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. 27, 2003
Filed:
Sep. 21, 2001
Takayuki Naba, Ibo-Gun, JP;
Haruhiko Yamaguchi, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
The present invention provides a ceramic circuit board comprising: a ceramic substrate and a metal circuit portion bonded to at least one main surface of the ceramic substrate; wherein each of ratios of Ra /Ra and Ra /Ra is 1.5 or less in which a surface roughness in terms of arithmetical average surface roughness Ra in arbitral one direction of the ceramic substrate is Ra while a surface roughness Ra in a direction normal to the one direction of the ceramic substrate is Ra , and a breakdown voltage of the ceramic substrate is 20 kV/mm or more. According to the above structure of the present invention, there can be provided a ceramic circuit board having an excellent heat-cycle resistance and bending strength characteristics without impairing a heat radiating property, and capable of increasing an operating reliability as electronic device.