Probe head having a membrane suspended probe

• US 7,514,944 B2
• Filed: 03/10/2008
• Issued: 04/07/2009
• Est. Priority Date: 07/07/2004
• Status: Expired due to Fees

• Current Assignee: FormFactor Beaverton, Inc. (FormFactor Incorporated)
• Original Assignee: Cascade Microtech Incorporated (FormFactor Incorporated)
• Inventors: Jolley, Michael, Van Syckel, Victoria, Smith, Kenneth
• Primary Examiner(s): Hollington; Jermele M
• Application Number:
  US12/075,341
• Publication Number:
  US 20080157795A1
• Time in Patent Office: 393 Days
• Field of Search: None
• US Class Current: 324/755.09
• CPC Class Codes: G01R 1/0735 arranged on a flexible frame or film
• CPC Class Codes: G01R 1/07371 using an intermediate card or back card with apertures through which the probes pass

Abstract

A probe head including an elastic membrane capable of exerting a restoring force when one of the surfaces of the elastic membrane is distorted. A conductive probe includes a beam having a first end and a second end, with a probe tip proximate the first end for contacting a device under test. A beam contact proximate the second end of the beam. The beam being movable to deform at least one surface of the elastic membrane.

Claims

1. A probe head comprising:

(a) an elastic membrane having a first surface and an opposing second surface, said elastic membrane capable of exerting a restoring force when one of said first and said second surfaces is distorted; and

(b) an elongate conductive probe having a first end and a second end, a probe tip proximate said first end of said probe for contacting a device under test nearer said second surface than said first surface, and a contact proximate said second end of said probe and exposed from said first surface of said elastic membrane, said beam movable to deform said second surface of said elastic membrane.

2. The probe head of claim 1 further comprising an insulating member interposed between said probe and said elastic membrane, said insulating member movable by said probe to deform said second surface of said elastic membrane.

3. The probe head of claim 1 wherein said probe contact projects from said probe at least flush with said first surface of said elastic membrane.

4. A probe head comprising:

(a) an elastic membrane having a first surface and an opposing second surface, said elastic membrane capable of exerting a restoring force when at least one of said first and said second surfaces is distorted;

(b) an elongate conductive probe having a first end, a second end, and a depth;

a probe tip proximate said first end of said probe and projecting from said probe in a first direction; and

a contact projecting in a second direction from said probe proximate said second end of said probe and exposed to contact from said first surface of said elastic membrane; and

(c) a first insulating member having a first surface engaging said probe and a second surface engaging said second surface of said elastic member, said first insulating member movable by said probe to deform said second surface of said elastic membrane.

5. The probe head of claim 4 wherein said contact projects at least flush with said first surface of said elastic membrane.

6. The probe head of claim 4 further comprising a second insulating member having a first surface proximate said first surface of said first insulating member and a thickness approximating said depth of said probe.

7. A probing assembly comprising:

(a) a space transformer including an exposed conductive space transformer contact;

(b) an elastic membrane having a first surface restrainable by said space transformer and an opposing second surface, said elastic membrane capable of exerting a restoring force when said second surface is distorted; and

(c) a conductive probe having a first end and a second end, a probe tip proximate said first end of probe for contacting a device under test nearer said second surface of said membrane than said first surface of said membrane, and a contact proximate said second end of said probe and arranged to contact said space transformer contact, said probe movable to deform said second surface of said elastic membrane.

8. The probing assembly of claim 7 further comprising a first insulating member interposed between said probe and said elastic membrane, said first insulating member movable by said probe to deform said second surface of said elastic membrane.

9. The probe head of claim 7 wherein said probe contact projects from said probe at least flush with said first surface of said elastic membrane.

10. A probing assembly comprising:

(a) a space transformer having a surface and including a conductive space transformer contact exposed at said surface;

(b) an elastic membrane having a first surface restrainable by said surface of said space transformer and an opposing second surface, said elastic membrane capable of exerting a restoring force when said second surface is distorted;

(c) a conductive probe having a first end, a second end, and a depth, a probe tip proximate said first end of said probe and projecting from said probe in a first direction, and a contact proximate said second end of said probe and arranged to contact said space transformer contact; and

(d) a first insulating member having a first surface engaging said probe and a second surface engaging said second surface of said elastic member, said insulating member movable by said probe to deform said second surface of said elastic membrane.

11. The probe head of claim 10 wherein said probe contact projects from said probe in a direction opposite said first direction and at least flush with said first surface of said elastic membrane.

12. The probe head of claim 10 further comprising a second insulating member having a first surface proximate said first surface of said first insulating member and a thickness approximating said depth of said probe.

13. A method of reducing an inductance of a needle card probe assembly including a needle card probe head and a space transformer having a space transformer contact arranged to interface with said needle card probe head, said method comprising the steps of:

(a) disengaging said needle card probe head from said space transformer; and

(b) engaging said space transformer with a membrane probe head comprising;

(i)an elastic membrane having a first surface restrainable by said space transformer and an opposing second surface, said elastic membrane capable of exerting a restoring force when second surface is distorted;

(ii) a conductive probe having a first end, a second end, and a depth, a probe tip proximate said first end of said probe and projecting from said probe in a first direction, and a probe contact proximate said second end of said probe and arranged to contact said space transformer contact; and

(iii) a first insulating member having a first surface engaging said probe and a second surface engaging said second surface of said elastic member, said insulating member movable by said probe to deform said second surface of said elastic membrane.

14. The method of claim 13 wherein said probe contact of said membrane probe head projects from said probe in a direction opposite said first direction and at least flush with said first surface of said elastic membrane.

15. The method of claim 13 wherein said membrane probe head further comprising a second insulating member having a first surface proximate said first surface of said first insulating member and a thickness approximating said depth of said probe.

16. The method of claim 13 wherein said conductive probe has a single path inductance less than one nano-Henry.

17. The method of claim 13 wherein said conductive probe has a single path inductance less than one-half nano-Henry.

18. The method of claim 13 wherein said conductive probe has a single path inductance less than one-fourth nano-Henry.

19. The method of claim 13 wherein the step of engaging said space transformer with said membrane probe head comprises the step adhering a tile including said elastic membrane and said conductive probe to a surface of said space transformer.

20. A probe head comprising:

(a) an elastic membrane having a first surface and an opposing second surface, said elastic membrane capable of exerting a restoring force when one of said first and said second surfaces is distorted; and

(b) a conductive probe having a first end and a second end, a probe tip proximate said first end of said probe for contacting a device under test located closer to said second surface than said first surface, and a contact proximate said second end of said beam and comprising a contact end that is located closer to said first surface than said second surface of said elastic membrane, said beam movable to deform at least one of said first surface and said second surface of said elastic membrane.

21. The probe head of claim 20 further comprising an insulating member interposed between said probe and said elastic membrane, said insulating member movable by said probe to deform said second surface of said elastic membrane.

22. The probe head of claim 20 wherein said probecontact end is located substantially flush with said first surface of said elastic membrane.

23. A probe head comprising:

(a) an elastic membrane having a first surface and an opposing second surface, said elastic membrane capable of exerting a restoring force when at least one of said first and said second surfaces is distorted;

(b) a conductive probe having a first end, a second end, and a depth;

a probe tip proximate said first end of said probe and projecting from said probe in a first direction; and

a contact projecting in a second direction from said probe proximate said second end of said probe and having a contact end distal of said probe and located nearer said first surface of said elastic membrane than said second surface of said elastic membrane; and

(c) a first insulating member having a first surface engaging said probe and a second surface engaging said second surface of said elastic member, said first insulating member movable by said probe to deform at least one of first surface and said second surface of said elastic membrane.

24. The probe head of claim 23 wherein said beam contact end is located substantially flush with said first surface of said elastic membrane.

25. The probe head of claim 23 further comprising a second insulating member having a first surface proximate said first surface of said first insulating member.

26. A probing assembly comprising:

(a) a space transformer including an exposed conductive space transformer contact;

(b) an elastic membrane having a first surface restrainable by said space transformer and an opposing second surface, said elastic membrane capable of exerting a restoring force when said second surface is distorted; and

(c) a conductive probe comprising;

(

i) said probe having a first end and a second end;

(ii) a probe tip proximate said first end of said beam for contacting a device under test located nearer said second surface of said membrane than said first surface of said membrane; and

(iii) a contact proximate said second end of said probe and arranged to contact said space transformer contact at a location nearer said first surface of said membrane than said second surface of said membrane, said probe movable to deform at least one of said first surface said second surface of said membrane.

27. The probing assembly of claim 26 further comprising a first insulating member interposed between said probe and said elastic membrane, said first insulating member movable by said probe to deform said second surface of said elastic membrane.

28. The probe head of claim 26 wherein said probe contact projects from said beam to a location at least flush with said first surface of said elastic membrane.

29. A probing assembly comprising:

(a) a space transformer having a surface and including a conductive space transformer contact exposed at said surface;

(b) an elastic membrane having a first surface restrainable by said surface of said space transformer and an opposing second surface, said elastic membrane capable of exerting a restoring force when said second surface is distorted;

(c) a conductive probe comprising;

(i) said probe having a first end, a second end, and a depth;

(ii) a probe tip proximate said first end of said probe and projecting from said probe in a first direction; and

(iii) a probe contact proximate said second end of said probe and arranged to contact said space transformer contact at a location nearer said first surface of said elastic membrane than said second surface of said elastic membrane; and

(d) a first insulating member having a first surface engaging said probe and a second surface engaging said second surface of said elastic member, said insulating member movable by said probe to deform said second surface of said elastic membrane.

30. The probe head of claim 29 wherein said contact projects from said probe in a direction opposite said first direction and terminates at a location that is at least flush with said first surface of said elastic membrane.

31. The probe head of claim 29 further comprising a second insulating member having a first surface proximate said first surface of said first insulating member and a thickness approximating said depth of said probe.

32. A method of reducing an inductance of a needle card probe assembly including a needle card probe head and a space transformer having a space transformer contact arranged to interface with said needle card probe head, said method comprising the steps of:

(a)disengaging said needle card probe head from said space transformer; and

(b)engaging said space transformer with a membrane probe head comprising;

(i) an elastic membrane having a first surface restrainable by said space transformer and an opposing second surface, said elastic membrane capable of exerting a restoring force when second surface is distorted;

(ii) a conductive probe having a first end, a second end, and a depth, a probe tip proximate said first end of said probe and projecting from said probe in a first direction, and a contact proximate said second end of said probe and arranged to contact said space transformer contact at a location nearer said first surface of said membrane than said second surface of said membrane; and

(iii) a first insulating member having a first surface engaging said probe and a second surface engaging said second surface of said elastic member, said insulating member movable by said probe to deform said second surface of said elastic membrane.

33. The method of claim 32 wherein said contact of said membrane probe head projects from said beam in a direction opposite said first direction and terminates at a location at least flush with said first surface of said elastic membrane.

34. The method of claim 32 wherein said membrane probe head further comprising a second insulating member having a first surface proximate said first surface of said first insulating member and a thickness approximating said depth of said probe.

35. The method of claim 32 wherein said conductive probe has a single path inductance less than one nano-Henry.

36. The method of claim 32 wherein said conductive probe has a single path inductance less than one-half nano-Henry.

37. The method of claim 32 wherein said conductive probe has a single path inductance less than one-fourth nano-Henry.

38. The method of claim 32 wherein the step of engaging said space transformer with said membrane probe head comprises the step adhering a tile including said elastic membrane and said conductive probe to a surface of said space transformer.