We have PCB design where we use pads without holes, just as copper artifact - the reason is that we need exact size and location/coordinates to maintain plus some other geometrical considerations. Bottom line is that design is done, everything looks exactly as we need, but areas where these pads are turn out as exposed copper areas (as it supposed to be). Question that I have is the following - is it ANY way I can explicitly cover pad with solder mask such as it will not show as exposed copper? (our pads are not multi-layer and do not have any holes). I saw similar question posted in 2015, but answer was not clear.
Any advice or instructions how one can accomplish it?
Thanks a bunch for helping!