Microstructures and Highly Accelerated Lifetime Test of X5R Type BaTiO sub(3)-Based Ni-MLCC with Ultra-Thin Active Layers

Microstructure control in thin-layer multilayer ceramic capacitors (MLCCs) is one of the challenges for increasing capacitive volumetric efficiency and high voltage dielectric properties. In this paper, the X5R-MLCCs with ultra-thin dielectric layers (~1.2 mu m) owning uniform grain size distribution were prepared by wet casting process. The microstructures and dielectric properties of the MLCCs were investigated. The existence of core-shell structure was proved by transmission electron microscopy observation and energy dispersive spectroscopy analysis. The existence of core-shell structure makes the temperature coefficient of capacitance (TCC) performance meet X5R standard. Moreover, a highly accelerated lifetime test (HALT) result shows that MLCCs with ultra-thin layers under high electric field are more easily to fail with increasing test temperatures. And the results reveal that the activation energy is similar to the value reported for mid-dielectric constant dielectrics.