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:
Jan. 10, 2012
Filed:
Jan. 09, 2009
Tadahiro Sato, Akita, JP;
Masaki Morikawa, Akita, JP;
Tadahiro Sato, Akita, JP;
Masaki Morikawa, Akita, JP;
Japan Super Quartz Corporation, Akita-Ken, JP;
Abstract
The disclosed is a method of manufacturing a silica glass crucible for pulling silicon single crystals. In the method, reduced pressure is imparted from the inner surface to the outer surface of a crucible-shaped molded product and the crucible-shaped molded product is arc-fused while rotating the same to form a silica glass crucible with a transparent layer on the inner surface side and a bubble layer on the outer surface side. The inner surface of the wall portion of the silica glass crucible is fused a second time by arc fusion to cause bubbles present in the transparent layer of the inner surface of the wall portion to be displaced toward the bottom portion of the inner surface of the wall portion. The inner surface of the bottom portion of the silica glass crucible is fuse a second time by arc fusion to cause bubbles present in the transparent layer of the inner surface of the bottom portion to be displaced toward the periphery of the inner surface of the bottom portion. Either the step of displacement toward the bottom portion or the step of displacement toward the outer periphery is inverted first.