Dielectric properties of low-temperature co-fired capacitor ceramics and MLCC devices with Ag inner electrodes

Low-temperature sintered 0.99((1-x)Bi0.5Na0.5TiO3-xNaNbO3)-0.01Sr0.8Na0.4Nb2O6 x )Bi 0.5 Na 0.5 TiO 3-xNaNbO 3 )-0.01Sr 0.8 Na 0.4 Nb 2 O 6 (100xNN, x = 0.25 and 0.30) ceramics and MLCC were successfully prepared, and the dielectric properties were systematically investigated. The dielectric permittivity at 25 degrees C (e ' 25 e ' 25 degrees C ) of 25NN ceramic is 1088, and the dielectric variation is small between-88 degrees C and 400 degrees C (|triangle e '/e ' 25 triangle e ' / e ' 25 degrees C | 5 15%, triangle e ' = e '- e ' 25 degrees C ). The dielectric loss tangent ( tans ) of 25NN ceramic is less than 0.02 between-65 degrees C and 358 degrees C. The MLCC with 25NN ceramic dielectrics and Ag inner electrode also has excellent dielectric stability, of which |triangle e '/e ' 25 triangle e ' / e ' 25 degrees C | is less than 15 % between-100 degrees C and 400 degrees C, and the dielectric loss is less than 0.02 between-88 degrees C and 373 degrees C. All these results indicate that the low- temperature sintered MLCC with Ag inner electrodes is a promising capacitor in automobile engines and aerospace fields, where the usage temperature is often above 300 degrees C.