Method for reproducing plating solution

Abstract

A plating solution containing a leveler is brought into contact with silica particles with an average particle diameter of 500 μm or less to remove impurities from the plating solution.

1 . A method for reproducing a plating solution comprising:
 bringing a plating solution containing a leveler into contact with silica particles with an average particle diameter of 500 μm or less to remove impurities from the plating solution.   
     
     
         2 . The method of  claim 1 , wherein the plating solution is circulated from a plating tank containing the plating solution and the plating solution from which the impurities are removed by the circulation is returned to the plating tank. 
     
     
         3 . The method of  claim 1 , wherein the silica particles are contained in an impurity removing device disposed in a circulating path for the plating solution. 
     
     
         4 . The method of  claim 3 , wherein the impurity removing device is a bag filter. 
     
     
         5 . The method of  claim 4 , wherein an average particle diameter of the silica particles is larger than an opening of the bag filter. 
     
     
         6 . The method of  claim 1 , wherein the plating solution is an electrolytic tin plating solution or an electrolytic tin alloy plating solution. 
     
     
         7 . The method of  claim 1 , wherein the leveler is indole.