OLED Pixel Electrode Optical Resonance and Patterning
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Solution Overview
Problem
Existing organic light-emitting display devices face challenges in manufacturing complexity and display quality, particularly in achieving efficient optical resonance and luminous efficiency.
Innovation Solution
The organic light-emitting display device incorporates a semi-transmissive mirror pixel electrode made of aluminum alloy, along with a multi-layered metal structure and transparent conductive materials, and an MIM capacitor design, fabricated using a simplified five-mask process to enhance manufacturing efficiency and optical resonance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a conventional single-layer pixel electrode is used, then the manufacturing process is simpler, but the luminous efficiency and optical resonance are insufficient
Solution Approach 1:
The pixel electrode is divided into multiple layers (first pixel electrode layer and second pixel electrode layer) with different materials and functions. The first layer provides optical resonance enhancement while the second layer provides electrical conductivity, allowing each layer to be optimized for its specific function rather than requiring a single complex layer to perform all functions.
Solution Approach 2:
The patent employs composite material structure where the first pixel electrode layer uses a reflective material (such as aluminum alloy) and the second pixel electrode layer uses a transparent conductive material (such as ITO). This composite structure combines the optical properties of reflective materials with the electrical and optical transparency properties of TCMs, achieving both high luminous efficiency through optical resonance and good electrical conductivity.
2Use of energy by moving object
If aluminum alloy is used for pixel electrode to enhance optical resonance, then luminous efficiency improves, but transparent conductive layers may be damaged during patterning
Solution Approach 1:
The transparent conductive material layer is formed first before the aluminum alloy layer. This preliminary formation allows the TCM layer to be deposited and stabilized before the subsequent patterning process, reducing the risk of damage. The TCM layer serves as a protective and functional base layer that is already in place to support the optical resonance structure.
Solution Approach 2:
The patent transitions from a single-plane electrode structure to a multi-layer vertical structure. By stacking the TCM layer and aluminum alloy layer in different dimensions (layers), the patent achieves optical resonance enhancement while protecting the TCM layer from direct exposure to damaging patterning processes. The vertical arrangement allows the TCM layer to be shielded by the aluminum alloy layer during subsequent processing.
3Manufacturing precision
If multiple mask processes are used for precise patterning, then manufacturing precision improves, but the manufacturing complexity and time increase
Solution Approach 1:
The patent combines multiple patterning operations into a single unified process. By designing the pixel electrode and capacitor electrode patterns to be formed simultaneously through one mask process, the patent reduces the total number of mask steps required. This merging of operations maintains the necessary patterning precision while significantly simplifying the overall manufacturing process and reducing production time.
Solution Approach 2:
The mask pattern designed in the patent serves multiple functions simultaneously: it defines the pixel electrode pattern, defines the capacitor electrode pattern, and establishes the spatial relationship between different components. This universal mask design allows a single patterning step to achieve what would traditionally require multiple separate masking operations, reducing process complexity while maintaining 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 approach results in improved luminous efficiency, reduced manufacturing complexity, and enhanced circuit characteristics by enabling optical resonance and efficient patterning of the pixel electrode, while preventing damage to transparent conductive layers.
Implementation Method 1
The organic layer is on the pixel electrode and includes an organic emission layer
Implementation Method 2
An organic light-emitting display device that implements full-color images may employ an optical resonance structure that has different optical lengths at pixels with different colors
Implementation Method 3
The first pixel electrode includes a metal... The first metal may be an aluminum alloy
Data Source
AI summary
An organic light-emitting display device and a method of its manufacture are provided, whereby manufacturing processes are simplified and display quality may be enhanced. The display device includes: an active layer of a thin film transistor (TFT), on a substrate and including a semiconducting material; a lower electrode of a capacitor, on the substrate, doped with ion impurities, and including a semiconducting material; a first insulating layer on the substrate to cover the active layer and the lower electrode; a gate electrode of the TFT, on the first insulating layer; a pixel electrode on the first insulating layer; an upper electrode of the capacitor, on the first insulating layer; source and drain electrodes of the TFT, electrically connected to the active layer; an organic layer on the pixel electrode and including an organic emission layer; and a counter electrode facing the pixel electrode, the organic layer between the counter electrode and the pixel electrode.