| 摘要 |
PCT No. PCT/JP80/00042 Sec. 371 Date Jan. 26, 1981 Sec. 102(e) Date Jan. 26, 1981 PCT Filed Mar. 13, 1980 PCT Pub. No. WO80/02632 PCT Pub. Date Nov. 27, 1980.A method of this invention for forming electrical wiring paths on an insulative substrate by means of an electroplating only at necessary portions on the insulative substrate comprises steps of forming on the insulative substrate a plated metal foundation layer which comprises an extremely thin conductive metal layer, closely fitting onto this extremely thin layer a first mask member from which the necessary portions for forming the electrical wiring paths are removed and having a surface to which no plating is applicable, forming a first plated layer of such metal as copper on the extremely thin conductive metal layer over the first mask member, closely fitting onto the first plated layer a second mask member from which some but not all portion of the electrical wiring paths of the first mask member are removed, forming a second plated layer of a second metal on the second mask member, and removing the first and second mask members and thus exposed portions of the extremely thin conductive metal layer, whereby the electrical wiring paths can be formed of a first metal only at the necessary portions on the insulative substrate, so that the amount to be used of such conductive first metal as copper can be reduced and it can be made possible to have a different second metal selectively plated on some but not all of such electrical wiring paths so as to improve environmental durability, to have the same first and second metal plated so as to improve the environmental durability, and to have the same first and second metal plated so as to increase the thickness of such electrical wiring paths and thereby increase the current flowing capacity.
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