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:
Aug. 29, 2006
Filed:
May. 05, 2004
Koh Yoshikawa, Nagano, JP;
Katsunori Ueno, Nagano, JP;
Hiroshi Kanemaru, Nagano, JP;
Abstract
An IGBT having a trench gate structure is disclosed which generates decreased noise at switching and displays superiority in saturation voltage to turn-off loss characteristics (trade-off characteristics). In a part of a region on an emitter side surface interposed between trench gates, a sub well region is provided, which is connected to an emitter electrode through diodes. When the IGBT is in a turned-on state, the diodes are brought into a non-conduction state to isolate the sub well region from the emitter electrode, by which carriers are accumulated. When the IGBT is in a turned-off state, the diodes are brought into a conduction state to electrically connect the sub well region to the emitter electrode, by which carriers are discharged at a high speed. In an early stage of turning-on of the IGBT, capacitance of a portion of the gate facing the sub well region is converted to gate-emitter capacitance to thereby reduce gate-collector capacitance, by which electromagnetic noise at switching is reduced.