Light Emitting Element Alignment in Display Manufacturing

Solution Overview

Problem

Current methods for manufacturing display devices are complex and require multiple masks, making them inefficient and costly, particularly when integrating ultra-small rod-like LEDs into self-emissive display devices.

Innovation Solution

A simplified method involving the formation of a substrate with a first electrode, an insulating layer, and light emitting elements, where the insulating layer is patterned to expose one end of each element, allowing for alignment and connection of a second electrode, reducing the need for additional masks and simplifying the manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple masks are used in the manufacturing process, then the alignment precision of light emitting elements can be improved, but the device complexity and manufacturing cost increase

Engineering Contradiction:

Improvealignment precisionVSAvoidprocess complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines the insulating layer formation and light emitting element placement into a single concurrent process using photoresist composition containing the light emitting elements. This merging eliminates the need for separate masks and processes, reducing device complexity while maintaining alignment precision through the alignment electrode mechanism.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The alignment electrode generates an electric field that automatically aligns the light emitting elements based on their dielectric properties, eliminating the need for external mask-based alignment systems. The system uses its own electric field to achieve precise positioning without additional complex alignment tools.

Inventive Principle:

Principle #25Self-service

2Manufacturing precision

If multiple masks are used in the manufacturing process, then the alignment precision of light emitting elements can be improved, but the manufacturing cost increases

Engineering Contradiction:

Improvealignment precisionVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent combines the insulating layer formation and light emitting element placement into a single concurrent process using photoresist composition containing the light emitting elements. This merging eliminates the need for separate masks and processes, reducing manufacturing cost while maintaining alignment precision through the alignment electrode mechanism.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The alignment electrode generates an electric field that automatically aligns the light emitting elements based on their dielectric properties, eliminating the need for external mask-based alignment systems. The system uses its own electric field to achieve precise positioning without additional costly alignment tools.

Inventive Principle:

Principle #25Self-service

3Manufacturing precision

If the insulating layer is patterned to expose only one end of light emitting elements, then the connection precision with electrodes is improved, but the manufacturing process complexity increases

Engineering Contradiction:

Improveconnection precisionVSAvoidpatterning complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The alignment electrode is positioned in advance and configured to generate an electric field that pre-aligns the light emitting elements before the insulating layer is fully patterned. This preliminary alignment action simplifies the subsequent patterning process while ensuring precise connection positioning.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The alignment electrode generates an electric field that automatically aligns the light emitting elements based on their dielectric properties, eliminating the need for external mask-based alignment systems. The system uses its own electric field to achieve precise positioning without additional costly alignment tools.

Inventive Principle:

Principle #25Self-service

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 reduces the complexity and cost of manufacturing by eliminating the need for multiple masks, improving precision and efficiency in aligning and connecting light emitting elements within the display device.

Implementation Method 1

aligning the light emitting elements may include: disposing an alignment electrode over the insulating layer; and applying power to each of the first electrode and the alignment electrode to align the light emitting elements

Methodology Applied

Scientific EffectElectrostatic alignment: Electrostatics

Data Source

PatentUS11552215B2Method of manufacturing display device and display device

Publication Date: 2023.01.10 SAMSUNG DISPLAY CO LTD

AI summary

A method of manufacturing a display device includes: forming a first electrode on a substrate; forming an insulating layer on the substrate and on the first electrode; providing light emitting elements in the insulating layer, each of the light emitting elements having a long axis and a short axis crossing the long axis and being configured to emit light; aligning the light emitting elements such that one end of each of the light emitting elements faces the substrate and the long axis of each of the light emitting elements is arranged in a direction from the substrate toward the insulating layer; patterning the insulating layer to form an insulating pattern exposing another end of each of the light emitting elements; and forming a second electrode electrically connected to the exposed other end of each of the light emitting elements.