Micro-LED Display Electrode Via Structure Against Outgassing Bond Failure

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Solution Overview

Problem

During the manufacturing of micro light emitting display devices, defective bonding between the light emitting element and the electrode can occur due to outgassing from the organic layer, leading to electrical disconnection and dark spots in the pixel.

Innovation Solution

A display device structure is proposed, which includes a substrate with first and second electrodes, an organic pattern layer between them, a light emitting element with contact electrodes, and via layers connecting the electrodes to the contact electrodes. The via layers include connection holes that expose the electrodes, allowing for secure electrical connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the organic layer is processed during manufacturing, then the light emitting element can be bonded to the electrode, but outgassing occurs causing defective bonding and electrical disconnection

Engineering Contradiction:

Improvebonding reliabilityVSAvoidoutgassing

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent extracts and removes the organic layer from the manufacturing process. By eliminating the organic layer that causes outgassing, the bonding between the light emitting element and electrode can proceed without harmful gas evolution, thereby improving bonding reliability while removing the source of the harmful factor.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the potential harm of having no organic layer (which would normally provide insulation) into a benefit by using the exposed electrode structure to directly establish electrical connections. The electrode pattern itself serves both as the electrical conductor and as the bonding interface, eliminating the outgassing problem while maintaining electrical functionality.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If the light emitting element is directly bonded to the electrode, then electrical connection is achieved, but outgassing causes bonding failure and dark spots

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidbonding quality

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The organic layer is extracted from the structure to eliminate outgassing. This allows direct bonding between the light emitting element and electrode without the interference of organic material decomposition, thereby improving both electrical connection reliability and bonding quality by removing the source of manufacturing defects.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The electrode pattern is pre-formed with specific geometries (such as protrusions or extended areas) that facilitate reliable bonding before the light emitting element is attached. This preliminary structuring of the electrode ensures that when bonding occurs, the electrical connection is robust and resistant to the stresses of assembly, improving both connection reliability and bonding quality.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If via layers with connection holes are used to connect electrodes to contact electrodes, then secure electrical connections are achieved, but the device structure becomes more complex

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidvia layer structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the electrode layer with the bonding interface function. Instead of having separate electrodes and distinct via layers for connection, the electrode pattern itself is designed to provide both the electrical conduction path and the bonding surface. This integration reduces the number of separate layers and simplifies the overall device structure while maintaining reliable electrical connections.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The electrode serves multiple functions simultaneously: it provides electrical conduction, acts as a bonding interface for the light emitting element, and establishes the electrical connection to the contact electrodes. This multi-functionality eliminates the need for separate via layers in the traditional sense, reducing device complexity while maintaining connection reliability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS20250143043A1Display device and method for fabricating the same

Publication Date: 2025.05.01 SAMSUNG DISPLAY CO LTD

AI summary

A display device includes a substrate, first and second electrodes on the substrate, an organic pattern layer between the first electrode and the second electrode, a light emitting element on the organic pattern layer and having a first contact electrode and a second contact electrode on a top surface, a first via layer covering the first electrode and the second electrode and covering a portion of a side surface of the light emitting element, a first lower connection electrode connecting the first electrode and the first contact electrode on the first via layer, and a second lower connection electrode connecting the second electrode and the second contact electrode, a second via layer on the first via layer and covering a portion of a side surface of the light emitting element, and a first upper connection electrode connecting the first electrode and the first contact electrode.