Integrating nano carbontubes with microchannel cooler

Abstract

Providing effective and compact heat removal solutions is an essential element of the electronics packaging approach and its importance increases as the trend in the electronics industry moves towards higher packaging density and more severe operation conditions. Many new thermal removal techniques have been developed in response to this situation, among which microchannel liquid cooling systems have been considered as one of the very promising cooling solutions. Its major advantage includes the high heat transfer coefficient and possible wafer-level integration with chips. However, the high-pressure drop associated with microchannel flow prevents it to be employed in a fluid loop with micro-pump due to the pumping power limit. Enhancing the thermal exchange rate between substrate and coolant is a straightforward method to overcome this problem. The present work proposes two plausible methods to integrate high-thermal conductive nanotubes with existing microchannel coolers for enhancement in cooling capability. The first one is to replace the silicon fins with nanotube fins. Since nanotubes have extremely high thermal conductivity, the pin-to-coolant temperature difference can increase further and more heat can be transferred to the coolant. The second method is to grow aligned nanotubes on the whole thermal exchange surface of the groove where the coolant flows. Each nanotube stands separately and acts as a tiny pin, which dramatically increases the thermal exchange area. The theoretical part consists of a preliminary numerical study to determine the highest possible heat transfer capability of the nanotube enhanced microchannel cooler and how its performance is affected by geometrical parameters like channel width and length.