Experimental Research On The Electric Characteristics Of IGBT Module

IGBT module,as a new generation of power semiconductor devices,is developing in the direction of high frequency,high power and high integration,so the related problems such as electricity and heat is more and more prominent.The dynamic and static electrical parameters of IGBT module are closely related with the temperature of the module,and operation module’s power stress and temperature are affected by each other.As the core part of power electronic equipment,bearing intermittent power stress’ IGBT module can makes its temperature changing repeatedly,so the chip and package will degenerate.Suffering from the changing temperature,the relationship between electrical parameters and temperature will degenerate.Because of the limit of rated working current,the safe working area will reduce.So the research of IGBT module’s electrothermal characteristics has important significance to improve the device performance and reliability.In this paper,we will study the causes of production and influencing factors of IGBT module’ electrothermal characteristics.Through the establishment of power loss calculation module,the paper will analyze the generation mechanism of the electrothermal of IGBT module.The paper will analyze the influence of the IGBT module junction temperature on the physical parameters of the semiconductor,such as carrier concentration,the minority lifetime,the carrier mobility and the diffusion coefficient.And then paper will analyze the influence of the junction temperature on the electrical parameters such as the gate threshold voltage,collector leakage current and saturation voltage drop.The paper will analyze the influence of IGBT module’ electric characteristics of load,environment and cooling system.In this paper,we will study the test and experimental method of general electric heating characteristics in the thermal steady state of IGBT module.The paper will design the junction temperature measurement system based on the fiber optic temperature sensor and design the shell temperature measurement system based on digital temperature sensor.This paper will design the test scheme of the temperature characteristics of the saturated pressure drop under the constant current and the single pulse of high current.Then,the paper study the test method of steady-state thermal resistance based on thermal sensitive parameter method and direct test method.This paper will study the variation of temperaturecoefficient of saturated voltage drop with the load current through experiment,and then,study the test of thermal resistance’ advantages and disadvantages for thermal sensitive parameter and direct test method.In this paper,we will study the test and experimental method for transient electrothermal of IGBT module during thermal transients.We will design and build the experimental circuit which the switch frequency,occupies and load current can be adjusted.The devices can collect the transient waveform of electrical parameters in switch mode of operation and different junction temperature.And then we will analyze the temperature characteristics of the transient electrical parameters.According to the measured results of the junction and shell temperature in switch mode and constant power,we will build the mode of junction and shell temperature.The last,we will design the junction test experiment which IGBT module operates different load current and switching frequency and study the effect of load current and switching frequency on the junction temperature of the module.