High speed multichip modules using flip chip mount technology for 10 Gbps optical transmission systems

This Paper describes small-sized multichip modules (MCMs) for 10 Gbps optical transmission systems. We have developed three kinds of MCMs. MCMs include LSIs we have newly developed by employing SiGe bipolar process. Each kind of MCM is composed of an alumina substrate with flat lead frames, LSIs mounted by flip chip mount technology, passive SMT components, and a heat spreader. To achieve wide-band characteristics of MCMs, the grounded coplanar waveguide design is adopted for the transmission lines on MCMs. The heat spreader is attached to the backside of each LSI through thermally conductive silicone compound for highly effective cooling. These MCMs have been applied for our 10 Gbps optical transmitter and receiver modules in the wavelength division multiplexing (WDM) system, and achieved 1.6 Tbps (10 Gbps/spl times/160 channels) of transmission capacity.