• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.19 no.4
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• pp.225-232
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• 1990

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.8 no.1
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• pp.29-42
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• 1979

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.2
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• pp.202-210
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• 2015

Objectives: The purpose of this study was to examine clean room(C/R) structure, air conditioning and contamination control systems and to provide basic information for identifying a correlation between the semiconductor work environment and workers' disease. Methods: This study was conducted at 200 mm and 300 mm semiconductor wafer fabrication facilities. The C/R structure and air conditioning method were investigated using basic engineering data from documentation for C/R construction. Furthermore, contamination parameters such as airborne particles, temperature, humidity, acids, ammonia, organic compounds, and vibration in the C/R were based on the International Technology Roadmap for Semiconductors(ITRS). The properties of contamination control systems and the current status of monitoring of various contaminants in the C/R were investigated. Results: 200 mm and 300 mm wafer fabrication facilities were divided into fab(C/R) and sub fab(Plenum), and fab, clean sub fab and facility sub fab, respectively. Fresh air(FA) is supplied in the plenum or clean sub fab by the outdoor air handling unit system which purifies outdoor air. FA supply or contaminated indoor air ventilation rates in the 200 mm and 300 mm wafer fabrication facilities are approximately 10-25%. Furthermore, semiconductor clean rooms strictly controlled airborne particles(${\leq}1,000{\sharp}/ft^3$), temperature($23{\pm}0.5^{\circ}C$), humidity($45{\pm}5%$), air velocity(0.4 m/s), air change(60-80 cycles/hr), vibration(${\leq}1cm/s^2$), and differential pressure(atmospheric pressure$+1.0-2.5mmH_2O$) through air handling and contamination control systems. In addition, acids, alkali and ozone are managed at less than internal criteria by chemical filters. Conclusions: Semiconductor clean rooms can be a pleasant environment for workers as well as semiconductor devices. However, based on the precautionary principle, it may be necessary to continuously improve semiconductor processes and the work environment.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.6
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• pp.1178-1186
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• 2002

Clean stockers are being used by semiconductor and TFT-LCD manufacturers to store and buffer work in process. The only way to keep the stored product clean is to provide constant clean airflow the product and through stocker. Up to now, stockers typically have been configured to receive their laminar airflow from fan filter units that are located on the side of the stocker. This type of stocker may have such problems as complexity of structure, increment of temperature, mechanical vibration, initial investment and running cost. In this study, in order to solve the above mentioned problems, new air control system in stocker is proposed, which is to control open ratios of exits that are located on the side of the stocker without fan filter units. In this study, static pressure regain was used for the analysis of the open ratios of exits theoretically and experiment was also conducted using actual clean stocker for TFT-LCD manufacturers and CFDesign, was used for simulating airflow in stocker. As a result, open ratios of exits can be obtained by the analysis of static pressure regain and was verified by experiment and simulation results. Therefore, new air control system in stocker can be used by the semiconductor and TFT-LCD manufacturers.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.3
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• pp.547-554
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• 1992

Response characteristics and false counts of laser and white light optical particle counters (OPC) have been studied as a function of particle size using monodisperse polystylen laterx (PSL) particles. Theoretical light scattering calculations for He-Ne laser based counter have been compared with the experimental results and thus good agreements have been found. The light scattering intensity in monochromatic light shows an oscillatory character for the transparent and spherical particles of PSL due to Mie resonance. Because of this effect, the response of the LAS-X OPC showed almost same responses in the diameter ranges of 0.4mu.m to 0.6mu.m and 0.7mu.m to 1.0mu.m for PSL particles. A laser optical particle counter with high flow rate applied for clean room has been studied to identify the noise sources. Three different manufacturer's clean room optical particle counters alos have been tested to measure the background noise level.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.993-999
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• 2007

반도체나 TFT-LCD등을 생산하는 정밀산업 공장구조물에는 진동에 민감한 수많은 정밀장비(검사 및 생산용 장비)가 청정실(Clean Room)에 설치되어 운용된다. 정밀장비는 정상운용을 위하여 주변에 각종 유틸리티 설비가 설치된다. 이러한 수많은 유틸리티 설비들과 그 밖의 많은 장비들로 인하여 공장 내 청정실에는 각종 수 많은 소음/진동원들이 산재해 있다. 이러한 소음/진동원으로 인하여 청정실 내에는 소음/진동의 환경을 저하시킨다. 이에, 본 연구에서는 정밀장비 주변에 설치 된 유틸리티의 가동으로 인하여 발생하는 진동으로 인하여 간헐적으로 정밀장비에 영향을 미치는 과도진동의 현상을 확인하고, 과도진동 현상에 대하여 정밀장비에서 제시한 진동허용규제치와 비교/평가하고, 진동허용규제치의 유효성에 대하여 확인하였다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.1
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• pp.65-72
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• 2002

Generally, there are laser operating equipments( aligner, stepper) and electronic microscope( SEM, TEM) as a high precision manufacturing and inspection equipment in semiconductor production companies, precision examination and measuring laboratories. Mostly, these equipments are characterized by projection and target part. The relative displacements between projection and target part are dominant roles in vibrational problem in these precision equipments. These relative displacements are determined by the position of incoming vibration and the difference of vibration response in projection and target part. In this study, the allowable vibrational limits are suggested and the vibrational reduction plans are proposed by measurement and analysis of vibration phenomenon in the Clean Room in PDP(plasma display panel) production building. The vibration performance is evaluated by comparison relative displacements between projection and target part before/after the vibration isolation plan.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.4 no.2
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• pp.172-175
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• 2004

Generally, the yield rate of semiconductors is the major factor that affects directly the price of semiconductors. For a high yield rate of semiconductors, the air inside clean room is needed to be purified and high efficient filters are used for this. The filter are made of super-fine fiber and certain pinholes can be easily produced on the filter's surface by inadvertent manufacturing. As these pinholes are not easily detected with the bare sight, these pinholes exert a negative impact to filtration performance of the filter. In this research, not only the automatic test equipment for detecting pinholes is proposed, but also inverse modeling scheme based on artificial neural network is applied for tuning of its important parameters.

• Proceedings of the Safety Management and Science Conference
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• 2008.11a
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• pp.641-647
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• 2008

Since korea must get 5.2% reduction of green gas emission and insecurity of economic impact is on the increase due to unstable oil market, the demands of energy saving techniques are increasing. In this paper, we investigate necessity of development of enormous energy used cleanroom energy saving techniques furthermore we also investigate the adoption of dependability management system to develop the energy saving cleanroom development process.

• Journal of The Korea Institute of Healthcare Architecture
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• v.8 no.1
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• pp.7-12
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• 2002

The air ventilation system of operation rooms has been studied to prevent the cross infection during the operation. Operation rooms and air ventilation systems of three University hospitals were investigated. The distribution of microbe was measured by cultivating air samples in the operation room. A two-dimensional model for the cross-section of an operation room was developed for the CFD(Computational Fluid Dynamics) analysis. The characteristics of air flow in the empty operation room and in occupied operation room were calculated by using a CFD program. The current diffuser location of an old hospital did not deliver the clean air to the operation part efficiently. A new method to locate diffusers that improve air venting with little increase of the cost of equipment was suggested.