METHOD OF APPLYING A SOLDER STOP COATING ON PRINTED CIRCUIT BOARDS

摘要

A solder-stop resist (5) and a positive-working photoresist (6) are applied in succession over the entire surface of the printed circuit board, after which the photoresist (6) is selectively exposed, preferably with the aid of laser radiation (Ls), in the region of the plated-through holes (3) and/or solder pads (4) and developed. The solder-resist (5) in the regions not protected by the photoresist (6), i.e. in the regions of the plated-through holes (3) and/or solder pads (4), is then stripped and, as a final step, the remaining photoresist (6) is also stripped. The method according to the invention is suitable, in particular, for the application of a solder-stop coating to three-dimensional printed circuit boards since in this case conventional masking techniques cannot be used for structuring the solder-resist. ……