Development of Thermal Resistance Evaluation Instrument by Flow Calorimeter

Abstract

In recent years, there is a demand for equipment that can evaluate the heat dissipation properties of metal base boards when designing the heat dissipation of electronic boards. We have developed instrument for evaluating the heat flow by a flow calorimeter. In this study, we verify the evaluation capability of thermal resistance by this evaluation instrument. In particular, in order to examine the performance on the low thermal resistance side compared to the conventional steady-state method, we measured multiple samples (Cu, Al, S50C, SUS304, SiO₂ glass) of with 40 mm square × 2 mm thick and 40 mm square × 5 mm thick. The thermal resistance dependence of the heat flow was qualitatively agreed based on the one-dimensional heat conduction model. It was found that if standard samples with known thermal resistance is used, the instrument using a flow calorimeter can detect thermal resistance of 1 × 10^-5 to 3 × 10^-3 m² K W^-1.