Switched suspended conductor and connection

• US 20040222807A1
• Filed: 03/05/2004
• Published: 11/11/2004
• Est. Priority Date: 05/06/2003
• Status: Active Grant

• Current Assignee: Cascade Microtech Incorporated (FormFactor Incorporated)
• Original Assignee: Cascade Microtech Incorporated (FormFactor Incorporated)
• Inventors: Dunklee, John
• Granted Patent: US 7,221,172 B2
• Time in Patent Office: Days
• US Class Current: 324/754
• CPC Class Codes: G01R 31/2886 Features relating to contacting the IC under test, e.g. probe heads; chucks G01R31/2865 takes precedence, test connections, e.g. test sockets, or probes per se, G01R1/04 or G01R1/06

Abstract

A probe assembly having a switch that selectively electrically connects, for example, either a Kelvin connection or a suspended guard element with the probe assembly.

Claims

1. An assembly comprising:

(a) a support suitable to support a device-under-test;

(b) a first member defining a first electrical path to said device-under-test;

(c) a second member defining a second electrical path to said device-under-test;

(d) a conductive member vertically spaced apart from at least a portion of said device-under-test; and

(e) a switch mechanism that alternately electrically connects said second member to a test instrument while electrically isolating said conductive member from said test instrument, and electrically isolates said second member from said test instrument while electrically connects said conductive member to said test instrument.

2. The assembly of claim 1 wherein said conductive member is electrically connected to a guard potential.

3. The assembly of claim 1 wherein at least one of said first member and said second member is a cable.

4. The assembly of claim 1 wherein said first member and said second member form a Kelvin measurement.

5. The assembly of claim 1 wherein said first member and said second member form a quasi-Kelvin measurement.

6. The assembly of claim 4 wherein said second member is a sense connection.

7. The assembly of claim 5 wherein said second member is a sense connection.

8. The assembly of claim 1 wherein said isolating and said electrically connects is substantially simultaneous.

9. The assembly of claim 1 wherein at least a portion of said conductive member at least partially overlaps said support.

10. An assembly comprising:

(a) a support suitable to support a device-under-test;

(b) a first member defining a first electrical path to said device-unders-test;

(c) a conductive member vertically spaced apart from at least a portion of said device-under-test; and

(d) a switch mechanism that alternately electrically connects said first member to a test instrument while electrically isolating said conductive member from said test instrument, and electrically isolates said first member from said test instrument while electrically connects said conductive member to said test instrument.

11. The assembly of claim 10 wherein said conductive member is electrically connected to a guard potential.

12. The assembly of claim 10 wherein said first member is a cable.

13. The assembly of claim 10 wherein said first member is part of a Kelvin measurement.

14. The assembly of claim 10 wherein said first member is a part of a quasi-Kelvin measurement.

15. The assembly of claim 13 wherein said first member is a sense connection.

16. The assembly of claim 14 wherein said first member is a sense connection.

17. The assembly of claim 10 wherein said isolating and said electrically connects is substantially simultaneous.

18. The assembly of claim 10 wherein at least a portion of said conductive member at least partially overlaps said support.

19. An assembly comprising:

(a) a support suitable to support a device-under-test;

(b) a conductive member vertically spaced apart from at least a portion of said device-under-test; and

(c) a switch mechanism that alternately isolates said conductive member from said test instrument, and electrically connects said conductive member to said test instrument.

20. The assembly of claim 19 wherein said conductive member is electrically connected to a guard potential.

21. The assembly of claim 19 wherein at least a portion of said conductive member at least partially overlaps said support.