LED Display Electrode Layout With Self-Alignment Against Short Defects
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Solution Overview
Problem
Existing display devices face challenges in minimizing or reducing short defects between electrodes, which can lead to misalignment and process errors, affecting the reliability and efficiency of the display.
Innovation Solution
A display device design that includes a substrate with sub-pixels, light emitting diodes with self-aligned first and second connection electrodes, and planarization layers to minimize short defects. The first planarization layer is filled in areas where the passivation film is torn, and the connection electrodes are self-aligned through an ashing process to ensure proper alignment without separate alignment processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If separate alignment processes are used for connection electrodes and light emitting diodes, then alignment precision can be improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The connection electrodes are designed to automatically align with the light emitting diodes through self-alignment mechanisms during the formation process, eliminating the need for separate alignment steps. The electrodes inherently position themselves relative to the LED structures through the layer formation and patterning processes, achieving precise alignment without additional alignment operations.
Solution Approach 2:
The connection electrodes are formed in advance during the layer formation process before final LED assembly, positioning them in predetermined locations that automatically align with the light emitting diodes. This preliminary positioning ensures accurate alignment is achieved as part of the standard fabrication sequence rather than requiring post-assembly alignment adjustments.
2Reliability
If planarization layers are added to separate electrodes and fill torn passivation areas, then short defects are reduced, but device complexity increases
Solution Approach 1:
The planarization layers serve multiple functions simultaneously: they provide surface flattening for subsequent layer deposition, electrically isolate different electrode regions to prevent short circuits, and fill in areas where the passivation film has been damaged or torn. By combining these three functions into a single layer structure, the design achieves reliable defect prevention without proportionally increasing overall device complexity.
3Manufacturing precision
If multiple planarization layers are used for self-alignment, then manufacturing precision improves, but ease of manufacture decreases
Solution Approach 1:
Multiple planarization layers are combined with electrode formation steps into an integrated fabrication sequence. Rather than adding separate planarization steps after electrode formation, the planarization layers are formed concurrently with the electrode layers through coordinated patterning and deposition processes. This merging achieves precise self-alignment while maintaining manufacturing efficiency by reducing the total number of discrete process steps.
Data Source
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AI summary
Provided is a display device. The display device includes a substrate including a plurality of sub pixels, a plurality of light emitting diodes which is disposed on the substrate in the plurality of sub pixels and each includes a first electrode and a second electrode disposed in a position higher than the first electrode, a first planarization layer which is disposed on the substrate so as to enclose a part of side surfaces of the plurality of light emitting diodes, a plurality of first connection electrodes which is disposed on the first planarization layer and is connected to the first electrode; a second planarization layer disposed on the first planarization layer and the plurality of first connection electrodes, and a plurality of second connection electrodes which is disposed on the second planarization layer and is connected to the second electrode. Therefore, the short defect may be minimized or reduced.