Graded-Composition Diffusion Barrier Coating for OLEDs

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Solution Overview

Problem

Conventional organic light-emitting diode (OLED) manufacturing processes face challenges with flexible substrates that are not impervious to oxygen and water vapor, leading to delamination issues and high manufacturing costs, and existing multilayer barrier structures suffer from poor adhesion and delamination during thermal cycles.

Innovation Solution

A selective deposition system that uses a deposition chamber with a web and shadow mask to apply a graded-composition diffusion-barrier coating selectively on substrates and electronic devices, ensuring protection from environmental reactive species while avoiding coating on sensitive areas like electric contacts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If flexible plastic substrates are used for OLED manufacturing, then mechanical flexibility and manufacturing cost are improved, but resistance to oxygen and water vapor permeation deteriorates

Engineering Contradiction:

Improvemanufacturing costVSAvoidresistance to oxygen and water vapor

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies composite materials by creating a multilayer barrier structure consisting of alternating polymeric and ceramic layers. The polymeric layer provides flexibility and masks defects in the ceramic layer, while the ceramic layer provides impermeability to oxygen and water vapor. This composite approach combines the advantages of both material types to achieve both flexibility and barrier protection.

Inventive Principle:

Principle #40Composite materials

2Reliability

If alternating layers of polymeric and ceramic materials are applied to improve substrate resistance, then resistance to oxygen and water vapor is improved, but adhesion between layers deteriorates due to material incompatibility

Engineering Contradiction:

Improveresistance to oxygen and water vaporVSAvoidadhesion between layers

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent employs parameter changes by implementing a graded-composition coating where the material composition transitions gradually from polymeric to ceramic phases. This gradual transition changes the physical and chemical parameters of the coating layers, reducing thermal stress and improving adhesion between incompatible materials while maintaining the barrier function.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If conventional batch-mode semiconductor fabrication processes are used for organic electronic devices, then manufacturing precision is maintained, but productivity and manufacturing cost deteriorate

Engineering Contradiction:

Improvefabrication precisionVSAvoidmanufacturing throughput

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent implements continuity of useful action by transitioning from batch-mode to continuous roll-to-roll fabrication processes. The substrate is continuously fed through the deposition chamber, allowing uninterrupted deposition of barrier coatings and fabrication of organic electronic devices, thereby significantly improving productivity while maintaining manufacturing precision through controlled deposition parameters.

Inventive Principle:

Principle #20Continuity of useful 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

The system provides a robust, mechanically stable, and environmentally resistant coating that decouples defects, preventing moisture and oxygen permeation, and maintains mechanical flexibility, thereby enhancing the durability and cost-effectiveness of OLEDs and other organic electronic devices.

Implementation Method 1

A selective deposition system that uses a deposition chamber with a web and shadow mask to apply a graded-composition diffusion-barrier coating selectively on substrates and electronic devices

Methodology Applied

Scientific EffectPhysical Vapour Deposition: Physical Vapour Deposition

Implementation Method 2

apply a graded-composition diffusion-barrier coating selectively on substrates and electronic devices, preventing moisture and oxygen permeation

Methodology Applied

Scientific EffectDiffusion Barrier: Diffusion Barrier

Data Source

PatentUS7976899B2Methods for selective deposition of graded materials on continuously fed objects

Publication Date: 2011.07.12 BOE TECHNOLOGY GROUP CO LTD

AI summary

Embodiments of the invention include a selective deposition method that allows for coating of selective portions of an object, such as an electronic device, and inhibits coating of other selective portions of the object, such as the electric contacts. The selective deposition method includes providing a web to transport the object through a deposition chamber. The web may include and reference mechanisms to register the object relative to the web. The method further includes providing deposition material and a shadow mask that has open spaces in it to inhibit coating selective portions of the object. The deposition material serves as the coating material.