As an excellent two-dimensional insulating material with high thermal conductivity , high temperature stability and high hardness, hexagonal boron nitride(h-BN) is widely applied in semiconductor manufacturing, aerospace, metallurgical manufacturing and other cutting-edge fields. However, the unique surface structure of h-BN leads to poor lubricity and easy agglomeration, which limits the application of h-BN especially in the field of electronic packaging. To address key issues boosted above, this study designed and prepared the BN@Fe 3 O 4 magnetic insulating particles and doped it into the reduced viscosity epoxy resin to prepare the composites. By selecting appropriate external magnetic field strength and BN@Fe 3 O 4 particles’ content, a novel 3D structure of fillers like dominoes in epoxy resin composite was successfully constructed. The microstructure of the BN@Fe 3 O 4 particles and composites were analyzed, the thermal conductivity, the mechanical and the electrical properties of composites were simultaneously tested. Results manifested that the core-shell structures with BN as core and Fe 3 O 4 as shell was successfully prepared, linking through the PDA middle layer between the BN core and Fe 3 O 4 shell. Under the influence of magnetic orientation, the BN@Fe 3 O 4 magnetic particles were preferred an out-of-plane oriented in the epoxy resin composites, resulted an enormously enhanced on thermal conductivity of composites. At a magnetic field strength of 60 mT and 25 vol% BN@Fe 3 O 4 content, the thermal conductivity of BN@Fe 3 O 4 /EP composites is as lofty as 1.832 W/(m K), which is 1023.46% higher than that of pure epoxy resin. Meanwhile, the thermal stability has also been slightly improved, the elastic modulus and insulation performances remain at the same level.
Epoxy resin (EP), as a resin material with excellent insulation performance, has been widely applied in fields such as electronics, coatings, ships etc. However, epoxy resins generally have poor thermal conductivity, which limits their application in the field of new generation of electronic packaging. To address the key issues mentioned above, the BN@Fe 3 O 4 particles with positive out-of-plane thermal conductivity were successfully prepared in this study, having a core-shell structure with rough surfaces as well. As a thermal conductive powder, the disadvantage of hexagonal boron nitride being easily agglomerated in resin has been improved. By applying an external magnetic field, three-dimensional thermal conduction pathways were constructed in the matrix. The physical and chemical properties of the BN@Fe 3 O 4 powder and its composite materials were analysed and tested. The experiment indicates that the thermal conductive magnetic powder BN@Fe 3 O 4 had been successfully prepared. When the filling amount of BN@Fe 3 O 4 reached 27.5 vol%, the out-of-plane thermal conductivity of the composite material was 1.758 W m −1 K −1 , which was 982.12% that of pure EP. At this point, the mechanical behaviour and insulation performance of EP composite materials can be effectively guaranteed at the same order of magnitude as pure EP performance.
Zeyu You,Ling Weng,Zijian Wu,Xiaorui Zhang,Yongliang Wang
As an emerging field of current technological development, the heat dissipation performance of electronic packaging materials has become the key to determining product reliability. Therefore, the applied thermal interface materials (TIMs) need to simultaneously meet the performance indicators of thermal conductivity, mechanics, and insulation. Although BN had excellent in-plane thermal conductivity and insulation performance, it is currently difficult to achieve vertical orientation of powder which leads the layered powder cannot complete a continuous and effective heat transfer path along the Z -axis direction inside the composite material. In order to solve the above two problems, out-of-plane thermal conductive composite was prepared by introducing magnetic oriented method. In order to comprehensively evaluate the thermal conductivity, mechanical and electrical properties, BN@Fe 3 O 4 /EP magnetic oriented composites were compared with BN@PDA-Al 2 O 3 /EP composite prepared by mechanical blending method. The vertical thermal conductivity of the magnetic oriented composite material was 2.24 W/(m·K) at 30 vol%, which was 3.39 times that of the blended composite material and 12.4 times that of pure EP. This proves that the magnetic oriented composite materials prepared by the research institute can meet the vertical heat transfer needs in the field of electronic packaging and have high research value in this area. Highlights BN@Fe 3 O 4 core–shell particles were prepared with both thermal conductivity and magnetic controllability. The thermosetting composites were prepared by heated through preliminary gel point and then cured at high temperature. The orientation of powder inside the matrix was constructed, resulted in excellent out-of-plane heat transfer performance. Comparisons were made between various properties of magnetic oriented materials and conventional blend materials. The magnetic orientation method is feasible in the field of electronic packaging.
危险品化学品经营许可证（带存储）