BaTiO3/epoxy composites have been widely investigated as promising materials for embedded capacitors in printed circuit boards. It is generally known that the dielectric constant (K) of the BaTiO3/epoxy composites increases with improvement of the dispersion of BaTiO3 particles in the epoxy matrix that comes from adding surfactant. The influences of surfactant addition on the dielectric properties of the BaTiO3/epoxy composites are reported in the present study. The dielectric constant of the BaTiO3/epoxy composites is not significantly affected by the surfactant addition. However, the temperature coefficient of capacitance increases and the peel strength decreases as the amount of added surfactant increases. The influences of surfactant addition on the dielectric properties of the neat epoxy are also very similar to those of the BaTiO3/epoxy composites. The residual surfactant in the BaTiO3/epoxy composites affects the temperature coefficient of capacitance and the peel strength of the epoxy matrix, which in turn affects the temperature coefficient of capacitance and the peel strength of the BaTiO3/epoxy composites.

BaTiO3/epoxy composites can be applied as the dielectric materials for embedded capacitors. The effects of the degree of BaTiO3 particle agglomeration on the dielectric properties of BaTiO3/epoxy composites were investigated in the present study. The degree of particle agglomeration was controlled by the milling of the agglomerated particles. The size and content of the agglomerated BaTiO3 particles decreased with an increase in the milling time. The dielectric constants and polarizations of BaTiO3/epoxy composites abruptly decreased with the increase of the milling time. It was concluded that the dielectric constants and polarizations of BaTiO3/epoxy composites decreased as the degree of particle agglomeration decreased. The degree of agglomeration of BaTiO3 particles turned out to be a very influential factor on the dielectric properties of BaTiO3/epoxy composites.