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:
Jun. 05, 2007
Filed:
Apr. 03, 2003
Gabriele Korus, Leipzig, DE;
Martin Arndt, Bitterfeld, DE;
Hilmar Laudahn, Bitterfeld, DE;
Manfred Schwarzbauer, Simbach, DE;
Gabriele Korus, Leipzig, DE;
Martin Arndt, Bitterfeld, DE;
Hilmar Laudahn, Bitterfeld, DE;
Manfred Schwarzbauer, Simbach, DE;
Heraeus Quarzglas GmbH & Co. KG, Hanau, DE;
Siltronic AG, Munich, DE;
Abstract
A known quartz glass crucible for crystal pulling consists of a crucible wall, having an outer layer which is provided in an external area thereof with a crystallisation promoter which results in crystallisation of quartz glass, forming cristobalite when the quartz glass crucible is heated according to specified use in crystal pulling. The aim of the invention is to provide a quartz glass crucible which has a long service life. As a result, the crystallisation promoter contains, in addition to a silicon, a first component which acts as a reticulating agent in quartz glass and a second component which is free of alkali metals and which acts as an agent forming separating points in quartz glass. The above mentioned components are contained and incorporated into a doping area () of the outer layer () having a layer thickness of more than 0.2 mm.