Special contact points for accessing internal circuitry of an integrated circuit

• US 6,456,099 B1
• Filed: 12/31/1998
• Issued: 09/24/2002
• Est. Priority Date: 12/31/1998
• Status: Expired due to Fees

• Current Assignee: FormFactor Incorporated
• Original Assignee: FormFactor Incorporated
• Inventors: Eldridge, Benjamin N., Khandros, Igor Y., Pedersen, David V., Whitten, Ralph G.
• Primary Examiner(s): Sherry, Michael
• Assistant Examiner(s): Nguyen, Jimmy
• Application Number:
  US09/224,169
• Time in Patent Office: 1,363 Days
• Field of Search: 324/754, 324/755, 324/765, 324/758, 324/158.1
• US Class Current: 324/755.05
• CPC Class Codes: G01R 1/07307 with individual probe elements, e.g. needles, cantilever beams or bump contacts, fixed in relation to each other, e.g. bed of nails fixture or probe card
• CPC Class Codes: G01R 31/2884 using dedicated test connectors, test elements or test circuits on the IC under test G01R31/2855 takes precedence
• CPC Class Codes: G01R 31/31723 Hardware for routing the test signal within the device under test to the circuits to be tested, e.g. multiplexer for multiple core testing, accessing internal nodes routing the test signal to or from the device under test G01R31/31926
• CPC Class Codes: H01L 22/32 Additional lead-in metallisation on a device or substrate, e.g. additional pads or pad portions, lines in the scribe line, sacrificed conductors arrangements for conducting electric current to or from the solid state body in operation H01L23/48
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/05554 being square
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/29099 Material
• CPC Class Codes: H01L 23/50 for integrated circuit devices, e.g. power bus, number of leadsH01L23/482 - H01L23/498 take precedence
• CPC Class Codes: H01L 23/60 Protection against electrostatic charges or discharges, e.g. Faraday shields
• 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 2924/00013 Fully indexed content
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/10253 Silicon [Si]

Abstract

One embodiment of the present invention concerns an integrated circuit that includes bond pads and special contact pads or points. The bond pads are for interfacing the integrated circuit as a whole with an external circuit, and are to be bonded to a package or circuit board. The bond pads are disposed on the die in a predetermined alignment such as a peripheral, grid, or lead-on-center alignment. The special contact pads are used to provide external test patterns to internal circuits and/or to externally monitor results from testing the internal circuits. The special contact pads may be advantageously located on the integrated circuit with a high degree of positional freedom. For one embodiment, the special contact pads may be disposed on the die at a location that is not in the same alignment as the bond pads. The special contact pads may be smaller than the bond pads so as not to increase the die size due to the special contact pads. The special contact points may also be used to externally program internal circuits (e.g., nonvolatile circuits) at the die or package level. The special contact points may also be used to select redundant circuits for faulty circuits.

Claims

1. A probe card comprising:

a substrate having a surface;

a plurality of first probe elements disposed on said substrate and configured to contact a plurality of first type of contact pads disposed at a plurality of first predetermined locations on an integrated circuit, each of said first probe elements comprising a contact portion that is disposed away from said surface of said substrate a first distance perpendicular to said surface; and

a plurality of second probe elements disposed on said substrate and configured to contact a plurality of second type of contact pads disposed at a plurality of second predetermine locations on the integrated circuit, each of said second probe elements comprising a contact portion that is disposed away from said surface of said substrate a second distance perpendicular to said surface of said substrate,

wherein each of said first type of contact pads extends to a greater height from a surface of said integrated circuit than each of said second type of contact pads, and said second distance is correspondingly greater than said first distance.

2. The probe card of claim 1, wherein the first and second probe elements comprise cantilevered probes.

3. The probe card of claim 1, wherein the first and second probe elements comprise contact balls.

4. The probe card of claim 1, wherein the first probe elements are arranged in a first predetermined alignment, and the second probe elements are arranged in a second predetermined alignment.

5. The probe card of claim 4, wherein the first predetermined alignment is a grid pattern.

6. The probe card of claim 4, wherein the first predetermined alignment is a rectangular pattern.

7. The probe card of claim 4, wherein the first and second probe elements are spring contact elements.

8. The probe card of claim 7, wherein the spring contact elements include pyramid-shaped tip contact structures.

9. The probe card of claim 4, wherein the first and second probe elements are COBRA-style probes.

10. The probe card of claim 1, wherein said contact portion of each of said first probe elements and said contact portion of each of said second probe elements each comprises a blade contact tip.

11. A probe card comprising:

a substrate having a surface;

a plurality of first probe means for contacting a first type of contact pad of an integrated circuit, said plurality of first probe means disposed in a first predetermined pattern on said substrate, each of said first probe means comprising a contact portion that is disposed away from said surface of said substrate a first distance perpendicular to said surface; and

a plurality of second probe means for contacting a second type of contact pad of said integrated circuit, said plurality of second probe means disposed in a second predetermined pattern on said substrate, each of said second probe means comprising a contact portion that is disposed away from said surface of said substrate a second distance perpendicular to said surface of said substrate,

wherein each said first type of contact pad extends to a greater height from a surface of said integrated circuit than each said second type of contact pad, and said second distance is correspondingly greater than said first distance.

12. The probe card of claim 11, wherein said first probe means and said second probe means comprise cantilevered probes.

13. The probe card of claim 11, wherein said first probe means and said second probe means comprise contact balls.

14. The probe card of claim 11, wherein said first probe means are arranged in a first alignment, and said second probe means are arranged in a second alignment, wherein said first alignment differs from said second alignment.

15. The probe card of claim 14, wherein said first alignment is a grid pattern.

16. The probe card of claim 14, wherein said first alignment is a rectangular pattern.

17. The probe card of claim 11, wherein said first probe means and said second probe means are spring contact elements.

18. The probe card of claim 17, wherein said spring contact elements include pyramid-shaped tip contact structures.

19. The probe card of claim 11, wherein said first probe means and said second probe means comprise COBRA-style probes.

20. The probe card of claim 11 wherein said first probe means and said second probe means comprise needle probes.

21. The probe card of claim 11 wherein said first probe means and said second probe means comprise resilient structures.

22. The probe card of claim 11 wherein said first type of contact pad is larger than said second type of contact pad.

23. The probe card of claim 11 wherein said first type of contact pad is larger in contact area than said second type of contact pad.

24. The probe card of claim 11 wherein said first type of contact pad is suitable for bonding to an integrated circuit package, and said second type of contact pad is not suitable for bonding to an integrated circuit package.

25. The probe card of claim 11 wherein said first type of contact pad is bonded to an integrated circuit package, and said second type of contact pad is not bonded to said integrated circuit package.

26. The probe card of claim 11, wherein said contact portion of each of said first probe means and said contact portion of each of said second probe means each comprises a blade contact tip.