PRODUCTION OF MULTILAYERED COPPER CLAD LAMINATED SHEET

摘要

PURPOSE:To obtain a multilayered copper clad laminated sheet reduced in the dimensional change at the time of the processing of a multilayered printed wiring board by superposing an inner printed circuit board and outer boards or copper foils one upon another through prepregs to heat and press them and subsequently subjecting the whole to heat treatment within a predetermined temp. range. CONSTITUTION:Heat treatment is performed within the temp. range of the molding temp. + or -20 deg.C at the time of the molding of a multilayered copper clad laminated sheet under heating and pressure. For example, a glass base material and epoxy resin double-sided copper clad laminated sheet is subjected to circuit processing and oxidation treatment to obtain an inner circuit base material 1. Prepregs 2 impregnated with varnish based on the same epoxy resin as the inner circuit base material 1 and copper foils 3 are arranged to both surfaces of the inner circuit base material in this order and the whole is molded while heated and pressed at 170 deg.C for 90 min under vacuum and cooled as it is. The obtained four-layered board is heat-treated at 150-190 deg.C for 10-120min. By this method, a multilayered printed wiring board generating no discoloration and extremely reduced in the dimensional change due to the processing of a multilayered wiring board in a post-process can be obtained.