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. 26, 1998
Filed:
Apr. 04, 1996
Isaac T Poku, Austin, TX (US);
Rama Cherkur, Cedar Park, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A method for determining the cleanliness of a surface of a substrate involves using a visual pattern (17, 29). The visual pattern is either provided in the optical portion of a visual system or is formed on the surface of the substrate to be analyzed. A liquid droplet (26, 27) is dispensed onto the substrate surface, and the extent of the spread area of the droplet is compared to the visual pattern. If the area of the droplet is greater than or equal to a tolerance as signified by the pattern markings, then the surface of the substrate is determined to be sufficiently clean. In relying upon a simple visual comparison of the area of the surface covered by the droplet with an empirically determined visual pattern, a method for analyzing surface cleanliness is consistent between operators and surfaces, is easy to set up and operate, and improves manufacturing throughput.