MANUFACTURE OF MULTILAYERED PRINTED WIRING BOARD

PURPOSE:To obtain a multilayered printed wiring board which is normal and has a flat surface by a method wherein a molding pressure is kept high at a prescribed point until a resin of a glass cloth basic material prepreg starts to be fluidized and then kept low at a prescribed point after the material is fluidized. CONSTITUTION:When a copper foil 3 is utilized, generation of wrinkle is made to decrease by increasing the molding pressure. But, when the molding pressure is increased, the deformation of an inner circuit board 4 takes place. Then, the molding pressure is kept high until resin of a glass cloth basic material prepreg 2 starts to fluidized (melting), then starts to decrease at the time when the resin starts to be fluidized, stops decreasing before a basic material 4 of an inner circuit substrate reaches at the point of Tg, and then is made to be the molding pressure. By these processes, a multilayered printed wiring board with a flat surface can be obtained which is excellent in a position accuracy.