CYAN-FREE GLOSS COPPER-TIN ALLOY PLATING BATH

PROBLEM TO BE SOLVED: To provide a gloss thick copper-tin alloy plating bath which does not contain a harmful cyan compound in a bath, enables a user to obtain an electroplating thick-film having a gloss appearance excellent in leveling property and smoothness and excellent in silvery white color from an aqueous solution of a neutral to weakly alkaline range by using a pyrophosphoric bath used heretofore and, further, enables a user to easily obtain a plated film having a gloss black appearance by specifying the metal concentration and the metal ratio. SOLUTION: An aldehyde amine-glycidyl ether reactant obtained by further allowing glycidyl ethers to react with a reactant (hereinafter, aldehyde amine type compound) of aldehydes and amines is used as additive in an aqueous solution in which a pyrophosphoric acid salt is contained as a main complexing agent, and a bivalent copper salt and a bivalent tin salt are dissolved in addition to the pyrophosphoric acid salt, and an aliphatic dicarboxylic acid or a salt of thereof is further contained in order to provide a gloss plated film having a preferable appearance free from burning or irregularity over a wide current density range. COPYRIGHT: (C)2011,JPO&INPIT