Improved dielectric and thermal properties of core−shell structured SiO2/polyolefin polymer composites for high-frequency copper clad laminates

Abstract Core-shell structured SiO2 particles were added to polyolefin matrix to prepare copper clad laminates (CCLs) with high thermal conductivity, low dielectric loss (Df) and low dielectric constant (Dk) for the 5G age. In this work, core-shell structured SiO2 particles with different shell thicknesses were fabricated by coating ethylene-propylene-dicyclopentadiene (EPDM) onto their surface. The effect of shell thickness (0, 6, 9 and 13 nm) on the properties of CCLs was investigated. CCLs, with a shell thickness of 13 nm EPDM@SiO2, achieved Dk = 3.57 and Df = 0.0032 at 10 GHz and exhibited stable dielectric properties in a wide frequency range (3 GHz to 18 GHz). The as-obtained CCLs had a thermal conductivity of 0.56 W/(m·K), which is higher than that of the non-coated CCLs [0.46 W/(m·K)]. Moreover, the as-obtained CCLs showed good mechanical properties and solvent resistance. Hence, the as-obtained CCLs with surface rubberised SiO2 particles have a potential for use in high-frequency printed circuit boards (PCBs).