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:
Jan. 13, 2015
Filed:
Jun. 12, 2013
Fuji Electric Co., Ltd., Kawasaki, JP;
Osamu Sasaki, Azumino, JP;
Fuji Electric Co., Ltd., , JP;
Abstract
A semiconductor device is disclosed with a protection device formed of a parasitic bipolar transistor, a parasitic diode and a parasitic resistance and operated at a lowered operating voltage to be capable of improving a blocking capability against an over voltage. The impurity concentration in a semiconductor layer as the base of a parasitic bipolar transistor is lower compared with the impurity concentration of a semiconductor layer of the same conduction type arranged adjacently to the semiconductor layer as the base and to be the anode of a parasitic diode. The lowered impurity concentration is determined to be the concentration for making the parasitic bipolar transistor have a snapback phenomenon occur.