3-D electronic interconnect packaging

A packaging concept is presented that supports three-dimensional (3-D) interconnect of digital electronics using a stacked multichip module (MCM) approach. The 3-D structure offers an order of magnitude improvement in global communication bandwidth over traditional backplane techniques. This is accomplished by simultaneously reducing interconnect length (propagation delay) and dramatically increasing physical connectivity between layers of electronics. A characterization cube is described that will demonstrate the key technologies behind the 3-D packaging concept. These include synthetic diamond substrates for heat conduction, spray cooling for heat removal, double-sided multi-layer MCM interconnect, and high density connectors that support the required inter-layer signal bandwidth. Size and weight benefits of 3-D packaging are quantified in a specific application comparison. Results suggest that machines normally confined to a computer room environment can be repackaged with this technology for airborne, shipborne, or mobile applications.