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:
Nov. 17, 2015
Filed:
Jul. 28, 2010
Toshiaki Sudo, Akita, JP;
Masaru Sato, Akita, JP;
Toshiaki Sudo, Akita, JP;
Masaru Sato, Akita, JP;
Japan Super Quartz Corporation, Akita-shi, JP;
Abstract
A vitreous silica crucible has high strength at high temperature, and allows easy taking-out from a susceptor after completion of pulling. The vitreous silica crucible includes a vitreous silica outer layer provided on the outer surface side of the crucible, a vitreous silica inner layer provided on the inner surface side of the crucible, and an vitreous silica intermediate layer provided between the vitreous silica outer layer and the vitreous silica inner layer. The vitreous silica outer layer has a mineralizer concentration of 100 ppm or more, and the vitreous silica intermediate layer and the vitreous silica inner layer has a mineralizer concentration of 50 ppm or less. The thickness of the vitreous silica outer layer is 0.5 mm to 2.0 mm on the bottom portion, and the thickness on the sidewall portion of the vitreous silica outer layer is larger than that on the bottom portion.