Research On Blocking Capability Reliability Of Power Devices Under Temperature And Humidity Environment

Power semiconductor devices are widely used in outdoor conditions such as photovoltaic power generation,new energy vehicles,and offshore wind power generation,and their long-term operational reliability is affected by stresses such as temperature,humidity,and electric fields.The High Humidity High Temperature Reverse Bias Test(H3TRB)accelerates the aging of the device through the high temperature and high humidity environment,thereby assessing the reliability of the device;the High-Voltage High Humidity High Temperature Reverse Bias Test(HV-H3TRB)has been proposed in recent years,based on H3TRB,The higher blocking voltage is applied to make the test for devices more severe.Humidity reliability related research have gradually gained attention in recent years.However,its failure mechanism,failure point,macroscopic manifestation are still unclear.thus the relevant test progress needs to be sorted out.First,the relevant test standard conditions and failure criteria are summarized.On this basis.the mechanism of water vapor diffusion and action is discussed in accordance with the physical process of humidity invasion.Furthermore,combined with the state of the art,the test object,test method,failure mode,electrical quantity change,etc.are analyzed and the direction of anti-humidity optimization design is pointed out.Furthermore,the HV-H3TRB aging test was carried out,combined with the dynamic and static.parameter test equipment,and the blocking leakage current.threshold voltage.gate leakage current,junction capacitance change phenomenon caused by aging were analyzed with the help of basic semiconductor principles.The HV-H3TRB aging devices with different packages and chip materials were compared.Then,according to the basic humidity simulation principle,a finite element simulation was established,and the principle difference between the partial pressure method and the wetness fraction method and the equivalent method of the two were compared,and the equivalence was verified through simulation.In addition.according to the HV-H3TRB aging test results,devices with different packaging materials were compared,and it was found that silicone-encapsulated devices were more susceptible to humidity.Finally,the unidirectional coupling of temperature and humidity is considered.and the influence of environmental temperature fluctuations on the relative humidity in the device is simulated,and the chip operation can effectively suppress this fluctuation.