Shadow Mask-Free OLED Manufacturing via UV-Patterned Interlayer

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Solution Overview

Problem

Conventional shadow mask methods for manufacturing large-scale organic light emitting display devices face issues such as deflection, pattern failure, and high raw material consumption, which hinder efficient production and yield.

Innovation Solution

A method for manufacturing organic light emitting display devices that involves forming an interlayer with hydrophilic and hydrophobic regions on top of a hole injection layer, using a solution process without a shadow mask, and selectively patterning the interlayer using UV irradiation to enable precise alignment and deposition of subsequent layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a shadow mask is used for deposition of the light emitting layer, then the light emitting layer can be patterned, but the shadow mask deflects due to its heavy weight causing pattern failure

Engineering Contradiction:
Improvepattern formation accuracyVSAvoidpattern formation reliability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent removes the shadow mask from the deposition system entirely, extracting the problematic component that caused deflection and pattern failure. Instead of using a shadow mask for patterning, the invention employs a solution process where the organic light emitting layer is deposited as a solution and then patterned through selective removal or activation, eliminating the mechanical shadow mask and its associated reliability issues.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical shadow mask system with a chemical/solution-based patterning approach. The light emitting layer is deposited using solution processing methods, and patterning is achieved through chemical means such as selective dissolution, photolithography, or self-organization, substituting the mechanical shadow mask with a chemical field-based system that does not suffer from weight-induced deflection.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If a shadow mask is used for deposition, then the light emitting layer can be formed, but raw material consumption is high

Engineering Contradiction:
Improvelight emitting layer formationVSAvoidraw material consumption
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent changes the deposition parameters from vacuum evaporation (shadow mask method) to solution processing. This parameter change allows for more efficient material utilization because solution-based deposition enables better control over material distribution, reduced material waste, and the possibility of using less expensive organic materials that can be processed from solution rather than requiring high-vacuum evaporation.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If a shadow mask is used for large-scale device manufacturing, then deposition can be performed, but the shadow mask causes deflection and repetitive use becomes difficult

Engineering Contradiction:
Improvedeposition capabilityVSAvoidshadow mask repeatability
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent extracts and removes the shadow mask component entirely from the manufacturing process, replacing it with a shadow mask-free deposition and patterning system. This elimination of the reusable mechanical component solves the problem of shadow mask deflection and difficulty in repetitive use, as the solution-based process does not rely on a heavy mechanical mask that must be repeatedly positioned and reused.

Inventive Principle:
Principle #2Taking out (Extraction)

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 approach enhances processing efficiency, prevents pattern failures, and improves yield by allowing precise alignment and deposition of layers without the need for a shadow mask, suitable for large-scale production.

Implementation Method 1

UV irradiating the interlayer to define a hydrophilic region on the interlayer

Methodology Applied
Scientific EffectPhotopolymerisation: Photopolymerisation

Data Source

PatentEP2202817B1Method for manufacturing an organic light emitting display device
Publication Date: 2016.06.29 LG DISPLAY CO LTD
  • EP2202817B1 patent drawingFigure 1
  • EP2202817B1 patent drawingFigure 2~3
  • EP2202817B1 patent drawingFigure 4A~4C

AI summary

Disclosed are an organic light emitting display device with improved yield and processing efficiency, which includes an interlayer (202) capable of being separated into a hydrophilic region (203) and a hydrophobic region on top of a hole injection layer (201) in an organic light emitting device and a plurality of layers including a light emitting layer (204) and which is fabricated without using a shadow mask, as well as a method for manufacturing the same. The manufacturing method includes preparing a substrate having a plurality of pixel regions defined in a matrix form, arranging an anode (200) in each of the pixel regions, forming a hole injection layer (201) on the anode (200) by the solution process, forming an interlayer (202) with hydrophobic properties on the hole injection layer (201) by a solution process, selectively UV irradiating the interlayer (202) to define a hydrophilic region (203) on the interlayer, forming a light emitting layer (204) on the interlayer (202) by the solution process, and arranging a cathode (206) on the substrate having the light emitting layer (204).