High power multichip modules employing the planar embedding technique and microchannel water heat sinks

This paper describes a novel packaging technology for high power multi chip modules (MCMs). The work covers three areas: The fabrication of a multichip module which provides access to the die backside for heat removal, the development of high performance microchannel heat sinks with a CTE matched to the MCM-substrate as well as a low thermal resistivity assembling technology of the two components. The MCM is fabricated by means of the planar embedding technology. By planarizing the module backside a low thermal resistance between heat sink and dice can be accomplished simultaneously for all embedded components. While offering the same high interconnection density and the high speed performance benefit of flip chip and providing high reliability and very small size of the overall package, this alternative technology promises to eliminate crucial problems associated with backside cooling of flip chip devices.