Metal and dielectric contact heat transfer and enhancement study using finite element approach

Thermal contact conductance (TCC) plays a vital role in improving the performance and the service life the electronic devices. As, the solid conduction paths through which the heat as to be dissipated includes multiple metal-metal and metal-dielectric contacts, which offers significant resistance to the rate of heat transfer. There exists a strong need for the estimation of TCC at the interface of metal-metal as well as metal-dielectric contacts. Majority of the studies relies upon experimental estimation, which is found to be expensive and challenging to perform in numerous electronics areas. The present work provides the 3D, finite element based micro contact thermo-mechanical simulation approach for the estimation of TCC between metal-metal and metal-dielectric contacts. The approach is compared against the steady-state experimental results and shows satisfactory agreement. The study has been extended further to analyse the effect of thermal interfacial materials (TIMs), the conductivity of TIMs, the thickness of TIM and load on contact heat transfer rate and TCC of metal-dielectric contacts. Present results have shown, the highest enhancements in contact heat transfer rates and TCC for TIMs with higher thermal conductivity and when the entire mean plane separation is filled with TIM of higher thermal conductivity. Finally, a model of TCC for metal-dielectric contacts has been established. Based on the methodology presented in this work, the design engineer can analyse the thermo-mechanical behaviour of specific pressed contacts under real operating conditions involving varying load, temperature as well as the interstitial materials at the junction.