Thick Film Capacitors with Variable Tc on Cu Foils

Abstract

ABSTRACTHigh k dielectric thick films, consisting of BaTiO3, a low softening glass and fluoride compounds, were studied to apply them as potential low temperature N2-fireable capacitors on commercially-available Cu foils. Different additive combinations of LiF, ZnF2 and BaF2 were specifically compared in terms of dielectric constant, dielectric loss and Curie temperature (Tc) for the purpose of optimizing dielectric performance. The thick film consisting of 95BaTiO3-1.5LiF-1.5ZnF2-2 bismuth borosilicate glass exhibited the best performance, i.e., a dielectric constant of 2,382 and a dissipation factor of 0.021 at Tc of 27°C at the firing temperature of 950°C. This result can be regarded as one of the best performance, compared to literature reported on embedded capacitors in Cu-PCB applications. No apparent Cu-diffusion was detected across the Cu-thick film-Cu foil structure.