Micro LED Display Integration to Eliminate Transfer Bottlenecks

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Solution Overview

Problem

The transfer process of micro LEDs in display devices is time-consuming and prone to connection failures, leading to reduced yield and efficiency.

Innovation Solution

A manufacturing method that integrates light-emitting elements directly on a glass substrate with a TFT, using a conductive layer and vias to connect them to the drive circuit, reducing the need for sequential transfer and improving yield.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If micro LEDs are individually formed and sequentially transferred to the substrate, then the display device can achieve high brightness and wide viewing angle, but the transfer process takes significant time and may cause connection failure

Engineering Contradiction:
Improveconnection reliabilityVSAvoidtransfer process time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent merges the light-emitting element formation process with the substrate processing by growing the semiconductor layer including light-emitting elements directly on the same substrate where drive circuits are formed, eliminating the need for separate sequential transfer operations and reducing connection failures

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent performs preliminary formation of the semiconductor layer with light-emitting elements on the substrate before finalizing the drive circuit connections, allowing integrated processing and reducing subsequent transfer operations

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If a large number of micro LEDs are individually transferred to achieve full HD, 4K, and 8K resolution, then image quality improves, but the manufacturing time increases significantly

Engineering Contradiction:
Improveimage qualityVSAvoidmanufacturing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent combines multiple processing operations into a single integrated flow where the semiconductor layer containing multiple light-emitting elements is formed directly on the substrate with drive circuits, enabling simultaneous processing of numerous elements and significantly improving manufacturing efficiency while maintaining high image quality

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If sequential transfer method is used for micro LEDs, then individual element placement is achieved, but connection failure between micro LED and drive circuit occurs

Engineering Contradiction:
Improveelement placementVSAvoidconnection reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent merges the light-emitting element formation and drive circuit integration into a single substrate-based process, eliminating the mechanical transfer step that causes connection failures while maintaining precise element placement through controlled semiconductor layer growth and patterning

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4040511B1Image display device manufacturing method and image display device
Publication Date: 2025.10.08 NICHIA CORP
  • EP4040511B1 patent drawingFigure 1
  • EP4040511B1 patent drawingFigure 2A~2B
  • EP4040511B1 patent drawingFigure 3

AI summary

Object To provide an image display device manufacturing method that reduces a transfer process of a light-emitting element and improves yield. Solution An image display device manufacturing method according to an embodiment includes preparing a first substrate including a circuit including a circuit element formed on a light-transmitting substrate and a first insulating film covering the circuit, forming on the first insulating film a conductive layer including a portion of a single crystal metal, forming on the portion a semiconductor layer including a light-emitting layer, etching the semiconductor layer to form a light-emitting element, forming a second insulating film covering the conductive layer, the light-emitting element, and the first insulating film, forming a via passing through the first insulating film and the second insulating film, and electrically connecting the light-emitting element and the circuit element through the via at a light-emitting surface facing a surface of the light-emitting element on a side of the first insulating film.