Organic Light Emitting Display Device Bank Layer Fabrication
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Solution Overview
Problem
The thermal evaporation process for fabricating organic light emitting display devices is complex, costly, and impractical for large-sized displays due to the need for precise metal mask alignment and deposition, leading to increased costs and limitations in scalability.
Innovation Solution
A coating process is used to form an organic light emitting layer with hydrophobic bank layers, allowing for uniform thickness and rapid formation of the layer by spreading organic light emitting material between pixels, which simplifies the fabrication process and enables larger display sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If thermal evaporation process with metal mask is used to form organic light emitting layer, then deposition precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts and removes the metal mask component from the thermal evaporation process. Instead of using a metal mask to define pixel regions, the invention forms an organic bank layer that serves as the boundary structure, eliminating the need for separate metal mask deposition, alignment, and removal steps while maintaining precise material deposition control.
Solution Approach 2:
The patent performs preliminary formation of the organic bank layer before depositing the organic light emitting layer. The organic bank layer is formed first to define the pixel boundaries and prevent material mixing, which simplifies subsequent deposition processes by eliminating the need for metal mask alignment and removal operations.
2Manufacturing precision
If thermal evaporation process with metal mask alignment is used, then manufacturing precision is improved, but loss of time increases
Solution Approach 1:
The patent removes the time-consuming metal mask alignment and removal steps from the fabrication process. By using an organic bank layer formed through coating processes instead of metal masks, the invention eliminates multiple sequential operations (mask deposition, alignment, evaporation, mask removal) and replaces them with a simpler, faster process flow.
Solution Approach 2:
The patent replaces the mechanical metal mask alignment system with a chemical/coating-based organic bank layer formation process. The organic bank layer is formed through coating and patterning processes that do not require precise mechanical alignment equipment, thereby reducing fabrication time and simplifying the manufacturing system.
3Manufacturing precision
If thermal evaporation process is used for large size displays, then manufacturing precision is maintained, but device complexity and cost increase
Solution Approach 1:
The patent replaces the thermal evaporation mechanical deposition system with a coating-based organic bank layer formation process. Coating processes are inherently more scalable to large substrates and do not require the complex vacuum chamber and mask alignment systems needed for thermal evaporation, enabling cost-effective production of large-size displays while maintaining layer formation precision.
Solution Approach 2:
The organic bank layer serves multiple functions simultaneously: it defines pixel boundaries, prevents material mixing between adjacent pixels, and provides a foundation for subsequent organic light emitting layer deposition. This multi-functionality eliminates the need for separate metal mask components and simplifies the overall manufacturing process for large-size displays.
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 coating process simplifies the formation of organic light emitting layers, ensures uniform thickness, and allows for the production of larger-sized displays, reducing complexity and cost compared to traditional thermal evaporation methods.
Implementation Method 1
the width of the third bank layer is dependent upon the hydrophobic property of the third bank layer
Implementation Method 2
The first bank layer is made of a hydrophilic material and the second and third bank layers made of a hydrophobic material
Data Source
AI summary
An organic light emitting display device and a method of fabricating thereof are discussed. The organic light emitting display device according to an example of the invention comprises a first substrate; a plurality of first bank layers arranged along a first direction and a second direction on the first substrate to define a plurality of pixels; a plurality of second bank layers disposed along the first direction on the first bank layers to divide columns of pixels having different colors; a plurality of third bank layers disposed along the second direction on the first bank layers; and an organic light emitting diode in each pixel, the organic light emitting diode including an organic light emitting layer, wherein the third bank layer is made of a same material as the second bank layer and the width of the third bank layer is smaller than that of the second bank layer.