| 摘要 |
PURPOSE:To prevent brown discolored spot of roughly a circular shape, which is generated in the junction surface between an internal copper layer on the peripheral part of a through hole and a resin layer on a board, in a multilayer printed circuit board, and to improve the adhesion of the junction surface. CONSTITUTION:A copper oxide layer having small recesses and projections is formed on the surface of a copper by a method of bringing the copper surface into contact with an aqueous solution containing an oxidizing agent or a method of performing an anodizing treatment of the copper surface using an alkaline electrolyte, then, the copper oxide layer is brought into contact with a reducing agent to reduce it to a metal copper layer. After the copper oxide layer is reduced to the metal copper layer, the metal copper layer is brought into contact with an aqueous solution containing one of a folmaldehyde and a complexing agent consisting of dihydric copper or the both and thereafter, is rinsed and dried. |
