Evaluation of the Heat Transfer Coefficient in Microcircuits From the Frequency Analysis of the Thermal Transient Response

In this paper, it is outlined how thermal AC measurements can be carried out on a resistor deposited on an electronic substrate. The AC approach enables us to limit ourselves to phase measurements which can be carried out with a much higher precision than amplitude measurements. It will also be demonstrated how the phase measurements at a well-chosen frequency can be used to measure the heat transfer coefficient.