Low Sintering Temperature of CuO-Fluxed Ag(Nb, Ta)O 3 Dielectric Ceramics

Solid solutions in the Ag(Nb x Ta 1−x )O 3 (where 0 ≤ × ≤ 1) system exhibit excellent dielectric properties at microwave frequency including high dielectric constant (200 0.65 Ta 0.35 )O 3 +55wt% Ag(Nb 0.35 Ta 0.65 )O 3 ) yielded an average dielectric constant of 450 and a TCC of 180ppm/°C. Microstructure analysis revealed that a CuO-rich liquid remains at the grain boundary and transmission electron microscopy shows that the CuO resides at triple points. Ag(Nb x Ta 1− x )O 3 ceramics were successfully integrated into LTCC for embedded capacitors. The addition of CuO lowered the sintering temperature to below 900°C and a low TCC was maintained for fine grained microstructures.