Study On The Electrical Performance Of High Energy Density Ceramic Capacitor

Pulsed power technology has been widely used in the fields of national defense, biomedicine, scientific experiments and environmental protection etc. As one of the key components, high energy density components with slow aging, steady electrical performance as well as long lifetime is greatly expected to meet the fast development of the pulsed power technology. This thesis is devoted to the object on ceramic capacitors and their electrical performance such as ceramic dielectric, lifetime and reliability. First of all, the pulsed power technology and energy storage components are represented in chapter 1. Mean while, the development status of multi-layer ceramic capacitor(MLC)home and aboard and the main research contents are described as well. Secondly, some deep research on the factors affecting the energy storage density of the ceramic capacitors such as the dielectric constant, the electrical breakdown strength and the dielectric loss of ceramic dielectric material are carried out . Furthermore, the characteristics of barium titanate based ceramic dielectric such as the general structure, ferroelectricity, characteristic curve of dielectric constant vs temperature, breakdown strength, frequency, aging and non-linearity are analyzed. Therefore, The interior organization of ceramic dielectric material is introduced, and its influences on electrical performance of ceramic dielectric are also analyzed. Based on the choice of ceramic material and the study on production technique of MLC, the experiments about the electrical performance and reliability have been done by using the samples of high energy density MLC. The experiments mainly contained both destructive experimentation and supersonic wave aided nondestructive test experiment. In order to do the destructive experiment consisting of DC voltage withstanding and repeated charge-discharge tests, the author developed a set of experimental facility by which a large number of experiments on the samples had been done under rated voltage condition and over rated voltage condition. As one result of the experiments, the basic electrical performance of ceramic capacitors as well as therelationship between the operating voltage and the lifetime were obtained. A quick method to assess the reliability of ceramic capacitors were also got through the combination of supersonic wave aided nondestructive test and destructive test. Finally, the whole researches are summarized, and the following work is prospected.