thermal characterization, modeling, and optimization
of thermally-enhanced polymer composite heat sinks

dr. avram bar-cohen

therpes laboratory
department of mechanical engineering
university of maryland

increasing electronic product manufacturing volumes and cooling requirements necessitate the use of new materials and innovative techniques to meet the thermal management challenges and to contribute towards sustainable development in the electronic industry. thermally conductive polymer composites, using high thermal conductivity fillers such as carbon fibers and carbon nanotubes, are becoming commercially available and provide favorable attributes for electronic heat sinks, such as low density and fabrication energy requirements. these polymer composites are inherently anisotropic but can be designed to provide high thermal conductivity values in particular directions to address application-specific thermal requirements.

this presentation will offer a systematic approach to the characterization, analysis, design, and optimization of orthotropic polymer composite fins used in electronic heat sinks. morphological characterization and thermal conductivity measurements of thermally conductive poly-phenylene sulphide composites are used to determine the significant directional thermal conductivity in such composites. an axisymmetric orthotropic thermal conductivity pin fin equation is derived to study the orthotropic thermal conductivity effects on pin fin heat transfer and temperature distribution. theoretical models, cfd modeling, and experiments are used to characterize the thermal performance of heat sinks, fabricated of pps composite pin fins, in air natural convection and forced convection modes. simplified solutions, for the orthotropic fin heat transfer rate that are easy to use and can be easily implemented in a heat sink design and optimization scheme, are also presented.