| 摘要 |
PURPOSE:To eliminate copper wrinkle and to improve surface smoothness and dimensional stability by forming a multilayer printed circuit board of a mold plate made of a material having a linear expansion coefficient equal to or more than that of the copper foil of its outer layer. CONSTITUTION:Two prepregs 5 formed by impregnating a glass base material with epoxy resin mixed with curing agent and drying it are interposed between a copper foil 4 having 16.7X10<-6> of linear expansion coefficient as an outer layer copper foil and an inner layer circuit board 6 formed in advance with a conductor pattern to be laminated, and interposed between stainless steel mold plates 3 having, for example, a linear expansion coefficient larger than that of the copper foil as a laminate. A plurality of the laminates are superposed, and inserted between hot boards 1 each having a cushion material 2. It is hot pressure molded to manufacture a multilayer printed circuit board. Thus, the board having less wrinkles, warpage, twist and dimensional change, excellent thickness accuracy and surface smoothness can be stably and efficiently manufactured. |
