Segmented Source-Drain Metal Lines for OLED Charge Accumulation
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Solution Overview
Problem
In organic light-emitting display devices, charges can accumulate on source-drain metal lines after dry etching, leading to a difference in charge amount between gate and source-drain metal lines, which can cause thin-film transistor breakdown and current or voltage leakage.
Innovation Solution
Breaking the first source-drain metal line into short portions spaced by a predefined spacing and connecting adjacent portions to form a mesh structure with second source-drain metal lines in a different layer, thereby reducing the charge difference and preventing transistor breakdown.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the first source-drain metal line is extended continuously in the row direction, then power signals can be supplied to all pixels, but charges accumulate on the metal line causing transistor breakdown and leakage
Solution Approach 1:
The first source-drain metal line is divided into multiple short portions (first, second, third portions) spaced apart from each other. Each portion is independently connected to pixel circuits, preventing charge accumulation while maintaining continuous power supply capability across the display panel.
2Object-generated harmful factors
If the first source-drain metal line is broken into short portions, then charge accumulation is reduced, but the structure becomes more complex requiring additional connection lines
Solution Approach 1:
The patent introduces a second source-drain metal line in a different layer that connects to the first source-drain metal line portions. This vertical connection in the third dimension (through contact holes) simplifies the overall structure by providing alternative current paths without requiring complex planar routing.
3Adaptability or versatility
If gate metal lines and source-drain metal lines are used for signal transmission, then display functionality is achieved, but charge difference between lines causes leakage
Solution Approach 1:
The patent applies different structural characteristics to different metal lines: gate metal lines remain continuous for signal transmission, while source-drain metal lines are segmented into portions. This local differentiation allows each line type to optimize its function without causing charge accumulation-related leakage.
Data Source
AI summary
Disclosed is a display device in which a first source-drain metal line that supplies each of power signals (VOBS, Vini, VAR) to a display panel is broken into short portions spaced from each other by a predefined spacing, such that a difference between a charge amount of a gate metal line and a charge amount of the first source-drain metal line is prevented from increasing. To this end, respective short portions of the first source-drain metal lines adjacent to each other are connected to each other through a second source-drain metal line disposed in a different layer from a layer of the first source-drain metal lines, such that the first source-drain metal lines and the second source-drain metal lines intersect each other to constitute a mesh structure in a plan view of the display device.