Light-Emitting Element Ink for Uniform Display Pixel Alignment
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Solution Overview
Problem
Existing display technologies face challenges in achieving uniform dispersibility and alignment of light-emitting elements, leading to poor luminance in sub-pixels due to elements sticking together during the printing process.
Innovation Solution
An ink formulation with specific solvent properties, including Hansen solubility parameters and functional groups, is used to disperse light-emitting elements, ensuring they do not stick together and align uniformly on electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional solvents are used to disperse light-emitting elements, then the printing process can be performed, but the light-emitting elements stick together leading to poor alignment and non-uniform luminance
Solution Approach 1:
The patent applies parameter changes by carefully selecting solvents with specific Hansen solubility parameters (δD, δP, δH) within defined ranges. This changes the physical-chemical parameters of the dispersion medium to optimize both the dispersibility of light-emitting elements during printing and their stability after deposition, preventing aggregation while ensuring uniform luminance.
Solution Approach 2:
The patent uses composite material approach by formulating ink compositions containing multiple components including dispersants, solvents with specific properties, and light-emitting elements. This composite formulation achieves synergistic effects where the dispersant and solvent work together to maintain element separation during printing while ensuring proper adhesion and uniformity after deposition.
2Ease of manufacture
If light-emitting elements are dispersed in the ink, then they can be printed onto sub-pixels, but they aggregate during the printing process causing poor alignment
Solution Approach 1:
The patent controls the viscosity parameter of the ink within a specific range (20-200 cP at room temperature) to balance printability and alignment precision. This parameter optimization ensures the ink flows properly during printing while preventing light-emitting elements from aggregating, thereby achieving both ease of manufacture and high alignment precision.
Solution Approach 2:
The patent introduces dispersants as intermediary substances that mediate between the light-emitting elements and the solvent. These dispersants adsorb onto the surface of light-emitting elements, providing steric or electrostatic repulsion that prevents aggregation during printing while allowing uniform distribution and precise alignment.
3Manufacturing precision
If the dispersibility of light-emitting elements is improved, then uniform luminance can be achieved, but the complexity of ink formulation increases
Solution Approach 1:
The patent simplifies the formulation complexity by focusing on optimizing key parameters of commercially available solvents and dispersants rather than synthesizing novel compounds. By selecting solvents with specific Hansen solubility parameters and controlling viscosity within defined ranges, the patent achieves uniform luminance while maintaining formulation simplicity and ease of manufacturing.
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
The solvent-based ink improves the dispersibility and alignment of light-emitting elements, resulting in uniform luminance across sub-pixels and enhancing the performance of display devices.
Implementation Method 1
a solvent capable of dispersing light-emitting elements so that the dispersibility of the light-emitting elements can be improved
Implementation Method 2
generating an electric field over the target substrate to dispose the plurality of light-emitting elements on the first electrode and the second electrode
Data Source
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AI summary
An ink includes a solvent, and light-emitting elements dispersed in the solvent, each of the light-emitting elements comprising semiconductor layers and an insulating film partially surrounding outer surfaces of the semiconductor layers, wherein the solvent has Hansen solubility parameters of a polarity parameter between about 4 and about 9 and a hydrogen bonding parameter between about 6 and about 11.