Lead-free solder composition

Abstract

A solder composition includes about 20% to about 25% by weight tin, about 0.03% to about 3% by weight nickel, about 66% to about 75% by weight indium, and about 0.5% to about 2% by weight silver. The solder composition can further include about 0.1% to about 8% by weight antimony, about 0.03% to about 4% by weight copper, about 0.2% to about 6% by weight zinc, and/or about 0.01% to about 0.3% by weight germanium. The solder composition can be used to solder an electrical connector to an electrical contact surface on a glass component.

We claim: 
     
         1 . A solder composition, comprising:
 about 20% to about 25% by weight tin;   about 0.03% to about 3% by weight nickel;   about 66% to about 75% by weight indium; and   about 0.5% to about 2% by weight silver.   
     
     
         2 . The solder composition in accordance with  claim 1 , further comprising about 0.1% to about 8% by weight antimony. 
     
     
         3 . The solder composition in accordance with  claim 1 , further comprising about 0.03% to about 3% by weight copper. 
     
     
         4 . The solder composition in accordance with  claim 1 , further comprising about 0.2% to about 6% by weight zinc. 
     
     
         5 . The solder composition in accordance with  claim 1 , further comprising about 0.01% to about 0.3% by weight germanium. 
     
     
         6 . A vehicle glass component, comprising:
 at least one ply of glass having an electrically conductive component on at least one surface; and   an electrical connector electrically connected to the electrically conductive component via a soldered joint, wherein a solder composition forming the soldered joint comprises:
 about 20% to about 25% by weight tin, 
 about 0.03% to about 3% by weight nickel, 
 about 66% to about 75% by weight indium, and 
 about 0.5% to about 2% by weight silver. 
   
     
     
         7 . The vehicle glass component in accordance with  claim 6 , wherein the solder composition further comprises about 0.1% to about 8% by weight antimony. 
     
     
         8 . The vehicle glass component in accordance with  claim 6 , wherein the solder composition further comprises about 0.03% to about 4% by weight copper. 
     
     
         9 . The vehicle glass component in accordance with  claim 6 , wherein the solder composition further comprises about 0.2% to about 6% by weight zinc. 
     
     
         10 . The vehicle glass component in accordance with  claim 6 , wherein the solder composition further comprises about 0.01% to about 0.3% by weight germanium. 
     
     
         11 . The vehicle glass component in accordance with  claim 6 , wherein the electrically conductive component contains silver. 
     
     
         12 . A method of mixing indium, nickel, silver, and tin together to form a solder alloy, said method comprising the steps of:
 mixing indium and tin together to form a first molten mixture in amounts effective to provide about 66% to about 75% by weight indium and about 20% to about 25% by weight tin in the solder alloy;   mixing nickel and silver together to form a second molten mixture in amounts effective to provide about 0.03% to about 3% by weight nickel and about 0.5% to about 2% by weight silver in the solder alloy;   adding the second molten mixture to the first molten mixture; and   mixing the first molten mixture with the second molten mixture to form the solder alloy.   
     
     
         13 . The method in accordance with  claim 12 , further comprising adding antimony to the first molten mixture in an amount effective to provide about 0.1% to about 8% by weight antimony in the solder alloy. 
     
     
         14 . The method in accordance with  claim 12 , further comprising adding copper to the second molten mixture in an amount effective to provide about 0.03% to about 4% by weight copper in the solder alloy. 
     
     
         15 . The method in accordance with  claim 12 , further comprising adding zinc to the first molten mixture in an amount effective to provide about 0.2% to about 6% by weight zinc in the solder alloy. 
     
     
         16 . The method in accordance with  claim 12 , further comprising adding germanium to the first molten mixture in an amount effective to provide about 0.01% to about 0.3% by weight germanium in the solder alloy.