能量脉冲对ZnO压敏电阻静态老化性能的影响

Influence of Energy Pulse on Degradation Due to a Continuous Stress in High energy ZnO Varistors

研究了能量脉冲对高能ＺｎＯ压敏电阻在可控硅整流电压下的静态老化性能的影响以及可控硅整流电压的过电压对压敏电阻的作用。过电压使压敏电阻流过频率为３００Ｈｚ的脉冲电流，从而使晶界势垒高度下降和晶粒导电性增加；经受能量脉冲后的压敏电阻的静态老化电流增长速度远大于未经能量脉冲的压敏电阻的静态老化电流增长速度，即能量脉冲使静态老化性能严重变差。

The influence of energy pulse on the degradation phenomena due to a continuous SCRV (silicon controlled rectification voltage ) in high energy ZnO varistors and the action of the overvoltage existing in the SCRV on varistors are investigated in this paper.The overvoltage causes a current pulse in the varistors with a frequency of 300 Hz, which leads to the deformation of the grain boundary barrier and to the increase of the grain conductivity. When a SCRV being applied to a varistor,the values of the degradation currents,the peak current and the average current, increase continuously. The rate of above increase in the varistor after being impulsed by the energy pulse is larger than that in the varistor without being impulsed,which indicates that the energy pulse accelerates the degradation in high energy ZnO veristors.