Lithographic contact elements

• US 7,287,322 B2
• Filed: 09/02/2004
• Issued: 10/30/2007
• Est. Priority Date: 12/02/1998
• Status: Expired due to Fees

• Current Assignee: FormFactor Incorporated
• Original Assignee: FormFactor Incorporated
• Inventors: Mathieu, Gaetan L., Eldridge, Benjamin N., Grube, Gary W.
• Primary Examiner(s): Arbes; Carl J.
• Application Number:
  US10/933,063
• Publication Number:
  US 20050148214A1
• Time in Patent Office: 1,153 Days
• Field of Search: 298/42, 298/43, 298/74, 298/76, 298/84, 438/14
• US Class Current: 29/842
• CPC Class Codes: G01R 1/06711 Probe needles; Cantilever beams; "Bump" contacts; Replaceable probe pins
• CPC Class Codes: G01R 1/06716 Elastic
• CPC Class Codes: G01R 1/06727 Cantilever beams
• CPC Class Codes: G01R 1/06744 Microprobes, i.e. having dimensions as IC details
• CPC Class Codes: G01R 1/06761 related to layers
• 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: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/11003 for holding or transferring the bump preform
• CPC Class Codes: H01L 2224/11334 using preformed bumps
• CPC Class Codes: H01L 2224/1147 using a lift-off mask
• CPC Class Codes: H01L 2224/11902 Multiple masking steps
• CPC Class Codes: H01L 2224/13012 in top view
• CPC Class Codes: H01L 2224/13017 being non uniform along the bump connector
• CPC Class Codes: H01L 2224/13019 at the bonding interface of the bump connector, i.e. on the surface of the bump connector
• CPC Class Codes: H01L 2224/1308 being stacked
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2225/06513 Bump or bump-like direct electrical connections between devices, e.g. flip-chip connection, solder bumps
• CPC Class Codes: H01L 2225/06527 Special adaptation of electrical connections, e.g. rewiring, engineering changes, pressure contacts, layout
• CPC Class Codes: H01L 23/49811 : Additional leads joined to the metallisation on the insulating substrate, e.g. pins, bumps, wires, flat leads H01L23/49827 takes precedence
• CPC Class Codes: H01L 24/16 : of an individual bump connector
• CPC Class Codes: H01L 25/0657 : Stacked arrangements of devices
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01011 : Sodium [Na]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• CPC Class Codes: H01L 2924/01022 : Titanium [Ti]
• CPC Class Codes: H01L 2924/01027 : Cobalt [Co]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01039 : Yttrium [Y]
• CPC Class Codes: H01L 2924/01042 : Molybdenum [Mo]
• CPC Class Codes: H01L 2924/01045 : Rhodium [Rh]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01055 : Cesium [Cs]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/1433 : Application-specific integrated circuit [ASIC]
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H05K 3/326 : the printed circuit having integral resilient or deformable parts, e.g. tabs or parts of flexible circuits H05K3/365 takes precedence
• CPC Class Codes: H05K 3/4092 : Integral conductive tabs, i.e. conductive parts partly detached from the substrate
• CPC Class Codes: Y10S 438/977 : Thinning or removal of substrate
• CPC Class Codes: Y10T 29/49147 : Assembling terminal to base
• CPC Class Codes: Y10T 29/49149 : by metal fusion bonding
• CPC Class Codes: Y10T 29/49155 : Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49204 : Contact or terminal manufacturing
• CPC Class Codes: Y10T 29/49208 : by assembling plural parts
• CPC Class Codes: Y10T 29/49222 : forming array of contacts or terminals
• CPC Class Codes: Y10T 29/49224 : with coating

Abstract

A method of forming an interconnection, including a spring contact element, by lithographic techniques. In one embodiment, the method includes applying a masking material over a first portion of a substrate, the masking material having an opening which will define a first portion of a spring structure, depositing a structure material (e.g., conductive material) in the opening, and overfilling the opening with the structure material, removing a portion of the structure material, and removing a first portion of the masking material. In this embodiment, at least a portion of the first portion of the spring structure is freed of masking material. In one aspect of the invention, the method includes planarizing the masking material layer and structure material to remove a portion of the structure material. In another aspect, the spring structure formed includes one of a post portion, a beam portion, and a tip structure portion.

Claims

1. A method for testing an electronic device, said method comprising:

providing a first substrate comprising a plurality of contact structures, each said contact structure comprising a post disposed on a terminal of said first substrate, a cantilevered beam attached to said post, and a tip attached to said beam, wherein said post, said beam, and said post are formed separately;

bringing ones of said contact structures into contact with terminals of said electronic device; and

testing said electronic device through said ones of said contact structures.

2. The method of claim 1, wherein said electronic device is a semiconductor device.

3. The method of claim 1, wherein said bringing step comprises pressing tips of said ones of said contact structures against said terminals of said electronic device and thereby forming temporary electrical connections with said terminals of said electronic device.

4. The method of claim 3, wherein, in response to said pressing of said tips of said ones of said contact structures against said terminals of said electronic device, beams of said ones of said contact structures deflect.

5. The method of claim 4, wherein said deflection of said beams of said ones of said contact structures allows said terminals of said electronic device to travel past first contact with said tips of said ones of said contact structures.

6. The method of claim 5, wherein said posts and said beams of said ones of said contact structures limit an amount of said travel of said terminals of said electronic device past first contact with said tips of said ones of said contact structures.

7. The method of claim 1, wherein:

said terminals of said electronic device are disposed in a first pattern, and

said tips of said ones of said contact structures are also disposed in said first pattern.

8. The method of claim 7, wherein:

posts of said ones of said contact structures are disposed in a second pattern, and

said second pattern is different than said first pattern.

9. The method of claim 8, wherein, in said first pattern, said tips of said ones of said contact structures are disposed closer together than said posts of said ones of said contact structures in said second pattern.

10. The method of claim 7, wherein, in said first pattern, said terminals of said electronic device are disposed in a linear pattern.

11. The method of claim 7, wherein, in said first pattern, said terminals of said electronic device are disposed in a rectangular pattern.

12. The method of claim 1, wherein at least one of said beams overlaps at least one other of said beams.

13. The method of claim 1, wherein said providing step comprises, for each said contact structure:

forming said post in a first opening in a first masking layer,

forming said beam in a second opening in a second masking layer, and

forming said tip in a third opening in a third masking layer.

14. The method of claim 13, wherein said providing step further comprises depositing at least one of said first masking layer, said second masking layer, and said third masking layer on a sacrificial substrate.

15. The method of claim 13, wherein said providing step further comprises:

depositing said first masking layer on said first substrate,

depositing said second masking layer on said first masking layer,

depositing said third masking layer on a sacrificial substrate, and

transferring said tip from said sacrificial substrate to said beam.

16. The method of claim 1, wherein said providing step comprises, for each said contact structure, forming at least one of said post, said beam, or said tip by depositing contact structure material in an opening in a masking layer and overfilling said opening, and removing a portion of said deposited contact structure material.

17. The method of claim 1, wherein said providing step comprises, for each said contact structure, forming said post, said beam, and said tip in a plurality of patterned masking materials.

18. The method of claim 1, wherein:

each said terminal on which a post of one of said contact structures is disposed is disposed on a first surface of said first substrate, said terminals being disposed in a first pattern on said first surface,

a plurality of second terminals are disposed in a second pattern on a second surface of said first substrate, and

said second pattern is different than said first pattern.

19. The method of claim 18, wherein, in said first pattern said terminals on said first surface of said first substrate are disposed in a tighter pitch than said second terminals are disposed in said second pattern.

20. An apparatus for making temporary electrical connections with terminals of an electronic device, said apparatus comprising:

a substrate comprising a plurality of first terminals disposed on a first surface of said substrate;

a plurality of posts, ones of said posts disposed on ones of said first terminals;

a plurality of cantilevered beams, ones of said beams attached to ones of said post, and

a plurality of tips, ones of said tips attached to ones of said beams,

wherein said posts, said beams, and said tips are separately formed, and

said terminals of said electronic device are disposed in a first pattern and ones of said tips are also disposed in said first pattern.

21. The apparatus of claim 20, wherein:

said ones of said posts are disposed in a second pattern, and

said second pattern is different than said first pattern.

22. The apparatus of claim 21, wherein, in said first pattern, said tips are disposed closer together than said posts in said second pattern.

23. The apparatus of claim 20, wherein each said beam is deflectable, allowing said terminals of said electronic device to travel past first contact with said tips.

24. The apparatus of claim 23, wherein said posts and said beams limit an amount of said travel of said terminals of said electronic device past first contact with said tips.

25. The apparatus of claim 20, wherein, in said first pattern, said terminals of said electronic device are disposed in a linear pattern.

26. The apparatus of claim 20, wherein, in said first pattern, said terminals of said electronic device are disposed in a rectangular pattern.

27. The apparatus of claim 20, wherein at least one of said beams overlaps at least one other of said beams.

28. The apparatus of claim 20, wherein said first terminals are disposed in a third pattern on said first surface of said substrate, and further comprising a plurality of second terminals disposed in a fourth pattern on a second surface of said substrate, wherein said fourth pattern is different than said third pattern.

29. The method of claim 28, wherein, in said third pattern said first terminals are disposed in a tighter pitch than said second terminals are disposed in said fourth pattern.