National Chiao Tung University professor / STSP Wang Hong Xi TF: Magical fertilizer, building 3D boron foam filled epoxy composites efficient thermal management

As electronic devices continue to miniaturization, integrated and multi-functional direction, the power density is increased, the amount of heat per unit volume is growing. Heat generated when the work of electronic components, electronic components is a key factor affecting performance and service life, heat dissipation has become a bottleneck restricting the development of microelectronic devices and systems and applications. Especially with the rapid layout 5G and autopilot technology, thermal management materials has raised new challenges. 5G substrate material for the base station and the autopilot radar requires both high thermal conductivity, low dielectric constant and dielectric loss. Traditional randomly dispersed by the addition of thermally conductive filler to the polymer matrix of the method was not effective in increasing thermal conductivity, but also greatly increase the dielectric constant and dielectric loss of the composite material. For the above problems, Professor Wang Hong TF NH4HCO3 employed as a sacrificial material, proposes a simple and general method to construct a three-dimensional foam boron (3D-BN), and then by 3D-BN-filled epoxy composite material is obtained. The method of using the composite material is not only simple, and can greatly improve the thermal conductivity of the composite material. Longitudinal thermal conductivity of the composite material prepared in up to 6.11 W m ^-1 K ^-1 . Research carried out by the finite element method analysis further showed that, due to the high thermal conductivity foam 3D-BN, BN foam wherein only sheet-like boron nitride, boron nitride and boron nitride under a pressure tight connection, which compound materials capable of providing rapid phonon transport path. The composite material also has excellent insulating properties, low dielectric constant and dielectric loss. The method of packing generally increases the thermal conductivity of polymeric materials having high thermal conductivity is added to the polymer matrix composites were prepared thermally conductive encapsulating material. However, due to high interfacial thermal resistance between the polymer matrix and a thermally conductive filler, a simple filled and can not effectively increase the thermal conductivity of the composite material. In this case, only continue to improve the thermal conductivity of the volume fraction of the filler in order to obtain desirable, but too high will increase the dielectric constant of the filler to the composite material, the deterioration of the mechanical properties of the material. In the present study, by selection and regulation of the thermally conductive filler material BN and pyrolytic particle size of the two solid NH4HCO3Effective to construct a three-dimensional network skeleton, and when more than 8 times and at least two significantly different size material during the mixing process can be achieved efficiently mounting structure, the thermally conductive filler and small particle size fumed thermally conductive filler material large particles are adsorbed on the particle surface surrounding the pyrolyzed material, so that, during the pressing process, the pressure will be focused to a smaller-diameter thermally conductive fillers, the thermally conductive filler between a three-dimensional framework can be enhanced by pressing contact with each other, further reducing the interface resistance between the filler, such heating may further decompose NH4HCO3, whereby the boron nitride foam which is capable of providing effective phonon transmission channel of the three-dimensional structure of the composite material was filled epoxy. Meanwhile, the work also using the finite element simulation depth analysis of the growth mechanism of thermal conductivity, provides a new theoretical basis for effectively improve the thermal conductivity. The authors found that the thermally conductive filler, and various random padding, when three-dimensional network thermally conductive filler, the thermal conductivity of the composite will rise with the thermal conductivity of the thermally conductive filler increases linearly. When the random padding, when the thermal conductivity of the thermally conductive filler is increased to some extent, simply by upgrading the thermal conductivity of the filler does not significantly improve the thermal conductivity of the composite material. The research work \”3D boron nitride foam filled epoxy composites with significantly enhanced thermal conductivity by a facial and scalable approach\” was published top journals in the international field of chemical engineering Chemical Engineering Journal [ 123] (the real-time impact factor 10.83), the first author of the work for the Institute of Microelectronics, Xi\’an Jiaotong University doctoral Xu Xin did not , corresponding author for the South University of Technology Professor of Wang Hong . Xi\’an Jiaotong University as the first unit, the South University of Technology and Pennsylvania State University in cooperation with the United States for this article. This work was supported by the Shenzhen Municipal Science and Technology Program (peacock team and Basic Research Program), support of the Shenzhen Municipal Engineering Laboratory project. Papers link: https: //www.sciencedirecHe .com / science / article / P II / S138589472031439X? Via% 3DI hub