Fumihiko Shimizu

Optical parallel interconnection characteristics of 4-channel 2-Gbit/s bit synchronous data transmission module

A simple 4-channel 2-Gb/s optical parallel interconnection module, allowing a bit synchronous data transmission over a distance of 100 m, has been fabricated. This module employs a lensless optical coupling system between 4-arrayed LD/PD and ribbon fiber, which requires no careful optical axis alignment by using the silicon micromachining technique and an MT (mechanically transferrable) connector. The optical transmitter and receiver are fabricated using the hybrid mounting technique on copper-mount backed polyimide multilayer substrate. This mounting technique can enhance the heat transfer, high-frequency, and skew characteristics. The module can be applicable to intra- and for inter-cabinet interconnections of 2-Gb/s data without any bit synchronizing circuit.<<ETX>>

Multichip module technology using AlN substrate for 2-Gbit/s high-speed switching module

The authors describe a multichip module (MCM) technology for making broadband digital switching modules. A copper/polyimide thin-film multilayer substrate is developed to achieve high-speed digital transmission. The substrate is formed on an aluminum nitride ceramic (AlN) wafer with good thermal characteristics. The meshed strip-line structure is used to control the characteristic impedance for 50- Omega signal lines, and the thin-film termination resistors are made of NiCr to prevent reflections. With this technology, the authors experimentally fabricated a broadband digital switching module, which is constructed from switching ICs in bare dies, clock distributing ICs in flat lead packages, and chip/micro-chip capacitors. In this module, differential digital transmission lines are adopted for high-speed signals to reduce the crosstalk noise effect. Heat generated from the module, which has a total of 25 W of power dissipation, is efficiently conducted through the AlN wafer. This module can operate many 2-Gbit/s high-speed channels. A novel multichip module technology for high-performance systems was successfully developed.<<ETX>>