• Journal of the Korean Society of Safety
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• v.22 no.4
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• pp.32-36
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• 2007

When the vacuum system for the process of $SiH_{4}$ gas used in the semiconductor and FPD field is partially vented from vacuum to atmospheric state, a fire often occurs due to auto-ignition of $SiH_{4}$ gas. In order to prevent the fire, the concentration of $SiH_{4}$ should be kept under LFL. This means that the higher capacity pump is needed to meet the process conditions as well as the condition that the concentration of $SiH_{4}$ should be kept under LFL. In this article, we conducted the injection of the dilution gas at the manifold between booster pump and dry pump compared with the typical method that the dilution gas was injected into inlet port of booster pump using computer simulation. According to the result, we can flow further more purge gas for safety without any change of the condition in the process chamber, which means that the higher capacity pump is not required for safety in some cases.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.6
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• pp.675-684
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• 2000

A novel dry and wet deposition collector, which can overcome the several problems such as water evaporation cartridge cracks and high costs founded in the previous collector systems, has been constructed. ENVI-18 SPE adsorption cartridge has been used to measure atmospheric deposition of polycylic aromatic hydrocarbons (PAHs). A surrogate surface, consisted of water and methanol, was filled in the dry deposition funnel to simulate dry deposition onto water surface. A water supply system in order to compensat evaporation of the surrogate surface was used and it was consisted of a piston pump, a tubing pump, a overflow tube and a chamber system. A novel water vaporizing system to supply water onto the wet SPE cartridge system with a constant flow rate was developed. The novel water vaporizing system, consisted of a vacuum pump, a water supply reserviour and tube and a mini space heater, could prevent the PAHs adsorption cartridge cracks occurred in the previous collector and effectively adsorb PAHs. The novel dry and wet deposition collector showed a good adsorption, desorption, and recovery rates of PAHs. By reducing the number of pumps used and employing polypyopylene (PP) instead of teflon as a material of collection funnel, the total construction costs were much reduced as compared with the previous dry and wet deposition collectors.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.153-153
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• 2014

건식 진공펌프(dry vacuum pump)는 기계적 저진공펌프 중 펌프 내부의 기체 배기통로에 오일을 전혀 사용하지 않는 펌프의 통칭으로써, 대개 비접촉형으로 여러 형태의 회전자가 고속으로 회전하면서 흡기구로부터 들어온 기체를 압축해 배기를 한다. 비접촉형에는 루츠(roots)형, 클로(claw)형, 스크류(screw)형, 스크롤(scroll)형 등이 있다. 그 중 스크류형 펌프는 큰 배기속도를 갖는 펌프의 설계에 유리하고 높은 운용온도가 가능하여 다수공정에 쉽게 적용할 수 있는 장점이 있다. 그러나 1단 펌프 구성을 갖게 됨에 따라 루츠형 대비 높은 소비전력 특성을 보이는 약점을 가지고 있다. 본 논문에서는 건식 진공펌프 중의 하나인 스크류형 진공펌프에 대하여, 기본적인 1단 펌프 구성에 스크류 리드(lead)의 변화를 주어 기존의 똑같은 리드의 스크류 진공펌프에 대한 소비전력 및 배기구 온도 등 스크류 형상에 대한 성능평가 연구를 진행 하고자 한다.

• Applied Science and Convergence Technology
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• v.24 no.2
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• pp.27-32
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• 2015

We analyzed the destruction patterns of a turbo-molecular pump (TMP) resulting from its sudden exposure of a foreline to the atmospheric pressure due to a destruction of the foreline connecting clamp of an ICP dry etcher for 300 mm wafers during high-vacuum operation ($5{\times}10^{-6}$ Torr). Unlike in the case of view port's breakage, the TMP's rotor module was crashed inside the chamber. The primary damage resulted from the collision of the blades and stators, and the secondary damage resulted from the breaking of the rotor - driving shaft assembly. The fixing screws of the rotor and axial shaft were bent and broken when the TMP controller output the maximum current even after the crash event. Electrical power consumption analysis of the TMP power controller confirmed it. The stress distributions were analyzed by a finite element method using CFD-ACE+ multi physics software. Rotating inertia of each parts and kinetic energies were calculated as well. 68% of the rotational kinetic energy is deposited by the rotor - shaft module.

• Journal of the Korean Vacuum Society
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• v.18 no.6
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• pp.411-417
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• 2009

The constant volume flow meter system (the chamber volume in the 22 L class) was developed to estimate the pumping speed of the dry pump used for the industry of the next generation semiconductor and display. In order to insure the validity of the system, The base pressure and the leak rate in the enclosed system were checked, which were the $6{\times}10^{-8}\;mbar$ and $1.5{\times}10^{-6}\;mbar-L/s$, respectively. Furthermore, it is also confirmed that the value of throughput limit in this system was as much as 1 order of magnitude lower than that in a previously developed system in the 875 L class. By using this developed system, the pumping speed of the new small dry pump was measured. It is believed that the new developed system can be alternating the expensive constant pressure flow meter system in the range of $1{\times}10^{-2}\;mbar-L/s{\sim}1{\times}10^{-3}\;mbar-L/s$.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.17-17
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• 2010

This paper address technical issues in calibrating discharge coefficients of sonic nozzles used to measure the volume flow rate of low vacuum dry pumps. The first challenging issue comes from the technical limit that their calibration results available from the flow measurement standard laboratories do not fully cover the low vacuum measurement range although the use of sonic nozzles for precision measurement of gas flow has been well established in NMIs. The second is to make an ultra low flow sonic nozzlesufficient to measure the throughput range of 0.01 mbar-l/s. Those small-sized sonic nozzles do not only achieve the noble stability and repeatability of gas flow but also minimize effects of the fluctuation of down stream pressures for the measurement of the volume flow rate of vacuum pumps. These distinctive properties of sonic nozzles are exploited to measure the pumping speed of low vacuum dry pumps widely used in the vacuum-related academic and industrial sectors. Sonic nozzles have been standard devices for measurement of steady state gas flow, as recommended in ISO 9300. This paper introduces two small-sized sonic nozzles of diameter 0.03 mm and 0.2 mm precisely machined according to ISO 9300. The constant volume flow meter (CVFM) readily set up in the Vacuum center of KRISS was used to calibrate the discharge coefficients of the machined nozzles. The calibration results were shown to determine them within the 3% measurement uncertainty. Calibrated sonic nozzles were found to be applicable for precision measurement of steady state gas flow in the vacuum process. Both calibrated sonic nozzles are demonstrated to provide the precision measurement of the volume flow rate of the dry vacuum pump within one percent difference in reference to CVFM. Calibrated sonic nozzles are applied to a new 'in-situ and in-field' equipment designed to measure the volume flow rate of low vacuum dry pumps in the semiconductor and flat display processes.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.224-224
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• 2012

위성체가 작동하는 우주환경인 고진공상태에서는 위성체의 부품에서 발생 할 수 있는 outgassing으로 인해 위성체가 오염되어 위성체의 성능이 저하될 수 있으며, 특히 이차면경(second surface mirror) 및 광학렌즈 등을 오염시킴으로써 위성체 본연의 임무수행 실패라는 결과를 초래할 수도 있다. 따라서 지상에서 위성체의 부품에 대해 고온($85^{\circ}C$ 이상)과 고진공($5.0{\times}10-3Pa$ 이하)의 상태를 모사하여 오염물질을 제거함으로써 outgassing의 발생을 막고, 아울러 오염근원을 검출할 수 있는 vacuum bake-out 시험이 필수적이라 할 수 있다. 이를 위해서 한국항공우주연구원 위성시험동에는 전용 bake-out 챔버가 설치되어 있으며 저진공용 dry pump와 booster pump를 이용하여 5.0 Pa의 저진공을 형성하고, 2대의 cryopump를 이용하여 $5.0{\times}10-3Pa$ 이하의 고진공을 생성하게 되는데, Bake-out 챔버의 진공 배기시스템에 대하여 자세히 알아보고자 한다.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.02a
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• pp.27-27
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• 1998

진공기술의 응용과 진공환경의 이용은 더 이상 논하지 않더라도 산업 전반에 그 충요성이 점점 더 커가고 있다. 이러한 여건에도 불구하고 진공율 이용하는 system 개밟의 국산화는 수 입하는 system으$\mid$ 수에 비하여 절대적으로 부족하며, 또한 개발하는 system의 자동화는 거의 이 루어지지 않고 있으며, 자동화된 진공판련 system은 거의 대부분 수입에 의흔하고 있다. 실험 실 규모에서부터 System올 하나하나 개밭하고, 이톨 자동화하는 노력과 일이 진행됨다면 산업 응용에 있어서도 자연스럽게 자동화된 system으$\mid$ 개발이 이루어 질 것이다 .. system 자동화는 상 품수명의 단축과 이에 따른 다품종 소량을 요구하는 시장수요에 대응하고, 인력절감과 고풀짙 화로 생산성 향상의 요구에 대응하기 위하여 필요하다. 본 연 구에 서 는 e-beam evaporator로 evaporation하면 서 ion beam으로 assist하여 thin film율 제 작하는 IBAD vacuum system율 싫 계 및 제 작하고[1,2], PLC[3,떼톨 이 용하여 system 자동화톨 하였다 .. thin film 제작 process는 먼저 기본 진공상태로 만뚫고 난 뒤, e-beam evaporator로 e evaporation하면서 ion beam source로 assist하여 substrate 011 thin film율 제조한다 226;. thin film올 제 조하면서 thickness monitor로 sample의 thickness rate톨 control 하고, sample의 균얼성과 밀착 성을 고려하여 substrate톨 rotation 및 heating 할 수 있도록 싫계, 제작하였다. 양질의 박막올 제조하기 위해서 진공환경이 좋은 상태로 제공되어야 한다. 이톨 위하여 oil free operation 0 I 가 능한 dry pump와 turbo molecular pump로 고진공 배기 하였다. 진공도의 흑점은 thermal effect 툴 고려하여 cold cathode ion gauge률 사용하였고, intro chamber와 main chamber 사이에는 g gate valve톨 설치하여 벌도로 운용되도록 하였다. 이러한 process를 박막의 두께, 진공도, 시 간, 온도, 공정 동의 조건올 기훈으로 자동화한 것이다. 또한 정전과 단수에 대한 interlock 기능 도 고려하였다.하였다.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.581-590
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• 2008

A SWP method is a revolutionary dewatering method. The conventional dewatering method, deep-well method, had ever occurred a civil appeal caused by the well depletion in compliance with the reduction of the groundwater level over a wider area considerably by the deep-well pumping from homogeneous sand-layer ground for a dry-work, while pump groung excavation working in Sendai city, Japan 10 years ago. it'd developed with the problematic proposal to find the new method which can lower the groundwater level only within the sheet pile without any reduction of groundwater outside of the sheet pile and until currently steady improvement came. It's been confirmed with plenty of executional results that there was almost no decreasing of water-level from surroundings, over so many construction-sites including vertical shafts which completely does not enter into non-water permeable layer and pumping ground etc. The SWP method in this time has been introducing initially and carried into a the execution tentatively at a construction-site and made a various result get through the execution.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.221-224
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• 2004

드라이 펌프(Dry Pump)는 청결을 요구하는 반도체 생산 공정에 많이 사용하고 있다. 오늘날 반도체 수요의 증가와 함께 드라이 펌프의 수요도 늘어나고 있다. 그에 각 반도체 회사들은 진공 펌프의 선정이 매우 중요한 문제 중 하나로 대두대고 있다. 진공 펌프를 위한 종합 성능 평가 장치의 개발은 이들 회사에서 요구하는 펌프의 성능을 종합적으로 평가함으로써 펌프 선정의 중요한 근거 자료로 사용 할 수 있을 것이다. 본 연구에서 구축한 종합성능 평가 장치는 진공 펌프의 최대 도달 진공도(Ultimate Pressure), 배기속도(Pumping Speed), 전력 소비(Power Consumption), 진동(Vibration) 그리고 음향 파워(Sound Power)등과 같은 종합적인 성능을 한번에 평가 할 수 있다.