FINITE-DIFFERENCE TIME-DOMAIN ANALYSIS OF PULSE-PROPAGATION IN MULTICHIP-MODULE INTERCONNECTS

The application of the finite-difference time-domain (FDTD) method to the electromagnetic characterization of multichip-module (MCM) interco nnects with perforated (mesh) reference planes is demonstrated. The li mitations of the method in finding transmission line propagation chara cteristics (i.e., characteristic impedance Z0 and phase constant beta) are investigated. An alternative approach for the characterization of MCM interconnects is suggested which exploits the capabilities of the FDTD method. This alternative approach uses the results from the FDTD method to extract a per unit length delay and an approximate impulse response of the system. These results can be used to identify the effe cts of the perforated reference plane on signal propagation. The valid ity of the TEM approximation for signal propagation in realistic MCM s tructures is also examined.