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

Core-shell structured SiO 2 particles were added to polyolefin matrix to prepare copper clad laminates (CCLs) with high thermal conductivity, low dielectric loss ( D f ) and low dielectric constant ( D k ) for the 5G age. In this work, core-shell structured SiO 2 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@SiO 2 , achieved D k  = 3.57 and D f  = 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 SiO 2 particles have a potential for use in high-frequency printed circuit boards (PCBs).