| abstract |
A solder resist having both adequate sensitivity at photo-irradiation and alkali developability, and the solder resist forming a cured product which is excellent in dimensional stability against temperature change, does not exhibit brittleness, and further, is excellent in water resistance, electrical insulation, thermal cycle test resistance (TCT resistance) and the like is provided, and further, a dry film having a solder resist layer, a cured product and a printed wiring board are provided. The solder resist comprising an acid-modified vinyl ester synthesized from an epoxy compound, a phenol compound, an unsaturated monobasic acid and a polybasic acid anhydride, wherein the epoxy compound contains a crystalline epoxy resin having a melting point of 90° C. or more, and the phenol compound contains a compound having a bisphenol S structure. |