OLED Display Triple-Layer Emission With Single-Chamber Deposition

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Solution Overview

Problem

The fabrication process of organic light emitting diode (OLED) display devices is complicated due to the use of two independent chambers for forming multiple emitting material layers, leading to contamination and misalignment issues, which affect efficiency and productivity.

Innovation Solution

The formation of triple layered emitting material layers of a first, second, and third host and dopant is achieved in a single chamber using specific evaporation sources and shutters, allowing for sequential deposition of hosts and dopants in separate regions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two independent chambers are used to form multiple emitting material layers, then the emitting material layers can be formed with separate processing, but the fabrication process becomes complicated and contamination occurs

Engineering Contradiction:

Improveemitting material layer qualityVSAvoidfabrication process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the formation of multiple emitting material layers into a single chamber environment. The first, second, and third emitting material layers are formed sequentially in one chamber using multiple evaporation sources, eliminating the need to transfer substrates between chambers and preventing contamination that would occur during transfers.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent segments the evaporation chamber into multiple regions with separate evaporation sources positioned at different locations. Each evaporation source can deposit its material onto the substrate in a controlled manner, allowing formation of different emitting material layers with distinct hosts and dopants without interfering with each other.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If two independent chambers are used for emitting material layer formation, then processing flexibility is maintained, but misalignment of fine metal masks occurs

Engineering Contradiction:

Improveprocessing flexibilityVSAvoidfine metal mask alignment

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

By combining all emitting material layer formations in a single chamber, the patent eliminates substrate transfers that cause misalignment. The fine metal masks remain in fixed positions throughout the process, ensuring precise alignment between layers while maintaining processing flexibility through sequential deposition control.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If multiple emitting material layers are formed using separate chambers, then each layer can be optimized independently, but productivity decreases

Engineering Contradiction:

Improveemitting material layer optimizationVSAvoidfabrication productivity

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent implements continuous formation of multiple emitting material layers in a single chamber without interrupting the substrate position. The substrate remains stationary while multiple evaporation sources sequentially deposit their materials, eliminating transfer time and maximizing productivity while maintaining layer optimization.

Inventive Principle:

Principle #20Continuity of useful action

4Productivity

If a single chamber is used to form triple layered emitting material layers, then efficiency and productivity improve, but the chamber requires multiple evaporation sources and shutters

Engineering Contradiction:

Improvefabrication productivityVSAvoidchamber structure complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent divides the single chamber into multiple functional regions with separate evaporation sources positioned at different locations. Each source has its own shutter control, allowing independent operation of each material deposition process while maintaining a unified chamber structure that improves productivity.

Inventive Principle:

Principle #1Segmentation

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 method improves efficiency and simplifies the fabrication process by preventing contamination and misalignment, enhancing electron mobility and emission efficiency while reducing process complexity.

Implementation Method 1

a first emitting material layer by depositing the first host and the dopant of the first and third evaporation sources on the substrate

Methodology Applied

Scientific EffectPhysical Vapour Deposition: Physical Vapour Deposition

Data Source

PatentUS12419154B2Organic light emitting diode display device including multiple emitting material layer and method of fabricating the same

Publication Date: 2025.09.16 LG DISPLAY CO LTD

AI summary

An organic light emitting diode display device includes a substrate having a plurality of subpixels; and an emitting material layer in the plurality of subpixels on the substrate, wherein the emitting material layer in at least one of the plurality of subpixels comprises: a first emitting material layer including a first host and a dopant; a second emitting material layer on the first emitting material layer and including a second host and the dopant; and a third emitting material layer on the second emitting material layer and including one of the dopant and the second host.