PURPOSE: To prevent wires from breaking or shortcircuiting by providing as a core a metallic layer having corrosion resistance against an etching solution for copper, laminating metallic foil having a copper layer and a layer of resin impregnated in reinforced fiber on both sides of the core and uniting them in one body, heating the copper-clad laminate at the glass temperature of the resin or higher, and forming a circuit after that.
CONSTITUTION: A copper layer 1 is formed on a stainless board by electrolytic plating using a copper sulfate plating solution. Next, a nickel-phosphorus layer 2 is formed on the surface of the copper layer 1 by electrolytic plating using a Watt bath, and following this a copper layer 3 is formed by electrolytic plating using the copper sulfate plating solution. An insulating base material 4 composed of a plurality of sheets of glass cloth-epoxy applied cloth is put on the surface of the copper layer 3 of metallic foil obtained in this way, and a laminate is formed by heating. Consequently, it becomes possible to heat the resin laminate with metallic foil at the glass transition temperature of the resin or higher, preventing the attaching of the resin, etc., to circuit conductors, and it becomes possible to ensure high dimensional precision. Besides, it becomes possible to reduce the numbers of the breakings and the shortcircuits of conductor patterns and increase the yield.
NAKASO AKISHI
TSUYAMA KOICHI
URASAKI NAOYUKI
HASEGAWA KIYOSHI
