The effect of LMBS glass on the microwave dielectric properties of the Mg^sub 3^B^sub 2^O^sub 6^ for LTCC

The Mg^sub 3^B^sub 2^O^sub 6^ ceramics with lithium magnesium borosilicate (LMBS) glass were prepared at a lower sintering temperature. The effect of LMBS glass on the densification, phase development, microstructure and microwave dielectric properties of the Mg^sub 3^B^sub 2^O^sub 6^ ceramics was investigated. Adding the LMBS glass to Mg^sub 3^B^sub 2^O^sub 6^ ceramics lowered the sintering temperature of the ceramics to 950 from 1300 °C. The X-ray diffraction patterns showed that LMBS glass reacted with Mg^sub 3^B^sub 2^O^sub 6^, forming the Mg^sub 2^B^sub 2^O^sub 5^ and Mg^sub 2^SiO^sub 4^. Because of the high dielectric performance of these phases, the Mg^sub 3^B^sub 2^O^sub 6^ mixed with 35.0 wt% LMBS glass sintered at 950 °C had [straight epsilon] ^sub r^ = 6.5, Q × f = 21,000 GHz, and [tau] ^sub f^ = -49.5 ppm/°C at 6.55 GHz. Therefore, the Mg^sub 3^B^sub 2^O^sub 6^-LMBS composites are promising materials for LTCC applications.