Steven A. Castaldi - Torrington CT
Peter D. Gabriele - Bristol CT
Victor Saverino - Southington CT
MacDermid, Incorporated - Waterbury CT
A photosensitive composition for providing a solder mask on a printed circuit board is described, comprised of (a) an esterified styrene-maleic anhydride copolymer having less than 15%, most preferably less than 5%, free anhydride, with at least about 50% of the available anhydride groups being esterified with a hydroxyalkyl (meth)acrylate and at least about 0. 1% of the available anhydride groups being esterified with a monohydric alcohol; (b) a multifunctional (meth)acrylate monomer; and (c) a multifunctional epoxide. The composition is coated on a printed circuit board, imagewise exposed to radiation to effect sufficient curing of the composition at exposed areas to enable removal of unexposed areas with developer, and post-baked after development to produce a desired patterned distribution of the cured composition to serve as a solder mask.