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:
May. 02, 1995
Filed:
Jul. 01, 1993
Terri Giversen, Beverly, MA (US);
Mark Stratton, Ottawa, GA (US);
Nile F Hartman, Stone Mountain, GA (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
The present invention is a method and an apparatus for the precise quantitative measurement of the magnitude of force exerted at the points of contact on a high density electrical interconnect that quantitatively determines the magnitude of the force. The invention includes the steps of establishing a pressing relationship between a photoelastic material and the high density interconnect, coupling plane-polarized light into the photoelastic material stressed as a result of the pressing relationship with the high density interconnect, coupling of the polarized light being at 45 degrees with the direction of pressing, capturing an image of the fringe pattern of the plane polarized light exiting the stressed photoelastic material, the fringe pattern comprising of fringes wherein the number of fringes varies with the magnitude of the pressing force, and counting the number of fringes produced to determine the magnitude of force exerted on the photoelastic member.