Applications of temperature phase measurements to IC testing

International audienceThis work analyses the applicability of silicon surface temperature phase measurements as a test observable when a device acting as a heat source dissipates a modulated power function. Specifically, this paper considers two different functions: the phase shift of the temperature waveform as a function of frequency and distance, and the slope of the temperature phase shift versus distance as a function of frequency. Different cases are analyzed in order to show the potential of both functions, including experimental results obtained from a specific integrated circuit (IC). The conclusions will show that samples of the phase function can be used to locate devices acting as heat sources, and that the slope function can be used to extract information regarding the heat flow path in the IC, and, therefore, regarding the structure of the IC