Patent ID: 7618766

Claim:
A photosensitive circuit coverlay composition consisting essentially of: a. an unsaturated phosphorus-containing monomer said monomer being a mono-functional or multi-functional methacrylate or acrylate being present in an amount between and including 20 and 70 weight percent of the total composition, b. a phosphorus containing photo-initiator present in an amount between and including 2 and 18 weight percent of the total composition, c. a polymer binder having an unsaturated bond, a carboxylic acid group, or a hydroxyl group, and d. a blocked isocyanate or blocked polyisocyanate thermal crossliniking agent, wherein the total composition has a halogen content of less than 100 parts per million based upon weight and has a phosphorus content in an amount between, and including 2.0, and 6.0 weight percent.