Compact thermal model for HBT devices

A compact thermal model has been developed to accurately (within 5%) predict the thermal resistance of HBT arrays. The HBT power sources are modeled as spherical heat sources. The temperature distribution and hence the thermal resistance of a single device is modeled first. Method of translation that takes advantage of the linearity of the heat transfer equation is then used to calculate the temperature distribution of an array of devices. The compact model is valid for the typical ranges of die attach thickness and thermal conductivity used. The method has been validated using finite element simulations. The accuracy of the model is also verified using experimental results presented. InGaP/GaAs based HBTs were used for measurements