External electrode connector

Abstract

An external electrode connector connects together external electrodes. The external electrode comprises a first metal layer, a first buffer layer and a second metal layer. The first buffer layer is formed on the first metal layer and electrically connected to the first metal layer. Conductors and elastic bodies are alternately provided or the conductors are arranged within a principal plane of the elastic body in the first buffer layer. The second metal layer is formed on the first buffer layer and electrically connected to the first buffer layer. The elastic body is lower in Young's modulus than the first metal layer, the conductor, and the second metal layer.

What is claimed is:  
     
         1 . An external electrode connector for connecting together external electrodes, comprising: 
 a first metal layer;    a first buffer layer which is formed on the first metal layer and electrically connected to the first metal layer and in which conductors and elastic bodies are alternately provided or in which the conductors are arranged within a principal plane of the elastic body; and    a second metal layer which is formed on the first buffer layer and electrically connected to the first buffer layer, wherein 
 the elastic body is lower in Young's modulus than the first metal layer, the conductor, and the second metal layer.  
   
     
     
         2 . The external electrode connector according to  claim 1 , further comprising: 
 a second buffer layer which is formed on the second metal layer and electrically connected to the second metal layer and in which conductors and elastic bodies are alternately provided or in which the conductors are arranged within a principal plane of the elastic body; and    a third metal layer which is formed on the second buffer layer and electrically connected to the second buffer layer, wherein 
 the conductors of the first buffer layer and the conductors of the second buffer layer are arranged at positions such that the conductors of the first buffer layer do not overlap the conductors of the second buffer layer with reference to the direction perpendicular to the principal plane of the second buffer layer.  
   
     
     
         3 . The external electrode connector according to  claim 1 , wherein the external electrodes correspond to an internal metal interconnection of a semiconductor element; the internal metal interconnection and the first metal layer are connected together; and the surface of the second metal layer constitutes a pad surface.  
     
     
         4 . The external electrode connector according to  claim 2 , wherein the external electrodes correspond to an internal metal interconnection of a semiconductor element; the internal metal interconnection and the first metal layer are connected together; and the surface of the second metal layer constitutes a pad surface.  
     
     
         5 . The external electrode connector according to  claim 3 , wherein barrier metal is provided between the internal metal interconnection and the first metal layer, between the first metal layer and the first buffer layer, or between the first buffer layer and the second metal layer.  
     
     
         6 . The external electrode connector according to  claim 4 , wherein barrier metal is provided between the internal metal interconnection and the first metal layer, between the first metal layer and the first buffer layer, or between the first buffer layer and the second metal layer.