Multi-Layer Cathode Electrode Encapsulation for OLED Displays

Solution Overview

Problem

Electroluminescence displays face challenges in preventing moisture and gas penetration, which shortens the service life of organic light-emitting elements, requiring an additional encapsulation layer that increases manufacturing time and cost, and may have defective interface characteristics with the cathode electrode.

Innovation Solution

The cathode electrode is designed to function as both an encapsulation layer without a separate encapsulation layer, achieved by stacking multiple conductive layers such as a metal layer and a metal oxide layer, which simplifies the manufacturing process and enhances adhesion and protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separate encapsulation layer is applied to protect the organic light emitting element, then the encapsulation performance is improved, but the manufacturing time and cost increase

Engineering Contradiction:

Improveencapsulation performanceVSAvoidmanufacturing time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The cathode electrode is designed to serve dual functions: as the common electrode for electroluminescence and as the encapsulation layer for protecting the organic light emitting element. This merging of functions eliminates the need for a separate encapsulation layer, thereby reducing manufacturing time and process complexity while maintaining protection against moisture and gas penetration.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The cathode electrode structure is configured to perform multiple functions simultaneously. By incorporating an inorganic insulating layer within the cathode electrode stack, the structure provides both electrical functionality (as cathode) and protective functionality (as encapsulation layer), achieving multi-functionality that resolves the contradiction between protection and manufacturing efficiency.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a separate encapsulation layer is applied to protect the organic light emitting element, then the encapsulation performance is improved, but the manufacturing cost increases

Engineering Contradiction:

Improveencapsulation performanceVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The cathode electrode is designed to serve dual functions: as the common electrode for electroluminescence and as the encapsulation layer for protecting the organic light emitting element. This merging of functions eliminates the need for a separate encapsulation layer, thereby reducing manufacturing time and process complexity while maintaining protection against moisture and gas penetration.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The cathode electrode structure is configured to perform multiple functions simultaneously. By incorporating an inorganic insulating layer within the cathode electrode stack, the structure provides both electrical functionality (as cathode) and protective functionality (as encapsulation layer), achieving multi-functionality that resolves the contradiction between protection and manufacturing efficiency.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If an additional encapsulation layer is used, then the protection against moisture and gas is improved, but the interface characteristics with the cathode electrode may be defective

Engineering Contradiction:

Improveprotection against moisture and gasVSAvoidinterface characteristics

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The cathode electrode is designed to serve dual functions: as the common electrode for electroluminescence and as the encapsulation layer for protecting the organic light emitting element. This merging of functions eliminates the need for a separate encapsulation layer, thereby reducing manufacturing time and process complexity while maintaining protection against moisture and gas penetration.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

An inorganic insulating layer is introduced as an intermediary component within the cathode electrode structure. This layer serves as a mediator that provides both electrical insulation and protective encapsulation functions, ensuring good interface characteristics with the organic light emitting element while maintaining effective protection against moisture and gas penetration.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS20230209868A1Electroluminescence Display

Publication Date: 2023.06.29 LG DISPLAY CO LTD

AI summary

An electroluminescence display is disclosed. The electroluminescence display includes a cathode electrode having an encapsulation function. The electroluminescence display comprises: a substrate; an anode electrode on the substrate; an emission layer on the anode electrode; and a cathode electrode on the emission layer. The cathode electrode includes a plurality of conductive layers that are sequentially stacked.