Methods and structures for electronic probing arrays

• US 6,876,212 B2
• Filed: 12/04/2003
• Issued: 04/05/2005
• Est. Priority Date: 07/07/1994
• Status: Expired due to Fees

• Current Assignee: Tesseva Incorporated
• Original Assignee: Tesseva Incorporated
• Inventors: Fjelstad, Joseph
• Primary Examiner(s): KARLSEN, ERNEST F
• Application Number:
  US10/728,308
• Publication Number:
  US 20040080328A1
• Time in Patent Office: 488 Days
• Field of Search: 324/754, 324/757, 324/758, 324/762, 324/765
• US Class Current: 324/754.07
• CPC Class Codes: G01R 1/0491 for testing integrated circuits on wafers, e.g. wafer-level test cartridge
• CPC Class Codes: G01R 1/06727 Cantilever beams
• CPC Class Codes: G01R 1/07342 the body of the probe being at an angle other than perpendicular to test object, e.g. probe card
• CPC Class Codes: G01R 3/00 Apparatus or processes specially adapted for the manufacture or maintenance of measuring instruments , e.g. of probe tips

Abstract

A probe card for testing an electrical element such as a semiconductor wafer or a printed wiring board includes a substrate with circuitry thereon, an encapsulant layer overlying the substrate and a multiplicity of leads extending upwardly from the substrate through the encapsulant layer to terminals, the terminals projecting above the encapsulant layer. The probe card can be engaged with the electronic element so that the tips of the leads bear on the contact pads of the electronic element, and so that the leads and encapsulant layer deform to accommodate irregularities in the electronic element or probe card. The card can be made by providing the substrate, a sacrificial layer and leads extending between the sacrificial layer and substrate, moving the substrate and sacrificial layer away from one another to deform the leads and injecting a curable material around the leads to form the encapsulant layer.

Claims

1. A probe card for testing electronic elements comprising:

(a) a substrate having an electrical circuitry thereon;

(b) an encapsulant layer overlying said substrate; and

(c) a plurality of flexible leads extending through said encapsulant layer, said plurality of flexible leads being permanently bonded to said electrical circuitry, said plurality of flexible leads having terminals projecting above said encapsulant layer and exposed for engagement with contact pads on a electronic element, said plurality of flexible leads having flexible portions disposed within said encapsulant layer.

2. The probe card as claimed in claim 1 wherein said terminals have sharp features.

3. The probe card as claimed in claim 2 wherein said terminals have points.

4. The probe card as claimed in claim 1 wherein said encapsulant layer has channels therein subdividing the encapsulant layer into a plurality of portions, said portions of said encapsulant layer being deformable independently of one another.

5. The probe card as claimed in claim 1 wherein said terminals are physically connected to one another solely by said encapsulant layer and said leads.

6. The probe card as claimed in claim 1 further comprising a flexible dielectric layer overlying said encapsulant layer, said flexible dielectric layer having a top surface facing away from said encapsulant layer and substrate, said terminals being attached to said flexible dielectric layer and exposed at the top surface of said flexible dielectric layer.

7. The probe card as claimed in claim 1 wherein at least some of said leads are multiconductor leads, each such multiconductor lead including a plurality of lead conductors and a dielectric material disposed between said lead conductors, said terminals including sets of plural closely-spaced terminals, at least some of said multiconductor leads being connected to said closely-spaced terminal sets so that the conductors on each such multiconductor lead are connected to terminals of the same set.