Low Temperature Cofiring and Compatibility with Silver Electrode of Li₃NbO₄ Ceramics with B₂O₃ Addition

B₂O₃ was added to Li₃NbO₄ ceramics to promote the densification process of the ceramics at low temperatures (≤ 825 °C). When the B₂O₃ content was ≤ 0.5 wt %, a porous microstructure was developed for the specimens sintered at 825 °C. However, when the amount of B₂O₃ exceeded 0.5 wt %, the Li₃NbO₄ ceramics were well sintered due to the formation of a liquid phase containing B₂O₃. The microwave dielectric properties of the Li₃NbO₄ ceramics were influenced by the amount of B₂O₃, and the 0.75 wt % B₂O₃-added Li₃NbO₄ ceramic sintered at 825 °C for 2 h showed good microwave dielectric properties of ε_r = 15.3, Q×f = 24600 GHz, and τ_f = -45 ppm/°C. The compatibility between the dielectric and Ag electrode indicated that this ceramic might be a good candidate for microwave low temperature-cofired ceramics (LTCC) devices.