Abstract
Precise thermal management is necessary for high heat flux in SiP-mounted semiconductor devices. The purpose of the present study is accurate evaluation of thermal resistance change on the Flip-Chip junction structure in those devices. To measure microscale thermal resistance, we applied a photothermal reflectance method. In this method, thermal properties are extracted from a phase-lag between heating and temperature oscillation at the sample surface, using lasers. We theoretically verified that the phase-lag has adequate measurement sensitivity, and then developed a new measurement apparatus. We measured thermal resistance of Si wafer, confirming that the apparatus operates according to the measurement theory. Furthermore, we preliminary measured interfacial thermal resistance between Si wafer and Au foil.
