• 한국공작기계학회논문집
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• 제17권2호
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• pp.110-113
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• 2008

Embedded capacitor technology is one of the effective packing technologies for further miniaturization and higher performance of electric packaging system. In this paper, the embedded capacitors were simulated and fabricated in 8-layered printed circuit board employing standard PCB processes. The composites of barium titanante($BaTiO_3$) powder and epoxy resin were employed for the dielectric materials in embedded capacitors. Theoretical considerations regarding the embedded capacitors have been paid to understand the frequency dependent impedance behavior. Frequency dependent impedance of simulated and fabricated embedded capacitors was investigated. Fabricated embedded capacitors have lower self resonance frequency values than that of the simulated embedded capacitors due to the increased parasitic inductance values. Frequency dependent capacitances of fabricated embedded capacitors were well matched with those of simulated embedded capacitors from the 100MHz to 10GHz range. Quality factor of 20 was observed and simulated at 2GHz range in the 10 pF embedded capacitors. Temperature dependent capacitance of fabricated embedded capacitors was presented.

• 전기학회논문지
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• 제57권7호
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• pp.1229-1234
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• 2008

In this work, ultra high-voltage (17 - 50 kV AC), reliable 80 pF mica capacitors for partial discharge system application were investigated. Mica was used as the dielectric of the capacitors. Using the conservative design rule, over 3 individual $50\;{\mu}m$ thick mica sheets with a size of 30mm{\times}35mm were used with lead foils to form a parallel capacitor element and 20 mica sheets were interleaved with lead foils to form a series stack of parallel capacitor element to meet the requirements of the capacitors. The dimensions of the fabricated 80 pF capacitors for 17 kV AC and 50 kV AC were $90\;mm{\times}90\;mm$ and $95\;mm{\times}180\;mm$, respectively. The high-frequency characteristics of the capacitance (C) and dissipation factor (D) of the developed capacitors were measured using a capacitance meter. The developed capacitors exhibited C of 79.5 - 87.5 pF, had D of 0.001% over the frequency ranges of 150 kHz to 50 MHz, had a self-resonant frequency of 65 MHz, and showed results comparable to those measured for the capacitors prepared recently by $Adwel^{Tm}$. The developed capacitors also showed excellent characteristics for thermal shock test and temperature cycling test.

• 한국표면공학회지
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• 제35권3호
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• pp.127-132
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• 2002

High speed performance of ferroelectric Pb(Zr,Ti)$O_3$ (PZT) based capacitors is reported. La substitution up to 10% was performed to systematically lower the coercive and saturation voltages of epitaxial ferroelectric capacitors grown on Si using a ($Ti_{0.9}$ /$Al_{0.1}$ )N/Pt conducting barrier composite. Ferroelectric capacitors substituted with 10% La show significantly lower coercive voltage compared to capacitors with 0% and 3% La. This is attributed to a systematic decrease in the tetragonality (i.e., c/a ratio) of the ferroelectric phase. Furthermore, the samples doped with 10% La showed dramatically better retention and pulse width dependent polarization compared to the capacitors with 0% and 3% La. These capacitors show promise as storage elements in low power high density memory architectures.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2001년도 추계 기술심포지움
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• pp.61-66
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• 2001

In this research, the design parameters of embedded capacitors are extracted by modeling and fabrication. The traditional library of capactor has a few problems in applying the circuit. Its capacitance is discrete, so target values in any circuit often can't be obtained in library, To solve this problem, the characteristics of capacitors are detected in the variation with the shape and structure, and then the capacitors with the expected reactance value at target frequency are obtained, In this procedure, 3-dimensional structure simulation is performed to predict the characteiristics of capacitors.

• 전기학회논문지
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• 제60권10호
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• pp.1888-1894
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• 2011

In this study, large-current (75 - 400 A), high-voltage (500 - 1000 $V_{rms}$), reliable capacitors with capacitances (C) of 100 - 1000 nF were developed for energy storage facility applications. Mica was used as the dielectric of the capacitors. In order to form a parallel stack of a capacitor element, 50 ${\mu}m$ thick mica sheets with a size of $30mm{\times}35mm$ were used with lead foils for the plate lead type of mica capacitors (HCM-L), while the same sizes of mica sheets coated by Ag paste were employed with lead foils for the parallel plate terminal type (HCM-C). The developed capacitors exhibited well behaviored device characteristics which meet the requirements of the capacitors. The developed capacitors also showed excellent characteristics for thermal shock test. The stability characteristics of developed capacitors for large current stress was superior to those measured for the capacitors prepared recently by CDETm.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.135-137
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• 2004

In this study we'll deal with the small-sized metalized film capacitors with large capacity which head have $5mm{\times}5mm{\times}2.5mm$ dimension. The lead wire is used to weld at both sides of capacitors. At that time the position gap between the welding machine and lead wire supplier would cause the welding error. Also, during the tapping processing of metalized film capacitors, the interval error among the capacitors, the length error of lead frame attached at the capacitors, and the straightness distortion of the lead frame could happen. As mentioned, four kinds of error parameters will be measured and analyzed by using the automatic visual inspection system that is implemented with CCD camera, optical parts, background lighting, and image processing algorithms. Finally we are able to achieve success rate above 99% to detect the welding faults of capacitors in the field test.

• 전력전자학회논문지
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• 제18권2호
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• pp.145-152
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• 2013

Electrolytic capacitors used for smoothing DC link voltage is one of the major root causes of fault in power electronic system. The aging of aluminum electrolytic capacitors is expressed by the increase of their equivalent series resistance (ESR) and the reduction of their capacitance. Thus, the proposed technique in this paper is to measure capacitance, by comparing energy loss of DC link capacitors with stator resistor in electric machine. Condition of DC link capacitors can be estimated from the capacitance decrease rate between initial and aged capacitors. The results show that the proposed technique provides an easy, widely applicable and simple low cost solution for detecting dc link capacitor degradation.

• 한국결정성장학회지
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• 제12권3호
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• pp.157-160
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• 2002

The ferroelectric domain variation and electrical performance of $Pb(Zr,Ti)O_{3}$ (PZT) based capacitors through La additions were systematically studied. La substitution up to 10 % was performed to lower the coercive and saturation voltages of epitaxial ferroelectric capacitors grown on Si using a (Ti_{0.9}Al_{0.1})N/Pt$ conducting barrier composite. Ferroelectric capacitors substituted with 10 % La show significantly lower coercive voltage compared to capacitors with 0 % and 3 % La. This is attributed to a systematic microstructure change into $180^{\circ}C$ domain and decrease in the tetragonality (i.e., c/a ratio) of the ferroelectric phase. These capacitors show promise as storage elements in low power memory architectures.

• ETRI Journal
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• 제31권6호
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• pp.741-748
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• 2009

We present an analysis of microstrip coupled lines (MCLs) used to improve the stability of a 60 GHz narrowband amplifier. The circuit has a 4-stage structure implementing MCLs instead of metal-insulator-metal (MIM) capacitors for the unconditional stability of the amplifier and yield enhancement. The stability parameter, U, is used to compare the stability of MCLs with that of MIM capacitors. Experimental results show that MCLs are more stable than MIM capacitors with the same capacitances as MCLs because the parasitic parallel resistances of MCLs are lower than those of MIM capacitors. Moreover, the bandwidth of an amplifier using MCLs is narrower than one using MIM capacitors because the parasitic series inductances of MCLs are higher than those of MIM capacitors.

• 한국재료학회지
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• 제9권5호
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• pp.509-514
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• 1999

Interest in the integrated capacitors, which make it possible to reduce the size of and to obtain improved electrical performance of an electronic system, is expanding. In this study, $Ta_2$O\ulcorner thin film capacitors for MCM integrated capacitors were fabricated on a Upilex-S polymer film by DC magnetron reactive sputtering and the effects of low temperature annealing at various atmospheres and substrate surface morphology on the capacitor characteristics were discussed. The low temperature($150^{\circ}C$) annealing produced improved capacitor yield irrespective of the annealing at mosphere. But the leakage current of the $O_2$-annealed film was larger than that of any other films. This is presumably mosphere. But the leakage current of the $O_2$-annealed film was larger than that of any other films. This is presumably due to the change of the $Ta_2$O\ulcorner film surface by oxygen, which was explained by conduction mechanism study. Leakage current and breakdown field strength of the capacitors fabricated on the Upilex-S film were 7.27$\times$10\ulcornerA/$\textrm{cm}^2$ and 1.0 MV/cm respectively. These capacitor characteristics were inferior to those of the capacitors fabricated on the Si substrate but enough to be used for decoupling capacitors in multilayer package. Roughness Analysis of each layer by AFM demonstrated that the properties of the capacitors fabricated on the polymer film were affected by the surface morphology of the substrate. This substrate effect could be classified into two factors. One is the surface morphology of the polymer film and the other is the surface morphology of the metal bottom electrode determined by the deposition process. Therefore, the control of the two factors is important to obtain improved electrical of capacitors deposited on a polymer film.