3D Integrated Architectures for Microelectronic Two-Phase Flow Cooling Applications

viii transfer coefficient in the channels, which is effective in flattening thermal gradients from non-uniform heating within the chip stack. Flow boiling of refrigerants 236fa and 1234ze (R236fa & R1234ze) were experimentally investigated within two different test sections. First-of-a-kind high pressure fluidic tests were successfully achieved within a 3D chip stack with interlayer cooling capabilities and high aspect ratio TSVs. However, fabrication defects and a scarce amount of TSV wafers rendered the heat transfer study within the chip stack impossible. Finally, pressure drop measurements and local junction temperatures were measured on a 2D silicon pin fin test section as a potential candidate for future 3D modules. A good cooling performance was demonstrated, with a junction temperature response of 40°C for a base heat flux of 66.6 W/cm2. The observed high pressure drops were a result of the very small flow crosssectional area.