Fraunhofer Institute for Ceramic Technologies and Systems IKTSHeat flow sensors are used to quantitatively measure heat flow, i.e., heat transfer, in various applications. They are crucial for energy monitoring, as they precisely measure energy consumption in heating, ventilation, and air conditioning systems and provide insights into the thermal efficiency of industrial processes. In research and development, they enable the investigation of heat transfer mechanisms (heat conduction) and their characterization in various materials and systems. One example is the optimization of battery thermal management.
For this application, Fraunhofer IKTS, in collaboration with an industrial partner, has developed a heat flow sensor with gold-platinum thermocouples in ceramic multilayer technology. The uniform measuring cell consists of an Au-Pt thermocouple embedded in a ceramic carrier material and constructed by multiplication into a larger monolithic sensor (thermocouple chain). A reference resistance thermometer was integrated to measure the ambient temperature.
A Pt via paste (Viafill) was developed at IKTS specifically for the Au-Pt thermocouple, enabling the multilayer construction of this heat flow sensor. The focus was on adapting the shrinkage behavior of the via paste to the shrinkage of the LTCC material and on forming a defect-free structure during co-firing.
