Abstract: A non-cyanogen type electrolytic solution, for plating gold, contains a gold salt as a supply source of gold and is added with a non-cyanogen type compound wherein the electrolytic plating solution is added with one selected from a group of thiouracil; 2-aminoethanethiol; N-methylthiourea, 3-amino-5-mercapto-1,2,4-triazole; 4,6-dihydroxy-2-mercaptopyrimidine; and mercapto-nicotinate; as a compound forming a complexing compound with gold. Chloroaurate or gold sulfite is preferably used as a gold salt.

Abstract: A non-cyanogen type electrolytic solution, for plating gold, contains a gold salt as a supply source of gold and is added with a non-cyanogen type compound wherein the electrolytic plating solution is added with one selected from a group of thiouracil; 2-aminoethanethiol; N-methylthiourea, 3-amino-5-mercapto-1,2,4-triazole; 4,6-dihydroxy-2-mercaptopyrimidine; and mercapto-nicotinate; as a compound forming a complexing compound with gold. Chloroaurate or gold sulfite is preferably used as a gold salt.

Abstract: A wiring substrate with bumps protruding from a surface of the substrate covers one side of a metallic base with an electrical insulating film thereon, having open holes exposing the base, etching the base through the open holes to form concavities in the base, electroplating the interior faces of the concavities to form a barrier metal film thereon filling the concavities with a bump material by electroplating, and forming a barrler layer on the bump material in each concavity. A stack of wiring patterns is formed on the insulating film, adjacent wiring patterns being separated by a respective intervening insulating layer and being electrically connected to each other through vias in the intervening insulating layer, and to the bump material filled in the concavities. Thereafter, the base and barrier metal film are removed.

Abstract: A non-cyanogen type electrolytic solution, for plating gold, contains a gold salt as a supply source of gold and is added with a non-cyanogen type compound wherein the electrolytic plating solution is added with one selected from a group of thiouracil; 2-aminoethanethiol; N-methylthiourea, 3-amino-5-mercapto-1,2,4-triazole; 4,6-dihydroxy-2-mercaptopyrimidine; and mercapto-nicotinate; as a compound forming a complexing compound with gold. Chloroaurate or gold sulfite is preferably used as a gold salt.

Abstract: A method for producing a wiring substrate provided with bumps protruding from a surface of the substrate, the method comprising the steps of: covering one side of a metallic base with an electrical insulating film and forming open holes in the insulating film so as to expose at the bottoms thereof the base, etching the base using the insulating film having the open holes formed as a mask to form concavities in the base, electroplating the interior face of each of the concavities using the base as a plating power supply layer to form a barrier metal film on the interior face of each concavities, filling the concavities with a material for the bump by electroplating using the base as a plating power supply layer, forming a barrier layer on the surface of the material for the bump filled in each of the concavities using the base as a plating power supply layer, forming a stack of a predetermined number of wiring patterns on the insulating film, the adjacent wiring patterns in the stack being separated from each