OLED Micro-Cavity Structure with Varying Optical Auxiliary Layer Thickness
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Solution Overview
Problem
The manufacturing process for organic light emitting display devices with micro-cavity structures is complex and costly due to the need for repetitive deposition, photo, and etching processes to achieve different anode electrode thicknesses for red, green, and blue pixels, increasing the number of manufacturing steps and costs.
Innovation Solution
An OLED device with a common organic light emitting layer and a semi-transmissive electrode, where the distance between the first electrode and the semi-transmissive electrode varies across subpixels, along with optical auxiliary layers of different thicknesses, allows for optimized micro-cavity distances without the need for separate photolithographic steps for each pixel color, simplifying the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If separate photolithographic steps are performed for each pixel color to achieve different anode electrode thicknesses, then micro-cavity optimization for each subpixel is achieved, but the number of manufacturing steps increases and manufacturing cost increases
Solution Approach 1:
The patent merges the formation of different thickness optical auxiliary layers for red, green, and blue subpixels into a single photolithographic step. By defining multiple pattern regions (first, second, and third pattern regions) in one photomask, the process creates varying thicknesses of the optical auxiliary layer simultaneously across different subpixel areas, eliminating the need for separate deposition and etching steps for each color.
Solution Approach 2:
The patent introduces a new dimensional approach by creating lateral variations in the optical auxiliary layer thickness through photolithographic patterning rather than through vertical deposition control. The optical auxiliary layer is formed with different thicknesses in different lateral regions (corresponding to red, green, blue subpixels) by defining pattern regions with different etch selectivities or exposure characteristics, thus achieving micro-cavity optimization without multiple sequential steps.
2Manufacturing precision
If separate photolithographic steps are performed for each pixel color, then micro-cavity distance is optimized for each subpixel, but manufacturing cost increases
Solution Approach 1:
The patent combines multiple manufacturing operations into a single integrated process step. By incorporating the formation of thickness-varied optical auxiliary layers for all subpixel colors into one photolithographic step with multiple pattern regions, it eliminates the need for repeated deposition, photo, and etching cycles, thereby reducing material waste, equipment usage, and overall manufacturing cost while maintaining precise micro-cavity control.
Solution Approach 2:
The optical auxiliary layer serves multiple functions simultaneously: it acts as an etch stop layer, defines the micro-cavity distance, and provides color-specific optical path length control. By making this single layer multi-functional through strategic patterning into multiple pattern regions, the patent eliminates the need for separate specialized layers or processes for each subpixel type, simplifying the overall manufacturing workflow and reducing costs.
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 reduces the number of manufacturing processes, lowers costs, and enhances light emission efficiency by customizing micro-cavity distances for each subpixel, improving the overall performance of the OLED device.
Implementation Method 1
the photoreactive organic film includes diarylethene molecules, and thus has a photo-isomerization property
Implementation Method 2
hole and electron are respectively moved to the organic light emitting layer via the hole transporting layer and the electron transporting layer, and are then combined to each other in the organic light emitting layer, to thereby emit light
Implementation Method 3
the light-emission efficiency is improved by amplification and constructive interference of the light through repetitive reflection and re-reflection of the light emitted from the organic light emitting layer between the anode and cathode electrodes
Data Source
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AI summary
Disclosed is an OLED device capable of reducing the number of manufacturing processes to apply a micro-cavity structure, and a method for manufacturing the same, wherein the OLED device may include a unit pixel having first to third subpixels, wherein each of the first to third subpixels includes a first electrode, an organic light emitting layer disposed on the first electrode, a second electrode disposed on the organic light emitting layer and formed of a transparent metal material, an encapsulation film for covering the second electrode, and a semi-transmissive electrode disposed on the encapsulation film, wherein a distance between the first electrode and the semi-transmissive electrode in the first subpixel, a distance between the first electrode and the semi-transmissive electrode in the second subpixel, and a distance between the first electrode and the semi-transmissive electrode in the third subpixel are different from one another.