• Title/Summary/Keyword: glass structure

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Injection molding and structure analysis for design of glass insert injection mold (유리인서트 사출금형 설계를 위한 사출성형 및 구조해석)

  • Moon, Young-Bae;Go, Bo-Sun;Jeong, Yeong-Deug
    • Design & Manufacturing
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    • v.2 no.3
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    • pp.6-9
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    • 2008
  • This paper describes the process of structure analysis and injection molding analysis to manufacture the forming injection dies for huge glass insert. Factors such as filling time, filling pressure, material temperature, shrinkage, warpage were investigated by using the analysis software, Moldflow. Runner system and cavity structure were designed and manufactured through the results of deformation analysis data for glass insert. Filling time and filling pressure were analyzed in 3.756sec and 43.37MPa.

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Discharge Characteristics of AC PDP Cell as a parameter of PDP Cell structure (표면방전형 PDP Cell의 상,하판 구조에 따른 방전특성)

  • Park, Young-Chan;Chi, Sung-Won;Kim, Gyu-Seup;Cho, Jung-Soo;Park, Chung-Hoo
    • Proceedings of the KIEE Conference
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    • 1997.07e
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    • pp.1749-1751
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    • 1997
  • AC PDP with surface micro discharge has a structure that all discharge electrodes are arranged on the front glass panel, and the rear glass panel merely serves as a cover glass to form the micro discharge space. The relationships between the dischage voltage and the structure among such as electrode width, distance between electrodes, discharge space gap, and dielectric layer width are investigated.

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A study on the breakdown characteristics of power p-n junction device using field limiting ring and side insulator wall (전계제한테와 측면 유리 절연막 사용한 전력용 p-n 접합 소자의 항복 특성 연구)

  • 허창수;추은상
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.3
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    • pp.386-392
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    • 1996
  • Zinc-Borosilicate is used as a side insulator wall to make high breakdown voltage with one Field Limiting Ring in a power p-n junction device in simulation. It is known that surface charge density can be yield at the interface of Zinc-Borosilicate glass / silicon system. When the glass is used as a side insulator wall, surface charge varied potential distribution and breakdown voltage is improved 1090 V under the same structure.The breakdown voltage under varying the surface charge density has a limit value. When the epitaxial thickness is varied, the position of FLR doesn't influence to the breakdown characteristic not only under non punch-through structure but also under punch-through structure. (author). 7 refs., 12 figs., 2 tabs.

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Fabrication of Bulk Metallic Glass Composites by Mechanical Milling with Subsequent Spark Plasma Sintering Process (기계적 밀링 및 방전 플라즈마 소결 공정을 이용한 벌크 비정질 복합재의 제조)

  • Lee, Jin-Kyu;Kim, Taek-Soo;Kim, Jeong-Gon
    • Journal of Powder Materials
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    • v.14 no.3 s.62
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    • pp.197-201
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    • 2007
  • Bulk metallic glass (BMG) composite was fabricated by consolidation of milled metallic glass composite powders. The metallic glass composite powder was synthesized by a controlled milling process using the Cu-based metallic glass powder blended with 30 vol% Zr-based metallic glass powders. The milled composite powders showed a layered structure with three metallic phases, which is formed as a result of mechanical milling. By spark plasma sintering of milled metallic glass powders in the supercooled liquid region, a fully dense BMG composite was successfully synthesized.

Preparation of Carbon-Containing Silica Glass by Heat Treatment of Ormosil (세라믹/고분자 복합체의 열처리에 의한 탄소 함유 실리카 유리의 제조)

  • 김구대;이동아;박지애;문지웅
    • Journal of the Korean Ceramic Society
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    • v.36 no.5
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    • pp.459-464
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    • 1999
  • A carbon-containing silica glass was prepared from orgaincally modified silicate(Ormosil) by heat treatment in N2 atmosphere after the ormosil was synthesized using sol-gel method. The Ormosil was fabricated from the TEOS as the inorganic component and the PDMS as the organic component. The Ormosil changed to balck-coloured glass by carbon decomposed from the PDMS when the Ormosil was heated to 450$^{\circ}C$ 20hrs. A dense silicon oxycarbide glass with 2.08 g/cm3 was obtained by heating the Ormosil at 1050$^{\circ}C$ 10hrs. The microstructure of the carbon-containing silica glass was observed by SEM and the SiOxC4-x structure was confirmed by XPS measurement. The densification of the glass was studied by measurements of specific surface area linear shrinkage and geometric density.

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Study on the Aspheric Glass Lens Forming Simulation in the Progressive GMP process (순차이송 GMP 공정에서의 비구면 유리렌즈 성형 해석에 관한 연구)

  • Chang, S.H.;Gang, J.J.;Shin, K.H.;Jung, W.C.;Heo, Y.M.;Jung, T.S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.05a
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    • pp.539-542
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    • 2008
  • Recently, GMP(Glass Molding Press) process is mainly used to produce aspheric glass lenses. Because glass lens is heated at high temperature above Ty (yielding point) for forming glass, the quality of aspheric glass lens is deteriorated by residual stresses which are generated in a aspheric glass lens after forming. Before this study, as a fundamental study to develop forming conditions for progressive GMP process, compression, strain relaxation and thermal conductivity tests were carried out to obtain the visco-rigid plastic, the visco-elastic and thermal properties of K-PBK40 which is newly developed and applied for precision molding glass material, In this study, using the experimental results we obtained, a glass lens forming simulation in progressive GMP process was carried out and we could forecast the shape of deformed glass lenses and residual stresses contribution in the structure of deformed glass lenses after forming.

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Microstructure and Thermal Insulation Properties of Ultra-Thin Thermal Insulating Substrate Containing 2-D Porous Layer (2차원 기공층을 포함하는 초박형 단열기판의 미세구조 및 단열 특성)

  • Yoo, Chang Min;Lee, Chang Hyun;Shin, Hyo Soon;Yeo, Dong Hun;Kim, Sung Hoon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.30 no.11
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    • pp.683-687
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    • 2017
  • We investigated the structure of an ultra-thin insulating board with low thermal conductivity along z-axis, which was based on the idea of void layers created during the glass infiltration process for the zero-shrinkage low-temperature co-fired ceramic (LTCC) technology. An alumina and four glass powders were chosen and prepared as green sheets by the tape casting method. After comparison of the four glass powders, bismuth glass was selected for the experiment. Since there is no notable reactivity between alumina and bismuth glass, alumina was selected as the supporting additive in glass layers. With 2.5 vol% of alumina powder, glass green sheets were prepared and stacked alternately with alumina green sheet to form the 'alumina/glass (including alumina additive)/alumina' structure. The stacked green sheets were sintered into an insulating substrate. Scanning electron microscopy revealed that the additive alumina formed supporting bridges in void layers. The depth and number of the stacking layers were varied to examine the insulating property. The lowest thermal conductivity obtained was 0.23 W/mK with a $500-{\mu}m-thick$ substrate.

Compression Molding of Diffractive-Aspheric Lenses Using Chalcogenide Glasses (칼코겐유리를 활용한 회절비구면렌즈 압축성형)

  • Kim, Ji-Kwan;Choi, Young-Soo;Ahn, Jun-Hyung;Son, Byeong-Rea;Hwang, Young-Kug
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.6
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    • pp.43-48
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    • 2020
  • This study explores the compression molding of diffractive-aspheric lenses using GeSbSe chalcogenide glasses. A mold core with diffractive structure was prepared and a chalcogenide glass lens was molded at various temperatures using the corresponding core. The effect of molding temperature on the transcription characteristics of diffractive structure was examined, by measuring and comparing the diffractive structure between the mold core and the molded chalcogenide glass lens using a microscope and a white light interferometer. In addition, the applicability of the molded lens for thermal imaging was evaluated, by measuring the form error.

A study on the Structure of (62-x)CaO·38Al2O3 ·xBaO Glasses by Molecular Dynamics Simulation (분자동력학법에 의한(62-x)CaO·38Al2O3 ·xBaO 유리의 구조 분석)

  • Lee, Seong-Joo;Kang, Eun-Tne
    • Journal of the Korean Ceramic Society
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    • v.44 no.3 s.298
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    • pp.175-181
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    • 2007
  • Molecular dynamics simulation (MD) of $(62-x)CaO{\cdot}38Al_{2}O_{3}{\cdot}xBaO$ glasses has been carried out using empirical potentials with the covalent term. The simulations closely reproduce the total neutron correlation functions of glass with 5 mol% BaO and physical properties of these glasses such as elastic constants. For these glasses, aluminum is tetrahedrally coordinated by oxygen, but there is a part of five-fold and six-fold coordination of aluminum. There are no major changes to the mid-range structure of glass, as barium is substituted for calcium. To predict the barium coordination number, we have used the bond valence (BV) theory and also compared the results of simulation with Bond valence. The coordination number for oxygen around barium atoms is close to 8 and the average distance of barium and oxygen is nearly 2.80 A. The viscosity of these glasses increases with the content of barium oxide substituted for calcium oxide.

Design of Aircraft Internal On-glass Antennas (항공기용 내장형 온-글래스 안테나 설계)

  • Kang, Woo-Joon;Choo, Ho-Sung;KIim, Young-Gi;Kang, Ho-Won
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.12
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    • pp.65-71
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    • 2009
  • In this paper, we propose an aircraft on-glass antenna for FM radio reception. To obtain broad matching bandwidth, we employed a multiple loop as the basic antenna structure, and the shape of the loops mimics the frame of a window in order to ensure pilots' field of view as large as possible. The detailed design parameters of the multi-loop structure were determined using a Pareto genetic algorithm with a full wave EM simulation tool. The optimized on-glass antenna was built and installed on a Korean utility helicopter (KUH) The measurement results showed a half power matching bandwidth of about 63.3 %, average vertical bore-sight gain of about -12.98 dBi in the FM band.