OLED Dummy Pattern Layout for Deposition Error Detection

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Solution Overview

Problem

Existing OLED display devices face challenges in accurately controlling the deposition position and amount of the light emitting layer during fabrication, leading to errors such as blurring and staining, which are difficult to detect and correct.

Innovation Solution

Incorporation of dummy patterns with aligned electrodes and a dummy layer on the substrate, allowing for real-time detection of deposition errors through light emission from the dummy layer, enabling precise alignment and adjustment of the light emitting diode placement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the light emitting layer is deposited using conventional methods, then the fabrication process is completed, but deposition position errors and range errors occur leading to blurring and staining defects

Engineering Contradiction:
Improvedeposition position accuracyVSAvoiddetection of deposition errors
Core Design Contradiction:
Manufacturing precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies preliminary action by forming dummy patterns (dummy pixel electrodes, dummy common electrodes, and dummy light emitting layers) before the actual light emitting layer deposition. These dummy patterns serve as pre-positioned reference structures that enable real-time detection of deposition errors. The dummy patterns are formed in advance with known positions and dimensions, allowing comparison with the actual deposited light emitting layer to detect any position or range errors immediately during fabrication.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using the dummy patterns as reference standards to detect deposition errors in real-time. After depositing the light emitting layer, the system compares the actual deposition results with the predetermined dummy patterns to identify position errors and range errors. This feedback mechanism allows for immediate detection of blurring and staining defects, enabling corrective actions to be taken during the fabrication process rather than discovering defects only after completion.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If dummy patterns are incorporated for error detection, then deposition errors can be detected in real-time, but the device structure becomes more complex

Engineering Contradiction:
Improvedetection of deposition errorsVSAvoidstructure with dummy patterns
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies the taking out principle by separating the detection function from the main display function. The dummy patterns are extracted as distinct reference structures that are spatially separated from the active pixel regions. These dummy patterns are positioned in non-display areas or in dedicated test regions, allowing them to serve as standalone reference standards without interfering with the normal display operation. This separation enables independent detection and measurement functions while maintaining the integrity of the display device.

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

The method allows for immediate detection and correction of deposition errors, enhancing fabrication stability and reducing defects in the OLED display device.

Implementation Method 1

detecting a disposition state of the light emitting diode includes detecting an error according to an emission of light from the at least one dummy layer by applying a voltage to the first electrode and the second electrode of the at least one dummy pattern

Methodology Applied
Scientific EffectLuminescence: Luminescence

Data Source

PatentEP4188056B1Organic light emitting diode display device and method of fabricating the same
Publication Date: 2026.02.25 LG DISPLAY CO LTD
  • EP4188056B1 patent drawingFigure 1~2
  • EP4188056B1 patent drawingFigure 3
  • EP4188056B1 patent drawingFigure 4A~4B

AI summary

An organic light emitting diode display device (100) includes a substrate (110); a plurality of driving elements (130) and a plurality of light emitting diodes (160) on the substrate (110); and at least one dummy pattern (170) on the substrate (110) and including a first electrode (171), a dummy layer (172), and a second electrode (173), wherein the first electrode (171) and the dummy layer (172) are separated from each other in a plan view in an arrangement without an alignment error, and wherein the first electrode (171) includes a first opening, and the dummy layer (172) is disposed in the first opening.