Electroluminescence Display Sacrificial Layer Hydrogen Protection

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Solution Overview

Problem

Electroluminescence display apparatuses face issues with hydrogen and moisture exposure, leading to hot spots and degradation of the light emitting layer and thin film transistors, which affect image quality.

Innovation Solution

Incorporating a sacrificial layer with high reactivity to hydrogen and moisture in a dummy area, which absorbs and removes these substances, thereby protecting the active light emitting layer and thin film transistors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an encapsulation layer is provided to protect the light emitting layer and TFT from moisture, then reliability is improved, but hydrogen generated during encapsulation layer formation causes hot spots and degrades the light emitting layer

Engineering Contradiction:

Improveprotection from moistureVSAvoidhot spots from hydrogen

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The dummy emission area is segmented from the active emission area, allowing independent treatment of hydrogen protection. The sacrificial layer is specifically placed in the dummy area where hydrogen accumulates during encapsulation formation, protecting the light emitting layer without interfering with the encapsulation process

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A sacrificial layer is introduced as an intermediary substance between the hydrogen source (encapsulation layer formation process) and the light emitting layer. This sacrificial layer preferentially reacts with hydrogen, acting as a buffer that protects the light emitting layer from hydrogen-induced hot spots while allowing the encapsulation layer to be formed

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If the light emitting layer is made vulnerable to moisture for high performance, then image quality is improved, but degradation occurs when exposed to moisture and hydrogen

Engineering Contradiction:

Improveimage qualityVSAvoidresistance to degradation

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

Different regions of the display apparatus are given different protective qualities. The active emission area maintains high performance light emitting layer for image quality, while the dummy emission area contains a sacrificial layer providing enhanced protection against hydrogen and moisture. This local differentiation allows the light emitting layer to be highly sensitive to electrical signals for image quality while being protected in critical areas

Inventive Principle:

Principle #3Local quality

3Object-affected harmful factors

If a sacrificial layer with high reactivity to hydrogen is added in the dummy area, then protection from hydrogen is improved, but device complexity increases

Engineering Contradiction:

Improveprotection from hydrogenVSAvoidstructure complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The protection mechanism is added in a spatial dimension that does not interfere with the active display area. The sacrificial layer is placed in the dummy emission area, which is a separate region used for compensation and uniformity control. This dimensional separation allows the added protection mechanism to coexist with the simple active display structure

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The sacrificial layer is designed as a consumable protective element that is intentionally placed to be depleted or reacted during the encapsulation process. It serves its protective function against hydrogen and then can be removed or degraded, allowing a simple permanent structure to remain in the active area while providing temporary protection during manufacturing

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

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

Prevents hot spots and maintains image quality by effectively blocking and removing hydrogen and moisture from the light emitting layer and thin film transistors, ensuring the integrity of the display apparatus.

Implementation Method 1

a sacrificial layer which includes a material that is larger in reactivity with hydrogen or moisture than the dummy light emitting layer

Methodology Applied

Scientific EffectChemical reaction with hydrogen and moisture: Chemical Bonding

Data Source

PatentUS10388912B2Electroluminescence display apparatus

Publication Date: 2019.08.20 LG DISPLAY CO LTD

AI summary

Disclosed is an electroluminescence display apparatus for protecting a light emitting layer and a thin film transistor from hydrogen and moisture. The electroluminescence display apparatus includes a substrate including an active area displaying an image and a dummy area adjacent to the active area, a bank disposed on the substrate to form an emission area in the active area and form a dummy emission area in the dummy area, a light emitting layer and a dummy light emitting layer respectively disposed in the emission area and the dummy emission area, and a sacrificial layer disposed under the dummy light emitting layer in the dummy emission area. Since the sacrificial layer including a material which is large in reactivity with hydrogen and moisture is disposed in the dummy emission area, hydrogen and moisture may be blocked or removed so as not to affect the light emitting layer and a thin film transistor.