Membrane probing method using improved contact

• US 8,451,017 B2
• Filed: 06/18/2010
• Issued: 05/28/2013
• Est. Priority Date: 07/14/1998
• Status: Expired due to Fees

• Current Assignee: FormFactor Beaverton, Inc. (FormFactor Incorporated)
• Original Assignee: Cascade Microtech Incorporated (FormFactor Incorporated)
• Inventors: Gleason, K. Reed, Bayne, Michael A., Smith, Kenneth, Lesher, Timothy, Koxxy, Martin
• Primary Examiner(s): BENITEZ ROSARIO, JOSHUA
• Application Number:
  US12/818,521
• Publication Number:
  US 20100271060A1
• Time in Patent Office: 1,075 Days
• Field of Search: 324/754.03, 3247541-7542, 32475501-75511, 438 14- 18
• US Class Current: 324/754.2
• CPC Class Codes: G01R 1/06733 Geometry aspects G01R1/06727 takes precedence
• CPC Class Codes: G01R 1/06738 related to tip portion
• CPC Class Codes: G01R 1/0735 arranged on a flexible frame or film
• CPC Class Codes: G01R 3/00 Apparatus or processes specially adapted for the manufacture or maintenance of measuring instruments , e.g. of probe tips
• CPC Class Codes: H01R 13/2414 conductive elastomers
• CPC Class Codes: H01R 13/2464 characterized by the contact point
• CPC Class Codes: H01R 43/16 for manufacturing contact members, e.g. by punching and by bending
• CPC Class Codes: H05K 3/20 by affixing prefabricated conductor pattern H05K1/187, H05K3/046, H05K3/4658, H05K3/4682 takes precedence
• CPC Class Codes: H05K 3/4007 Surface contacts, e.g. bumps H05K3/4092 takes precedence; deposition of finish layers on pads H05K3/24; forming solder bumps H05K3/3457
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49004 including measuring or testing of device or component part
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49121 Beam lead frame or beam lead device
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49139 by inserting component lead or terminal into base aperture
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49165 by forming conductive walled aperture in base
• CPC Class Codes: Y10T 29/49169 Assembling electrical component directly to terminal or elongated conductor
• CPC Class Codes: Y10T 29/49174 Assembling terminal to elongated conductor
• CPC Class Codes: Y10T 29/49204 Contact or terminal manufacturing
• CPC Class Codes: Y10T 29/49208 : by assembling plural parts
• CPC Class Codes: Y10T 29/49218 : with deforming
• CPC Class Codes: Y10T 29/49815 : Disassembling
• CPC Class Codes: Y10T 29/49824 : to elastically deform work part or connector
• CPC Class Codes: Y10T 29/49826 : Assembling or joining
• CPC Class Codes: Y10T 29/53509 : Means to assemble tire stud into tire tread

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.

Claims

1. A probing assembly for probing an electrical device comprising:

(a) a plurality of contacts formed by locating conductive material within a plurality of depressions of a sacrificial substrate, each of said contacts having a length and a contacting portion spaced apart from an axis of moment of said contact, and each contact being electrically connected to a corresponding conductor; and

(b) an elastic assembly including a surface supporting said plurality of contacts, said elastic assembly operating in respect to each contact to urge each contact, when in pressing engagement with said electrical device, into tilting motion so that each contact is driven in accordance with said tilting motion into lateral scrubbing movement across said electrical device, each contact remaining supported by said elastic assembly along substantially all of said length during the tilting motion, wherein said plurality of contacts further includes a first conductive material that defines said contacting portion of said plurality of contacts and a second conductive material that supports said first conductive material, wherein said first conductive material is different from said second conductive material, and further wherein a thickness of said first conductive material in a direction that is perpendicular to said elastic assembly and at a point of contact between said electrical device and said contacting portion is greater than a thickness of said first conductive material in a direction that is perpendicular to a side of said first conductive material and in a location where said second conductive material supports said first conductive material.

2. The probing assembly of claim 1 including a base, said elastic assembly being tiltably coupled to said base so as to enable said elastic assembly to automatically tilt relative to said base toward a position parallel to said electrical device in response to pressing engagement between respective ones of said contacts and said electrical device.

3. The probing assembly of claim 1 wherein said contacts are provided in adjacent pairs and the respective lateral scrubbing movements of said contacts in each adjacent pair are in opposite directions.

4. The probing assembly of claim 1 wherein each contact is supported by a continuous portion of said elastic assembly.

5. The probing assembly of claim 1, wherein said contacting portion is configured to contact said electrical device, and further wherein said contacting portion includes at least one of a roughened surface pattern, a sharp ridge, a waffle pattern, and a pair of projections, wherein a spacing between said pair of projections is less than a diameter of a solder bump of said electrical device that said contacting portion is configured to contact.

6. The probing assembly of claim 1, wherein each of said plurality of contacts includes at least one substantially flat surface inclined relative to a perpendicular direction relative to said elastic assembly and defining an acute angle relative thereto.

7. The probing assembly of claim 1, wherein each of said plurality of contacts includes an elongate portion that defines the length, wherein said contacting portion is disposed in elevational relationship to said elongate portion, and further wherein said contacting portion and said elongate portion are integral with each other and formed free from interfacial layers.

8. The probing assembly of claim 1, wherein the probing assembly is configured to form a Kelvin connection with the electrical device, wherein said plurality of contacts is arranged in adjacent pairs, wherein each adjacent pair includes a first contact and a second contact, wherein the first contact is configured to provide an electric current to a contact pad of the electrical device, and further wherein the second contact is configured to detect a voltage of the contact pad.

9. A probing assembly for probing an electrical device comprising:

(a) a plurality of contacts formed by locating conductive material within a plurality of depressions of a sacrificial substrate, said plurality of contacts being substantially asymmetric, each of said contacts having a length and being electrically connected to a corresponding conductor; and

(b) an elastic assembly supporting said contacts, said elastic assembly operating in respect to each contact to urge each contact, when placed into pressing engagement with said electrical device, into tilting motion so that each contact is driven in accordance with said tilting motion into lateral scrubbing movement across said electrical device, and each contact remaining supported by said elastic assembly along substantially all of said length during the tilting motion, wherein said plurality of contacts further includes a plurality of contacting portions, wherein a first conductive material defines said contacting portion of said contacts and a second conductive material supports said first conductive material, wherein said first conductive material is different from said second conductive material, and further wherein a thickness of said first conductive material in a direction that is perpendicular to said elastic assembly and at a point of contact between said electrical device and said contacting portion is greater than a thickness of said first conductive material in a direction that is perpendicular to a side of said first conductive material and in a location where said second conductive material supports said first conductive material.

10. The probing assembly of claim 9 including a base, said elastic assembly being tiltably coupled to said base so as to enable said elastic assembly to automatically tilt relative to said base toward a position parallel to said electrical device in response to pressing engagement between respective ones of said contacts and said electrical device.

11. The probing assembly of claim 9 wherein each contact includes a contact bump fixedly joined in an off-centered location on said contact.

12. The probing assembly of claim 9 wherein said contacts are provided in adjacent pairs and the respective lateral scrubbing movements of said contacts in each adjacent pair are in opposite directions.

13. The probing assembly of claim 9 wherein each contact is supported by a continuous portion of said elastic assembly.

14. The probing assembly of claim 9, wherein each of said plurality of contacts includes a contacting portion, wherein said contacting portion is configured to contact said electrical device, and further wherein said contacting portion includes at least one of a roughened surface pattern, a sharp ridge, a waffle pattern, and a pair of projections, wherein a spacing between said pair of projections is less than a diameter of a solder bump of said electrical device that said contacting portion is configured to contact.

15. The probing assembly of claim 9, wherein each of said plurality of contacts includes at least one substantially flat surface inclined relative to a perpendicular direction relative to said elastic assembly and defining an acute angle relative thereto.

16. The probing assembly of claim 9, wherein each of said plurality of contacts includes an elongate portion that defines the length and a contacting portion in elevational relationship to said elongate portion, and further wherein said contacting portion and said elongate portion are integral with each other and formed free from interfacial layers.

17. The probing assembly of claim 9, wherein the probing assembly is configured to form a Kelvin connection with the electrical device, wherein said plurality of contacts is arranged in adjacent pairs, wherein each adjacent pair includes a first contact and a second contact, wherein the first contact is configured to provide an electric current to a contact pad of the electrical device, and further wherein the second contact is configured to detect a voltage of the contact pad.

18. A probing assembly for probing an electrical device comprising:

(a) a plurality of contacts formed by locating conductive material within a plurality of depressions of a sacrificial substrate, each of said contacts having a length and a contacting portion spaced apart from an axis of moment of said contact, and each contact being electrically connected to a corresponding conductor, wherein the probing assembly is configured to form a Kelvin connection with the electrical device, wherein said plurality of contacts is arranged in adjacent pairs, wherein each adjacent pair includes a first contact and a second contact, wherein the first contact is configured to provide an electric current to a contact pad of the electrical device, and further wherein the second contact is configured to detect a voltage of the contact pad; and

(b) an elastic assembly including a surface supporting said plurality of contacts, said elastic assembly operating in respect to each contact to urge each contact, when in pressing engagement with said electrical device, into tilting motion so that each contact is driven in accordance with said tilting motion into lateral scrubbing movement across said electrical device, each contact remaining supported by said elastic assembly along substantially all of said length during the tilting motion.

19. A probing assembly for probing an electrical device comprising:

(a) a plurality of contacts formed by locating conductive material within a plurality of depressions of a sacrificial substrate, said plurality of contacts being substantially asymmetric, each of said contacts having a length and being electrically connected to a corresponding conductor, wherein the probing assembly is configured to form a Kelvin connection with the electrical device, wherein said plurality of contacts is arranged in adjacent pairs, wherein each adjacent pair includes a first contact and a second contact, wherein the first contact is configured to provide an electric current to a contact pad of the electrical device, and further wherein the second contact is configured to detect a voltage of the contact pad; and

(b) an elastic assembly supporting said contacts, said elastic assembly operating in respect to each contact to urge each contact, when placed into pressing engagement with said electrical device, into tilting motion so that each contact is driven in accordance with said tilting motion into lateral scrubbing movement across said electrical device, and each contact remaining supported by said elastic assembly along substantially all of said length during the tilting motion.

20. A probing assembly for probing an electrical device comprising:

(a) a plurality of contacts formed by locating conductive material within a plurality of depressions of a sacrificial substrate, each of said contacts having a length and a contacting portion spaced apart from an axis of moment of said contact, and each contact being electrically connected to a corresponding conductor, wherein said contacting portion is configured to contact said electrical device, and further wherein said contacting portion includes at least one of a roughened surface pattern, a sharp ridge, a waffle pattern, and a pair of projections, wherein a spacing between said pair of projections is less than a diameter of a solder bump of said electrical device that said contacting portion is configured to contact; and

(b) an elastic assembly including a surface supporting said plurality of contacts, said elastic assembly operating in respect to each contact to urge each contact, when in pressing engagement with said electrical device, into tilting motion so that each contact is driven in accordance with said tilting motion into lateral scrubbing movement across said electrical device, each contact remaining supported by said elastic assembly along substantially all of said length during the tilting motion.

21. A probing assembly for probing an electrical device comprising:

(a) a plurality of contacts formed by locating conductive material within a plurality of depressions of a sacrificial substrate, said plurality of contacts being substantially asymmetric, each of said contacts having a length and being electrically connected to a corresponding conductor, wherein each of said plurality of contacts includes a contacting portion, wherein said contacting portion is configured to contact said electrical device, and further wherein said contacting portion includes at least one of a roughened surface pattern, a sharp ridge, a waffle pattern, and a pair of projections, wherein a spacing between said pair of projections is less than a diameter of a solder bump of said electrical device that said contacting portion is configured to contact; and

(b) an elastic assembly supporting said contacts, said elastic assembly operating in respect to each contact to urge each contact, when placed into pressing engagement with said electrical device, into tilting motion so that each contact is driven in accordance with said tilting motion into lateral scrubbing movement across said electrical device, and each contact remaining supported by said elastic assembly along substantially all of said length during the tilting motion.