High strength and high elongation ratio of au alloy bonding wire

Abstract

To acquire the best combination of elongation and break strength on the Au alloy bonding wire. Adding 0.5-30 wt % of at least one element among Cu, Ag, Pd and Pt to high purity Au, a flat area about elongation ratio change appears between the range of 450-650° C. of heat-treatment temperature at wire drawing. Though the wire strength becomes decrease at this range of temperature, the strength is maintained at higher level against the heat treatment temperature of a standard elongation ratio of 4% of high purity Au alloy wire. Therefore, by the heat treatment of this flat range, Au alloy bonding wire, which has certain level of strength regardless of the temperature change, is acquired. Moreover, by selecting appropriate temperature range, different strength characteristics wires corresponding to the elongation ratio are acquired.

1 . Bonding wire for semiconductor device comprising: bonding wires consist of 0.5-30 mass % of at least one element among Cu, Ag, and Pd or Pt and residual Au, and bonding wires are heat-treated in the range of 450-650° C. where increased elongation ratio with increasing heat-treatment temperature becomes flat. 
     
     
         2 . Bonding wire for semiconductor device comprising: bonding wires consist of 0.5-30 mass % in total at least one element among Cu, Ag, and Pd or Pt and residual Au, and bonding wires are heat-treated in the range of 450-650° C. where increased elongation ratio with increasing heat-treatment temperature becomes flat. 
     
     
         3 . Bonding wire for semiconductor device described in  claim 1  comprising: bonding wires consist of 0.5-30 mass % of at least one element among Cu, Ag, and Pd or Pt and residual Au, and bonding wires are quenched after heat-treatment in the range of 450-650° C. where increased elongation ratio with increasing heat-treatment temperature becomes flat. 
     
     
         4 . Bonding wire for semiconductor device described in  claim 1  comprising: the above mentioned Au alloy consists of 0.5-5 mass % of Cu and residual Au. 
     
     
         5 . Bonding wire for semiconductor device described in  claim 1  comprising: the above mentioned Au alloy consists of 5-20 mass % of Ag and residual Au. 
     
     
         6 . Bonding wire for semiconductor device described in  claim 1  comprising: the above mentioned Au alloy consists of 0.5-2 mass % of Pd and residual Au. 
     
     
         7 . Bonding wire for semiconductor device described in  claim 1  comprising: the above mentioned heat-treatment is done within the range from starting temperature (hereinafter it is expressed as “ST”), where elongation ratio becomes flat to ST+200° C. 
     
     
         8 . Bonding wire for semiconductor device described in  claim 2  comprising: bonding wires consist of 0.5-30 mass % of at least more than one element among Cu, Ag, and Pd or Pt and residual Au, and bonding wires are quenched after heat-treatment in the range of 450-650° C. where increased elongation ratio with increasing heat-treatment temperature becomes flat. 
     
     
         9 . Bonding wire for semiconductor device described in  claim 2  comprising: the above mentioned Au alloy consists of 0.5-5 mass % of Cu and residual Au. 
     
     
         10 . Bonding wire for semiconductor device described in  claim 2  comprising: the above mentioned Au alloy consists of 5-20 mass % of Ag and residual Au. 
     
     
         11 . Bonding wire for semiconductor device described in  claim 2  comprising: the above mentioned Au alloy consists of 0.5-2 mass % of Pd and residual Au. 
     
     
         12 . Bonding wire for semiconductor device described in  claim 2  comprising: the above mentioned heat-treatment is done within the range from starting temperature (hereinafter it is expressed as “ST”), where elongation ratio becomes flat to ST+200° C.