• 제목/요약/키워드: vacuum process

검색결과 2,247건 처리시간 0.031초

High vacuum packaging and vacuum evaluation for field emission display

  • Jung, S.J.;Woo, K.J.;Lee, N.Y.;Ahn, S.;Moon, G.J.;Kim, K.S.;Kim, M.S.
    • Journal of Korean Vacuum Science & Technology
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    • 제3권1호
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    • pp.95-97
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    • 1999
  • A 3.12" FED panel was packaged successfully using the anode plate on which phosphors and black matrix were coated and cathode plate containing emitter arrays. The vacuum level of the panel was investigated during panel evacuation, tip-off and getter activation process. The packaged panel exhibited vacuum level below 2${\times}$10-6 Torr. Similar experiments were carried out for 10" panel made of bare plates. In addition, the vacuum level of two panels was compared continuously after tip off process; one with the getter and the other without it.

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연료탱크 진공주유절차 개발 (Development of Vacuum Refueling Process for Fuel Tank)

  • 박정배;민성기;이세영;김영신;이종철;장기원
    • 한국추진공학회지
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    • 제15권3호
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    • pp.80-85
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    • 2011
  • 연료탱크 내부에 존재하는 공기는 저장 중 연료의 산화를 유발하고, 연료 이송성능을 저하시킬 수 있다. 따라서 항공기 연료탱크의 주유절차를 개선하기 위하여 연료탱크 내부에 존재하는 공기를 줄이는 방안으로 진공주유방식을 제안하였다. 본 논문에서는 진공주유 절차를 수립하여 실제 시험을 수행해 보았고, 이를 통해 진공 주유 중 발생하는 현상을 관찰할 수 있었다. 또한 탱크 내부의 기포 및 주유시간 절감을 위하여 다른 개선된 방안을 제안하였다.

Simulations of Effects of Variable Conductance Throttle Valve on the Characteristics of High Vacuum System

  • Kim, Hyung-Taek;Cho, Han-Ho
    • International Journal of Internet, Broadcasting and Communication
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    • 제7권2호
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    • pp.28-35
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    • 2015
  • Thin film electronic devices which brought the current mobile environment could be fabricated only under the high quality vacuum conditions provided by high vacuum systems. Especially for the development of advanced thin film devices, constant high quality vacuum as the deposition pressure is definitely needed. For this purpose, the variable conductance throttle valves were employed to the high vacuum system. In this study, the effects of throttle valve applications on vacuum characteristics were simulated to obtain the optimum design modelling of variable conductance of high vacuum system. Commercial simulator of vacuum system, $VacSim^{(multi)}$, was used on this investigation. Reliability of employed simulator was verified by the simulation of the commercially available models of high vacuum system. Simulated vacuum characteristics of the proposed modelling were agreed with the observed experimental behaviour of real systems. Pressure limit valve and normally on-off control valve were schematized as the modelling of throttle valve for the constant process-pressure of below $10^{-3}torr$. Simulation results were plotted as pump down curve of chamber, variable valve conductance and conductance logic of throttle valve. Simulated behaviors showed the applications of throttle valve sustained the process-pressure constantly, stably, and reliably.

진공챔버 내 프리트 이용 진공유리 봉지공정 최적화에 관한 연구 (A Study on Optimization of Vacuum Glazing Encapsulating Process using Frit inside a Vacuum Chamber)

  • 박상준;이영림
    • 한국산학기술학회논문지
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    • 제14권2호
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    • pp.567-572
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    • 2013
  • 냉난방을 사용하는 가정에서는 대부분 창문을 통해 열손실이 이루어지고 있는데 이를 방지하기 위해 Low-E 유리, 복층유리 또는 진공유리가 사용되고 있다. 본 논문에서는 진공유리 제작공정의 최종공정인 봉지공정에 대한 연구가 수행되었는데 기존 상압 접합이 아닌 진공챔버 내 접합이 고려되었다. 봉지과정의 효율성을 위해 진공챔버 내에서 히터온도에 따른 프리트 용융온도 및 접합시간을 최적화하였고 열응력으로 인한 유리 파손을 방지하기 위해 유리 예열온도를 최적화하였다. 이러한 결과를 바탕으로 성공적으로 진공유리를 제작하였고 측정된 열관류율은 약 $5.7W/m^2K$로 진공유리 내부압력은 약 $10^{-2}$ torr로 판명되었다.

Effect of Alternating Vacuum and Release Process on Drying Characteristics of Log Cross Section during Radio Frequency Drying

  • Xie, Dan;Lee, Nam-Ho;Chang, Yoon-Seong;Yeo, Hwanmyeong
    • Journal of the Korean Wood Science and Technology
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    • 제41권5호
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    • pp.456-465
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    • 2013
  • Log cross sections of yellow poplar were dried in a radio frequency vacuum (RFV) dryer under alternating vacuum and release (AVR) process. The average moisture content (MC), temperature and vapor pressure at the volumetric center were monitored as functions of time. Three different log thicknesses (33, 60 and 75mm) were tested. The results show that the AVR process caused an increase in the drying rate when the moisture content was above fiber saturation point (FSP, about 30% MC) but that it had an inverse effect on the drying rate when the MC was below FSP. The effect of the AVR process on the drying rate decreased, and the severity of heart checks increased, with the increase in the thickness of the specimens.

Prohibition of Boundary Image Sticking in AC Plasma Display Panel Using Vacuum Sealing Method

  • Tae, Heung-Sik;Park, Choon-Sang;Kwon, Young-Kuk;Heo, Eun-Gi;Lee, Byung-Hak
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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    • pp.1688-1691
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    • 2007
  • This paper shows that the boundary image sticking can be prohibited completely by using the vacuum sealing process, which means that the residual impurities such as nitrogen or oxygen can be a critical factor inducing the boundary image sticking. The production of boundary image sticking was checked in the test panel fabricated by the $N_2$ or $O_2$ flow during the vacuum sealing process. As a result, the boundary image sticking did not appear in the case of $N_2flow$, whereas the boundary image sticking was observed in the case of $O_2$ flow even though the test panel was fabricated by the vacuum sealing process.

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진공 열 증착 기반의 정공수송층 적용을 통한 페로브스카이트 태양전지 (Perovskite Solar Cells through Application of Hole Transporting Layers based on Vacuum Thermal Evaporation)

  • 김혜승;송명훈
    • Current Photovoltaic Research
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    • 제10권1호
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    • pp.23-27
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    • 2022
  • In this study, we investigate organic-inorganic halide perovskite solar cells with a vacuum thermal evaporated hole transporting layer (NPB/MoO3-x). By replacing solution process based Spiro-MeOTAD with vacuum thermal evaporation based NPB/MoO3-x, a thin hole transporting layer was implemented. In addition, parasitic absorption that may occur during the doping process was eliminated by excluding solution process doping. In a solar cell with a thin vacuum thermal evaporated hole transporting layer, the short-circuit current density (Jsc) increased to 23.93 mA/cm2, resulting in the highest power converstion efficiency (PCE) at 18.76%. Considering these results, it is essential to control the thickness of hole transporting layer located at the top in solar cell configuration.

화학기상증착법(CVD)을 이용한 진공 박막 공정기술 (Thin Film Vacuum Process Technology via Chemical Vapor Deposition Methods)

  • 홍완식
    • 진공이야기
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    • 제1권3호
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    • pp.9-13
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    • 2014
  • Vacuum growth of thin films via chemical vapor deposition (CVD) methods has been extensively used in modern semiconductor and flat panel display industries. The CVD processes have a wide range of variation and are categorized according to their working conditions, power sources, precursor materials, and so forth. Basic components and process steps common to all CVD branches are discussed. In addition, characteristics and applications of two major CVD techniques - LPCVD and PECVD - are reviewed briefly.

냉장 또는 동결우육에 있어서 저장기간과 재냉장이 연도에 미치는 영향 (Effects of Storage Period and Rechilling Process on Tenderness of Chilled or Frozen Beef)

  • 김미숙;문윤희
    • 한국축산식품학회지
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    • 제18권3호
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    • pp.216-223
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    • 1998
  • This study was conducted to investigate the effects of the tenderness for the vacuum chilled, the air-frozen or the rechilled Holstein beef loin. The vacuum packaged beef was stored at 1$^{\circ}C$ and the air-packaged beef was stored at -20$^{\circ}C$ for 60 days. The rechilled beef was restored for 3 days at 1$^{\circ}C$ by using the vacuum chilled or the air-frozen beef. Hardness and chewiness of the vacuum chilled beef were better than those of the air-frozen beef. Hardness and chewiness were improved significantly(p<0.05) after the 40 days storage for the vacuum chilled beef, but there was no significant improvement for the air-frozen beef during the 60 days storage. By the rechilling process, tenderness and myofibrillar fragmentation index of the vacuum chilled and air-frozen beef improved. Especially those were improved significantly(p<0.05) in the vacuum chilled beef after the 20 days storage, and in the air-frozen beef after the 40 and 60 days storage.

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