Silver/polymer nanocomposite as a high-k polymer matrix for dielectric composites with improved dielectric performance

A silver (Ag)-polymer nanocomposite has been developed by in-situ formation of metal nanoparticles within the polymer matrix and utilized as a high-dielectric constant (k) polymer matrix to enhance the dielectric properties of high-k composite materials. By using an in-situ photochemical reduction method, uniformly dispersed Ag nanoparticles of size of around 10 nm were generated in polymer matrices. Self-passivated aluminium (A1) particles were incorporated into this Ag-epoxy matrix and the dielectric properties of the as-prepared composite materials were investigated. The composites showed more than 50% increase in k values as compared with an A1/neat epoxy composite with the same filler loading of A1. The dielectric loss tangent of the A1/Ag-epoxy composites was below 0.1, which meets the requirement for embedded decoupling capacitors. These results suggest that the Ag-epoxy high-k polymer matrix effectively enhances the dielectric constant while maintaining the low dielectric loss of the high-k composites. In addition, detailed dielectric property measurements revealed that the dielectric properties and their frequency dispersion as well as the breakdown behaviors of the A1/Ag-epoxy composites were related to the incorporation and concentration of Ag nanoparticles in the high-k polymer matrix.