Microwave dielectric properties and co-firing with copper of (Bi1−xCux)(Nb1−xWx)O4 ceramics

Effect of substitution of CuO and WO3 on the microwave dielectric properties of BiNbO4 ceramics and the co-firing between ceramics and copper electrode were investigated. The (Bi1−xCux)(Nb1−xWx)O4 (x = 0.005, 0.01, 0.015, 0.02) composition can be densified between 900 and 990 °C. The microwave dielectric constants lie between 36 and 45 and the pores in ceramics were found to be the main influence. The Q values changes between 1400 and 2900 with different x values and sintering temperatures while Qf values lie between 6000 and 16,000 GHz. The microwave dielectric losses, mainly affected by the grain size, pores, and the secondary phase, are discussed. The (Bi1−xCux)(Nb1−xWx)O4 ceramics and copper electrode was co-fired under N2 atmosphere at 850 °C and the EDS analysis showed no reaction between the dielectrics and copper electrodes. This result presented the (Bi1−xCux)(Nb1−xWx)O4 dielectric materials to be good candidates for LTCC applications with copper electrode.