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:
Jul. 21, 1987
Filed:
Apr. 28, 1983
Tsutomu Yatsuo, Hitachi, JP;
Naohiro Momma, Hitachi, JP;
Masayoshi Naito, Hitachi, JP;
Masahiro Okamura, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a high-voltage thyristor comprising a semiconductor body having contiguous pnpn four layers, and opposed anode and cathode electrodes and a gate electrode provided for the semiconductor body, one of p-base and n-base regions having an impurity concentration higher than the other has an impurity concentration which is no more than 8.times.10.sup.15 atoms/cm.sup.3 in the vicinity of a junction between the one base region and an adjacent emitter region and which has a gradually decreasing gradient toward the other contiguous base region. The one base region has a sheet resistance of 500 to 1500 ohms/.quadrature.. The realization of a high-voltage, large-diameter and large-current thyristor can be ensured.