Organic EL Partition Wall Angle for Uniform Ink Coating
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Solution Overview
Problem
The existing methods for forming functional layers in organic electroluminescence (EL) elements using low molecular weight materials often result in film defects due to high fluidity and molecular aggregation, leading to non-uniform light emission.
Innovation Solution
The method involves forming a partition wall with a side surface angle of 40 to 60 degrees and coating ink to satisfy specific contact angle conditions, ensuring favorable pinning and uniform film thickness, even with low molecular weight materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If low molecular weight materials are used as functional layer forming material, then productivity and cost are improved, but film forming defects occur due to high fluidity and molecular aggregation
Solution Approach 1:
The patent changes the geometric parameters of the partition wall (inclination angle of 40-60 degrees) to control the fluid behavior of low molecular weight materials during coating, enabling uniform film formation while maintaining productivity benefits
2Manufacturing precision
If the partition wall side surface angle is increased to improve pinning effect, then film thickness uniformity is improved, but ink supply into concave section becomes difficult
Solution Approach 1:
The patent optimizes the partition wall inclination angle to a specific range (40-60 degrees) that balances two competing requirements: providing sufficient pinning effect for uniform film thickness while maintaining adequate ink supply to the concave section during coating
3Ease of manufacture
If ink is coated with high fluidity to improve coating coverage, then manufacturing cost is reduced, but film forming defects are generated due to molecular aggregation
Solution Approach 1:
The patent changes the physical parameters of the partition wall structure (inclination angle) to compensate for the high fluidity of the ink, enabling the use of low viscosity materials for simple coating processes while preventing film forming defects through controlled pinning
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 functional layers with high film thickness uniformity, improving light emission uniformity and efficiency, and extending the lifespan of organic EL elements.
Implementation Method 1
in a case where a contact angle of the ink with respect to the side surface of the partition wall is set to θbc and the contact angle with respect to a surface of the coating region where the ink is coated is set to θlc
Implementation Method 2
the ink is coated so as to satisfy the following expressions (1) to (3), in a case where a contact angle of the ink with respect to the side surface of the partition wall is set to θbc and the contact angle with respect to a surface of the coating region where the ink is coated is set to θlc
Implementation Method 3
forming a functional layer in the coating region by drying the ink which is coated
Data Source
AI summary
An organic EL element manufacturing method includes coating ink which contains a functional layer forming material in a coating region which is configured by a pixel electrode and a partition wall which surrounds a periphery of the pixel electrode, where, in the coating ink, the ink is coated so as to satisfy the following expressions (1) to (3) in a case where a contact angle of the ink with respect to the side surface of the partition wall is set to θbc and a contact angle with respect to a surface of the coating region where the ink is coated is set to θlc.θbc≦θlc (1)θbc≦5° (2)θlc≦20° (3)