• 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.

• International journal of advanced smart convergence
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• 제10권1호
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• pp.159-165
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• 2021

Electronic devices used in the mobile environments fabricated under the plasma conditions in high vacuum system. Especially for the development of advanced electronic devices, high quality plasma as the process conditions are required. For this purpose, the variable conductance throttle valves for controllable plasma employed to the high vacuum system. In this study, we analyzed the effects of throttle valve applications on vacuum characteristics simulated to obtain the optimum design modelling for plasma conditions of high vacuum system. We used commercial simulator of vacuum system, VacSim(multi) on this study. Reliability of simulator verified by simulation of the commercially available models of high vacuum system. Simulated vacuum characteristics of the proposed modelling agreed with the observed experimental behaviour of real systems. Pressure limit valve and normally on-off control valve schematized as the modelling of throttle valve for the constant process-pressure of below 10-3 torr. Simulation results 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 in plasma process.

• International journal of advanced smart convergence
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• 제6권4호
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• pp.1-8
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• 2017

In this work, the effects of fairly influential factors on performance of vacuum system, such as constant pressure and outgassing effect were simulated to propose the optimum design factors. Outgassing effects of selected vacuum materials on the vacuum characteristics were simulated by the $VacSim^{Multi}$ simulation tool. This investigation examined the feasibility of reliably simulating the outgassing characteristics of common vacuum chamber materials (aluminum, copper, stainless steel, nickel plated steel, Viton A). The optimum design factors for vacuum systems were suggested based on the simulation results. And, the effects of throttle valve applications on vacuum characteristics were also simulated to obtain the optimum design model of variable conductance on 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. Simulation results were plotted as pump-down curve of chamber and variable conductance of throttle valve. Simulated behaviors showed the applications of throttle valve sustained the process-pressure constantly, stably, and reliably.

• 한국진공학회지
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• 제10권1호
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• pp.9-15
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• 2001

질량분석기가 장착된 초고진공챔버를 사용하여 미소체적을 갖는 평판표시소자용 패널내부에 존재하는 잔류가스의 전체압력과 분압을 성공적으로 측정하였다. 패널내부의 전체압력은 $10^{-6}$Torr범위로 측정되었으며, 전체압력의 증가에 크게 기여하는 가스분압은 아르곤, 메탄 및 헬륨 분압들이었다. 패널의 진공패키징을 위한 배기공정시 가열온도는 고진공패키징에 있어서 매우 중요하며, 가열배기 온도가 높을수록 전체압력과 메탄분압은 감소하였다.

• 한국철도학회논문집
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• 제13권5호
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• pp.516-520
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• 2010

튜브 구조물의 압력을 대기압 이하로 유지하는데에 사용될 진공 펌프의 용량을 설정하기 위한 파라메타 연구를 수행하였다. 최근 철도 기술 연구자들은 초고속 수송 시스템의 하나인 튜브 열차 시스템에 관심을 가지게 되었다. 초고속을 달성하기 위하여 튜브 내부를 저압으로 유지할 필요가 있는데, 저압에서는 공기 저항이 극단적으로 줄어들기 때문이다. 진공 펌프 시스템은 튜브 내부를 저압으로 만들고, 누설을 보충하는 역할을 한다. 일련의 연구결과, 다양한 파라메타에 대한 진공 펌프의 용량을 구하였다. 이 결과들은 공기 저항 저감 효과를 분석하는데에 적용될 것이다.

• International journal of advanced smart convergence
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• 제5권2호
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• pp.1-7
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• 2016

Recently, with the development of advanced thin film devices comes the need for constant high quality vacuum as the deposition pressure is more demanding. It is for this reason our research seeks to understand how the variable design factors are employed in such vacuum systems. In this study, the effects of design factor applications on the vacuum characteristics were simulated to obtain the optimum design modeling of variable models on an ultra high vacuum system. The commercial vacuum system simulator, $VacSim^{(multi)}$, was used in our investigation. The reliability of the employed simulator was verified by the simulation of the commercially available models of ultra high vacuum system. Simulated vacuum characteristics of the proposed modeling aligned with the observed experimental behavior of real systems. Simulated behaviors showed the optimum design models for the ideal conditions to achieve optimal pressure, pumping speed, and compression ratio in these systems.

• 한국정밀공학회지
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• 제26권8호
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• pp.112-118
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• 2009

A pressure rise is generated while air bearing stages are moving in high vacuum environment. This study analyzed this pressure rise phenomenon theoretically and verified it experimentally using two different kinds of stages - linear and rotary air bearing stages. Results indicate that the pressure rise was caused by additional leakage resulting from stage velocity, along with adsorption and outgassing of gas molecules from the guide rail surface. Though tilting of the stage due to acceleration and deceleration reached several micrometers, it had a negligible effect on pressure rise because the tilting time was very short. Therefore, a rotary air bearing stage showed much less pressure rise than a linear stage because the rotary stage theoretically has nothing to do with the above causes. Additional leakage caused by stage velocity was inevitable if the stage had movements, but pressure rise caused by adsorption and outgassing could be suppressed by improving the surface quality to reduce real surface area, and by coating the guide rail surface with titanium nitride (TiN) which has less adhesion probability of gas molecules. The results also indicate that the pressure rise increased when the air bearing stage operated under high vacuum conditions.

• 분석과학
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• 제17권5호
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• pp.375-380
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• 2004

고진공 및 고압장치를 이용하여 온도와 압력변화에 따른 친핵성치환반응을 속도론적으로 연구하여, 속도상수와 활성화파라미터 및 Hammett ${\rho}$값을 구하였다. ${\Delta}V^{\ddag}$, ${\Delta}{\beta}^{\ddag}$ 및 ${\Delta}S^{\ddag}$는 모두 음의 값을 나타내었으며, 모든 압력 조건에서 친핵체의 치환기효과 ${\rho}x$는 음의 값을 나타내었다. 압력이 증가함에 따라 반응속도는 증가하였으며, 진공상태에서의 반응속도는 다소 감소함을 알 수 있었으며, 반응은 $S_N2$ 반응메카니즘을 따름을 알 수 있었다.

• Journal of Korean Vacuum Science & Technology
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• 제6권3호
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• pp.109-115
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• 2002

This paper describes a CCM key comparison of low absolute-pressure standards at seven National Measurement Institutes that was carried out during the period March 1998 to September 1999 in order to determine their degrees of equivalence at pressures in the range 1 Pa to 1000 Pa. The Korea Research Institutes of Standards and Science(KRISS) participated from 10 Pa to 1000 Pa pressure range in 1999. The primary standards, which represent two principal measurement methods, included five liquid-column manometers and four static expansion systems. The transfer standard package consisted of four high-precision pressure transducers, two capacitance diaphragm gauges to provide high resolution at low pressures, and two resonant silicon gauges to provide the required calibration stability.

• 한국추진공학회지
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• 제26권1호
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• pp.98-106
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• 2022

고고도에서 작동하는 신뢰성 있는 이중펄스 추진기관을 개발하기 위해서는 안정적인 진공 점화 기술과 펄스분리장치(PSD, Pulse Separation Device) 설계기술이 요구된다. 본 연구에서는 이중펄스 추진기관 격막형 펄스분리장치(Membrane Type Pulse Separation Device)의 파열압력 분석기법을 개발하였다. 변형률-압력 관계를 이용하여 PSD 파열압력에 대한 관계식을 도출하였다. 고고도 진공환경을 모사할 수 있는 PSD 진공파열 시험장치와 PSD 1초급 진공점화 시험장치를 개발하였다. PSD 진공파열시험을 수행하여 파열압력을 분석하고 PSD 설계 값을 도출하였다. 최종적으로 PSD 1초급 진공점화 시험을 통해 이중펄스 추진기관의 PSD 설계 파열압력과 추진제 진공점화 성능을 확인하였다.