| abstract |
(57) [Problem] To significantly improve the flexibility of a cured film of a dilute alkali developing type solder photoresist ink composition containing a conventional photocurable resin and make it applicable to a flexible substrate, and further as a resist ink. Provided is a solder photoresist ink composition which is excellent in dilute alkali developability, solder heat resistance, and especially pressure cooker resistance, which are important performances. A compound having two or more hydroxyl groups and one or more carboxyl groups (a), a bifunctional or higher polyisocyanate having a six-membered ring structure (b), and a (meth) acrylate having a hydroxyl group (c) ), A carboxyl group-containing urethane acrylate (A), a polybasic anhydride-modified epoxy acrylate resin (B), a photopolymerization initiator (C), a difunctional or higher epoxy resin (D), and a diluent. A solder photoresist ink composition containing (E). |