OLED Display Substrate with Localized Pixel Definition Layers
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Solution Overview
Problem
The uniformity of thin films formed by inkjet printing in OLED display devices is poor due to differences in volatilization speeds of solvents between display and non-display pixel material layers, leading to inconsistent layer formation and brightness.
Innovation Solution
A display substrate with distinct adhesive properties between display and non-display pixel definition layers, where the non-display pixel definition layer has a higher adhesive property and specific surface area, and the display pixel definition layer is hydrophobic, to control solvent volatilization speeds and ensure uniformity, using materials like polysulfone, polyvinylpyridine, and fluorinated polyimide for pixel isolation patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the same pixel definition layer structure is used for both display and non-display regions, then the manufacturing process is simple, but the solvent volatilization speeds differ causing poor thin film uniformity
Solution Approach 1:
The patent applies local quality by creating different pixel definition layer structures in different regions: the display region uses a hydrophobic pixel definition layer that repels solvent and accelerates volatilization, while the non-display region uses a hydrophilic pixel definition layer that absorbs solvent and slows volatilization. This localized differentiation resolves the contradiction by maintaining manufacturing simplicity through a single process while achieving uniform thin film formation through region-specific material properties.
Solution Approach 2:
The patent changes the material parameters of the pixel definition layer between regions - specifically the hydrophobicity/hydrophilicity parameter. By selecting materials with different surface energy characteristics (hydrophobic for display region, hydrophilic for non-display region), the patent controls solvent interaction and volatilization speed, thereby achieving uniform thin film formation across different regions while maintaining a streamlined manufacturing process.
2Strength
If the non-display pixel definition layer has higher adhesive property to increase bonding force, then the bonding strength improves, but the solvent volatilization control becomes more complex
Solution Approach 1:
The patent changes the material parameter of the non-display pixel definition layer from hydrophobic to hydrophilic, which simultaneously achieves two objectives: increases adhesive property for stronger bonding force and controls solvent volatilization speed. This parameter change resolves the contradiction by using material property selection to achieve both strong bonding and volatilization control without adding structural complexity.
Solution Approach 2:
The patent employs porous materials in the non-display pixel definition layer, which provide high specific surface area for enhanced adhesive interaction with the pixel material layer. The porous structure increases bonding force through greater contact area while the hydrophilic nature of the porous material also facilitates controlled solvent absorption and volatilization, thereby achieving both strong bonding and volatilization control.
3Manufacturing precision
If the display pixel definition layer is made hydrophobic to accelerate solvent volatilization, then the thin film formation improves, but the adhesive property to pixel material layer decreases
Solution Approach 1:
The patent applies local quality by making the display pixel definition layer hydrophobic specifically in the display region where rapid solvent volatilization is needed for uniform thin film formation. This localized hydrophobicity accelerates solvent removal without affecting other regions, resolving the contradiction between achieving good thin film formation and maintaining adhesive property by confining the hydrophobic characteristic to only where it is needed.
Solution Approach 2:
The patent uses porous materials in the display pixel definition layer that provide hydrophobic surfaces for accelerated solvent volatilization. The porous structure offers high specific surface area that enhances the hydrophobic effect and volatilization rate, while the pore structure itself can provide mechanical interlocking with the pixel material layer, thereby maintaining adequate adhesive property even with hydrophobic material selection.
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 the difference in solvent volatilization speeds between display and non-display layers, enhancing the uniformity of thin films and display brightness while meeting the requirement for a narrow bezel, thereby improving the manufacturing efficiency of OLED display panels.
Implementation Method 1
the non-display pixel definition layer includes a porous structure, a surface of the porous structure includes a plurality of absorption pores
Implementation Method 2
each of the plurality of absorption pores has a diameter between 1 nm to 50 nm
Implementation Method 3
the display pixel definition layer includes a hydrophobic structure, and a surface of the hydrophobic structure includes a hydrophobic material layer
Data Source
AI summary
A display substrate, a manufacture method of a display substrate, and a display panel is provided. The display substrate includes a display region, and a non-display region extending from at least one edge of the display region, wherein the display region includes a display pixel definition layer, the non-display region includes a non-display pixel definition layer, and an adhesive property of the display pixel definition layer to a first pixel material layer in the display pixel definition layer is higher than that of the non-display pixel definition layer to a second pixel material layer in the non-display pixel definition layer.