A New Microwave Dielectric Ceramic for LTCC Applications

Abstract

A new low‐sintering temperature microwave dielectric ceramic, the Li 2 TiO 3 solid solution, was found and investigated in the Li 2 O–Nb 2 O 5 –TiO 2 system. The compound with the composition of Li 2.081 Ti 0.676 Nb 0.243 O 3 crystallizes as a monoclinic structure. This new microwave dielectric ceramic shows a relatively low permittivity (∼20), high Q × f values up to 50 000 (7.8 GHz), and near‐zero temperature coefficients (13 ppm/°C), which were obtained via sintering at 1100°C. The addition of ≤2 wt% B 2 O 3 was very effective in lowering the sintering temperature ( T s ), and dense ceramics could be obtained at T s ≤900°C. The addition of B 2 O 3 does not induce apparent degradation in the microwave properties but lowers the τ f value to near zero. It is obvious that the ceramics could be promising candidates for multilayer low‐temperature co‐fired ceramics applications.