The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 01, 1997
Filed:
Jun. 07, 1996
January Kister, Menlo Park, CA (US);
Probe Technology, Santa Clara, CA (US);
Abstract
This invention presents a method and a mechanism for contacting a set of vertical probes of a circuit testing mechanism with a set of pads or bumps of a circuit under test. The vertical probes have a circular cross section, a tip portion of length L1 and a beam portion of length L2, such that the beam portion extends at a right angle to the tip portion. The tip portion is guided through a guide hole to the pads of the circuit under test and the beam portion secured by its end. In this geometry the contact force between the probe and the pad is described by the relation: ##EQU1## where D.sub.v is a vertical deflection of the probe, I is an area moment of inertia of the probe about its axis, and E is a Young's modulus of the probe. The tip length L1 and beam length L2 are selected for each of the vertical probes in such a way the contact force F in this relation is kept constant thus ensuring that the contact force F between the vertical probes and pads remains substantially equal.