Probing apparatus with guarded signal traces

• US 8,203,351 B2
• Filed: 05/19/2010
• Issued: 06/19/2012
• Est. Priority Date: 07/08/2005
• Status: Expired due to Fees

• Current Assignee: FormFactor Incorporated
• Original Assignee: FormFactor Incorporated
• Inventors: Eldridge, Benjamin N., Reynolds, Carl V., Saeki, Takao, Urakawa, Yoichi
• Primary Examiner(s): Velez, Roberto
• Assistant Examiner(s): Nguyen, Tung X
• Application Number:
  US12/782,904
• Publication Number:
  US 20100225344A1
• Time in Patent Office: 762 Days
• Field of Search: 32475401-75429, 32476201-76209, 32475507-75509, 32475702-75705, 257/48, 438 14- 18
• US Class Current: 324/754.01
• 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 1/18 Screening arrangements against electric or magnetic fields, e.g. against earth's field
• CPC Class Codes: G01R 31/2889 Interfaces, e.g. between probe and tester G01R31/31905 and G01R1/07364 take precedence

Abstract

A probing apparatus can comprise a substrate, conductive signal traces, probes, and electromagnetic shielding. The substrate can have a first surface and a second surface opposite the first surface, and the electrically conductive first signal traces can be disposed on the first surface of the first substrate. The probes can be attached to the first signal traces, and the electromagnetic shielding structures can be disposed about the signal traces.

Claims

1. A probing apparatus comprising:

a plurality of substrates;

a plurality of probes disposed on at least a first one of the plurality of substrates;

an electrical interface to a source of test signals, the electrical interface disposed on at least a second one of the plurality of substrates;

a plurality of electrical connections electrically connecting the electrical interface to ones of the plurality of probes; and

wherein each of ones of the plurality of electrical connections comprises;

an electrically conductive signal trace disposed on a first level of one of the plurality of substrates, and

a plurality of electromagnetic shielding structures disposed proximate to the signal trace on the first level, on a second level that is different than the first level, and on a third level that is different than the first level and the second level,

wherein;

the signal trace is disposed between ones of the shielding structures on the first level, and

the signal trace is disposed between one of the shielding structures on the second level and one of the shielding structures on the third level.

2. The probing apparatus of claim 1, wherein the first level is an interior level of the one of the plurality of substrates.

3. The probing apparatus of claim 1, wherein:

one of the electromagnetic shielding structures comprises a first guard trace on the second level, and one of the electromagnetic shielding structures comprises a second guard trace on the third level of the one of the plurality of substrates.

4. The probing apparatus of claim 3, wherein a plurality of the signal traces are disposed between the first guard trace and the second guard trace.

5. The probing apparatus of claim 1, wherein ones of the electrical connections comprise a flexible connection.

6. The probing apparatus of claim 5, wherein the flexible connection comprises an electromagnetically shielded wire.

7. The probing apparatus of claim 1, wherein the probes are electromagnetically unshielded.

8. The probing apparatus of claim 1, wherein the electromagnetic shielding structures include:

a first guard trace and a second guard trace disposed on the first level, wherein the signal trace is disposed between the first guard trace and the second guard trace;

a first guard plate disposed on the second level; and

a second guard plate disposed on the third level,

wherein the signal trace is between the first guard plate and the second guard plate.

9. The probing apparatus of claim 8 further comprising electrical insulating material disposed between the signal trace and each of the first guard trace, the second guard trace, the first guard plate, and the second guard plate.

10. The probing apparatus of claim 1, wherein the electromagnetic shielding structures form a box structure enclosing the signal trace.

11. The probing apparatus of claim 10, wherein the box structure comprises:

a first one of the shielding structures disposed on the second level,

a second one of the shielding structures disposed on the third level,

a third one of the shielding structures passing through the first level and electrically connecting the first one of the shielding structures and the second one of the shielding structures, and

a fourth one of the shielding structures passing through the first level and electrically connecting the first one of the shielding structures and the second one of the shielding structures,

wherein the signal trace is disposed between the first one of the shielding structures and the second one of the shielding structures and between the third one of the shielding structures and the fourth one of the shielding structures.

12. The probing apparatus of claim 1, wherein each of at least some of the ones of the plurality of electrical connections comprises:

an electrically conductive second signal trace on or in another of the plurality of the substrates, and

a guard structure on or in the another of the plurality of substrates disposed adjacent the second signal trace.

13. The probing apparatus of claim 12, wherein the signal trace on the first level of the one of the plurality of substrates is electrically connected to the second signal trace on or in the another of the plurality of substrates.

14. A probing apparatus comprising:

a plurality of substrates;

a plurality of probes disposed on at least a first one of the plurality of substrates;

an electrical interface to a source of test signals, the electrical interface disposed on at least a second one of the plurality of substrates;

a plurality of electrical connections electrically connecting the electrical interface to ones of the plurality of probes; and

wherein the plurality of electrical connections comprise;

a plurality of electrically conductive signal traces disposed on a first level of ones of the plurality of substrates, and

a plurality of electromagnetic shielding structures disposed proximate to the signal traces, wherein ones of the electromagnetic shielding structures comprise a first guard trace on a second level of the ones of the plurality of substrates, the second level being a different level than the first level,

wherein ones of the electromagnetic shielding structures comprise a second guard trace on a third level of the ones of the plurality of substrates, the third level being a different level than each of the first level and the second level, and

wherein the ones of the electromagnetic shielding structures comprise electrical connections between the first guard trace and the second guard trace to form a box around the signal trace.

15. The probing apparatus of claim 14, wherein multiple ones of the signal traces are at least partially enclosed by the box.

16. A probing apparatus comprising:

a plurality of substrates;

a plurality of probes disposed on at least a first one of the plurality of substrates;

an electrical interface to a source of test signals, the electrical interface disposed on at least a second one of the plurality of substrates;

a plurality of electrical connections electrically connecting the electrical interface to ones of the plurality of probes; and

wherein the plurality of electrical connections comprise;

a plurality of electrically conductive signal traces disposed on a first level of ones of the plurality of substrates, and

a plurality of electromagnetic shielding structures disposed proximate to the signal traces, wherein ones of the electromagnetic shielding structures comprise a first guard trace on a second level of the ones of the plurality of substrates, the second level being a different level than the first level,

wherein the electromagnetic shielding structure comprises a conductive box, wherein the first guard trace forms a side of the conductive box.

17. The probing apparatus of claim 16, wherein the conductive box comprises a cover, wherein the cover is disposed on a surface of the ones of the plurality of substrates.

18. A probing apparatus comprising:

a probe substrate;

a plurality of probes disposed on the probe substrate;

a wiring substrate;

an electrical interface to a source of test signals, the electrical interface disposed on the wiring substrate; and

a plurality of electrical connections electrically connecting the electrical interface through the wiring substrate and the probe substrate to ones of the plurality of probes,

wherein a portion of ones of the electrical connections comprise a first electromagnetically shielded trace on or in the wiring substrate electrically connected to a second electromagnetically shielded trace on or in the probe substrate,

wherein the first shielded trace comprises a first electrically conductive signal trace on or in the wiring substrate, and a first electrically conductive guard trace or plane disposed adjacent to the first signal trace on or in the wiring substrate, and

the second shielded trace comprises a second electrically conductive signal trace on or in the probe substrate and a second electrically conductive guard trace or plane disposed adjacent to the second signal trace on or in the probe substrate.

19. The probing apparatus of claim 18, wherein:

the second electrically conductive signal trace is disposed on a first level of the probe substrate; and

the second electrically conductive guard trace or plane is disposed on a second level of the probe substrate, the second level being different than the first level.

20. The probing apparatus of claim 18, wherein the first shielded trace is electrically connected to the second shielded trace by an electromagnetically shielded electrical connection.

21. A probing apparatus comprising:

a probe substrate;

a plurality of probes disposed on the probe substrate;

a wiring substrate;

an electrical interface to a source of test signals, the electrical interface disposed on the wiring substrate; and

a plurality of electrical connections electrically connecting the electrical interface to ones of the plurality of probes, wherein at least a portion of ones of the electrical connections is a shielded trace;

wherein the shielded trace comprises;

an electrically conductive signal trace; and

a first electrically conductive plane disposed adjacent to the signal trace, and

wherein the shielded trace further comprises;

a second electrically conductive plane disposed adjacent to the signal trace on an opposite site of the signal trace form the first electrically conductive plane,

the probing apparatus further comprising at least two electrically conductive signal traces disposed between the first electrically conductive plane and the second electrically conductive plane.

22. A probing apparatus comprising:

a probe substrate;

a plurality of probes disposed on the probe substrate;

a wiring substrate;

an electrical interface to a source of test signals, the electrical interface disposed on the wiring substrate; and

a plurality of electrical connections electrically connecting the electrical interface to ones of the plurality of probes, wherein at least a portion of ones of the electrical connections is a shielded trace;

wherein the shielded trace comprises;

an electrically conductive signal trace; and

a first electrically conductive plane disposed adjacent to the signal trace, and

wherein the shielded trace further comprises;

a second electrically conductive plane disposed adjacent to the signal trace on an opposite site of the signal trace form the first electrically conductive plane, and

wherein;

the first electrically conductive plane and the second electrically conductive plane are electrically connected to form a conductive box surrounding the electrically conductive signal trace.