Study On Preparation And Modification Of Epoxy-based Thermally Conductive Composites

Due to the increasing demand for miniaturization and integration of electronic components in the electronics industry,thermal management of electronic devices has become a problem that cannot be ignored.Epoxy resin has the characteristics of low price,good processing performance,and good adhesion to the substrate,which makes it have great advantages compared to other packaging materials.Therefore,the epoxy resin-based composite material with high thermal conductivity is prepared.Very necessary.In this project,epoxy resin was used as the matrix,and a variety of fillers were added to prepare a highly thermally conductive epoxy-based composite material.The impact is studied by XRD,scanning electron microscope,thermal conductivity analyzer,vibration sample magnetometer,etc.The changes of microstructure,thermal conductivity,dielectric properties,electrical conductivity and magnetic properties of composite materials were discussed,and ways to improve their thermal conductivity were discussed.First,the effects of filled silica,aluminum nitride,and hexagonal boron nitride on the thermal conductivity of composites at high filling contents were investigated.A composite film with high filling content was prepared by the casting method.It was found that among the three composite materials,the higher the thermal conductivity of the filler,the higher the thermal conductivity of the prepared composite material.The matrix brought defects,which reduced the density of the composite material,which caused the overall dielectric properties of the composite material to be deteriorated.In view of various properties,the composites filled with Al N had the least influence on the epoxy resin matrix,but also have high thermal conductivityThen,the composites filled with a small aspect of the high-aspect ratio conductive phase(flake graphite,multi-walled carbon nanotubes and nickel-plated multi-walled carbon nanotubes)in the system with a low filling content were prepared.The synergy between these fillers and the characteristics of high aspect ratio materials are more likely to conduct heat,and the thermal conductivity of the composite was improved while sacrificing the processing performance of the composite as little as possible.SEM images showed that multi-walled carbon nanotubes have agglomerated more in the composite material,which deteriorates the dielectric properties of the composite material and suppresses the improvement of the material's thermal conductivity.When filled with nickel-plated multiwalled carbon nanotubes,the agglomeration phenomenon was significantly reduced.With the increase of the filler content,due to the characteristics of the one-dimensional material made it have a higher aspect ratio than the flake graphite,so it has three kinds when the filling content is 2vol.%.Highest thermal conductivity in composites.Finally,the effects of nickel powders with different particle sizes on the thermal conductivity of composites under different magnetic field conditions were studied.Studies have shown that 50 nm nickel powder has agglomeration in epoxy resin with or without magnetic field induction,so the thermal conductivity is the lowest under any circumstances,and without magnetic field induction,the composite material filled with the 10?m nickel powder has a higher thermal conductivity,and the composite material filled with 1 ?m nickel powder has a higher thermal conductivity under the induction of a magnetic field in the same direction as the thermal conductivity.These laws was verified by simulation modeling.