Reasons Analysis on Failure of Multi-layer Ceramic Chip-capacitors

The breakdown failure occurred to multi-layer ceramic chip-capacitors during the electrical property testing process of some products. By the methods of macrographic examination, scanning electron microscope analysis, linear expansion coefficient testing, thermogravimetic analysis and so on, failure reasons of multi-layer ceramic chip-capacitors were analyzed. The results show that the failure reason of multi-layer ceramic chip-capacitors was that the linear expansion coefficient had large difference between the epoxy resin for fixation and the ceramic capacitor body, thus the alternating thermal stress generated by the epoxy resin was extremely large during the temperature impacting, which resulted in the cracking of capacitance ceramics. Finally according to the failure reason, the improvement measure of adding a process of vacuum coating was put forward, which prevented the failure from happening again.