| 摘要 |
PURPOSE:To improve the pattern reliability of a multilayered printed wiring board by integrally arranging outer layer members after positioning the outer layer members to the upper and/or lower surfaces of a required number of inner layer members with resin layers in between and melting and hardening the resin layers at desired positions by ultrasonic welding. CONSTITUTION:After circuits are formed by etching on both surfaces of an epoxy-resin laminated board, the substrate of which is made of double-sided copper-clad glass fabric and which has a 1-mm thickness, the laminated board us dipped in a blackening liquid composed of sodium chlorite, sodium hydroxide, and trisodium phosphate and maintained at 90 deg.C for 10 seconds. Then, after the laminated board is successively dipped in a sodium hydroxide liquid maintained at 30 deg.C for 10 seconds and an amine Volan(R) liquid maintained at 60 deg.C for 50 seconds and dried at 100 deg.C for 30 minutes, two pieces of epoxy-resin glass prepreg having a thickness of 0.1mm are arranged on and positioned to each of the upper and lower surfaces of three inner layer members and the resin layer is melted and hardened at its four corners by ultrasonic welding. Thereafter, an 8-layer printed wiring board is obtained by coating the laminated body with copper foil having a thickness of 0.035mm and laminate-molding the laminated body for 120 minutes at 170 deg.C under a molding pressure of 40kg/cm. |
