Patent ID: 7780836

Claim:
A method for fabricating a multilayer wiring board, comprising: preparing a conductive layer forming material comprising a film-shaped reinforcing material and a separable thin film type conductive layer formed on the film-shaped reinforcing material; transcribing the thin film type conductive layer from the conductive layer forming material to both surfaces of a lengthy electric insulating material to form a surface conductive layer and a back surface conductive layer; providing a via hole penetrating through the surface conductive layer and the electric insulating material; forming a pattern composed of a photosensitive plating resist film with a desired shape at a predetermined position on the surface conductive layer and the back surface conductive layer; performing an electrolytic deposition using the back surface conductive layer as a cathode to fill the via hole with an electroplating metal and to form a surface wiring layer and a back surface wiring layer respectively at a space in the pattern of the photosensitive plating resist film; and removing the photosensitive resist film as well as the surface conductive layer and the back surface conductive layer provided under the photosensitive resist film to form a conductive wiring pattern comprising the surface wiring layer and the back surface wiring layer.