• Title/Summary/Keyword: Dielectric Materials

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Fabrication and Characterization of Dielectric Materials of Front and Back Panel for PDP

  • Chang, Myeong-Soo;Pae, Bom-Jin;Lee, Yoon-Kwan;Ryu, Byung-Gil;Park, Myung-Ho
    • Journal of Information Display
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    • v.2 no.3
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    • pp.39-43
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    • 2001
  • The glass compositions of $PbO-SiO_2-B_2O_3$ system and $P_2O_5-PbO-ZnO$ system for the transparent dielectric materials for front panel and $P_2O_5$-ZnO-BaO and $SiO_2-ZnO-B_2O_3$ for the reflective dielectric materials for back panel of PDP (Plasma Display Panel) were investigated. As a result, transparent dielectric materials for front panel showed good dielectric properties, high transparency, and proper thermal expansion matching to soda lime glass substrate. And the reflective dielectric layers for back panel were prepared from two series of parent glass and oxide filler. It was found that these glassceramics are useful materials for dielectric layers in PDP device, as they have similar thermal expansion to soda-lime glass plate, high reflectance, and low sintering temperature. In particular, the addition of $BPO_4$ and $TiO_2$ as fillers to $SiO_2-ZnO-B_2O_3$ system is considered to be the most effective for acquiring good properties of lower dielectric layer for PDP device.

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Recent Progress in Dielectric-Based Ultrafast Charging/Discharging Devices (유전체를 활용한 초고속 에너지 충/방전 소자 기술)

  • Choi, Hyunsu;Ryu, Jungho;Yoon, Woon-Ha;Hwang, Geon-Tae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.35 no.4
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    • pp.322-332
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    • 2022
  • Energy storage capacitors based on dielectric ceramics with superior polarization properties and dielectric constant can provide much higher output power density due to their very fast energy charging/discharging rates, which are particularly suitable for operating pulsed-power devices. For an outstanding energy storage performance of dielectric capacitor, a large recoverable energy density could be derived by introducing a slim polarization-electric field hysteresis loop into dielectric materials by various technical approaches. Many research teams have explored various dielectric capacitor technologies to demonstrate high output power density and ultrafast charging/discharging behavior. This article reviews the recent research progress in high-performance dielectric capacitors for pulsed-power electronic applications.

High Energy Density Dielectric Ceramics Capacitors by Aerosol Deposition (상온 분사 공정을 이용하여 제조한 고에너지 밀도 세라믹 유전체 커패시터)

  • Hyunseok Song;Geon Lee;Jiwon Ye;Ji Yun Jung;Dae-Yong Jeong;Jungho Ryu
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.37 no.2
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    • pp.119-132
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    • 2024
  • Dielectric ceramic capacitors present high output power density due to the fast energy charge and discharge nature of dielectric polarization. By forming dense ceramic films with nano-grains through the Aerosol Deposition (AD) process, dielectric ceramic capacitors can have high dielectric breakdown strength, high energy storage density, and leading to high power density. Dielectric capacitors fabricated by AD process are expected to meet the increasing demand in applications that require not only high energy density but also high power output in a short time. This article reviews the recent progress on the dielectric ceramic capacitors with improved energy storage properties through AD process, including energy storage capacitors based on both leadbased and lead-free dielectric ceramics.

Gate dielectric based on organic-inorganic hybrid polymer in organic thin-film transistors

  • Lee, Seong-Hui;Jeong, Sun-Ho;Moon, Joo-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.727-729
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    • 2007
  • Inorganic-organic hybrid polymer provides various advantages including low-temperature process, high dielectric constant and direct photo-patterning. The hybrid dielectric was synthesized by the sol-gel process in which an acid-catalyzed solution of Si alkoxide and Zr alkoxide was used as a precursor. The electrical performance of transistors with hybrid dielectric was investigated.

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Dielectric sensor for cure monitoring of composite materials (복합재료 경화도 측정을 위한 유전 센서)

  • 김학성;권재욱;김진국;이대길;최진경;김일영
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.05a
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    • pp.219-223
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    • 2001
  • The on-line cure monitoring during the cure process of composite materials is important for better quality and productivity. The dielectric sensor for cure monitoring consists of base film and electrodes. Because the characteristic of dielectric sensor for the on-line cure monitoring is dependent on the base material, width and number of electrode, etc, the dielectric sensor should be standardized. And the selection of base film material of sensor is very important. In order to prevent the measuring errors generated from the increase of environmental temperature, the base film material should have stable dielectric constant with respect to environmental temperature. In this study, the newly developed dielectric sensor for cure monitoring was designed and the dissipation factor which is function of degree of cure was measured using the sensor. The relationship between the dissipation factor and degree of cure with respect to environmental temperature was investigated.

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Effects of Crystal Structure on Microwave Dielectric Properties of Ceramics

  • Kim, Eung-Soo;Jeon, Chang-Jun;Kim, Sung-Joo;Kim, Su-Jung
    • Journal of the Korean Ceramic Society
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    • v.45 no.5
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    • pp.251-255
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    • 2008
  • Microwave dielectric properties of $MgTiO_3,\;MgWO_4,\;MgNb_2O_6$, and $MgTa_2O_6$ were investigated based on the structural characteristics. The dielectric constant (K) was dependent on the dielectric polarizabilities of the specimens, and the deviation of the observed dielectric polarizabilities (${\alpha}_{obs.}$) from the theoretical dielectric polarizabilities (${\alpha}_{theo.}$) were decreased with increasing of Mg-site bond valence. Quality factors (Qf) were affected by the sharing type of $MgO_6$ and $BO_6$ octahedra. Temperature coefficient of resonant frequency (TCF) was decreased with increasing of average octahedral distortion.

The Influence of $Ta_2O_{5}$ Addition on Dielectric Characteristics of Zirconium Titanate Ceramics (Zirconium Titanate 세라믹 유전체에서 $Ta_2O_{5}$ 첨가가 유전특성에 미치는 영향)

  • 이석진;이창화;이상석;최태구
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1992.05a
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    • pp.129-132
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    • 1992
  • Rutile was among the first dielectric materials used. However, rutile exhibits a very high temperature coefficient of capacitance (about -750[ppm/$^{\circ}C$]) which resticts its practical application. Since this first use of titania, other materials have also been studied with the object of decreasing the temperature dependence whilst retaining favorable dielectric loss, Q, and relative permittivity. The temperature coefficient of temperature compensation capacitor is +100~750[ppm/$^{\circ}C$], dielectric constant 10~150. Low loss ceramics with dielectric constants in the 10~150 range also found application. Recently, their applications are extended in EMI filter and dielectric materials for microwave. There temperature coefficient of dielectric materials approaches 0[ppm/$^{\circ}C$]. The dielectric preperties of zirconia titanate ceramics prepared by addition of $Ta_2O_{5}$ were investigated.

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Dielectric Breakdown Behavior of Anodic Oxide Films Formed on Pure Aluminum in Sulfuric Acid and Oxalic Acid Electrolytes

  • Hien Van Pham;Duyoung Kwon;Juseok Kim;Sungmo Moon
    • Journal of the Korean institute of surface engineering
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    • v.56 no.3
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    • pp.169-179
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    • 2023
  • This work studies dielectric breakdown behavior of AAO (anodic aluminum oxide) films formed on pure aluminum at a constant current density in 5 ~ 20 vol.% sulfuric acid (SA) and 2 ~ 8 wt.% oxalic acid (OA) solutions. It was observed that dielectric breakdown voltage of AAO film with the same thickness increased with increasing concentration of both SA and OA solutions up to 15 vol.% and 6 wt.%, respectively, above which it decreased slightly. The dielectric breakdown resistance of the OA films appeared to be superior to that of SA films. After dielectric breakdown test, cracks and a hole were observed. The crack length increased with increasing SA film thickness but it did not increase with increasing OA film thickness. To explain the reason why shorter cracks formed on the OA films than the SA films after dielectric breakdown test, the generation of tensile stresses at the oxide/metal interface was discussed in relation to porosity of AAO films obtained from cross-sectional morphologies.

Interaction Between Transparent Dielectric and Bus Electrode for Heating Profile in PDP

  • Lee, Sang-Wook;Kim, Dong-Sun;Park, Mi-Kyung;Hwang, Seong-Jin;Kim, Hyung-Sun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.864-866
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    • 2007
  • In PDP, bus electrode should have low resistance for high efficiency. The transparent dielectric affects the shape change of bus electrode during the firing. These are related with the electrical property of the electrode. In this study, the shape of electrode was controlled by firing schedules of the transparent dielectric and the bus electrode.

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