| 摘要 |
PURPOSE:To improve soldering resistance and separation resistance by employing, as an adhesive among a polyimide film, metal foil, and a metal sheet, one including particular epoxy resin and bisphenol A type epoxy resin in a specific ratio. CONSTITUTION:A metal base board includes a polyimide film insulating layer bonded thereto by an adhesive between a circuit formation conductive metal foil and a base metal sheet. In the metal base board, the adhesive comprises epoxy resin A yielded by a reaction between novolac type epoxy resin bisphenol A type epoxy resin of 180-200 epoxy equivalent, bisphenol A type epoxy resin B of 900-2100 epoxy equivalent, a hardener C, and a promotor D. An epoxy resin composition of a ratio of 30-80 wt.pts. A component and 70-20 wt.pts. B component is employed. Hereby, soldering resistance and separation resistance can be improved. |
