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:
Oct. 22, 1996
Filed:
Sep. 21, 1994
Anton Huber, Burghausen, DE;
Robert Weiss, Winhoring, DE;
Wacker-Chemitronic Gesellschaft fur Elektronik-Grundstoffe AG, Burghausen, DE;
Abstract
A workpiece holder for rotary grinding machines for grinding semiconductor afers has a rotatable work surface which points toward a rotating grinding tool and on which the semiconductor wafer to be machined is laid, and has piezoelectric elements on which the workpiece holder is axially supported. The piezoelectric elements can be operated independently of one another and, when operated, undergo a change in their linear dimension, an operated piezoelectric element axially raising or lowering the workpiece holder at the point at which it supports the workpiece holder. There is also a method for positioning the workpiece holder.