Contactless magnetically levitated silicon wafer transport system
ABSTRACT A new magnetically levitated wafer transport system is developed for the semiconductor fabrication process to get rid of the particle and oil contaminations that normally exist in conventional transport systems. The transport system consists of levitation, stabilization tracks, and a propelling system. Stabilities needed for levitation in the transport system are achieved by an antagonistic property produced in the tracks and using a simple feedback control. The continuous propelling force is obtained by sending specific current patterns to the propulsion coils. The dynamic model of the transport system is presented and analyzed.
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Conference Paper: Modular control system for a magnetic levitated stage[Show abstract] [Hide abstract]
ABSTRACT: We developed a magnetic levitated stage system, which allows precise positioning in six DoFs, with only one mover. It requires control of force in many points. Besides, the number of controlled points can vary with the travel range. For these reasons, a modular concept for the control and driving system is required. The paper presents the way in which the modularity is obtained in terms of control algorithm, embedded computing and driving.Automation, Quality and Testing, Robotics, 2008. AQTR 2008. IEEE International Conference on; 06/2008
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ABSTRACT: We investigate analytically and numerically trapping of submicron aerosol particles in a three-dimensional quadrupole acoustic chamber having hyperbolical configuration. The particle trajectories are described by the Langevin equation accounting for particle random Brownian motion. The particle trapping efficiency is investigated for a range of acoustic field parameters and particle properties. It is shown that submicron diffusive particles can be trapped in a small region near the chamber center. The effect of Brownian motion is to broaden the trapping region. The dimensions of the trapping region can be reduced by increasing the acoustic strength parameter.Particulate Science and Technology - PARTICULATE SCI TECHNOLOGY. 01/2011; 29(5):450-465.
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ABSTRACT: In this paper, a contactless linear slider for precision positioning able to operate in cryogenic environments is presented. The device, based on superconducting magnetic levitation, does not present contact between the slider (composed of a permanent magnet) and the guideline (made of high-temperature superconducting disks) of the mechanism, thereby avoiding any tribological problems. Moreover, the slider is self-stable and the superconductors provide inherent guidance to the permanent magnet in the sliding DoF due to the high translational symmetry of the magnetic field that leads to low power consumption. A sub-micrometre resolution and a symmetric stroke over ± 9 mm have been demonstrated at cryogenic temperatures. In addition, a set of design rules for this kind of mechanism has been proposed and experimentally validated. These rules demonstrate that the performance of the device can be tuned just by modifying some geometrical parameters of the mechanism. In this way, the sensitivity and stiffness, resolution, angular run outs and power consumption can be adjusted for different applications and requirements.Mechatronics 07/2013; · 1.30 Impact Factor