Microstructure and microwave dielectric properties of 3D printed low loss Bi₂Mo₂O₉ ceramics for LTCC applications

Low sintering temperature, ultra-low loss microwave ceramics are envisaged as future dielectrics for fabricating low temperature co-fired ceramic (LTCC) components for 5G applications. Low sintering temperature bismuth molybdate β-Bi2Mo2O9 ceramic powders have been synthesised using a solidstate reaction method. Their additive manufacture and resulting microwave properties are reported for the first time. Optimum densification occurred for 3D printed samples sintered 4 hours at 670°C which resulted in a maximum relative density (ρr) of 92%, relative permittivity (εr) of 34, dielectric loss (tanδ) of 0.0007, giving a microwave quality factor (Qxf) of 10,050 GHz, properties attractive for LTCC applications.