OLED Resonance Structure via Auxiliary Electrode Segmentation

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Solution Overview

Problem

The production of full-color OLED devices is hindered by the complexity of forming organic films with different thicknesses, leading to defects and reduced yield due to the need for fine metal masks.

Innovation Solution

An OLED device with a resonance structure is developed, featuring first and second auxiliary electrode layers with different etch selectivities, where the second auxiliary electrode layers of different pixel units have varying thicknesses, made of ITO and AZO respectively, to achieve resonance effects for red, green, and blue light emission, minimizing the use of fine metal masks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If fine metal masks are used to form organic films with different thicknesses, then the luminous efficiency and brightness of different color pixels can be optimized, but the manufacturing process becomes complicated and defect rates increase

Engineering Contradiction:
Improveorganic film thickness controlVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent divides the single auxiliary electrode layer into two separate layers: a first auxiliary electrode layer (ITO) and a second auxiliary electrode layer (AZO) with different etching rates. This segmentation allows independent control of each layer's thickness through selective etching, enabling precise thickness control for different color pixels without requiring complex fine metal masks for each organic film deposition step.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary formation of the two auxiliary electrode layers with different materials and etching rates before organic film deposition. This preliminary action establishes a built-in thickness control mechanism that will be activated during the etching process, allowing subsequent organic films to be formed with different effective thicknesses without requiring separate masking steps for each pixel type.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If fine metal masks are used to form organic films with different thicknesses, then the luminous efficiency of different color pixels can be optimized, but the production yield decreases due to defects such as stains and blind spots

Engineering Contradiction:
Improveorganic film thickness controlVSAvoidproduction yield
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

By segmenting the auxiliary electrode into two layers with different etching rates, the patent eliminates the need for fine metal masks during organic film formation. This removes the source of masking-related defects (stains, blind spots) while still achieving the required thickness differentiation for optimizing luminous efficiency of red, green, and blue pixels.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second auxiliary electrode layer (AZO) acts as an intermediary that mediates the thickness control function. During etching, this layer is selectively removed at different rates compared to the first auxiliary electrode layer, creating the desired thickness variation in the organic films without requiring direct physical masks during deposition, thereby preventing mask-related defects.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If organic films with different thicknesses are formed using conventional methods, then color-specific luminous efficiency can be maximized, but the number of manufacturing steps increases

Engineering Contradiction:
Improveorganic film thickness controlVSAvoidmanufacturing throughput
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent merges the thickness control function for multiple color pixels into a single etching process. By combining the first auxiliary electrode layer (ITO) and second auxiliary electrode layer (AZO) with different etching rates, the system achieves differential thickness control for red, green, and blue pixels simultaneously during one etching step, rather than requiring separate masking and deposition steps for each color.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the material parameter of the auxiliary electrode layers, using ITO and AZO with distinctly different etching rates. This parameter change enables the etching process itself to become the thickness control mechanism, replacing multiple deposition and masking steps with a single etching operation that automatically creates the required thickness variations based on material properties.

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

This approach increases the productivity and yield of OLED devices by simplifying the manufacturing process and reducing defects, while maintaining efficient light emission across different colors.

Implementation Method 1

the second auxiliary electrode layers of the at least two of the first, second, and third pixel units respectively have different thicknesses, so that light beams emitted from the first, second and third pixel units can be provided with a resonance effect

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP2128911B1Organic light emitting display device
Publication Date: 2016.08.03 SAMSUNG DISPLAY CO LTD
  • EP2128911B1 patent drawingFigure 1
  • EP2128911B1 patent drawingFigure 2
  • EP2128911B1 patent drawingFigure 3

AI summary

An organic light emitting display (OLED) device having an organic light emission unit, the organic light emitting unit including a first electrode layer on a substrate, a second electrode layer on the first electrode layer, and an organic layer between the first electrode layer and the second electrode layer, the OLED device including a first auxiliary electrode layer between the organic layer and the first electrode layer. The organic light emission unit is divided into first, second, and third pixel units. Each of the first, second, and third pixel units includes a second auxiliary electrode layer between the organic layer and the first auxiliary electrode layer. The second auxiliary electrode layers of the first, second and third pixel units are formed to have different thicknesses respectively, so that light beams emitted from the first, second and third pixel units can be provided with a resonance effect.