To cope with the extreme power density limits for high performance systems and high-power devices, conventional microchannel cooling solution needs to go to much smaller channel hydraulic diameter to achieve higher heat transfer coefficient. However, the pressure drop will increase dramatically as the channel dimension becomes smaller and smaller. Moreover, there will be temperature gradient along the channels since the liquid will be heated up as it flows along the channels. The temperature nonuniformity will result in thermomechanical stress reliability issues. Those are not efficient for the electronics cooling. In order to address those challenges, high-efficiency direct liquid jet impingement cooling solution utilizes microscale 3D hierarchical fluid delivery systems with alternating N x N inlet/outlet nozzles jets array, enabling the spent fluid to be efficiently extracted through the outlet nozzles that are distributed in between the inlet nozzles. This local outlet flow extraction approach requires low pressure drop due to the short liquid flow transfer length from the inlet and outlet. The repeated inlet/outlet nozzles array can also achieve much better flow and temperature uniformity. Alternatively, embedded microchannel cooling with top accessed 3D manifolding structures (EMMC) can also address the challenges. The 3D manifold structures can provide multiple inlets and outlets along the embedded microchannels, that can short the fluid flow path and further reduce the pressure drop. We will explore the surface enhancement method and two-phase cooling for the different microfluidic cooling solutions.

Innovative thermal/fluidic cooling solutions: (a) impingement jet cooling with alternating inlet and outlet jets; (b) embedded microchannel cooling with 3D manifold structure.

Methodologies for developing chip-level/package-level thermal management solutions for different applications.