Study On The Construction And Thermal Conductivity Of Thermal Interface Material With Different Dimensions Of Carbon Materials

With the advancement of technology,microelectronics(semiconductor)and other devices have the trend to become smaller,the power density of circuit boards is increasing,and the heat generation of single power device and integrated circuits and the entire electronic system are increasing dramatically.However,the reliability of the operation of electronic equipments will be greatly reduced as the temperature increases,and the service life will be affected to some extent.Therefore,it is very important for a electronic equipment to maintain its stable operation temperature in its suitable range and prolong the service life of electronic equipment.Therefore,the preparation of a low-cost,high-thermal-conductivity thermal interface material(TIM)is necessary to solve the heat dissipation problem in electronic equipment.If grease is used as the matrix,carbon nanotubes(Carbon Nanotubes,CNTs,1D),Graphene Nanoplatelet(GNP,2D),and three-dimensional graphene(3D)and other carbon materials with different dimensions are used as thermal fillers separately,their respective thermal conductivity cannot be fully utilized.In this paper,dimethyl silicone oil is used as a matrix,and each two of the three carbon materials of different dimensions are compounded as a thermal conductive filler.In this way,the synergistic effect of carbon materials of different dimensions is used to improve the thermal conductivity of thermal grease thermal interface materials.The main contents are as follows:The dimethicone is used as the base oil,and carbon nanotubes,graphene,or carbon nanotube / graphene composite materials were used as the thermally conductive fillers to prepare thermally conductive silicone grease,and its thermal conductivity is measured.With carbon nanotubes as the single thermally conductive filler,when the amount and length of carbon nanotubes are the same,the smaller the diameter of the carbon nanotubes,the more obvious the thermal conductivity of the thermally conductive silicone grease is increased;When the amount of carbon nanotubes addition is the same as the diameter of the tube,the length of the carbon nanotubes is within the effective length range,long carbon nanotubes are more conducive to the improvement of thermal conductivity of thermally conductive silicone grease.When carbon nanotubes and graphene nanosheets are used as composite thermally conductive fillers,the length advantage of carbon nanotubes is not exerted.When the tube diameter is the same,short carbon nanotubes are more conducive to improving the thermal conductivity of thermally conductive silicone grease.When the tube length is the same,the smaller the diameter of the carbon nanotube tube,the higher the thermal conductivity of the thermally conductive silicone grease.In addition,when the carbon nanotube / graphene hybrid filler accounts for 6% of the total filler amount,and the carbon nanotube and graphene ratio is 3: 1,the thermal conductivity of the thermally conductive silicone grease increases by21%.Carbon nanotubes play a role in separating and bridging graphene nanosheets,improving the dispersibility of graphene nanosheets,facilitating the formation of a three-dimensional heat conduction network,and thereby improving the thermal conductivity of thermally conductive silicone grease.We used dimethyl silicone oil as the base oil and carbon nanotube / three-dimensional graphene composite carbon material as the thermally conductive filler to prepare thermally conductive silicone grease and measure its thermal conductivity.As the filler content of thermally conductive fillers continues to increase,the thermal conductivity of thermally conductive silicone greases will increase.The effect of dispersant Tween on the thermal conductivity of silicone greases is related to the fluidity of silicone greases.With the increase in the amount of Tween,the thermal conductivity of the silicone grease with strong fluidity improves significantly,and then the improvement effect gradually weakens.With the increase in the amount of Tween,the silicone fluid with poor fluidity first has a small improvement in the thermal conductivity of the silicone grease,and then the improvement effect is gradually obvious.In the preparation of the thermally conductive silicone grease system where CNTs /three-dimensional graphene composite carbon material is the thermally conductive filler,CNTs play a role in separating and bridging three-dimensional graphene.Short and thin CNTs are more conducive to the formation of three-dimensional heat conduction networks,which can further improve the thermal conductivity of thermal grease.When the total amount of thermally conductive filler is 6 wt%,the thermal conductivity of thermally conductive silicone grease under CNTs / three-dimensional graphene composite carbon filler can be improved by nearly 26%.We use dimethyl silicone oil as the base oil,and graphene nanosheets(GNP)/three-dimensional graphene composite carbon materials as thermal conductive fillers to prepare thermal grease.When GNP is used as a single thermally conductive filler,as the amount of GNP filler increases,the thermal conductivity of thermally conductive silicone grease will also increase.With the same number of layers,a small GNP will help improve the thermal conductivity of thermally conductive silicone grease.In thermally conductive silicone grease systems where the CNTs / three-dimensional graphene composite carbon material filler is a thermally conductive filler,GNP plays a role in separating and bridging three-dimensional graphene.Small-sized GNPs are more conducive to the formation of three-dimensional heat conduction networks,which can improve the thermal conductivity of thermal grease.GNPs beyond a certain size range even have a negative effect on the thermal conductivity of silicone grease.When the GNP / three-dimensional graphene composite is a thermally conductive filler and the total amount of thermally conductive filler is 6 wt%,the thermal conductivity of the thermally conductive silicone grease can be increased by 24%.The influence of Tween on the thermal conductivity of silicone grease is related to the fluidity of the silicone grease.As the amount of Tween increases,the thermal performance of the silicone grease with high fluidity increases significantly,and then the improvement effect gradually decreases.With the increase of the amount of Tween,the thermal performance of the silicone grease with poor fluidity are not improved very much first,and then the improvement effect is gradually obvious.