Display Device EL Layer Patterning Without Shadow Mask
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Solution Overview
Problem
Current display technologies face challenges in achieving high-definition, low-power, high-contrast, and reliable display devices with efficient manufacturing methods, particularly in integrating light-emitting elements without the use of shadow masks, which can lead to deviations in pixel positioning and defects due to dust and material inaccuracies.
Innovation Solution
A display device structure and manufacturing method that employs fine patterning of EL layers without a shadow mask, allowing for precise control of light-emitting elements with separate EL layers for different colors, reducing the distance between adjacent layers to less than 10 μm, and using light exposure techniques to minimize non-light-emitting regions and maximize aperture ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If shadow masks are used to form EL layers, then manufacturing is easier, but pixel positioning accuracy deteriorates and defects increase due to dust and material inaccuracies
Solution Approach 1:
The patent removes the shadow mask from the manufacturing process entirely. Instead of using a shadow mask to define pixel patterns, the invention uses direct light exposure methods to form EL layers, eliminating the source of positioning errors and dust-related defects while maintaining manufacturing feasibility through alternative patterning techniques
Solution Approach 2:
The patent replaces the mechanical shadow mask system with an optical field-based approach. Instead of physically blocking light with a shadow mask, the invention uses optical fields (light exposure) to directly pattern the EL layers, substituting mechanical positioning with optical precision that is less susceptible to dust and material inaccuracies
2Ease of manufacture
If EL layers are positioned farther apart, then manufacturing is easier, but aperture ratio decreases and display definition deteriorates
Solution Approach 1:
The patent performs preliminary patterning of the substrate and formation of pixel electrodes before depositing the EL layers. This preliminary action establishes precise positional references that enable the EL layers to be positioned at optimal distances (less than 10 μm apart) while maintaining manufacturing feasibility through pre-planned fabrication sequences
Solution Approach 2:
The patent addresses the spacing issue by transitioning to a multi-layer stacked architecture where EL layers for different colors are positioned in vertical proximity (less than 10 μm apart) rather than relying on horizontal spacing. This dimensional transition allows for high aperture ratios while maintaining ease of manufacture through vertical integration
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 approach enables the creation of high-definition display devices with high aperture ratios and clear, high-contrast displays, reducing manufacturing complexities and improving reliability by eliminating the need for shadow masks and minimizing defects.
Implementation Method 1
By applying voltage to this element, light emission can be obtained from the light-emitting organic compound
Data Source
AI summary
A display device with high display quality is provided. A highly reliable display device is provided. A display device with low power consumption is provided. A display device that can easily achieve higher definition is provided. A display device with both high display quality and high definition is provided. A display device with high contrast is provided. The display device includes a first wiring to a fourth wiring and a display portion including a first pixel to a third pixel. The second pixel is positioned between the first pixel and the third pixel in a plan view. Each pixel includes a first subpixel and a second subpixel. The first wiring has a function of applying a first potential to the second subpixel included in the first pixel. The second wiring has a function of applying the first potential to the first subpixel included in the second pixel. The third wiring has a function of applying the first potential to the second subpixel included in the second pixel. The fourth wiring has a function of applying the first potential to the first subpixel included in the third pixel. The first wiring and the second wiring are adjacent to each other. The third wiring and the fourth wiring are adjacent to each other. A distance between the first wiring and the second wiring is shorter than a distance between the third wiring and the fourth wiring.