PURPOSE: To obtain a wiring board having excellent fine wiring forming characteristic by plating a thin layer of nickel which is closely placed in contact on a substrate with a conductive metal and improving a bonding force between a conductive metal and nickel thin layer.
CONSTITUTION: When a nickel layer is formed on the surface of a metal foil supporting material such as a copper foil having the fine projected and recessed rough surface by the non-electrolytic nickel plating, a layer has the uniform thickness long the rough surface of the supporting material. After laminating a resin, a nickel thin layer is also transferred, simultaneously with formation of the projected and recessed shapes of the metal foil supporting material, to the surface of substrate from which only the supporting material is etched. In the successive processes, this nickel thin layer plays a role of (l) catalyst core for non electrolytic plating and (2) base metal layer for electric plating, and moreover the close contact area between a metal layer formed by the plating and resin gives a strength enough for the close contact force during lamination under the heated and pressurized condition. Therefore, a printed wiring board having a large bonding force for the plated metal can be obtained by forming a circuit through the plating of a metal layer up to the desired thickness on the nickel thin layer.
NAKASO AKISHI
HASEGAWA HIROSHI
OKAMURA TOSHIRO
HIROYAMA YUKIHISA
IKEDA MASAYOSHI
