Research On Interfacial Thermal Transport Properties Of Carbon Matrix Composite For Thermal Management

The integration level and power consumption of chips increase rapdily with the semiconductor industry,which lead to a challenge in heat management of chips.And the complex chip structure even makes it harder to effectively dissipate those heat.The most important parts of chip thermal management is packaging.It is the heterogeneous interface in the composite material that affects the thermal conductivity of the composite packaging material.In this paper,molecular dynamics simulations are used to investigate the thermal transport properties of the third-generation electronic chip packaging materials,metal-based carbon materials.Firstly,the thermal conductivity of the copper/diamond system is calculated,and it is found that copper and diamond have different hot carriers and phonon density of states,which limit the thermal transport at the interface.By calculating the phonon density of states of the two materials at the interface,adding cavity defects to the nanoscale diamond layer near the interface is employed to improve the interface phonon coupling.The calculation results show that when the defect concentration is 8 %,the interfacial thermal conductivity of copper and diamond is improved by 89.2% compared with the initial one.It is further found that although the thermal conductivity of the defective diamond thin layer has decreased,it is still much higher than that of the general thermal interface material,so the total thermal resistance at the interface is still greatly reduced.The thermal conductivity of copper/graphene interface was calculated,and it was found that the main factor affecting the thermal conductivity of the interface was the out-of-plane thermal transport properties of graphene.The interfacial thermal transport properties of multilayer graphene mainly depend on its interlayer forces,and adding cavity defects has little effect on improving the interfacial thermal conductivity.Since single-layer graphene have no other graphene layers to affect,its out-of-plane thermal conductivity are better than those of multilayer graphene.Adding defects can increase its interfacial thermal conductivity by 20%.The thermal conductivity of the nickel/multilayer graphene interface system was calculated,and it was found that the interfacial thermal transport also depends on the out-of-plane thermal transport properties of graphene.Similar to the copper/diamond and copper/graphene interface systems,the phonon density of states overlap of the interfacial materials is one of the main factors affecting the thermal transport at the heterointerface.In this paper,the thermal transport properties of metal-carbon material composites,especially the interfacial thermal transport properties,were investigated by molecular dynamics.The thermal transport properties between high thermal conductivity carbon materials such as diamond,graphene and conventional metals are analyzed.The vacancy defects are innovatively proposed the to improve their interfacial thermal conductance.It is clarified that the main influencing factor that dominates the thermal transport at the heterointerface is the contact ratio of the phonon density of states of the two materials.The conclusions of this paper are helpful for the development and application of next-generation metal-based carbon materials.