Method of producing multilayer printed wiring board and multilayer printed wiring board

摘要

To provide a method of producing a multilayer printed wiring board that can be intended to have low-profile, light-weight and high-density wiring of a printed wiring board, and a multilayer printed wiring board produced by the method of producing a multilayer printed wiring board, the double-sided substrate is produced by the steps of forming an insulating resin layer (2) on a metal foil (1); of forming a via hole (3) in the insulating resin layer (2); of forming a first circuit pattern (4) on the insulating resin layer (2) and forming a conductive layer (5) in the via hole (3), by plating; and of etching the metal foil (1) to form it into a second circuit pattern (6). The produced double-sided substrate (7) is used as a core substrate for producing multilayer printed wiring board by a laminate-en-bloc or a build-up method.