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. 07, 2000
Filed:
Nov. 19, 1998
Applicant:
Inventors:
Marc A Christman, Vancouver, WA (US);
Robert O Mosier, Vancouver, WA (US);
Assignee:
Heraeus Shin-Etsu America, Camus, WA (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C30B / ;
U.S. Cl.
CPC ...
117208 ; 117900 ; 65 173 ; 65 174 ; 65 71 ; 65144 ; 65302 ;
Abstract
Methods and apparatus for manufacturing silica crucibles 9 containing few, if any, white point defects. The white point defects are reduced by decreasing the amount of silica vapor condensing on electrodes 4,5,6 used in the manufacturing process. The silica vapor condensation is decreased by providing a flow of a protective or non-reactive gas or gas mixture through protective devices 11,12,13, over portions of the electrodes where the silica vapor would otherwise condense.