Photosensitive resin composition, cured product, and electronic circuit board

The invention relates to a photosensitive resin composition, a cured product, and an electronic circuit board. Provided is a photosensitive resin composition which has good heat resistance and flexibility and can be easily removed by an alkali developer. A photosensitive resin composition containing (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) an epoxy compound, and (D) a reactive diluent, the (C) epoxy compound comprising (C-1) an epoxy compound having a structure represented by general formula (1) and (C-2) a crystalline epoxy compound, and the (D) reactive diluent comprising (D-1) a caprolactone-modified (meth) acrylate. 本发明涉及感光性树脂组合物、固化物和电子电路基板。提供：具有良好的耐热性和柔软性、且容易利用碱显影液进行去除的感光性树脂组合物。一种感光性树脂组合物，其包含：(A)含羧基的感光性树脂、(B)光聚合引发剂、(C)环氧化合物、和(D)反应性稀释剂，前述(C)环氧化合物包含：(C-1)具有下述通式(1)所示的结构的环氧化合物、和(C-2)结晶性环氧化合物，前述(D)反应性稀释剂包含(D-1)己内酯改性(甲基)丙烯酸酯。