包封材料的改进及其对压敏电阻大电流耐受性能的影响

Study on epoxy resin for improving the impulse stability of ZnO varistors

为了满足 IEC和国标对避雷器阀片大电流冲击耐受性能指标的要求 ,通过对环氧树脂配方及工艺的调整 ,研制了新型环氧包封材料 ,使环氧树脂与氧化锌瓷体的热膨胀系数更加匹配 。

We have developed a method to improve the impulse stability of ZnO varistors by adjusting the composition and process of epoxy resin.Common coat materials do not have adequate reliability against thermal shock caused by impulse.The thermal stability of epoxy resin was determined and correlated with their compositions.In this paper,it is proved that fitting additions can improve impulse stability of epoxy resin.The coefficient of expansion of epoxy resin has been adjusted to more matching to that of ZnO element by adding filling.The reliability against thermal shock of ZnO varistors has been improved greatly.