In this paper, we discuss the problem of electropurpose Maxwell solver for the derivation of equivalent circuits of various components of a package that can be inserted in a SPICE-type circuit simulation program to investigate the electrical performance of the package. The solver is based upon the finite difference time domain (FDTD) algorithm, and its usefulness is illustrated via the application to a number of representative problems.On the packages, the high-frequency effects are no longer dure, which have appeared in numerous publications, will be omitted here. Basically, in the FDTD algorithm, Consequent1Y7 frequencY-dePendent [61. However, these high-frequency extensions often redifference form of Ampere's and Faraday's laws are &own E,( I , J , K)""