OLED Device Color Filter Outgas Blocking Structure
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Solution Overview
Problem
Current organic light-emitting display (OLED) manufacturing techniques face challenges in applying RGB-independent deposition methods to large devices due to precision issues with metal masks and material properties, leading to pixel shrinkage and reduced OLED lifespan.
Innovation Solution
The proposed solution involves an organic light-emitting display device structure with a substrate, passivation layer, color filters, an overcoat layer, first and second electrodes, and an organic layer, where the color filters and overcoat layers are designed to block outgases, and a method of manufacturing that includes forming a pixel defining layer and polarizing film to enhance light emission and prevent pixel shrinkage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If RGB-independent deposition with micro metal mask is used, then manufacturing precision of light-emitting layer is improved, but device size is limited due to mask alignment precision and sagging
Solution Approach 1:
The patent extracts and removes the micro metal mask from the manufacturing process entirely, replacing it with a direct patterning method using a pixel defining layer formed by photolithography. This eliminates the mask-related limitations on device size while maintaining patterning precision through photoresist-based patterning processes.
Solution Approach 2:
The patent replaces the mechanical micro metal mask system with a photolithographic patterning system. Instead of using physical masks that sag and have alignment issues at large sizes, the invention uses light-based photolithography to define pixels, enabling large-area fabrication without mask-related constraints.
2Area of stationary object
If inkjet scheme is used for light-emitting layer formation, then large substrate application is enabled, but material properties deteriorate due to soluble material limitations
Solution Approach 1:
The patent replaces the inkjet deposition method with vacuum thermal evaporation or sputtering for organic layer deposition. This substitution allows the use of high-quality evaporable or sputterable organic materials that provide superior electrical and optical properties compared to soluble inkjet materials, while still enabling large substrate processing.
Solution Approach 2:
The patent changes the deposition parameters and material state by using vacuum-based physical vapor deposition methods instead of solution-based inkjet printing. This parameter change enables the use of materials with better charge transport and emission properties that can be deposited in vacuum without requiring solvents.
3Area of stationary object
If LITI technique is used, then large device manufacturing is enabled, but OLED lifespan decreases due to laser-induced damage
Solution Approach 1:
The patent extracts and eliminates the laser processing step from the manufacturing process. Instead of using LITI to transfer the organic layer, the invention directly deposits the organic layer onto the patterned substrate using vacuum evaporation or sputtering, avoiding laser-induced thermal damage that reduces OLED lifespan.
Solution Approach 2:
The patent replaces the laser-induced thermal transfer mechanism with direct physical vapor deposition. This substitution eliminates the high-temperature laser processing that can damage the organic layer and electrode interfaces, thereby extending OLED operational life while maintaining compatibility with large substrates.
4Reliability
If color filter and overcoat layer are added to block outgases, then pixel shrinkage is prevented and reliability is improved, but device structure complexity increases
Solution Approach 1:
The patent combines multiple functions into the overcoat layer: it serves as both a protective barrier against outgases from the color filter and as a planarization layer for subsequent electrode deposition. This multi-functionality approach adds necessary protection without proportionally increasing complexity, as the same layer performs multiple critical roles.
Solution Approach 2:
The patent merges the protective function against outgases with the structural overcoat layer that is already necessary for device fabrication. Instead of adding a separate protective layer, the overcoat layer is designed to simultaneously provide gas barrier properties and surface planarization, combining multiple functions in a single layer structure.
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 effectively blocks outgases from the color filter and overcoat layer, preventing pixel shrinkage and enhancing the reliability and lifespan of the OLED, making it suitable for larger devices with improved light emission properties.
Implementation Method 1
both the color filter and the overcoat layer individually covering the color filters, thereby effectively blocking outgases
Implementation Method 2
the OLED is a device that emits lights while electrons and holes are recombined in the organic light-emitting layer, the holes being injected from the anode and the electrons being injected from the cathode
Data Source
AI summary
An organic light-emitting display device includes a substrate; a passivation layer disposed on the substrate; at least one color filter disposed on the passivation layer; an overcoat layer covering the at least one color filter; a first electrode disposed on the passivation layer and surrounding the overcoat layer; a second electrode facing the first electrode; and an organic layer disposed between the first electrode and the second electrode.