Effects of Interfaces of Different Ceramic Phases on Dielectric Properties of MLCCs

By means of scanning electron microscope and the impedance analyzer, the effects of interfaces among different ceramic phases on dielatric properties of composite MLCCs were investigated. The experimental results indicate that evident diffusion layers exist at the interfaces of different phases. On one hand, the formation of interfaces between dielectric ceramics with different Curie temperatures seem helpful to improve the permittivity-temperature characteristic of MLCCs and the adhesion intensity of interfaces, but it will destroy the original design of structure and then change the capacitance of parts. One the other hand, the cofiring defects, such as cracks, holes and so on, tend to appear because of the sintering mismatch between different ceramics, which will raise the dielectric loss. Relatively loosen niterfaces easily cause the paste leakage when electroplating the end electrode, degrading the reliability of MLCCs.