Views: 2 Author: Site Editor Publish Time: 2018-03-24 Origin: Site
To a large extent, the breakdown of capacitors depends on its macroscopic structure and technological conditions, and the resulting non-uniform electric field and non-uniform dielectric. The breakdown of capacitors often occurs at these weaknesses. The following are listed below for analysis of the main impact factors.
Effect of dielectric on breakdown of capacitors:
I. when a capacitor is designed, the breakdown voltage of the dielectric is close to the operating voltage, which may cause the capacitor to fail at an early stage at high temperature and high pressure.
II. Under the action of uniform electric field, the microcosmic nature of the medium and the poor quality of the medium, such as the roughness of the surface of the medium, porosity, wrinkle, crack and so on, will reduce the ability of the medium to withstand the electric field and break down the medium.
The mechanism is that the free electrons in the dielectric of capacitors collide with neutral molecules under the action of strong electric field to ionization them to produce positive ions and new free electrons. The rapid development of the ionization process forms an avalanche electron stream, which leads to the breakdown of the medium. Reduce the capacity of its capacitors at high temperature and high pressure.