Thermally Stimulated Current Equipment Improvement And Properties Of Al₂O₃/PI Composite Films

The composite inorganic nanoparticles Hybrid Polyimide has excellent mechanical, electrical and thermal properties, widely used in aerospace, mechanical,electrical and microelectronic applications. Polyimide doping and structural defects will be introducing charge traps, formation of trapped electron space charge change electric field distribution in dielectric materials, make it become a major factor in the effect of the dielectric material aging and breakdown characteristics of. Thermally stimulated current of polymer structure, space charge storage and transport tools, can effectively characterize the shallow trap level distribution.In this paper, we first introduce the working principle of thermally stimulated current test equipment, for existing thermally stimulated current equipment temperature control is not accurate, and by the temperature in response to the impact of speed on the thermally stimulated current measurement and other issues are briefly analyzed. Then by using copper foil(0.07mm) instead of the original thickness copper electrodes for 35 mm, reduce the heat capacity of the electrode system, with round, no inductive heating plate to replace the original heating rods,enhance the uniformity of surface temperature of electrode, influence and reduce the heat generated when the induced current of the test. The improved heat shock test equipment has the characteristics of fast temperature response, good linearity, high accuracy of current signal and so on.In order to adapt to the thermally stimulated current the need to film thickness measuring method, the study of preparation process of polyimide composite films with a thickness of up to 400 μ m, on this basis, the preparation of gas phase and gas phase Al2O3 nanoparticle doped composite films, nano particle size respectively 20 nm and 30 nm, the group of 5%, 10% and 15% respectively. To observe the morphology of thin films using scanning electron microscopy, the results show that the thin film uniformity, the tensile strength increased from 150 mPa to 172 mPa.The thermally stimulated current on the preparation of Al2O3 composite films isanalyzed in this paper. In the same group, the gas phase Al2O3 hybrid composite films thermally stimulated current peak higher than non gaseous particles of about20 pA, gas phase Al2O3 nano particles doping introduced more shallow trap charge,charge trap density increase. Gas phase Al2O3 nano particles doping the breakdown strength of the pure polyimide film increased by 170 kV to 241 kV, gas phase Al2O3 doped than gas phase Al2O3 doped polyimide film the corona aging time increased by19 h; the peak separation method calculated doping amount of 15wt% than the composite film doped 5wt% in trap density of high temperature alpha peaks higher than doubled; gas phase Al2O3 nano particle size is small, composite films in charge traps more.