Probe for testing a device under test

• US 7,898,273 B2
• Filed: 02/17/2009
• Issued: 03/01/2011
• Est. Priority Date: 05/23/2003
• Status: Expired due to Fees

• Current Assignee: Cascade Microtech Incorporated (FormFactor Incorporated)
• Original Assignee: Cascade Microtech Incorporated (FormFactor Incorporated)
• Inventors: Gleason, K. Reed, Andrews, Mike, Martin, John, Lesher, Tim
• Primary Examiner(s): Nguyen; Vinh P
• Application Number:
  US12/378,659
• Publication Number:
  US 20090267625A1
• Time in Patent Office: 742 Days
• Field of Search: None
• US Class Current: 324/754.03
• CPC Class Codes: G01R 1/06738 related to tip portion
• CPC Class Codes: G01R 1/06772 High frequency probes
• CPC Class Codes: G01R 1/07342 the body of the probe being at an angle other than perpendicular to test object, e.g. probe card

Abstract

A probe measurement system for measuring the electrical characteristics of integrated circuits or other microelectronic devices at high frequencies.

Claims

1. A probe comprising:

(a) a dielectric substrate having a pair of opposing major surfaces;

(b) an elongate conductor suitable to be electrically interconnected to a test signal supported by said substrate;

(c) a conductive member suitable to be electrically interconnected to a ground signal supported by said substrate wherein said conductive member together with said elongate conductor form a controlled impedance transmission structure;

(d) a conductive path between a first side of said substrate and a second side of said substrate in a manner free from an air gap between the conductive path and an edge of said substrate for at least a majority of the thickness of said substrate and said conductive path free from electrical interconnection with said conductive member; and

(e) a contact electrically interconnected to said conductive path for testing a device under test.

2. The probe of claim 1 wherein said controlled impedance transmission structure is microstrip.

3. The probe of claim 1 wherein said edge is a via through said substrate.

4. The probe of claim 1 wherein said edge is an exterior peripheral edge of said substrate.

5. The probe of claim 1 wherein said elongate conductor is electrically interconnected to a central conductor of a coaxial cable.

6. The probe of claim 5 wherein said conductive member is electrically connected to a conductor surrounding said central conductor of said coaxial cable.

7. The probe of claim 6 wherein said substrate is supported by said coaxial cable.

8. The probe of claim 7 wherein said substrate is supported by a shelf of said coaxial cable.

9. The probe of claim 1 wherein said conductive member is substantially planar.

10. The probe of claim 1 wherein said dielectric substrate is semi-flexible.

11. The probe of claim 10 wherein said dielectric substrate is a membrane.

12. The probe of claim 1 wherein said dielectric substrate has a dielectric constant less than 7.

13. The probe of claim 1 wherein said dielectric substrate has a dielectric constant less than 5.

14. The probe of claim 1 wherein said dielectric substrate has a dielectric constant less than 4.

15. The probe of claim 1 wherein said dielectric substrate has a dielectric constant less than 2.

16. The probe of claim 1 wherein said ground signal is zero volts.

17. The probe of claim 1 wherein said conductive member covers greater than 50% of said second side of said substrate.

18. The probe of claim 1 wherein said conductive member covers greater than 60% of said second side of said substrate.

19. The probe of claim 1 wherein said conductive member covers greater than 70% of said second side of said substrate.

20. The probe of claim 1 wherein said conductive member covers greater than 80% of said second side of said substrate.

21. The probe of claim 1 wherein said conductive member covers greater than 90% of said second side of said substrate.

22. The probe of claim 1 wherein said conductive member, said elongate conductor, and said substrate collectively form a microstrip transmission structure.

23. The probe of claim 1 wherein said conductive member laterally surrounds at least 50% of said contact.

24. The probe of claim 1 wherein said conductive member laterally surrounds at least 75% of said contact.

25. The probe of claim 1 wherein said conductive member laterally surrounds at least 100% of said contact.

26. The probe of claim 1 wherein said contact is in the form of a bump.

27. The probe of claim 1 wherein said substrate has a thickness less than 40 microns.

28. The probe of claim 1 wherein said substrate has a thickness less than 30 microns.

29. The probe of claim 1 wherein said substrate has a thickness less than 20 microns.