The failure mechanisms of multilayer ceramic capacitors (MLCCs) with Ni internal electrodes under high temperature and high voltage conditions have been investigated through highly accelerated life tests (HALTs) in recent years. Generally, insulation resistance degradation during HALTs is presumed to be because of the electromigration of oxygen vacancies. Reliability in high-temperature, high-humidity, and rated-voltage environments is important for MLCCs. However, only a few studies have investigated the causes of insulation resistance degradation in MLCCs in these environments. We investigated the failure mechanisms of MLCCs through a highly accelerated temperature and humidity stress test. On the basis of presence of a degraded area on the anode side, we presumed that hydrogen ions were produced by H 2 O electrolysis at the interface between the ceramics and internal electrodes on the anode side, and that these hydrogen ions caused insulation resistance degradation.

Although it has been suggested that infiltration of water vapor into multi-layer ceramic capacitors (MLCCs) can increase leakage current, few studies have reported how this increase is directly linked to the infiltration. In this work we performed accelerated temperature and humidity stress tests with heavy water as a tracer and investigated, using secondary ion mass spectrometry, whether traces of water vapor could be detected in MLCCs. In particular, deuterium was found in areas where an augmented leakage current was detected. It is clear that infiltration of water vapor into MLCCs increased the leakage current. This finding could lead to further improvements in MLCCs.

To make electrical devices, such as smartphones and automotive devices, more functional, the mechanism of electrical reliability in multi-layer ceramic capacitors (MLCCs) under high temperature, high humidity, and electric field bias environments has been studied. Although it has been presumed that hydrogen influences this mechanism, it is difficult to analyze hydrogen itself. Therefore, we investigated BaTiO 3 -based dielectrics in which the leakage current increases by conducting highly accelerated temperature and humidity stress tests using heavy water (D 2 O) as a tracer instead of light water (H 2 O) and secondary ion mass spectrometry analysis. We report the detection of deuterium in the dielectrics between the inner electrodes where the leakage current increased, and deuterium was biased toward the internal electrode on the cathode side. These findings can help further improve the reliability of MLCCs.

This study investigates the possibility of hydrogen migration in BaTiO3-based dielectrics to improve the electrical reliability of multi-layer ceramic capacitors under conditions of high temperature, humidity, and electric field bias. It was observed that the deuterium in the dielectric drifted and migrated with the electric field, suggesting that deuterium exists as D+. The activation energy was found to be 0.34 eV, which is lower than that observed in previous studies. This finding offers a better understanding of the mechanism behind the migration of deuterium in a dielectric, which is highly relevant to future research in dielectrics and electronic components.