Low-temperature sintering and microwave dielectric properties of Ca[(Li<inf>1/3</inf>Nb<inf>2/3</inf>)<inf>0.8</inf>Ti<inf>0.2</inf>]<inf>3−δ</inf> with glass frit added

In accordance with the trend for mobile terminals to be high intensity and to have thinner layers, low temperature co-fired ceramics (LTCC) materials with outstanding dielectric loss characteristics and diverse dielectric constants have been in demand, and the need for high-strength materials that can withstand external shocks has increased. Ca[(Li<inf>1/3</inf>Nb<inf>2/3</inf>)<inf>1−x</inf>Ti<inf>x</inf>]O<inf>3−δ</inf> (CLNT) has a quality factor over 14,000 and τ<inf>f</inf> ≤ 10 when the dielectric constant is 41 ∼ 46, but its sintering temperature is high at 1150 °C. Therefore, it cannot be used as a LTCC component. This study aimed to lower the sintering temperature to 900 °C by adding a low-melting-point glass such as B<inf>2</inf>O<inf>3</inf>·SiO<inf>2</inf>·BaO and B<inf>2</inf>O<inf>3</inf>·SiO<inf>2</inf>·Al<inf>2</inf>O<inf>3</inf>. As the glass content in CLNT was increased from 10 wt% to 20 wt%, the density and the Q·f<inf>0</inf> property decreased, and the dielectric constant rose. When B<inf>2</inf>O<inf>3</inf>·SiO<inf>2</inf>·BaO was added to CLNT at 15 wt%, the dielectric constant was found to be 27, the Q·f<inf>0</inf> property to be 3470, and the τ<inf>f</inf> to be −18 ppm/°C. When B<inf>2</inf>O<inf>3</inf>·SiO<inf>2</inf>·Al<inf>2</inf>O<inf>3</inf> was added to CLNT at 10 wt%, the dielectric constant was 20, the Q·f<inf>0</inf> property was 3990, and the τ<inf>f</inf> was −15 ppm/°C. As such, in both cases, excellent dielectric properties were observed.