Establishment and simulation study of equivalent model for thermal contact resistance in electronic devices

To accurately determine thermal contact resistance (TCR) for the thermal design of electronic devices, a simplified simulation method is first proposed for calculating thermal contact resistance. First, an equivalent geometric model is established based on actual rough surfaces Then, finite element methods are employed to calculate the thermal contact resistance. The results demonstrate that the proposed equivalent geometric model, containing contact point information, can accurately predict the thermal contact resistance, which has a deviation of 10% with the experimental data. Furthermore, the results revealed that both the contact pressure and the surface roughness of the materials significantly influenced TCR, through adjusting the gap thickness. As the contact pressure increased from 200 to 1400 kPa, the TCR decreased from $6.96\times {10}^{-4}$ to $4.39\times {10}^{-4}{m}^2·\hspace{0.17em}°C·W^{-1}$. The decrease became more gradual at high contact pressure, indicating a nonlinear relationship between pressure and TCR. On the other hand, the surface roughness affected TCR primarily through the equivalent contact point height, that is, the gap thickness between two samples. Moreover, temperature affected TCR mainly through radiative heat transfer, which was dependent on material intrinsic properties. The developed simplified calculation method can efficiently simulate TCR for electronic devices, which not only enhanced the understanding of TCR behaviour but also provided a practical tool for optimizing thermal designs in electronic devices.