Organic Light-Emitting Display Emission Layer Formation via Sacrificial Mask

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Solution Overview

Problem

Current methods for manufacturing organic light-emitting display apparatuses face challenges in preventing defect generation during the formation of emission layers and encapsulation, leading to reduced quality and increased defect rates.

Innovation Solution

The method involves using a fine metal mask (FMM) to form red, green, and blue emission layers with a patterned sacrificial layer, ensuring a constant interval and minimizing contact with the pixel definition layer and intermediate layers, while a fluorinated sacrificial layer is used to prevent damage during removal, enhancing the bonding power of the thin film encapsulation layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a fine metal mask (FMM) is used to form emission layers, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:
Improveemission layer formation precisionVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The manufacturing process is segmented into distinct stages: forming the sacrificial layer, forming emission layers in first through holes, removing the sacrificial layer, and forming encapsulation layers. This segmentation allows each stage to be optimized independently, maintaining precision while managing complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A sacrificial layer is formed in advance before emitting the emission layers. This preliminary action creates a structured template (first through holes) that guides precise emission layer formation, improving manufacturing precision while the sacrificial layer is later removed to simplify the final structure.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If the FMM contacts the pixel definition layer and intermediate layers, then ease of manufacture is improved, but reliability deteriorates due to damage risk

Engineering Contradiction:
Improveemission layer formation easeVSAvoidlayer integrity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The sacrificial layer acts as an intermediary between the FMM and the pixel definition layer/intermediate layers. It provides a protective barrier during emission layer formation, preventing direct contact and potential damage, while still allowing the FMM to function effectively for precise layer deposition.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sacrificial layer is formed beforehand to cushion and protect the underlying pixel definition layer and intermediate layers during the emission layer formation process. This prior cushioning prevents damage while maintaining manufacturing ease.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If the encapsulation layer is formed with strong bonding, then reliability is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improveencapsulation bonding strengthVSAvoidencapsulation layer formation precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The sacrificial layer is formed in advance to create precisely defined first through holes that serve as templates for emission layer placement. This preliminary structuring ensures that subsequent encapsulation layers can be formed with strong bonding while maintaining manufacturing precision through the guided hole structure.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The encapsulation process focuses on local quality enhancement at critical bonding interfaces (pixel definition layer, intermediate layers, opposite electrode) rather than requiring uniform high precision across the entire structure. The sacrificial layer removal creates localized through holes where precise bonding is most needed.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3128557B1Method of manufacturing an organic light-emitting display apparatus
Publication Date: 2022.04.13 SAMSUNG DISPLAY CO LTD
  • EP3128557B1 patent drawingFigure 1
  • EP3128557B1 patent drawingFigure 2
  • EP3128557B1 patent drawingFigure 3

AI summary

An organic light-emitting display apparatus, including a pixel electrode; a pixel definition layer covering at least a portion of an edge of the pixel electrode; an emission layer on the pixel electrode; and a first intermediate layer on the pixel electrode and the pixel definition layer, the first intermediate layer having a first through hole corresponding to at least a portion of an upper surface of the pixel definition layer.