Technical Glasses

Structural, Dielectric, and Thermal Properties of Pb Free Molybdate Based Ultralow Temperature Glass

“…A similar observations are also visible in the high-frequency region from 5 MHz to 1 GHz measured with an impedance analyzer (Figure b), where the relative permittivity decreases from 5.11 to 4.93. The decreases in the relative permittivity, especially at a lower frequency, may be associated with electrode polarization as well as the effect of orientational polarization during the measurement. , The dielectric loss tangent decreases from 0.02 to 0.001 at this frequency range of 5 MHz to 1 GHz being moderately low against the earlier reported values for low loss glasses …”

“…Over the last two decades, several approaches such as chemical synthesis, , use of starting powders with smaller particle size, and liquid phase sintering by adding low melting additives , have been adopted for reducing the sintering temperature of low loss ceramic materials. There are several recent reports on ultralow temperature sinterable ceramic materials with and without glass addition. − Glasses with good dielectric properties for LTCC materials processing are also reported in the literature and are commercially available . Most of the reported low-temperature glasses are PbO–B 2 O 3 based usually with additives such as SiO 2 , ZnO, and Al 2 O 3 having glass transition temperature, relative permittivity, and Q f in the range of 390–500 °C, 10–20, and 500–1000 GHz, respectively. ,, The ULTCC materials can be classified into category I (sintering temperature ≤400 °C) and category II (sintering temperature >400–700 °C) materials.…”

“…There are several recent reports on ultralow temperature sinterable ceramic materials with and without glass addition. − Glasses with good dielectric properties for LTCC materials processing are also reported in the literature and are commercially available . Most of the reported low-temperature glasses are PbO–B 2 O 3 based usually with additives such as SiO 2 , ZnO, and Al 2 O 3 having glass transition temperature, relative permittivity, and Q f in the range of 390–500 °C, 10–20, and 500–1000 GHz, respectively. ,, The ULTCC materials can be classified into category I (sintering temperature ≤400 °C) and category II (sintering temperature >400–700 °C) materials. Classification of these ultralow temperature ceramics is based on electrode metal compatibility as well as low-temperature fabrication process with environmentally friendly materials .…”