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. 25, 2001
Filed:
Dec. 21, 1998
Toshihiro Iwaida, Kokubu, JP;
Teruhisa Makino, Kokubu, JP;
Masanobu Ishida, Kokubu, JP;
Tomohide Hasegawa, Kokubu, JP;
Hirosi Okayama, Kokubu, JP;
Kyocera Corporation, Kyoto, JP;
Abstract
A wiring board of the present invention is equipped with an insulating board formed of a sintered product of silicon nitride containing a silicon nitride crystal phase, and a metal circuit formed on said insulating board, wherein said sintered product of silicon nitride contains a rare earth element (RE) and magnesium in a total amount of from 4 to 30 mol % calculated as oxides and at a molar ratio (RE,O,/MgO) calculated as oxides of from 0.1 to 15, and has a relative density of not smaller than 90% and a heat conductivity of not smaller than 50 W/m·K. The wiring board is equipped with the insulating board having very excellent heat-radiating property and a large strength, and is very useful as a wiring board for, for example, power modules.