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:
Jan. 13, 1998
Filed:
Apr. 24, 1996
Tsutomu Sahoda, Kanagawa, JP;
Koji Ueda, Kanagawa, JP;
Hidenori Miyamoto, Kanagawa, JP;
Toru Arikawa, Kanagawa, JP;
Tokyo Ohka Kogyo Co., Ltd., Kanagawa, JP;
Abstract
When a carrier arm is retracted, a semiconductor wafer carried thereon passes between three light-emitting elements and three light-detecting elements associated therewith. At this time, a controller determines six points on the outer circumferential edge of the semiconductor wafer based on signals from sensors made up of the light-emitting elements and the light-detecting elements. The controller selects three of the determined points, determines the center of a circumscribed circle passing through the selected three points, and regards the determined center as the center of the semiconductor wafer. Then, the controller controls movement of the semiconductor wafer toward a rotary-cup coating device, an evacuating drying device, or an edge cleaning device based on the center of the semiconductor wafer.