OLED Pad Electrode Pitch Expansion via Bridge Electrode Merging
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Solution Overview
Problem
As the resolution of OLED displays increases, the number of pad electrodes increases, reducing their pitch and leading to potential short circuits during the grinding process of glass substrates, which results in defective drives and reduced reliability.
Innovation Solution
A display device design that includes a substrate with a display portion and a pad portion, featuring power lines and data lines connected by bridge electrodes on the same layer as the shield layer, with fewer power pad electrodes than power lines, and auxiliary electrodes between data lines, to increase the pitch of pad electrodes and prevent short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of pad electrodes is increased to support higher resolution, then the display resolution is improved, but the pitch of pad electrodes is reduced leading to short circuits
Solution Approach 1:
Multiple power lines are merged and connected to a single bridge electrode, which then connects to multiple power pad electrodes. This consolidation reduces the total number of pad electrodes required while maintaining the functionality of multiple power lines, thereby increasing the pitch between remaining pad electrodes and preventing short circuits during grinding
Solution Approach 2:
The bridge electrode serves as an intermediary component between multiple power lines and multiple power pad electrodes. It consolidates multiple power line connections into a single interface point with the pad, reducing the number of direct pad electrode connections needed and increasing the pitch of remaining pad electrodes
2Adaptability or versatility
If the number of pad electrodes is increased to support more signal lines, then the display functionality is improved, but the pitch of pad electrodes is reduced
Solution Approach 1:
Multiple power lines are merged into a single bridge electrode connection, reducing the total number of pad electrodes needed and thereby increasing the pitch of remaining pad electrodes while maintaining support for multiple signal lines
3Adaptability or versatility
If the pitch of pad electrodes is reduced to accommodate more electrodes, then the signal line connectivity is improved, but the manufacturing precision is reduced due to short circuits
Solution Approach 1:
Multiple power lines are consolidated into a single bridge electrode interface, reducing the number of pad electrodes and increasing the pitch between them. This larger pitch prevents short circuits during the grinding process while maintaining the ability to support multiple signal lines
Solution Approach 2:
The bridge electrode acts as an intermediary that consolidates multiple power line connections into a single point of contact with the pad, reducing the number of grinding operations needed and preventing short circuits that would occur with closely spaced pad electrodes
4Adaptability or versatility
If the number of pad electrodes is increased, then the display portion functionality is improved, but the device complexity is increased
Solution Approach 1:
Multiple power lines are merged into a single bridge electrode connection, reducing the total number of pad electrodes and simplifying the pad electrode structure while maintaining the functionality to support multiple signal lines and display operations
Data Source
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AI summary
A display device for preventing a defective drive and improving reliability is disclosed. The display device includes a substrate (SUB) including a display portion (A/A) and a pad portion outside the display portion (A/A), a plurality of power lines (VL1 to VL5) positioned on the pad portion of the substrate (SUB) and extended from the display portion (A/A), a plurality of data lines (DL1 to DL5) positioned in parallel with the plurality of power lines (VL1 to VL5) and extended from the display portion (A/A), and a plurality of bridge electrodes (LSP) configured to connect at least two of the plurality of power lines (VL1 to VL5). Some (VL1, VL5) of the plurality of power lines (VL1 to VL5) include a power pad electrode (VPE1, VPE2) on at least an end of the corresponding power line (VL1, VL5), and a number of the power pad electrodes (VPE1, VPE2) is less than a number of the power lines (VL1 to VL5).