High performance liquid metal thermal interface for large volume production

Abstract

Thermal Interface Materials (TIMs) between microprocessors and heat-sinks are crucial for cooling high performance components at today's power levels. The focus of TIMs for high power processors has been a thin highly conductive and inert layer that can withstand the thermal expansion mismatch between silicon chips and copper based lids or heat-sinks. This work focuses on a Liquid Metal Thermal Interface (LMTI) developed for high volume production in computer systems. Compared to the best polymer thermal interface, LMTI boosts the interface conductivity by an order of magnitude. It also minimizes issues of mechanical compliance and load. The paper examines performance of LMTI and reliability aspects that include providing good wetting of the liquid and protection from oxidation and corrosion. It also presents examples of temperature gains obtained with LMTI in actual products, as well as a demonstration of cooling capability in excess of 750 W/cm2 obtained in conjunction with a water cooled heat-sink.