OLED Pixel Defining Layer Supporting Structures for Evaporation Masking

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In organic light emitting diode (OLED) display substrates, the evaporation process for forming organic functional layers often results in material diffusion between pixel accommodating holes, leading to poor color mixing due to the proximity of the evaporation mask to the pixel defining layer.

Innovation Solution

The implementation of supporting structures on the pixel defining layer, which are in one-to-one correspondence with the pixel accommodating holes and have orthographic projections that surround them, preventing material diffusion during the evaporation process by blocking the material from adjacent holes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the evaporation mask is placed close to the pixel defining layer during the evaporation process, then the manufacturing efficiency is improved, but material diffusion occurs between adjacent pixel accommodating holes leading to poor color mixing

Engineering Contradiction:

Improvemanufacturing efficiencyVSAvoidcolor mixing quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The pixel defining layer is segmented into multiple pixel accommodating holes, and supporting structures are introduced to further segment the evaporation zones. This segmentation prevents material diffusion between adjacent holes while maintaining close proximity of the evaporation mask to the substrate for efficient manufacturing.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Supporting structures are introduced as intermediary elements between the evaporation mask and the pixel accommodating holes. These structures act as physical barriers that block material diffusion while allowing the evaporation process to proceed efficiently with the mask positioned close to the substrate.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If supporting structures are added to prevent material diffusion, then color mixing quality is improved, but the device complexity increases

Engineering Contradiction:

Improvecolor mixing qualityVSAvoidstructure complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The supporting structures are merged with the pixel defining layer to form an integrated structure. This combination reduces device complexity by eliminating the need for separate supporting structure components while still providing the necessary function of preventing material diffusion.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The supporting structures serve multiple functions: they prevent material diffusion between adjacent pixel accommodating holes, provide structural support for the pixel defining layer, and define the boundaries of each pixel region. This multi-functionality reduces the need for additional components, thereby reducing overall device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 solution effectively prevents material diffusion between pixel accommodating holes, thereby improving color mixing and overall display quality by ensuring that the organic functional layer material remains within its designated pixel accommodating hole.

Implementation Method 1

material diffusion between pixel accommodating holes

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 2

supporting structures... preventing material diffusion during the evaporation process by blocking the material from adjacent holes

Methodology Applied

Scientific EffectPhysical containment: Physical Containment

Data Source

PatentUS11349107B2Display substrate, display device, and manufacturing method of display substrate

Publication Date: 2022.05.31 MIANYANG BOE OPTOELECTRONICS TECH CO LTD

AI summary

The present disclosure provides a display substrate, a display device, and a manufacturing method of a display substrate. The display substrate of the present disclosure includes a substrate, a pixel defining layer located on the substrate, and a plurality of organic light emitting diodes arranged in an array, with a plurality of pixel accommodating holes provided in the pixel defining layer, and the organic light emitting diodes in one-to-one correspondence with the pixel accommodating holes, and located in the corresponding pixel accommodating holes; and a plurality of supporting structures in one-to-one correspondence with the pixel accommodating holes are formed on a side of the pixel defining layer distal to the substrate, and orthographic projections of the supporting structures on the pixel defining layer surround the corresponding pixel accommodating holes.