OLED Inkjet Printing Cover Plate for Uniform Drying
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet printing of organic light-emitting ink for OLED displays results in non-uniform drying profiles across the substrate due to differences in drying time between regions, affecting the thickness and quality of the organic light-emitting layer.
Innovation Solution
An apparatus and method that includes a stage, a print head, and a cover plate to move above the substrate, where the print head ejects organic light-emitting ink and the cover plate sequentially covers the inked pixels, reducing solvent volatilization and achieving uniform drying profiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If inkjet printing is used to form organic light-emitting layer, then the organic light-emitting layer can be formed by solution coating method, but the drying time difference between different regions causes non-uniform thickness
Solution Approach 1:
The patent applies preliminary action by pre-heating the substrate to a specific temperature range (60-150°C) before inkjet printing. This pre-heating prepares the substrate in advance to control solvent evaporation rate, ensuring that the organic light-emitting layer dries uniformly across all regions during the printing process, thereby preventing thickness non-uniformity while maintaining the ease of solution coating method
Solution Approach 2:
The patent changes the temperature parameter of the substrate to resolve the drying uniformity issue. By controlling the substrate temperature within 60-150°C, the solvent evaporation rate is optimized, allowing the ink to dry uniformly across different regions of the substrate. This parameter change enables the solution coating method to produce uniform thickness without requiring complex drying control mechanisms
2Loss of time
If the solvent is highly volatile, then the organic light-emitting ink dries quickly, but the drying profile becomes non-uniform across different regions
Solution Approach 1:
The patent changes the temperature parameter of the substrate to control the evaporation kinetics of highly volatile solvents. By maintaining the substrate temperature between 60-150°C, the evaporation rate is controlled to be uniform across the substrate surface, preventing the drying profile non-uniformity that would otherwise occur with highly volatile solvents. This enables quick drying while maintaining uniformity
Solution Approach 2:
The patent implements feedback control by using a temperature sensing unit to continuously monitor the substrate temperature and a temperature controlling unit to adjust the heating. This feedback mechanism ensures that the substrate temperature remains within the optimal range (60-150°C) throughout the printing and drying process, maintaining uniform drying profile even with highly volatile solvents
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 solution ensures a uniform drying profile for the organic light-emitting ink across all regions of the substrate, enhancing the display quality of OLED displays by minimizing thickness variations.
Implementation Method 1
the solvent contained in the organic light-emitting ink evaporates
Implementation Method 2
the cover plate sequentially covers the inked pixels, reducing solvent volatilization
Data Source
AI summary
Provided are an apparatus for manufacturing an OLED display and a method of manufacturing OLED display. According to another aspect of the present invention, there is provided the method of manufacturing an OLED display which includes placing a substrate having rows and columns of pixels through on a stage, ejecting organic light-emitting ink to the pixels through on the substrate by using a print head placed above the stage, and sequentially covering pixels through coated with the organic light-emitting ink with a cover plate placed above the stage.