Thermal characterization of multi-die packages

Thermal measurement and modeling of multi-die packages became a hot topic recently in different fields like RAM chip packaging or LEDs and LED assemblies. In our present study, besides the overview of usual multi die packages, we present results for a more complex structure: an opto-coupler device with 4 chips in a combined lateral and vertical arrangement. The paper gives an overview of measurement and modeling techniques and it describes actual measurement results along with our structure function based methodology which helps validating the detailed model of the package being studied. Also, we show how one can derive junction-to-pin thermal resistances with a technique using structure functions