Micro-LED Common Electrode Layout With Island Resin Stress Relief

Solution Overview

Problem

Micro-LED displays face issues with internal stress at the interface between electrodes and the resin layer, leading to potential peeling and breakage, which affects the reliability of the connection between the common electrode and the light emitting elements, and can result in moisture ingress.

Innovation Solution

The resin layer is provided in an island-like shape around each pixel, rather than covering the entire surface, to distribute internal stress within each pixel unit and prevent peeling of the common electrode from the resin layer, ensuring electrical connectivity and moisture sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the resin layer covers the entire surface including between pixels, then moisture sealing is improved, but internal stress concentrates at the interface causing electrode peeling and breakage

Engineering Contradiction:

Improvemoisture ingressVSAvoidelectrode connection reliability

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The resin layer is segmented into isolated island-like regions, each covering only the light emitting elements within a pixel unit. The spaces between adjacent pixels remain free of resin layer, creating distinct resin-filled regions separated by electrode-containing regions. This segmentation prevents continuous stress concentration paths while maintaining moisture sealing at critical locations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The resin layer is selectively applied only where moisture sealing is most critical (around light emitting elements), while deliberately omitted from regions where stress concentration would harm electrodes (between pixels). This local differentiation optimizes both moisture protection and mechanical reliability by placing resin only in locations with highest benefit-to-risk ratio.

Inventive Principle:

Principle #3Local quality

2Reliability

If the resin layer is provided in an island-like shape around each pixel, then internal stress is distributed and electrode peeling is prevented, but moisture sealing coverage is reduced

Engineering Contradiction:

Improvecommon electrode connection reliabilityVSAvoidmoisture ingress

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The resin layer is segmented into isolated island-like regions, each covering only the light emitting elements within a pixel unit. The spaces between adjacent pixels remain free of resin layer, creating distinct resin-filled regions separated by electrode-containing regions. This segmentation prevents continuous stress concentration paths while maintaining moisture sealing at critical locations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention converts the potentially harmful effect of stress concentration into a beneficial stress-distribution mechanism. By creating isolated resin islands separated by electrode regions, the structure uses the electrode-containing spaces as stress-relief zones, preventing stress accumulation at interfaces while maintaining overall structural integrity and moisture sealing.

Inventive Principle:

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

3Object-affected harmful factors

If a continuous resin layer is used for moisture sealing, then moisture protection is improved, but wiring resistance increases due to stress-induced electrode breakage

Engineering Contradiction:

Improvemoisture ingressVSAvoidwiring resistance

Core Design Contradiction:

Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The resin layer is segmented into isolated island-like regions, each covering only the light emitting elements within a pixel unit. The spaces between adjacent pixels remain free of resin layer, creating distinct resin-filled regions separated by electrode-containing regions. This segmentation prevents continuous stress concentration paths while maintaining moisture sealing at critical locations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The resin layer is selectively applied only where moisture sealing is most critical (around light emitting elements), while deliberately omitted from regions where stress concentration would harm electrodes (between pixels). This local differentiation optimizes both moisture protection and mechanical reliability by placing resin only in locations with highest benefit-to-risk ratio.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS12132069B2Display device

Publication Date: 2024.10.29 JAPAN DISPLAY INC

AI summary

According to one embodiment, a display device includes a substrate, a plurality of pixels, a resin layer and a common electrode. The pixels include a plurality of light emitting elements arranged on the substrate and having luminous colors different from each other, respectively. The resin layer is buried in a clearance part between the plurality of light emitting elements provided in each of the pixels. The common electrode is formed of a transparent conductive material covering the resin layer. The resin layer is provided in an island-like shape in each of the pixels.