Optimization of borosilicate glass/CaTiO₃‐TiO₂ composite via altering prefiring temperature and particle size

Abstract

Low‐temperature co‐fired ceramic (LTCC) with middle permittivity is very crucial to the miniaturization of components. Based on our previous study on the glass/CaTiO3‐TiO2 composite, prefiring temperature and particle size of CaTiO3‐TiO2 ceramic were optimized in this study to promote the performance of the composites. Comparing with our previous study, after being sintered with 50 wt% glass at 875°C, CaTiO3‐TiO2 ceramic prefired at 1275°C with particle size of 3.38 μm showed excellent properties of sintering density = 3.33 g/cm3, εr = 30.2, tan δ = 0.0005 (7 GHz). In addition, surface roughness of green tapes was also improved after optimization. The material has a good chemical stability and shrinkage matching with silver, making it a very promising candidate material for LTCC applications.

Effects of adding B2O3 on microwave dielectric properties of 0.9625MgTiO3‐0.0375(Ca0.5Sr0.5)TiO3 composite ceramics

“…So decreasing the sintering temperature of such microwave dielectric ceramics is also an important task for researches. As is known, there are three kinds of ways which are usually adopted to reduce the sintering temperature of microwave dielectric ceramics: preparing ceramic powders of particle size as small as possible, adopting low melting‐point additives and optimizing the sintering process 25‐30 . In particular, adopting low melting‐point additives is the most effective and least expensive method, because the liquid phases during sintering can promote the densification and gain coarsening at low temperature.…”