Airborne particle deposition in cleanrooms: Deposition mechanisms
نویسندگان
چکیده
This article discusses the mechanisms of particle deposition onto cleanroom surfaces. The main mechanism for particles above about 0.5μm is gravitational settling. Turbulent deposition and electrostatic attraction can also occur at all particle sizes, and for particles below 0.5μm Brownian diffusion is important. Measurements of particle deposition rates (PDRs) were made of particles 10μm on witness plates orientated in different directions and exposed in different ventilation conditions, and it was concluded that over 80% of particles were deposited by gravitational sedimentation, and probably more than half of the remainder by turbulent deposition.
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