Coating and electronic component

Abstract

The present invention provides a coating 10 provided on a conductor 20, the coating 10 has a first layer 12 containing palladium and a second layer 14 containing gold from the conductor 20 side, the first layer 12 has a first region 31 on the conductor 20 side and a second region 32 arranged nearer to the second layer 14 than the first region 31, and the second region 32 has a higher phosphorus concentration than the first region 31.

1 . A coating provided on a conductor, comprising:
 a first layer containing palladium and a second layer containing gold from the conductor side,   wherein the first layer has a first region, and a second region arranged nearer to the second layer than the first region, and   wherein the second region has a higher phosphorus concentration than the first region.   
     
     
         2 . The coating according to  claim 1 , wherein the first layer has an inside layer including the first region and an outside layer including the second region, from the conductor side. 
     
     
         3 . The coating according to  claim 1 , wherein at least one of the first region and the second region has the phosphorus concentration decreasing with decreasing distance to the conductor. 
     
     
         4 . The coating according to  claim 2 , wherein at least one of the first region and the second region has the phosphorus concentration decreasing with decreasing distance to the conductor. 
     
     
         5 . The coating according to  claim 1 , wherein the phosphorus concentration in the first region is not more than 0.01% by mass and the phosphorus concentration in the second region is more than 0.01% by mass and not more than 7% by mass. 
     
     
         6 . The coating according to  claim 2 , wherein the phosphorus concentration in the first region is not more than 0.01% by mass and the phosphorus concentration in the second region is more than 0.01% by mass and not more than 7% by mass. 
     
     
         7 . The coating according to  claim 3 , wherein the phosphorus concentration in the first region is not more than 0.01% by mass and the phosphorus concentration in the second region is more than 0.01% by mass and not more than 7% by mass. 
     
     
         8 . The coating according to  claim 1 , wherein the first layer has the thickness in the range of 0.1 to 0.4 μm. 
     
     
         9 . The coating according to  claim 2 , wherein the first layer has the thickness in the range of 0.1 to 0.4 μm. 
     
     
         10 . The coating according to  claim 3 , wherein the first layer has the thickness in the range of 0.1 to 0.4 μm. 
     
     
         11 . The coating according to  claim 1 , comprising an underlying layer containing nickel between the conductor and the first layer. 
     
     
         12 . The coating according to  claim 2 , comprising an underlying layer containing nickel between the conductor and the first layer. 
     
     
         13 . The coating according to  claim 3 , comprising an underlying layer containing nickel between the conductor and the first layer. 
     
     
         14 . An electronic component comprising a signal transmission part having the coating as defined in  claim 1 , and the conductor coated with the coating. 
     
     
         15 . An electronic component comprising a signal transmission part having the coating as defined in  claim 2 , and the conductor coated with the coating. 
     
     
         16 . An electronic component comprising a signal transmission part having the coating as defined in  claim 3 , and the conductor coated with the coating.