Abstract: The present invention provides a tin-containing plating bath comprising: (a) a soluble stannous salt, or a mixture of a soluble stannous salt and at least one soluble salt selected from the group consisting of copper salts, bismuth salts, silver salts, indium salts, zinc salts, nickel salts, cobalt salts and antimony salts; and (b) at least one aliphatic sulfonic acid selected from the group consisting of alkanesulfonic acids and alkanolsulfonic acids, the aliphatic sulfonic acid being a purified aliphatic sulfonic acid in which the total amount of sulfur-containing compounds as impurities consisting of compound(s) containing one or more sulfur atoms with an oxidation number of +4 or less in the molecule and compound(s) containing one or more sulfur atoms and one or more chlorine atoms in the molecule is a minute amount or less. A tin or tin alloy plating film with excellent reflowability, film appearance, etc. can be formed by the use of this plating bath.

Abstract: There are provided a tin or tin-base alloy plating bath having significantly improved solderability, a tin salt solution and an acid or complexing agent solution for preparing or controlling and making up the plating bath, as well as electrical and electric components prepared by the use of the plating bath.

Abstract: The present invention provides a non-cyanide-type gold-tin alloy plating bath comprising: (i) at least one water-soluble gold compound, (ii) at least one completing agent for gold, (iii) at least one water-soluble tin compound, and (iv) at least one component selected from the group consisting of cationic macromolecular surfactants and cationic macromolecular compounds. By using the non-cyanide-type gold-tin alloy plating bath of the present invention, a gold-tin alloy plating film having good brightness, reflow properties and the like can be formed.

Abstract: The present invention provides a non-cyanide-type gold-tin alloy plating bath comprising : (i) at least one water-soluble gold compound, (ii) at least one completing agent for gold, (iii) at least one water-soluble tin compound, and (iv) at least one component selected from the group consisting of cationic macromolecular surfactants and cationic macromolecular compounds. By using the non- cyanide-type gold-tin alloy plating bath of the present invention, a gold-tin alloy plating film having good brightness, reflow properties and the like can be formed.

Abstract: The present invention provides a palladium-base electroless plating solution which is excellent in stability and which is capable of forming a satisfactory palladium-base deposit, the solution being an aqueous solution containing (a) a palladium compound, (b) at least one compound of ammonia and amine compounds, (c) an organic compound containing bivalent sulfur, and (d) at least one compound of hypophosphorous acid compounds and boron hydride compounds, and a palladium-base electroless plating solution containing a nickel compound in addition to said electroless plating solution.