Electroplating contacts with silver-alloys in a basic bath

Abstract

A method for silver-alloy plating an electrical contact and a silver-alloy plated electrical contact are provided. The method includes cleaning the electrical contact by removing contaminates and exposing the electrical contact to at least one of an acid or base. The method includes preparing a sliver-alloy plating bath including water, a silver complex, and a metal complex, the metal complex being at least one of nickel or cobalt. The method includes silver-alloy plating the electrical contact in the silver-alloy plating bath, wherein the plating bath has a pH of greater than 7. The metal complex forms about 0.3% to about 50% by weight of a content of a silver-alloy plated deposit.

What is claimed is: 
     
         1 . A method for silver-alloy plating an electrical contact comprising:
 cleaning the electrical contact by removing contaminates and exposing the electrical contact to at least one of an acid or base;   preparing a sliver-alloy plating bath including water, a silver complex, and a metal complex, the metal complex being at least one of nickel or cobalt; and   silver-alloy plating the electrical contact in the silver-alloy plating bath, wherein the plating bath has a pH of greater than 7.   
     
     
         2 . The method of  claim 1 , wherein the pH of the plating bath is about 7 to about 11. 
     
     
         3 . The method of  claim 1 , wherein the metal complex is nickel citrate-ammonia. 
     
     
         4 . The method of  claim 1 , wherein the metal complex is cobalt citrate-ammonia. 
     
     
         5 . The method of  claim 1 , wherein the silver complex is silver thiosulfate. 
     
     
         6 . The method of  claim 1 , wherein the silver complex is silver succinimide. 
     
     
         7 . The method of  claim 1 , wherein the silver complex is at a molar concentration of about 0.01M to about 0.5M. 
     
     
         8 . The method of  claim 7 , wherein the silver complex is at a molar concentration of about 0.01M to about 0.1M. 
     
     
         9 . The method of  claim 1 , wherein the metal complex is at a molar concentration of about 0.1M to about 0.5M. 
     
     
         10 . The method of  claim 1 , wherein the molar ratio of metal complex to silver complex is from about 10:1 to about 1:1. 
     
     
         11 . The method of  claim 4 , wherein a silver deposit on the electrical contact is about 55% to about 99% weight percent and a nickel deposit is the balance. 
     
     
         12 . The method of  claim 5 , wherein a silver deposit on the electrical contact is about 90% to about 99% weight percent and a nickel deposit is the balance. 
     
     
         13 . The method of  claim 1 , wherein the silver-alloy plating bath further includes brighteners. 
     
     
         14 . A silver-alloy plated electrical contact formed in a silver-alloy plating bath having a silver complex, a metal complex including at least one of nickel or cobalt, wherein the metal complex forms about 0.3% to about 50% by weight of a content of a silver-alloy plated deposit. 
     
     
         15 . The silver-alloy plated electrical contact of  claim 14 , wherein the metal complex forms about 0.3% to about 10% percent by weight of the content of the silver-alloy plated deposit. 
     
     
         16 . The silver-alloy plated electrical contact of  claim 14 , wherein the metal complex is nickel citrate-ammonia or cobalt citrate-ammonia. 
     
     
         17 . The silver-alloy plated electrical contact of  claim 14 , wherein the silver complex is silver thiosulfate. 
     
     
         18 . The silver-alloy plated electrical contact of  claim 14 , wherein the silver complex is silver succinimide. 
     
     
         19 . The silver-alloy plated electrical contact of  claim 14 , wherein the silver-alloy plating bath has a pH of greater than 7.