Photo-cured heat-cured resin composition and printed circuit board produced with the same

A light-curing thermo-curing resin composition and a printed circuit board obtained using the same are provided, the composition has high light sensitivity and excellent curing depth in ultraviolet ray and laser exposure, thus further having great developing ability to pass through diluted alkaline aqueous solution while being excellent in storage stability and operability, so the composition is suitable for solder resisting agent. The light-curing thermo-curing resin composition comprises (A) carboxyl-containing resin, (B) mercaptobutyric acid or derivatives thereof, (C) photopolymerization initiator, (D) compounds having 2 or more of olefinic unsaturated groups in the molecules, and (E) thermo-curing components. The suitable (A) carboxyl-containing resin is preferably the carboxyl-containing resin capable of free radical polymerization and having unsaturated double bond. In addition, the (C) photopolymerization initiator is preferably oximes photopolymerization initiator (C1), particularly preferably proxet