低压压敏陶瓷晶界、晶粒电阻的估算方法探讨

A Discussion of the Ways to Estimate the Resistances of the Grain and the Grain Boundary about the Low-voltage Varistor Ceramics

总结出低压压敏陶瓷试样晶粒、晶界电阻的几种估算方法,通过对大量试样的测试分析发现较好的估算方法就是:利用HP4192A测量的数据,绘出复阻抗图,在13MHz附近找10多个点,估计曲线的形状外推左延与横轴相交,将交点所示值看成晶粒电阻;在很低电压(0.01V)下,利用HP4140B皮安计测漏电流,计算所得的绝缘电阻看成晶界电阻.

The author summed up some ways to estimate the resistances of the grain and the grain boundary about the low-voltage varistor ceramics. By testing and analyzing amount of samples, the author found such better ways as these: using the data tested by HP4192A, drawing the image of R-X and looking for more than ten dots around 13MHz , estimating the shape of the line and extending it then making it intersect the X axis, the value of the intersection would be seen as that of the grain resistance; under the low voltage( 0.001V) using HP4140B to measure the drain current and calculating the resistance, the value would be seen as that of the grain boundary resistance .