Interconnect structure that controls spacing between a probe card and a contact substrate

Abstract

One embodiment of the present invention is a structure useful for testing circuits that includes: (a) a substrate having contactors on a first side and pads on a second side; (b) a card having pads on a first side; and (c) interconnectors that electrically connect the pads on the second side of the substrate with the pads on the card; wherein at least one of the interconnectors includes at least a portion that does not melt at temperatures in a range from about 183° C. to about 230° C., and the distance between the substrate and the card is determined by a dimension of the at least a portion.

1 . A structure useful for testing circuits that comprises: 
 a substrate having contactors on a first side and pads on a second side;    a card having pads on a first side; and    interconnectors that electrically connect the pads on the second side of the substrate with the pads on the card, wherein    at least one of the interconnectors includes at least a portion that does not melt at temperatures in a range from about 183° C. to about 230° C., and the distance between the substrate and the card is determined by a dimension of the at least a portion.    
     
     
         2 . The structure of  claim 1 , wherein the interconnectors are metal balls.  
     
     
         3 . The structure of  claim 2 , wherein at least one of the interconnectors is one of: a solid Cu ball, a solid Indium alloy ball, and a solid high lead solder ball.  
     
     
         4 . The structure of  claim 1 , wherein at least one of the interconnectors is a ceramic ball, wherein the ceramic is embedded with a conducting material.  
     
     
         5 . The structure of  claim 4 , wherein the conducting material comprises one or more of: gold, copper, silver, nickel, and an indium alloy.  
     
     
         6 . The structure of  claim 1 , further comprising an interconnector alignment film, wherein the interconnectors are partially disposed in vias in the interconnector alignment film.  
     
     
         7 . The structure of  claim 6 , wherein the dimension of the at least a portion is larger than a thickness of the interconnector alignment film.  
     
     
         8 . The structure of  claim 1 , wherein the substrate comprises one of: a rigid substrate, a flex substrate, a semi-flex substrate, a silicon substrate, and a glass substrate.  
     
     
         9 . The structure of  claim 1 , wherein the card is a Probe Card, and wherein the structure further comprises a stiffening mechanism affixed to a second side of the card.  
     
     
         10 . The structure of  claim 9 , wherein the stiffening mechanism comprises a ring structure.  
     
     
         11 . The structure of  claim 10 , wherein the ring structure comprises one or more of: radial arms, struts, and ribs.  
     
     
         12 . The structure of  claim 1 , wherein: (a) the substrate is a flexible substrate; (b) the contactors are disposed in an area on the first side of the substrate; and (c) the pads on the substrate are disposed outside of a projection of the area to the second side of the substrate.