Electrothermal simulation of barium titanate based PTCR thermistor

PTCR thermistors are thermally sensitive resistors that show positive temperature coefficient of resistance and are good candidates for applications as self-regulating heating elements and thermal control switches. For these applications, the current-time behavior of thermistors is of primary importance. In this work, heat transfer models were developed to simulate the electrothermal behavior of BaTiO3 thermistors. Also, using simulated temperature profiles, thermal stress distributions of the specimen were calculated to predict crack formation at different conditions. At high voltages, the effects of thermal conductivity and heat transfer coefficient were negligible. At low voltages, the effects were pronounced and increased the response time. High thermal conductivity decreased the thermal stress, but high heat transfer coefficient increased the thermal stress.