Development of Planar Stage with Movable Magnet Array and Coil Switching Control

抄録

In recent years, as semiconductors have become finer and finer, their manufacturing equipment has been required to have nanometer-scale positioning. In such systems, the main sources of positioning error are friction, thermal deformation, and strain from the roller guides. Throughput is mainly limited by the heat generated by the motor coils and thermal deformation of the stage due to friction of the roller guides. Magnetic levitation (maglev) guides can prevent these two effects that limit positioning accuracy because they can provide non-contact support for the table. In particular, compared to a stacked maglev stage, a planar-type-maglev stage has a dramatically smaller moving mass, enabling high-speed movement with high positioning accuracy. From the viewpoint of reducing heat generation in the moving unit, it is desirable to install the magnet on the levitating side and the coil on the fixed side. However, a movable magnet type planar stage requires the use of a coil switching control system. In this study, a new magnetic levitation planar stage system with the movable magnet array and the coil switching control system was prototyped and evaluated. The basic characteristics of the prototype magnetic levitation stage were evaluated. As a result, stable levitation positioning by coil switching control was confirmed.