Method of evaluating signal conditions in a probe measurement network having a plurality of separate measurement channels

• US 5,659,255 A
• Filed: 06/26/1996
• Issued: 08/19/1997
• Est. Priority Date: 04/14/1995
• Status: Expired due to Term

• Current Assignee: Cascade Microtech Incorporated (FormFactor Incorporated)
• Original Assignee: Cascade Microtech Incorporated (FormFactor Incorporated)
• Inventors: Gleason, K. Reed, Strid, Eric W., Schappacher, Jerry B., Carlton, Dale E.
• Primary Examiner(s): Nguyen, Vinh P.
• Application Number:
  US08/669,097
• Time in Patent Office: 419 Days
• Field of Search: 324/754, 324/158.1, 324/73.1, 324/755, 333/246, 333/248, 439/482, 439/824
• US Class Current: 324/750.02
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: G01R 1/06705 Apparatus for holding or moving single probes for moving multiple probe heads or ICs under test G01R31/2886
• CPC Class Codes: G01R 1/06772 High frequency probes
• CPC Class Codes: G01R 1/073 Multiple probes
• 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 35/00 Testing or calibrating of apparatus covered by the other groups of this subclass
• CPC Class Codes: G01R 35/005 Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references G01R33/0035, G01R35/002 take precedence

Abstract

A method of evaluating the signal conditions in a probe measurement network of the type having a plurality of separate measurement channels, where each channel communicates through a corresponding device-probing end. The method includes providing an assembly which includes a conductive planar probing area on the upper face of a base and a reference junction connected to the probing area by a high-frequency transmission structure. The method further includes placing the respective device-probing end of a first one of the measurement channels into contact with the planar probing area, transmitting a high-frequency signal through both the measurement channel and the reference junction and, thereafter, measuring the signal. This step is repeated for the other measurement channels and the signal conditions in the different channels are then evaluated by comparing the measured signals, where such evaluation is facilitated by maintaining, via the high-frequency transmission structure, a transmission line of substantially constant high-frequency transmission characteristic between each device-probing end coming into contact with the planar probing area and the reference junction.

Claims

1. A method for evaluating signal conditions in a probe measurement network of the type having a plurality of separate measurement channels, each measurement channel communicating through a corresponding device-probing end included on a probe tip array, said method comprising:

(a) providing an interconnect assembly including a base having an upper face, a conductive planar probing area on said upper face, and a reference junction, said reference junction being connected to said conductive planar probing area by a high-frequency transmission structure;

(b) placing the respective device-probing end of a first one of said measurement channels into contact with said planar probing area, transmitting a high-frequency signal through said first one of said measurement channels and said reference junction and, thereafter, measuring said signal;

(c) consecutively repeating step (b) for the other said measurement channels; and

(d) evaluating the relative signal conditions in the different ones of said measurement channels by comparing the measured signals, including facilitating such evaluation by providing, via said high-frequency transmission structure, a transmission line of substantially constant high-frequency transmission characteristic between each device-probing end coming into contact with said planar probing area said said reference junction.

2. The method of claim 1 including connecting a reference sensing unit to said reference junction, transmitting each signal from a different sourcing unit within said probe measurement network and measuring each signal at said reference sensing unit.

3. The method of claim 2 including adjusting said measured signals until said measured signals are substantially identical.

4. The method of claim 1 including connecting a reference sourcing unit to said reference junction, transmitting each signal from said reference sourcing unit and measuring each signal at a different sensing unit within said probe measurement network.

5. The method of claim 4 further including adjusting each sensing unit until said measured signals are substantially identical.

6. The method of claim 1 including transmitting said signal through said first one of said measurement channels before transmitting said signal through said reference junction.

7. The method of claim 1 including calibrating said probe measurement network by adjusting said measured signals.

8. The method of claim 1 including calibrating said probe measurement network by computationally compensating for the differences between said measured signals.

9. The method of claim 1 including, in step (a), providing a second conductive planar probing area on said upper face in spaced-apart adjacent relationship to the first said conductive planar probing area and further including, in step (b), simultaneously placing each of the device-probing ends that are out of contact with said first conductive planar probing area into contact with said second conductive planar probing area.

10. The method of claim 1 including providing an X-Y-Z positioning mechanism, bringing said device-probing ends into contact with different devices by means of said X-Y-Z positioning mechanism and also bringing different ones of said device-probing ends into contact with said conductive planar probing area by using said X-Y-Z positioning mechanism.