Oxynitride Encapsulation for OLED Moisture Protection

Solution Overview

Problem

Organic light emitting display devices are vulnerable to moisture and oxygen, leading to failures such as dark spots and pixel shrinkage, which existing encapsulation structures do not adequately address.

Innovation Solution

A multi-layer encapsulation structure using oxynitride and nitride materials, with varying ratios and compositions, is applied to seal the organic light emitting device, including a lower encapsulation layer with increasing oxynitride content closer to the organic layer, and an upper encapsulation layer to prevent moisture and oxygen ingress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a simple encapsulation structure is used, then the device complexity is reduced, but the protection against moisture and oxygen infiltration is insufficient

Engineering Contradiction:

Improveprotection against moisture and oxygenVSAvoidencapsulation structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The encapsulation structure is divided into multiple inorganic layers (first inorganic layer, second inorganic layer, third inorganic layer) with different material compositions. Each layer serves specific protective functions, creating a segmented barrier system that effectively blocks moisture and oxygen while maintaining manageable structural complexity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs composite material composition across different encapsulation layers, using nitride in the first layer, oxynitride in the second layer, and oxide in the third layer. This composite approach creates synergistic protection against moisture and oxygen infiltration, significantly improving reliability without excessive complexity

Inventive Principle:

Principle #40Composite materials

2Manufacturing precision

If the oxynitride content is uniformly distributed, then the manufacturing process is simplified, but the interface compatibility with organic layer is insufficient

Engineering Contradiction:

Improveinterface compatibilityVSAvoidgas pressure control

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The second inorganic layer features non-uniform oxynitride content distribution, with higher oxynitride concentration near the organic layer interface and lower concentration toward the third inorganic layer. This local quality variation optimizes interface compatibility and adhesion at critical regions without requiring complex overall manufacturing control

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements gradual changes in gas partial pressures (first gas, second gas, third gas) during deposition to achieve the desired non-uniform oxynitride content distribution. By controlling parameter transitions rather than maintaining fixed values, the method achieves precise compositional gradients while keeping the manufacturing process manageable

Inventive Principle:

Principle #35Parameter changes

3Illumination intensity

If a single inorganic layer is used, then the device complexity is reduced, but the light emission quality is insufficient

Engineering Contradiction:

Improvelight emission qualityVSAvoidnumber of inorganic layers

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The encapsulation structure is divided into multiple inorganic layers (first inorganic layer, second inorganic layer, third inorganic layer) with different material compositions. Each layer serves specific protective functions, creating a segmented barrier system that effectively blocks moisture and oxygen while maintaining manageable structural complexity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs composite material composition across different encapsulation layers, using nitride in the first layer, oxynitride in the second layer, and oxide in the third layer. This composite approach creates synergistic protection against moisture and oxygen infiltration, significantly improving reliability without excessive complexity

Inventive Principle:

Principle #40Composite materials

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 encapsulation structure effectively enhances the durability and light-emitting efficiency of the organic light emitting display device by preventing damage from external moisture and oxygen, thereby improving display quality and extending the device's lifespan.

Implementation Method 1

a lower encapsulation layer, which is provided on the organic light emitting device and includes oxynitride and nitride

Methodology Applied

Scientific EffectBarrier property:

Implementation Method 2

depositing an inorganic material to form a lower encapsulation layer on the organic light emitting device

Methodology Applied

Scientific EffectPhysical vapor deposition: Physical Vapour Deposition

Data Source

PatentUS10658616B2Display device and method of fabricating the same

Publication Date: 2020.05.19 SAMSUNG DISPLAY CO LTD

AI summary

A display device may include an organic light emitting device and an encapsulation member provided on the organic light emitting device to seal the organic light emitting device. The encapsulation member may include a lower encapsulation layer, which is provided on the organic light emitting device and includes oxynitride and nitride, an organic layer provided on the lower encapsulation layer, and an upper encapsulation layer provided on the organic layer. A content of oxynitride in the lower encapsulation layer may increase with decreasing distance from the organic layer.