• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.3
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• pp.208-213
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• 1998

Microwave dielectric properties of $BiNbO_4$ containing CuO and $V_2O_5$(BN ceramics). BN ceramic with 0.07wt% $V_2O_5$ and 0.03wt% CuO (BNC3V7) was sintered at $900^{\circ}C$ where it is possible for these to be co-fired with Ag electrode. The dielectric constant of 44.3, TCF (Temperature Coefficient of resonance Frequency) of 2 ppm/$^{\circ}$ and Q${\times}f_o$ value (product of Quality value and resonance Frequency) of 22,000GHz could be obtained from those ceramics. It is observed that orthorhombic structure was stable $1000^{\circ}C$. As sintering temperature increases, the dielectric properties decreased. The main reasons were abnormal grain growth and the main peak of triclinic moved from the main peak of orthorhombic.

• Electrical & Electronic Materials
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• v.9 no.9
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• pp.900-905
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• 1996

We have investigated dielectric properties of low fired ceramics BiNbO$_{4}$ containing 0.05[wt%] V$_{2}$O$_{5}$ and x[wt%l Cr$_{2}$O$_{3}$ (x=0, 0.2, 0.4, 0.8, 1.2). By substituting Cr for Bi, dielectric constant .epsilon.$_{r}$ and quality factor Q.f increased and temperature coefficient of resonant frecquency .tau.$_{f}$ changed to positive value. In the composition of BiNbO$_{4}$+0.05 [Wt%] V$_{2}$O$_{5}$+0.8[wt%]Cr$_{2}$O$_{3}$ sintered at 960[.deg. C], we could obtain microwave dielectric properties of .epsilon.$_{r}$=49, Q.f.simeq.3000[GHz](at 4.8[GHz]), .tau.$_{f}$.simeq.0[ppm/.deg. C]. As the above ceramics can be sintered near 960[.deg. C], it is applicable to multilayer microwave device with Ag conductor.tor.tor.tor.

• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.42.2-42
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• 2003

• Korean Journal of Materials Research
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• v.8 no.11
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• pp.1043-1047
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• 1998

The effect of CuO and CdO addition on the microwave dielectric properties of $BiNbO_4$, ceramics were investigated. As the content of CdO increased, sintered density and quality factor decreased. With increasing sintering temperature, both the dielectric constant and quality factor increased. In the case of specimen sintered at $960^{\circ}C$ with addition of 0.03 wt% of CuO and CdO, respectively. the microwave dielectric properties obtained were dielectric constant of 41.2, quality factor ($Q{\times}f_0$) of 6,500 (at 5.6GHz), temperature coefficient of resonant frequency of $3ppm^{\circ}C$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.4
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• pp.281-287
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• 1998

$BiNbO_4$ ceramics doped with 0.07wt% $V_2O_5$ and 0.03wt% CuO (BNC3V7) were sucessfully sintered at $900^{\circ}C$ through the firing process with Ag electrode. The BNC3V7 shows typically Dielectric constant of 44.3, Thermal Coefficient of resonance Frequency(TCF) of 2 ppm/$^{\circ} and $Qxf_o$ value of 22,000 GHz. The laminated chip Low Pass Filter (LPF) is very sensitive to chip processing parameters, was confirmed by the computer simulation as a function of Q(Quality factors), filter size, capacitor layer thickness, inductor pattern widths. The multilayer type LPF was fabricated by screen-printing with Ag electrode after tape casting and then compared with the simulated characteristics. The results show that characterization of band pass width was similar to that of designed ones.

• Journal of the Korean Ceramic Society
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• v.39 no.12
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• pp.1190-1196
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• 2002

Microwave dielectric properties and multilayer characteristics $(1-x)BiNbO_4-xCaNb_2O_6$ (0${\le}$x${\le}$1.0) ceramics were investigated as a function of $CaNb_2O_6$ content. In the composition range of 0.25${\le}$x${\le}$0.75, the mixture phases of $BiNbO_4$ with stibotantalate structure and $CaNb_2O_6$ with columbite structure were detected and secondary phase or phase transition were not detected. Dielectric constant (K) of $(1-x)BiNbO_4-xCaNb_2O_6$ ceramics was largely dependent on the existing phase and could be estimated by the dielectric mixing rule calculated from maxwell equation. Typically, dielectric constant (K) of 26, quality factor (Qf) of 4300 GHz and Temperature Coefficient of resonant Frequency (TCF) of -18 ppm/${\circ}C$ were obtained for $0.5BiNbO_4-0.5CaNb_2O_6$ specimens with 0.8 wt% $CuV_2O_6$ sintered at 1000${\circ}C$ for 3h. The deviation of X-Y shrinkage and camber value of the multilayers obtained from $0.5BiNbO_4-0.5CaNb_2O_6$ green sheet sintered at 850∼950${\circ}C$ for 20 min. were smaller than those of $BiNbO_4$ multilayers.

• Korean Journal of Materials Research
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• v.6 no.12
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• pp.1186-1191
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• 1996

CuO의 첨가가 BiNbO4 세라믹스의 마이크로파 유전특성과 소결거동에 미치는 영향에 대하여 연구하였다. CuO의 첨가량이 증가함에 따라 액상의 생성에 의해 소결성이 증가하여 시편의 밀도는 증가하며 유전상수는 소결온도가 증가함에 따라 증가하는 경향을 보였다. Qxfo값은 CuO 첨가량이 0.065wt%이고 소결온도가 94$0^{\circ}C$일 때 최대값을 나타내며 그 이상 CuO 첨가량을 증가하였다. 소결온도 92$0^{\circ}C$-96$0^{\circ}C$, 소결시간 2시간일 때의 고주파 유전특성으로는 유전상수가 43.6, Qxfo값이 13,200 이상, $\tau$f =-14.36ppm/$^{\circ}C$을 얻었다.

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.11a
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• pp.25-25
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• 1998

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.204.1-204
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• 2003

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.284-284
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• 2007

In this study, the microwave dielectric property variations of (1-x)$BiNbO_4-(x)ZnNb_2O_6$ composites (x=0.3, 0.5 and 0.7) with 10wt% zinc borosilicate(ZBS) glass was investigated as a function of the substitution of $ZnNb_2O_6$ with a view to applying thes system to LTCC technology. The all composition addition of 10wt% ZBS glass ensured a successful sintering below $900^{\circ}C$. In addition, a small amount of $Bi_2SiO_5$ as the secondary phase was observed in the all composition. The substitution of $ZnNb_2O_6$ on the $BiNbO_4$ composites increased the $Q{\times}f$ values, but it decreased the sinterability and dielectric constant due to the high sintering temperature and low dielectric constant of $ZnNb_2O_6\;than\;BiNbO_4$ ceramics. The increasing of $ZnNb_2O_6$ content from 0.3 to 0.7 in the (1-x)$BiNbO_4-(x)ZnNb_2O_6$ composites with 10wt% ZBS glass sintered at $900^{\circ}C$ demonstrated 28.1~15.6 in the dielectric constant$({\varepsilon}_r)$, 5,500~8,700GHz in the $Q{\times}f$ value.