Thermal Characterization of Multi-Source Devices: Alternative Way to Determine the Thermal Characterization Matrix

Following the trend towards higher integration, more and more semiconductor devices integrate more than one active region (heat source) on one or several dies. The thermal characterization of these so-called multi-source devices is still being discussed and to-date there exits no commonly accepted standard procedure. The attempt to apply single-source thermal metrics to multi-source devices, e.g. by using only maximum device temperature and total power consumption to compute the thermal resistance, leads to further problems: E.g. thus calculated thermal metrics will only be valid as long as the ratio
$P_{1}:P_{2}:\ldots:P_{N}$
of power dissipation on
$N$
heat sources does not change. To avoid these problems the extension of the single source thermal metrics to a matrix of thermal resistances and transfer parameters as has been proposed by several authors. Usually this thermal characterization matrix (TCM) is obtained by heating only one source at a time and monitoring the temperature increase at the location of all heat-sources (including the one that is being heated). In this work we will demonstrate that the same matrix can also be obtained by applying almost arbitrary power dissipation patterns thus allowing to choose more realistic application scenarios for the thermal characterization of the multi-chip device.