| 摘要 |
PURPOSE: To smooth the surface of a multilayer printed wiring board and to control the wiring board in thickness independent of the residual rate of an inner copper foil by a method wherein thermosetting undercoat is applied onto an inner circuit board and turned into a B stage, then a copper foil possessed of a thermosetting insulating adhesive agent layer is laminated thereon, and the inner circuit board and the copper foil are formed into one piece by heating. CONSTITUTION: Liquid undercoat 3 is applied onto an inner circuit board 1 thick enough to cover an inner circuit 2 by a coating equipment such as a screen printing device. Thereafter, the liquid undercoat 3 is turned into a B stage by heating. Then, a copper foil 5 where thermosetting insulating adhesive agent 4 is applied is laminated on the undercoat 3 with a hard roll 6. By using the hard roll 6, the surface of a multilayer printed wiring board of this constitution is turned smooth, and an interlayer' thickness between the inner circuit 2 and the copper foil 5 is determined by only the thickness of the thermosetting insulating adhesive agent. Then, a concurrently integrating curing reaction is made to take place by heating to form the undercoat 3 and the thermosetting insulating adhesive agent 4 applied onto the copper foil 5 into one piece, and thus a multilayer printed wiring board 7 is manufactured. |
