Improved lifetime reliability of MLCC against water vapor by forming an interfacial alloy between internal and external electrodes

Voltage, temperature, and humidity are typical stressors used in high accelerated life testing (HALT) of multilayer ceramic capacitors (MLCCs). Especially in the case of humidity, there is no initial insulation resistance (IR) change and no IR degradation during HALT, indicating that the failure mechanism causing lifetime acceleration for humidity is different from voltage and temperature. This study confirms that there is no IR degradation during HALT against humidity, as protons generated by electrolysis of infiltrating water vapor at the anode electrode cause IR degradation through proton migration in a very short time. In addition, the water vapor-induced failures were caused in the region between the internal and external electrodes. Sintering in a low reducing atmosphere can inhibit these failures by forming an alloy between electrodes to maintain the film shape. Furthermore, the stretched exponential fitting method accurately accelerates specific water vapor-related failure modes when all MLCC lifetime modes coexist.