Coil current switching algorithm based on motion system of magnetic levitation planar motor of photo-etching machine

Abstract

The invention provides a coil current switching algorithm based on the motion system of the magnetic levitation planar motor of a photo-etching machine. Firstly, a coupling equation between the six-degrees-of-freedom force and the coil current of a planar motor mover is established. Secondly, mover coils are divided into a switching group and a non-switching group according to whether the mover coils will leave directly above a magnetic steel array during the motion of the planar motor mover, and the switching group is further divided into a sudden switching group and a gradient switching group according to the way the coils leave the magnetic steel array. An S function is used as a current switching weight function for the sudden switching group, and a cosine function is used as a currentswitching weight function for the gradient switching group. With the minimum 2-norm of all coil current vectors as the objective, the coupling equation of force and current is solved to obtain the current value of each coil. The heating loss of the coils of the planar motor can be reduced as much as possible, and smooth switching of the coil currents in the full motion range of the mover of a moving coil type magnetic levitation planar motor can be realized.

Description

technical field [0001] The invention relates to the technical field of semiconductor equipment, and more specifically, relates to a coil current switching algorithm based on a lithography machine magnetic levitation planar motor motion system. Background technique [0002] The planar motor directly uses electromagnetic energy to generate two-dimensional planar motion, which has the characteristics of high precision, high output density, and fast response, so it has important application prospects in the fields of semiconductors, liquid crystal screens and other two-dimensional processing. Compared with other planar motors, magnetic levitation planar motors are easier to control and have lower requirements for stator surface processing, so they are gradually attracting people's attention. [0003] In the double maglev worktable system of the lithography machine, in order to improve the yield of the chip, the chip manufacturing processes such as alignment measurement, leveling...

AI Technical Summary

Problems solved by technology

Considering the reduction of system energy loss and the improvement of system efficiency, the length of the magnetic steel array is limited, so that the sum of the lengths of the two magnetic levitation planar motors is greater than the length of the magnetic steel array, resulting in two magnetic levitation planar motors in the process of exchanging positions , some coils of the maglev planar motor mover will move out of the magnetic steel array, and the current of this part of the coil will suddenly become zero, resulting in a large terminal voltage at both ends of the coil, which will affect the control accuracy

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