High Power/Heat Flux Applications and Technologies

High power applications use heat spreaders to remove 50 to 500 Watts from 1cm x 1cm or 2.54cm x 2.54cm chips. High heat flux applications use heat spreaders to reduce heat fluxes of 100 to 1,000 W/cm²  by 10 to 100X. As shown in the figure (top right), a solid heat spreader is critical to these applications because the heat flux in the device level is too high to be manageable. Unfortunately, such a heat spreader is not effective even with a diamond substrate. As a result, the relatively high heat flux after spreading needs to be carried away by an expensive approach such as liquid cooling with impinging jets.  With Kelvin Thermal's TGP, we now have an opportunity to apply the extremely high evaporation heat transfer to aborb the high heat flux and spread the heat to a large area through vapor transport. Therefore, the expensive jet cooling is not required, and a simple liquid cooling or even air cooling scheme becomes possible.

As shown in the figure (bottom right), we have demonstrated a removal of heat fluxes up to 475 Watts from a 1cm x 1cm chip. It should be noted that the state-of-the-art vapor chambers could reach only 150 Watts from such a chip. For a larger module, e.g. 2.54cm x 2.54cm, we demonstrated a successful removal of 800 Watts in this experiment. With another configuration, we has improved the removal from 800 to 1,000 Watts with a much smaller temperature difference. For the larger chip or module, it was very challenging to supply liquid water to the center of the chip/evaporator region. The major advantage of Kelvin Thermal's TGP is that we applied an IP-protected multi-layer woven mesh to achieve such impressive heat flux removal performance. Even better, we improved the performance with manufacturable wicking structures. No nanotechnology is needed.  Design for manufacturability is always our guiding principle.

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