Method and composition for applying coatings on printed circuit boards

摘要

A coating is produced by a method including a screen printing of a photopolymerizable composition on a printed circuit board, illuminating said composition to partially polymerize it and bake it to complete the polymerization. The composition used by said method contains a reaction product of a monoethylenically unsaturated carboxylic acid with a material of the group of epoxy resin and epoxidized novolak, a phenoxy resin, a thickening agent, a polyethylenically unsaturated compound, a photo-initiator and a solvent. The coating produced according to this invention is used as solder mask.