Sub-Pixel Bank Layout for Uniform Solution-Coated OLED Displays
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Solution Overview
Problem
The existing electroluminescent display devices face challenges in manufacturing large-sized and high-definition displays due to the limitations of the vacuum thermal evaporation process, which increases costs and is prone to manufacturing variations and shadow effects from masks.
Innovation Solution
The electroluminescent display device employs a matrix arrangement of pixels with sub-pixels, where light-emitting layers are formed using a solution process, eliminating the need for masks and allowing for larger regions to be coated, thereby reducing manufacturing costs and enabling larger, higher-resolution displays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If vacuum thermal evaporation process with masks is used, then light-emitting layers can be formed with precise patterning, but manufacturing costs increase and manufacturing variations occur
Solution Approach 1:
The patent removes the mask component from the manufacturing process entirely. Instead of using masks to define patterns during evaporation, the invention forms light-emitting layers by sequentially depositing different materials that are later selectively removed, eliminating mask-related costs and manufacturing variations while maintaining patterning precision
Solution Approach 2:
The patent replaces the mechanical mask system with a chemical/sequential deposition approach. Rather than physically blocking deposition with masks, the invention uses controlled sequential evaporation of different materials followed by selective removal, substituting a mechanical patterning system with a more flexible process that reduces manufacturing complexity
2Manufacturing precision
If vacuum thermal evaporation process with masks is used, then light-emitting layers can be formed, but shadow effects from masks occur and manufacturing variations increase
Solution Approach 1:
The patent extracts and removes the mask from the deposition process, eliminating the source of shadow effects. By using sequential material deposition without physical masks, the invention achieves uniform light-emitting layers free from mask-related shadowing and manufacturing variations
Solution Approach 2:
The patent performs preliminary sequential deposition of multiple materials in a specific sequence before final pattern formation. This preliminary action of depositing materials that will be selectively removed later allows for uniform coverage without shadow effects, improving light-emitting layer uniformity
3Manufacturing precision
If masks are used in evaporation process, then precise patterning is achieved, but device complexity and manufacturing steps increase
Solution Approach 1:
The patent removes masks and their associated alignment and handling complexity from the manufacturing process. By using sequential deposition of evaporable materials followed by selective removal, the invention achieves precise sub-pixel patterning with simpler manufacturing steps and fewer components
Solution Approach 2:
The patent changes the deposition parameters and sequence, depositing different materials in a specific order (first evaporable material, then second evaporable material, then third evaporable material) with different evaporation rates and conditions. This parameter control enables precise patterning without masks, reducing process complexity
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 reduces manufacturing costs and allows for the production of large-sized, high-definition electroluminescent displays with improved efficiency and reduced variability, while maintaining image quality by minimizing mura and ensuring uniform light-emitting layer thickness.
Implementation Method 1
each of the first, second, third and fourth pixels including first, second and third sub-pixels; a light-emitting diode disposed at each of the first, second and third sub-pixels and including a first electrode, a light-emitting layer and a second electrode
Data Source
AI summary
An electroluminescent display device can include a plurality of pixels arranged in a matrix form along a first direction and a second direction, each pixel including first, second, and third sub-pixels, and a first bank pattern having a first height, and a second bank pattern having a second height, the first height being smaller than the second height, wherein the second bank pattern is parallel in two directions. The first bank pattern defines same color sub-pixels of different pixels, and wherein the second bank pattern defines different color sub-pixels of the same pixel. The second bank pattern includes first patterns disposed between the adjacent different color sub-pixels along a third direction crossing the first and second directions and between the adjacent different color sub-pixels along a fourth direction crossing the first, second, and third directions and second patterns disposed between the second sub-pixels adjacent to each other.