Patent ID: 7495332

Claim:
A multilayer printed wiring board comprising: a core board; a build-up layer that is formed on the core board and has a conductor pattern formed on the upper surface thereof; a resin layer comprising a hardened film formed on the build-up layer and formed by hardening a resin composition comprising an epoxy resin, a phenol resin, cross-linked rubber particles and a hardening catalyst; a mounting electrode for mounting an electrical part provided on the upper surface of the resin layer; and a conductor post penetrating through the resin layer for electrically connecting the mounting electrode to the conductor pattern, wherein the resin composition comprises 5 to 100 parts by weight of the phenol resin, 5 to 200 parts by weight of the cross-linked rubber particles and 0.1 to 20 parts by weight of the hardening catalyst with respect to 100 parts by weight of the epoxy resin, the cross-linked rubber particles have a glass-transition temperature in a range between −80° C. to −20° C., and the resin composition has a glass-transition temperature in a range between 100° C. to 200° C.