Positioning Mask Conduits for Precise Micro-LED Transfer

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Solution Overview

Problem

The existing methods for manufacturing optoelectronic devices with high-resolution light-emitting diodes face challenges in precise alignment and multi-color element transfer due to the need for high precision and the complexity of thermocompression techniques, especially when dealing with non-planar substrates and increased miniaturization.

Innovation Solution

A positioning mask with conduits of varying dimensions and shapes is used to facilitate the precise positioning of semiconductor objects on a light-emitting display substrate, allowing for easier alignment and transfer without requiring precise positioning on the reception face, and can be adapted for industrial-scale production using polymer or metallic materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If thermocompression method is used for flip-chip technique, then light-emitting diodes can be transferred onto reception support, but alignment precision deteriorates and manufacturing complexity increases

Engineering Contradiction:
Improvealignment precisionVSAvoidmanufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent introduces a positioning mask as an intermediary element between the light-emitting diodes and the reception support. This mask contains precisely positioned openings that guide the LEDs during transfer, eliminating the need for high-precision alignment between the LEDs and the final substrate. The positioning mask absorbs the alignment complexity, allowing simpler transfer processes.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The positioning mask is prepared in advance with precisely positioned openings before the transfer process begins. This preliminary preparation of the mask structure enables subsequent simple transfer operations without requiring complex real-time alignment procedures, thus reducing manufacturing complexity while maintaining precision.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If multiple successive transfer stages are used for multi-color light elements, then color diversity is achieved, but process complexity and risk of damage increase

Engineering Contradiction:
Improvecolor diversityVSAvoidprocess complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges multiple transfer operations into a single simultaneous transfer process. Different colored light-emitting diodes are transferred together in one operation using the positioning mask, rather than requiring separate transfer stages for each color. This reduces process complexity and minimizes the risk of damage from repeated handling.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If compression force is applied during thermocompression transfer, then light-emitting diodes are secured to substrate, but previously transferred diodes may be damaged

Engineering Contradiction:
Improvetransfer reliabilityVSAvoiddamage risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The positioning mask segments the transfer process by providing individual openings for each light-emitting diode position. This segmentation allows controlled transfer of each LED through its designated opening, enabling the application of compression force only where needed and preventing damage to previously transferred diodes that are not in the transfer path.

Inventive Principle:
Principle #1Segmentation

4Manufacturing precision

If high precision alignment is required for increasing resolution, then display quality improves, but manufacturing difficulty increases

Engineering Contradiction:
Improvealignment precisionVSAvoidmanufacturing difficulty
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The positioning mask serves as a mediator that decouples the precision requirement from the manufacturing process. The mask itself is manufactured with high precision, but this precision is built into the mask structure rather than requiring high-precision alignment during the transfer process. This allows standard manufacturing equipment to achieve the required precision through the mask's pre-positioned openings.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3937215B1Positioning mask, system and method for manufacturing an optoelectronic device
Publication Date: 2023.10.18 ALEDIA INC
  • EP3937215B1 patent drawingFigure 1~2
  • EP3937215B1 patent drawingFigure 3~4
  • EP3937215B1 patent drawingFigure 5~6

AI summary

The invention relates to a positioning mask (20) comprising a body delimiting a plurality of channels (25) each sized to accommodate a single functional electronic object (3) and opening through a first opening (27) onto a cooperation face (21), and through a second opening (29) onto a receiving face (23). The invention also relates to a system for manufacturing an optoelectronic device (1) comprising a plurality of functional electronic objects (3) distributed and fixed on a receiving face (12) of a screen substrate (10).The system further comprises a positioning mask (20) of the aforementioned type, a power supply unit (30) for freely depositing a set of functional electronic objects (3) onto the receiving face (23), and a placement unit (50) for positioning the cooperation face (21) opposite the receiving face (12), the conduits (25) being arranged at predetermined locations on the receiving face (12) where the functional electronic objects (3) are positioned. The invention also relates to a method for manufacturing an optoelectronic device.