Synthesis and microwave dielectric properties of Zn ₃ B ₂ O ₆ Ceramics for substrate application

A novel microwave dielectric ceramics of Zn ₃B ₂O ₆ for substrate application with low sintering temperature was synthesized by the solid-state reaction method. The sintering temperature ranges from 875°C to 950°C. The best microwave dielectric properties were obtained in the ceramic sintered at 925°C for 4 h with a permittivity ∼6.7, a Q × f value about 58, 500 GHz and a temperature coefficient value of -58 ppm/°C. From the X-ray diffraction, backscattered electron imaging results of the co-fired sample with 20 wt% silver additive, the Zn ₃B ₂O ₆ ceramic was found not to react with Ag at 950°C. The microwave dielectric properties and low sintering temperature of Zn ₃B ₂O ₆ ceramic make it a promising candidate for Low temperature co-fired ceramic applications as substrate.