Novel zero insertion force sockets using negative thermal expansion materials

Abstract

A socket device for receiving a connection pin is disclosed, the socket device including a substrate having an upper surface. The socket device includes a connection pad disposed on the upper surface and a first layer disposed on the upper surface and on the connection pad. The first layer includes material having an overall positive coefficient of thermal expansion. The socket device includes a second layer disposed on the first layer. The second layer includes material having an overall negative coefficient of thermal expansion. The socket device also includes a contact hole formed in the first and second layers exposing a portion of the connection pad.

What is claimed is:  
     
         1 . A socket device for receiving a connection pin or solder ball, said socket device comprising: 
 a substrate having an upper surface;    a connection pad disposed on said upper surface;    a layer disposed on said upper surface and on said connection pad, said layer including material having an overall negative coefficient of thermal expansion;    a contact hole formed in said layer exposing a portion of said connection pad.    
     
     
         2 . A socket device for receiving a connection pin or solder ball, said socket device comprising: 
 a substrate having an upper surface;    a connection pad disposed on said upper surface;    a first layer disposed on said upper surface and on said connection pad, said first layer including material having an overall positive coefficient of thermal expansion;    a second layer disposed on said first layer, said second layer including material having an overall negative coefficient of thermal expansion; and    a contact hole formed in said first and second layers exposing a portion of said connection pad.    
     
     
         3 . The socket device of    claim 2   , including a bonding layer disposed between said first and second layers, said bonding layer bonding said first and second layers together.  
     
     
         4 . The socket device of    claim 2   , wherein said contact hole includes a first portion formed in said first layer having a first linear dimension and a second portion formed in said second layer having a second linear dimension smaller than said first linear dimension.  
     
     
         5 . The socket device of    claim 1   , wherein said layer includes zirconium tungstate.  
     
     
         6 . The socket device of    claim 2   , wherein said second layer includes zirconium tungstate.  
     
     
         7 . The socket device of    claim 5   , wherein said layer including zirconium tungstate has a substantially isotropic negative thermal expansion behavior.  
     
     
         8 . The socket device of    claim 6   , wherein said second layer including zirconium tungstate has a substantially isotropic negative thermal expansion behavior.  
     
     
         9 . The socket device of    claim 7    or    8   , wherein said substantially isotropic negative thermal expansion behavior is exhibited at least in a temperature range of from about 100° C. to about 200° C.  
     
     
         10 . The socket device of    claim 9   , wherein said substantially isotropic negative thermal expansion behavior is exhibited at least at a temperature of about 150°C.  
     
     
         11 . The socket device of    claim 1   , wherein said contact hole includes a chamfer formed in said layer.  
     
     
         12 . The socket device of    claim 2   , wherein said contact hole includes a chamfer formed in said second layer.  
     
     
         13 . The socket device of    claim 3   , wherein said contact hole includes a first portion formed in said first layer having a first linear dimension and a second portion formed in said second layer having a second linear dimension smaller than said first linear dimension.  
     
     
         14 . The socket device of    claim 3   , wherein said second layer includes zirconium tungstate.  
     
     
         15 . The socket device of    claim 14   , wherein said second layer including zirconium tungstate has a substantially isotropic negative thermal expansion behavior.  
     
     
         16 . The socket device of    claim 15   , wherein said substantially isotropic negative thermal expansion behavior is exhibited at least in a temperature range of from about 100° C. to about 200° C.  
     
     
         17 . The socket device of    claim 16   , wherein said substantially isotropic negative thermal expansion behavior is exhibited at least at a temperature of about 150° C.