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. 14, 2012
Filed:
Mar. 14, 2008
Georg Pietsch, Burghausen, DE;
Michael Kerstan, Burghausen, DE;
Heiko Aus Dem Spring, Hamburg, DE;
Siltronic AG, Munich, DE;
Peter Wolters GmbH, Rendsburg, DE;
Abstract
Simultaneous double-side grinding of a plurality of semiconductor wafers involves positioning each wafer freely in a cutout of one of plural carriers which rotate on a cycloidal trajectory, wherein the wafers are machined between two rotating ring-shaped working disks, each disk having a working layer of bonded abrasive, wherein the form of the working gap between working layers is determined during grinding and the form of the working area of at least one disk is altered such that the gap has a predetermined form. The wafers, during machining, may temporarily overhang the gap. The carrier is optionally composed only of a first material, or is completely or partly coated with the first material such that during machining only the first material contacts the working layer, and the first material does not reduce the machining ability of the working layer.