A couple of boards has now been made with the latest prototype

A project log for PCB Exposer

PCB exposer using BluRay laser diode for exposing photosensitized PCBs (etch- and soldermask)

terje-ioTerje Io 12/24/2018 at 23:300 Comments

and I am happy with the results. I decided to try 0.2mm (8 mil) traces with a presensitized PCB for the latest and this is how it worked out:

The PCB size is 60x70mm, the IC pads are for a TSSOP-16 with 0.65mm pitch (and my drill bit is worn out...). It is just a "quick-and-dirty" prototype I am going to use for design verification. I will redo the design as a two layer board and send it off to a board house if I later decide to make a small run.