Densification and Dielectric Properties of Ba_0.5Sr_0.5TiO₃-Glass Composites for LTCC Applications

Abstract

Barium zincoborate (BZB) glass was added to Ba 0.5 Sr 0.5 TiO 3 , and sintered at 875 o C for 2 h in air. When the BZB glass was added in quantities ranging from 15 to 20 wt%, the relative bulk density ranged from 93.1% to 94.2%, while the density decreased to roughly 81% thereafter up to 30 wt% glass addition. Quantitative XRD analysis showed that the Ba 0.5 Sr 0.5 TiO 3 filler was significantly dissolved into the BZB glass. However, no secondary phase was identified by XRD up to 30 wt% glass addition. The dielectric constant was about 130 to 140 at 1 MHz up to 20 wt% BZB glass addition, while it decreased to about 60 thereafter, which may be ascribed to decreased density, partial dissolution of the Ba 0.5 Sr 0.5 TiO 3 , and associated changes in the glass composition. The dielectric loss of the 20 wt% glass added specimen was 0.008.