Thermal analysis of base metal electrode multilayer ceramic capacitors

Multilayer ceramic capacitors (MLCCs) are a mainstay in modern electronics; they are utilized in consumer electronics, medical equipment, military devices, and electric vehicles, among others. As their range of usage increases, it is crucial to design MLCCs to withstand high-driving electric fields and high-temperature environments. Self-heating can occur in MLCCs wherein dissipative power loss raises their overall temperature beyond designed limits, deteriorating the reliability and performance. In this work, dissipation factors of 2220 case size C0G and X7R MLCCs were characterized as a function of temperature, frequency, and electric field amplitude. Furthermore, the self-heating and temperature rise of MLCCs under alternating current (AC) drive was investigated using optical thermography techniques and finite element analysis thermal modeling. It was found that the temperature increase in X7R MLCCs is 2–3 orders of magnitude higher than that of C0G MLCCs at 100 kHz, as is expected due to dissipation associated with domain wall motion in BaTiO₃. The self-heating behavior in X7R MLCCs was further investigated under various environmental conditions. It was found that the temperature rise of X7R MLCCs varies by 31%–37% and 25%–44% by changing the environmental temperature and thermal boundary conditions, respectively. In addition, the settling time to reach the steady-state temperature of a 15 nF X7R MLCC was observed to be 45 s for AC-induced self-heating and 99 s for cooling after the AC field was turned off.