OLED Lighting Apparatus Laser Patterning Without Open Masks

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Solution Overview

Problem

The existing methods for fabricating lighting apparatuses using organic light emitting diodes (OLEDs) are complex and inefficient, requiring multiple processes and open masks that can lead to alignment issues, shadowing, and defects due to particle generation during laser processing, especially when using roll-to-roll processes.

Innovation Solution

A method and apparatus for patterning OLEDs without using open masks, employing laser processing after encapsulation to form trenches and contact holes, which simplifies the fabrication process, reduces costs, and enhances reliability by preventing moisture introduction and particle-related defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If open masks are used for patterning OLED layers during deposition, then pattern formation is achieved, but alignment errors, shadowing, and particle defects occur

Engineering Contradiction:
Improvepattern formation accuracyVSAvoiddefect rate
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The encapsulation layer is formed in advance before the patterning process. This preliminary action allows subsequent laser processing to be performed on the encapsulated structure, preventing particle contamination during patterning operations and eliminating the need for open masks that cause alignment errors and shadowing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The mechanical open mask system is replaced with a laser-based patterning method. Instead of using physical masks that require alignment and washing, laser processing directly patterns the encapsulated OLED structure, eliminating mask-related defects and simplifying the manufacturing process.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If multiple open masks are used for different layers, then each layer can be patterned separately, but the number of processes and alignment steps increases

Engineering Contradiction:
Improvelayer-by-layer patterning capabilityVSAvoidnumber of deposition chambers and masks
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The encapsulation function and the patterning function are merged into a single integrated process. The encapsulation layer serves both as a protective barrier and as a substrate for subsequent laser patterning, eliminating the need for separate mask alignment and washing processes for each layer.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The encapsulation layer performs multiple functions: it protects the OLED structure from moisture and oxygen, and simultaneously serves as a platform for laser-based patterning operations. This multi-functionality reduces the overall number of process steps and equipment required.

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

3Manufacturing precision

If laser processing is performed before encapsulation, then patterning is completed, but particles are generated and moisture can enter the device

Engineering Contradiction:
Improvepatterning accuracyVSAvoidparticle contamination and moisture ingress
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

Encapsulation is performed as a preliminary action before laser patterning. This sequence prevents particle generation during laser processing from contaminating the device interior and prevents moisture ingress during subsequent processing steps, while still achieving the required patterning accuracy.

Inventive Principle:
Principle #10Preliminary action

4Productivity

If roll-to-roll process is used for flexible substrate, then production efficiency is improved, but the number of processes increases due to mask washing and alignment

Engineering Contradiction:
Improvecontinuous production capabilityVSAvoidnumber of fabrication steps
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The mask-related processes (mask alignment, mask washing, mask replacement) are extracted and eliminated from the roll-to-roll fabrication process. By using laser patterning on encapsulated structures, the continuous production capability is maintained while the number of fabrication steps is significantly reduced.

Inventive Principle:
Principle #2Taking out (Extraction)

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 simplifies the OLED fabrication process, reduces costs, and improves reliability by eliminating the need for open masks and minimizing defects, allowing for efficient production of various models using roll-to-roll processes while ensuring uniform light emission and extended light emission efficiency.

Implementation Method 1

an organic light emitting layer (130) between the first and second electrodes

Methodology Applied
Scientific EffectOrganic light emitting diode: Organic Light-emitting Diode

Data Source

PatentEP3346499B1Lighting apparatus using organic light emitting diode and method of fabricating the same
Publication Date: 2024.09.25 LG DISPLAY CO LTD
  • EP3346499B1 patent drawingFigure 1
  • EP3346499B1 patent drawingFigure 2
  • EP3346499B1 patent drawingFigure 3

AI summary

A lighting apparatus using an organic light emitting diode and a method of fabricating the same according to the present disclosure is configured such that a contact electrode is formed using laser ablation and printing after an organic light emitting material, a conductive layer for a cathode and a passivation layer are deposited on an entire surface of a substrate, and then encapsulated with a metal film. The present disclosure simplifies a fabricating process of the lighting apparatus by virtue of a non-use of an open mask (metal mask) as a sophisticated apparatus, and particularly, can be effectively applied to a roll-producing process. Also, the present disclosure can provide an effect of improving reliability by preventing moisture permeation in a manner of covering an exposed contact portion with a protection film such as a barrier tape.