Optimum design of voice coil motor using for nano-stage in lithographic equipment

An optimized structure of a voice coil motor with a lower force ripple was presented. Through improving the part of the magnet or the back iron of a voice coil motor's structure, its internal vertical peak flux density was reduced greatly. In this way, the motor's peak force was also reduced with force ripple. Different optimization results were compared and analyzed, and an electromagnetic simulation was carried out to verify the theoretical analysis. Finally, the advantages of the optimization scheme were given as a conclusion.