Abstract
Low-temperature sintering ceramics with high dielectric permittivity and low loss are highly valuable to the communication industry. Additive Manufacturing (AM) exhibits excellent potential to process a wide range of engineering materials and deliver complex three-dimensional structures in various scales, with several benefits over traditional manufacturing methods used in electronics manufacturing. Therefore, the advent of AM has offered a radically new way of designing and manufacturing electronic and communication components with tailored performance. In this work, a stable ink has been formulated from ultra-low loss dielectric bismuth molybdate (Bi2Mo2O9) ceramics. The formulated ink exhibited suitable rheological properties responsive to the direct ink writing technique. The 3D printed components with good structural integrity and spatial resolution were sintered at 670°C for 4 hours using the conventional heating method, achieving > 94% density. A series of components with varying shapes and designed porosities were fabricated using the extrusion 3D printing method. The relative permittivity (εr) and loss tangent (tanδ) for the 3D printed and sintered Bi2Mo2O9 solid components were found to be 36.5 and 0.0005, respectively, at ∼8GHz, and the values can be tailored using designed porosity. The dielectric performance was found to be excellent and stable even at very high-frequency regimes (beyond 5G) between 70–90 GHz. Further, the addition of metallic infills in the designed pores of the ceramic scaffolds resulted in an increase in permittivity values. The preliminary investigation exhibited the potential to fabricate ceramic components for high-frequency applications via the design freedom offered by AM, that can enable further miniaturization of future communication devices.
