Peak Temperature Limitation of Electronic Assemblies with Phase Change Materials
Authors: Mathias Nowottnick, Andrej Novikov, Daniel Lexow Company: University of Rostock Date Published: 9/27/2015
Abstract: Electronic components and assemblies, e.g. for power electronics, are able to generate a lot of power loss and heat as well. Especially temperature peaks and extreme temperature changes are the cause for stress, which has a negative effect on the reliability and achievable lifetime. For such demands, it is necessary to derive the excess heat as quick as possible in order to avoid hot spots with critical operating temperatures. For this purpose, a considerable effort is often required by heavy heat sinks, noisy fans or hard to maintain liquid coolers. If the environment is hot as well, e.g. for deep drilling equipment, these measures are even useless. For the limitation of short-term temperature peaks it should be sufficient to redistribute the heat locally. The idea is to use the enthalpy of melting materials, so called phase change materials, for the redistribution of heat in a coating or molding. Whereas this effect is already used for other applications, it was necessary to find suitable materials adapted for electronic assemblies. Apart from an appropriate melting temperature and a maximum heat storage capacity, the material shall not affect the electrical function of the electronic circuit. Moreover, the material should be as cost-effective and easy to apply. By various combinations of materials, the required properties can be optimized. It is shown on selected components, how such coatings are limiting effectively the temperature peaks and reduce the temperature differences.
thermal management, phase change material, cooling, power electronics