OLED Anode Plasma Treatment via Pixel-Specific Voltage Control
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Solution Overview
Problem
Conventional oxygen plasma surface treatment processes for OLED displays do not differentiate between pixels of different colors, resulting in unoptimized surface characteristics and driving performance for each color pixel.
Innovation Solution
A method is introduced where different plasma voltages are applied to test pads connected to red, green, and blue pixels during the oxygen plasma surface treatment process, allowing for tailored surface treatment of each color pixel to optimize hole injection and reduce work function, thereby enhancing driving performance and luminous efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional oxygen plasma surface treatment process is applied uniformly to the entire mother substrate, then the process is simple and fast, but the surface characteristics and hole injection amount cannot be optimized for each color pixel
Solution Approach 1:
The patent divides the plasma treatment process into separate controllable units by introducing test pads connected to different pixel regions (red, green, blue). Each test pad can receive independent plasma treatment through separate plasma generation electrodes, enabling region-specific surface characteristic optimization without treating the entire substrate uniformly.
Solution Approach 2:
The patent applies different plasma treatment conditions (different voltages, powers, or durations) to different pixel regions based on their specific requirements. For example, red pixels may receive one plasma treatment parameter set while green and blue pixels receive different parameters, optimizing hole injection and surface characteristics for each color specifically rather than using a uniform approach.
2Reliability
If different plasma voltages are applied to test pads for different color pixels, then driving performance is optimized for each pixel, but the process complexity increases
Solution Approach 1:
The patent introduces test pads as intermediary elements between the plasma generation system and the pixel electrodes. These test pads serve as mediators that can be independently connected to different pixel regions and subjected to controlled plasma treatment. This intermediary structure enables precise control over plasma application to each pixel type while maintaining a manageable process architecture.
Solution Approach 2:
The patent varies plasma treatment parameters (voltage, power, duration, gas flow) across different test pads corresponding to different color pixels. By changing these parameters locally, the process optimizes surface characteristics and work function reduction for each pixel type, improving hole injection efficiency and overall driving performance without requiring complete process redesign.
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 approach enables optimized driving performance, including improved driving voltage, luminous efficiency, and lifespan for each color pixel by controlling the surface characteristics specifically for red, green, and blue pixels, leading to better overall display performance.
Implementation Method 1
The anode may then be treated by an oxygen (O2) plasma surface treatment process. The oxygen plasma surface treatment process reduces a work function of the anode to increase an injection amount of the holes and removes a remaining layer at the anode
Implementation Method 2
Electrons from one electrode (i.e., cathode) may combine with holes from another electrode (i.e., anode) in the organic emission layer to form excitons. As a result of the combination, light may be emitted when the excitons discharge energy.
Data Source
AI summary
A manufacturing method of an organic light emitting diode (OLED) display includes manufacturing a mother substrate including a plurality of panels formed with a plurality of anodes for each pixel and a test pad connected to each anode of the panel. The method further includes loading the mother substrate into a plasma chamber and applying a plasma voltage to the test pad of the mother substrate to perform a plasma surface treatment process. The test pad is applied with a different plasma voltage for each pixel.