| abstract |
The present invention provides a photocurable thermosetting resin composition, a dry film and a cured product thereof, which has a remarkably excellent insulation reliability and can form a cured film having important PCT resistance, HAST resistance, and electroless gold plating resistance as solder resists for semiconductor packages. And the printed wiring board in which hardened films, such as a soldering resist, are formed by these. The photocurable thermosetting resin composition which can be developed by the aqueous alkali solution contains carboxyl group-containing resin (except carboxyl group-containing resin which uses epoxy resin as a starting material), a photoinitiator, and an epoxidized polybutadiene. It is preferable that the said carboxyl group-containing resin does not contain a hydroxyl group, and it is more preferable to have a photosensitive group. |