Linear Motion System Carrier Train Formation
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Solution Overview
Problem
Current linear motion systems with linear synchronous motors lack the capability to efficiently control multiple carrier units as a single unit, which is essential for precise movement in applications like semiconductor substrate processing, where reducing the process chamber size and improving processing speed are critical.
Innovation Solution
The method involves forming a train of carrier units by arranging them such that the distance between identically poled magnets is an integer multiple of the magnetic pole-pitch, allowing them to be controlled as a single unit by applying current to the stator coil units, with sensors detecting the position of each unit for precise movement and commutation calculation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple carrier units are moved independently through the transport circuit, then each carrier can be processed separately with precise positioning, but the process chamber size and machine footprint increase
Solution Approach 1:
The patent merges multiple carrier units into a single train formation where carriers are positioned at integer multiples of the magnetic pole-pitch distance. This allows the linear synchronous motor to control the entire train as one unit, reducing the number of independent process chambers needed while maintaining precise positioning control through the magnetic field synchronization.
2Manufacturing precision
If carriers are processed one by one with stop-and-go movement, then precise positioning is achieved, but processing speed decreases
Solution Approach 1:
The patent enables continuous movement of carrier trains through the transport circuit without stop-and-go operations. By positioning carriers at integer multiples of the magnetic pole-pitch, the linear synchronous motor can maintain synchronized magnetic field propulsion throughout the entire train, allowing continuous processing at high speed while preserving positioning accuracy.
3Ease of operation
If buffers are used to manage carrier flow in the transport circuit, then carrier positioning flexibility is improved, but system complexity and space requirements increase
Solution Approach 1:
The patent eliminates the need for external buffers by enabling the linear synchronous motor to directly control the speed and positioning of entire carrier trains. The magnetic field synchronization allows the system to self-regulate carrier flow based on process requirements, reducing system complexity while maintaining operational flexibility.
4Ease of operation
If carrier units are arranged with non-integer multiples of magnetic pole-pitch, then individual carrier control is maintained, but train formation and space efficiency are lost
Solution Approach 1:
The patent changes the positioning parameter from arbitrary distances to specific integer multiples of the magnetic pole-pitch. This parameter change enables the magnetic field to synchronize across multiple carriers, forming efficient train formations that reduce machine footprint while still allowing individual carrier identification and control through the standardized spacing.
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 approach enables the formation of a single, continuous unit for processing, reducing the required space and enabling faster processing without buffers, while maintaining precise control and reducing chemical usage, particularly beneficial in CVD and sputtering processes.
Implementation Method 1
A magnetic travelling-field is generated for moving the translator(s). The stator includes separate coil units, each comprising at least one coil. Usually, the magnetic travelling-field is generated by applying a three-phase current to said coil units.
Implementation Method 2
The apparatus corresponding to the prior art comprises sensor devices, which are provided to detect the magnets of one product carrier and on the basis thereof to generate a position signal of the product carrier.
Data Source
AI summary
A method of controlling a linear motion system has a linear synchronous motor comprising a stator and at least two carrier units moveable in relation to the stator, the stator comprising a number of coil units, each of the at least two carrier units comprising a magnetic unit including an array of alternate-pole magnets having a regular magnet pole-pitch, wherein in order to form a train the at least two carrier units are arranged relative to each other so that the mutual distance between two identically poled magnets of two different magnetic units is an integer multiple of the magnet pole-pitch.