Multichip 1.8-Gb/s high-speed space-division switching module using copper-polyimide multilayer substrate

A high-speed multichip 32×32 space-division switching module for high-definition TV broadcasting and switching systems is described. This module employs a novel Si-bipolar SST (super self-aligned process technology) switching LSI and a multilayer substrate with a polyimide dielectric and a fine pattern of copper conductors. The substrate contains matrix-shaped thin-film resistors for terminated transmission and has a spiral via hole structure to increase fabrication reliability. The module has 50-Ω characteristic impedance transmission lines that have a small deviation of less than 2.5%. The multichip module can handle a signal speed of 1.8 Gb/s using 1:1 and 1:n connections. Performance results confirm that this module will be suitable for future B-ISDN (broadband integrated services digital network) communication systems