Membrane probing method using improved contact

Abstract

A substrate, preferably constructed of a ductile material and a tool having the desired shape of the resulting device for contacting contact pads on a test device is brought into contact with the substrate. The tool is preferably constructed of a material that is harder than the substrate so that a depression can be readily made therein. A dielectric (insulative) layer, that is preferably patterned, is supported by the substrate. A conductive material is located within the depressions and then preferably lapped to remove excess from the top surface of the dielectric layer and to provide a flat overall surface. A trace is patterned on the dielectric layer and the conductive material. A polyimide layer is then preferably patterned over the entire surface. The substrate is then removed by any suitable process.

1 . (canceled) 
     
     
         2 . A probing assembly for probing an electrical device, the probing assembly comprising:
 an elastic assembly including a surface; and   a plurality of contacts, wherein the surface of the elastic assembly supports the plurality of contacts, wherein each contact of the plurality of contacts includes a contacting portion that is configured to electrically contact the electrical device, and further wherein at least one of:   (i) the contacting portion includes at least one of a roughened surface, a sharp ridge, a waffle pattern, and a pair of projections;   (ii) the plurality of contacts includes a first conductive material that defines the contacting portion and a second conductive material that supports the first conductive material, wherein the first conductive material is different from the second conductive material, and further wherein a thickness of the first conductive material at a point of contact between the electrical device and the contacting portion and in a direction that is perpendicular to the surface of the elastic assembly is greater than a thickness of the first conductive material in a direction that is perpendicular to a side of the first conductive material in a location where the second conductive material supports the first conductive material; and   (iii) wherein the probing assembly is configured to form a Kelvin connection with the electrical device, wherein the plurality of contacts is arranged in adjacent pairs, wherein each adjacent pair includes a first contact that is configured to provide an electric current to a contact pad of the electrical device and a second contact that is configured to detect a voltage of the contact pad.   
     
     
         3 . The probing assembly of  claim 2 , wherein the plurality of contacts is formed by locating a conductive material within a plurality of depressions of a sacrificial substrate. 
     
     
         4 . The probing assembly of  claim 2 , wherein the contacting portion of each contact is spaced apart from an axis of moment of each contact. 
     
     
         5 . The probing assembly of  claim 2 , wherein the plurality of contacts is electrically connected to a corresponding plurality of conductors. 
     
     
         6 . The probing assembly of  claim 5 , wherein the plurality of conductors is supported by the elastic assembly. 
     
     
         7 . The probing assembly of  claim 2 , wherein, when the plurality of contacts is in pressing engagement with the electrical device, the elastic assembly is configured to urge each contact into tilting motion so that each contact is driven in accordance with the tilting motion into lateral scrubbing movement across the electrical device. 
     
     
         8 . The probing assembly of  claim 7 , wherein each contact is supported by the surface of the elastic assembly across substantially all of a length thereof during the tilting motion. 
     
     
         9 . The probing assembly of  claim 7 , wherein the plurality of contacts is arranged in opposed pairs that include a first contact with a first contacting portion and a second contact with a second contacting portion, and further wherein respective lateral scrubbing movements of the first contact and the second contact are in opposite directions. 
     
     
         10 . The probing assembly of  claim 9 , wherein the first contact and the second contact simultaneously contact a single contact pad of the electrical device. 
     
     
         11 . The probing assembly of  claim 9 , wherein each contact has a respective length that is defined between a first end and a second end thereof, and further wherein the contacting portion is located nearer the first end than the second end. 
     
     
         12 . The probing assembly of  claim 11 , wherein the first contacting portion of the first contact is located nearer to the second contacting portion of the second contact than the second end of the first contact. 
     
     
         13 . The probing assembly of  claim 2 , wherein each contact is supported by a continuous portion of the elastic assembly. 
     
     
         14 . The probing assembly of  claim 2 , wherein the probing assembly further includes a base, and further wherein the elastic assembly is tiltably coupled to the base to permit the elastic assembly to automatically tilt relative to the base toward a position that is parallel to the electrical device responsive to pressing engagement between respective ones of the contacts and the electrical device. 
     
     
         15 . The probing assembly of  claim 2 , wherein each contact includes at least one substantially flat surface that is inclined to define an acute angle relative to the surface of the elastic assembly. 
     
     
         16 . The probing assembly of  claim 2 , wherein each contact includes an elongate portion, wherein the contacting portion is located in elevational relationship to the elongate portion, and further wherein the contacting portion and the elongate portion are integral with each other and formed free from interfacial layers. 
     
     
         17 . The probing assembly of  claim 2 , wherein the contacting portion includes at least one of a roughened surface, a sharp ridge, a waffle pattern, and a pair of projections. 
     
     
         18 . The probing assembly of  claim 2 , wherein the plurality of contacts includes a first conductive material that defines the contacting portion and a second conductive material that supports the first conductive material, wherein the first conductive material is different from the second conductive material, and further wherein a thickness of the first conductive material at a point of contact between the electrical device and the contacting portion and in a direction that is perpendicular to the surface of the elastic assembly is greater than a thickness of the first conductive material in a direction that is perpendicular to a side of the first conductive material in a location where the second conductive material supports the first conductive material. 
     
     
         19 . The probing assembly of  claim 2 , wherein the probing assembly is configured to form a Kelvin connection with the electrical device, wherein the plurality of contacts is arranged in adjacent pairs, wherein each adjacent pair includes a first contact that is configured to provide an electric current to a contact pad of the electrical device and a second contact that is configured to detect a voltage of the contact pad. 
     
     
         20 . The probing assembly of  claim 2 , wherein at least two of:
 (i) the contacting portion includes at least one of a roughened surface, a sharp ridge, a waffle pattern, and a pair of projections;   (ii) the plurality of contacts includes a first conductive material that defines the contacting portion and a second conductive material that supports the first conductive material, wherein the first conductive material is different from the second conductive material, and further wherein a thickness of the first conductive material at a point of contact between the electrical device and the contacting portion and in a direction that is perpendicular to the surface of the elastic assembly is greater than a thickness of the first conductive material in a direction that is perpendicular to a side of the first conductive material in a location where the second conductive material supports the first conductive material; and   (iii) wherein the probing assembly is configured to form a Kelvin connection with the electrical device, wherein the plurality of contacts is arranged in adjacent pairs, wherein each adjacent pair includes a first contact that is configured to provide an electric current to a contact pad of the electrical device and a second contact that is configured to detect a voltage of the contact pad.   
     
     
         21 . The probing assembly of  claim 2 , wherein
 (i) the contacting portion includes at least one of a roughened surface, a sharp ridge, a waffle pattern, and a pair of projections;   (ii) the plurality of contacts includes a first conductive material that defines the contacting portion and a second conductive material that supports the first conductive material, wherein the first conductive material is different from the second conductive material, and further wherein a thickness of the first conductive material at a point of contact between the electrical device and the contacting portion and in a direction that is perpendicular to the surface of the elastic assembly is greater than a thickness of the first conductive material in a direction that is perpendicular to a side of the first conductive material in a location where the second conductive material supports the first conductive material; and   (iii) wherein the probing assembly is configured to form a Kelvin connection with the electrical device, wherein the plurality of contacts is arranged in adjacent pairs, wherein each adjacent pair includes a first contact that is configured to provide an electric current to a contact pad of the electrical device and a second contact that is configured to detect a voltage of the contact pad.