TSC测试中寄生电流的特性研究

热刺激电流测试(TSC)中寄生电流的存在对测试结果会产生一定的影响.通过对TSC电极系统的热电效应测试和聚酰亚胺的寄生电流、TSC测试,分析了寄生电流产生的机理及特性,探讨了寄生电流对TSC测试的影响.研究表明寄生电流主要由聚酰亚胺中的恒偶极子松弛产生,热电效应和聚酰亚胺内部陷阱电荷释放并非主导因素.当聚酰亚胺内部结构发生变化时,寄生电流将改变.寄生电流叠加于TSC电流中,严重影响了TSC测试精度,为消除其影响可扣除TSC电流中的寄生电流.

A Study of Parasitic Galvanic Current Existing in Thermally Stimulated Current Measurement

Thermally stimulated current (TSC) is used to obtain the parameters of dielectrics,but the parasitic galvanic current existing in test influences the consequence. In this paper,the tests of thermoelectric effect of electrodes,parasitic galvanic current and TSC have been done. The mechanisms of TSC and parasitic galvanic current are discussed. It is shown that the parasitic galvanic current is caused mostly by the relaxation of permanent polarized dipoles. The proportion of thermoelectric effect and trapped charges release to the parasitic galvanic current is small. The microscopic structural changes of dielectrics would make the parasitic galvanic current alter. The parasitic galvanic current changes with the temperature rising,and the precision of TSC measurement is affected seriously. To eliminate the interference mentioned above,a correction approach for TSC test is presented.