Multi-Layer Signal Lines Prevent COG Scratching in OLED Displays
Solution Overview
Problem
In the manufacturing of organic light emitting displays using the multi-panel process, signal lines under the COG region are prone to shorting due to scratches from glass particles during the scribing process, leading to errors in driving the organic light emitting devices.
Innovation Solution
The signal lines are formed such that the first signal line is on the gate insulation film and the second signal line is on the interlayer insulation film, allowing for the transmission of different or the same signals, thereby preventing short circuits and ensuring proper operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the COG region is used in the multi-panel process with scribing, then productivity is improved, but the signal lines are scratched by glass particles causing short circuits
Solution Approach 1:
The signal lines are segmented into two separate layers: the first signal line is formed on the gate insulation film, and the second signal line is formed on the interlayer insulation film. This segmentation ensures that even if one layer is scratched during the scribing process, the other layer remains intact and functional, thus preventing short circuits while maintaining manufacturing efficiency.
Solution Approach 2:
The solution moves from a single-layer signal line configuration to a multi-layer configuration by placing signal lines on different vertical levels (different dimensions). The first signal line is positioned at a lower level on the gate insulation film, while the second signal line is positioned at a higher level on the interlayer insulation film, creating dimensional separation that prevents shorting.
2Device complexity
If signal lines are formed on a single layer, then device complexity is reduced, but short circuits occur during scribing
Solution Approach 1:
The signal line function is segmented across two separate layers instead of using a single complex protective structure. This segmentation distributes the risk of short circuits across multiple independent paths, maintaining simplicity in each individual layer while achieving reliability through the multi-layer configuration.
Solution Approach 2:
Instead of increasing complexity within a single layer, the solution adds a vertical dimension by creating signal lines on two different levels. This dimensional approach resolves the contradiction by providing redundancy without significantly increasing the complexity of individual signal line structures.
Data Source
Figure 1~2
Figure 3~4
AI summary
An organic light emitting display is provided. In the organic light emitting display, when a wiring section (30) including a plurality of signal lines (32,34) for transmitting signals to a driving circuit unit or an organic light emitting device is formed under a non-display region, more specifically, a COG region where a driving IC is mounted, the signal lines (32,34) of the wiring section (30) are disposed on two or more different layers (14b,14d) to maintain a height difference between neighboring signal lines (32,34) for transmitting different signals from each other.