Non-abrasive electrical test contact

Abstract

A hybrid non-abrasive electrical test contact is taught. Unlike cantilever contacts of the prior art, the invention is able to contact a lead of an integrated circuit device under test without abrading the plating on the lead. This is achieved by the contact possessing multiple loops to allow the tip of the contact to move not only downwards, but also sideways in a rocking motion. The tip of the contact is also shaped to contact the lead at only one point so as not to affect the solderability of the lead. In addition, tests have shown that the contact of the present invention has at least twice the working life span compared to another contact of the prior art.

1 . A contact for a test socket for a lead of a device, the contact of electrically-conductive material comprising: 
 a socket end;    a contact end; and    a resilient means comprising at least two loops,    wherein    the contact is adapted to provide a non-abrasive contact force with the lead.    
     
     
         2 . The contact of  claim 1  wherein the device is a semiconductor integrated device.  
     
     
         3 . The contact of  claim 1  wherein the electrically-conductive material is metal.  
     
     
         4 . The conductive material of  claim 3  wherein the metal is beryllium copper.  
     
     
         5 . The contact of  claim 1  wherein the socket end is adapted for connection to a test socket.  
     
     
         6 . The contact of  claim 1  wherein the contact end is profiled to permit contact with the lead at one point.  
     
     
         7 . The contact of  claim 1  wherein the contact end is adapted with a profile to permit a downward and lateral movement of the contact in conjunction with the resilient means.  
     
     
         8 . The contact of  claim 1  wherein the resilient means comprises two loops.  
     
     
         9 . The contact of  claim 1  wherein the resilient means comprises three loops.  
     
     
         10 . The contact of  claim 1  wherein the resilient means permits both a downward and a lateral movement of the contact as the device is inserted.  
     
     
         11 . The contact of  claim 1 , the contact made of one piece of the electrically-conductive material.  
     
     
         12 . The contact of  claim 1 , wherein the non-abrasive contact force is obtained by varying at least one parameter of the contact.  
     
     
         13 . The contact of  claim 12 , the at least one parameter comprising: 
 geometry of the loops;    number of loops;    choice of electrically-conductive material;    heat treatment for spring temper and hardness; and    geometry of the loops.    
     
     
         14 . The geometry of the loops of  claim 13;  the geometry of the loops comprising: 
 diameter of the loops;  
 distance of one loop to the next loop; and  
 magnitude of the change in direction of the loops.  
 
     
     
         15 . A method of maintaining the plating on an electrical lead of an integrated circuit device during testing, the method comprising providing a non-abrasive contact for a test socket.  
     
     
         16 . The method of  claim 15 , the non-abrasive test socket further comprising: 
 a socket end adapted for connection to the test socket;    a profiled contact end with a profile adapted to contact the electrical lead at only one point;    a resilient means adapted to move downwards and laterally in conjunction with the contact end, as the device is inserted,    thereby providing non-abrasive contact for the electrical lead.    
     
     
         17 . The method of  claim 15 , the resilient means comprising at least two loops.  
     
     
         18 . The method of  claim 16 , the method further comprising modifying at least one parameter for the non-abrasive contact to suit the lead of the device.