Organic Light Emitting Display Patterning via Detachment Film
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Solution Overview
Problem
Existing methods for manufacturing organic light emitting display devices face challenges in achieving high definition and large size due to technical limitations, such as mask drooping in fine metal mask methods, material spread issues, exposure of organic light emitting elements in ink-jet methods, and disconnection faults and etch-depth control problems in etch processes, which deteriorate the performance and luminous properties of the devices.
Innovation Solution
A manufacturing method involving the formation of thin film transistors, passivation layers, and bank patterns on a substrate, followed by the use of a detachment film with polymer clay and elastomer materials to efficiently remove photoresist and organic material patterns without residual films, ensuring precise patterning and enhanced adhesion for improved luminous properties and process efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the fine metal mask method is used for patterning, then the organic light emission layer can be formed, but the mask droops due to its weight and forces a desired pattern to be not formed, making it difficult to realize high definition
Solution Approach 1:
The patent removes the metal mask entirely from the patterning process. Instead of using a metal mask with openings, the invention uses a photoresist pattern formed through photolithography to define the organic light emission layer regions, eliminating mask drooping issues completely
Solution Approach 2:
Instead of forming the organic light emission layer through openings in a metal mask, the patent inverts the approach by forming a photoresist pattern and then depositing the organic material only in the exposed regions, using the photoresist as the defining structure rather than a mask with holes
2Ease of manufacture
If the ink-jet method is used to jet liquid material, then the organic light emitting elements can be formed, but the elements must be exposed while the process is being performed, causing performance deterioration
Solution Approach 1:
The patent performs the patterning action in advance by forming the photoresist pattern before depositing the organic light emission layer. This preliminary patterning step defines all subsequent deposition regions, eliminating the need for continuous exposure during material jetting or deposition
Solution Approach 2:
The patent segments the manufacturing process into distinct steps: first forming the photoresist pattern, then depositing the organic material in defined regions, and finally removing the photoresist. This segmentation allows the organic elements to remain covered and protected during material deposition
3Productivity
If existing etch processes are used to remove photoresist, then the photoresist pattern can be removed, but metal can be in direct contact with etchant causing disconnection faults and making etch-depth control difficult
Solution Approach 1:
The patent introduces an intermediary layer (the organic light emission layer) between the metal electrode and the etchant. When photoresist is removed using solvent, the etchant cannot directly contact the metal because the organic layer provides protection, preventing disconnection faults while allowing efficient photoresist removal
Solution Approach 2:
The organic light emission layer is deposited beforehand to serve as a protective cushion between the metal electrode and subsequent etching processes. This preliminary protective layer prevents direct metal-etchant contact that would cause disconnection faults
4Device complexity
If the lift-off method is used to form fine patterns, then only exposure and development processes are needed without etch processes, but residual film is caused by strong adhesion force of photoresist and organic light emission layer EML must be exposed to solvent, causing faults and deteriorating luminous properties
Solution Approach 1:
The patent uses a disposable photoresist pattern that is intentionally designed to be removed after serving its patterning function. The photoresist is applied, defines the pattern during organic layer deposition, and then is completely removed with solvent, leaving no harmful residual film that would affect luminous properties
Solution Approach 2:
The patent changes the chemical parameters of the removal process by using specific solvents that selectively dissolve the photoresist without affecting the organic light emission layer. This parameter change allows complete photoresist removal without exposing the organic layer to harsh conditions that would cause faults
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-definition, large-sized organic light emitting display devices with improved luminous properties and extended lifespan by preventing residual film formation and foreign substance generation, thus enhancing productivity and quality.
Implementation Method 1
The detachment film includes polymer clay and is disposed on the organic material pattern and formed to encompass side surfaces of the organic material pattern and the photoresist pattern
Implementation Method 2
removing the photoresist pattern and the organic material pattern using a detachment film. The detachment film includes polymer clay
Data Source
AI summary
A manufacturing method of an organic light emitting display device is disclosed which includes: forming a thin film transistor on each sub-pixel region which is defined in a substrate; forming a passivation layer on the substrate provided with the thin film transistor; forming a first electrode of an organic light emitting diode in each sub-pixel region of the passivation layer; forming a bank pattern in boundaries of the sub-pixel region of the passivation layer; forming a photoresist pattern, which exposes a first sub-pixel region, on the bank pattern; forming an organic light emission layer on the first electrode within the first sub-pixel region and an organic material layer on the photoresist pattern by depositing an organic material on the entire surface of the substrate provided with the photoresist pattern; and removing the photoresist pattern and the organic material pattern using a detachment film.