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:
Mar. 26, 1991
Filed:
Apr. 14, 1988
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ;
U.S. Cl.
CPC ...
357 38 ; 357 30 ;
Abstract
A thyristor of the overvoltage self-protection type capable of performing a turn-on operation certainly without being damaged even when an overvoltage is applied across the thyristor is disclosed in which a P-base layer is provided with a recess having such a depth as to generate an avalanche in the vicinity of the bottom of the recess when the overvoltage is applied across the thyristor, and a portion of a P.sup.+ -layer formed on the surface of the recess is kept in contact with an N-emitter layer.