OLED Pixel Electrode Patterning Without Metal Mask Blur
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing of high-resolution, high-definition, and large display devices with organic EL devices is hindered by issues such as non-uniform thickness of island-shaped light-emitting layers due to blurring during vapor deposition, requiring multiple manufacturing equipment lines for maintenance, and increased initial investment.
Innovation Solution
A method involving the formation of island-shaped light-emitting layers using sacrificial layers and resist masks, followed by shared counter electrodes and conductive layers to ensure uniform thickness and electrical isolation, reducing equipment requirements and maintaining high yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a vacuum evaporation method using a metal mask is used to form island-shaped light-emitting layers, then the manufacturing process can be simplified, but the thickness uniformity deteriorates due to outline blurring during vapor deposition
Solution Approach 1:
The patent applies preliminary action by forming a planarization layer before the light-emitting layer to pre-compensate for surface irregularities. This ensures that subsequent vapor deposition occurs on a uniform surface, preventing outline blurring and thickness variation in the light-emitting layer while maintaining the simplicity of the vacuum evaporation method.
Solution Approach 2:
The patent introduces a planarization layer as an intermediary between the substrate and the light-emitting layer. This intermediate layer acts as a buffer that smooths out surface variations and prevents direct transmission of substrate irregularities to the light-emitting layer, thereby maintaining thickness uniformity without complicating the manufacturing process.
2Reliability
If multiple manufacturing equipment lines are prepared for metal mask maintenance, then device fabrication reliability is improved, but initial investment and device complexity increase
Solution Approach 1:
The patent extracts the metal mask from the manufacturing process entirely by replacing it with a photoresist-based patterning method. This eliminates the need for metal mask cleaning and maintenance, allowing single equipment line operation while maintaining fabrication reliability through alternative patterning techniques using photolithography and sacrificial layers.
Solution Approach 2:
The patent replaces expensive, reusable metal masks with disposable photoresist patterns and sacrificial layers. These temporary structures are formed, used for patterning, and then removed, eliminating the need for costly metal mask maintenance infrastructure and reducing equipment complexity to a single manufacturing line.
3Measurement precision
If high-resolution display devices are manufactured with island-shaped light-emitting layers, then display quality is improved, but manufacturing yield deteriorates due to low dimensional accuracy of metal masks
Solution Approach 1:
The patent replaces the mechanical metal mask system with a photolithographic patterning system. Instead of relying on physical mask dimensional accuracy, the new method uses optical patterning with photoresist and chemical processing, which provides superior dimensional control and accuracy for high-resolution displays, thereby improving manufacturing yield.
Solution Approach 2:
The patent changes the fundamental parameter of patterning from mechanical (metal mask physical dimensions) to chemical-optical (photoresist pattern formation). This parameter change enables much finer dimensional control and higher accuracy in light-emitting layer formation, supporting high-resolution displays without sacrificing manufacturing yield.
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 method enables the production of high-resolution, high-definition, and large display devices with improved reliability and yield, while minimizing equipment needs and maintenance costs.
Implementation Method 1
processing the first layer and the first sacrificial layer to expose at least part of the second pixel electrode
Implementation Method 2
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 device is provided. The display device is manufactured by forming a first pixel electrode and a second pixel electrode; forming a first layer over the first pixel electrode and the second pixel electrode; forming a first sacrificial layer over the first layer; processing the first layer and the first sacrificial layer to expose at least part of the second pixel electrode; forming a second layer over the first pixel electrode and the second pixel electrode; forming a second sacrificial layer over the second layer; processing the second layer and the second sacrificial layer to expose at least part of the first sacrificial layer; removing the first sacrificial layer and the second sacrificial layer; forming a third layer over the first pixel electrode and the second pixel electrode; forming a counter electrode over the third layer; and processing the third layer and the counter electrode to remove at least part of each of the third layer and the counter electrode included in a region between the first pixel electrode and the second pixel electrode in a top view.