METHOD FOR MANUFACTURING PRINTED WIRING BOARD AND COPPER FOIL FOR LASER PROCESSING

摘要

An objective of the present invention is to provide a method for manufacturing a printed wiring board that has fewer manufacturing steps, has superior laser processing properties, and can satisfactorily form a wire pattern; and a copper foil for laser processing and a copper clad laminate. To achieve this objective, the method for manufacturing a printed wiring board according to the present invention is a method in which via holes for interlayer connections are formed by directly irradiating infrared laser light onto a readily-meltable laser absorption layer of a laminated body. In the laminated body, copper foil for laser processing provided on the surface thereof with the readily-meltable laser absorption layer which absorbs infrared laser light and has a faster etching rate with respect to copper etching fluid than the copper foil, and another conductive layer, are laminated with the interposition of an insulating layer. The readily-meltable laser absorption layer is removed from the surface of the copper foil in a desmearing step for removing smears in the via holes and/or a micro-etching process which serves as a pretreatment for an electroless plating step.