Particle and aerosol research (한국입자에어로졸학회지)

Korean Association for Particle and Aerosol Research (한국입자에어로졸학회)
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Numerical evaluation of risk rates for contamination sources in a minienvironment

클린룸 국소환경에서 오염원의 위험율에 대한 수치해석적 평가

  • Received : 2018.12.26
  • Accepted : 2018.12.28
  • Published : 2018.12.31
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Abstract

In this study, the risk rates of different contamination sources of the contaminant in a minienvironment were analyzed through Computational Fluid Dynamics (CFD) simulation. The airflow pattern characteristics can only predict the qualitative variation of contaminant concentration, but cannot evaluate the quantitative variations in the risk rate of sources. From the results, the ambient contamination sources mainly affect wafers in the Front Opening Unified Pod (FOUP), whereas the internal contamination sources mainly affect wafers laid on the robot arm in the minienvironment. And the purging plenum system is very useful in protecting the wafers in the FOUP from contaminants transferred from the Fan Filter Unit (FFU). However, this system is unable to protect the wafers on the robot arm from internal contaminants and the wafers in the FOUP from sources of the interface between the FOUP and the minienvironment.

Keywords

KKOSBF_2018_v14n4_181_f0001.png 이미지

Fig. 1. Description of critical zone and the linear summation of contaminants

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Fig. 2. Schematic design of the minienvironment system and positions of contamination source

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Fig. 3. Velocity vectors in the y-z plane of x = 0.5 m in the minienvironment system with FOUP for the simulated cases from 1 to 6

Table 1. Six different cases to evaluate the risk rate

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Table 2. The average concentrations of contaminant and the risk rates for external sources

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Table 3. The average concentrations of contaminant and the risk rates for internal sources

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