Abstract
Air bearings have been widely used in ultra-precision positioning stages due to the property of nearly zero friction or wear. Small vibration of the bearing reduces the overall moving and positioning precision of the stage and hampers its applications in fabrication facilities requiring nanometer moving and positioning precision. In order to improve system precision, knowledge of the dynamic characteristics of air bearings is the first and crucial step. However, it is still a challenge to set up an accurate dynamic model for air bearings due to the system complexity. In this article, a novel method for the dynamic modeling of air bearing is proposed, which takes into account the dynamics in both the moving direction and the supporting direction. An ultra-precision positioning dual stage is investigated using the proposed dynamic modeling method. This stage has two sets of air bearings and can be used in integrated circuit fabrication equipments. Moreover, dynamic behaviors of the ultra-precision positioning dual stage are studied and compared with experimental results to validate the effectiveness and accuracy of the proposed method.
Highlights
The ultra-precision stage is a loading platform for precision positioning in multi-directions with high speed
With the advancement of technology, ultra-precision positioning stages are increasingly used in various industries, such as lithography, computerized numerical control (CNC) machine tools, micro or nano topography measurement, and so on, to achieve positioning motion with high speed and high precision.[1,2]
As the positioning stages on high precision are increasingly required, air bearings have been widely used in various ultra-precision positioning stages due to their merits of near zero friction or wear and less contamination.[3]
Summary
The ultra-precision stage is a loading platform for precision positioning in multi-directions with high speed. Two air bearing systems in the ultra-precision positioning dual-stage system are modeled as two sets of multiple distributed sliding springs, which represent as blue spring in this figure. In order to verify the proposed modeling method of air bearing, a dynamic model of the ultra-precision positioning dual stage is established, in which two air bearing systems are modeled using the method described in section ‘‘Dynamic modeling of the bearing system.’’ According to the proposed modeling method, an air bearing can be simplified as a sliding spring. In the ultra-precision positioning dual stage, the 12 air bearings of the air-foot can be simplified as 12 distributed sliding springs mentioned above, to ensure the fine stage floats on the granite base with no horizontal friction and high vertical stiffness.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
