Patent ID: 8337655

Claim:
A method of producing a multi-layer printed wiring board, comprising: (a) conveying an adhesive sheet from an adhesive sheet roll, wherein said adhesive sheet comprises a prepreg formed on a support film and said adhesive sheet is wound in a roll, and placing said adhesive sheet such that a surface of said prepreg contacts one or both of the surfaces of a circuit board; (b) partially adhering said adhesive sheet to said circuit board by heating and pressing a part of said adhesive sheet from the support film side, and cutting said adhesive sheet according to the size of said circuit board with a cutter, to obtain a temporarily fitted adhesive sheet; (c) heating and pressing said temporarily fitted adhesive sheet under reduced pressure to laminate said adhesive sheet on said circuit board; (d) thermally curing said prepreg, to obtain an insulating layer; and (e) detaching said support film after said thermally curing, wherein, in said adhesive sheet, said support film has a release layer on the surface side in contact with said prepreg, and the peel strength of said support film from said prepreg before thermal curing is not less than 1.5 gf/50 mm at 180-degree peel strength, wherein said method further comprises drilling said insulating layer, roughening said insulating layer, to obtain a roughened insulating layer surface, forming a conductive layer on said roughened insulating layer surface by plating, and forming a circuit on said conductive layer, and wherein said drilling is performed between said thermally curing said prepreg and said detaching said support film.