Effect of silica addition on microstructure, sintering behavior, and dielectric properties of borosilicate glass/alumina composites for LTCC application

CaO-B 2 O 3 -SiO 2 /Al 2 O 3 /SiO 2 composites were developed for low-temperature co-fired ceramic (LTCC) applications, and the sintering behavior, phase compositions, microstructure, dielectric properties, and mechanical properties were investigated in the present work. The results showed that an appropriate amount of silica could reduce the dielectric constant and improve the dielectric properties of the composite material, which is of great significance for improving the signal transmission rate, and reducing the signal transmission loss and delay. The CBS/Al 2 O 3 /SiO 2 glass ceramics with 32 wt% Al 2 O 3 and 16 wt% SiO 2 sintered at 850 °C for 30 min achieved excellent comprehensive performance with buck density of 2.88 g/cm 3 , ε r of 6.76, tanδ of 1.12 × 10 −3 (7 GHz), CTE value of 7.42 ppm/ °C, and flexural strength of 207.8 MPa. Moreover, the composites matched well with the silver electrode, establishing an extremely promising material for LTCC applications.