Display Apparatus Light-Emitting Layer Alignment via Maskless Etching
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Solution Overview
Problem
The manufacturing of high-resolution display apparatuses using organic EL devices faces challenges such as deviations in the shape and position of island-shaped light-emitting layers due to inaccuracies in metal masks, leading to reduced yield and increased initial investment for equipment, especially in large-scale production.
Innovation Solution
A display apparatus structure comprising multiple light-emitting devices with aligned conductive and insulating layers, where the insulating layers cover side surfaces and the common electrode is positioned over these layers, allowing for precise alignment and uniform thickness of island-shaped light-emitting layers without the need for metal masks, enabling high-resolution and high-aperture ratio displays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If a vacuum evaporation method using a metal mask is used to form island-shaped light-emitting layers, then the light-emitting layers can be formed with defined shapes and positions, but the manufacturing precision deteriorates due to deviations caused by low accuracy of metal mask position, positional deviation between mask and substrate, mask warp, and vapor-scattering-induced expansion
Solution Approach 1:
The patent removes the metal mask from the vacuum evaporation process entirely. Instead of using a mask to define the pattern, the light-emitting layer is deposited over the entire substrate and then selectively removed in non-emission regions through etching or other removal processes, leaving island-shaped light-emitting layers with high precision defined by the electrode patterns below
Solution Approach 2:
The patent inverts the traditional approach by forming the light-emitting layer continuously first and then removing material to create the island shape, rather than trying to deposit material only in the desired island regions. This inversion eliminates mask-related precision issues and allows the electrode patterns to serve as the defining structure
2Shape
If a vacuum evaporation method using a metal mask is used, then light-emitting layers can be formed, but the aperture ratio deteriorates due to vapor-scattering-induced expansion of the deposited film outline and blurring during vapor deposition
Solution Approach 1:
The patent eliminates the metal mask that causes vapor scattering and outline expansion. By depositing the light-emitting layer without a mask and then selectively removing it, the method achieves sharp outlines and maximizes the aperture ratio since the light-emitting layer can be formed exactly over the electrode area without mask-induced blurring
Solution Approach 2:
The patent replaces the mechanical mask system with a chemical or plasma-based removal process. The light-emitting layer is removed in non-emission regions through etching or other removal processes, achieving precise definition without the physical constraints and vapor scattering associated with metal masks
3Shape
If metal masks are used in vacuum evaporation, then island-shaped light-emitting layers can be formed, but the productivity deteriorates due to regular cleaning requirements that stop the process and require multiple manufacturing equipment lines
Solution Approach 1:
The patent removes the metal mask from the process entirely, eliminating the need for regular cleaning and maintenance. The island shape is achieved through selective removal of the light-emitting layer rather than through mask-defined deposition, allowing continuous manufacturing without equipment downtime for mask maintenance
Solution Approach 2:
The patent enables continuous manufacturing by eliminating the mask cleaning interruption. The light-emitting layer is deposited continuously over the entire substrate and then selectively removed, allowing the vacuum evaporation process to run continuously without stopping for mask maintenance, thereby improving productivity
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 enables the production of high-resolution, high-definition, and reliable display apparatuses with improved yield and reduced equipment costs by eliminating the need for precise metal masks, allowing for precise alignment and uniform thickness of light-emitting layers.
Implementation Method 1
Light-emitting devices (also referred to as EL devices or EL elements) utilizing electroluminescence (hereinafter referred to as EL)
Data Source
AI summary
A high-resolution or high-definition display apparatus is provided. The display apparatus includes a first light-emitting device and a second light-emitting device. The first light-emitting device includes a first conductive layer, a second conductive layer over the first conductive layer, a first light-emitting layer over the second conductive layer, and a common electrode over the first light-emitting layer. The second light-emitting device includes a third conductive layer, a fourth conductive layer over the third conductive layer, a second light-emitting layer over the fourth conductive layer, and the common electrode over the second light-emitting layer. The second conductive layer covers a side surface of the first conductive layer, the fourth conductive layer covers a side surface of the third conductive layer, an end portion of the first light-emitting layer is aligned or substantially aligned with an end portion of the second conductive layer, and an end portion of the second light-emitting layer is aligned or substantially aligned with an end portion of the fourth conductive layer.