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. 29, 2022
Filed:
Dec. 11, 2020
Kabushiki Kaisha Toshiba, Tokyo, JP;
Toshiba Materials Co., Ltd., Yokohama, JP;
Katsuyuki Aoki, Yokohama Kanagawa, JP;
Takayuki Fukasawa, Yokohama Kanagawa, JP;
Jun Momma, Yokohama Kanagawa, JP;
Kentaro Iwai, Yokohama Kanagawa, JP;
KABUSHIKI KAISHA TOSHIBA, Tokyo, JP;
TOSHIBA MATERIALS CO., LTD., Yokohama, JP;
Abstract
In a silicon nitride substrate including a silicon nitride sintered body including silicon nitride crystal grains and a grain boundary phase, a plate thickness of the silicon nitride substrate is 0.4 mm or les, and a percentage of a number of the silicon nitride crystal grains including dislocation defect portions inside the silicon nitride crystal grains in a 50 μm×50 μm observation region of any cross section or surface of the silicon nitride sintered body is not less than 0% and not more than 20%. Etching resistance can be increased when forming the circuit board.