Patent ID: 8083922

Claim:
A tin electrolytic plating solution for electronic parts, comprising: (a) a soluble stannous salt; (b) an acid or a salt thereof; (c) at least one kind of complexing agent selected from an oxycarboxylic acid, a polycarboxylic acid, a monocarboxylic acid, and a salt thereof; (d) an antioxidant for Sn 2+ ; a nonionic surfactant represented by General Formula (I) where R represents H or CH 3 , iso-C n H 2n+1 represents a branched alkyl group where n is 8 to 13, and m is 7 to 50; an alkyl imidazole represented by General Formula (II) where R 1 represents a hydrogen atom or an alkyl group having a carbon number of 1 to 3, and R 2 represents an alkyl group having a carbon number of 8 to 16; and a cationic surfactant represented by General Formula (III) where R represents an alkyl group having a carbon number of 8 to 14, and X − represents a halogen ion or an anion.