Contribution of sintering process to the reliability of X7R BME-MLCCs with high-voltage

The X7R (-55 °C - +125 °C, ≤ ±15%) BaTiO
3
-based base-metal-electrode multi-layer ceramic capacitors (BME-MLCCs) with high-voltage are in great demand in industry and their reliability as a crucial factor needs to be improved. In this study, we investigated the sintering parameters of different temperatures of 1280 °C, 1260 °C and 1253 °C and hydrogen atmosphere concentrations of 1% H
2
, 0.5% H
2
(S1, S2 and S3), and analyzed their influence on the reliability of the BaTiO
3
based high-voltage type BME-MLCCs. The mean grain sizes of the samples are 320 nm, 340 nm, 330 nm, respectively, which are generated by heat-treatment. S3 exhibits the best TCC characteristic of X7R and a highest level of reversible domains and irreversible domains among them from FORC investigations. High breakdown strength of 65.56 V/μm and 58.75 V/μm are obtained in S1 and S3 with high durable voltages over 100 V, directly resulting from the small grain size, high density and large insulation resistance. Moreover, the insulation resistance degradation measurement and HALT both indicate that S3 exhibits the best reliability due to the low oxygen vacancy content. The results indicate that a relative low sintering temperature of 1253 °C with a relative low hydrogen concentration of 0.5% is beneficial for the high reliability of MLCCs with high comprehensive performances.