SOLDER MASK COMPOSITIONS

摘要

A process for producing a solder mask comprises: 1) coating a printed wiring board with a solder mask composition comprising an aqueous solution of (1) an aryl cyclic sulfonium zwitterion monomer or (2) an aryl cyclic sulfonium zwitterion and a polymer containing two or more carboxyl groups; 2) exposing the coating to UV light in selected areas to polymerize the zwitterion monomer on the exposed areas; 3) developing the exposed coating with water or alkaline aqueous solution, and 4) curing the developed coating.