Patent ID: 7363706
Filing Date: 2008-04-29
Classification: H05K,Y10T

Abstract:
1. A method of manufacturing a multilayer printed wiring board, comprising the steps of: preparing an insulating substrate, the front and back surfaces of which have a metal foil and forming a circuit by laminating a first insulating layer and the metal foil at least on one surface of the insulating substrate; forming a first nonthrough hole for a first interlayer connection in the at least one surface; forming a first barrier layer in the whole area of the at least one surface and the first nonthrough hole; forming a metal plating in the whole area of the first barrier layer; forming an etching resist in an interlayer connection via pad portion and an interlayer connection via bottom pad portion of an interlayer insulating layer of an upper layer; etching the metal plating thereby to remove an excess of the metal plating; exfoliating the etching resist; removing an exposed first barrier layer; forming a second insulating layer and a metal layer on the first insulating layer; forming a circuit; forming a second nonthrough hole for a second interlayer connection; forming a second barrier layer in the whole area of the circuit, the second nonthrough hole, and the second insulating layer; forming a metal plating in the whole area of the second barrier layer; forming an etching resist in an interlayer connection via pad portion for circuit formation in an outermost layer; removing an excess metal plating; exfoliating the etching resist; and removing the second barrier layer.