Research On Preparation And Performance Of Aluminum Matrix Composites For Electronic Packaging

With the rapid development of the electronic information age,more and more components are carried on the semiconductor,which has caused a sharp increase in the heat generated.Therefore,it is essential to solve the heat dissipation problem of semiconductor devices,and the performance requirements of electronic packaging materials are also more stringent.Traditional electronic packaging materials cannot meet the requirements of semiconductor packaging at this stage due to their low density,low thermal conductivity and high coefficient of thermal expansion.Aluminum-based composite materials have low density,high thermal conductivity and low coefficient of thermal expansion,making them the mainstream materials in electronic packaging materials.In this paper,three aluminum matrix composite materials,Al-Si,Al-Si C,and Al-Diamond,were prepared using a fast hot pressing method with low burning temperature and fast heating rate.By studying the influence of sintering process parameters on the density and microstructure of composite materials,the optimal sintering process parameters are determined.Parameters.The main research content of this thesis is as follows:1.Preparation of Al-Si composite materials by fast hot pressing method.Through the optimization of the sintering process parameters,a fully dense Al-70Si composite material was prepared under the conditions of 470℃,300 MPa,and thermal insulation for 5 min.Through the study on the influence of Si content on the thermal conductivity and coefficient of thermal expansion of Al-Si composite materials,it is found that the thermal conductivity and coefficient of thermal expansion of composite materials both show a downward trend with the increase of Si content.2.Preparation of Al-50Si C composite materials by fast hot pressing method.Through the study of the sintering process parameters,under the sintering process parameters of 510℃,150 MPa,and thermal insulation for 5 min,the density of the prepared composite material is2.95 g/cm³,and its density reaches 99.9%.Si C with two particle sizes of 4μm and 9μm were used to prepare enhancer particles with different particle size-to-mass ratios,and the influence of particle size on the thermal conductivity and coefficient of thermal expansion of composite materials was studied.Studies have shown that with the increase of the mass of large particles of Si C（that is,the increase of the Si C particle size-to-mass ratio）,the thermal conductivity and coefficient of thermal expansion of Al-50Si C composite materials are showing an upward trend.When the Si C particle size-to-mass ratio is 9μm:4μm=3:1,the thermal conductivity of the composite material reaches a maximum value of 165.6 W/m·K,and the coefficient of thermal expansion is 12.51×10^-6K^-1.3.Preparation of Al-Diamond composite materials by fast hot pressing method.Diamond with two particle sizes of 35μm and 55μm is used,and the mass ratio is 55μm:35μm=3:1as the enhancer,and it is formulated with pure aluminum powder into a double particle size Al-50Diamond composite material.The density of the composite material prepared with process parameters of 560℃,80 MPa,and thermal insulation for 10 min reaches 3.19 g/cm³,and the density is as high as 99.7%.The study found that changes in sintering temperature,pressing pressure,and heat preservation time all have a significant impact on the thermal conductivity of the material;the thermal conductivity of the material prepared under the optimized process parameters reaches 527.8 W/m·K.