Fabrication and microwave dielectric properties of CuO-B2O3-Li2O glass-ceramic with ultra-low sintering temperature

CuO-B2O3-Li2O (CBL) glass-ceramic with a composition of 32 wt% CuO - 63 wt% B2O3 - 5 wt% Li2O was prepared through conventional glass-ceramic route. The CBL glass-ceramic could be densified well by sintering at 625 degrees C for 30 min. The X-Ray diffraction (XRD) and transmission electron microscopy (TEM) analysis indicated that the CuB2O4 phase was dominated in the sintered glass-ceramic, which showed excellent microwave dielectric properties with epsilon(r) = 5.84, Qxf = 10120 GHz (at 13.44 GHz); and tau(f) = -33 ppm/degrees C. Furthermore, the CBL material is chemically compatible with both silver (Ag) and aluminuni (Al) electrodes at their sintering temperatures. These properties indicate that the CBL glass-ceramic might be a promising ultra-low temperature co-fired ceramic (ULTCC) material for packaging substrate applications.