Inkjet Pixel Definition Layer via Surface Energy Control
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Solution Overview
Problem
Current methods for manufacturing pixel definition layers in display devices, such as OLEDs, involve low utilization of organic insulating materials and complex processes like plasma etching due to the fluidity of ink during ink-jet printing, leading to inefficiencies and overflow issues.
Innovation Solution
A surface treatment method is applied to the substrate to differentiate the surface energy between pixel and non-pixel regions, allowing for the formation of pixel division walls through ink-jet printing, using techniques like self-assembled monomolecular layers and ultraviolet irradiation to prevent ink overflow, and subsequent curing treatments to secure the pixel definition layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If spin coating or blade coating method is used to prepare organic insulating film, then the organic insulating film can be formed, but the utilization ratio of organic insulating material is low
Solution Approach 1:
The patent replaces the mechanical spin coating or blade coating system with an inkjet printing system that deposits organic insulating material directly in a patterned manner, eliminating the need for full-substrate coating and subsequent patterning steps, thereby significantly improving material utilization ratio
Solution Approach 2:
The patent applies surface treatment to the substrate before inkjet printing to create regions with different surface energies, which preliminarily defines where the organic insulating material will adhere during inkjet printing, enabling direct pattern formation without waste
2Manufacturing precision
If solvent is spray-coated to form pixel division walls by coffee-ring effect, then pixel definition layer can be formed, but additional processes such as plasma etching are required
Solution Approach 1:
The patent extracts and eliminates the complex multi-step process (spin coating, solvent spray-coating, plasma etching) by using inkjet printing with surface-treated substrates to directly form the pixel definition layer in a single integrated step
Solution Approach 2:
The patent changes the surface energy parameters of different substrate regions through surface treatment, creating hydrophilic pixel regions and hydrophobic non-pixel regions that naturally guide inkjet-deposited material to form pixel division walls without additional processing
3Shape
If organic insulating material migrates due to solvent, then pixel division wall can be formed, but ink may overflow into adjacent pixel region
Solution Approach 1:
The patent applies local quality by treating different regions of the substrate with different surface properties - pixel regions are made hydrophilic while non-pixel regions are made hydrophobic, ensuring inkjet-deposited material adheres only to intended locations and preventing overflow
Solution Approach 2:
The patent replaces the solvent-driven coffee-ring effect with a controlled inkjet deposition mechanism guided by surface energy differences, providing precise material placement without uncontrolled migration or overflow
4Reliability
If multiple processes are used to form pixel definition layer, then complete pixel division wall can be formed, but production line efficiency is low
Solution Approach 1:
The patent merges multiple separate processes (substrate preparation, pattern formation, material deposition) into a single integrated inkjet printing process with preliminary surface treatment, forming the complete pixel definition layer in one step and dramatically improving production line efficiency
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 enhances the efficiency of pixel definition layer formation by preventing ink overflow and reducing the complexity of the manufacturing process, improving the utilization of organic insulating materials and increasing production line efficiency.
Implementation Method 1
performing a surface treatment on a substrate so that a surface energy of a pixel region is different from that of a non-pixel region
Implementation Method 2
performing a self-assembled monomolecular layer surface treatment on the substrate to form a monomolecular layer on a surface of the substrate
Implementation Method 3
performing an ultraviolet irradiation treatment on the non-pixel region of the substrate by using a mask plate so as to remove the silicon fluoride monomolecular layer in the non-pixel region
Implementation Method 4
forming a pixel definition layer on the substrate by ink-jet printing, wherein the pixel definition layer comprises a pixel division wall
Data Source
AI summary
A pixel circuit, driving method thereof, organic light-emitting display panel and display apparatus, comprise driving transistor, first storage capacitor, collecting unit, writing unit and light-emitting unit; the collecting unit is used for collecting the threshold voltage of the driving transistor and storing the threshold voltage into the first storage capacitor, under the control of the first scan signal; the writing unit is used for storing the data voltage inputted from the input terminal for the data voltage under the control of the second scan signal; and the light-emitting unit is used for emitting lights, driven by the data voltage and a voltage inputted from the input terminal for the controllable low voltage, under the control of the light-emitting control signal. Thus, the organic light-emitting device is not affected by the threshold voltage shift of the driving transistor, which may enhance the image uniformity of the organic light-emitting display panel effectively.