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. 01, 2003
Filed:
Oct. 04, 2000
Applicant:
Inventors:
Kiyoshi Araki, Nagoya, JP;
Tsuneaki Ohashi, Ogaki, JP;
Katsuhiro Inoue, Ama-Gun, JP;
Masaaki Masuda, Nagoya, JP;
Assignee:
NGK Insulators, Ltd., Nagoya, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C04B 3/5587 ;
U.S. Cl.
CPC ...
C04B 3/5587 ;
Abstract
A silicon nitride sintered material includes a polycrystal material having silicon nitride crystal grains and a grain boundary phase. The sintered material contains a Yb element in an amount of 2 to 30% by weight in terms of its oxide and an Al element in an amount of 1 to 20% by weight in terms of its oxide and has a thermal conductivity of 40 W/mK or less at room temperature, a resistivity of 1×10 to 1×10 &OHgr;·cm at room temperature, and a porosity of 0.5% or less.