New optical and electrical hybrid packaging techniques using optical waveguides for optoelectronic multichip modules

An optoelectronic multichip module (OE-MCM) using fluorinated polyimide optical waveguides is proposed, This module can be produced with an optoelectrical substrate (OE-substrate), incorporating photodiode-to-waveguide coupling, and fiber-to-waveguide coupling, The OE-substrate is composed of fluorinated polyimide optical waveguides fabricated onto a copper-polyimide multilayer electrical substrate, Propagation loss of the optical waveguide is low at 0.4 dB/cm, There is no change in the optical characteristics of the waveguide after heat-treatment during the solder bonding process, The waveguide-to-photodiode coupling is achieved by deflecting the propagating light with a total internal reflection (TIR) mirror, and self-alignment of the photodiode is achieved using micro-solder bumps, The TIR mirror shows low reflection loss of less than 1.5 dB, The solder bumps can position the photodiode accurately within +/-1 mu m, A fiber guiding groove is used for alignment-free coupling between inter-modules, The coupling toss between the fiber and the waveguide is estimated to be 3.2 dB with the deviation of about 0.1 dB, These techniques make OE-MCM's attainable.