PROCESS FOR FORMING SOLDER RESIST FILM

摘要

A method for forming a solder resist film is provided to improve surface curing characteristics and to enhance the term of validity of a solder resist ink by controlling the injection period of a surface photoinitiator. A method for forming a solder resist film comprises the steps of preparing a solder resist ink base comprising a base resin, a pigment, a filler and a first surface photoinitiator, and a solder resist ink auxiliary comprising a base resin and a filler; mixing the base, the auxiliary and a second surface photoinitiator to obtain a solder resist ink composition; coating the solder resist ink composition on the surface of a printed circuit board; and irradiating UV rays to cure the solder resist ink composition completely.