Hydrogen infiltration into BaTiO3-based dielectrics for multi-layer ceramic capacitors under highly accelerated temperature and humidity stress test

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 BaTiO3-based dielectrics in which the leakage current increases by conducting highly accelerated temperature and humidity stress tests using heavy water (D2O) as a tracer instead of light water (H2O) 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.