Probe station with low noise characteristics

• US 7,550,984 B2
• Filed: 10/04/2007
• Issued: 06/23/2009
• Est. Priority Date: 11/08/2002
• Status: Expired due to Fees

• Current Assignee: Cascade Microtech Incorporated (FormFactor Incorporated)
• Original Assignee: Cascade Microtech Incorporated (FormFactor Incorporated)
• Inventors: Miller, Brad, Lesher, Timothy, McDonald, Cynthia L., Gray, Frank, Simmons, Michael, Cowan, Clarence E.
• Primary Examiner(s): Nguyen; Vinh P
• Application Number:
  US11/906,846
• Publication Number:
  US 20080054922A1
• Time in Patent Office: 628 Days
• Field of Search: None
• US Class Current: 324/755.11
• CPC Class Codes: G01R 1/18 Screening arrangements against electric or magnetic fields, e.g. against earth's field
• CPC Class Codes: G01R 19/0053 Noise discrimination; Analog sampling; Measuring transients measuring characteristics of individual pulses G01R29/02; digital sampling G01R19/2509; measuring noise figure G01R29/26
• 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
• CPC Class Codes: G01R 31/2889 Interfaces, e.g. between probe and tester G01R31/31905 and G01R1/07364 take precedence
• CPC Class Codes: H01B 11/206 Tri-conductor coaxial cables

Abstract

A cable includes an inner conductor, an inner dielectric, and a guard conductor, where the inner dielectric is between the inner conductor and the guard conductor. The cable also includes an outer dielectric, and a shield conductor, where the outer dielectric is between the guard conductor and the shield conductor. The cable further includes an additional layer of material between the outer dielectric and the shield conductor of suitable composition for reducing triboelectric current generation between the outer dielectric and the shield conductor to less than that which would occur were the outer dielectric and the shield conductor to directly adjoin each other.

Claims

1. A probe station for probing a device under test comprising:

(a) a support for holding said device under test;

(b) a probing device for testing said device under test while being supported by said support;

(c) a cable connecting said probing device to a test instrument, said cable including;

(i) a first conductor, a first dielectric, and a second conductor, where said first dielectric is between said first conductor and said second conductor;

(ii) a second dielectric, and a third conductor, where said second dielectric is between said second conductor and said third conductor;

(iii) where triboelectric current between said second and third conductors exhibits a decay time between approximately one second and five seconds to decay to 10% of its initial value.

2. The probe station of claim 1 where triboelectric current between said first and second conductors exhibits a decay time between approximately one second and five seconds to decay to 10% of its initial value.

3. A probe station for probing a device under test comprising:

(a) a support for holding said device under test;

(b) a probing device for testing said device under test while being supported by said support;

(c) a cable connecting said probing device to a test instrument, said cable including;

(i) a first conductor, a first dielectric, and a second conductor, where said first dielectric is between said first conductor and said second conductor;

(ii) a second dielectric, and a third conductor, where said second dielectric is between said second conductor and said third conductor;

(iii) further including a first layer of material between said second dielectric and said second conductor of suitable composition for causing triboelectric current in said cable to exhibit a decay time between approximately one second and five seconds to decay to 10% of its initial value.

4. The probe station of claim 3 further comprising a second layer of material between said first dielectric and said second conductor.

5. A cable comprising:

(a) a first conductor, a first dielectric, and a second conductor, where said first dielectric is between said first conductor and said second conductor;

(b) a second dielectric, and a third conductor, where said second dielectric is between said second conductor and said third conductor;

(c) where triboelectric current between said second and third conductors exhibits a decay time between approximately one second and five seconds to decay to 10% of its initial value.

6. The cable of claim 5 where triboelectric current between said first and second conductor exhibits a decay time between approximately one second to five seconds to decay to 10% of its initial value.

7. A cable comprising:

(a) a first conductor, a first dielectric, and a second conductor, where said first dielectric is between said first conductor and said second conductor;

where

(b) where triboelectric current between said first and second conductors exhibits a decay time between approximately one second and five seconds to decay to 10% of its initial value.