| 摘要 |
PURPOSE: To prevent the generation of voids at the time of molding and a resin crack or ply separation at the time of soldering by using a prepreg prepared by impregnating a glass base material with an epoxy resin compsn. so that the resin impregnation amt. of the peripheral part thereof is made less than that of the central part thereof. CONSTITUTION: A prepreg prepared by impregnating a glass base material with an epoxy resin compsn. so that the resin impregnation amt. of the peripheral part thereof is made less than that of the central part thereof is used. As the glass base material, one generally used for a laminated sheet may be used. The epoxy resin compsn. consists of an epoxy resin, a curing agent and a curing accelerator. As the epoxy resin, a system prepared by mixing a novolac epoxy resin with a bisphenol A type epoxy resin or a bromine compd. thereof is pref. and the curing agent is composed of an amine curing agent and the curing accelerator is composed of an imidazole derivative. The resin impregnation amt. of the peripheral part of the prepreg is made less than that of the central part thereof by 2-10wt.%. |
