OLED Encapsulating Layer with Intermediate ALD Film

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Solution Overview

Problem

Organic light-emitting display apparatuses are prone to degradation due to external moisture and oxygen, requiring effective encapsulation to protect the OLED from environmental factors.

Innovation Solution

A thin film encapsulating layer is developed, comprising alternately laminated organic and inorganic layers, with specific thickness ranges and materials such as silicon oxide and aluminum oxide, including an intermediate layer formed by atomic layer deposition to enhance moisture-proofing and reduce layer stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single-layer inorganic encapsulating layer is used, then the manufacturing process is simple, but the moisture-proof performance is insufficient and delamination occurs

Engineering Contradiction:

Improvemoisture-proof performanceVSAvoidencapsulating layer structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies composite materials by creating a multi-layer encapsulating structure consisting of inorganic layers (silicon oxide, aluminum oxide) and organic layers (polyurea, polyacrylate) alternately laminated. This composite structure combines the barrier properties of inorganic materials with the flexibility and adhesion of organic materials, achieving superior moisture-proof performance while preventing delamination through material compatibility.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The encapsulating layer is segmented into multiple thin layers (50-500 Å each) rather than using a single thick layer. The structure includes alternating inorganic and organic layers, with the inorganic layers providing barrier function and organic layers providing flexibility and stress relief. This segmentation allows each layer to perform its specific function optimally while reducing overall delamination risk.

Inventive Principle:

Principle #1Segmentation

2Reliability

If the thickness of inorganic layers is increased to improve barrier performance, then moisture resistance improves, but layer stress increases and delamination risk increases

Engineering Contradiction:

Improvebarrier performanceVSAvoidlayer stress

Core Design Contradiction:

ReliabilityVSStress or pressure

Solution Approach 1:

The total barrier thickness is segmented into multiple thin inorganic layers (50-500 Å each) separated by organic layers. This segmentation maintains the barrier performance equivalent to thicker single layers while distributing and reducing mechanical stress across multiple interfaces, preventing delamination caused by stress concentration in thick single layers.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Organic layers act as intermediary layers between inorganic layers, providing stress relief and adhesion. These intermediary organic layers accommodate differential thermal expansion and mechanical stress between the rigid inorganic layers, preventing stress-induced delamination while maintaining the overall barrier integrity.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If multiple materials are used in the encapsulating layer, then moisture-proof performance improves, but manufacturing complexity increases

Engineering Contradiction:

Improvemoisture-proof performanceVSAvoidmanufacturing process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The manufacturing process is segmented into sequential deposition steps for different materials (silicon oxide, aluminum oxide, polyurea, polyacrylate) using established techniques like ALD and spin coating. Each material layer is deposited independently with controlled thickness, allowing precise control of barrier performance while using standardized manufacturing processes for each material type.

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

The encapsulating layer effectively protects the OLED from moisture and oxygen, reducing the risk of delamination and permeation, thereby increasing manufacturing yield and ensuring the longevity of the organic light-emitting display apparatus.

Implementation Method 1

the intermediate layer may include a first material and a second material and may be formed by atomic layer deposition

Methodology Applied

Scientific EffectAtomic layer deposition: Chemical Vapour Deposition

Implementation Method 2

performing plasma treatment on a surface of the first layer

Methodology Applied

Scientific EffectPlasma treatment: Plasma

Data Source

PatentUS9799849B2Organic light-emitting display apparatus and method of manufacturing the same

Publication Date: 2017.10.24 SAMSUNG DISPLAY CO LTD

AI summary

In an aspect, an organic light-emitting display apparatus and a method of manufacturing the same are provided. The organic light-emitting display apparatus may include a substrate; a display unit formed on the substrate; and a thin film encapsulating layer encapsulating the display unit. The thin film encapsulating layer may include a plurality of organic layers and inorganic layers that are laminated alternately. At least one of the plurality of the inorganic films may include a first layer formed of a first material, a second layer formed of a second material other than the first material, and an intermediate layer provided between the first and second layers.