Study On Preparation And Properties Of Nanoscale Polymer-based Thermal Conductive Composites

With the advent of 5G era,the new generation of electronic components are becoming more and more integrated and miniaturized,resulting in higher demand on packaging materials,causing a sharp increase of heat flux within electronic components,and the heat dissipation problem becomes the bottleneck in the design of the new generation electronic packaging system.Therefore,to ensure the stability of electronic components,we have higher standards for the performance of electronic packaging materials.The thermal conductivity of polymer-based polymer materials is not high(⁰.2 Wm^-1k^-1),which cannot meet the heat dissipation requirements of electronic equipment.Hence it is necessary to add the high thermal conductivity filler to polymer base polymer to improve thermal performance.However,adding large quantities of thermal conductivity fillers will lead to the deterioration of mechanical properties of the material,the reduction in flow,and higher cost.To this end,this paper focuses on polymer composites based on nanometer thermal conductive fillers at low filling volume.We have filled poly?methyl methacrylate??PMMA?and epoxy resin with nanometer carbon series fillers?functionalized go?rGO?multi-wall carbon nanotubes?MWCNT??or nanometer ceramic fillers?h-BNNS-PGMA?,respectively,and successfully created BN/SiO₂-PMMA,PMMA/rGO-AgNPs,PMMA@xMWCNT/yBN andEP/h-BN-PGMA composite thermal conductive materials,etc.In our study,we discover that in the field of thermal insulation and conduction,two kinds of nanoscale thermal conductive filler,namely,Ceramic?BNNS?and carbon filler?MWCNT,GO?have a broad development prospect in the new generation of electronic packaging field.?1?BN/SiO₂-PMMA composites were prepared by solution mixing and high temperature compressing.When only 40 wt%BNNS is added,the thermal conductivity of the composite material is up to 1.198 wm^-1k^-1,599%higher than that of pure PMMA.This is due to the thermal conductivity path formed by BNNS in PMMA matrix.?2?PMMA/rGO-AgNPs were obtained by solution mixing and high temperature compressing.By adding only mixed fillers?rGO+AgNPs:2.5 vol%+2.5 vol%?,the thermal conductivity of PMMA/2.5rGO-2.5AgNPs composites reached 0.54 Wm^-1k^-1,about 2.38 times that of pure PMMA materials.?3?In this paper,PMMA@MWCNT/BN composite material with effective electromagnetic interference and good insulation performance is designed by constructing a double isolation network--thermal conduction and insulation network.PMMA@MWCNT composite microspheres are prepared as conductive microgrids,and BN microgrids are further prepared in the outer layer of the conductive microgrids,which are used for electrical insulation and further improving thermal conductivity.When the packing content is 6 wt%MWCNT and 20wt%BN respectively,the thermal conductivity of 1.098 Wm^-1K^-1,the electronic insulation coefficient of 6.32×10^-7 S cm^-1,and the electromagnetic shielding constant of 14.39 dB at 8.2GHz are achieved.?4?The PGMA polymer was linked to the surface of h-BN,and 4,10 and 16 vol%of h-BN-PGMA was added into the blend epoxy resin EP?E51+CER170?by solution mixing and thermal curing,and the thermal conductivity was increased by 160%,298%or 599%,respectively.The surface grafting of h-BN aims to form a long polymer chain and interconnect each thermal conduction network of h-BN,which is beneficial to enhance the compatibility between BNNS and EP matrix.Compared with EP/h-BN composites,EP/h-BN-PGMA composites have higher thermal conductivity(1.197 wm^-1k^-1)with the same filling volumn?16vol%?.In addition,the excellent dielectric properties and thermal stability show that EP/h-BN-PGMA composite is a good thermal interface material?TIMs?,which can be applied to the field of thermal management.