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:
Nov. 03, 1998
Filed:
Jan. 11, 1994
Applicant:
Inventor:
Roger G Hine, San Francisco, CA (US);
Assignee:
Hine Design Inc., Redwood City, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01B / ;
U.S. Cl.
CPC ...
356399 ; 356401 ; 359390 ;
Abstract
Apparatus and method for reading an identification mark on a semi-conductor wafer. The wafer includes a marking area which bears a relief mark. The marking area is illuminated by a segmented light source and is viewed by a viewing device. The viewing device sees a dark segment and an adjacent lighted segment which preferably surrounds the dark segment, and the mark appears as a light image in the dark segment. Preferably the segmented light source is a diffuse light source with an opaque patch at its center. The method is particularly effective for reading soft marks with low profiles.