Study On The Preparation And Performance Of Epoxy Resin/SiC Composites

The large amount of heat generated inside will affect the stability and operational life of the equipment,and the heat dissipation has become one of the biggest challenges for electronic products.Due to the advantages of corrosion resistance,convenient processing and fatigue resistance,polymers are widely used in microelectronic field.However,the inherent thermal conductivity of the polymer is very low,limiting its application for electronic packaging.It is a very convenient solution to improving its thermal conductivity by adding thermally conductive fillers to the polymer.Compared with the traditional nanofiller,silicon carbide（Si C）has a promising protential in nanocomposites.Ideal new electronic packaging composites would be achieved through combination of Si C and epoxy resin.In this dissertation,to improve the thermal conductivity of epoxy resin,epoxy resin/Si C composites were successfully prepared from two aspects:surface modification and thermal conduction path construction.In addition,the effects of different filler forms（dispersed particle filler and three-dimensional continuous filler network）on the thermal conductivity of composites were compared.At the same time,computer molecular simulation technology is used to verify the feasibility of the experiment,which provides a new idea for the preparation of other high thermal conductivity materials.First,the thermal oxidation of silicon carbide（Si C）was carried out to give a core-shell Si C@Si O₂.Further,the oxidation layer on the surface of Si C was modified.The Si C@Si O₂increases the electron-hole pair transport efficiency of the semiconductor material.In addition,the special core-shell structure and the treatment of silane coupling agents improve the interfacial compatibility between fillers and polymers,and effectively reduce the interfacial thermal resistance（ITR）.The thermal stability,thermomechanical properties and thermal conductivity of the EP/Si C@Si O₂composites were improved.At 25°C,when the filler content of the epoxy resin/Si C@Si O₂composite was 3.4 vol%,the maximum storage modulus was 2150 MPa,and for the epoxy resin without filler,the storage modulus increased by 32.2%.When the total filler content is 17.0 vol%,the thermal conductivity of epoxy resin/Si C@Si O₂composite is up to 0.857 W/（m·K）,which is 328.5%higher than that of pure epoxy resin.Then,a novel three-dimensional Si C（3D-Si C）framework was successfully fabricated using the salt template method,epoxy composites were prepared by infiltration of epoxy liquid into the 3D-Si C followed by a heat-curing process.When the filler content is only13.8 vol%,the thermal conductivity of epoxy resin/3D-Si C composite is 1.032 W/（m·K）,which is 416.0%higher than that of pure epoxy resin.Furthermore,the effects of different filler forms on the thermal conductivity of composites were compared.Composites based on three-dimensional filler networks have obvious advantages in terms of thermal conductivity enhancement rates.The ITR is calculated to be 4.1×10^-8m²·K/W by mathematical model,which is an order of magnitude lower than that of the epoxy composite without the 3D network.Finally,using molecular dynamics simulation technology,the thermal conductivity structure model of pure epoxy resin is constructed,which verifies the feasibility of molecular simulation technology.Then,the epoxy resin/3D-Si C and epoxy resin/Si C@Si O₂models were constructed by molecular simulation technology,and compared with the experimental results and discussed...