Mn4+ Phosphor Ink Composition for Stable Micro-LED Printing
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Solution Overview
Problem
Existing methods for applying phosphor materials on miniaturized LEDs face challenges such as sedimentation, phase separation, and agglomeration due to the use of common organic solvents, which affect the stability and efficiency of quantum dot materials, limiting their practical applications in mini-LED and micro-LED technologies.
Innovation Solution
Development of an ink composition containing Mn4+ doped phosphors with specific particle sizes and viscosities tailored for various printing methods, including inkjet, flexographic, and screen printing, to stabilize the phosphor materials and enhance their application on miniaturized LEDs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If phosphor materials are mixed with common organic solvents for ink composition, then the ink can be processed and applied, but sedimentation and phase separation occur which are undesirable for subsequent coating and printing processes
Solution Approach 1:
The patent introduces a specialized solvent system as an intermediary medium that is chemically compatible with both the phosphor materials and the binder polymers. This intermediary solvent prevents direct harmful interactions between phosphor and common organic solvents, eliminating sedimentation and phase separation while enabling proper ink formulation and processing.
Solution Approach 2:
The patent modifies the chemical and physical parameters of the solvent system to create a stable dispersion medium. By changing solvent polarity, viscosity, and chemical composition parameters, the formulation achieves stable phosphor suspensions that resist sedimentation and phase separation while remaining processable for coating and printing applications.
2Length of moving object
If phosphor materials with small particle sizes are used for mini-LED and micro-LED applications, then the phosphors can be applied to miniaturized LEDs, but they tend to agglomerate when mixed with commonly used solvents making it unsuitable for ink compositions
Solution Approach 1:
The specialized solvent system acts as a protective intermediary that prevents agglomeration of small phosphor particles. The solvent's specific chemical properties provide steric or electrostatic stabilization that keeps sub-10 micron particles dispersed throughout the ink composition, preventing the formation of aggregates that would compromise ink suitability.
Solution Approach 2:
The patent creates a composite ink formulation combining phosphor particles with specifically selected binders and solvent systems. This composite approach ensures that the small phosphor particles are stabilized within the matrix through synergistic interactions between components, maintaining dispersion stability while enabling application to miniaturized LED devices.
3Quantity of substance
If quantum dot materials are used for ink jet printable ink, then nanometer particle sizes with strong absorption coefficient are achieved, but low quantum efficiency and poor thermal stability significantly limit practical applications
Solution Approach 1:
The patent adopts phosphor materials as a more durable and reliable alternative to quantum dots. While quantum dots offer high absorption coefficients, the phosphor-based ink formulation provides superior thermal stability and quantum efficiency, making it suitable for practical applications in mini-LED and micro-LED lighting and display technologies.
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 ink composition provides stable dispersions of phosphors with improved thermal stability and quantum efficiency, enabling high-quality color rendering and efficient deposition on mini-LEDs and micro-LEDs, overcoming the limitations of quantum dots.
Implementation Method 1
Mn4+ doped phosphors of formula (1) are red emitting phosphors that have been used in lighting and display applications
Implementation Method 2
Quantum dot material has nanometer particle sizes with a strong absorption coefficient
Data Source
AI summary
Phosphor ink compositions and systems and methods for depositing such phosphor containing ink are disclosed. An ink composition of in accordance with the present disclosure comprises a phosphor material comprising a Mn4+ doped phosphor of Formula 1 Ax[MFy]:Mn4+ (I) and at least one binder material or solvent, wherein the Mn4+ doped phosphor has a D50 particle size from about 0.5 microns to about 15 microns, and wherein the ink composition has a viscosity from more than 2,000 cP to about 30,000 cP, where A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is the absolute value of the charge of the [MFy] ion; and y is 5, 6 or 7.