Sintering behavior and microwave dielectric properties of B_2O_3-La_2O_3-MgO-TiO_2 based glass-ceramic for LTCC applications

摘要

Highlights•A new low temperature co-fired glass-ceramic material is fabricated in this paper.•The material is obtained by mixing B2O3-La2O3-MgO-TiO2glass with ceramic fillers.•The main phase of the glass-ceramic, LaBO3with optimum dielectric properties, crystallizes from the BLMT glass.•The glass-ceramic sintered at 860°C/20min reaches a maximum density of 4.25g/cm3.•And it shows optimum dielectric properties: εr=14.08, Q×f=41,600GHz and τf=−2.78ppm/°C.AbstractA new low temperature co-fired ceramic is fabricated from B2O3-La2O3-MgO-TiO2(BLMT) glass with ZnO, ZrO2and TiO2ternary 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 LaBO3and the filler ZnO reacts with and gets into the residue glass phase, while TiO2and ZrO2are 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 20min reaches a maximum density of 4.25g/cm3and has an excellent microwave dielectric properties with the dielectric constant of 14.08, quality factor of 41,600GHz (at 8GHz), and temperature coefficient of resonant frequency of −2.78ppm/°C.