| abstract |
(57) [Abstract] [PROBLEMS] To provide a photosensitive resin composition capable of forming a flexible solder resist film and the like, a cured coating film thereof, and, for example, a flexible printed wiring board using the same. [Structure] Photosensitive prepolymer having a carboxyl group, Photosensitivity containing a photopolymerizable reactive diluent, a photopolymerization initiator, and a thermosetting component, and containing a reaction product of a novolac epoxy resin and a rubber-modified bisphenol A type epoxy resin in a photosensitive prepolymer. A resin composition, a cured coating film thereof, and a circuit board using the same. [Effect] The rubber component of the rubber-modified bisphenol A type epoxy resin exhibits flexibility, for example, in the solder resist film, and by adding a thermosetting component, the film improves various performances such as heat resistance and chemical resistance. In addition, by having a carboxyl group, the developability can be improved. And a circuit board with good reliability and productivity can be provided. |