氧化锌压敏电阻的老化机理

Degradation Mechanism of ZnO Varistors

研究了ZnO压敏电阻的老化现象,提出了一种新的老化机理-线性链理论。该理论认为,在外电场作用下,压敏电阻势垒高度降低;当降低到一定值时,晶界可变电阻转化为线性晶界电阻,从而压敏链转化为线性链。线性链是稳定的,因而压敏电阻老化到一定程度后其电性能将不能完全恢复。

This paper deals with the degradation of ZnO varistors. A new degradation mechanism which is called as LC (Linear Chain) mechanism has been put forward. LC mechanism suggests that at the begining of the degradationion migration which happens in varistor chain (VC) lowers the barrier height and when the barrier height decreases to some extent, VC Changes to LC; then the proliferation of LC leads to a thermal runway. LC which is stable in properties can not be transformed to LC reversibly, so the properties of ZnO varistors after degradation to some extent can not recover to the ones before degradation also.