OLED Asymmetric Electrode Thickness for Edge Coverage

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Solution Overview

Problem

Current organic light-emitting display (OLED) manufacturing techniques face challenges in achieving high resolution and reducing defects and manufacturing costs, particularly due to issues with electrode thickness and edge coverage, which can lead to electrical short circuits and increased costs associated with using expensive fluorine-based resins and solvents.

Innovation Solution

The proposed OLED apparatus features a unique structure with varying electrode thicknesses and conductive layer configurations, including a common electrode, to enhance edge coverage and reduce the risk of electrical shorts, while employing a dry etching method and photolithography process to pattern organic functional layers without the need for expensive fluorine-based resins, thereby improving manufacturing efficiency and reducing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If uniform thickness opposing electrodes are used to cover side surfaces of organic functional layers, then edge coverage is improved, but manufacturing complexity and cost increase due to requiring precise thickness control and expensive fluorine-based resins

Engineering Contradiction:

Improveedge coverageVSAvoidelectrode structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by making the opposing electrode thickness non-uniform: thicker portions are positioned at locations corresponding to the side surfaces of organic functional layers to provide enhanced edge coverage and prevent short circuits, while thinner portions are positioned at other areas. This localized thickness variation optimizes protection where needed without uniformly increasing complexity throughout the entire electrode structure.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs asymmetry by deliberately designing the opposing electrode with asymmetric thickness distribution. The electrode structure transitions from a symmetric uniform thickness design to an asymmetric design where thickness varies across different regions, with specific thicker zones aligned with organic functional layer edges. This asymmetric configuration provides targeted edge coverage while simplifying the overall manufacturing process by eliminating the need for expensive fluorine-based resins.

Inventive Principle:

Principle #4Asymmetry

2Reliability

If thicker opposing electrodes are used to prevent electrical shorts, then reliability is improved, but manufacturing cost increases due to material usage and processing complexity

Engineering Contradiction:

Improveshort circuit preventionVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent applies partial action by providing enhanced electrode thickness only at specific critical locations (edge regions) rather than uniformly throughout. This partial thickening provides sufficient protection against short circuits at the most vulnerable areas while avoiding the excessive material usage and cost associated with uniform thickening across the entire electrode.

Inventive Principle:

Principle #16Partial or excessive action

3Manufacturing precision

If expensive fluorine-based resins and solvents are used in manufacturing, then manufacturing precision is improved, but manufacturing cost increases

Engineering Contradiction:

Improvepattern accuracyVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces expensive fluorine-based resins and solvents with conventional, cost-effective materials for the opposing electrode. By using standard electrode materials and conventional manufacturing processes, the invention achieves the required pattern accuracy and edge coverage without relying on costly specialized chemicals, thereby significantly reducing manufacturing costs while maintaining manufacturing precision.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Data Source

PatentUS10985339B2Organic light-emitting display apparatus and method of manufacturing the same

Publication Date: 2021.04.20 SAMSUNG DISPLAY CO LTD

AI summary

An organic light-emitting display (OLED) apparatus includes: a first electrode; a second electrode disposed separate from the first electrode; a pixel-defining layer covering an edge of the first electrode and an edge of the second electrode; a first organic functional layer disposed on the first electrode and the pixel-defining layer including a first emission layer; a first opposing electrode covering a top surface and enclosing an outer circumference of side surfaces of the first organic functional layer; a second organic functional layer disposed on the second electrode and the pixel-defining layer including a second emission layer; and a second opposing electrode covering a top surface and enclosing an outer circumference of side surfaces of the second organic functional layer. An area of the first opposing electrode in contact with the pixel-defining layer is greater than an area of the second opposing electrode in contact with the pixel-defining layer.