Semiconductor test structure having a laser defined current carrying structure

Abstract

A test structure that is readily and inexpensively configurable to interface with dies having different bond pad configurations is achieved by providing a blank test membrane having a conductive coating or a matrix of conductive lines formed thereon. Once a die bond pad configuration is known, the test membrane can be configured for the die bond pads by using a laser under software control to define connection pads correlating to the die bond pads and also to define interconnecting conductive traces from the connecting pads to contact pads that can be connected to test equipment. In one embodiment, the laser operates to ablate a continuous conductive coating, so as to form conductive pads and traces. In another embodiment, the laser is used to cut various lines in a matrix of conductive lines, so as to define conductive paths from the bond pads to the contact pads for connection to the test equipment.

What is claimed is:  
     
         1 . A method of forming a test structure for interfacing to test equipment a semiconductor die having bond pads at predefined coordinates using a machine controlled laser, the test equipment having contact points at predefined locations, comprising: 
 forming a conductive material layer on a substrate;    defining first coordinates on the substrate corresponding to at least one predefined bond pad coordinate;    defining second coordinates on the substrate corresponding to at least one predefined test equipment contact point location;    defining third coordinates on the substrate corresponding to an interconnect between the predefined bond pad and the predefined test equipment contact point location;    ablating portions of the conductive material layer using a laser beam, while leaving unablated portions of the conductive material at the first, second and third coordinates.    
     
     
         2 . The method of  claim 1  further comprising plating a second conductive material onto the unablated portions of the conductive material.  
     
     
         3 . The method of  claim 1  wherein the conductive material layer comprises a continuous layer prior to the step of ablating.  
     
     
         4 . The method of  claim 1  wherein the conductive material layer comprises a matrix of conductive lines.  
     
     
         5 . The method of  claim 1  wherein said substrate is comprised of silicon.  
     
     
         6 . The method of  claim 2  wherein said conductive material layer and said second conductive material are selected from the group consisting of tin, gold, aluminum, and copper.  
     
     
         7 . The method of  claim 1  wherein the substrate is formed of a polyamide material.  
     
     
         8 . A test structure for testing a semiconductor die having a plurality of bond pads, the test structure comprising: 
 a substrate;    at least one predefined bond pad located on a top surface of the substrate to connect to the semiconductor die;    at least one predefined contact point on the substrate to connect to test equipment; and    at least one interconnect located on the top surface of the substrate, wherein the at least one interconnect is formed by ablating portions of a conductive material on the top surface of the substrate using a laser to form a conductive trace between the at least one predefined bond pad and the at least one predefined contact point.    
     
     
         9 . The test structure of  claim 8  wherein the ablating results in leaving unablated portions of the conductive material at the at least one predefined bond pad, predefined contact point, and interconnect.  
     
     
         10 . The test structure of  claim 8  wherein the substrate is comprised of silicon.  
     
     
         11 . The test structure of  claim 8  wherein the substrate is comprised of a polyamide material.  
     
     
         12 . The test structure of  claim 8  wherein the conductive material is selected from the group consisting of tin, gold, aluminum, and copper.  
     
     
         13 . A system for testing a semiconductor die comprising: 
 a test structure having a substrate with at least one contact point, at least one connection pad, and at least one interconnection located on a top surface of the substrate; and    a carrier in which the test structure is seated, the carrier having a contact point for connecting test equipment to the test structure;    wherein the at least one interconnection is formed by using the beam laser to form a conductive trace between the at least one contact point and the at least one connection pad.    
     
     
         14 . The system of  claim 13  wherein the substrate is comprised of a polyamide material.  
     
     
         15 . The system of  claim 13  wherein the substrate is comprised of a polyamide material.  
     
     
         16 . The system of  claim 13  wherein the conductive trace is formed from ablating conductive material on the top surface of the substrate.  
     
     
         17 . The system of  claim 16  wherein the conductive material is selected from the group consisting of tin, gold, aluminum, and copper.  
     
     
         18 . The system of  claim 16  wherein the conductive material layer comprises a continuous layer prior to the ablating of the conductive material.  
     
     
         19 . The system of  claim 16  wherein the conductive material layer comprises a matrix of conductive lines.  
     
     
         20 . The test structure of  claim 16  wherein the ablating results in leaving unablated portions of the conductive material at the at least one predefined bond pad, predefined contact point, and interconnect.