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. 11, 2020
Filed:
Jun. 07, 2016
Applicant:
Shin-etsu Chemical Co., Ltd., Tokyo, JP;
Inventors:
Hisashi Yagi, Joetsu, JP;
Daijitsu Harada, Joetsu, JP;
Masaki Takeuchi, Joetsu, JP;
Kazuo Shirota, Joetsu, JP;
Kazuhiko Aoki, Joetsu, JP;
Assignee:
SHIN-ETSU CHEMICAL CO., LTD., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G03F 1/60 (2012.01); B05D 1/28 (2006.01); C03C 17/32 (2006.01); G01N 21/23 (2006.01); G03F 1/20 (2012.01);
U.S. Cl.
CPC ...
G03F 1/60 (2013.01); B05D 1/28 (2013.01); C03C 17/32 (2013.01); G01N 21/23 (2013.01); G03F 1/20 (2013.01);
Abstract
A synthetic quartz glass substrate is prepared by furnishing a synthetic quartz glass block, coating two opposite surfaces of the block with a liquid having a transmittance of at least 99.0%/mm at the wavelength of birefringence measurement, measuring a birefringence distribution on the block by letting light enter one coated surface and exit the other coated surface, and sorting the block to an acceptable group or unacceptable group, based on the measured birefringence distribution.