| 摘要 |
PURPOSE:To obtain easily the titled laminated sheet for printed wiring board, which has excellent soldering heat resistance, etc., by using a solventless varnish contg. a resin component composed of two epoxy resins and a hardener composed of an org. polybasic acid anhydride. CONSTITUTION:A solventless varnish is prepd. by mixing a bisphenol A type epoxy resin (A) having an epoxy equivalent of 500 or below, a tri- or polyfunctional epoxy resin (B) having an epoxy equivalent of 300 or below (e.g. glycidyl ester of phenolic novolak), an org. polybasic acid amhydride (C) (e.g. hexahydrophthalic anhydride) and a curing accelerator (D) (e.g. 2-methyl- imidazole) as essential ingredients. A reinforcing substrate is impregnated with said varnish with heating at 40-100 deg.C and heated. The resulting B-staged prepregs are laminated and optionally, a metallic foil is laminated on the surface of the laminate to obtain the desired epoxy resin-laminated sheet. |
