| abstract |
(57) [Summary] [Problem] To minimize the α dose affecting semiconductor elements, and to achieve heat resistance, adhesion, weather resistance, electroless plating resistance, electrical characteristics, PCT required for solder resists for IC packages. Provided is a photo-curable / thermo-curable resin composition capable of obtaining a cured film having excellent properties such as resistance and the like, and a cured film thereof. SOLUTION: The photo-curable / thermo-curable resin composition comprises: (A) a high-purity synthetic silica powder having a uranium content of 1.0 ppb or less, (B) a carboxyl group and at least two ethylenically unsaturated bonds in one molecule, and a solid content acid value of 50 to 150 mg KOH. / G of photosensitive prepolymer, (C) photosensitive (meth) acrylate compound, (D) It contains a photopolymerization initiator, (E) an epoxy resin, and (F) a curing catalyst. The composition is applied to a substrate, dried, exposed and developed, and then finish-cured by irradiation with active energy rays and / or heat to obtain a cured film having a sufficiently small α-dose. |