Preparation And Properties Of Al N@Al₂O₃/EP Thermal Conductive Composites

With the increasing miniaturization and integration of electronic components,they will generate a large amount of thermal energy during the daily work and accumulate on smaller device units,resulting in excessive local temperature and increased internal stress,which will seriously affect the use accuracy of electrical appliances and service life.Therefore,how to effectively manage the heat generated by the components has become an increasingly urgent issue in the development of electronic and electrical integration technology.In this paper using AlN and AlN@Al₂O₃as thermally conductive fillers,epoxy resin as the matrix,and MNA as the curing agent to prepare two thermally conductive composite materials.Firstly,AlN@Al₂O₃thermally conductive filler with core-shell structure was prepared by utilizing the characteristics of AlN which is prone to hydrolysis.KH560 was then used to modify the two thermally conductive fillers to increase their surface activity,so that they could be uniformly dispersed in the epoxy resin system.Finally,the thermally conductive filler is introduced into the epoxy resin system and cured to prepare a thermally conductive composite sample.The situation before and after the modification of two kinds of thermally conductive particles is characterized vis SEM,EDS,XRD,TGA,DSC,dielectric analyzer,electronic universal testing machine and other analysis and testing technology.Then the onlooking mechanism of the thermally conductive composite material and analyze its performance are analyzed.The results showed that AlN@Al?OH?₃was successfully prepared by hydrolysis,and it was verified that the product after high temperature sintering was indeed AlN@Al₂O₃with core-shell structure.KH560 was used to perform silane coupling treatment on AlN and AlN@Al₂O₃.Tests showed that KH560molecules were successfully grafted on the surface of both thermally conductive particles,and the modification effect was very obvious.The dispersion was significantly improved in the epoxy resin system,conducive to the improvement of thermal properties of composite materials.Adding 50 wt%AlN@Al₂O₃to the epoxy resin system,the resulting AlN@Al₂O₃/epoxy resin composite material has the best thermal conductivity,the thermal conductivity of the composite material is 1.89 W/?m·K?,which is 1012%higher than that of the pristine epoxy resin.The composites maintain good thermal conductivity over a long period of use.The introduction of AlN@Al₂O₃can improve the thermal stability,thermal decomposition temperature and glass transition temperature of the composites.When the content of AlN@Al₂O₃is 50 wt%,the glass transition temperature of the composite is 147.74?,and the decomposition temperature of the composite in 10 wt%mass loss is 398.88?.Then the mechanical and electrical properties of the material can meet the requirements for the use of electrical packaging materials.