Power MOSFET health state assessment and residual life prediction method

Abstract

The invention discloses a power MOSFET health state assessment and residual life prediction method. The concrete steps are that: drain and source electrode voltage, drain and source electrode current and threshold voltage of a health power MOSFET are firstly acquired, mahalanobis distance of the health power MOSFET is acquired and Box-Cox conversion is performed so that the mahalanobis distance in normal distribution is acquired, then a health state assessment reference threshold of the power MOSFET is confirmed, and the mahalanobis distance in normal distribution is selected as a health state characteristic parameter for assessing the measured power MOSFET; then the health state assessment is performed on the drain and source electrode voltage, the drain and source electrode current and the threshold voltage monitoring the measured power MOSFET; and finally different residual life prediction models are established according to different health states of the measured MOSFET. Multi-characteristic parameters of the power MOSFET are converted into a single-characteristic parameter to perform the health state assessment. Meanwhile, temperature and voltage stress of working conditions are considered, and the residual life prediction models under the normal states and the abnormal states are established so that the residual life of the measured power MOSFET can be accurately predicted.

Description

technical field [0001] The invention relates to a power MOSFET health state evaluation and remaining life prediction method, which belongs to the fields of reliability evaluation, electronic failure prediction and health management. Background technique [0002] With the continuous progress and development of semiconductor technology, power MOSFET, as the main choice of switching power devices in power electronic circuits such as DC-DC power modules and photovoltaic inverters, is an indispensable device in electronic and electrical airborne autonomous functional subsystems , Widely used in aerospace, rail transit, new energy power generation, navigation and radar systems and other fields. Usually, the degradation or failure of the circuit is often caused by one or some key components. According to research statistics, the failure rate caused by power MOSFETs in power electronic circuits is as high as 31%. For mission-critical systems, their performance degradation and failu...

AI Technical Summary

Problems solved by technology

[0003] At present, there are many domestic and foreign studies on the failure mechanism and failure mode analysis of power MOSFETs, but there are few studies on health status assessment and remaining life prediction. The method used is to select a single on-resistance or threshold voltage as the failure mode. Health assessment or failure prediction based on characteristic parameters, that is, only considering the degradation law in the case of a certain failure mode

However, in the actual working process, the power MOSFET is subjected to simultaneous stresses such as temperature and voltage, and its failure form may be characterized by multiple failure modes

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