Functional Material Granulation for Low-Dust OLED Processing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing powders and pellets used in manufacturing electronic devices, such as organic light-emitting diodes (OLEDs), suffer from dust generation, electrostatic charging, low bulk density, complexity in production, and high cost, which affect processability, transportability, and storability, while also requiring stringent safety measures.
Innovation Solution
A method to produce granules from a functional material melt by transferring it under controlled pressure and cooling, resulting in granules with a low fine fraction and improved properties for use in electronic devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If powders are used as functional material, then the material can be easily processed, but dust is generated and electrostatic charging occurs leading to residue and safety issues
Solution Approach 1:
The patent changes the physical form parameter of the functional material from powder to granules with controlled size distribution (0.1-1.0 mm). This parameter change eliminates dust generation while maintaining processability, as the granular form does not generate harmful dust or electrostatic charging during handling.
Solution Approach 2:
The patent applies local quality by creating granules with a specific size distribution where the majority of particles fall within the 0.1-1.0 mm range. This localized control of particle size ensures that the material has optimal properties for both handling and device performance, eliminating the harmful effects of fine powder while maintaining manufacturability.
2Object-generated harmful factors
If pellets are used as functional material, then dust generation is reduced, but production becomes complex and expensive
Solution Approach 1:
The patent segments the functional material into granules of controlled size (0.1-1.0 mm) rather than using fully densified pellets. This segmentation approach reduces dust generation compared to powder while avoiding the complex multi-step production process required for traditional pellets, achieving a balance between harmful factor reduction and manufacturing simplicity.
3Ease of manufacture
If fine fraction is increased in granules, then processability improves, but device performance and lifetime are adversely affected
Solution Approach 1:
The patent optimizes the particle size distribution parameter by limiting the fine fraction (particles <0.1 mm) to less than 10 wt.%. This parameter optimization ensures sufficient processability while preventing the adverse effects on device performance and lifetime that would result from excessive fine particles.
Solution Approach 2:
The patent applies local quality control by specifying that at least 90 wt.% of granules should have a diameter of 0.1-1.0 mm. This localized quality control ensures that the majority of the material has optimal properties for both processing and device performance, while allowing a small controlled amount of finer particles for manufacturability.
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 granules enhance processability, transportability, and storability, with improved device performance, particularly in OLEDs, by reducing dust and electrostatic issues, and maintaining consistent quality and efficiency.
Implementation Method 1
the melt transferred into the drop tube according to step B) is cooled with an inert gas in step C)
Implementation Method 2
the pressure at which the melt is transferred into a drop tube according to step B) is higher than the pressure in the drop tube
Data Source
Figure 1~2
AI summary
The present invention describes a method for producing granular material, containing at least one functional material (FM), which can be used to produce functional layers of electronic devices. The invention also relates to a granular material obtainable according to the present method, and to the use of said granular material for the production of an electronic device.