Making discrete power connections to a space transformer of a probe card assembly

• US 6,050,829 A
• Filed: 08/28/1997
• Issued: 04/18/2000
• Est. Priority Date: 08/28/1996
• Status: Expired due to Term

• Current Assignee: FormFactor Incorporated
• Original Assignee: FormFactor Incorporated
• Inventors: Mathieu, Gaetan L., Eldridge, Benjamin N., Grube, Gary W., Khandros, Igor Y.
• Primary Examiner(s): Abrams, Neil
• Application Number:
  US08/920,255
• Time in Patent Office: 964 Days
• Field of Search: 439/66, 439/67, 324/754, 324/761
• US Class Current: 439/67
• CPC Class Codes: G01R 1/07378 using an intermediate adapter, e.g. space transformers G01R1/07371 takes precedence

Abstract

By segregating at least a substantial portion of the power connections to the space transformer component (506, 700, 800) from the signal connections thereto, constraints on the interposer component (504) may be relaxed. This is particularly advantageous in the context of probing one or more high power semiconductor components. The technique of the present invention provides for a plurality of signals (including power and ground) to be inserted into an electronic component such as a space transformer both from a one main surface thereof and an edge (periphery) thereof to an opposite main surface thereof. The space transformer includes pads (522, 706, 810) for engaging, by means of spring elements (524), component (508) to be tested and includes exposed edge pads (750, 804, 854) for engagement by a flexible cable (752) for transmission of power and ground signals to the space transformer. The system also includes an interposer (504) having resilient contacts (514, 516) for electrically interconnecting a probe card (502) to the space transformer (506).

Claims

1. A space transformer for a probe card assembly, comprising:

a space transformer having a first surface, a second surface, and a side edge, the side edge distinct from the first surface and distinct from the second surface;

a first plurality of terminals disposed on the first surface of the space transformer;

a second plurality of terminals disposed on the second surface of the space transformer and connected within the space transformer to a first portion of the first plurality of terminals; and

a third plurality of terminals disposed along the side edge of the space transformer and connected within the space transformer to a second portion of the first plurality of terminals and not connected to the second plurality of terminals, and with no corresponding connection to the first portion of the first plurality of terminals.

2. A probe card assembly, comprising:

a probe card having a top surface, a bottom surface and a plurality of contact terminals on the top surface thereof;

an interposer having a top surface, a bottom surface, a first plurality of resilient contact structures extending from the bottom surface thereof and a second plurality of contact structures extending from the top surface thereof; and

a space transformer having a first surface, a second surface, and a side edge, the side edge distinct from the first surface and distinct from the second surface;

a first plurality of terminals disposed on the first surface of the space transformer;

a second plurality of terminals disposed on the second surface of the space transformer and connected within the space transformer to a first portion of the first plurality of terminals; and

a third plurality of terminals disposed along the side edge of the space transformer and connected within the space transformer to a second portion of the first plurality of terminals and not connected to the second plurality of terminals, and with no corresponding connection to the first portion of the first plurality of terminals;

wherein;

the first plurality of resilient contact structures effect a pressure connection with the contact terminals of the probe card; and

the second plurality of resilient contact structures effect a pressure connection with the second plurality of terminals on the bottom surface of the space transformer.

3. A space transformer for a probe card assembly, comprising:

a space transformer having a first surface, a second surface, and a side edge, the side edge distinct from the first surface and distinct from the second surface;

a first plurality of terminals disposed on the first surface of the space transformer;

a plurality of resilient contact elements connected to selected ones of the first plurality of terminals disposed on the first surface;

a second plurality of terminals disposed on the second surface of the space transformer and connected within the space transformer to a first portion of the first plurality of terminals; and

a third plurality of terminals disposed along the side edge of the space transformer and connected within the space transformer to a second portion of the first plurality of terminals and not connected to the second plurality of terminals.