초순수 물(Ultra Pure Water)내 비휘발성 잔류 물질(Nonvolatile Residue, NVR)의 모니터링을 위한 NVR 측정시스템의 개발

The Development of Nonvolatile Residue (NVR) Particle Monitoring System in Ultra Pure Water

In this study, we developed nonvolatile residue (NVR) real-time monitoring system to measure the nonvolatile residue particle in ultra pure water (UPW). This device has a capability of measuring 4 different channels, i.e., 10 nm, 30 nm, 50 nm, and 100 nm. Until now, the light scattering method to detect RAE(residue after evaporation) was the only choice. However, this method can detect RAE larger than ca. 50 nm. In ultra pure water, RAE particles are usually very small and hard to detect with conventional laser scattering devices. To detect very small RAEs, a new system is developed and tested. The system consists of an atomizer that generates RAE particles and a four channel condensation particle counter (CPC). During the several months' operation in manufacturing line, the system was successfully tested and showed reliable results.