coating - then you'll etch the freed areas, also inverted to the UV-curing methode ...