The design of a novel low-noise high-force linear motor for precision positioning applications, such as in semiconductor lithography, is presented in this paper. New magnetic designs achieve low noise and vibration by reducing high spatial-frequency magnetic field components, which cause harmonic vibrations of a moving stage. To reduce such force harmonic content, our new motor has fine teeth, narrow slots with high slot aspect ratio, five phases, and a moving skewed Halbach magnet array. As compared with a commercially available iron-core motor, in our new design, the acoustic noise level in Pascals is reduced by more than 90%, corresponding to a 20 dB reduction in sound pressure level, even with a nonskewed magnet array. Using a skewed magnet array, the cogging-driven and velocity-dependent noise is further reduced by 90% in Pascals. This new linear motor simultaneously is capable of very high shear force densities in order to support high-acceleration motions, and thus provides new options for high-performance and quiet linear motion devices.
Bibliographical noteFunding Information:
Manuscript received June 26, 2017; revised December 20, 2017, March 14, 2018, and April 4, 2018; accepted April 23, 2018. Date of publication May 10, 2018; date of current version July 30, 2018. This work was supported by ASML. (Corresponding author: Jun Young Yoon.) J. Y. Yoon and D. L. Trumper are with the Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 USA (e-mail: email@example.com; firstname.lastname@example.org).
All Science Journal Classification (ASJC) codes
- Control and Systems Engineering
- Electrical and Electronic Engineering