Improved microwave dielectric characteristics of low-firing CaO–SiO 2 ceramics with LiF additive

As one of the main crystalline phases of A6 tape (Ferro Corp.), CaSiO 3 is a promising candidate with excellent microwave dielectric traits, including a low dielectric constant and a low dielectric loss. The optimum sintering temperature of CaSiO 3 ceramic can be reduced from 1250 to 925 °C with a high Q×f value after adding LiF additive. Therefore, the phase constitutions, microstructure, low-temperature sintering behaviors, and microwave dielectric traits of CaSiO 3 ceramics doped with 0.5 ~ 3 wt% LiF were investigated in detail. In particular, the outstanding microwave dielectric traits ( ε r = 6.3, Q×f = 32,435 GHz, τ f = − 28.51 ppm/°C) achieved in the CaSiO 3 ceramics with 1 wt% LiF are compatible with silver when sintering at 875 °C, showing great potential for the application of low-temperature co-fired ceramic (LTCC) technology.