Facile Synthesis of “Quench‐Free Glass” and Ceramic‐Glass Composite for <scp>LTCC</scp> Applications

Abstract

The 10 mol% ZnO –2 mol% B 2 O 3 –8 mol% P 2 O 5 –80 mol% TeO 2 ( ZBPT ) glass was prepared by quenching as well as slowly cooling the melt. The ZBPT glass prepared by both methods show similar microwave dielectric properties. ZBPT glass has an ε r of 22.5 (at 7 GHz), Q u × f of 1500 GHz, and τ f of −100 ppm/°C. The ceramic‐glass composites of Sr 2 Zn TeO 6 ( SZT ) and ZBPT is prepared through two convenient methods: ( a ) conventional way of co‐firing the ceramic with ZBPT glass powder and ( b ) a nonconventional facile route by co‐firing the ceramic with precursor oxide mixture of ZBPT glass at 950°C. In the former route, SZT + 5 wt% ZBPT composite sintered at 950°C showed moderately good microwave dielectric properties (ε r = 13.4, Q u × f = 4500 GHz and τ f = −52 ppm/°C). Although the SZT + 5 wt% ZBPT composite prepared through the nonconventional method also showed similar microwave dielectric properties (ε r = 13.8, Q u × f = 5300 GHz and τ f = −50 ppm/°C), the synthesis procedure is much simplified in the latter case. The composites are found to be chemically compatible with Ag. The composite containing 5 wt% ZBPT prepared through conventional and nonconventional ways shows linear coefficients of thermal expansion of 7.0 ppm/°C and 7.1 ppm/°C, respectively. Both the composites have a room‐temperature thermal conductivity of 2.1 Wm −1 K −1 .