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:
Mar. 20, 2018
Filed:
Apr. 06, 2015
Ebara Corporation, Tokyo, JP;
EBARA CORPORATION, Tokyo, JP;
Abstract
The invention simplifies airbag calibration. A pressure calibration jig calibrates pressure to be applied to a plurality of airbags disposed inside a top ring for holding and pressing a wafer against a polishing pad. The pressure calibration jig includes a plurality of first passages capable of communicating with the plurality of airbags, respectively; a second passage which combines and connects the plurality of first passages to a pressure calibration sensor; and a flow control portion configured to allow a fluid to flow through the first passage of the plurality of first passages, which first passage corresponds to an airbag selected for pressure calibration, in a direction from the selected airbag toward the second passage, and also configured to prevent the fluid from flowing through the first passages other than the first passage corresponding to the selected airbag in a direction from the second passage toward the airbags.