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. 18, 2006
Filed:
Apr. 15, 2003
Sean J. Kirkpatrick, Portland, OR (US);
Donald D. Duncan, Silver Spring, MD (US);
Sean J. Kirkpatrick, Portland, OR (US);
Donald D. Duncan, Silver Spring, MD (US);
Providence Health System, Portland, OR (US);
Abstract
Methods for measuring strains in circuit substrates such as circuit boards and semiconductor wafers include illuminating a specimen with a substantially collimated laser flux. A temperature change is produced in the specimen and a series of laser speckle patterns produced by a laser flux scattered or reflected by the specimen is recorded. Localized strains are detected based on speckle pattern shifts that are calculated using the recorded speckle patterns. Stains can be recorded as a function of temperature or rate of change of temperature, and strains at one or more circuit substrate locations can be detected.