Vacuum Pump Flexible Cover Rotor Bolt Corrosion

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Solution Overview

Problem

Existing vacuum pumps used in semiconductor manufacturing face issues with corrosive process gases causing corrosion and rust on bolts, leading to foreign matter contamination and reduced processing quality due to dimensional errors allowing gas to flow back into the chamber.

Innovation Solution

A vacuum pump design featuring a flexible cover that elastically deforms to cover the recessed portion of the rotor, preventing exposure of bolts to process gases and using a reinforcing cover to support the flexible cover, reducing stress and enhancing durability, while also employing a rigidity lowering portion with punched holes for improved deformation and adhesion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a rigid cover is used to cover the recessed portion, then foreign matter prevention is improved, but stress concentration and durability are worsened

Engineering Contradiction:
Improveforeign matter preventionVSAvoidcover durability
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent employs a flexible cover made of elastic material that can deform to cover the recessed portion of the rotor. This flexible cover prevents foreign matter intrusion while accommodating dimensional variations and reducing stress concentration, thereby solving both the sealing and durability requirements simultaneously.

Inventive Principle:
Principle #30Flexible shells and thin films

2Stability of the object's composition

If the flexible cover is made more rigid to maintain shape, then coverage stability is improved, but stress resistance and durability are worsened

Engineering Contradiction:
Improvecover shape stabilityVSAvoidstress resistance
Core Design Contradiction:
Stability of the object's compositionVSStrength

Solution Approach 1:

The patent changes the material parameter of the cover from rigid to elastic/flexible material. This parameter change allows the cover to maintain its functional shape while being able to deform elastically under stress, thus achieving both shape stability and stress resistance through the material's elastic properties.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If dimensional errors in assembly are reduced, then sealing performance is improved, but manufacturing complexity and cost are worsened

Engineering Contradiction:
Improveassembly dimensional accuracyVSAvoidmanufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent transforms the static rigid cover into a dynamic flexible cover that can adapt its shape. This dynamic characteristic allows the cover to compensate for dimensional errors in assembly through elastic deformation, achieving good sealing performance without requiring high manufacturing precision, thus reducing manufacturing complexity.

Inventive Principle:
Principle #15Dynamics

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

Effectively prevents corrosion and rust of bolts, reduces foreign matter backflow into the chamber, and enhances the durability and longevity of the flexible cover, ensuring high-quality semiconductor processing by isolating the rotor from corrosive gases.

Implementation Method 1

a flexible cover having an outer peripheral portion supported on an end surface of the rotor that opposes the inlet port, and a central portion caved, namely, recessed into the recessed portion of the rotor, the flexible cover covering the recessed portion by elastically deforming into a convex shape toward the recessed portion

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3415766B1Vacuum pump with flexible cover and rotor
Publication Date: 2020.12.09 EDWARDS JAPAN
  • EP3415766B1 patent drawingFigure 1
  • EP3415766B1 patent drawingFigure 2(a)~2(b)
  • EP3415766B1 patent drawingFigure 3

AI summary

The present invention provides a vacuum pump that prevents invasion of foreign matter, such as rust and particles caused by a process gas, during the process of manufacturing a semiconductor wafer, and a flexible cover and a rotor that are used in the vacuum pump. A vacuum pump has a casing that has a gas inlet port and a gas outlet port, a rotor that has a recessed portion opened toward the gas inlet port and is fastened to a rotor shaft by a bolt disposed in the recessed portion. The recessed portion is provided with a flexible cover that has an outer peripheral portion supported on an end surface of the rotor that opposes the gas inlet port, and a central portion caved in the recessed portion of the rotor, the flexible cover covering the recessed portion by elastically deforming into a convex shape toward the recessed portion.