Is the UV curable paint used for PCB etching the same UV curable paint used for making PCB solder masks? Some have different eBay descriptions but they're all in identical 100g black containers.
As far as I can tell, the only difference to making a solder mask is only doing the first development with sodium carbonate to remove the unexposed UV paint and then leaving the rest? (i.e. no ferric chloride / ammonium persulphate or sodium hydroxide)
Can I do multiple layers of solder masks? Can I use a second white solder mask over the top of the first green solder mask in place of silk screening to add the legend on?
Best Answer
Etch resist used in PCB manufacturing is typically a photosensitive film laminated to the board. It's called dry film photoresist. here is a typical product datasheet showing all the processes.
Note the stripping process at the end- using caustics. It's almost impossible to remove solder mask after it cross-links, so I don't think it would be very suitable.