A review of thermal enhancement techniques for electronic systems

The demand for electronic components which will satisfy performance standards over a wide range of environmental conditions requires the use of thermal enhancement techniques. Recent thermal enhancement techniques for maximizing the thermal contact conductance, including greases, metallic foils and screens, composite materials and cements, and surface treatments are reviewed. The relative merits of the various enhancement techniques are summarized, and comparisons are made for selected thermal enhancement materials. For most electronic component uses, the use of greases poses a significant problem because of the potential for vaporization and/or migration to other surfaces in the component. The use of metallic foils and screens can provide thermal enhancement at an interface, depending upon the material properties as well as the contact temperature and applied load on the interface. There are a number of synthetic materials which can be used for thermal enhancement, and new materials are continuously being developed. Surface preparation or selected surface finishes can be used to enhance the heat transfer at an interface. Thin layers of vapor-deposited soft metals have been shown to improve the overall heat transfer at an interface significantly