OLED Lighting Apparatus Laser Ablation Fabrication

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Solution Overview

Problem

Conventional lighting apparatuses using incandescent and fluorescent lamps face issues with energy efficiency and color rendering index, while inorganic LEDs have low luminous efficiency in red and green wavelengths, and the use of open masks in OLED fabrication increases complexity and costs.

Innovation Solution

A lighting apparatus using an organic light-emitting diode (OLED) is fabricated without an open mask, employing a substrate with a trench around the lighting area to separate the organic emissive layer from peripheral areas, allowing for laser ablation and simplifying the process, reducing costs and equipment complexity, and enabling roll-to-roll manufacturing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If open masks are used for depositing organic emissive layer and electrodes in OLED fabrication, then deposition can be performed in high vacuum atmosphere, but the total number of processes increases and equipment complexity increases

Engineering Contradiction:
Improvedeposition qualityVSAvoidequipment complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the open mask from the deposition system, extracting the masking function to a different approach. The organic emissive layer and electrodes are deposited without masks, and patterning is achieved through alternative methods such as using the substrate structure itself or post-deposition processing, thereby simplifying the equipment while maintaining deposition quality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The deposition chamber is designed to perform multiple functions without requiring separate masking equipment. The same chamber that deposits the organic emissive layer also deposits subsequent electrodes and passivation layers without needing different masks for each layer, making the equipment more versatile and reducing overall system complexity.

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

2Ease of manufacture

If open masks are used for depositing different layers, then deposition can be performed, but cleaning process is needed at every step and alignment complexity increases

Engineering Contradiction:
Improvedeposition feasibilityVSAvoidprocess time
Core Design Contradiction:
Ease of manufactureVSLoss of time

Solution Approach 1:

The patent enables continuous deposition of multiple layers without interrupting the process for mask changes or cleaning. The deposition chamber maintains vacuum continuity, and layers are deposited sequentially without breaking the process flow, eliminating the time lost to cleaning and re-aligning masks between steps.

Inventive Principle:
Principle #20Continuity of useful action

3Manufacturing precision

If substrate and open masks are aligned for deposition, then pattern accuracy can be achieved, but misalignment creates shadow and pattern tolerance leading to defects

Engineering Contradiction:
Improvepattern accuracyVSAvoidalignment defects
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent removes the mask component entirely from the deposition system, eliminating the source of alignment errors. Without physical masks that need to be aligned with the substrate, the harmful factor of misalignment-induced defects is removed from the process.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If multiple deposition chambers are used for maintaining high vacuum for each thin film, then deposition quality is maintained, but equipment complexity and cost increase

Engineering Contradiction:
Improvedeposition qualityVSAvoidnumber of chambers
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple deposition functions into a single vacuum chamber. Instead of using separate chambers for depositing the organic emissive layer, electrodes, and passivation layers, all depositions are performed in one continuous process within the same vacuum environment, reducing equipment complexity while maintaining deposition quality.

Inventive Principle:
Principle #5Merging (Combining)

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 improves the color rendering index and luminous efficiency of the OLEDs, particularly in red and green wavelengths, and simplifies the fabrication process by eliminating the need for open masks, making it adaptable to various models and cost-effective for roll-to-roll manufacturing.

Implementation Method 1

forming a trench in the peripheral areas all around the outer perimeter of the lighting area by removing the organic emissive layer, the second electrode, and the second passivation layer from the first and second peripheral areas

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentEP3331039B1Lighting apparatus using organic light-emitting diode and method of fabricating the same
Publication Date: 2020.12.30 LG DISPLAY CO LTD
  • EP3331039B1 patent drawingFigure 1
  • EP3331039B1 patent drawingFigure 2
  • EP3331039B1 patent drawingFigure 3

AI summary

A lighting apparatus (100) using an organic light-emitting diode and a method of fabricating the same according to the present disclosure are characterized in that contact electrodes (127, 128) are formed by laser ablation and printing after an organic emissive material, a conductive film as a cathode, and passivation layers (115a, 115b) are deposited on the entire surface of a substrate (110). The lighting apparatus (100) may be fabricated in a simplified manner without using an open mask (metal mask), which is a complicated tool, and may be useful especially in roll-to-roll manufacturing.