AGING BEHAVIOR OF NI-ELECTRODE MULTILAYER CERAMIC CAPACITORS WITH X7RCHARACTERISTICS

Capacitance aging under de field has been studied on BaTiO3-based diel ectrics with X7R characteristics for multilayer ceramic capacitors wit h Ni internal electrodes. Capacitance change strongly depends on addit ives and firing conditions as well as microstructure. Aging behavior u nder no dc field is well explained by Richter's relaxation curve. On t he other hand, aging under de field cannot be fitted by Richter's curv e. Therefore, a new model which assumes two factors that affect relaxa tion is proposed. According to the new model, capacitance changes in t wo stages, short-term and long-term relaxations. Capacitance change in short-term relaxation strongly depends on applied de field. On the co ntrary, that of long-term relaxation does not depend on de field.