SUMMARY

Both 2.5 dimensional (2.5D) and 3 dimensional (3D) stacked chip heterogeneous architectures are promising to go beyond Moore's law for compact, high-performance, energy-efficient microsystems. These systems face significant thermal management challenges due to the increased volumetric heat generation and reduced surface area. In addition, highly spatially and temporally non-uniform heat generation occurs due to different functionalities of various chips. In this dissertation, pin-fin enhanced microgap configuration has been investigated under transient and steady state conditions for single phase liquid cooling, and flow boiling. Multi-chip test structures have been studied using computational modeling and experiments. Modeling approaches include compact models, and highly resolved computational heat transfer and flow simulations. Experimental characterization included heat transfer, and high speed flow visualizations.