Compliant OLED Encapsulation Layer for Moisture and Flex Protection

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Solution Overview

Problem

OLED displays are sensitive to moisture and require precise humidity control, and as they grow in size, the encapsulation container can cause mechanical damage to electrodes or lead to shorting due to flexing of the substrate.

Innovation Solution

An OLED display design featuring a substrate with spaced-apart electrodes and organic layers, a desiccant material over at least one electrode, a compliant protection layer with a Young's Modulus less than 4 GPa, and an encapsulation container fixed over the compliant layer to prevent mechanical damage and maintain moisture protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a rigid encapsulation container is used to protect the OLED, then moisture protection is improved, but mechanical damage risk increases due to substrate flexing

Engineering Contradiction:

Improvemoisture protectionVSAvoidmechanical damage risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces rigid encapsulation containers with a flexible thin film encapsulation layer having a Young's Modulus of less than 4 GPa. This flexible layer can accommodate substrate flexing without transmitting damaging mechanical forces to the OLED electrodes, while still providing effective moisture protection through its barrier properties.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The patent changes the mechanical parameter (Young's Modulus) of the encapsulation layer from rigid values to flexible values (less than 4 GPa). This parameter change allows the encapsulation layer to deform with substrate flexing, preventing mechanical damage while maintaining moisture protection functionality.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If desiccant material is placed inside the encapsulation container, then moisture protection is improved, but mechanical damage risk increases due to contact with OLED electrodes

Engineering Contradiction:

Improvemoisture protectionVSAvoidelectrode contact damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a flexible intermediary layer between the desiccant material and the OLED electrodes. This intermediate layer physically separates the desiccant from direct contact with the electrodes, preventing mechanical damage and shorting, while still allowing the desiccant to perform its moisture absorption function through the flexible layer.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the substrate is made flexible to accommodate large OLED sizes, then device adaptability is improved, but mechanical stability worsens

Engineering Contradiction:

Improveflexibility for large sizeVSAvoidmechanical stability

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent employs a flexible thin film encapsulation layer that can deform with substrate flexing, maintaining mechanical stability and protecting the OLED structure during substrate deformation. This flexible layer accommodates substrate flexibility for large OLED sizes while preventing structural damage.

Inventive Principle:

Principle #30Flexible shells and thin films

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 design enables flexible encapsulation, reducing the risk of mechanical damage and shorting while maintaining electrical and moisture protection, allowing for low-cost, thin OLED displays.

Implementation Method 1

a compliant protection layer having a Young's Modulus

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

first desiccant material disposed over at least a portion of one of the electrodes

Methodology Applied

Scientific EffectAdsorption: Adsorption

Data Source

PatentUS8022624B2Moisture protection for OLED display

Publication Date: 2011.09.20 GLOBAL OLED TECHNOLOGY LLC

AI summary

An OLED display, comprising: a substrate; an OLED having two spaced-apart electrodes and organic layers disposed therebetween and the OLED being disposed over the substrate; first desiccant material disposed over at least a portion of one of the electrodes; a compliant protection layer having a Young's Modulus <4 GPa disposed over at least a portion of the first desiccant material; and an encapsulation container fixed to the substrate and disposed over the compliant protection layer.