RELIABILITY OF MULTILAYER CERAMIC CAPACITORS WITH NICKEL ELECTRODES

The reliability of multilayer ceramic capacitors (MLCCs) with Ni inter nal electrodes has been studied from the viewpoint of partial oxygen p ressure (P-O2) during firing. It is shown that the load-life time of t he insulation resistance (IR) was prolonged by firing under low P-O2, annealing after firing, and the addition of dopants. It is also shown that the generation of oxygen vacancies led to the degradation of IR. Annealing treatment for the oxidation of the dielectric body accelerat es the dielectric aging of MLCCs. It is found that the appropriate con trol of the P-O2 during firing can improve the reliability of MLCCs wi th Ni electrodes to a level as high as that of MLCCs with precious met al electrodes. Thus, we have developed an MLCC with Ni electrodes that features high reliability and a large capacitance of 10 mu F for the Y5V characteristic and 4.7 mu F for the X7R characteristic, both in th e case of the C3216 (3.2 mm x 1.6 mm x 1.4 mm) form.