Galerkin's Projection Framework for BCI CTMs - Part I: Extended FANTASTIC Approach

A general Galerkin's projection framework is proposed for the definition of boundary condition independent (BCI) compact thermal models (CTMs). First, it is shown how the proposals of BCI CTMs, deriving from the works of Bar-Cohen and Sabry, can be straightforwardly reinterpreted within this framework. Then, following such reinterpretation, the approach due to Lasance, nowadays widely adopted for the extraction of BCI CTMs, is generalized into a novel approach, based on the extension of the previous FAst Novel Thermal Analysis Simulation Tool for Integrated Circuits (FANTASTIC) method, from the fixed boundary conditions case to the BCI case. Such an approach allows widely enlarging the set of boundary conditions for which a BCI CTM ensures accuracy and allows overcoming the main limitations of previous approaches, e.g., with multisource problems and dynamic models.