Methods of forming a contact array in situ on a substrate

Abstract

A substrate assembly is disclosed including a substrate and a plurality of spring-biased electrical contacts formed thereon for establishing electrical contact with the lead elements of an IC device. The substrate assembly also comprises a layer of resilient conductive material formed on a surface of the substrate, the spring-biased electrical contacts being formed in the resilient conductive material layer in situ on the substrate. Each spring-biased electrical contact includes a surface or surfaces configured to bias against and electrically contact an IC device lead element. The present invention also encompasses methods of fabricating substrate assemblies according to the invention, including heat treating the substrate assembly after formation to achieve desired spring characteristics.

1 . A method of fabricating a substrate assembly, comprising: 
 providing a substrate having a first surface and an opposing second surface;    forming a layer of resilient conductive material on at least a portion of at least one of the first and second surfaces of the substrate, the resilient conductive material exhibiting at least one first physical characteristic;    forming at least one electrically isolated spring-biased electrical contact in the layer of resilient conductive material;    forming at least one electrically isolated conductive trace in the layer of resilient conductive material, the at least one electrically isolated conductive trace having an end terminating at the at least one electrically isolated spring-biased electrical contact; and    treating the layer of resilient conductive material to achieve at least one second physical characteristic of the resilient conductive material.    
   
   
       2 . The method of  claim 1 , wherein the at least one first physical characteristic is selected to optimize properties of the layer of resilient conductive material for the act of forming at least one electrically isolated spring-biased electrical contact therein.  
   
   
       3 . The method of  claim 1 , wherein the at least one second physical characteristic is selected to optimize spring characteristics of the at least one electrically isolated spring-biased electrical contact.  
   
   
       4 . The method of  claim 1 , wherein at least one of forming at least one electrically isolated spring-biased electrical contact in the layer of resilient conductive material and forming at least one electrically isolated conductive trace in the layer of resilient conductive material is effected by etching the layer of resilient conductive material.  
   
   
       5 . The method of  claim 1 , further including disposing a dielectric layer over the layer of resilient conductive material, the dielectric layer being formed with at least one aperture therethrough substantially aligned with the at least one electrically isolated spring-biased electrical contact.  
   
   
       6 . The method of  claim 5 , further comprising forming the dielectric layer to be of sufficient thickness to encompass at least a portion of each lead element of an integrated circuit device contacting the at least one electrically isolated spring-biased electrical contact.  
   
   
       7 . The method of  claim 6 , further including forming the at least one aperture to be of frustoconical configuration.  
   
   
       8 . The method of  claim 5 , further including preforming the dielectric layer with the at least one aperture prior to disposing the dielectric layer over the layer of resilient conductive material.  
   
   
       9 . The method of  claim 5 , further including forming the dielectric layer in place over the layer of resilient conductive material and subsequently forming the at least one aperture therethrough.