高温可靠性测试如高温栅偏(High Temperature Gate Bias,HTGB)、高温反偏(High Temperature Reverse Bias,HTRB)、高温高湿反偏(High Humidity High Temperature Reverse Bias,H3TRB)是器件出厂和寿命评估必备的测试。然而,不同标准的...高温可靠性测试如高温栅偏(High Temperature Gate Bias,HTGB)、高温反偏(High Temperature Reverse Bias,HTRB)、高温高湿反偏(High Humidity High Temperature Reverse Bias,H3TRB)是器件出厂和寿命评估必备的测试。然而,不同标准的测试条件不尽相同,其对应的内在机理也不明确。为讨论测试条件的确定原则,首先从单个和耦合的温度、电场、湿度加速老化模型出发,论述了相关测试标准所用模型,分析了其应用范围和使用原则。进一步地,总结了现有各类标准下的测试条件,计算了电动汽车模块正常运行30年所需HTGB、HTRB、H3TRB加速老化时间分别为832 h、866 h、1038 h,测试的样本数均为70,并指出测试时间、样本数需根据实际工况决定。最后,基于以上分析,提出了一种加速老化时间、样本数可调的高温可靠性测试流程。展开更多
Ground lifetime test is the most crucial experiment to assess the performance,reliability.and flight qualification of electric propulsion,and it can bring new insights for understanding the operation characteristics.T...Ground lifetime test is the most crucial experiment to assess the performance,reliability.and flight qualification of electric propulsion,and it can bring new insights for understanding the operation characteristics.This work demonstrates a full lifetime test of 140000 cycles on a Micro-Cathode-Arc Thruster(μCAT)with 160μs charging time and 86 mJ charging energy.A four-probe resistivity measurement method is utilized to investigate variations in the conductive film thickness and resistivity throughout the thruster lifespan.Direct film parameters show that the lifetime of theμCAT can be divided into three stages.In the initial stage,the film thickness decreases by 1.2μm and the resistivity increases significantly due to the high discharge intensity and intense film ablation;In the steady stage,the change of the film thickness is within 5%,and the resistivity of the film increases slowly from 0.050Ω·mm to 0.223Ω·mm.In the end stage,the resistivity exponentially increases from 0.223Ω·mm to 1.176Ω·mm,with the increase accounting for 81%,ultimately resulting in the failure of the thruster open circuit.Additionally,the evolution of discharge parameters,and the variation of plume parameters are measured throughout the life-time.The discharge characteristics also show significant differences in the duration of voltage and current in these three stages.The results of plume shape and plasma parameters are also well con-sistent with the discharge parameters and film state.These results suggest that,for evaluating the steady stage lifetime of thrusters,the film thickness is the best indicator compared to the variations in resistivity and voltage-current characteristics.For the end stage,the plasma plume morphology.discharge duration,and plume parameters can conveniently and clearly characterize the thruster failures and irregularity.展开更多
文摘高温可靠性测试如高温栅偏(High Temperature Gate Bias,HTGB)、高温反偏(High Temperature Reverse Bias,HTRB)、高温高湿反偏(High Humidity High Temperature Reverse Bias,H3TRB)是器件出厂和寿命评估必备的测试。然而,不同标准的测试条件不尽相同,其对应的内在机理也不明确。为讨论测试条件的确定原则,首先从单个和耦合的温度、电场、湿度加速老化模型出发,论述了相关测试标准所用模型,分析了其应用范围和使用原则。进一步地,总结了现有各类标准下的测试条件,计算了电动汽车模块正常运行30年所需HTGB、HTRB、H3TRB加速老化时间分别为832 h、866 h、1038 h,测试的样本数均为70,并指出测试时间、样本数需根据实际工况决定。最后,基于以上分析,提出了一种加速老化时间、样本数可调的高温可靠性测试流程。
基金supported by the National Natural Science Foundation of China(No.52177128).
文摘Ground lifetime test is the most crucial experiment to assess the performance,reliability.and flight qualification of electric propulsion,and it can bring new insights for understanding the operation characteristics.This work demonstrates a full lifetime test of 140000 cycles on a Micro-Cathode-Arc Thruster(μCAT)with 160μs charging time and 86 mJ charging energy.A four-probe resistivity measurement method is utilized to investigate variations in the conductive film thickness and resistivity throughout the thruster lifespan.Direct film parameters show that the lifetime of theμCAT can be divided into three stages.In the initial stage,the film thickness decreases by 1.2μm and the resistivity increases significantly due to the high discharge intensity and intense film ablation;In the steady stage,the change of the film thickness is within 5%,and the resistivity of the film increases slowly from 0.050Ω·mm to 0.223Ω·mm.In the end stage,the resistivity exponentially increases from 0.223Ω·mm to 1.176Ω·mm,with the increase accounting for 81%,ultimately resulting in the failure of the thruster open circuit.Additionally,the evolution of discharge parameters,and the variation of plume parameters are measured throughout the life-time.The discharge characteristics also show significant differences in the duration of voltage and current in these three stages.The results of plume shape and plasma parameters are also well con-sistent with the discharge parameters and film state.These results suggest that,for evaluating the steady stage lifetime of thrusters,the film thickness is the best indicator compared to the variations in resistivity and voltage-current characteristics.For the end stage,the plasma plume morphology.discharge duration,and plume parameters can conveniently and clearly characterize the thruster failures and irregularity.
