OLED Fabrication Using Heat Transfer to Pattern Organic Layers
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Solution Overview
Problem
Full color OLEDs face issues with differing optical thicknesses of R, G, and B pixels, leading to deteriorated color coordinates and efficiency characteristics.
Innovation Solution
A method using a heat transfer method to pattern organic layers, where R and G emission layers are patterned to specific thicknesses by subtracting the thickness of the B emission layer, and charge transport layers are formed with optimized thicknesses to improve device characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional fabrication methods are used to form organic layers in full color OLEDs, then the device structure can be maintained, but the optical thicknesses of R, G and B pixels differ causing deteriorated color coordinates and efficiency characteristics
Solution Approach 1:
The patent segments the organic layer formation process into distinct stages: first forming a common hole injection layer and hole transport layer across the entire substrate, then separately patterning the emission layers for R and G pixels using a heat transfer method. This segmentation allows precise thickness control for each pixel type while maintaining manufacturing feasibility.
Solution Approach 2:
The patent applies local quality by creating different thickness profiles for different pixel regions. The R and G emission layers are patterned to specific thicknesses (300-400 Å) while the B emission layer has a different thickness (100-200 Å), optimizing the optical characteristics for each color while maintaining overall device performance.
2Reliability
If the organic layers are patterned to optimize thickness for each pixel color, then color coordinates and efficiency improve, but the fabrication process becomes more complex
Solution Approach 1:
The patent merges multiple functions into the heat transfer method process. A single heat transfer step simultaneously patterns both the hole transport layer and emission layers for R and G pixels, reducing the total number of fabrication steps while achieving the required thickness precision for optimized device characteristics.
Solution Approach 2:
The patent performs preliminary action by first forming the common hole injection layer and hole transport layer across the entire substrate before patterning the emission layers. This preliminary formation of uniform base layers simplifies subsequent patterning steps and ensures consistent electrical characteristics across all pixels.
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 simplifies the fabrication process, improves device characteristics, and enhances color coordinates and efficiency, making it suitable for high-resolution OLEDs.
Implementation Method 1
patterning the R and G emission layers by a heat transfer method using a heat transfer device having a transfer layer
Data Source
AI summary
The present invention relates to a flat panel display, and more particularly, to a method of fabricating an organic light emitting display device so as to improve device characteristics by patterning a plurality of organic layers using a heat transfer method to optimize thicknesses according to R, G and B pixels. The method includes: forming lower electrodes of R, G and B pixels on an insulating substrate; forming an organic layer on the insulating substrate; and forming an upper electrode on the organic layer. Formation of the organic layer includes forming a hole injection layer and a hole transport layer of the R, G and B pixels on the entire surface of the substrate as a common layer. The R and G emission layers are patterned by a heat transfer method using a heat transfer device having a transfer layer such that an organic layer is patterned to a thickness obtained by subtracting a thickness of the B emission layer from the thicknesses of the R and G emission layers required in R and G colors.