Halbach Array Magnetic Suspension Damper for Photolithography
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Solution Overview
Problem
Current passive magnetic suspension vibration damping devices in photolithography apparatuses suffer from inefficient magnetic energy utilization and significant magnetic leakage, limiting their load-bearing capacity and precision.
Innovation Solution
A high-precision active magnetic suspension vibration damping apparatus utilizing a Halbach magnetic array with alternately arranged first and second magnetic units, each comprising 2x2 matrices of magnetically aligned bars, stacked to produce a magnetic force that enhances load-bearing capacity and optimizes magnetic energy utilization, while minimizing leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional N-S magnetic arrays are used for passive magnetic suspension vibration damping, then the device structure is simple, but the magnetic energy utilization is inefficient and magnetic leakage is significant
Solution Approach 1:
The patent applies the Halbach array configuration where permanent magnets are arranged with progressively rotated magnetization directions (0°, 90°, 180°, 270°) in a specific asymmetric pattern. This asymmetric arrangement creates a unidirectional magnetic field concentration effect that directs magnetic flux primarily in one direction while canceling leakage fields, thereby significantly improving magnetic energy utilization efficiency compared to traditional symmetric N-S arrays
Solution Approach 2:
The patent employs a multi-layer stacked structure where multiple Halbach array layers are arranged in sequence with alternating magnetization directions. Each layer is nested within the overall magnetic circuit structure, creating a composite magnetic field configuration that enhances load-bearing capacity while maintaining field concentration and reducing leakage through the nested arrangement
2Ease of manufacture
If traditional N-S magnetic arrays are used for passive magnetic suspension vibration damping, then the device structure is simple, but magnetic leakage is significant
Solution Approach 1:
The Halbach array's asymmetric magnetization pattern (0°, 90°, 180°, 270° progression) creates a self-shielding effect where the magnetic field is concentrated in the desired direction while the return path is configured to minimize leakage. This asymmetric design inherently reduces magnetic leakage without requiring additional shielding materials or complex structural modifications
Solution Approach 2:
The patent converts the potentially harmful magnetic leakage into a beneficial self-shielding effect by strategically arranging the magnetization directions of adjacent magnets in the Halbach pattern. The leakage fields from individual magnets are redirected to reinforce the main field or cancel each other out, transforming what would be wasted energy into a field-concentrating mechanism
3Device complexity
If passive magnetic suspension is used for vibration damping, then the device structure is simple, but the load-bearing capacity is limited
Solution Approach 1:
The patent achieves enhanced load-bearing capacity through a multi-layer stacked Halbach array structure where each layer contributes additively to the total magnetic force. The nested arrangement of multiple layers with alternating magnetization directions creates a cumulative effect that significantly increases the suspension force while maintaining the simplicity of the passive magnetic suspension principle
Solution Approach 2:
The patent combines multiple Halbach array layers into a unified magnetic suspension system where the individual magnetic fields of each layer merge to create a stronger overall field. This merging of multiple magnetic sources in a stacked configuration increases the load-bearing capacity while preserving the passive suspension approach
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
The apparatus achieves a higher load-bearing capacity with optimized magnetic energy utilization and reduced magnetic leakage, supporting precise vibration damping in photolithography systems by generating a magnetic field with twice the density of traditional N-S arrays, and maintaining low resonance frequencies.
Implementation Method 1
a Halbach magnetic array, including a plurality of first and second magnetic units alternately arranged and immediately adjacent to each other in a Y direction of the array
Implementation Method 2
each of the first magnetic columns is magnetized in a Z direction of the array, and each of the second magnetic columns is magnetized in a direction opposite to the Z direction of the array
Implementation Method 3
stacked together along a Z direction to produce a magnetic force in the Z direction
Implementation Method 4
high-precision active magnetic suspension vibration damping apparatus
Data Source
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AI summary
A Halbach magnetic array is disclosed, including a plurality of first and second magnetic units alternately arranged in a width direction, wherein: each first magnetic unit includes first magnetic groups and first magnetic columns alternately arranged in a length direction, each first magnetic group includes four first magnetic bars arranged in a 2*2 matrix; each second magnetic unit includes second magnetic groups and second magnetic columns alternately arranged in the length direction, each second magnetic group includes four second magnetic bars arranged in a 2*2 matrix; each first magnetic column is magnetized in a height direction, and each second magnetic column is magnetized in a direction opposite to the height direction. A magnetic suspension vibration damper is also disclosed which includes Halbach magnetic arrays as described above that are stacked together along a height direction to produce a magnetic force in the height direction and performs the vibration damping function by means of magnetic attractive forces or magnetic repulsive forces. As a Halbach array has a magnetic density on one side that is 2 times of a traditional N-S array, the damper can achieve a higher load-bearing capacity at the same magnetic energy product and produce a magnetic field on one side with characteristics allowing optimized utilization of magnetic energy product. In addition, the damper can also significantly alleviate the issue of magnetic leakage associated with the use of N-S arrays.