OLED Encapsulation Layer Alignment for Moisture Barrier

Solution Overview

Problem

Existing organic light-emitting display panel manufacturing techniques face challenges in achieving full-screen displays due to issues with moisture and oxygen infiltration, which affect the service life and functionality of the light-emitting device layer, particularly at the borders of the second electrode and encapsulation layers.

Innovation Solution

The solution involves a flexible substrate with a display region, an aperture region, and a non-display region, where a thin film transistor layer and a light-emitting device layer are formed, and an encapsulation layer comprising a first inorganic and a first organic layer are aligned with the borders of the second electrode, and an inorganic layer covers these borders to prevent moisture and oxygen ingress, enhancing the encapsulation effect and service life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the aperture region is enlarged to achieve full-screen display, then the display area is increased, but moisture and oxygen infiltration at the borders of the second electrode and encapsulation layers worsens, reducing service life

Engineering Contradiction:

Improvedisplay areaVSAvoidservice life

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The encapsulation layer is divided into multiple layers: a first inorganic encapsulation layer, a first organic encapsulation layer, and a second inorganic encapsulation layer. This segmented multi-layer structure provides better moisture and oxygen barrier properties compared to a single encapsulation layer, thereby improving reliability while maintaining the enlarged display area.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The encapsulation structure combines different materials (inorganic and organic layers) to create a composite encapsulation system. The inorganic layers provide excellent barrier properties against moisture and oxygen, while the organic layer provides flexibility and stress relief, together enhancing the service life of the light-emitting device layer in the full-screen display configuration.

Inventive Principle:

Principle #40Composite materials

2Area of stationary object

If the aperture region is enlarged to achieve full-screen display, then the display area is increased, but the risk of moisture and oxygen infiltration at borders increases

Engineering Contradiction:

Improvedisplay areaVSAvoidmoisture and oxygen infiltration

Core Design Contradiction:

Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The encapsulation layer is divided into multiple layers: a first inorganic encapsulation layer, a first organic encapsulation layer, and a second inorganic encapsulation layer. This segmented multi-layer structure provides better moisture and oxygen barrier properties compared to a single encapsulation layer, thereby improving reliability while maintaining the enlarged display area.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The encapsulation structure combines different materials (inorganic and organic layers) to create a composite encapsulation system. The inorganic layers provide excellent barrier properties against moisture and oxygen, while the organic layer provides flexibility and stress relief, together enhancing the service life of the light-emitting device layer in the full-screen display configuration.

Inventive Principle:

Principle #40Composite materials

3Ease of manufacture

If conventional encapsulation structure is used, then manufacturing is simpler, but moisture and oxygen blockage effectiveness is insufficient

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidmoisture and oxygen infiltration

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The encapsulation layer is divided into multiple layers: a first inorganic encapsulation layer, a first organic encapsulation layer, and a second inorganic encapsulation layer. This segmented multi-layer structure provides better moisture and oxygen barrier properties compared to a single encapsulation layer, thereby improving reliability while maintaining the enlarged display area.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The encapsulation structure combines different materials (inorganic and organic layers) to create a composite encapsulation system. The inorganic layers provide excellent barrier properties against moisture and oxygen, while the organic layer provides flexibility and stress relief, together enhancing the service life of the light-emitting device layer in the full-screen display configuration.

Inventive Principle:

Principle #40Composite materials

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 significantly improves the service life of the light-emitting device layer by effectively blocking moisture and oxygen, thereby enhancing the reliability and performance of the organic light-emitting display panel.

Implementation Method 1

an inorganic layer, and the inorganic layer covers the borders of the second electrode and the first inorganic encapsulation layer in the first non-display region

Methodology Applied

Scientific EffectPhysical barrier (encapsulation): Physical Containment

Implementation Method 2

manufacturing a light-emitting device layer on the thin film transistor layer, and manufacturing the light-emitting device layer comprises sequentially manufacturing a first electrode, a light-emitting layer, and a second electrode on a side of the thin film transistor layer facing away from the flexible substrate by evaporation

Methodology Applied

Scientific EffectEvaporation: Evaporation

Implementation Method 3

a dry-etching step so that borders of the first inorganic encapsulation layer and the second electrode in the first non-display region are aligned

Methodology Applied

Scientific EffectDry etching: Plasma

Data Source

PatentUS10224508B2Organic light-emitting display panel, method for manufacturing organic light-emitting display panel and organic light-emitting display device

Publication Date: 2019.03.05 SHANGHAI TIANMA MICRO ELECTRONICS CO LTD

AI summary

An organic light-emitting display panel, a method for manufacturing the same and an organic light-emitting display device are provided. The organic light-emitting display panel includes a flexible substrate comprising a display region, an aperture region surrounded by the display region, and a first non-display region located between the display region and the aperture region, a thin film transistor layer arranged on the flexible substrate, a light-emitting device layer arranged on the thin film transistor layer and including a first electrode, a light-emitting layer, and a second electrode, an encapsulation layer arranged on the light-emitting device layer and sequentially including a first inorganic encapsulation layer and a first organic encapsulation layer, and borders of the second electrode and the first inorganic encapsulation layer in the first non-display region are aligned, and an inorganic layer covering the borders of the second electrode and the first inorganic encapsulation layer.