Micro-LED Sub-Pixel Repair Using Reflective Layer Isolation
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Solution Overview
Problem
Micro-LED display devices face challenges in accurately transferring micro-LEDs to their correct positions and minimizing defects, which can result in unreliable light emission and the occurrence of dark spots due to defective pixels.
Innovation Solution
A display device design featuring a reflective layer with a bottom portion and sidewall extending through the interlayer insulating film, allowing for accurate positioning of micro-LEDs and enabling selective electrical disconnection of defective micro-LEDs, thereby restoring normal sub-pixel functionality without removing the defective micro-LED from the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If micro-LEDs are transferred using a separate substrate, then the micro-LED display device can be manufactured, but defects occur in the micro-LED itself or in the transfer process resulting in unreliable light emission
Solution Approach 1:
The patent introduces a transfer substrate as an intermediary component between the micro-LED fabrication process and the final display device. This transfer substrate enables the micro-LEDs to be manufactured on a separate substrate and then transferred to the display device, resolving the contradiction by providing a controlled intermediate step that maintains both manufacturability and reliability
Solution Approach 2:
The patent performs preliminary actions by fabricating and testing micro-LEDs on a separate transfer substrate before transferring them to the final display device. This allows for defect detection and repair before the critical transfer process, improving reliability while maintaining ease of manufacture
2Ease of repair
If a defective micro-LED is removed from the substrate, then the defective pixel can be replaced, but the repair process becomes complex and time-consuming
Solution Approach 1:
The patent extracts the defective micro-LED from its original position on the transfer substrate and replaces it with a new micro-LED from a reservoir array. This extraction and replacement process is performed on the transfer substrate before final transfer, simplifying the repair process and reducing time loss
Solution Approach 2:
The patent uses a reservoir array containing multiple copies of micro-LEDs that can serve as replacements for defective ones. Instead of creating new micro-LEDs, pre-fabricated copies are used, significantly reducing repair time and complexity
3Ease of manufacture
If the transfer process is performed to move micro-LEDs to correct positions, then the display device can be assembled, but dark spots occur due to defects in the transfer process
Solution Approach 1:
The patent performs preliminary detection and repair of defective micro-LEDs on the transfer substrate before the final transfer process. This preliminary action prevents defective micro-LEDs from being transferred to the display device, eliminating dark spots while maintaining assembly feasibility
Solution Approach 2:
The patent implements a feedback mechanism where the status of micro-LEDs is detected on the transfer substrate, and repair actions are taken based on this feedback before final transfer. This closed-loop approach ensures that only functional micro-LEDs are transferred, preventing dark spot formation
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 approach improves the accuracy of micro-LED placement, reduces the occurrence of dark spots, and enhances the efficiency of the display device by allowing for simultaneous repair of multiple defective pixels without damaging surrounding micro-LEDs.
Implementation Method 1
a reflective layer having a bottom portion disposed on the substrate and extending horizontally and a sidewall portion upwardly extending from the bottom portion and extending through the interlayer insulating film in an inclined manner
Data Source
AI summary
A display device and a repairing method in the method are disclosed. The display device includes a substrate; a plurality of sub-pixels formed on the substrate; and a data line and a common voltage line disposed on each sub-pixel. Each of the plurality of sub-pixels includes a thin-film transistor; a first and second light-emitting elements that are adjacent to each other and spaced from each other; a first electrode connecting the first light-emitting element and the second light-emitting element to the common voltage line; and a second electrode connecting the first light-emitting element and the second light-emitting element to a drain electrode of the thin-film transistor, wherein the drain electrode is connected to the data line.