Organic Light Emitting Display Bank Structure for Uniform Emission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The formation of organic light emitting display devices using a solution process often results in non-uniform thickness of the emission layer due to thickness deviations, leading to deteriorated display quality, reduced lifespan of elements, and the generation of dark spots.
Innovation Solution
The use of a substrate with sub-pixels arranged in intersecting directions, featuring a first bank with hydrophilic openings and a second bank with hydrophobic openings, including third openings between neighboring second openings, to control the deposition and uniformity of organic light-emitting materials, ensuring uniform thickness and preventing material mixing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If a solution process is used to form the emission layer for large-area patterning, then material use rate and thermal stability are improved, but thickness uniformity deteriorates
Solution Approach 1:
The bank structure is divided into multiple opening regions (first, second, and third openings) with different functions. The first openings are for depositing organic light-emitting materials, the second openings are for preventing material mixing, and the third openings are for controlling thickness uniformity. This segmentation allows each region to optimize its function independently.
Solution Approach 2:
Different regions of the bank are designed with different opening characteristics tailored to local requirements. The first openings have specific dimensions for material deposition efficiency, the second openings are positioned to prevent mixing at boundaries, and the third openings are strategically placed to address thickness deviation in specific areas. This local optimization resolves the thickness uniformity issue while maintaining high material use rate.
2Manufacturing precision
If a large-area fine metal mask is used for sub-pixel patterning, then deposition precision is improved, but mask bending and material deposition at unintended locations occur
Solution Approach 1:
The patent extracts and eliminates the mask component from the deposition system, replacing it with a bank structure that defines deposition regions through openings. This removes the source of mask bending and unintended material deposition while maintaining precise patterning capability through the engineered opening configuration.
3Ease of manufacture
If the emission layer thickness is not uniform, then display quality deteriorates, but the solution process is simpler than evaporation
Solution Approach 1:
The bank structure incorporates third openings specifically designed to address thickness uniformity issues in the emission layer. These additional openings are strategically positioned to control material distribution in areas prone to thickness deviation, maintaining the simplicity of the solution process while achieving uniform thickness.
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 configuration ensures uniform thickness of the organic emission layers, improves display quality, prevents lifespan reduction, and eliminates dark spots by selectively forming the emission layer in predetermined areas, enhancing the material use rate and thermal stability.
Implementation Method 1
a first bank with hydrophilic openings and a second bank with hydrophobic openings, including third openings between neighboring second openings, to control the deposition and uniformity of organic light-emitting materials
Data Source
AI summary
An organic light emitting display device comprises a substrate having a plurality of sub-pixels arranged in a first direction and a second direction intersecting the first direction; a plurality of first electrodes disposed to correspond to the plurality of sub-pixels; a first bank having a plurality of first openings exposing a portion of the plurality of first electrodes; and a second bank disposed on the first bank, having a plurality of second openings that exposes the plurality of first electrodes, and at least one third opening disposed between two neighboring second openings along the second direction.