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. 10, 2017
Filed:
Feb. 17, 2012
Shigeki Sato, Matsumoto, JP;
Shigeki Sato, Matsumoto, JP;
FUJI ELECTRIC CO., LTD., Kawasaki-shi, JP;
Abstract
A wafer test method of a power switch wherein a main IGBT and a current detecting IGBT that detects a current value of the main IGBT are integrally formed on the same semiconductor substrate is such that there is provided resistance means that causes an emitter current of the current detecting IGBT to flow through an emitter terminal of the main IGBT, the main IGBT and current detecting IGBT are energized simultaneously, thereby applying a constant current to a common collector terminal of the main IGBT and current detecting IGBT, and a current ratio (main current/detected current) between a main current of the main IGBT and a detected current of the current detecting IGBT is calculated from the current flowing through the current detecting IGBT, obtained from the voltage across the resistance means, and the constant current.