The heat dissipation performance of point-contact structures in many micro/nano-devices is critical. In this study, the effects of the normal load and diameter of the silicon ball on the effective thermal contact conductance (G_eff) of the encased silicon ball between two silicon plates were studied by using the non-equilibrium molecular dynamics method. The results show that increasing the normal load increases the real contact area between the silicon ball and silicon plate, and thus improves the transmission channel and the density of states of low-frequency phonons, resulting in the observation that the G_eff increases with increasing normal load. It is also found that the G_eff is not sensitive to the diameter of the silicon ball from 2.66 to 4.16 nm at low normal load due to the competition between the enhanced interfacial thermal conductance across the contact region and the reduced internal thermal conductance of the silicon ball. The variation of G_eff in the encased silicon ball structure with the external load and diameter has important guidance for the packaging and thermal design of micro/nano-devices.

点接触结构的散热性能在许多微纳器件中至关重要。本研究研究了法向载荷和硅球直径对有效接触热导(G_eff态密度低频声子，导致观察到 G_eff 随着法向载荷的增加而增加。还发现G_eff对硅球直径从2.66到4.16 nm不敏感在低法向负载下，由于接触区域增强的界面热导与硅球内部热导降低之间的竞争。封装硅球结构中的G_eff随外部载荷和直径的变化对封装具有重要指导意义微纳器件热设计。