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:
Apr. 05, 2011
Filed:
Oct. 19, 2007
Frederick Schmid, Marblehead, MA (US);
Chandra P. Khattak, Danvers, MA (US);
David B. Joyce, Marblehead, MA (US);
Frederick Schmid, Marblehead, MA (US);
Chandra P. Khattak, Danvers, MA (US);
David B. Joyce, Marblehead, MA (US);
GT Crystal Systems, LLC, Salem, MA (US);
Abstract
To reduce the heat input to the bottom of the crucible and to control heat extraction independently of heat input, a shield can be raised between a heating element and a crucible at a controlled speed as the crystal grows. Other steps could include moving the crucible, but this process can avoid having to move the crucible. A temperature gradient is produced by shielding only a portion of the heating element; for example, the bottom portion of a cylindrical element can be shielded to cause heat transfer to be less in the bottom of the crucible than at the top, thereby causing a stabilizing temperature gradient in the crucible.