• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.72-74
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• 2014

Multilayer ceramic capacitor (MLCC) makes acoustic noise of electronic devices. Conversed piezoelectric effect of dielectric substance consists of $BaTiO_3$ causes vibration of MLCC so it must be analyzed to reduce the noise. Thus, finite element model for piezoelectric analysis of MLCC was constructed in this paper. Piezoelectric characteristics of MLCC was considered for the accurate simulation result. Displacement response for sinusoidal voltage signal was measured and simulation result was verified with test result.

• Transactions of the Society of Information Storage Systems
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• v.10 no.2
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• pp.61-64
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• 2014

Vibration and acoustic noise arise from the Multilayer Ceramic Capacitor (MLCC) because of the piezoelectric effect of dielectric substance which consists of $BaTiO_3$. However, the phenomenon is not analyzed clearly because the MLCC shows different behavior compare with ordinary piezoelectric substance like PZT. Thus, MLCC was tested under the several DC bias conditions and heat treatment effect was also tested and analyzed in this paper. From the test, MLCC shows not only piezoelectric effect but also another physical phenomenon like electrostriction. Also, it was verified that DC bias affect to the piezoelectric constant of MLCC.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.2
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• pp.118-123
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• 2007

The purpose of this work was to investigate the design and fabrication process effects on electrical properties in high capacitance multilayer ceramic capacitor (MLCC) with nickel electrode. Dielectric breakdown voltage and insulation resistance value were decreased with increasing stack layer number, but dielectric constant and capacitance were increased. With increasing green sheet thickness, dielectric breakdown voltage, C-V and I-V properties were also increased. The major reasons of the effects were thought to be the defects generated extrinsically during fabrication process and interfacial reactions formed between nickel electrode and dielectric layer. These investigations clearly showed the influence of both green sheet thick ness and stack layer number on the electrical properties in fabricating the MLCC.

• Transactions on Electrical and Electronic Materials
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• v.10 no.1
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• pp.5-8
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• 2009

The reliability of multilayer ceramic capacitor with active thin dielectric layer was investigated by highly accelerated life test at various stress condition. The distribution of multilayer ceramic capacitor failure times is plotted as a function of time from Weibull distribution function. According to the test result, voltage acceleration factor is obtained from 2.24 to 2.96. The acceleration by temperature is much higher than other values of active thick dielectric layer. It is clear that median time to failure is affected by the stress voltage for high volumetric efficiency ceramic capacitors with active thin dielectric layer. The degradation under stress of voltage involves electromigration and accumulation of oxygen vacancy at Ni electrode interface of cathode.

• 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.

• Journal of the Korean Ceramic Society
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• v.46 no.2
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• pp.155-160
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• 2009

The reliability could be one of the essential properties for multilayer ceramic capacitor (MLCC) using in various electronic devices and the concentration and mobility of oxygen vacancy would play important role in the reliability. To investigate the migration behavior of oxygen vacancies, thermally stimulated depolarization current (TSDC) is adopted. In dielectric material of X5R MLCC, the TSD-Current peak observed around 150$^{\circ}C$ and 200$^{\circ}C$ which represented the migration of oxygen vacancy. Substituting Yttrium for Dysprosium in X5R MLCC showed higher migration activation energy and lower TSD current density.

• Transactions on Electrical and Electronic Materials
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• v.13 no.4
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• pp.181-184
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• 2012

$BaTiO_3$ based multilayer ceramic capacitors with Ni electrodes can be explained as 2-2 composites with different thermal expansion coefficient and sintering behaviors. To achieve the high capacitance and reliability of MLCCs, a homogenous Ni electrode configuration with high connectivity is required. We controlled the heating rates during sintering to achieve densification by suppressing grain growth. Experimental results revealed that a large heating rate gave high connectivity of Ni electrode, high capacitance, small dissipation factor, high breakdown voltage, and high reliability of MLCC chips.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.3
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• pp.214-220
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• 2022

This paper proposes a test device designed for developing a high-voltage multilayer ceramic capacitor (MLCC). The proposed topology consists of an energy recovery circuit for charging/discharging capacitor, a flyback converter, and a boost converter for supplying power and a bias voltage application to the energy recovery circuit. The energy recovery circuit designed with a half-bridge converter has auxiliary switches operating before the main switches to prevent excessive current from flowing to the main switches. A prototype has been designed to verify the reliability of target capacitors following the voltage fluctuation with a frequency range below 65 kHz. To conduct high root mean square (RMS) current to the capacitor as a load, the MLCC test was conducted after the topology verification was completed through the film capacitor as a load. Through the agreement between the RMS current formula proposed in this paper and the MLCC test results, the possibility of its use was demonstrated for high-voltage MLCC development in the future.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.348-348
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• 2005

High capacitance MLCC has been enabled through the use of nickel electrodes to produce thinner layers at acceptable costs. High capacitance MLCC devices offer significant advantages to electrolytics such as tantalum and aluminum ; Lower ESR for high frequency applications. Non-polarized. Many process improvement have enabled this technology Higher dielectric constants Thinner dielectric and electrode layers through BME More accurate layer construction. This study is high capacitance MLCC electrical propertics. reliability, Analysis on DOE(Design Of Experiment) of the electical propertics.

• 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.