Numerical methods have been widely used in extracting parasitic parameters for power modules, such as the boundary element method (BEM), partial element equivalent circuit method (PEEC), and finite element method (FEM), etc. This paper proposes a parasitic extraction method for fast-switching multichip power modules using the frequency-domain FE A-Phi formulation. It can extract frequency-dependent YZ parameters in a single solver and convert the YZ parameters into a multiport electrical network that can then be used in system-level circuit simulations. The A-Phi formulation allows flexible excitation assignment, partial conductor modeling, simultaneous consideration of inductive and capacitive effects, and stable solving from very low frequencies close to DC to high frequencies up to GHz, making it a suitable 3D FEA formulation for parasitic extraction of power modules compared to other formulations. It can also be used for broadband parameter extraction of power magnetics considering material property nonlinearity and frequency dependency.
