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, 1990
Filed:
Apr. 25, 1989
Applicant:
Inventors:
Tadashi Tanaka, Chiba, JP;
Kazuo Matsumura, Kanagawa, JP;
Hiroshi Komorita, Kanagawa, JP;
Nobuyuki Mizunoya, Kanagawa, JP;
Assignee:
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Primary Examiner:
Int. Cl.
CPC ...
H05K / ;
U.S. Cl.
CPC ...
174260 ; 174257 ; 174258 ; 174259 ; 428612 ; 428687 ;
Abstract
A bonded ceramic-metal composite substrate comprising a ceramic substrate having opposite surfaces and a copper sheet having a face directly bonded to one of the surfaces of the ceramic substrate, wherein the median surface roughness (R.sub.a) of the outer surface of the copper sheet is not greater than 3 .mu.m, and the maximum surface roughness (R.sub.max) of the outer surface of the copper sheet is not greater than 18 .mu.m. The invention improves the manufacturing reliability of various electronic devices such as semiconductor modules.