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:
May. 16, 2017
Filed:
Oct. 11, 2012
Hitachi Metals, Ltd., Tokyo, JP;
Youichirou Kaga, Kitakyushi, JP;
HITACHI METALS, LTD., Tokyo, JP;
Abstract
A silicon nitride substrate including a phase encompassed of silicon nitride particles, and intergranular phase formed from a sintering aid, wherein a separation layer is formed on the surface of a molded body including silicon nitride powder, sintering aid powder, and organic binder, by using a boron nitride paste containing boron nitride powder, organic binder, and organic solvent; the separation layer and molded body are heated; the organic binder is removed from the separation layer and molded body; subsequently molded bodies stacked with a separation layer therebetween, are sintered. Boron nitride paste contains 0.01 to 0.50% by oxygen mass and 0.001 to 0.5% by carbon mass, and c/a is within range of 0.02 to 10.00, where c is oxygen content in the powder of the boron nitride paste, and a carbon content in the degreased separation layer, which includes 0.2 to 3.5 mg/cmof hexagonal boron nitride powder.