Anti-Reflective Coating on Plastic Substrates

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Solution Overview

Problem

Existing methods for producing anti-reflective coatings on plastic substrates are inefficient, particularly in batch mode systems, leading to reproducibility issues and limited throughput due to long process times, varying substrate material processing challenges, and fluctuating residual gas compositions.

Innovation Solution

A device with integrated process stations for sputtering, plasma etching, and protective layer application within a vacuum chamber, utilizing a plasma source with a curved magnetic field for efficient and controlled plasma treatment, enabling continuous substrate processing and automatic flow, with a conveyor system ensuring uniform layer deposition across substrates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If batch-operated systems are used for plasma treatment, then ventilation between process steps can be performed, but reproducibility deteriorates due to fluctuating residual gas composition and throughput is limited due to long charging and pumping times

Engineering Contradiction:
Improveventilation between process stepsVSAvoidreproducibility of surface treatment
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent combines multiple process stations (coating station, plasma treatment station, measurement station) into a single vacuum chamber, eliminating the need for ventilation between steps. This maintains constant residual gas composition throughout the process, ensuring reproducible surface treatment while enabling continuous processing without charging and pumping downtime.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements continuous processing by eliminating vacuum chamber ventilation between steps. The vacuum is maintained continuously throughout coating, plasma treatment, and measurement operations, allowing the useful action to proceed without interruption and preventing fluctuations in residual gas composition that would compromise reproducibility.

Inventive Principle:
Principle #20Continuity of useful action

2Ease of operation

If batch-operated systems are used for plasma treatment, then ventilation between process steps can be performed, but throughput deteriorates due to long charging and pumping times

Engineering Contradiction:
Improveventilation between process stepsVSAvoidthroughput of processing system
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent combines multiple process stations (coating station, plasma treatment station, measurement station) into a single vacuum chamber, eliminating the need for ventilation between steps. This maintains constant residual gas composition throughout the process, ensuring reproducible surface treatment while enabling continuous processing without charging and pumping downtime.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements continuous processing by eliminating vacuum chamber ventilation between steps. The vacuum is maintained continuously throughout coating, plasma treatment, and measurement operations, allowing the useful action to proceed without interruption and preventing fluctuations in residual gas composition that would compromise reproducibility.

Inventive Principle:
Principle #20Continuity of useful action

3Manufacturing precision

If conventional plasma etching is used on plastic substrates, then nanostructure can be formed, but processing time deteriorates becoming comparatively long

Engineering Contradiction:
Improvenanostructure formation on substrate surfaceVSAvoidprocessing time for etching process
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent applies a thin coating layer (such as oxide layer) to the plastic substrate before plasma treatment. This preliminary action modifies the substrate surface properties, enabling subsequent plasma etching to proceed much faster while still achieving the desired nanostructure formation, thus reducing overall processing time without sacrificing manufacturing precision.

Inventive Principle:
Principle #10Preliminary action

4Adaptability or versatility

If different substrate materials are processed, then various processing requirements must be met, but processing time deteriorates varying considerably for different materials

Engineering Contradiction:
Improveprocessing capability for different substrate materialsVSAvoidprocessing time variation across materials
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent applies a thin coating layer (such as oxide layer) to the plastic substrate before plasma treatment. This preliminary action modifies the substrate surface properties, enabling subsequent plasma etching to proceed much faster while still achieving the desired nanostructure formation, thus reducing overall processing time without sacrificing manufacturing precision.

Inventive Principle:
Principle #10Preliminary action

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 solution achieves high-quality, cost-effective, and reproducible anti-reflective coatings on plastic substrates with reduced process times and substrate temperatures, maintaining low residual gas levels and consistent composition, enhancing throughput and surface treatment efficiency.

Implementation Method 1

a base layer is applied to the substrate by means of a first sputtering unit

Methodology Applied
Scientific EffectSputtering: Sputtering

Implementation Method 2

a plasma source, which serves for plasma etching of the coated substrate surface

Methodology Applied
Scientific EffectPlasma etching: Plasma

Implementation Method 3

This nanostructure is produced by bombarding the substrate surface with high-energy ions generated by a plasma ion source

Methodology Applied
Scientific EffectIon bombardment: Ion Beam

Implementation Method 4

utilizing a plasma source with a curved magnetic field for efficient and controlled plasma treatment

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 5

a protective layer is applied to the processed substrate surface by means of a second sputtering unit

Methodology Applied
Scientific EffectSputtering: Sputtering

Data Source

PatentEP2761643B1Method and apparatus for producing a reflection reducing layer on a substrate
Publication Date: 2023.07.12 BUHLER ALZENAU GMBH
  • EP2761643B1 patent drawingFigure 1
  • EP2761643B1 patent drawingFigure 1a
  • EP2761643B1 patent drawingFigure 2~3

AI summary

The invention relates to an apparatus (1) for producing a reflection-reducing layer on a surface (21) of a plastics substrate (20). The apparatus comprises a first sputtering device (3) for applying a base layer (22) to the surface (21) of the plastics substrate (20), a plasma source (4) for plasma-etching the coated substrate surface (21), and a second sputtering device (5) for applying a protective layer (24) to the substrate surface (21). These processing devices (3, 4, 5) are arranged jointly in a vacuum chamber (2), which has inlets (8) for processing gases. In order to move the substrate (20) between the processing devices (3, 4, 5) in the interior of the vacuum chamber (2), a conveying apparatus (10) is provided which is preferably in the form of a rotary table (11). - Furthermore, the invention relates to a method for producing such a reflection-reducing layer on the surface (21) of the plastics substrate (20).