| abstract |
Photo-curing that has good workability, does not cause handling cracks, has high sensitivity, and can obtain high reliability when used in a cured product such as a printed wiring board or a semiconductor package. The resin composition, its dry film and cured product, and a printed wiring board using them are provided. A photocurable resin composition that can be developed with an alkaline solution contains a carboxyl group-containing photosensitive resin, a photopolymerization initiator, a filler, and an elastomer, and the content of the filler is the total amount of nonvolatile components in the composition. The content ratio of the elastomer is in the range of filler: elastomer = 90: 10 to 70:30 (mass ratio). [Selection figure] None |