氧化锌压敏电阻老化分析

摘要：限压型电涌保护器（SPD）的老化问题，经分析是由于ZnO压敏电阻内部的离子迁移导致肖特基势垒的畸变，从而引起泄漏电流与压敏电压增加等。通过对几组ZnO压敏电阻在老化环境下的试验，分析老化前后压敏电阻性能参数的变化，得到如下结论：交流老化过程中，压敏电压和漏流存在一定的逆老化现象．但压敏电压和漏流随老化呈增长趋势；（爹交流老化时，压敏电阻温度的升高与加热时间、施加电流以及老化程度有关，伏安特性曲线发生对称漂移；（萤交流老化之后，压敏电阻内阻的变化不大．且局部有降低的趋势，分布电容、阻抗和非线性系数的变化较小。

Analysis on Aging of ZnO Varistor

The aging of voltage limiting type SPD resulted from the distortion of Schottky barrier due to the ionic migration inside of ZnO varistor after analysis, thereby leading to increases of leakage current and varistor voltage. The change of varistor performance parameters before and after the aging is analyzed through the test of several wroups of ZnO varistors under the aging environment. Following conclusions are made： （1） Although reverse aging exists in varistor voltage and leakage current during the AC aging, the varistor voltage and leakage current tend to increase with the aging; （2） The elevated temperature of varistor is related with heating time, applied current and degree of aging during the AC aging. Symmetric drift occurs to volt-ampere characteristic curve; （3） The internal resistance of varistor shows insignificant change and ieduces locally after AC aging. The distributed capacitance, impedance and nonlinear coefficient change slightly.