Reducing electroless silver plating solution and reducing electroless silver plating method

Abstract

Provided are a reducing electroless silver plating solution and a reducing electroless silver plating method using the silver plating solution, the reducing electroless silver plating solution being capable of preventing decomposition of silver in the plating solution thereby to maintain stability of the solution and also being capable of preventing excessive roughening of an underlying metal or the like thereby to form a plating film having good film characteristics and a good appearance. The reducing electroless silver plating solution according to the present invention comprises a water-soluble silver salt and a reducing agent, wherein cyanide ions in a concentration of 0.006×10 −3 mol/L to 12.5×10 −3 mol/L are contained.

1 . A reducing electroless silver plating solution, comprising: a water-soluble silver salt and a reducing agent,
 wherein cyanide ions in a concentration of 0.006×10 −3  mol/L to 12.5×10 −3  mol/L are contained.   
     
     
         2 . The reducing electroless silver plating solution according to  claim 1 , wherein the above-mentioned water-soluble silver salt is a silver salt other than a cyanide, and the above-mentioned cyanide ions are contained as an alkali metal cyanide. 
     
     
         3 . The reducing electroless silver plating solution according to  claim 1 , wherein the above-mentioned reducing agent is at least one kind or more selected from hydroxylammonium sulfate and hydroxylacetate ammonium. 
     
     
         4 . The reducing electroless silver plating solution according to  claim 1 , having a pH of 8 to 11. 
     
     
         5 . A reducing electroless silver plating method, wherein, using the reducing electroless silver plating solution according to  claim 1 , electroless silver plating is applied to a plated material.