Microwave dielectric properties of BaO–4.3TiO2–0.5ZnO ceramics with BaCu(B2O5)

Effect of BaCu(B2O5) (BCB) addition on microwave dielectric properties and sintering behaviors of BaO–4.3TiO2–0.5ZnO system (BTZ) ceramics were investigated to develop middle-k dielectric composition with low sintering temperatures. When a small amount of BCB was added to BTZ system, the sintering temperature can be lowered from 1100 °C to 900 °C due to the formation of BCB liquid phase. The system added with 7 wt% BCB was sintered at 900 °C for 2 h and ɛr of 31, Q × f of 18,200 GHz and τf of 3.8 ppm/°C were obtained. The suitability of BTZ ceramics for tape casting and cofiring with Ag electrodes was investigated, and no evidence of chemical reaction between Ag and ceramics was observed. The dielectric properties of the stacked multilayer plate without any electrodes were also measured. The result shows that the as-prepared BTZ ceramics are suitable for low-temperature co-fired ceramics applications.