Flat Panel Display Power Supply Line Grid Structure
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Solution Overview
Problem
Active matrix organic electroluminescent display devices face issues with voltage drops and inline shorts between the power supply line and other conductive lines, leading to nonuniform luminance and increased manufacturing costs due to complex process steps.
Innovation Solution
The power supply line is formed on a separate layer from the data and gate lines, using a low-resistance, high-reflectivity material, and is created simultaneously with the anode electrode in a single deposition and patterning step, minimizing the risk of shorts and voltage drops by ensuring uniform power distribution across pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the power supply line is formed on the same layer as data and gate lines, then the manufacturing process is simpler, but the risk of inline shorts increases
Solution Approach 1:
The power supply line is moved from the same plane as data and gate lines to a different layer (dimension), specifically formed on the same layer as the anode electrode while data and gate lines remain on separate layers. This spatial separation in the vertical dimension eliminates the risk of inline shorts while maintaining manufacturing efficiency through simultaneous formation processes.
2Reliability
If the power supply line is formed on a separate layer from data and gate lines, then the risk of inline shorts is reduced, but the manufacturing process becomes more complex
Solution Approach 1:
The power supply line formation process is merged with the anode electrode formation process by forming both structures simultaneously on the same layer using the same material deposition and patterning steps. This consolidation eliminates additional manufacturing complexity while achieving the reliability benefit of separate layering from data and gate lines.
Solution Approach 2:
The same conductive material layer serves multiple functions: it forms both the power supply line and the anode electrode for the EL device. This multi-functionality approach allows the power supply structure to be created without adding separate process steps, maintaining manufacturing simplicity while achieving spatial separation for reliability.
3Ease of manufacture
If conventional materials are used for the power supply line, then the manufacturing cost is lower, but voltage drops occur leading to nonuniform luminance
Solution Approach 1:
The electrical parameters of the power supply line are optimized by selecting materials with specifically low resistivity (such as aluminum, silver, or copper) and designing appropriate line widths and patterns. These parameter changes reduce voltage drops along the power supply line, ensuring uniform power delivery to all pixels and achieving uniform luminance while remaining cost-effective.
Solution Approach 2:
The power supply line structure may employ composite material approaches, such as combining highly conductive metal layers with transparent conductive oxide layers, to achieve both low resistance for uniform power distribution and compatibility with subsequent EL device fabrication processes, thereby maintaining luminance uniformity without excessive cost.
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 voltage drops and prevents inline shorts, achieving uniform luminance across pixels while simplifying the manufacturing process and reducing costs by combining process steps.
Implementation Method 1
using a low-resistance, high-reflectivity material
Implementation Method 2
formed simultaneously and on the same layer as the anode electrode for the EL device
Data Source
AI summary
A flat panel display capable of preventing inline short between adjacent wirings and voltage drop through power supply line by using pixel electrode layer as a power supply layer, and a fabrication method thereof. A flat panel display of the present invention is made up of a thin film transistor including source/drain electrodes, formed on an insulation substrate, an insulation film formed on the insulation substrate including the thin film transistor and including first and second contact holes for exposing the source/drain electrodes respectively, a pixel electrode formed on the insulation film and connected to one of the source/drain electrodes through one of the first and second contact holes, and a power supply layer formed on the insulation film and connected to the other one of the source/drain electrodes through the other one of the first and second contact holes. Losses in the power supply line is reduced by forming the power supply line of a low resistivity material and by providing the power supply line in a grid structure.