• Title/Summary/Keyword: Vacuum

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Vacuum Sealing Technology of the Flat Panel Display by using the Frit Glass Heatable in Vacuum (진공에서 소성 가능한 프릿을 이용한 평판디스플레이 진공실장기술)

  • Kwon, Sang Jik;Yoo, In Sang
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.3
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    • pp.181-185
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    • 2016
  • One of the important issues for fabricating the microelectronic display devices such as FED, PDP, and VFD is to obtain a high vacuum level inside the panel. In addition, sustaining the initial high vacuum level permanently is also very important. In the conventional packing technology using a tabulation method, it is not possible to obtain a satisfiable vacuum level for a proper operation. In case of FED, the poor vacuum level results in the increase of operating voltage for electron emission from field emitter tips and an arcing problem, resultantly shortening a life time. Furthermore, the reduction of a sealing process time in the PDP production is very important in respect of commercial product. The most probable method for obtaining the initial high vacuum level inside the space with such a miniature and complex geometry is a vacuum in-line sealing which seals two glass plates within a high vacuum chamber. The critical solution for the vacuum sealing is to develop a frit glass to avoid the bubbling or crack problems during the sealing process at high temperature of about $400^{\circ}C$ under the vacuum environment. In this study, the suitable frit power was developed using a mixture of vitreous and crystalline type frit powders, and a vacuum sealed CNT FED with 2 inch diagonal size was fabricated and successfully operated.

Inter-comparison between ultrasonic interferometer manometer and medium vacuum standards by static expansion method (초음파간섭 수은주압력계와 정적법 중진공 국가표준기 상호비교)

  • Hong S. S.;Lim I. T.;Shin Y. H.;Chung K. H.
    • Journal of the Korean Vacuum Society
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    • v.14 no.3
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    • pp.103-109
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    • 2005
  • A new medium vacuum primary standard using the static expansion method was developed in KRISS. In order to evaluate the performance of the equipment, we compared the medium vacuum standard with an ultrasonic interferometer manometer using two capacitance diaphragm gauges, the measuring ranges of which were 133 Pa and 1,333 Pa respectively. The result, Error normalized values, showed that the two standards are coincident each other within the range of combined uncertainty at calibrated pressure of $3pa\;\sim\;100pa$.

Numerical Analysis on Effects of Horizontal Drain Arrangement of Vacuum Consolidation (수평배수재 배열의 진공압밀효과에 대한 수치해석)

  • Park, Byung-Soo;Jeong, Gil-Soo;Lee, Jong-Ho;Yoo, Nam-Jae
    • Journal of Industrial Technology
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    • v.23 no.A
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    • pp.109-118
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    • 2003
  • This paper is results of numerical works of investigating effects of horizontal drain arrangements on vacuum consolidation. Extensive numerical analyses were carried out to find the appropriate arrangements of horizontal drain of vacuum consolidation. Commercially available program of CRISP, well known to be good to modelling the behavior of clay material, was used Cam-clay model, based on the Critical State of Soil Mechanics(CSSM), was used to simulate the geotechnical engineering behavior of clay. Model test results carried out previously in the laboratory were compared with numerically estimated results and it was found that results about consolidational settlement with times were in good agreements. Based on this confirmation, parametric numerical study was performed to investigate effects of horizontal drain arrangements on vacuum consolidation with changing the vertical and horizontal spacings between drains for the given soil properties and vacuum. The effect of distance of drain located in top layer from the surface of the ground on the settlement due to vacuum was also investigated. As a results of numerical analyses, appropriate arrangements of horizontal drain to maximize the consolidation settlement due to vacuum were found. The mechanism of vacuum consolidation about the vacuum pressures being transferred to the effective stresses around drains was also evaluated.

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Optimal Design of an Exhaust System of a Vacuum-Compatible Air Bearing (진공용 공기베어링 배기시스템의 최적설계)

  • Khim, Gyung-Ho;Park, Chun-Hong;Lee, Hu-Sang;Kim, Seung-Woo
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.6
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    • pp.86-95
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    • 2007
  • This paper presents the optimal design of an exhaust system of a vacuum-compatible air bearing using a genetic algorithm. To use the air bearings in vacuum conditions, the differential exhaust method is adopted to minimize the air leakage, which prevents air from leaking into a vacuum chamber by recovering air through several successive seal stages in advance. Therefore, the design of the differential exhaust system is very important because several design parameters such as the number of seals, diameter and length of an exhaust tube, pumping speed and ultimate pressure of a vacuum pump, seal length and gap(bearing clearance) influence on the air leakage, that is, chamber's degree of vacuum. In this paper, we used a genetic algorithm to optimize the design parameters of the exhaust system of a vacuum-compatible air bearing under the several constraint conditions. The results indicate that chamber's degree of vacuum after optimization improved dramatically compared to the initial design, and that the distribution of the spatial design parameters, such as exhaust tube diameter and seal length, was well achieved, and that technical limit of the pumping speed was well determined.

Oxidative Etching of Imprinted Nanopatterns by Combination of Vacuum Annealing and Plasma Treatment

  • Park, Dae Keun;Kang, Aeyeon;Jeong, Mira;Lee, Jae-Jong;Yun, Wan Soo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.251.1-251.1
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    • 2013
  • Combination of oxidative vacuum annealing and oxygen plasma treatment can serve as a simple and efficient method of line-width modification of imprinted nanopatterns. Since the vacuum annealing and oxygen plasma could lead mass loss of polymeric materials, either one of the process can yield a narrowed patterns. However, the vacuum annealing process usually demands quite high temperatures (${\geq}300^{\circ}C$) and extended annealing time to get appreciable line-width reduction. Although the plasma treatment may be considered as an effective low temperature rapid process for the line-width reduction, it is also suffering for the lowered controllability on application to very fine patterns. We have found that the vacuum annealing temperature can be lowered by introducing the oxygen in the vacuum process and that the combination of oxygen plasma treatment with the vacuum annealing could yield the best result in the line-with reduction of the imprinted polymeric nanopatterns. Well-defined line width reduction by more than 50% was successfully demonstrated at relatively low temperatures. Furthermore, it was verified that this process was applicable to the nanopatterns of different shapes and materials.

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A Study on the Output Characteristic of Vacuum Booster (진공배력장치 출력특성에 대한 연구)

  • Lee, C.T.
    • Journal of Power System Engineering
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    • v.13 no.6
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    • pp.110-116
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    • 2009
  • In the present study, we proposed a simulation model of vacuum booster with AMESIM software to predict the output characteristic. And we performed the sensitivity analysis of output characteristic with main design parameters, such as diaphragm diameter. All of these parameters are main design parameters in the procedure of vacuum booster design. The simulation results of this paper offer qualitative information of vacuum booster output. Therefore, the simulation results of this paper will be used effectively for the design procedure of vacuum booster in the industrial field.

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Vacuum system for PAL-XFEL (4세대방사광가속기 진공시스템)

  • Na, Donghyun
    • Vacuum Magazine
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    • v.4 no.1
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    • pp.12-15
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    • 2017
  • The Pohang Accelerator Laboratory X-ray Free Electron Laser (PAL-XFEL) is a 0.1 nm hard X-ray FEL which aims at providing photon flux higher than $1{\times}10^{12}$ photons/pulse using a 10-GeV electron linac. The vacuum system of the machine consists of an injector section including an S-band photocathode RF gun, 10-GeV electron linac section based on S-band normal conducting accelerating structures and a 150-m long out-vacuum undulator system. We introduce the present status of PAL-XFEL vacuum systems.

Advances in Vacuum Microelectronics toward Vacuum Nanotechnology for FPDs

  • Nakamoto, Masayuki
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.299-302
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    • 2002
  • Vacuum microelectronics has been expected to provide a number of advanced devices such as flat panel displays, high-frequency devices etc., and rapidly showing tremendous and attractive aspects toward nanotechnology. Nowadays, nanomachining and nanomaterials are coming to new targets in the development for new generation devices. Transfer Mold technique has been developed for the vacuum nanotechnology. Carbon nanotubes (CNTs) are emerging as nanomaterials and expecting the new electron sources for FED. Recent progress of vacuum microelectronics toward vacuum nanotechnology in Japan are described.

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Leakage Analysis of Air Bearing for Vacuum Environment (진공환경용 공기베어링의 Leakage 해석)

  • 김경호;박천홍;이후상;김승우
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.912-915
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    • 2004
  • A vacuum environment is very important for NGL(Next Generation Lithography) apparatuses such as EUVL(Extreme Ultra Violet Lithography) or EPL(Electron Projection Lithography) and so on. The performance of these systems is dominated by vacuum level of processing and positioning accuracy of a stage. So, ultra-precision stage usable in a high vacuum level is needed for the improved performance of these devices. In contrast to atmospheric condition, a special attention must be paid to guide bearing, actuator and other elements. In this paper, air bearing is adopted because of its very high motional accuracy. So, air bearing is designed to be vacuum compatible using differential exhaust method, which prevents air from entering into vacuum chamber. For this, leakage analysis is performed theoretically and verified from experiment.

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A Study on the Rapid Cooling Vacuum System for the Storage and Transportation of the Cold Agriculture and Livestock Products (농축산물의 저장 및 유통을 위한 감압증발 급냉각 시스템에 관한 연구)

  • 김성규;김원녕;김경석;최순열;전현필
    • Journal of Advanced Marine Engineering and Technology
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    • v.21 no.1
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    • pp.26-36
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    • 1997
  • Recently, the new refrigerating system, using non - fluorinated hydrocarbon refrigerants has to be developed for the agricultural fields. One of that kinds of systems is the cooling system using the water vapor and vacuum, in which the water evaporate at the low temperature under vacuum and absorb the large amount of the latent heat. If vapor with large amount of latent heat is removed from the system, the system is cooled accordingly. The characteristics of cooling under the vacuum was observed and measured using experimental apparatus, which is consisted of vacuum chamber, the ejectors, the pumps and the measurement apparatus. As the results of experiments, we know that the evaporation in the vacuum occurs vigorously when the materials to be cooled has more amounts of heat before cooling, and by which effects the materials can be cooled. The cooling vacuum system is more efficient than other methods when the agricultural products is chilled or dried.

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