A generic methodology for deriving compact dynamic thermal models, appliedto the PSGA package

A novel methodology for synthesizing compact, boundary condition independen t, dynamic thermal models is represented, The resulting compact resistor/ca pacitor network accurately predicts the dynamic junction temperature respon se under any arbitrary set of external cooling conditions, The network is d erived in two successive steps. First, a boundary condition independent res istor network is synthesized using steady-state finite element data for a l arge set of practical boundary conditions, Next, the general resistor netwo rk is expanded with discrete thermal capacitors featuring the thermal mass of the package. The value of the capacitors and their exact location within the resistor network is determined using frequency response finite element data for a limited set of boundary conditions, This paper focuses primaril y on the second step, i.e., synthesis of the dynamic (capacitive) network e lements, The synthesis method is successfully demonstrated for two types of polymer stud grid array (PSGA) packages, the standard PSGA and the thermal ly enhanced PSGA, It is shown that the thermal mass of a PSGA package can b e lumped into five discrete thermal capacitances, For both the standard and the thermally enhanced PSGA, the generic compact dynamic network models ca n predict time dependent junction temperature profiles within an accuracy o f 5%.