Method for electroplating with tin-zinc alloy

Abstract

The object of the present invention is to provide an electroplating method that enables the high-speed treatment of articles to be plated that was difficult to achieve with the conventional tin-zinc electroplating. The present invention provides a method for electroplating with a tin-zinc alloy that is performed under the following conditions: plating bath temperature 30 to 90° C., plating bath stirring rate 5 to 300 m/min, and cathode current density 5 to 200 A/dm 2 . Preferably, in the tin-zinc alloy plating bath, the divalent tin ion concentration is 1 to 100 g/L and the zinc ion concentration is 0.2 to 80 g/L.

1 . A method for electroplating with a tin-zinc alloy performed under the following conditions: 
 plating bath temperature: 30 to 90° C.;    plating bath stirring rate: 5 to 300 m/min; and    cathode current density: 5 to 200 A/dm 2 .    
   
   
       2 . The method according to  claim 1 , wherein the tin-zinc alloy plating bath comprises a hydroxycarboxylic acid or a salt thereof, and a pH of the tin-zinc alloy plating bath is 2 to 10.  
   
   
       3 . The method according to  claim 1 , wherein the tin-zinc alloy plating bath comprises at least one species selected from the group consisting of amphoteric surfactants and water-soluble compounds obtained by a reaction of an aliphatic amine, an organic acid ester, and a phthalic anhydride, and a pH of the tin-zinc alloy plating bath is 2 to 10.  
   
   
       4 . The method according to  claim 1 , wherein the tin-zinc alloy plating bath comprises at least one species selected from the group consisting of tertiary amine compounds and quaternary amine compounds, and a pH of the tin-zinc alloy plating bath is 10 to 14.  
   
   
       5 . The method according to  claim 1 , wherein the tin-zinc alloy plating bath comprises at least one species selected from the group consisting of nonionic surfactants, anionic surfactants, and cationic surfactants.  
   
   
       6 . The method according to  claim 1 , wherein in the tin-zinc alloy plating bath, the divalent tin ion concentration is 1 to 100 g/L and the zinc ion concentration is 0.2 to 80 g/L.