Self-Emissive Alignment Mark for Organic EL Display

Solution Overview

Problem

The manufacturing process of organic EL display devices is complicated due to the need for external light irradiation and camera recognition of alignment marks, which increases complexity and reduces alignment accuracy.

Innovation Solution

An organic EL display device design featuring a first substrate with a light-emitting layer and a second substrate with a corresponding alignment mark, where the alignment mark is positioned in a non-display area and formed as an opening in a light-impermeable film, allowing for internal light emission and alignment without external light sources, thereby simplifying the manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If alignment marks are disposed on both substrates and external light irradiation is used for recognition, then alignment can be performed, but the manufacturing process becomes complicated

Engineering Contradiction:

Improvealignment accuracyVSAvoidmanufacturing process complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The alignment mark on the first substrate is configured to emit light by itself through its light-emitting layer, eliminating the need for external light irradiation devices. This self-luminous property allows the alignment mark to serve its own illumination needs, simplifying the manufacturing process while maintaining alignment accuracy.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces the optical illumination system (external light sources and cameras) with an electrical excitation system. By applying voltage to the light-emitting layer of the alignment mark, light is generated through electroluminescence, substituting the need for external optical equipment and simplifying the overall manufacturing system.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If alignment marks are disposed on both substrates and external light irradiation is used for recognition, then alignment can be performed, but alignment accuracy is reduced

Engineering Contradiction:

Improvealignment process simplicityVSAvoidalignment accuracy

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The alignment mark on the first substrate is configured to emit light by itself through its light-emitting layer, eliminating the need for external light irradiation devices. This self-luminous property allows the alignment mark to serve its own illumination needs, simplifying the manufacturing process while maintaining alignment accuracy.

Inventive Principle:

Principle #25Self-service

3Area of stationary object

If the non-display area is made narrower to improve display area ratio, then display efficiency increases, but alignment mark recognition becomes difficult

Engineering Contradiction:

Improvedisplay area ratioVSAvoidalignment mark recognition difficulty

Core Design Contradiction:

Area of stationary objectVSDifficulty of detecting and measuring

Solution Approach 1:

The alignment mark on the first substrate is configured to emit light by itself through its light-emitting layer, eliminating the need for external light irradiation devices. This self-luminous property allows the alignment mark to serve its own illumination needs, simplifying the manufacturing process while maintaining alignment accuracy.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The alignment mark region is given special local properties by incorporating a light-emitting layer that can be electrically excited to emit light. This local luminescent quality enables the alignment mark to be clearly recognized even in a narrow non-display area, as the emitted light provides high contrast and visibility without requiring external illumination.

Inventive Principle:

Principle #3Local quality

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 configuration simplifies the manufacturing process, enhances alignment accuracy, and allows for a narrower non-display area, reducing the risk of color mixture defects and enabling high-precision bonding between substrates.

Implementation Method 1

a first alignment mark having the light-emitting layer is disposed between the non-display area and the first substrate

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS9024525B2Organic luminescent display device and method of manufacturing at organic luminescent display device

Publication Date: 2015.05.05 MAGNOLIA WHITE CORP

AI summary

An organic EL display device of the invention includes: a first substrate; a second substrate disposed above the first substrate and having a display area and a non-display area; and a light-emitting layer disposed between the display area and the first substrate, wherein a first alignment mark having the light-emitting layer is disposed between the non-display area and the first substrate, and a second alignment mark is disposed on the second substrate at a position corresponding to the first alignment mark.