Abstract
Degradation of insulation resistance (IR) of Ni-electrode multilayer ceramic capacitors has been studied with special reference to the microstructure. Oxidation of dielectrics during annealing, after firing at low oxygen partial pressures, is effective to elongate the accelerated life of IR. Segregation layers along the surfaces of Ni electrode, rich in Fe and Mn oxides, are formed during the annealing process. It is supposed that deterioration of grain boundaries is responsible for the degradation of IR.
