Color-Conversion Display Pixel Layout With Fewer Fabrication Masks

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Solution Overview

Problem

Existing display devices face challenges in achieving improved reliability and reduced production costs, particularly in the complexity and number of masks required in their fabrication processes.

Innovation Solution

A display device is designed with a substrate and a pixel that includes an emission area and a non-emission area. The pixel features a light emitting element with organic transmission and color conversion layers, utilizing light diffusion particles and color conversion particles to enhance light emission and color conversion, respectively. This configuration simplifies the fabrication process by reducing the number of masks needed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple masks are used in the fabrication process to achieve precise patterning, then manufacturing precision is improved, but device complexity and production cost increase

Engineering Contradiction:
Improvepatterning precisionVSAvoidfabrication process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple patterning functions into a single mask structure. The mask includes a first mask pattern for defining the emission area and a second mask pattern for defining the non-emission area, both formed on the same mask substrate. This merging of multiple patterning steps into one mask reduces the total number of masks required and simplifies the fabrication process while maintaining precise patterning control.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single mask structure serves multiple functions simultaneously: it defines both the emission area boundaries and the non-emission area boundaries, acts as a alignment reference for subsequent processing steps, and controls the formation of multiple pixel structures. This multi-functionality reduces the overall number of masks and processing steps required.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Manufacturing precision

If multiple masks are used in the fabrication process, then manufacturing precision is improved, but production cost increases

Engineering Contradiction:
Improvepatterning precisionVSAvoidproduction cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent combines multiple patterning functions into a single mask structure. The mask includes a first mask pattern for defining the emission area and a second mask pattern for defining the non-emission area, both formed on the same mask substrate. This merging of multiple patterning steps into one mask reduces the total number of masks required and simplifies the fabrication process while maintaining precise patterning control.

Inventive Principle:
Principle #5Merging (Combining)

3Illumination intensity

If the organic transmission layer thickness is increased to improve light diffusion, then light emission quality is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvelight emission qualityVSAvoidlayer thickness control
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent specifies a particular thickness range for the organic transmission layer (1.5 μm or more and less than 2.5 μm) to optimize light diffusion while maintaining manufacturability. This parameter optimization ensures that the layer is thick enough to provide adequate light diffusion and emission quality, but not so thick as to create excessive manufacturing difficulty or precision requirements.

Inventive Principle:
Principle #35Parameter changes

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 proposed display device achieves improved reliability and reduced production costs through a simplified fabrication process that eliminates the need for multiple masks, while also enhancing light emission and color conversion efficiency.

Implementation Method 1

an organic transmission layer covering the first end and the second end of the light emitting element, the organic transmission layer including a light diffusion particle

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 2

a color conversion layer on the organic transmission layer, the color conversion layer including a color conversion particle to convert a first color of light emitted from the light emitting element to a second color of light

Methodology Applied
Scientific EffectColor conversion: Fluorescence

Data Source

PatentEP4553904A1Display device and manufacturing method therefor
Publication Date: 2025.05.14 SAMSUNG DISPLAY CO LTD
  • EP4553904A1 patent drawingFigure 1
  • EP4553904A1 patent drawingFigure 2
  • EP4553904A1 patent drawingFigure 3

AI summary

A display device may include: a substrate; and a pixel on the substrate, and including an emission area and a non-emission area. The pixel may include: a light emitting element in the emission area, the light emitting element including a first end and a second end; a first pixel electrode electrically connected to the first end of the light emitting element; a second pixel electrode electrically connected to the second end of the light emitting element; an organic transmission layer covering the first end and the second end of the light emitting element, organic transmission layer including a light diffusion particle; and a color conversion layer on the organic transmission layer, the color conversion layer including a color conversion particle to convert a first color of light emitted from the light emitting element to a second color of light.