Frequency Domain Diakoptics for IC Packaging Structures Based on the PEE and FDTD Methods(Special Issue on Microwave and Millimeter-Wave Module Technology)

This paper describes a diakoptics approach to the field simulation of shielded structures. If the structure can be divided so that the sliced cross section is homogeneously filled with a medium in the metal-surrounded region, the frequency domain diakoptics can be effectively formulated. In the method, the partial eigenfunction expansion(or modal expansion)is utilized at the interface between the divided structures, and the finite difference time domain calculation is used to characterize some of the divided parts. The synthesis of total characteristics is demonstrated using a simple example. The issue of term truncation in the eigenfunction expansion is also addressed and an effective algorithm for the term selection(mode selection)is proposed. The techniques described here are applicable to metal package designs for efficient structure optimization.