Preparation And Thermal Conductivity Of Epoxy Composites

With the electronic equipment and lighting equipment development towards miniaturization,large scale integration and high power,integrated circuit working process in electronic equipment will produce more and more heat,and the heat generating part is more concentrated.If the heat can not be passed out in time,it will greatly reduce the efficiency and life of equipment,even failure.Epoxy resin was used as insulating packaging material for electronic devices.However,the thermal conductivity at room temperature is very low,only about 0.1-0.2 Wm-1K-1.And the coefficient thermal expansion is large,result in mismatch with silicon electronic components,which can not guarantee a good cooling effect.Particularly,the high aspect ratio and surface area silicon carbides are provided with excellent properties such as high thermal conductivity,high thermal stability,high breakdown field,excellent mechanical properties and chemical inertness.Thus,using new materials like SiC nanowires(SiC NWs)exhibiting outstanding physical properties,it should be possible to obtain novel electronic packaging composites with extraordinary high thermal conductivity and low CTE mismatch with silicon.Herein,we proposed a rapid and simple strategy for the preparation of epoxy/SiC NWs composites.Based on this method,the SiC NWs in the epoxy matrix results in not only enhanced thermal properties but also great thermal stability performance.Furthermore,core-shell SiC@SiO2 NWs with heating treatment were used to fabricate epoxy/SiC@SiO2 NWs composites.The shell of SiO2 between nanowires,and nanowires with epoxy matrix can bring in low thermal interface resistance and low phonon mismatch.Which leads to high thermal conductivity values and thermal stability of epoxy/SiC@SiO2 NWs composites.The idea of core-shell SiC@SiO2 NWs inspire us to fabricate core-shell structure of CF@G with a simple method of vacuum filtration.The fabricated Epoxy/CF@G composites with great high thermal conductivity and thermo-mechanical property.The epoxy composites are characterized with LFA,IR,DSC and TG for thermal conductivity and thermal stability.(1)The thermal conductivity of epoxy/SiC NWs composite with 3.0 wt%filler addition reached 0.449 Wm-1K-1,approximately a 106%enhancement comparing with neat epoxy.Meanwhile,thermal stability is better than that of similar literature.(2)The unique structure of SiC@SiO2 NWs with interfacial compatibility as fillers bring into neat epoxy.Which the thermal conductivity is significantly increased 79.4%,reached to 0.391 W·m-1K-1,with a 2.5 wt%loading.Higher than the same loading of epoxy/SiC NWs composite.(3)Use of the preparation of core-shell structure CF@G show that the maximum thermal conductivity of fabricated Epoxy/CF@G composites reaches 1.19 Wm-1K-1.Meanwhile,the storage modulus also enhanced by an order of magnitude.The results supply a novel method on enhancement of thermal conductivity of epoxy composites which meet the requirement for the rapid development of the electronic devices,which used in high frequency,high temperature,high current density and corrosion environment.