Patent ID: 8006377

Claim:
A method of manufacturing a printed wiring board comprising: forming a seed layer comprising metal over a lower resin insulation layer; forming a plating resist on the seed layer such that a first portion of the seed layer is covered by the plating resist and a second portion of the seed layer is not covered by the plating resist; subjecting the seed layer and the plating resist to an electrolytic plating process so as to form an electrolytic plated film on the second portion of the seed layer; removing the plating resist from the first portion of the seed layer; removing the first portion of the seed layer to form a conductor circuit comprising the seed layer and the electrolytic plated film over the lower resin insulation layer, wherein said conductor circuit is formed to have a flat surface; forming a metal layer on an entire surface of the conductor circuit, the metal layer comprising Sn in order to improve adhesion of the metal layer to a resin material; and forming an upper resin insulation layer over the conductor circuit and the metal layer comprising Sn such that the upper resin insulating layer has improved adhesion to the conductor circuit.