New packaging techniques for opto-electronic multichip modules (OE-MCMs), including OE substrates and optical coupling between a waveguide and a flip-chip bonded photodevice or fiber, are presented for high-speed and wide-band communication systems. The OE substrates, which offer high-density, high-speed optical and electrical interconnection, are made from low loss (0.4 dB/cm) optical polyimide waveguides fabricated on copper-polyimide electrical multilayer substrates. A total internal reflection mirror fabricated at the edge of the optical waveguide reflects the light propagating from the waveguide to a flip-chip bonded photodiode with a loss of less than 1.5 dB. The waveguides are coupled to fibers for inter-module interconnection using the self-aligning fiber guiding method.