Array Substrate Well Structure for Uniform OLED Inkjet Films
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Solution Overview
Problem
Inkjet printing technologies for manufacturing OLED films face issues with uneven film formation due to ink drops climbing along the edges of pixel defining layers, leading to non-uniform photochromic and light-emitting effects and reduced working life of display components.
Innovation Solution
A method for manufacturing an array substrate involving the formation of a pixel defining layer with hydrophilic side surfaces and a hydrophobic material layer that covers the side walls, creating an overlapped region with a hydrophobic outer surface and an exposed region with a hydrophilic outer surface, which improves the uniformity of organic functional layers during inkjet printing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If inkjet printing is used to form OLED films, then production capacity and material utilization rate are improved, but ink drops climb along pixel defining layer edges causing non-uniform film formation
Solution Approach 1:
The pixel defining layer is designed with different surface properties at different locations: the top surface is hydrophobic while the side surfaces are hydrophilic. This local differentiation prevents ink drops from climbing along the edges by creating a surface energy gradient that directs ink spreading only in the horizontal direction within the pixel region, thereby maintaining film uniformity while preserving the high productivity of inkjet printing
2Reliability
If hydrophobic materials are used to repel ink drops, then ink climbing is prevented, but attractive forces are needed for proper material adhesion
Solution Approach 1:
The pixel defining layer uses local quality differentiation where hydrophobic regions provide repulsive forces to prevent ink climbing, while hydrophilic regions provide attractive forces for proper material adhesion. This spatial separation of opposing forces allows simultaneous achievement of ink climbing prevention and adequate adhesion strength
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 enhances the uniformity of the organic functional layers, improving the photochromic and light-emitting effects and extending the working life of the display components by balancing attractive and repulsive forces between hydrophilic and hydrophobic materials.
Implementation Method 1
a side wall of each of the plurality of accommodating wells comprises a hydrophilic side surface
Implementation Method 2
improves the uniformity of organic functional layers during inkjet printing
Implementation Method 3
a hydrophobic material layer that covers the side walls, creating an overlapped region with a hydrophobic outer surface
Data Source
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AI summary
A method for manufacturing an array substrate includes: forming a pixel defining layer having a plurality of accommodating wells over a substrate, and forming a hydrophobic material layer over the pixel defining layer. A side wall of each accommodating well comprises a hydrophilic side surface. The hydrophilic side surface is partially covered by the hydrophobic material layer to thereby form an overlapped region having a hydrophobic outer surface and an exposed region having a hydrophilic outer surface. The overlapped region is on a side of the exposed region distal to the substrate. The array substrate manufactured thereby allows an organic functional layer to be evenly fabricated in each accommodating well of the pixel defining layer via inkjet printing.