• 한국전기전자재료학회논문지
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• 제21권2호
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• pp.144-150
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• 2008

Recently, there has been growing interest in low loss and low dielectric constant material for LTCC application, as the frequency range for electronic devices increases. This study was designed to evaluate the effect of cordierite filler for low dielectric constant LTCC material. From the previous experiments, two glass compositions of B-Si-Al-Zn-Ba-Ca-O and B-Si-Al-Sr-Ca-O system, were chosen. Each powder of two glass compositions was sintered respectively with commercial cordierite powder in temperature range from $800^{\circ}C\;to\;900^{\circ}C$. Crystalline cordierite and glass peaks were affected only with two factors of composition and sintering temperature among various factors. With the optimized condition of two cordierite/glass compositions, obtained dielectric constant was below 5.5 and quality factor was above 1,000. Closed pore of sintered body was controled by sintering temperature and sintering time. When cordierite/glass composite with ratio of 5.5:4.5 was sintered at $900^{\circ}C$, densification was sufficient with good dielectric characteristics of ${\epsilon}_r<5.1,\;Q{\ge}1,000$. Residual fine closed pores could be reduced with control of sintering temperature and time. 3 point bending strength and chemical durability were evaluated to obtain feasibility for substrate material.

• 전자공학회논문지A
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• 제29A권9호
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• pp.46-55
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• 1992

본 논문에서는 다층유전체 구조를 갖는 VLSI interconnection line 에 대한 커페시턴스를 계산하기 위한 방법을 제안한다. 이 방법은 단일 유전체 구조에서 개발한 3차원 직접 적분방법을 확장한 것이다. 다층유전체에 의한 영향은 Green's function을 수정하는 대신에 경계조건을 추가함으로써 고려하였다. 여기서 사용한 경계조건은 line 표면에서는 전위에 대한 식을 사용하였고, 유전체 경계면ㅇ서는 전계에 대한 식을 사용하였다. 이 방법으로부터 얻어진 커패시턴스를 이용하여 다층유전체 구조에서의 interconnection line에 대한 RC 지연시간의 값을 구했다. 이때 사용한 interconnection 물질은 Al과 WSi-이다.

• E2M - 전기 전자와 첨단 소재
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• 제7권5호
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• pp.403-408
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• 1994

Dielectric and structural properties of $Ba_{1-x}$(Z $n_{1}$3/T $a_{2}$3/) $O_{3}$+1 mol% Mn $O_{2}$ (x=0, 0.01, 0.02, 0.03, 0.04) ceramics was investigated at microwave frequencies. With $Ba_{+2}$ shortage, the sinterability and the unloaded Q( $Q_{u}$) were much improved, and the ordering in B site and the lattice distortion was greatly enhanced and the structure approached the completely ordered structure. $Q_{u}$ was strongly correlated with these factors such as ordering ratio, lattice distortion and sinterability, and had the maximum value of 7500 at x=0.01. The dielectric constant was near 30 and the temperature coefficient of the resonant frequency was 2 ppm/.deg. C at x=0.01.1.1.1.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.190-193
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• 2003

Sm-doped lead zirconate titanate($Pb_{1.1}(Zr_{0.6}Ti_{0.4})O_3$; PZT) thin films on the Pt(111)/Ti/$SiO_2$/Si(100) substrates prepared by a sol-gel method. The effect on structural and electrical properties of PZT thin films measured according to the Sm content. Sm-doping altered significantly dielectric and ferroelectric properties. The remanent polarization and the coercive field decreased with the increasing Sm content. The dielectric constant and the dielectric loss of PZT thin films decreased with the increasing Sm content. At 100 kHz, the dielectric constant and the dielectric loss of. the 0.3 mol% of Sm-doped PZT thin film were 1200 and 0.12 respectively. The remanent polarization (2Pr) of the 0.3 mol% of Sm-doped PZT thin film was $52.13{\mu}C/cm^2$ and the coercive field was 94.01 kV/cm. The 0.3 mol% of Sm-doped PZT thin film showed an improved fatigue characteristic comparing to the undoped PZT thin film.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.117-120
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• 2004

The dielectric and piezoelectric properties of silver doped $Pb(Zr,Ti)O_3-Pb(Mn,W,Sb,Nb)O_3$ ceramics was examined. By varying the contents of silver(0.0, 0.4, 1.0 mol%), the effect of doped silver on PZT-PMWSN thin film was investigated at various sintering temperature(900, 1000, $1100^{\circ}C$). As increasing silver contents, the relative dielectric constant is increased and sinterbility is enhanced. At the specimen with 0.4 mol% Ag and sintered at $1100^{\circ}C$, electromechanical coupling factor(kp), mechanical quality factor(Qm), dielectric constant(${\varepsilon}r$) and dielectric loss were 0.502, 811, 991, 0.006, respectively. The results show that the PZT-PMWSN/Ag composites have enhanced piezoelectic and dielectric properties and processing condition is improved.

• 한국전기전자재료학회논문지
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• 제20권4호
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• pp.348-351
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• 2007

Recently, Nanotechnology becomes a major issue in most part of industries. Nanotechnology is expected to develop various application products due to nano material mired composites is improved physical and electrical properties compared to conventional composites materials. Dielectric and insulation materials need to develop and improve like other field about nanotechnology. In this paper, we reported dielectric dispersion by size(no filler, $1.2{\mu}m$, 500 nm, 10 nm), frequencies(60, 120, 1 kHz), and temperatures($30{\sim}170^{\circ}C$). Dielectric constant of composites materials with filler shows higher than composites materials without filler and increased depending on rising temperatures in low frequency region. It was the effect that nano-filler and impurities in composites contributed to electrical conductivity. And dielectric properties depending on temperatures shows to change in low frequency region dramatically We analyzed interfacial polarization in low frequency region($10^{-2}$ Hz) and oriented polarization in high frequency region($10^{-5{\sim}6}$ Hz) on composites materials.

• 한국세라믹학회지
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• 제50권1호
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• pp.87-91
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• 2013

The doping effect of Sn on the microstructure evolution and dielectric properties was studied in $CaCu_3Ti_{4-x}Sn_xO_{12}$ polycrystals. Samples were produced by a conventional solid-state reaction method. Sintering was carried out at $1115^{\circ}C$ for 2-16 h in air. The dielectric constant and loss were examined at room temperature over a frequency range between $10^2$ and $10^6$ Hz. The microstructure was found to evolve into three stages. Addition of $SnO_2$ led to an increase in density and advanced formation of abnormal grains. The formation of coarse grains with a reduced thickness of the boundary brought about an enhanced dielectric constant and a lower dielectric loss below ~1 kHz. EDS data showed the Cu-rich phase along the grain boundary, which should contribute to the improved dielectric constant according to the internal barrier layer capacitor model. After all, $SnO_2$ was an effective dopant to elevate the dielectric characteristics of $CaCu_3Ti_{4-x}Sn_xO_{12}$ polycrystals as a promoter for abnormal grain growth.

• 한국도로학회논문집
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• 제11권1호
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• pp.95-104
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• 2009

본 연구는 아스팔트 콘크리트의 유전율과 공극률의 상관성을 평가하기 위해 수행되었다. 이를 위해 다양한 범위 $(0%{\sim}20%)$의 공극률을 갖는 아스팔트 콘크리트 시편을 제작하였고, 저주파 유전율 측정법인 parallel plate법을 사용하여 아스팔트 콘크리트 시편의 유전율을 측정하였다. 아스팔트 콘크리트 시편의 경우 주파수가 증가함에 따라 유전율은 감소하는 경향을 나타내었고, 사용한 아스팔트 바인더의 종류에 따라 그 감소폭이 다르게 나타났다. 또한 공극률 $0%{\sim}20%$ 사이에서 공극률이 증가함에 따라 유전율 값은 선형적으로 감소하는 경향을 보였다. 더불어 아스팔트 콘크리트 시편의 유전율에 대한 온도 및 함수량 영향을 보정하여 유전율에 따른 공극률의 상관식을 제시하였다. 본 연구를 통해 제시된 아스팔트 콘크리트의 유전율과 공극률의 상관식은 현재 국내외에서 사용하고 있는 유전율을 활용한 비파괴 밀도 측정장비의 보정모델로 활용 가능하며, 향후 국내에서 개발하고자 하는 아스팔트 포장 비파괴 밀도 측정장비의 기본적인 알고리즘으로 활용이 가능할 것이다.

• Journal of Electrical Engineering and Technology
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• 제10권1호
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• pp.320-324
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• 2015

Mutual coupling between antenna elements of a linear microstrip patch antenna array positioned along the H-plane including the effect of edge reflections is investigated. Simple formulas are presented for the estimation of the grounded dielectric substrate size with minimum mutual coupling. The substrate sizes calculated by these formulas are in good agreement with those obtained by the full-wave simulation and experimental measurement. The substrate size with minimum mutual coupling is a function of the effective dielectric constant for surface waves and the distance between the antenna centers. The substrate size with minimum mutual coupling decreases as the effective dielectric constant for surface waves on a finite grounded dielectric substrate increases.

• 한국전기전자재료학회논문지
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• 제26권12호
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• pp.867-871
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• 2013

The Ti adhesion layers were deposited onto the glass substrate for transparent capacitors using $Bi_2Mg_{2/3}Nb_{4/3}O_7$ (BMNO) dielectric thin films. Graphene was transferred onto the Ti/glass substrate after growing onto the Ni/$SiO_2$/Si using rapid-thermal pulse CVD (RTPCVD). The BMNO dielectric thin films were investigated for the microstructure, dielectric and leakage properties in the case of capacitors with and without Ti adhesion layers. Leakage current and dielectric properties were strongly dependent on the Ti adhesion layers grown for graphene bottom electrode.