Organic Light Emission Layer Formation Without Shadow Masks
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Solution Overview
Problem
Existing organic electroluminescent display devices face challenges in forming uniform organic light emission layers due to the use of shadow masks, which can lead to non-uniform material deposition and accuracy issues, especially for large-sized displays, and result in decreased productivity and definition.
Innovation Solution
The solution involves distributing organic light emission layers across two substrates without using shadow masks, utilizing ink-jet or nozzle-jet printing methods to form layers on red and green sub-pixel regions, and employing color filter layers to output red, green, and blue lights, allowing for large-size and high-definition displays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If shadow masks are used to form organic light emission layers, then patterned layers can be formed, but non-uniform material deposition and accuracy issues occur especially for large-sized displays
Solution Approach 1:
The patent removes the shadow mask component entirely from the fabrication process. Instead of using shadow masks to define patterns, the invention employs direct ink-jet or nozzle-jet printing methods to deposit organic light emission materials precisely at desired locations on the substrate, eliminating the masking step that causes non-uniform deposition and accuracy issues in large displays
Solution Approach 2:
The patent replaces the mechanical shadow mask system with a digital printing system. The ink-jet or nozzle-jet printing technology uses computer-controlled material ejection to form patterns directly, substituting the mechanical alignment and physical masking approach with a more precise, flexible, and scalable digital fabrication method
2Manufacturing precision
If shadow masks are used to form organic light emission layers, then patterns can be defined, but productivity decreases due to material generation issues
Solution Approach 1:
The patent eliminates the shadow mask and associated material generation process. By using ink-jet or nozzle-jet printing, materials are deposited only where needed on the substrate, eliminating the waste and rework associated with shadow mask fabrication, alignment, and the generation of excess material that must be removed or managed
Solution Approach 2:
The patent performs pattern definition and material placement in a single integrated step through direct printing. The printing system is pre-programmed with the desired pattern information, allowing precise material deposition to occur before any subsequent processing steps, eliminating the need for separate mask alignment and material generation operations that reduce productivity
3Manufacturing precision
If shadow masks are used to form organic light emission layers, then layer patterns can be created, but definition and quality deteriorate
Solution Approach 1:
The patent replaces the shadow mask mechanical system with digital ink-jet or nozzle-jet printing technology. This substitution enables superior pattern definition through computer-controlled material ejection, achieving higher resolution and sharper edges compared to the physical limitations of shadow mask alignment and material flow control
Solution Approach 2:
The patent changes the deposition parameters by using direct material ejection from printing nozzles rather than vapor deposition through mask openings. This allows precise control over material placement, droplet size, and deposition timing, resulting in improved layer definition and display quality without the diffraction and alignment issues inherent in shadow mask systems
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 formation of uniform organic light emission layers on multiple substrates, enhancing display size and definition while preventing productivity deterioration from material generation issues, and allowing for accurate color output without the limitations of shadow masks.
Implementation Method 1
utilizing ink-jet or nozzle-jet printing methods to form layers on red and green sub-pixel regions
Implementation Method 2
The deposition source is heated within a vacuum chamber and enables the organic light emission material to be vaporized and discharged through the outlet
Implementation Method 3
the vaporized organic light emission material can be discharged from the deposition source and deposited on the substrate
Implementation Method 4
employing color filter layers to output red, green, and blue lights
Data Source
AI summary
An organic electroluminescent display device is disclosed which includes: a lower substrate including a first substrate defined into red, green and blue sub-pixel regions, first and second switching elements formed in the red and green sub-pixel regions, first and second anodes each connected to the first and second switching elements, and a first organic light emission layer entirely formed on the first substrate provided with the first and second anodes; and an upper substrate including a second substrate, red and green color filter layers formed on the second substrate corresponding to the red and green sub-pixel regions, a third switching element formed on the second substrate corresponding to the blue sub-pixel region, a third anode connected to the third switching element, and a second organic light emission layer entirely formed on the second substrate provided with the red and green color filter layers and the third anode.