Photolithography Light-Emitting Layers for High-Resolution Displays

Solution Overview

Problem

Current display apparatus manufacturing methods face challenges in achieving high-resolution, high-definition, and highly reliable displays with high luminance, particularly due to issues with light-emitting layer formation accuracy and reliability, especially when using metal masks which can result in low yield and reduced aperture ratio.

Innovation Solution

The use of a photolithography method without a shadow mask to form island-shaped light-emitting layers for each pixel electrode, combined with a color conversion layer and specific insulating layers to enhance light emission efficiency and reliability, and the strategic placement of functional layers to reduce damage and leakage currents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If metal masks are used to form light-emitting layers, then manufacturing process is simplified, but manufacturing precision and reliability deteriorate due to low yield and reduced aperture ratio

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoidlight-emitting layer formation accuracy

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention extracts and removes the metal mask from the manufacturing process entirely. Instead of using metal masks to form light-emitting layers, the patent employs a photolithography method where a light-sensitive resin layer is patterned using photomasks, and the light-emitting layer is subsequently formed only in the exposed regions. This extraction of the metal mask eliminates the associated precision and reliability problems while maintaining ease of manufacture through the photolithography process.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the mechanical metal mask system with a photolithographic system. Instead of physically blocking material deposition with a metal mask, the patent uses light-sensitive resin that is selectively exposed and developed to create patterns. This substitution of mechanical masking with photochemical patterning improves manufacturing precision and reliability while achieving the desired light-emitting layer formation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If metal masks are used for light-emitting layer formation, then manufacturing process is easier, but manufacturing yield and reliability worsen

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoiddisplay apparatus reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The invention extracts and removes the metal mask from the manufacturing process entirely. Instead of using metal masks to form light-emitting layers, the patent employs a photolithography method where a light-sensitive resin layer is patterned using photomasks, and the light-emitting layer is subsequently formed only in the exposed regions. This extraction of the metal mask eliminates the associated precision and reliability problems while maintaining ease of manufacture through the photolithography process.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the mechanical metal mask system with a photolithographic system. Instead of physically blocking material deposition with a metal mask, the patent uses light-sensitive resin that is selectively exposed and developed to create patterns. This substitution of mechanical masking with photochemical patterning improves manufacturing precision and reliability while achieving the desired light-emitting layer formation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Illumination intensity

If aperture ratio is increased for high luminance, then light emission efficiency improves, but manufacturing precision deteriorates due to metal mask limitations

Engineering Contradiction:

ImproveluminanceVSAvoidlight-emitting layer formation accuracy

Core Design Contradiction:

Illumination intensityVSManufacturing precision

Solution Approach 1:

The invention extracts and removes the metal mask from the manufacturing process entirely. Instead of using metal masks to form light-emitting layers, the patent employs a photolithography method where a light-sensitive resin layer is patterned using photomasks, and the light-emitting layer is subsequently formed only in the exposed regions. This extraction of the metal mask eliminates the associated precision and reliability problems while maintaining ease of manufacture through the photolithography process.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the mechanical metal mask system with a photolithographic system. Instead of physically blocking material deposition with a metal mask, the patent uses light-sensitive resin that is selectively exposed and developed to create patterns. This substitution of mechanical masking with photochemical patterning improves manufacturing precision and reliability while achieving the desired light-emitting layer formation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 enables the production of high-resolution display apparatus with improved reliability, increased aperture ratio, and enhanced manufacturing yield, allowing for efficient light emission with high luminance and color purity.

Implementation Method 1

The color conversion layer converts a color of light emitted from the first light-emitting device into a different color

Methodology Applied

Scientific EffectColor conversion: Fluorescence

Implementation Method 2

The use of a photolithography method without a shadow mask to form island-shaped light-emitting layers for each pixel electrode

Methodology Applied

Scientific EffectPhotolithography: Photopolymerisation

Data Source

PatentUS20230116067A1Display apparatus, display module, and electronic device

Publication Date: 2023.04.13 SEMICON ENERGY LAB CO LTD

AI summary

A high-resolution display apparatus is provided. The display apparatus includes first to third light-emitting devices, a color conversion layer, and first and second insulating layers. The first light-emitting device includes a first pixel electrode, a first light-emitting layer, and a common electrode. The second light-emitting device includes a second pixel electrode, a second light-emitting layer, and the common electrode. The third light-emitting device includes a third pixel electrode, a third light-emitting layer, and the common electrode. The first and second light-emitting layers contain the same light-emitting material. The third light-emitting material emits shorter-wavelength light than the first and second light-emitting devices. The color conversion layer overlaps with the first light-emitting device. The color conversion layer converts a color of light emitted from the first light-emitting device into a different color. The first and second insulating layers each overlap with a side surface and part of a top surface of the first light-emitting layer and a side surface and part of a top surface of the second light-emitting layer. The common electrode covers a top surface of the second insulating layer.