Patent ID: 7584535

Claim:
A method of manufacturing a multi-layer circuit wiring board, said method comprising: forming a first via-contact hole in a first film having a first conductor layer formed on one surface thereof and a second conductor layer formed on another surface thereof, by using a laser beam, said first via-contact hole passing through the first conductor layer and first film and not passing through the second conductor layer; performing an electrolytic plating to bury the first via-contact hole with a metal thus forming a first via-contact layer electrically connecting said first conductor layer with said second conductor layer; forming a first wiring pattern in said first conductor layer, and forming a second wiring pattern in said second conductor layer; laminating a second film having a first insulating layer and a third conductor layer formed on said first insulating layer on said one surface of said first film in such a manner that said first insulating layer is in contact with said one surface of said first film, after that or simultaneously laminating a third film having a second insulating layer and a fourth conductor layer formed on said second insulating layer on the other surface of said first film in such a manner that said second insulating layer is in contact with said other surface of said first film; forming a second via-contact hole in said second film, by using a laser beam, said second via-contact hole passing through the third conductor layer and first insulating film and reaching the first wiring pattern; forming a third via-contact hole in a third film, by using a laser beam, said third via-contact hole passing through the fourth conductor layer and second insulating film and reaching the second wiring pattern; performing an electrolytic plating to bury the second via-contact hole and third via-contact hole with a metal thus forming a second via-contact layer electrically connecting said first wiring pattern with said third conductor layer, and third via-contact layer electrically connecting said second wiring pattern with said fourth conductor layer; forming a third wiring pattern for mounting an IC on said third conductor layer; and forming a fourth wiring pattern to be electrically connected with a printed wiring board on said fourth conductor layer.