HIGH DENSITY PRINTED BOARD AND MANUFACTURE THEREOF

PURPOSE:To enhance a conductive layer in reliability so as to obtain a high resolution fine wire parameter by a method wherein a copper plating layer is provided onto a metal plating base layer provided to the inner wall of a through-hole high in resistance to copper etching solution to cover the land of a circuit pattern. CONSTITUTION:A nickel plating 4 having a thickness of 1mum is formed as a base layer on the inner wall of a through-hole 2, and a copper plating 7 is provided thereon to constitute a coating of dual structure. A land 9a of a copper foil circuit parameter 9 on the surface of a board is coated with a copper plating 7 formed into one piece together with the copper plating 7 inside the through-hole 2, and a solder resist 6 is formed to cover all the surface of the board including the surface circuit parameter 9 except the inside of the through- hole 2 and the land 9a. As mentioned above, a metal plating of nickel or the like excellent in resistance to copper etching solution and in adhesion to the copper plating 9 is provided under the copper plating 9 as a base layer, so that the copper plating 7 can be enhanced in peeling strength and prevented from bulging inside a through-hole. As a result, the inside of a through-hole can be enhanced in reliability.