Environmental Friendly Approach for the Development of Ultra-Low-Firing Li₂WO₄ Ceramic Tapes

Abstract

Ultra-low-temperature co-fireable Li2WO4 substrate has been developed using an environmental friendly tape-casting technique. The nonaqueous tape-casting slurry comprised of an eco-friendly binder-solvent system consisting of polypropylene carbonate as binder and dimethyl carbonate as solvent. The structural, thermal, morphological, rheological, and electrical properties of the sintered substrate is investigated. The bulk ceramics sintered at 650 °C possess a relatively high thermal expansion coefficient of about 16 ppm/°C. The thermal conductivity of sintered tape measured at room temperature was about 2.6 W/m·K. The sintered substrate exhibits excellent microwave dielectric properties with a relative permittivity of 5.4 and a very low dielectric loss of 9.21 × 10–5 at 5 GHz and is co-fireable with Ag electrode.