• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.33-34
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• 2008

Barium titanate (BaTiO3) is one of the most important dielectric materials for the electronic devices, such as MLCC (Multilayer Ceramic Capacitor). The thickness of the dielectric thin film in MLCC has become thinner and reached about 0.8 ${\mu}m$. Further down sizing is required for the higher performance. For this reason, we should take into account for the size effect of Barium titanate powders. In this study, we demonstrated that size effect for BaTiO3 (0.2 ~ 0.5 ${\mu}m$, hydrothermal BT) could be estimates by using dielectric properties analysis together with the powder properties.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.284-285
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• 2007

본 논문에서는 저소음 및 저 신호 왜곡 특성을 가지는 내환원성 유전체 원료를 개발하기 위하여 $(Ca_{0.7}Sr_{0.3})(Zr_{0.97}Ti_{0.03})O_3$에 $CaTiO_3$, $SrTO_3$, $BaTiO_3$를 첨가하여 이에 따른 유전 특성을 조사하였다. 첨가량의 조절 및 glass frit 첨가를 통하여 환원성 분위기에서도 유전율 80 ~ 100, 절연저항 (R*C) 500[ohm-F] 이상의 유전특성을 얻었다. 본 연구결과로 얻어진 유전재료를 적용하면 무소음 및 저 신호 왜곡 특성을 가지면서도 고 신뢰성의 MLCC를 제작할 수 있을 것으로 예상된다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.2
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• pp.137-143
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• 2008

High voltage MLCCs with C0G temperature coefficient characteristics could apply DC-DC invertor were investigated for its dielectric properties. Also we manufactured MLCC through various process and studied the characteristics of dielectric break down voltage [BDV] and dielectric property as the variation of thickness in the green sheet and how to pattern the internal electrode. As the thickness of green sheet is increase, the dielectric BDV per unit thickness is decreased. But as the pattern of internal electrodes were floated we could manufacture the high voltage MLCC maintained its dielectric BDV a unit.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.7
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• pp.645-651
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• 2008

To reduce noise in high frequency and distortion of signal, the composition of $(Ca_{0.7}Sr_{0.3})(Zr_{0.97}Ti_{0.03})O_3$ and $(Ba_{0.2}Ca_{0.4}Sr_{0.4})TiO_3$ was developed. The composition was not solid solution, but mixtures of various phases composed of Ca, Sr, Zr, Ti and Ba oxides. The dielectric constant increased, the quality factor and the insulation resistance decreased with $(Ba_{0.2}Ca_{0.4}Sr_{0.4})TiO_3$ content. The composition of $0.4(Ba_{0.2}Ca_{0.4}Sr_{0.4})TiO_3$ satisfied the electric characteristics and the temperature coefficient of dielectric constant (TCC). In addition, the glass frit and $MnO_2$ also affected the electric characteristics. From the result of the best fit simulation, $MnO_2$ 0.3 mol%, the glass frit 0.6 wt% showed the insulation resistance $906{\Omega}{\cdot}F$, the quality factor 821, and the dielectric constant 92. With the selected composition, MLCC capacitors sized $4.5{\times}3.2{\times}2.5mm$ were manufactured with 105 layered of the dielectric thickness $16{\mu}m$ using Ni inner electrode, They represented the capacitance $98{\sim}102$ nF, the quality factor 1,200 and the insulation resistance $1,500{\Omega}{\cdot}F$. Also, they had high break-down voltage with $107{\sim}115V/{\mu}m$, and satisfied the SL TCC characteristics.