Recursive metal embedded chip assembly

Abstract

A recursive metal-embedded chip assembly (R-MECA) process and method is described for heterogeneous integration of multiple die from diverse device technologies. The recursive aspect of this integration technology enables integration of increasingly-complex subsystems while bridging different scales for devices, interconnects and components. Additionally, the proposed concepts include high thermal management performance that is maintained through the multiple recursive levels of R-MECA, which is a key requirement for high-performance heterogeneous integration of digital, analog mixed signal and RF subsystems. At the wafer-scale, chips from diverse technologies and different thicknesses are initially embedded in a metal heat spreader surrounded by a mesh wafer host. An embodiment uses metal embedding on the backside of the chips as a key differentiator for high-density integration, and built-in thermal management. After die embedding, wafer-level front side interconnects are fabricated to interconnect the various chips and with each other. The wafer is then diced into individual metal-embedded chip assembly (MECA) modules, and forms the level one for multi-scale R-MECA integration. These modules are subsequently integrated into another wafer or board using the same integration approach recursively. Additional components such as discrete passive resistors, capacitors and inductors can be integrated at the second level, once the high-resolution, high-density integration has been performed at level zero. This recursive integration offers a practical solution to build very large scale integrated systems and subsystems.