• Journal of the Korean Vacuum Society
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• v.17 no.4
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• pp.292-301
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• 2008

As the industry requiring clean vacuum condition like semiconductor and display manufacturing expands, importance of dry vacuum pumps has been increased. Screw-type dry vacuum pump, occupying major share with multi-stage roots pump in dry-pump market, has big strength specially in harsh application area accompanying serious by-product accumulation. Recently, development in screw-type pump has been focused on improving energy efficiency. In this article, technology of screw-type dry vacuum pump is reviewed and the requirement for actual industrial application is considered. In addition, the expected evolution for screw-type dry pump in near future is also described.

• Journal of the Korean Vacuum Society
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• v.19 no.4
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• pp.265-274
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• 2010

The excellent performance and stability of dry-vacuum-pump is essential to create and maintain high quality vacuum condition in semiconductor and display process. The development of dry-vacuum-pump needs systematic consideration for target application as well as delicate mechanical issues. Here, we introduce a development procedures of dry-vacuum-pump for semiconductor-process-class.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.2
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• pp.67-74
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• 2015

In this study, analysis and experiments were carried out on temperature distributions and thermal deformations in a dry vacuum pump with vertical screws for safe operation. When a vacuum pump is working, it is necessary to get rid of the heat generated by the friction of bearings and the compression of air to prevent the vacuum pump from being damaged by interference between two screws and housing through thermal deformation. Additional cooling was proposed by using oil flow through the inner channel of the rotating axis for lower temperature control of the vacuum pump. Analysis and experimental results were compared in terms of temperature distribution and thermal deformation of the vacuum pump, and two sets of results matched reasonably well. These results for a dry vacuum pump with vertical screws can be used in similar model development and can minimize errors in design and manufacture by providing reasonably accurate prediction in advance.

• Vacuum Magazine
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• v.2 no.1
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• pp.31-34
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• 2015

This article introduces fundamentals of self-diagnosis and predictive (or preventive) maintenance technologies for dry vacuum pumps. The state variables of dry pumps are addressed, such as the pump and motor body temperatures, consumption currents of main and booster pumps, mechanical vibration, and exhaust pressure, etc. The adaptive parametric models of the state variables of the dry pump are exploited to provide dramatic reduction of data size and computation time for self-diagnosis. Two indicators, the Hotelling's $T^2$ and the sum of squares residuals (Q), are illustrated to be quite effective and successful in diagnosing dry pumps used in the semiconductor processes.

• Vacuum Magazine
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• v.2 no.4
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• pp.39-46
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• 2015

After stepping into a new field of vacuum 30 years ago, our company has grown up steadily as a specialized vacuum industry, and now we can provide vacuum devices covering most of the pressure range. We are planning to put out high level dry pump like a multistage Roots pump on the market in the near future. Procedures of technology development for designing, fabricating, and testing the multistage Roots pump of 600 L/min class will be briefly reported. Core items of the technical development on the multistage Roots pump are as follows; elaborated profile design of 3-lobe rotors using an involute curve, optimization of rotor dimensions, especially for clearances and rotor width, considering the pumping speed, compression ratio and heat load, and establishment of a standardized test system. At present, the multistage Roots pump is about to come into commercialization.

• Applied Science and Convergence Technology
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• v.24 no.1
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• pp.9-15
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• 2015

The practical pumping speed of a dry pump is considerably lower than the intrinsic speed because of back-streaming through finite gaps of the rotor assembly. The maximum compression ratio and the ultimate pressure of the pump are also directly influenced by the back-streaming rate. Therefore, information on the gap conductance, which determines the back-streaming characteristics of the rotor assembly, is the most important key for estimating the pumping performance of a dry pump. In this paper, the feasibility of calculating analytically the pumping performance of a multi-stage Roots pump, one of the most popular types of dry pumps, by quantifying the gap conductance in a rational way, is discussed.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.29-29
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• 2000

반도체 제조 공정을 비롯한 진공 산업에서는 진공 펌프에서 발생하는 backstream으로 인한 contamination이 주요 관심사가 되고 있다. 그러나 로타리 오일 펌프를 사용하는 경우에는 오일의 backstream으로 인한 contamination을 피할 수가 없어 현재는 오염 문제가 생산에 미치는 영향이 큰 반도체 공정에서는 건식 펌m을 적용/사용하고 있다. 본 발표서는 반도체는 제조 공정에 필수적으로 사용되고 있는 건식 펌프(dry pump)의 세계적 기술 동향을 살펴보고 건식펌프의 동작 원리 및 반도체 공정에서의 적용 사례등을 살펴보고자 한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.349-354
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• 2007

This paper considers acoustic analysis of silencer within a Dry vacuum pump. Main object is noise reduction of Dry Vacuum Pump using the silencer. First, we measured SPL and Intensity for noise source identification and then, designed for the silencer corresponding with noise character. 4-pole parameter are used for predicting transmission loss which is one of characteristics of silencer when we designed for silencer. Calculated Transmission Loss to change main effective factor and selected to optimal value using Design of Experiment. Finally, noise reduction is estimated to compare existing silencer with optimal silencer.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.10
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• pp.950-957
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• 2007

This paper considers acoustic characteristics of silencer within a dry vacuum pump. The main objective is to reduce noise in dry vacuum pump using the new designed silencer. First, SPL and sound intensity are measured for noise source identification and the new model silencer is designed corresponding to noise characteristics. 4-pole parameters are used to predict the transmission loss which is one of the interest characteristics of the new silencer. The calculated transmission loss is then used to change main effective factor and optimal value is selected by using design of experiment. By conducting an experiment, it is proved that the new designed silencer has reduced noise level by 6 dB(A) more than the original one.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.12
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• pp.1112-1119
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• 2011

The goal of this study is the stability evaluation of a vacuum pump through modal test and rotor dynamics. Roots type vacuum pump, which is a dry vacuum pump, is necessary for the manufacturing process of the semiconductor and the display. Eigenvalue was solved by the finite-element method(FEM) using 2D and 3D models, then the modal test result was compared with the FEM result. According to the comparison, the analysis result using the 2D was more accurate than the 3D model. Therefore, rotor dynamics was performed by the 2D model. Campbell diagram and root-locus maps, which were calculated by complex-eigenvalue analysis, were used to evaluate the stability of the rotors of the vacuum pump. And displacement solved by unbalance response analysis was compared with the minimum clearance between two rotors of the vacuum pump. Thus, the vacuum pump is assumed operated under steady state through the evaluation of the rotor dynamics.