基于低频噪声检测的电力MOSFET可靠性分析

针对变电所中通信电源的核心器件电力金属氧化物半导体场效应晶体管(power MOSFET,P-MOSFET)在大功率、强电流下易损坏、故障率高,直接影响电力通信业务的安全稳定运行的问题,提出了一种基于低频噪声检测的可靠性分析方法.利用互功率谱测量方法检测P-MOSFET内部的本征低频噪声,根据频段阈值法的拐点噪声谱,确定P-MOSFET筛选的上下限阈值大小,建立了P-MOSFET的1/f噪声功率谱密度及其阈值的对应关系式.实验结果表明,与传统的有损检测法相比,该方法能够有效评估P-MOSFET的三种可靠性等级,提高了可靠性筛选的准确率,为其他晶体管的可靠性评估提供了参考.

Reliability Analysis of the Power MOSFET Based on Low-Frequency Noise Detection

The power metal oxide semiconductor field effect transistor (P-MOSFET) which is the core device of communication power supply in substation is easily damaged with high failure rate under high power and current.It directly affects the safe and stable operation of the power communication business.Aiming at the problem,a reliability analysis method based on low-frequency noise detection was proposed.Cross-power spectrum measurement method was used to detect the intrinsic low frequency noise inside the P-MOSFET.The upper and lower threshold values of the P-MOSFET screening were determined according to the inflection point noise spectrum of the frequency band threshold method.The corresponding relation between the 1/f noise power spectral density of the P-MOSFET and its threshold was established.The experimental results show that compared with the traditional lossy detection method,the proposed method can effectively evaluate the three reliability levels of the P-MOSFET and improve the accuracy of reliability screening,which provides a reference for the reliability evaluation of other transistors.