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. 19, 1982
Filed:
Jun. 27, 1980
John Bartko, Monroeville, PA (US);
Krishan S Tarneja, Pittsburgh, PA (US);
Chang K Chu, Pittsburgh, PA (US);
Earl S Schlegel, Plum Borough, PA (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
A method of reducing the reverse recovery charge of thyristors without substantially increasing forward voltage drop by first determining the depth of the anode PN junction from a major surface adjoining a cathode emitter region. The depth of maximum defect generation in thyristor on irradiation through the major surface with a given radiation source radiating particles with molecular weight greater than one, preferably proton or alpha particles, and adjusting the energy level at the major surface of the thyristor from the radiation source to provide the depth of maximum defect generation adjacent the anode PN junction and preferably in the anode base region within 20 micrometers of the anode PN junction or in the anode emitter region within 15 micrometers of the anode PN junction. Thereafter the thyristor is irradiated through said major surface with the adjusted energy level from the radiation source to a given dosage to reduce the reverse recovery stored charge of the thyristor without substantially increasing the forward voltage drop.