Micro LED Display Panel Absorption Layer for Defective Pixel Compensation

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Solution Overview

Problem

Micro LED display panels face issues with defective pixels due to manufacturing defects, which can lead to damage to the substrate, foreign substances on electrode pads, and electro-static discharge, affecting contrast ratio and turn-on yield.

Innovation Solution

A method of manufacturing a display panel involving forming a driving circuit and electrodes with distinct areas, mounting a first micro LED on one area, an absorption layer on another to absorb external light, and replacing the micro LED if defective with a second micro LED of the same color, ensuring electronic connection and minimizing electrode exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If micro LEDs are removed and replaced to compensate defective pixels, then pixel functionality is improved, but substrate damage and foreign substance contamination may occur

Engineering Contradiction:

Improvepixel functionalityVSAvoidsubstrate damage and foreign substance contamination

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by pre-forming an absorption layer on the electrode pad before mounting the micro LED. This absorption layer is prepared in advance to cover the electrode pad, preventing foreign substance contamination and substrate damage before they can occur during subsequent removal and replacement operations. The absorption layer serves as a protective measure that is already in place before the defective pixel compensation process begins.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If micro LEDs are removed to replace defective ones, then defective pixels are compensated, but turn-on yield rate decreases

Engineering Contradiction:

Improvedefective pixel compensationVSAvoidturn-on yield rate

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The absorption layer is formed in advance on the electrode pad before the micro LED mounting process. This preliminary preparation ensures that when micro LEDs are removed and replaced, the electrode pad remains protected and clean, maintaining high turn-on yield rate. The absorption layer is ready to prevent contamination immediately, eliminating delays and rework that would reduce productivity.

Inventive Principle:

Principle #10Preliminary action

3Ease of repair

If electrode pad is exposed after micro LED removal, then replacement is possible, but contrast ratio degrades due to external light reflection

Engineering Contradiction:

Improvemicro LED replacementVSAvoidcontrast ratio

Core Design Contradiction:

Ease of repairVSIllumination intensity

Solution Approach 1:

The absorption layer acts as an intermediary between the electrode pad and the external environment. It allows the electrode pad to remain exposed for electrical connection while simultaneously preventing external light from reaching and reflecting off the electrode pad surface. This intermediary layer solves the contradiction by enabling both replacement access and optical performance maintenance.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the potentially harmful effect of an exposed electrode pad (which would cause light reflection and contrast ratio degradation) into a beneficial situation. By forming an absorption layer that absorbs external light, the previously harmful exposed electrode pad becomes optically invisible, preventing contrast ratio degradation while still allowing electrical connection for micro LED replacement.

Inventive Principle:

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

4Ease of repair

If electrode pad is exposed after micro LED removal, then replacement can proceed, but electro-static discharge problems occur

Engineering Contradiction:

Improvemicro LED replacementVSAvoidelectro-static discharge

Core Design Contradiction:

Ease of repairVSObject-generated harmful factors

Solution Approach 1:

The absorption layer is formed in advance on the electrode pad before micro LED removal. This preliminary protective measure prevents electro-static discharge by covering the exposed electrode pad surface, eliminating the need for special ESD precautions during the replacement process while still allowing easy repair access.

Inventive Principle:

Principle #10Preliminary action

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 approach effectively compensates for defective pixels, enhances contrast ratio, and reduces electro-static discharge occurrences by maintaining pixel functionality and preventing electrode exposure.

Implementation Method 1

forming an absorption layer on the second area, the absorption layer configured to absorb an external light

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentUS11430705B2Display panel and method of manufacturing thereof

Publication Date: 2022.08.30 SAMSUNG ELECTRONICS CO LTD

AI summary

A display panel and a method of manufacturing thereof are provided. The method of manufacturing a display panel includes forming a driving circuit on a substrate; forming an electrode, including a first area and a second area therewith, on the driving circuit; mounting a first micro Light Emitting Diode (LED), for forming a sub pixel, on the first area; forming an absorption layer on the second area, the absorption layer configured to absorb an external light; removing, based on the sub pixel being defective, the absorption layer; and mounting a second micro LED on the second area after removing the absorption layer.