에어 스테이지의 동적 특성에 미치는 가속도 및 감속도의 영향

• Published in: Tribology and Lubricants Vol. 36; no. 1; pp. 39 - 46
• Main Authors: 박상준(Sang Joon Park), 이재혁(Jae Hyeok Lee), 박상신(Sang-Shin Park), 김규하(Gyu Ha Kim)
• Format: Journal Article
• Language: Korean
• Published: 한국트라이볼로지학회 2020
• Subjects: 기계공학; deceleration; acceleration; air bearing stage; dynamic analysis; COMSOL
• ISSN: 2713-8011; 2713-802X
• DOI: 10.9725/kts.2020.36.1.39

Air stages are usually applied to precision engineering in sectors such as the semiconductor industry owing to their excellent performance and extremely low friction. Since the productivity of a semiconductor depends on the acceleration and deceleration performance of the air stage, many attempts have been made to improve the speed of the stage. Even during sudden start or stop sequences, the stage should maintain an air film to avoid direct contact between pad and the rail. The purpose of this study is to quantitatively predict the dynamic behavior of the air stage when acceleration and deceleration occur. The air stage is composed of two parts; the stage and the guide-way. The stage transports objects to the guideway, which is supported by an externally pressurized gas bearing. In this study, we use COMSOL Multiphysics to calculate the pressure of the air film between the stage and the guide-way and solve the two-degree-of-freedom equations of motion of the stage. Based on the specified velocity conditions such as the acceleration time and the maximum velocity of stage, we calculate the eccentricity and tilting angle of the stage. The result shows that the stiffness and damping of the gas bearing have non-linear characteristics. Hence, we should consider the operating conditions in the design process of an air stage system because the dynamic behavior of the stage becomes unstable depending on the maximum velocity and the acceleration time.