An Al@Al2O3@SiO2/polyimide composite with multilayer coating structure fillers based on self-passivated aluminum cores

Abstract

We demonstrate a capability in combining two kinds of nanosize and microsize particles of core-shell Al@Al2O3@SiO2 with aluminum cores to form multilayer coating structures as fillers in polyimide matrix for electronic applications. The core-shell Al@Al2O3@SiO2 structure can effectively adjust the relative permittivity (about 12 @1 MHz) of the composite while keeping lower dielectric loss (0.015 @1 MHz) compared to that uncoated aluminum particles. The combination of “macro” and “micro” coating can significantly improve the dielectric properties of the composites. This work provides a useful method to modify the fillers for polymer matrix nanocomposite materials.

Enhanced thermal conductivity and dielectric properties of Al/β-SiCw/PVDF composites

“…Recently, the surface self-passivated micro or nanometer aluminum particles (Al) was chosen to fabricate the core-shell structured Al (Al@Al 2 O 3 )/polymer composites with an improved thermal conductivity and relatively high permittivity but low dielectric loss [2,17,23,[31][32][33][34]. However, there is much room for improvement in the dielectric constant and thermal conductivity of the composites.…”

“…Recently, the conductor-insulator core-shell structured particle has been employed to prepare polymeric composites with high dielectric constant and low loss. The metal core is used to increase the dielectric constant due to the interfacial polarization (namely, MWS effect), and the insulator shell serves as a barrier layer to control the dielectric loss efficiently through blocking the electron transfer between adjacent metal cores [2,17,23,[31][32][33][34]. Additionally, it is essentially crucial for the heat generated from electronics to be dissipated as quickly and effectively as possible, to maintain the operating temperatures of the electronic equipment at a desired level because the dielectric strength will decrease with increasing temperature owing to a poor thermal conduction of these dielectric materials [35,36].…”

High-performance epoxy/silica coated silver nanowire composites as underfill material for electronic packaging

“…Increasing the loading of AgNWs and AgNWs@SiO 2 also increases the dielectric constant of these composites. Further, epoxy/ AgNWs@SiO 2 composites show lower dielectric constants than epoxy/AgNWs composites with the same filler loading owing to the low relative permittivity of the silica layer [46]. Fig.…”

Novel organic–inorganic composites with high thermal conductivity for electronic packaging applications: A key issue review

“…As the bulk properties of composite materials strictly depend on the structure formed during the processing step , there are many synthesis methods for composite material preparation, and they include mixing oxides method , solution mixing, melt blending, and in situ polymerization. Detailed information may be found in the reviews on this topic .…”

“… (a) Schematic illustration of the combination of “macro” and “micro” coating and (b) schematic illustration of the formation process of the double‐shelled core–shell Al@Al 2 O 3 @SiO 2 particles . [Color figure can be viewed at http://wileyonlinelibrary.com]…”