• Title/Summary/Keyword: Glass dielectric layer

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Microwave Absorbing Properties of Fiber Reinforced Composites with Sandwitch Structure (샌드위치 구조형 섬유강화 복합재료의 전파흡수특성)

  • Kim, Sang-Yeong;Kim, Sang-Su
    • Korean Journal of Materials Research
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    • v.12 no.6
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    • pp.442-446
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    • 2002
  • Design of microwave absorbers using high frequency properties of fiber reinforced composites are investigated. Two kinds of composite materials (glass and carbon) are used and their complex permittivity and permeability are measured by transmission/reflection technique using network analyzer. Low dielectric constant and nearly zero dielectric loss are determined in glass fiber composite. However, carbon fiber composites show the high dielectric constant and large conduction loss which is increased with anisotropy of fiber arrangement. It is, therefore, proposed that the glass and carbon fiber composites can be used as the impedance transformer (surface layer) and microwave reflector, respectively. By inserting the foam core or honeycomb core (which can be treated as an air layer) between glass and carbon fiber composites, microwave absorption above 10 dB (90% absorbance) in 4-12 GHz can be obtained. The proposed fiber composites laminates with sandwitch structure have high potential as lightweight and high strength microwave absorbers.

Discharge Characteristic of Surface Type FFL as LCD Backlighting according to Dielectric Layer (LCD 후면광원용 면방전형 FFL의 Dielectric Layer에 따른 방전 특성)

  • 임민수;정득영;윤성현;임기조;권순석
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.177-180
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    • 1999
  • In this paper, we studied Surface Discharge Type Flat Fluorescent Lamp(FFL) with High Luminance for LCD Backlighting. This lamp is Surface Discharge Type structure with a pair of Sodalime glass, insulator layer, phosphor layer, and Xe gas gap. There are two influences of Electric field on different dielectric thickness. The Electric field difference at the dielectric layer itself enhances minimum value of firing voltage and luminance uniformity. So, we measured the Electric filed at 0.5mm, 1mm gap length and discharge voltage for difference dielectric layer thickness. In experiment result, the thicker dielectric layer has higher firing voltage and lower current.

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Effect of Ti Adhesion Layer on the Electrical Properties of BMNO Capacitor Using Graphene Bottom Electrodes (그래핀 하부전극을 이용하여 BMNO 케페시터의 특성 향상을 위한 Ti Adhesion Layer의 효과)

  • Park, Byeong-Ju;Yoon, Soon-Gil
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.12
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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.

A Study on Development of Dielectric Layers for High-Temperature Electrostatic Chucks (고온용 정전기척의 유전층 개발에 관한 연구)

  • 방재철
    • Journal of the Microelectronics and Packaging Society
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    • v.8 no.3
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    • pp.31-36
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    • 2001
  • Dielectric material which is suitably designed for the application of the high-temperature electrostatic chucks(HTESCS) has been developed. Electrical resistivities and dielectric constants of the dielectric layer satisfy the demands for the proper operation of HTESC, and coefficient of thermal expansion(CTE) of the dielectric material matches well that of the bottom insulator so that it secures stable structure. In order to minimize particle contaminations, borosilicate glass(BSG) is selected as a bonding layer between dielectric layer and bottom insulator, and silver is used as a electrode. BSG is solidly bonded between upper dielectric and bottom insulator, and no diffusions or reactions are observed among silver electrode, dielectric, and glass layers. The chucking characteristics of the fabricated HTESC are found to be superior to those of the commercialized one.

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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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The Study of Dielectric Layer Design for Luminance Efficiency of White Organic Light Emitting Device (백색 OLED의 발광효율 향상을 위한 Dielectric Layer 설계에 관한 연구)

  • Kim, Sang-Gi;Jin, En Mei;Gu, Hal-Bon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.10
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    • pp.850-853
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    • 2009
  • We have optimized the device structure by using the dielectric layer such as anti-reflection thin film to improve the emitting efficiency of white organic light emitting device (WOLED). Basically, dielectric layer with anti-reflection characteristics can enhance the emitting efficiency of WOLED by compensating the refractive index of organic layer, ITO, and Glass. Here, WOLED was designed and optimized by Macleod simulator. The refractive index of 1.74 was calculated for Dielectric layer and was selected as $TiO_2$. The optimal thicknesses of $TiO_2$ and ITO were 119.3 and 166.6 nm, respectively, at the wavelength of 600 nm. The transmittance of ITO was measured with the thickness variation of dielectric layer and ITO in Organic layer/ITO/Dielectric layer structure. The transmittance of ITO was 95.17% and thicknesses of $TiO_2$ and ITO were 119.3 and 166.6 nm, respectively. This result, calculated and measured values were coincided.

Dependence of Xe Plasma Flat Fluorescent Lamp On the Electrode Gap and Dielectric Layer Thickness

  • Kang, Jong-Hyun;Lee, Yang-Kyu;Heo, Sung-Taek;Oh, Myung-Hoon;Lee, Dong-Gu
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1519-1521
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    • 2007
  • In this work, a coplanar-type plasma flat fluorescent lamp having cross type of electrode was fabricated by screen printing and sealing technique. Cross type of electrode with a dielectric layer were screen-printed on a rear glass plate, and then fired at $550^{\circ}C$. Phosphor was printed on and fired at $450^{\circ}C$. Finally, the lamp was sealed by frit glass at $450^{\circ}C$. The lamp of cross electrode type was studied depending on the electrode gap and the thickness of dielectric layer.

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Research on Glass Dielectric Capacitive Coupling Wireless Power Transfer Using Transparent Electrode (투명 전극을 적용한 유리 유전체 커패시티브 커플링 무선 전력 전송에 관한 연구)

  • Yi, Kang-Hyun
    • The Transactions of the Korean Institute of Power Electronics
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    • v.23 no.4
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    • pp.286-289
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    • 2018
  • This paper tests the feasibility of using the transparent electrode as the electrode of the capacitor in order to use the vehicle glass of the electric vehicle for a capacitive coupling wireless transfer (CCWPT). Large coupling capacitance can be obtained due to large area and high permittivity using the glasses of an electric vehicle. However, if an electrode is formed on a metal such as copper, then a view cannot be guaranteed and a transparent electrode can pose a solution. Therefore, the coupling capacitor is implemented by forming a glass dielectric with an ITO transparent electrode on one side through a semiconductor deposition process. The loss of the coupling capacitor is investigated, and a 200 W CCWPT prototype is fabricated and tested for its characteristics and power transfer.

The Effect of Dielectric Thickness and Barrier Rib Height on Addressing Time of Coplanar AC PDP (AC PDP의 유전체 두께와 격벽 높이에 따른 Addressing Time)

  • 신중홍;박정후
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.12
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    • pp.1065-1069
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    • 2002
  • The addressing time should be reduced by modifying cell structure and/or driving method in order to replace the dual scan system by single scan and increase the luminance in large ac plasma display panel(PDP). In this paper, the effects of the addressing time was decreased with decreasing thickness of dielectric layer on the front glass and thickness of white dielectric layer on the rear glass. the decreasing rate were 160ns/10$\mu\textrm{m}$ and 270ns/10$\mu\textrm{m}$, respectively Also in case of decreasing the height of barrier rib, addressing time was decreased at the rate of Sons/10$\mu\textrm{m}$.

Effects of Additives on Dielectric Properties and Microstructure of MLCC X7R Composition (첨가물의 형태가 MLCC X7R 조성의 유전 특성 및 미세구조에 미치는 영향)

  • Moon, Hwan;Kim, Min-Kee;Jeon, Hyun-Pyo;Ahn, Jae-Pyoung;Yoon, Jung-Rag;Chung, Tae-Serk
    • Journal of the Korean Ceramic Society
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    • v.40 no.7
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    • pp.644-651
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    • 2003
  • Effects of additives on electrical properties and microstructure of MLCC X7R dielectrics have been investigated. The additives of glass frit or oxide form were added in the same main composition by the different powder processing conditions. As a result of the dielectric property and microstructure analysis, the composition having the glass layer with dopant concentration gradient showed the excellent dielectric properties. The MLCCs were fabricated with the excellent composition and all dielectric properties satisfied the X7R requirements.