Magnet-Stage Planar Motor with Halbach Array
Solution Overview
Problem
Existing displacement devices for electric planar motors in the semiconductor industry face challenges in achieving high accelerations and ease of handling, particularly due to complex configurations and interference from cables and hoses, which limit movement and accuracy.
Innovation Solution
A displacement device design where the magnet part, rather than the coil part, is movable, featuring a specific arrangement of magnets and coils with an interferometer system for precise positioning, allowing for quasi-unlimited range movement without cables, and utilizing Hall sensors and wireless communication for improved accuracy and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the coil part is made movable to achieve high accelerations, then productivity is improved, but device complexity increases due to cables and hoses attached to moving parts
Solution Approach 1:
Instead of making the coil part movable as in conventional designs, the patent inverts the approach by making the magnet part movable and the coil part stationary. This eliminates the need for cables and hoses to be attached to moving parts, thereby reducing device complexity while maintaining high acceleration capability through the strong magnetic field interaction.
2Ease of operation
If cables and hoses are attached to the moving part to supply power and cooling, then ease of operation is improved, but measurement precision deteriorates due to dynamic disturbances
Solution Approach 1:
The patent swaps the movable and stationary components so that the magnet part moves while the coil part remains stationary. This allows power and cooling supplies to be connected to the stationary coil part without creating dynamic disturbances, thereby maintaining high positioning accuracy while ensuring ease of operation for power and cooling delivery.
3Adaptability or versatility
If the range of movement is increased to allow greater flexibility, then adaptability is improved, but manufacturing precision deteriorates due to cumulative errors over long distances
Solution Approach 1:
The patent replaces mechanical positioning systems with an interferometer-based optical measurement system. This allows for precise position measurement over large ranges of movement (centimeters or more) without suffering from cumulative mechanical errors, thereby maintaining high manufacturing precision while achieving greater adaptability in terms of movement range.
4Manufacturing precision
If a dual-stage configuration is used to achieve long stroke and high precision, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent inverts the conventional approach by making the magnet part movable rather than the coil part. This single-stage configuration achieves both long stroke capability and high positioning precision through the strong magnetic field and interferometer measurement system, eliminating the need for complex dual-stage configurations while maintaining or improving manufacturing precision.
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 design enhances handling ease, reduces dynamic disturbances, and achieves high accuracy and flexibility in positioning, allowing for single-stage configurations and reduced thermal stress on wafers, while maintaining strong magnetic fields and efficient energy use.
Implementation Method 1
The magnets in each row and column are arranged according to a Halbach array, i.e. the magnetic orientation of successive magnets in each row and each column rotates 90° counter-clockwise. The second part comprises an electric coil system with two types of electric coils... The magnet configuration causes a very strong magnetic field.
Implementation Method 2
it further comprises an interferometer system for accurate positioning of the movable first part
Implementation Method 3
The magnets in each row and column are arranged according to a Halbach array, i.e. the magnetic orientation of successive magnets in each row and each column rotates 90° counter-clockwise. The magnet configuration causes a very strong magnetic field.
Data Source
AI summary
Especially for use in the semiconductor industry, a displacement device (701) is disclosed comprising a first part comprising a carrier (714) on which a system of magnets (710) is arranged according to a pattern of row and columns extending parallel to the X-direction and the Y-direction, respectively. The magnets in each row and column are arranged according to a Halbach array, i.e. the magnetic orientation of successive magnets in each row and each column rotates 90° counter-clockwise. The second part comprises an electric coil system (712) with two types of electric coils, one type having an angular offset of +45°, and the other type having an offset of −45° with respect to the X-direction. The first part (714, 710) is movable over a range of centimeters or more with respect to the stationary second part (712). For high precision positioning of the first part, an interferometer system (731, 730) is provided.