OLED Encapsulation Using Dual Barrier Layers and Adhesive Sealing

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Solution Overview

Problem

Optoelectronic devices like OLEDs face challenges with long-term stability due to environmental sensitivity to moisture and oxygen, which degrades device performance, and there is a need for improved encapsulation methods to address this issue.

Innovation Solution

The encapsulation method involves using a first and second barrier layer with an adhesive to seal an electroluminescence device, including conductive areas for electrical connection, and applying adhesives and protection layers to prevent moisture and oxygen ingress, with the option of lamination under controlled conditions to ensure effective sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the OLED device is left exposed to the environment, then the device structure remains simple and easy to manufacture, but the device performance degrades due to moisture and oxygen exposure

Engineering Contradiction:
Improvedevice stabilityVSAvoidencapsulation structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The encapsulation structure is divided into multiple functional layers: a first barrier layer (e.g., inorganic oxide layer) for primary protection against moisture and oxygen, and a second barrier layer (e.g., polymer layer) for additional protection and flexibility. This segmentation allows each layer to address specific protection requirements while maintaining overall device stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs composite encapsulation structures combining different material types - inorganic materials (such as aluminum oxide, silicon oxide) for the first barrier layer provide excellent barrier properties, while organic polymer materials for the second barrier layer provide flexibility and additional protection. This composite approach leverages the advantages of each material type to achieve superior overall protection.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If barrier layers and adhesives are added to protect the device, then environmental protection is improved, but the manufacturing process becomes more complex

Engineering Contradiction:
Improvemoisture and oxygen ingressVSAvoidencapsulation process complexity
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The encapsulation layers are applied in a predetermined sequence during the manufacturing process, with the first barrier layer formed first (e.g., through atomic layer deposition), followed by the second barrier layer. Adhesive layers are pre-applied to specific regions where electrical connections need to be maintained. This preliminary action approach ensures proper layer alignment and interface quality while streamlining the manufacturing process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Adhesive layers serve as intermediaries between the barrier layers and the OLED device structure, providing both mechanical bonding and electrical connectivity where needed. These intermediary layers facilitate the integration of multiple functional layers while maintaining device performance and simplifying the overall assembly process.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Illumination intensity

If transparent electrodes are used to allow light emission, then light transmission is improved, but electrical connection and sealing become more difficult

Engineering Contradiction:
Improvelight emissionVSAvoidelectrical connection and sealing
Core Design Contradiction:
Illumination intensityVSEase of operation

Solution Approach 1:

The encapsulation structure applies different properties to different regions: transparent barrier layers are used in areas requiring light transmission to maintain illumination intensity, while conductive adhesive regions are localized to specific contact areas where electrical connections are needed. This local differentiation allows the device to simultaneously achieve optimal light emission and electrical connectivity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The adhesive layers perform multiple functions: they provide mechanical bonding between layers, maintain hermetic sealing to prevent moisture and oxygen ingress, and enable electrical connections between transparent electrodes and external circuitry. This multi-functionality simplifies the overall device design by combining multiple requirements into single structural elements.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2460205B1Encapsulated optoelectronic device and method for making the same
Publication Date: 2018.09.26 BOE TECHNOLOGY GROUP CO LTD
  • EP2460205B1 patent drawingFigure 1~2
  • EP2460205B1 patent drawingFigure 3~4
  • EP2460205B1 patent drawingFigure 5~6

AI summary

An encapsulated optoelectronic device includes: a first banner layer; an electro!?minescence device configured to be coupled to the first barrier layer, and comprising a substrate and an electroluminescence element both defining a lateral side, and the electroluminescence element comprising a first electrode disposed on the substrate, a second electrode, and an optoelectronically active layer disposed between the first and second electrodes; a second barrier layer configured to be coupled to the electroluminescence device; and an adhesive configured to locate between and connect the first and second barrier layers, and at least to be coupled to the lateral side of the electroluminescence device to seal the electroluminescence device between the first and second barrier layers; a first conductive area disposed on the first harrier layer, located between the first and second barrier layers, and configured to be electrically coupled to the first electrode and electrically insulated from the second electrode and a second conductive area, the second conductive area disposed on the first barrier layer, located between the first and second barrier layers, and configured to be electrically coupled to the second electrode and electrically insulated from the first electrode and the first conductive area. A method for making the encapsulated optoelectronic device is also presented.