Abstract: A solder 14 is formed, by a plating method, on a connecting surface 21A and a side surface 21B in a connecting pad 21 of a wiring board 11 which is opposed to a metal bump 13 formed on an electrode pad 31 of a semiconductor chip 12, and subsequently, the solder 14 is molten to form an accumulated solder 15 taking a convex shape on the connecting surface 21A of the connecting pad 21 and the metal bump 13 is then mounted on the connecting surface 21A of the connecting pad 21 on which the accumulated solder is formed, and the accumulated solder 15 and the metal bump 13 are thus bonded to each other.

Abstract: The present invention provides a non-cyanide electroless gold plating solution free from a cyanide compound, comprising, as a completing agent of gold, a compound represented by the formula shown below or a salt thereof: X—(CH2)n—SH wherein n is 2 or 3 and X is SO3H or NH2, and having a pH value of 7 or less. The invention also provides a process for electroless gold plating using the non-cyanide electroless gold plating solution.

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: The present invention provides a non-cyanide electroless gold plating solution free from a cyanide compound, comprising, as a completing agent of gold, a compound represented by the formula shown below or a salt thereof: X—(CH2)n—SH wherein n is 2 or 3 and X is SO3H or NH2, and having a pH value of 7 or less. The invention also provides a process for electroless gold plating using the non-cyanide electroless gold plating solution.

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