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. 20, 2024
Filed:
Jun. 14, 2022
Disco Corporation, Tokyo, JP;
DISCO CORPORATION, Tokyo, JP;
Abstract
A rotation controlling section of a control unit calculates a maximum thicknesswise difference in a wafer by using a noncontact thickness measuring instrument, and if the maximum thicknesswise difference exceeds a tolerance, relatively changes a rotational speed of a chuck table relative to a rotational speed of a spindle. This can shift a rotational speed ratio, which is a ratio between the rotational speed of the spindle and the rotational speed of the chuck table, from an integer. Therefore, the maximum thicknesswise difference can be made small through spark-out processing. As a result, cyclic variations in thickness value of the wafer are reduced, enabling planarization of a ground surface of the wafer.