OLED Evaporation via Electric Field Selective Deposition
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Solution Overview
Problem
The alignment errors in the fine metal mask (FMM) during the film forming process of OLED panels lead to deformation and unfavorable production of high-resolution OLED panels due to factors like temperature, magnetic field, and tensile stress, affecting the luminous efficiency and color accuracy.
Innovation Solution
A method involving electrically charging pixel electrodes and forming an electric field in an evaporation chamber to ionize and deposit OLED materials selectively, followed by an etching process to retain the material only on the charged electrodes, thereby controlling the thickness and pattern of the deposited layers to avoid alignment errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a fine metal mask (FMM) is adopted for evaporation, then the film forming process can deposit OLED materials in different pixel units, but alignment errors occur leading to deformation and reduced manufacturing precision
Solution Approach 1:
The patent removes the FMM from the evaporation system entirely, extracting the masking function and replacing it with electric field-based selective deposition. The evaporation chamber no longer requires a physical mask, eliminating alignment errors between the mask and substrate while maintaining the ability to deposit materials in specific pixel units through electrical charging control
Solution Approach 2:
The patent replaces the mechanical FMM system with an electrical field-based control system. Instead of using a physical mask that requires precise mechanical alignment, the invention uses electric fields to selectively attract or repel evaporated OLED materials to specific pixel units, substituting mechanical alignment with electrical control for superior precision
2Manufacturing precision
If FMM is used during evaporation, then material deposition can be controlled, but the mask deforms due to temperature, magnetic field, and tensile stress affecting luminous efficiency and color accuracy
Solution Approach 1:
The patent extracts the deformable FMM from the system and replaces its function with an electric field-based control mechanism. The physical mask that suffers from thermal, magnetic, and mechanical deformation is completely removed, while material deposition control is achieved through electrical charging of pixel electrodes that attract or repel evaporated materials
Solution Approach 2:
The patent changes the control parameter from mechanical mask positioning to electrical field parameters. By controlling the charging state of pixel electrodes and the evaporation source, the system dynamically controls material deposition without relying on the physical stability of a mask, making the process immune to temperature, magnetic field, and stress-induced deformations
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 resolution and luminous efficiency of OLED panels by ensuring precise deposition and retention of OLED materials, improving the color accuracy and reducing the impact of alignment errors in the film forming process.
Implementation Method 1
ionizing the evaporation material, and depositing the ionized evaporation material on the base substrate under the action of the electric field
Implementation Method 2
electrically charging pixel electrodes of pixel units, required to be deposited with a material, on the base substrate, electrically charging electrodes disposed at an evaporation source in the evaporation chamber, and forming an electric field
Data Source
AI summary
An organic light-emitting diode (OLED) display panel, a manufacturing method thereof and a display device are provided. In the manufacturing method, pixel electrodes, required to be deposited with a material, on a base substrate are charged, and electrodes at an evaporation source are charged to form an electric field; evaporation material corresponding to the material required to be deposited are placed into the evaporation source and ionized, and the ionized evaporation material are deposited on the base substrate under the action of the electric field; deposited material in other pixel units are etched off and removed, so that the evaporation material only on the previously charged pixel electrodes on the base substrate are retained; and patterns of the required material are formed by the processes of deposition and etching in turn. The manufacturing method improves the resolution of finished products and can help to improve the resolution of the OLED.