Thermal Conductivity Of Graphene/Epoxy Electronic Packaging Composites

After the epoxy resin and curing agent are cured,many excellent properties can be obtained,and they are widely used in various industrial applications such as coatings,adhesives and encapsulation.However,the thermal conductivity of epoxy resin is not high,which limits its development in the field of electronic packaging,and the researches of epoxy resin are generally based on experimental characterization,which cannot be studied at the microscopic molecular level.Molecular simulation methods can conduct mechanism research from the micro level,but the use of molecular simulation methods to study its modification mechanism is quite scarce.In this thesis,graphene and graphene oxide were used as admixtures,and 4,4'-Diaminodiphenylsulfone(DDS)was used as curing agent.Built the system models of epoxy resin,graphene/epoxy resin,graphene oxide/epoxy resin,and the epoxy resin composite material without admixture was used as the control group.Molecular dynamics research and first-principles calculations were carried out on the three composite systems to illustrate the distribution state of composite materials and clarify the composite mechanism of graphene,graphene oxide and epoxy resin.Then three composite materials of epoxy resin,graphene/epoxy resin and graphene oxide/epoxy resin were prepared,and the thermal conductivity of the composite materials was measured.The results of the study are as follows:Molecular dynamics studies show that when graphene and graphene oxide are used as admixtures,curing agent molecules will gather around graphene and graphene oxide.As the temperature rises,the distance of the curing agent molecules gathering around graphene and graphene oxide will increase,thereby affecting the curing reaction of the epoxy resin and the curing agent.Among them,the influence of graphene oxide on epoxy resin composite material is larger than that of graphene.First-principles calculations show that adding graphene or graphene oxide to the epoxy resin will release more energy than the epoxy control system,which helps to improve the stability of the system.Moreover,the interaction between graphene oxide and epoxy resin is strong,and the formed system is the most stable.Thermal conductivity experiments show that graphene and graphene oxide as admixtures can improve the thermal conductivity of epoxy resin.Excluding the difference in the thermal conductivity of graphene and graphene oxide itself,the effect of graphene oxide on the thermal conductivity of epoxy resin is stronger than that of graphene.This result confirms the results of molecular dynamics and first-principles calculations.Graphene oxide is rich in oxygen-containing groups,which helps the interaction between graphene oxide and epoxy resin.Therefore,graphene oxide and epoxy resin can form the better thermal conductivity network,and the thermal conductivity of composite materials can be improved more significantly.The research of this subject is to study the distribution state and interface bonding mechanism of the epoxy resin composite material from the micro-molecular level through simulation calculation.It not only provides the theoretical basis for the design of graphene/epoxy resin electronic packaging composite materials,but also provides research ideas and methods for the development of new epoxy resin electronic packaging composite materials.