O/e-MCM packaging with new, patternable dielectric and optical materials

This paper presents a novel o/e-MCM-L/D concept for fully integrated opto-electronic MCM-packaging aiming at: very low cost, very high interconnect density and high performance. The polymer thin film materials technology allowing the integration of optical waveguides and high density electrical interconnects in just 3 thin film layers is also discussed in terms of chemistry, processes and properties. Very good processability and planarization of the new inorganic-organic photo-polymers, ORMOCERs, (ORganically MOdified CERamics) in combination with a much lower post-curing temperature (120°C-170°C) than alternative materials (such as polyimide and benzocyclobutene) enables the use of low cost polymer substrates such as FR-4 epoxy. Novel surface mountable waveguide-connectors for passive precision alignment, compatible with standard MT-opto-connectors can be used for coupling light in and out from the o/e-MCM-L/D´s. In the demonstrator, laser-arrays (VCSEL´s) and photodiode-arrays are flip-chip mounted above UV-excimer laser ablated 45-degree mirrors in the waveguides. Driver-chips and passive components are wirebonded and surface mounted respectively. The modules are also supplied with microvias in the FR4-epoxy-substrate connecting to a ball grid array (BGA) underneath. The need of any extra package for connection to next packaging level is thus eliminated. In conclusion the versatility and the low-cost potential of the presented technologies are emphasized