Fan-Shaped Lead Array Substrate for LCD Mura Prevention
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Solution Overview
Problem
Existing liquid crystal display (LCD) panels experience uneven display issues (mura) due to the uneven diffusion of polyimide (PI) liquid, caused by the V-shaped common electrode blocking the PI liquid, resulting in thicker film thickness and dark display abnormalities at the intersection points of fan-out leads.
Innovation Solution
The array substrate design includes fan-shaped leads with a common electrode and connection lines that extend perpendicularly, forming diversion lines between the effective display region and the peripheral lead region, ensuring the PI liquid can diffuse uniformly, thereby homogenizing the film thickness and preventing mura.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a V-shaped common electrode is used to block PI liquid diffusion at the fan-out lead intersection, then the electrode structure is simplified and manufacturing is easier, but the PI liquid diffusion becomes uneven causing thicker film thickness and mura display defects
Solution Approach 1:
The common electrode is segmented into multiple parts: a first common electrode in the display area, a second common electrode in the peripheral lead region, and a bridge portion connecting them. This segmentation allows the PI liquid to diffuse uniformly across the entire common electrode structure without being blocked by a continuous V-shaped design, while still maintaining the simplified manufacturing process.
Solution Approach 2:
Different regions of the common electrode are designed with different properties. The first common electrode in the display area has specific shape characteristics, while the second common electrode in the peripheral lead region has different characteristics to facilitate PI liquid diffusion. The bridge portion is specifically designed to connect these regions and enable uniform PI liquid distribution, creating local quality variations that solve the overall diffusion problem.
2Area of stationary object
If fan-out leads are concentrated toward the driving chip to reduce non-display area, then the display area is increased, but the PI liquid diffusion is blocked at the intersection points causing uneven film thickness and mura phenomena
Solution Approach 1:
The common electrode structure is divided into multiple segments that extend into the peripheral lead region, with bridge portions connecting them. This segmentation creates multiple diffusion paths for the PI liquid, allowing it to reach all areas uniformly even when fan-out leads are concentrated, thus maintaining both large display area and uniform film thickness.
Solution Approach 2:
The common electrode extends not only in the display area but also into the peripheral lead region in a different spatial dimension. The bridge portions connect electrodes at different locations, creating a three-dimensional diffusion network that allows PI liquid to bypass the fan-out lead intersections and achieve uniform distribution across the entire structure.
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 design effectively prevents the uneven diffusion of PI liquid, improving the display quality by ensuring consistent film thickness and eliminating mura phenomena, enhancing the overall performance of the LCD panel.
Implementation Method 1
the V-shaped common electrode 400 will block the PI liquid diffusing in a certain extent, so that the PI liquid cannot normally diffuse outward at this location
Data Source
AI summary
An array substrate and a display panel includes an effective display region and a peripheral lead region; at least two sets of fan-shaped leads are formed on the peripheral lead region and are juxtaposably disposed and spaced apart along a first direction, a common electrode is between the adjacent two sets of the fan-shaped leads, and a plurality of connection lines extend from an edge of the effective display region; the common electrode includes a lateral section; a distance between the lateral section and the effective display region is greater than 500 μm; the connection line and the common electrode constitute into a plurality of diversion lines extending along the second direction on a section between the lateral section and the effective display region.