Microfluidic Cooling for 3D-IC with 3D Printing Package

Microchannel cooling method for stacked 3D-IC has process and cost issues. The proposed method, the thermal fluid chamber, exploits the gap between the upper and lower stacks. The method advantages are achieving controllable coolant flow and low-cost process. The microfluidic cooling system is composed of a thermal test chip, thermal test board, 3D printing package, and microfluidic apparatus. The thermal test chip with C4 micro-bumps is attached on the test board. The thermal generator and sensor in the chip are operated by the test board. The microfluidic chamber of 68 μm thick is integrated between the chip and board. Thermal sensing and microfluidic tests demonstrate the validity of the thermal fluidic chamber.