OLED Adhesive Unit Additive Gradient for Moisture Delamination

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Solution Overview

Problem

Existing organic light-emitting display devices are vulnerable to moisture and oxygen infiltration, leading to defects such as dark spots and pixel shrinkage due to the expansion of additives in the dam member, which can cause cracks and delamination, reducing the device's reliability and lifespan.

Innovation Solution

The OLED display device incorporates an adhesive unit with a specific distribution of additives, where the highest concentration is at the center (moisture barrier region) and gradually decreases towards the edges, minimizing delamination and effectively protecting the organic light-emitting unit from lateral moisture and oxygen infiltration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additives are uniformly distributed in the adhesive unit, then moisture protection is provided, but volume expansion causes cracks and delamination

Engineering Contradiction:
Improvemoisture protectionVSAvoidstructural integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies local quality by creating three distinct regions with different additive concentrations: a first region with high concentration for moisture absorption, a second region with medium concentration for transition, and a third region with low concentration to prevent expansion damage. This gradient distribution allows the adhesive unit to provide effective moisture protection while maintaining structural integrity by strategically placing different material properties in different locations.

Inventive Principle:
Principle #3Local quality

2Reliability

If additives are positioned closer to the exterior, then moisture absorption is enhanced, but cracks and delamination increase

Engineering Contradiction:
Improvemoisture barrier effectivenessVSAvoidcracks and delamination
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by systematically varying the concentration parameter of additives across different regions. The first region near the exterior has the highest concentration for maximum moisture absorption, the second region has medium concentration for gradual transition, and the third region has the lowest concentration to minimize volume expansion effects. This parameter gradient resolves the contradiction between enhancing moisture absorption and preventing expansion-related damage.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If high concentration of additives is used, then moisture infiltration is suppressed, but volume expansion causes structural defects

Engineering Contradiction:
Improveprotection against moisture infiltrationVSAvoidstructural defects
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies segmentation by dividing the adhesive unit into three distinct regions based on additive concentration. This segmentation allows the high concentration needed for moisture protection to be localized in the first region, while the third region maintains low concentration to prevent expansion-related structural defects. The second region serves as a transition zone, creating a gradual gradient that resolves the contradiction between moisture suppression and structural integrity.

Inventive Principle:
Principle #1Segmentation

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 configuration enhances the protection of the organic light-emitting unit against moisture and oxygen, reduces delamination, and thereby improves the reliability and lifespan of the OLED display device by strategically distributing additives within the adhesive unit.

Implementation Method 1

as the additives contained in the dam member absorb infiltrating moisture from outside, the volume of the additives expands

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

An electron and a hole are respectively injected from the two electrodes into the organic light-emitting layer, and light is emitted by combining the injected electron and hole

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP2958159B1Organic light-emitting display device and method of manufacturing the same
Publication Date: 2020.03.11 LG DISPLAY CO LTD
  • EP2958159B1 patent drawingFigure 1
  • EP2958159B1 patent drawingFigure 2
  • EP2958159B1 patent drawingFigure 3A~3B

AI summary

Provided are an organic light-emitting display device and method of manufacturing the same. An organic light-emitting display device (100; 200) includes: an organic light-emitting unit (130; 230) between two substrates (110, 210; 210, 220), and an adhesive unit (150; 250) configured to fix the two substrates, the adhesive unit including: a plurality of additives (160; 260), and at least two regions (P1, P2, P3) configured to: suppress infiltration of external moisture into the organic light-emitting unit, and decrease separation of at least one of the two substrates from the adhesive unit caused by the external moisture, and wherein the at least two regions have respective concentrations of the plurality of additives different from each other.