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:
Apr. 04, 1995
Filed:
Dec. 17, 1993
Applicant:
Inventor:
Masahide Miyagi, Kanagawa, JP;
Assignee:
Fuji Electric Co., Ltd., Kanagawa, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B32B / ;
U.S. Cl.
CPC ...
428209 ; 428210 ; 428901 ;
Abstract
An insulating substrate for mounting semiconductor devices that is composed of a thin flat plate of inexpensive alumina (Al.sub.2 O.sub.3) preferably in the range of 0.26 to 0.29 mm in thickness. Copper foil sheets are applied to both sides of the flat plate with edges spaced a distance back from the end surface of the plate to increase air path distance between the edges of the sheets of foil applied to opposite sides of the plate. The difference in distance between the end surface of the alumina plate and the edges of each copper foil is 0.5 mm or less to balance thermal stress upon heating and cooling of semiconductors soldered to the copper foil.