Advanced copper-based composites filled with phase-change materials for new thermal-management applications

Phase change materials (PCM's) like paraffins or salty compounds are able to absorb and to release reversibly huge amounts of latent heat between the solid and liquid state These materials represent latent heats of about 150-250 kJ/kg at discrete temperatures and, therefore, they can preferably be applied to the storage of industrial waste heat and solar heat. However, such PCM's are also very interesting for cooling and tempering of electronic components because typical PCM's possess their phase change temperatures between -15 deg C and 190 deg C. Ideal materials for heat sink application should have a high thermal conductivity but also an optimised heat capacity. A combination of metals like copper with PCM's as composite material could result in the desired properties. Such composites serve for smoothing and prevention of temperature spikes caused by cyclic switching operations of power electronics. An appropriate PM technology to manufacture this new material will be presented. A relationship between microstructure, the material properties and the performance of the PCM-filled copper composite will be displayed.