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:
Oct. 30, 2012
Filed:
Jan. 26, 2011
Hiroshi Inagawa, Kanagawa, JP;
Hiroshi Inagawa, Kanagawa, JP;
Renesas Electronics Corporation, Kawasaki-shi, JP;
Abstract
In a reverse conducting IGBT, diode cathode regions are formed dispersedly on the back side of a device chip. When the distribution density of the diode cathode region becomes low, VF of a fly-back diode, that is, a forward voltage drop becomes large. On the other hand, when the distribution density of the diode cathode region becomes high, it becomes hard for a PN junction at a collector part to turn ON and a snap back occurs. In contrast to this, there is a method of providing about one to several diode cathode absent regions having a macro area, however, the arrangement of the regions itself directly affects the device characteristics, and therefore, it is difficult to control the device characteristics and variations thereof. In the present invention, dot-shaped diode cathode regions on the back side of the device chip are distributed into the shape of a substantially uniform XY lattice and at the same time, the lattice constant in a Y direction is made longer than that in an X direction in parallel with a linear gate electrode in a reverse conducting IGBT having a large number of the linear gate electrodes.