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:
Feb. 23, 1999
Filed:
Oct. 21, 1996
Yoneta Tanaka, Yokohama, JP;
Ushiodenki Kabushiki Kaisha, Tokyo, JP;
Abstract
A process for projection exposure in which, using alignment marks on the back of a workpiece, positioning of the mask to the workpiece is performed, and a device for executing the process is achieved by the fact that exposure light is emitted from an exposure light irradiation device without the workpiece being in place. Images of alignment marks of the mask are imaged on image sensors of alignment units, and by an image processing part positions thereof are determined. According to the invention, then, a workpiece is placed on a workpiece carrier, light is emitted from alignment light irradiation devices and positions of the alignment marks of the workpiece are determined. Furthermore, the workpiece carrier is moved by the carrier drive device such that the alignment marks of the mask and workpiece come to rest on top of one another, and thus positioning of the mask to the workpiece is done. Then the exposure surface of the workpiece and the imaging position of the mask are brought into agreement with one another, exposure light is emitted from the exposure light irradiation device, and the workpiece is exposed.