Magnetic-Levitation Substrate Rotation for Cleaning and Conveyance

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Solution Overview

Problem

Conventional substrate rotation devices lack efficient mechanisms for magnetically levitating and positioning inner cylinders during substrate cleaning and conveyance, leading to operational limitations and potential mechanical failures.

Innovation Solution

A substrate rotation device incorporating a radial motor and radial magnetic bearing system, where the inner cylinder is magnetically levitated using an attractive force between the magnetic bearing stator and rotor, allowing for up-down movement between cleaning and conveyance positions, and featuring a motor rotor length that accommodates both positions, facilitating efficient substrate handling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional substrate rotation device is used, then the device structure is simple, but the magnetic levitation and positioning of the inner cylinder is inefficient leading to operational limitations

Engineering Contradiction:

Improvemagnetic levitation stabilityVSAvoiddevice structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the motor and magnetic bearing functions into a unified structure where the motor stator and magnetic bearing stator are integrated on the outer cylinder, and the motor rotor and magnetic bearing rotor are integrated on the inner cylinder. This merging reduces the number of separate components while achieving both rotation and magnetic levitation functions simultaneously.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The outer cylinder and inner cylinder structure serves multiple functions: it acts as both the stator and rotor for the motor, and simultaneously as the stator and rotor for the magnetic bearing. This multi-functionality eliminates the need for separate magnetic levitation mechanisms while maintaining structural simplicity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If the inner cylinder is positioned for cleaning, then substrate cleaning is effective, but the device cannot simultaneously accommodate conveyance position requirements

Engineering Contradiction:

Improveposition accommodationVSAvoidoperational flexibility

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent employs dynamic positioning where the inner cylinder can be levitated to different heights along the axial direction. The magnetic bearing allows the inner cylinder to move between a lower cleaning position (where the substrate holder is near the outer cylinder opening) and an upper conveyance position, enabling flexible adaptation to different operational requirements.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent adds vertical movement capability along the axial direction to the traditional horizontal rotation system. By controlling the magnetic bearing to levitate the inner cylinder at different heights, the system gains an additional degree of freedom, allowing it to accommodate both cleaning and conveyance positions without compromising operational flexibility.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If mechanical contact is used for supporting the inner cylinder, then positioning is achievable, but mechanical stress and potential failures increase

Engineering Contradiction:

Improvemechanical failure resistanceVSAvoidmechanical stress

Core Design Contradiction:

ReliabilityVSStress or pressure

Solution Approach 1:

The patent replaces traditional mechanical contact bearings with a magnetic bearing system. The inner cylinder is levitated and supported by magnetic fields generated between the magnetic bearing stator (on the outer cylinder) and magnetic bearing rotor (on the inner cylinder), eliminating mechanical contact and associated wear, friction, and mechanical stress.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The magnetic bearing generates an upward magnetic force that counteracts the gravitational weight of the inner cylinder and substrate holder assembly. This magnetic lift force eliminates the need for mechanical support structures that would otherwise bear the mechanical load, reducing mechanical stress and potential failures.

Inventive Principle:

Principle #8Anti-weight (Counterweight)

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

Enables stable magnetic levitation and positioning of the inner cylinder, ensuring reliable substrate rotation and conveyance, while reducing mechanical stress and enhancing operational flexibility.

Implementation Method 1

a magnetic bearing that magnetically levitates the inner cylinder

Methodology Applied

Scientific EffectMagnetic levitation: Maglev

Implementation Method 2

The magnetic bearing is configured to magnetically levitate the inner cylinder with an attractive force between the magnetic bearing stator and the magnetic bearing rotor

Methodology Applied

Scientific EffectAttractive force between magnetic components: Magnetism

Implementation Method 3

a motor that rotates the inner cylinder... The motor is a radial motor including a motor stator mounted on the outer cylinder, and a motor rotor mounted on the inner cylinder

Methodology Applied

Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Data Source

PatentUS11731241B2Substrate rotation device, substrate cleaning device, substrate processing device, and control method for substrate rotation device

Publication Date: 2023.08.22 EBARA CORP

AI summary

An advanced substrate rotation device is provided. A substrate rotation device is disclosed. The substrate rotation device includes an outer cylinder, an inner cylinder positioned inside the outer cylinder, a motor for rotating the inner cylinder, a magnetic bearing for magnetically levitating the inner cylinder, and a substrate holder disposed on the inner cylinder. The motor is a radial motor including a motor stator mounted on the outer cylinder, and a motor rotor mounted on the inner cylinder. The magnetic bearing is a radial magnetic bearing including a magnetic bearing stator mounted on the outer cylinder, and a magnetic bearing rotor mounted on the inner cylinder. The magnetic bearing is configured to magnetically levitate the inner cylinder with an attractive force between the magnetic bearing stator and the magnetic bearing rotor.