Infiltration of water vapor into multi-layer ceramic capacitors under highly accelerated temperature and humidity stress tests

Abstract

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.

Hydrogen migration in BaTiO3-based dielectrics under high humidity and electric field bias

“…In previous studies, it was presumed that when water vapor infiltrated the interface between the anode-side inner electrode and the dielectric, electrolysis occurred at the interface, as shown in the equation below, and D + was attracted to the cathode-side inner electrode by migration through the dielectric. [23][24][25] Considering the results of Fig. 3(a) and the aforementioned presumption, the deuterium in the dielectric is presumed to exist as D +…”

“…Consequently, the leakage current increases as the protons diffuse into the dielectric. 23) It was verified that water vapor infiltrates the MLCC 24) using deuterium, as a tracer. It was observed, that deuterium was biased toward the cathode-side inner electrode in the BaTiO 3 -based dielectric exhibiting increased leakage current.…”

“…From the results of previous studies, [23][24][25] it was presumed that protons migrate because they are attracted from the anode side to the cathode side. In this study, secondary ion mass spectrometry (SIMS), which can analyze deuterium with a high degree of sensitivity, was used to understand deuterium migration due to the electric field and temperature.…”

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

“…The protons then diffuse into the dielectrics, thereby increasing the leakage current. 23,24) Numerous researchers have studied the relationship between perovskites and hydrogen. Waser et al reported the solubility and diffusion of hydrogen defects in perovskite.…”

“…30) Using secondary ion mass spectroscopy (SIMS) analyses and complex impedance measurements, Morito et al confirmed that protons dissolved the interstitial hydrogen impurity in (Ba, Sr)TiO 3 thin films annealed at 400 °C. 31) Although we previously clarified vapor infiltration into an MLCC in a HAST, 24) hydrogen infiltration into BaTiO 3 -based dielectrics between the internal electrodes in the active layer of the MLCC has not been clarified, and the cause of the increase in the leakage current is debatable.…”