Multilayer Display Electrode Contact Layout Against Galvanic Corrosion

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Solution Overview

Problem

Existing display devices face challenges in preventing damage to electrodes and ensuring the reliability of electrical signals, particularly due to corrosion and galvanic reactions between different materials used in the electrode layers.

Innovation Solution

The proposed solution involves a display device structure with a multi-layer electrode configuration, where a first layer and a second layer are used, with the first layer being more adjacent to the base layer and the second layer more adjacent to the light emitting element, and a connection electrode that physically contacts only the first layer through a contact portion formed in a region penetrating the insulating layers, while the second layer is kept separate to prevent corrosion. The materials for the first and second layers have different corrosion potentials, with the first layer made of molybdenum-based materials and the connection electrode made of transparent conductive materials like ITO, ensuring a potential difference of less than 1.0V to prevent galvanic corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single-layer electrode structure is used, then the device complexity is reduced, but the reliability of electrical signals deteriorates due to corrosion and galvanic reactions

Engineering Contradiction:

Improveelectrode structure complexityVSAvoidelectrical signal reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The electrode structure is segmented into multiple layers: a first electrode layer (Mo-based) adjacent to the base layer, a second electrode layer (Al-based) adjacent to the light emitting element, and a connection electrode (ITO/IZO/ITZO). This segmentation allows each layer to perform specific functions and prevents direct contact between dissimilar materials that would cause galvanic corrosion, thereby improving electrical signal reliability while maintaining manageable complexity through functional specialization.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first electrode layer (Mo-based) acts as an intermediary between the base layer and the connection electrode. By positioning this layer between the Al-based second electrode layer and the transparent conductive connection electrode, the patent prevents direct contact between materials with large potential differences, thus eliminating galvanic corrosion pathways and ensuring long-term electrical signal reliability.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If different materials with different corrosion potentials are used in electrode layers, then the functionality and performance are improved, but the risk of galvanic corrosion increases

Engineering Contradiction:

Improveelectrode material functionalityVSAvoidgalvanic corrosion risk

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies equipotentiality by ensuring that the first electrode layer (Mo-based) and the connection electrode (ITO/IZO/ITZO) have corrosion potentials that differ by 1.0V or less. This minimizes the potential difference between adjacent conductive layers, reducing the driving force for galvanic corrosion while maintaining the necessary functionality of each material layer.

Inventive Principle:

Principle #12Equipotentiality

Solution Approach 2:

Different regions of the electrode structure use materials with locally optimized properties: the first layer uses Mo-based materials for stability and low corrosion potential difference with transparent conductors, the second layer uses Al-based materials for high conductivity near the light emitting element, and the connection electrode uses transparent conductive materials for optical transparency and electrical connection. This local quality optimization allows each region to perform its specific function while minimizing overall corrosion risk.

Inventive Principle:

Principle #3Local quality

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 configuration effectively prevents electrode damage and maintains the reliability of electrical signals by controlling the corrosion potential difference between the layers, thereby reducing the risk of galvanic corrosion and excessive resistance, enhancing the overall performance and longevity of the display device.

Implementation Method 1

the corrosion potential difference between the layers, thereby reducing the risk of galvanic corrosion

Methodology Applied

Scientific EffectGalvanic corrosion:

Implementation Method 2

a connection electrode electrically connecting the light emitting element and at least a portion of the electrodes

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS20240014353A1Display device and method of manufacturing the same

Publication Date: 2024.01.11 SAMSUNG DISPLAY CO LTD

AI summary

A display device includes electrodes on a base layer; a first insulating layer on the electrodes; a light emitting element on the first insulating layer; and a connection electrode electrically connecting the light emitting element and at least a portion of the electrodes. Each of the electrodes includes a first layer and a second layer on the first layer. The first layer is electrically connected to the connection electrode through a contact portion formed in a region penetrating the first insulating layer and the second layer.