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Journal of the Korean Ceramic Society 2001;38(11): 1046. |
CuO ${B_2}{O_3}$첨가에 따른 $PbWO_4$-$TiO_2$세라믹스의 마이크로파 유전특성 |
최병훈, 이경호 |
순천향대학교 신소재화학공학부 |
Effects of CuO and ${B_2}{O_3}$Additions on Microwave Dielectric Properties of $PbWO_4$-$TiO_2$Ceramic |
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ABSTRACT |
Effects of B$_2$O$_3$and CuO addition on the microwave dielectric properties of the PbWO$_4$-TiO$_2$ceramics were investigated in order to use this material as an LTCC material for fabrication of a multilayered RF passive components module. We found that PbWO$_4$could be used as an LTCC material because of its low sintering temperature (8$50^{circ}C$) and fairy good microwave dielectric properties($varepsilon$$_{r}$=21.5, Q$times$f$_{0}$=37200 GHz and $tau$$_{f}$ =-31 ppm/$^{circ}C$). In order to stabilize $tau$$_{f}$ of PbWO$_4$, TiO$_2$was added to the PbWO$_4$and the mixture was sintered at 8$50^{circ}C$. A near zero $tau$$_{f}$ value (+0.2 ppm/$^{circ}C$) was obtained with 8.7 mol% TiO$_2$addition. $varepsilon$r and Q$times$f$_{0}$ values were 22.3 and 21400 GHz, respectively. It was believed that the decrement of Q$times$f$_{0}$ value with TiO$_2$addition was resulted from increasing grain boundary. In order to improve Q$times$f$_{0}$, various amounts of B$_2$O$_3$and CuO were added to the 0.913PbWO$_4$-0.087TiO$_2$mixture. The optimum amount of CuO was 0.05 wt%. At this addition, the 0.913PbWO$_4$-0.087TiO$_2$ceramic showed $varepsilon$$_{r}$=23.5, $tau$$_{f}$ =-2.2ppm/$^{circ}C$, and Q$times$f$_{0}$=32900 GHz after sintered at 8$50^{circ}C$. In case of B$_2$O$_3$addition, the optimum amount range was 1.0~2.5 wt% at which we could obtain following results; $varepsilon$$_{r}$=20.3~22.1, Q$times$f$_{0}$=48700~54700 GHz, and $tau$$_{f}$ =+2.4~+8.2ppm/$^{circ}C$. |
Key words:
LTCC, $PbWO_4$-$TiO_2$ceramic, ${B_2}{O_3}$, CuO, Microwave dielectric properties |
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