Abstract
Ba~0.6~Sr~0.4~TiO~3~ (BST) thick films were fabricated on Al~2~O~3~ substrate via the screen printing technology by using B~2~O~3~βLi~2~O additions as liquidβphase sintering aids. The effects of doping of B~2~O~3~ and Li~2~CO~3~ on the phase compositions, microstructures, and dielectric tunable properties of the thick films were investigated systematically. The Xβray diffraction patterns showed that BST diffraction peaks shifted toward higher angle with the B~2~O~3~βLi~2~O doping content, which indicated the substitution of B^3+^ and Li^+^ in Ba^2+^ site. It was also found that the grain size and electrical properties of the thick film were strongly affected by the glass content. The grain size and the relative permittivity decreased obviously with the increase of B~2~O~3~βLi~2~O additive. In addition, for the thick film with 4.5βwt% glass content, optimized sintering, and electrical properties were obtained: the sintering temperature of 900βΒ°C, relative permittivity of 312 (at 10βkHz), dielectric loss of 0.0039, tunability of 16.2% (at 3βkV/mm). These good sintering and electrical properties indicate that BST thick film with B~2~O~3~βLi~2~O addition is benefit for the development of LTCC technology and tunable devices.