Direct integration of dense parallel optical interconnects on a first level package for high-end servers

The direct integration of dense 48-channel parallel multiwavelength optical transmitter and receiver subassemblies directly onto a first level package using a flex lead attach has been demonstrated. Such an approach, at 10 Gb/s/channel would provide a linear edge bandwidth density of 300 Gb/s/cm. By attaching dense multichannel optical subassemblies directly onto an MCM, the performance limitations of the connectors and node card wiring can be avoided and the total bandwidth off the MCM can be increased while also enabling longer distance and higher speed signaling. This approach involves only a modest modification to the bent-flex approach commonly used for parallel optical modules intended for board mounting but enables a significant density and performance improvement for this application.