| 摘要 |
PROBLEM TO BE SOLVED: To provide a photosensitive resin varnish having high reliability and photosensitivity and developable with little resin residue and to provide a photosensitive adhesive film and a printed wiring board using the film. SOLUTION: The photosensitive resin varnish contains a photo cationic polymerization initiator with tetrakispentafluorophenyl borate as an anionic species and tolylcumenyl iodonium as a cationic species, a bisphenol type epoxy novolak resin which is solid at ordinary temperature, a bisphenol type epoxy novolak resin which is liquid at ordinary temperature and methyl ethyl ketone as a solvent. The photosensitive adhesive film is obtained by volatilizing the solvent from the photosensitive resin varnish. Insulating resin build-up layers 4, 14, 6, 16 and resin soldering resist layers 8, 18 obtained by curing the photosensitive adhesive film are very high reliability layers having high moisture absorption resistance and adhesion. |
