Assessment of TEC Thermal and Reliability Requirements for Thermoelectrically Enhanced Heat Sinks for CPU Cooling Applications

The microelectronics industry is reaching the limits of traditional air cooling for many applications, particularly for gaming computers and high-end workstations. The continuing trends toward smaller die and higher heat dissipation lead to higher watt densities and large thermal interface losses. This forces the thermal designer to utilize more and more efficient heat sinks because a significant portion of the die to ambient DeltaT is consumed by interface and spreading losses. The use of thermoelectrics, operating at COPs between 2 and 4, can be an effective means of enhancing or augmenting the thermal performance of air-cooled heat sinks and has been documented at recent thermal management conferences. These publications have focused on the potential improvement in heat sink thermal performance possible from TE enhanced heat sinks for CPU cooling applications. Little work has been published discussing the requirements of the TECs necessary to achieve these performance improvements. This paper will review recent publications detailing the thermal performance improvements possible utilizing thermoelectrically enhanced heat sinks and will address the TEC design and performance criteria. Reliability requirements for CPU applications will also be discussed along a reliability assessment of TECs operating in typical CPU cooling environments