Stacked Linear Motor Assembly for Precise Air Gap Control
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Solution Overview
Problem
Current electromagnetic motors in lithographic apparatuses have a force density that is below expectations, limiting their ability to accurately position patterning devices and substrates during the manufacturing of integrated circuits, due to challenges in maintaining small gaps between magnet and coil assemblies in double-sided linear motors.
Innovation Solution
A motor assembly with a stacked arrangement of multiple magnet and coil assemblies, where each pair operates as a linear motor with independently controlled gaps, using flexible interfaces to maintain precise air gaps and enhance force density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a double-sided linear motor is used to increase force density, then the positioning capability is improved, but it becomes difficult to maintain small gaps between magnet and coil assemblies
Solution Approach 1:
The motor assembly is divided into multiple independent motor units, each comprising a magnet assembly and a coil assembly that can be independently positioned and gap-controlled. This segmentation allows each unit to maintain its gap independently, solving the problem of gap control in double-sided configurations.
Solution Approach 2:
The invention transitions from a planar double-sided motor configuration to a three-dimensional stacked arrangement where multiple motor units are arranged in layers. This dimensional change allows for better gap management and force integration while maintaining compact form factor.
2Measurement precision
If multiple magnet and coil assemblies are stacked to increase force density, then the positioning accuracy is improved, but the device complexity increases
Solution Approach 1:
Each motor unit is designed as a universal module that can be replicated and stacked. The magnet assemblies and coil assemblies use standardized interfaces and mounting mechanisms, reducing the complexity increment when scaling from single to multiple units.
Solution Approach 2:
Multiple magnet assemblies are combined on a single support structure, and multiple coil assemblies are integrated on a common frame. This merging approach consolidates control systems and structural elements, reducing overall complexity compared to fully distributed designs.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration allows for improved force density by maintaining small and accurately controlled gaps between magnet and coil assemblies, enhancing the positioning accuracy and throughput in lithographic apparatuses.
Implementation Method 1
a first electromagnetic assembly (1210) and a second electromagnetic assembly (1220), wherein the second electromagnetic assembly (1220) comprises a first electromagnetic sub-assembly (1222) configured to co-operate with the first electromagnetic assembly (1210) for generating a first driving force in the driving direction, and a second electromagnetic sub-assembly (1224) configured to co-operate with the first electromagnetic assembly (1210) for generating a second driving force in the driving direction
Data Source
Figure 1
Figure 2a~2b
Figure 3
AI summary
A motor assembly for driving an object in a driving direction is described, the motor assembly comprising: - a plurality of linear motors, each motor configured to generate a driving force in the driving direction, each of the linear motors comprising: - a first electromagnetic assembly and a second electromagnetic assembly, configured to co-operate with the first electromagnetic assembly, for generating the driving force; wherein the first electromagnetic assembly and the second magnetic assembly face each other and define a gap between each other in a direction perpendicular to the driving direction; - a first interface for connecting the first electromagnetic assemblies to a common member; - a second interface for connecting the second electromagnetic assemblies to the object to be driven; wherein the first electromagnetic assemblies and the second electromagnetic assemblies are stacked in the direction perpendicular to the driving direction, and wherein at least one of the first and second interfaces is configured to enable a relative displacement between the respective first electromagnetic assemblies and the second electromagnetic assemblies in the direction perpendicular to the driving direction.