Transfer Mask Openings for Precise Micro LED Cell Alignment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing transfer devices struggle to effectively transfer micro LEDs onto display panel substrates regardless of the varying shapes and sizes of cell areas in display panels.

Innovation Solution

A mask and transfer device are designed with a base layer and adhesive layer that define openings corresponding to cell areas, allowing for the transfer of light emitting elements using laser-induced forward transfer (LIFT) or laser lift-off (LLO) methods, with the mask having openings that match the shape and size of the cell areas, and a transfer device comprising a light source, upper and lower stages, and a mask to facilitate precise placement of light emitting elements on the target substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional transfer device is used, then the transfer process can be performed, but it cannot effectively transfer micro LEDs onto display panel substrates regardless of the varying shapes and sizes of cell areas

Engineering Contradiction:
Improveadaptability to varying cell area shapesVSAvoidtransfer precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The mask is divided into multiple openings, each corresponding to a specific cell area shape. This segmentation allows the transfer device to handle different cell area configurations by selecting appropriate mask patterns, thereby improving adaptability while maintaining transfer precision for each specific shape.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The mask structure is designed with adjustable parameters including opening size, shape, and position. By changing these parameters according to different cell area requirements, the system achieves high adaptability while preserving manufacturing precision through optimized parameter selection for each specific application.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the mask openings are made to match the exact shape and size of cell areas, then transfer precision is improved, but the device complexity increases

Engineering Contradiction:
Improvealignment precisionVSAvoidmask design complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The mask is designed as a universal component that can accommodate multiple cell area shapes and sizes through a set of standardized opening patterns. This multi-functionality allows a single mask design to serve various transfer precision requirements without increasing overall device complexity, as the same mask structure can be reused across different applications.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Manufacturing precision

If the mask is disposed in contact with the target substrate, then transfer precision is improved, but the ease of operation decreases

Engineering Contradiction:
Improvetransfer precisionVSAvoidmask handling ease
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The mask serves as an intermediary component between the transfer device and the target substrate. By maintaining controlled contact through this intermediary element, the system achieves high transfer precision while the mask itself can be easily handled and positioned by the transfer device, thus resolving the contradiction between precision and operational ease.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The solution enables effective transfer of light emitting elements onto target substrates regardless of the shape of the cell area, ensuring precise alignment and efficient use of laser beams for uniform distribution of light emitting elements across the display panel.

Implementation Method 1

irradiating a light source to an interface between the transfer substrate and the plurality of light emitting elements disposed on the transfer substrate to transfer the plurality of light emitting elements onto the target substrate

Methodology Applied
Scientific EffectLaser-induced forward transfer (LIFT): Laser Ablation

Implementation Method 2

The light source portion may irradiate the laser beam using a laser-induced forward transfer (LIFT) method or a laser lift-off (LLO) method

Methodology Applied
Scientific EffectLaser lift-off (LLO): Laser Ablation

Data Source

PatentEP4626187A1Mask, transfer device and transfer method using the same
Publication Date: 2025.10.01 SAMSUNG DISPLAY CO LTD
  • EP4626187A1 patent drawingFigure 1
  • EP4626187A1 patent drawingFigure 2
  • EP4626187A1 patent drawingFigure 3

AI summary

The present disclosure includes a mask, a transfer device, and a transfer method using the same. The mask includes a base layer configured to be disposed on a target substrate and defining a plurality of openings therein arranged in a first direction and a second direction crossing the first direction and an adhesive layer disposed on the base layer and configured to face a transfer substrate, where the plurality of openings defines a transfer area of the target substrate.