为研究压电效应对多层陶瓷电容器放电性能的影响, 搭建了放电周期可调的电路平台和基于光学多普勒效应的高精度振动测量平台。研究了陶瓷介质压电特性, 电容在不同放电周期、不同加载电压下的振动状态和放电特性, 以及失效放电周期和厚度的关系。结果表明,陶瓷介质具有压电效应, 放电时, 介质按交流电场频率规律振动, 当振动频率与电容固有谐振频率一致时, 激发机械共振, 且振动幅度随电压增大而增大, 当振动产生的应变超过介质承受极限时, 介质开裂, 导致击穿失效。失效放电周期随电容厚度增大而增大, 呈线性关系。

In order to study the influence of piezoelectric effect on the discharge performance of multi-layer ceramic capacitors, a circuit platform with adjustable discharge cycle and a high-precision vibration measurement platform based on optical Doppler-effect were set up in this work. The piezoelectric characteristics of ceramic dielectric, the vibration state and discharge characteristics of capacitor under different discharge cycles and loading voltages, and the relationship between the failure discharge cycle and the thickness of capacitor were studied. The results show that the ceramic dielectric has piezoelectric effect. During discharging, the dielectric vibrates according to the frequency rule of AC electric field. When the vibration frequency is consistent with the natural resonance frequency of capacitor, the mechanical resonance is excited, and the vibration amplitude increases with the increase of voltage. When the generated strain generated by vibration exceeds the withstand limit of the dielectric, the dielectric cracks, leading to breakdown failure. The failure discharge cycle increases linearly with the increase of capacitor thickness.