Synthesis and Microwave Dielectric Properties of BBSZ-Zinc Silicate Based Material for LTCC Applications

The microwave dielectric properties and microstructures of zinc silicate (Zn2SiO4) ceramic with the addition of 5–20 wt.% B2O3-Bi2O3-SiO2-ZnO (BBSZ) glass have been studied for low-temperature co-fired ceramic (LTCC) applications. BBSZ glass helps in reducing the sintering temperature of zinc silicate (ZS) from about 1350°C to around 900°C in the form of ZS-glass composites. The zinc silicate powder was prepared following solid-state reaction technique, while BBSZ glass was prepared by standard melting and quenching method. Expectedly, the sintering studies indicate increasing sintered density between 91% and 97% with increasing sintering temperature from 875°C to 950°C. The sintering density is also seen to increase with increasing content of BBSZ, indicating liquid-phase sintering of the composites. Higher glass content in the composite leads to increased dielectric constant as well as dielectric loss. The results indicate that ZS with the addition of 5 wt.% of BBSZ glass, sintered at 925°C for 3 h, exhibits good microwave dielectric properties with a dielectric constant (εr) of 6.5 and quality factor (Q × f) of 20,754 GHz, which is suitable for LTCC applications.