Roll-to-Roll Plasma Cleaning with Roller Cooling for Flexible Substrates

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Solution Overview

Problem

Existing roll-to-roll plasma surface treatment devices face issues with overheating of transfer rollers, substrate quality deterioration due to temperature deviations, and the need for separate devices for different plasma surface treatment processes, especially in wet cleaning methods which are costly and inefficient.

Innovation Solution

A roll-to-roll plasma surface cleaning system using atmospheric pressure plasma generating devices with multiple plasma heads, incorporating a water cooling system to manage temperature and separate cleaning spaces for organic substances and oxide films, employing foaming gas and compressed air plasma beams for effective dry cleaning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wet cleaning is used to remove organic substances from substrate surface, then cleaning effectiveness is improved, but maintenance cost increases and cleaning time extends

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidcleaning time
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent replaces wet cleaning (mechanical/chemical system) with plasma cleaning (physical/chemical system). The plasma generating device creates reactive plasma species that chemically react with and remove organic substances from the substrate surface without requiring liquid cleaners, thereby eliminating maintenance costs and reducing cleaning time while maintaining effectiveness.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the cleaning method from liquid-based wet cleaning to gas-phase plasma cleaning. By altering the physical state and chemical properties of the cleaning medium (from liquid to plasma), the system achieves effective organic substance removal with reduced time and no maintenance requirements.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If plasma treatment is applied to flexible substrate, then organic substances are removed, but transfer roller overheats and substrate quality deteriorates

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidsubstrate damage from heat
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a cooling system as an intermediary between the plasma generating device and the transfer roller. The cooling medium absorbs excess heat from the plasma treatment process, preventing thermal damage to the flexible substrate while allowing the plasma cleaning to proceed effectively.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the harmful thermal energy generated during plasma treatment into a beneficial cooling effect. By strategically managing the heat through cooling systems, the previously harmful thermal radiation is transformed into controlled thermal management that protects the substrate while maintaining plasma cleaning effectiveness.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Device complexity

If single plasma generating device is used, then device complexity is reduced, but inability to perform multiple surface treatment processes simultaneously

Engineering Contradiction:
Improvenumber of plasma devicesVSAvoidsurface treatment process variety
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent designs a plasma generating device with multiple plasma heads that can perform different surface treatment processes simultaneously. Each plasma head is configured to deliver specific plasma parameters for different treatments (e.g., organic substance removal, oxide film removal, surface activation), allowing one device to replace multiple specialized devices while maintaining versatility.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent divides the plasma generating device into multiple independent plasma heads, each capable of performing specific surface treatment functions. This segmentation allows different plasma parameters and gas flows to be applied simultaneously to different areas of the substrate, enabling multiple treatment processes in a single device without excessive complexity.

Inventive Principle:
Principle #1Segmentation

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 system efficiently cleans large-scale flexible substrates with environmentally friendly dry methods, preventing substrate damage from plasma heating and allowing for multiple cleaning processes, while maintaining low maintenance costs and improving substrate quality.

Implementation Method 1

The plasma generating device generates plasma beams for cleaning the substrate surface

Methodology Applied
Scientific EffectPlasma: Plasma

Implementation Method 2

removing organic substances or oxide films attached to the surface of the material

Methodology Applied
Scientific EffectPlasma etching:

Implementation Method 3

a water cooling system to manage temperature

Methodology Applied
Scientific EffectConvection cooling: Convection

Implementation Method 4

heat of plasma radiated to the flexible substrate may be transferred to the drum through the flexible substrate

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3940744B1System and method for cleaning surface of substrate using roll-to-roll plasma generating device
Publication Date: 2023.12.20 LEE CHANG HOON
  • EP3940744B1 patent drawingFigure 1
  • EP3940744B1 patent drawingFigure 2
  • EP3940744B1 patent drawingFigure 3

AI summary

A roll-to-roll surface cleaning treatment system and method using a plasma generating device are provided, in which the system may includes an upper housing containing a first plasma generating device and a first transfer roller that faces a nozzle from which a plasma beam generated by the first plasma generating device is discharged and that winds and transfers a flexible substrate, the upper housing comprising a gas inlet, an entrance through which the flexible substrate is introduced, and an outlet through which the flexible substrate is discharged, and a lower housing connected to the entrance of the upper housing and containing a second plasma generating device and a second transfer roller that faces a nozzle from which a plasma beam generated by the second plasma generating device is discharged and that winds and transfers the flexible substrate, the lower housing comprising a gas outlet, and an inlet through which the flexible substrate is introduced, in which the upper housing is maintained at a low-temperature atmosphere by introducing a low-temperature refrigerant gas through the gas inlet.