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:
Feb. 01, 2011
Filed:
Feb. 17, 2006
Katsuyuki Torii, Niiza, JP;
Masaki Kanazawa, Niiza, JP;
Katsuyuki Torii, Niiza, JP;
Masaki Kanazawa, Niiza, JP;
Sanken Electric Co., Ltd., , JP;
Abstract
A semiconductor deviceincludes a first transistorplaced on a substrate, a second transistorplaced on the first transistorvia a heat radiation layer, a third transistorplaced on the substrate, and a fourth transistorplaced on the third transistorvia a heat radiation layer. The first transistorhas a first region corresponding to a region where the second transistor is placed, and a second region which is formed so as to surround the first region and in which the rate of area occupied by the emitter region in the base region is higher than in the first region. Likewise the first transistor, the third transistorhas a region in which the rate of area occupied by the emitter region in the base region is varied.