Effect of Surface Roughness on Thermal Contact Resistance of Fixed Interface in Thermal Measurement of Electron Device

The interfacial thermal resistance between two solid materials is usually large, but there is still no way to eliminate it nor uniform measurement standard. Therefore, in thermal measurement technology, because the surface roughness of material directly affects the interface morphology, the change of total thermal resistance caused by the thermal contact resistance (TCR) fluctuations disturbs the accuracy of internal thermal analysis of the device. We prepared samples with different surface roughness and performed thermal measurements on them, compared with the test under vacuum environment and the condition filled with thermal interface materials, respectively. We found the heat transfer mechanism at the fixed interface. More importantly, it is shown that in the interval of surface roughness Ra < 6.4, the TCR shows good consistency when filled with thermal interface materials. This result will help to quickly improve the accuracy of thermal measurement technology.