마그네틱씰 개발 및 기밀 평가 시험

Magnetic seal uses a magnetic fluid to seal a gap between a rotating shaft and housing. It is distinguished from other kinds of seals from the fact that solid contact does not occur in the seal. This implies that it is free from solid rubbing thus dustless and provides a clean circumstance. That is the reason why the magnetic seal is used exclusively for most of vacuum chambers in semiconductor process where dustless clean circumstance is critical. A magnetic seal has been developed of which design parameters are determined based on published data, and an air pressure test has been done to examine its sealing capability. Effects of some design parameters have been studied through FEM analysis. The results show some notable aspects of design parameters and provide suggestions for developing the seals. Regarding the sealing capacity of the magnetic seal the factor to match the theoretical value with the actual one was found to be 0.4~0.7, which means still there is some discrepancy between theory and actual.