Sintering behavior and microwave dielectric properties of B2O3-La2O3-MgO-TiO2 based glass-ceramic for LTCC applications

Abstract A new low temperature co-fired ceramic is fabricated from B 2 O 3 -La 2 O 3 -MgO-TiO 2 (BLMT) glass with ZnO, ZrO 2 and TiO 2 ternary fillers, and the sintering behavior, crystalline phases, microstructures and microwave dielectric properties of the glass-ceramics is investigated. The results show that its sintering process starts at about 640 °C and ends up mostly at higher than 710 °C. During the process, BLMT glass crystallizes forming LaBO 3 and the filler ZnO reacts with and gets into the residue glass phase, while TiO 2 and ZrO 2 are stable. With increasing sintering temperature, dielectric constant and temperature coefficient of resonant frequency of the glass-ceramic decrease, while the quality factor firstly increases and then decreases. Typically, the glass-ceramic sintered at 860 °C for 20 min reaches a maximum density of 4.25 g/cm 3 and has an excellent microwave dielectric properties with the dielectric constant of 14.08, quality factor of 41,600 GHz (at 8 GHz), and temperature coefficient of resonant frequency of −2.78 ppm/°C.