Enhanced Thermal Conductivity of Epoxy Adhesive Films by Filling Surface-Modified AlN

With the development of electronic components towards miniaturization, thinning, and high performance, effective heat dissipation is crucial to the performance of high-power electronic products. Thermal management of electronic packaging materials thus becomes important. Aluminum nitride (AlN) particles have attracted extensive attention owing to excellent thermal conductivity and insulation properties. In this work, AlN particles are firstly hydrolyzed to render a layer of Al(OH)3 on the surface of AlN to form AlOOH@AlN. Then, 3,5-diaminobenzoic acid (DABA) is reacted with the -OH moieties on AlOOH@AlN surface to form surface-modified AlN (i.e., DABA-AlOOH@AlN). The surface -NH groups of DABA-AlOOH@AlN can react with the epoxy and improve the dispersion of AlN fillers in epoxy matrix. When the filler content is 60 wt.%, the thermal conductivity of DABA-AlOOH@AlN/Epoxy composite film is 0.97 W/(m•K), 23% higher than that of epoxy composite film filled with unmodified AlN. Moreover, coefficient of thermal expansion (CTE) of the DABA-AlOOH@AlN/Epoxy is 10% lower than that of AlN/Epoxy films. Such composite materials may find potentials in fabrication of high-performance thermal conductive films for electronic packaging.