This paper presents a simple and robust method of designing the lossy-transmission-line interconnects in a network for multichip modules. This method uses wire-sizing entirely to meet the electrical damping criteria to solve the problems encountered in propagating highspeed signals through unterminated lossy transmission lines on the substrates of multichip modules (MCM). The optimal design method is based on a new improved scatteringparameters (S-parameters) based macro-model of distributed-lumped networks that keeps track of the time-of- ight term in the transfer functions. The wire-sizing optimal design concept is to relate the layout parameter (line width) and the transfer function (damping ratio, and natural undamped frequency) to the signal propagation delay. The optimal design method results in fast and stable signal propagation for single-source multi-receiver networks on multichip modules without using termination resistors. Multi-receiver networks on High Performance MCM pro...