Journal of the American Ceramic Society, Vol.102, No.3, 1218-1226, 2019
Ultralow temperature cofired BiZn2VO6 dielectric ceramics doped with B2O3 and Li2CO3 for ULTCC applications
In this paper, BiZn2VO6 doped with sintering aids of B2O3 and Li2CO3 is investigated in order to broaden the options for ultralow temperature cofired ceramics (ULTCC). The sintering behavior, microstructure, and microwave dielectric properties are studied. In combination with 1 wt% B2O3 and 5 wt% Li2CO3 dopants, the sintering temperature of the BiZn2VO6 ceramics was reduced from 780 degrees C to 600 degrees C. The co-doped BiZn2VO6 ceramics exhibited a low relative permittivity (epsilon(r)) of 8.9 and a quality factor (Q x f) of 13 000 GHz at a microwave-range frequency of 9 GHz. The temperature coefficient of resonant frequency ((f)) was measured to be -97 ppm/degrees C. The average linear coefficient of thermal expansion (CTE) was 7.2 ppm/degrees C. With the low sintering temperature, the co-doped BiZn2VO6 ceramics are compatible to be cofired with cost-effective aluminum electrodes. This was proven in a reaction test between the BiZn2VO6-B2O3-Li2CO3 and aluminum powders, in which no chemical interaction could be detected. These promising properties make the B2O3-Li2CO3 co-doped BiZn2VO6 an ideal candidate for ULTCC applications.
Keywords:aluminum electrode;low-temperature sintering;microwave dielectric property;sintering aid;ULTCC