Probe for testing a device under test

• US 20080048692A1
• Filed: 10/24/2007
• Published: 02/28/2008
• Est. Priority Date: 05/23/2002
• Status: Active Grant

• Current Assignee: FormFactor Incorporated
• Original Assignee: Cascade Microtech Incorporated (FormFactor Incorporated)
• Inventors: Safwat, Amr, Andrews, Mike, Martin, John, Lesher, Tim, Dunklee, John, Hayden, Leonard, Strid, Eric, Gleason, K.
• Granted Patent: US 7,436,194 B2
• Time in Patent Office: Days
• US Class Current: 324/754
• CPC Class Codes: G01R 1/06711 Probe needles; Cantilever beams; "Bump" contacts; Replaceable probe pins
• CPC Class Codes: G01R 1/06755 Material aspects
• CPC Class Codes: G01R 1/06772 High frequency probes
• CPC Class Codes: G01R 1/06777 High voltage probes

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 supporting an elongate conductor on said substrate and a conductive member supported on said substrate;

(b) a contact electrically interconnected to said conductive path for testing a device under test;

(c) wherein said elongate conductor and said conductive member form a controlled impedance structure;

(d) wherein said probe has a characteristic that its contact resistance on un-patterned aluminum is generally less than 30 mΩ

over 5000 contact cycles.

2. The probe of claim 1 further comprising a flexible structure interconnected with said dielectric substrate, and a pre-loading mechanism that pre-loads said flexible structure with a force when said contact is free from being engaged with said device under test in such a manner that when force is applied to said probe it has a non-linear vertical deformation profile versus force applied.

3. The probe of claim 1 further comprising a conductive path between said first side of said substrate and said second side of said substrate.

4. The probe of claim 1 wherein said controlled impedance structure is a microstrip.

5. The probe of claim 2 wherein said flexible structure is a co-axial cable.

6. The probe of claim 1 herein said substrate has a thickness of less than 40 microns with a dielectric constant of less than 7.

7. The probe of claim 3 wherein said conductive path is in a region within the periphery of said substrate for at least a majority of the thickness of said substrate.

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

9. The probe of claim 1 wherein said conductive member is electrically connected to a conductor surrounding said central conductor of said coaxial cable.

10. The probe of claim 1 wherein said contact resistance is generally less than 5 mΩ

over said 5000 cycles.

11. A probe comprising:

(a) a dielectric substrate supporting an elongate conductor on said substrate and a conductive member supported on said substrate;

(b) a contact electrically interconnected to said conductive path for testing a device under test;

(c) wherein said elongate conductor and said conductive member form a controlled impedance structure;

(d) wherein said probe has a characteristic that its contact resistance on un-patterned aluminum is generally less than 35 mΩ

over a 5 hour time period.

12. The probe of claim 11 wherein said contact resistance is generally less than 10 mΩ

over said 5 hour time period.

13. The probe of claim 11 wherein said contact resistance has generally less than 10 mΩ

of variation over said 5 hour time period.

14. The probe of claim 11 further comprising a flexible structure interconnected with said dielectric substrate, and a pre-loading mechanism that pre-loads said flexible structure with a force when said contact is free from being engaged with said device under test in such a manner that when force is applied to said probe it has a non-linear vertical deformation profile versus force applied.

15. The probe of claim 11 further comprising a conductive path between said first side of said substrate and said second side of said substrate.

16. The probe of claim 11 wherein said controlled impedance structure is a microstrip.

17. The probe of claim 14 wherein said flexible structure is a co-axial cable.

18. The probe of claim 11 herein said substrate has a thickness of less than 40 microns with a dielectric constant of less than 7.

19. The probe of claim 15 wherein said conductive path is in a region within the periphery of said substrate for at least a majority of the thickness of said substrate.

20. The probe of claim 11 wherein an elongate conductor is electrically interconnected to a central conductor of a coaxial cable.

21. The probe of claim 11 wherein said conductive member is electrically connected to a conductor surrounding said central conductor of said coaxial cable.