Additively manufactured ultra-low sintering temperature, low loss Ag₂Mo₂O₇ ceramic substrates

Ultra-low sintering temperature silver molybdenum oxide (Ag₂Mo₂O₇) ceramics have been printed using direct ink writing (a material extrusion additive manufacturing process) for the first time. An optimum densification conditions of 460 °C / 2 h was determined, resulting in relative permittivity, ε_r = 13.45, dielectric loss, tanδ = 0.0005, microwave quality factor, Q × f = 17,056 GHz and the temperature coefficient of resonant frequency τ_f = −121 ppm/°C. The results were comparable to the dielectric properties of conventionally fabricated ceramics. A series of metal/ceramic antenna designs were produced via dual-printing and co-firing, to demonstrate the potential of Ag₂Mo₂O₇, to be used as a co-firable dielectric material for functional integrated circuits and/or microwave RF devices through multi-material direct ink writing.