Soaking trench gate IGBT structure

Abstract

The invention provides a soaking trench gate IGBT (Insulated Gate Bipolar Translator) structure. The soaking trench gate IGBT structure comprises an effective IGBT cell and a gate thermosensitive control unit, the effective IGBT cells are arranged to be trench gate type IGBT cells; the grid thermosensitive control unit comprises two thermistors and two diodes; wherein one thermistor and one diode are connected in series to form a first series branch for controlling the opening speed of the gate, one end of the first series branch is connected with the trench gate, and the other end is connected with the gate metal; wherein the other thermistor and the other diode are reversely connected in series to form a second series branch for controlling the gate turn-off speed, one end of the second series branch is connected with the trench gate, and the other end of the second series branch is connected with the gate metal. According to the invention, through the trench gate and the thermosensitive gate resistor which are independently arranged, the switching speed of a single cell is automatically adjusted according to the temperature of the cell, so that the loss of the cell with high temperature is reduced, and the purpose of reducing the junction temperature of the cell is achieved. And for the whole IGBT chip, heat balance is realized.

Description

technical field [0001] The invention belongs to the field of semiconductor power devices, in particular to a heat-spreading trench gate IGBT structure. Background technique [0002] The IGBT structure is invented by introducing the P+ region on the back substrate of the power MOSFET, so it can be regarded as a new type of power device that combines the power MOSFET and BJT, and has both the driving power of the MOS structure and the switching speed. , and the advantages of reduced saturation voltage drop and strong load capacity of BJT devices, gradually replace MOSFETs and BJT devices in converter systems with a DC voltage of 600V and above. Therefore, IGBT is widely used in various fields such as motor control, induction cooker, air filter frequency conversion, locomotive traction, high-voltage direct current transmission, etc., and has become the most popular power device. [0003] The current mainstream IGBT structure is trench gate field stop type IGBT, which has bette...

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Problems solved by technology

[0005] 1. The gate resistance controls the switching speed of the entire chip cell; therefore, the cell farther away from the gate metal may have switching lag, which will easily cause the first conducting cell to bear most of the current, causing the IGBT switching process The phenomenon of current concentration; current concentration can easily lead to heat concentration, which can cause device failure under high-voltage current conditions; especially for chips with large areas, in-plane consistency is particularly important

[0006] 2. The thermal distribution in the chip surface is very important to reliability. Generally speaking, the center temperature is high and the edge temperature is low; for long-term use in areas with high temperature, the failure rate is higher than that in areas with low temperature; there is no very effective design yet The method realizes the temperature adjustment of a single cell and optimizes the in-plane temperature consistency

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