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. 07, 1998
Filed:
Nov. 29, 1995
Yoneta Tanaka, Yokohama, JP;
Ushiodenki Kabushiki Kaisha, Tokyo, JP;
Abstract
A process and apparatus for positioning a mask relative to a workpiece in which the relative positions of the alignment marks of the alignment mark of the mask and the workpiece can be easily recognized are achieved according to the invention by the fact that alignment light is emitted onto the mask alignment marks, projected images of the alignment marks of the mask are recorded by alignment units and undergo image processing, the relative positions are determined and stored, then emission of alignment light is stopped, alignment light is then emitted onto the alignment marks of the workpiece from the partial illumination systems, the alignment marks of the workpiece are recorded and undergo image processing, the relative positions thereof are determined and stored, data of the relative positions of the alignment marks of the mask and workpiece are computed, and relative movement of the workpiece and the mask is produced to position the two alignment marks one on top of the other.