OLED Emitting Layer Deposition in One Chamber to Prevent Misalignment
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Solution Overview
Problem
The fabrication process of organic light emitting diode (OLED) display devices is complicated due to the use of two independent chambers for forming multiple emitting material layers, leading to contamination and misalignment issues, which affect efficiency and productivity.
Innovation Solution
The formation of triple layered emitting material layers of a first, second, and third host and dopant is achieved in a single chamber using a single evaporation apparatus with specific shutters, allowing sequential deposition of hosts and dopants in separate regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two independent chambers are used to form multiple emitting material layers, then emission efficiency can be improved, but fabrication process complexity increases and productivity decreases
Solution Approach 1:
The patent merges multiple independent chambers into a single chamber that can form triple layered emitting material layers. The single chamber contains multiple evaporation sources (first, second, and third evaporation sources) that can sequentially deposit different hosts and dopants to create the same multi-layer structure that previously required two separate chambers, thereby simplifying the fabrication process while maintaining emission efficiency
Solution Approach 2:
The single chamber is segmented into multiple evaporation sources (first, second, and third evaporation sources) positioned at different locations. Each evaporation source can be independently controlled with its own shutter mechanism, allowing sequential deposition of different materials (first host, second host, and dopant) in specific regions without requiring separate chambers, thus maintaining layer precision while reducing overall system complexity
2Reliability
If two independent chambers are used to form multiple emitting material layers, then emission efficiency can be improved, but contamination and misalignment increase
Solution Approach 1:
By combining multiple chambers into a single chamber with multiple evaporation sources, the patent eliminates the transfer process between chambers that causes contamination and misalignment. All emitting material layers are formed in the same chamber environment, ensuring precise alignment and reducing contamination risks while maintaining the emission efficiency benefits of multi-layer structures
Solution Approach 2:
The first host layer is deposited preliminarily using the first evaporation source, then the second host layer is deposited using the second evaporation source without removing the substrate from the chamber. This sequential preliminary deposition action ensures precise alignment and eliminates contamination that would occur during chamber transfers, while still achieving the desired multi-layer emitting structure
3Manufacturing precision
If multiple emitting material layers are formed using separate chambers, then material deposition can be controlled, but productivity decreases
Solution Approach 1:
The patent combines multiple chamber operations into a single chamber with multiple evaporation sources that can operate sequentially. The first, second, and third evaporation sources can deposit their respective materials in sequence without requiring substrate transfer between chambers, significantly reducing fabrication time while maintaining precise material deposition control through individual source regulation
Solution Approach 2:
The fabrication process continues without interruption within the same chamber as each evaporation source deposits its material layer sequentially. The substrate remains in the chamber throughout the process, and each evaporation source can be activated in sequence to deposit different materials, eliminating the downtime associated with chamber transfers and thereby improving productivity while maintaining deposition precision
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 improves efficiency and productivity by simplifying the fabrication process, reducing contamination and misalignment, and enhancing electron mobility, thereby improving emission efficiency.
Implementation Method 1
a first emitting material layer by depositing the first host and the dopant of the first and third evaporation sources on the substrate
Data Source
AI summary
An organic light emitting diode display device includes a substrate having a plurality of subpixels; and an emitting material layer in the plurality of subpixels on the substrate, wherein the emitting material layer in at least one of the plurality of subpixels comprises: a first emitting material layer including a first host and a dopant; a second emitting material layer on the first emitting material layer and including a second host and the dopant; and a third emitting material layer on the second emitting material layer and including one of the dopant and the second host.