Flexible OLED Encapsulation with Getter and Barrier Structure

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Solution Overview

Problem

Flexible substrates used in environmental sensitive elements, such as OLED devices, suffer from poor heat resistance, water, and oxygen resistance, leading to accelerated aging and reduced component lifetime, which does not meet commercial requirements.

Innovation Solution

A package and encapsulation method that includes a getter layer embedded within a package material on a flexible substrate, surrounded by a barrier structure, which is not located on predetermined fold lines, allowing the package to be folded for compactness while effectively resisting moisture and oxygen penetration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a getter structure is fabricated on the cover lid through adhesion, then moisture and oxygen resistance is improved, but the fabricated product loses flexibility

Engineering Contradiction:

Improvemoisture and oxygen resistanceVSAvoidflexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The device is divided into separate functional layers: the flexible substrate containing the OLED, and a separate cover lid with the getter structure. This segmentation allows the substrate to remain flexible while the cover lid provides protection, resolving the contradiction between flexibility and moisture/oxygen resistance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A sealing structure (including sealing adhesive and sealing ribs) acts as an intermediary between the flexible substrate and the cover lid. This intermediary creates a hermetic seal that maintains moisture and oxygen resistance while allowing the overall structure to maintain flexibility through the fold line.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If the OLED device uses a non-completely solid structure to be transparent, then transparency is improved, but the device becomes vulnerable to damage when bent

Engineering Contradiction:

ImprovetransparencyVSAvoidstructural integrity when bent

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The patent employs flexible thin film encapsulation layers (including the sealing adhesive layer and encapsulation adhesive layer) that provide both transparency and mechanical strength. These thin films maintain device integrity during bending while allowing light transmission, resolving the contradiction between transparency and structural integrity.

Inventive Principle:

Principle #30Flexible shells and thin films

3Adaptability or versatility

If flexible substrates are used for wide application and flexibility, then adaptability is improved, but heat resistance, water and oxygen resistance deteriorate

Engineering Contradiction:

Improveflexibility and wide applicationVSAvoidheat resistance, water and oxygen resistance

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent uses composite material structures combining the flexible substrate with protective layers including the cover lid, sealing adhesive, and encapsulation layers. This composite structure maintains the flexibility of the substrate while adding protective properties for heat, water, and oxygen resistance through the combined layers.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The protection against heat, water, and oxygen is achieved by adding protective layers in the vertical dimension rather than relying solely on the substrate properties. The multi-layer structure (substrate + sealing layers + cover lid) provides protection while maintaining the substrate's flexibility in the horizontal dimension.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 solution prolongs the lifetime of environmental sensitive elements by preventing moisture and oxygen ingress, enabling the package to be compactly folded and suitable for mass production.

Implementation Method 1

a second substrate is bonded to the first substrate by the filling layer

Methodology Applied

Scientific EffectAdhesion: Adhesive

Implementation Method 2

A getter layer is formed on the environmental sensitive element

Methodology Applied

Scientific EffectAdsorption: Adsorption

Data Source

PatentUS8624134B2Package of environmental sensitive element and encapsulation method of the same

Publication Date: 2014.01.07 HANNSTAR DISPLAY CORP

AI summary

An encapsulation method of an environmental sensitive element is provided. An environmental sensitive element and a first rib are formed on a first substrate. The first rib surrounds the environmentally sensitive element. A getter layer is formed on the environmental sensitive element. A first encapsulation layer is formed to encapsulate the getter layer and the first rib. The first barrier layer is formed to encapsulate the first encapsulation layer located on the first rib. The first rib, a portion of the first encapsulation layer located on the first rib and the first barrier layer form a barrier structure. A second substrate is provided on the first substrate and a filling layer is formed between the first substrate and the second substrate. The second substrate is bonded to the first substrate by the filling layer. The filling layer encapsulates the environmental sensitive element, the first encapsulation layer and the barrier structure.