| abstract |
(57) [Summary] [PROBLEMS] To provide a high photocuring depth at the time of exposure, high resolution, excellent heat resistance, chemical resistance, electrical properties, moisture absorption, P Provided is a photocurable / thermosetting resin composition of an alkali development type which provides a cured product having CT resistance and does not generate mist in various steps involving heating. The composition comprises (A) a photosensitive prepolymer having two or more unsaturated double bonds and one or more carboxyl groups in one molecule, and (B) at least one kind as a photopolymerization initiator. Α-aminoacetophenone-based compound of (B ′) a photopolymerization initiator other than the above photopolymerization initiator, It contains (C) a reactive diluent and (D) an epoxy compound having two or more epoxy groups in one molecule. Such a photocurable / thermosetting resin composition is flexible, BG It is suitably used as a solder resist for A, CSP, and printed wiring boards for high definition, and as an interlayer resin insulating layer of a multilayer printed wiring board. |