The Effect of Phonon and Electron on Thermal Characteristics of Cu/Al Interface

The thermal performance of Cu/Al interface structure is studied based on the investigation of the diffusion interfacial thickness, phonon scattering and phonon coincidence degree by using the NEMD (non-equilibrium molecular dynamics) method under different temperatures. There is an interesting phenomenon that the thermal conductivity increases with the increasing temperature although the phonon scattering becomes more seriously which would reduce the thermal conductivity of Cu/Al interface. It implies that the phonon is not the only factor affecting the thermal conductivity. Then, the MD-TTM (molecular dynamics-two temperature model) mixed model is used to describe the interfacial heat transfer considering the coupling of phonon and electron. The results show that the electron affects the thermal performance of the Cu/Al interface and it becomes more and more intense with the increase of temperature, which proves that the phonon is not the only thermal transfer carrier in the metallic interface. The investigation is helpful for understanding the heat transfer mechanism in the metallic matching interface, which implies a potential method for the analysis of the interface performance and the design of the interface in micro/nano manufacturing.