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:
Aug. 28, 2001
Filed:
Aug. 09, 1999
Sony Corporation, Tokyo, JP;
Abstract
A polishing wheel is pushed up and down in the Z-axis direction owing to a wafer surface shape. And the polishing amount depends on the height of protrusions on a wafer surface. Where a spindle is a rigid body in the Z-axis direction, the pressing force of the polishing wheel caused by vertical movement of a tool varies depending on the position on a wafer and hence polishing is not performed uniformly. To solve this problem, the spindle is provided with a Z-axis parallel leaf spring mechanism. Push-up and push-down actions of the polishing wheel are absorbed by displacement of the parallel leaf spring mechanism. This enables uniform polishing. Since the tool can be hardened, the flatness can also be improved.