Research On Pulse Power Accelerated Aging Experiment And Health Status Classification Evaluation Of IGBT Power Module

With the development of new energy technology,power devices,as the core components of power converter,have rapidly expanded their application scope and increased their demand in energy,metallurgy,transportation,new materials and other industries.Insulated gate bipolar transistor(IGBT)is the core device of power converter because of its simple driving circuit and high voltage and current level.Due to the fatigue aging of IGBT module during use,when the aging accumulates to a certain extent,the device will age and fail,resulting in system instability.Therefore,in order to improve the system stability,it is necessary to study the failure mechanism of power devices,evaluate the current health level of devices,and give early warning of failure in time.Health status assessment is an effective means to actively improve the reliability of power semiconductor devices.At present,there are still some problems in the research on health status assessment of IGBT power module,such as insufficient failure data,failure judgment and state judgment.Therefore,taking the commonly used bonding wire welded IGBT power module as the research object,this paper studies the characterization relationship between its failure mode and aging characteristic quantity,pulse power accelerated aging experimental method and health state classification evaluation method,in order to provide some feasible methods and theoretical support for the reliability research of IGBT power module.The main work of this paper is as follows:By studying the physical and chemical properties of failed IGBT modules,this paper summarizes the basic failure mechanism,analyzes and screens the aging characteristic quantity of IGBT modules.Firstly,based on the packaging structure of IGBT module,the aging failure mechanism and two aging failure modes of the module are analyzed;Then the corresponding aging characteristic quantities are selected according to the two failure modes,and the relationship between the characteristic quantities and module aging failure is analyzed.The aging failure of bonding line can be mainly characterized by saturated voltage drop and short-circuit current,and the failure of solder layer can be mainly characterized by steady-state thermal resistance.In this paper,the pulse power accelerated aging experimental platform of IGBT module is built,the change of aging characteristic quantity is monitored in the aging process,and the aging data are analyzed combined with the device failure phenomenon.In this paper,the aging main circuit and driving circuit based on H-bridge inverter topology are designed,and the aging control strategy is formulated.At the same time,according to the two aging characteristics of saturation voltage drop and thermal resistance,the corresponding measuring circuit is designed,the experimental platform is reasonably constructed,and the accelerated aging experiment of IGBT module is carried out through the experimental platform,During the experiment,the aging characteristic quantity is measured automatically and in real time,and the measured data are collected and stored at the same time;The results of aging test show that the saturation pressure drop increases slowly in the middle of aging and jumps in the later stage;The maximum thermal resistance of crusts increased by 15%.This paper presents a health status classification and evaluation model of IGBT module based on clustering classification algorithm.Two aging characteristic quantities are selected as sample input,and the clustering center of each interval is obtained after calculation by K-means algorithm.Then,according to the distance from the sample point to the health state center,the health state of IGBT module can be roughly divided into three health state intervals: Health period,fault early warning period and failure period.In this paper,the health evaluation of the tested IGBT module is carried out by using the classified evaluation method in two ways: line cutting simulation aging and pulse power accelerated aging.According to the data collected in the experiment,the evaluation results are consistent with the actual results,which verifies the correctness of the proposed IGBT module health status classification evaluation model.