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:
Sep. 21, 2010
Filed:
Sep. 25, 2007
Applicants:
George C. Wei, Weston, MA (US);
Harry S. Mackel, Pepperell, MA (US);
Inventors:
George C. Wei, Weston, MA (US);
Harry S. Mackel, Pepperell, MA (US);
Assignee:
Osram Sylvania Inc., Danvers, MA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C04B 35/581 (2006.01); C04B 35/58 (2006.01); C04B 35/64 (2006.01);
U.S. Cl.
CPC ...
Abstract
The present method uses a methane-containing nitrogen gas sintering atmosphere to sinter aluminum nitride (AlN) to a high transmittance. The methane gas replaces the solid carbon charge material used in prior art sintering methods as the source of gaseous carbon. The amount of carbon in the methane-containing nitrogen gas is easily controlled by varying the partial pressure of methane in the nitrogen gas. In addition, the methane flow is stopped prior to the end of the sintering cycle to prevent darkening of the sintered part.