Micro-LED Electrode Structure to Prevent Magnetic Agglomeration
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Solution Overview
Problem
The self-assembly method for micro-LEDs in large-area displays faces challenges due to agglomeration phenomena, where adjacent micro-LEDs stick together due to magnetic layers, leading to reduced assembly speed, yield, and lighting efficiency, as well as electrical connection defects.
Innovation Solution
A semiconductor light emitting device design featuring a light emitting layer with a magnetic layer on the side surfaces and an insulating layer with round surfaces, preventing agglomeration by allowing micro-LEDs to move individually and ensuring proper assembly without sticking, thereby improving assembly speed and yield and enhancing lighting efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a magnetic layer is disposed on the lower side of the micro-LED to enable movement by magnet, then the micro-LED can be moved to desired location in fluid, but agglomeration phenomenon occurs where adjacent micro-LEDs stick to each other
Solution Approach 1:
The magnetic layer is segmented into multiple separate magnetic regions on the lower surface of the micro-LED, with non-magnetic spaces between them. This prevents continuous magnetic contact between adjacent micro-LEDs, eliminating the agglomeration phenomenon while maintaining individual movement capability through magnetic field application.
Solution Approach 2:
A non-magnetic insulating layer is introduced between the magnetic layer and the substrate, acting as an intermediary that prevents direct magnetic adhesion between adjacent micro-LEDs while allowing the magnetic field to still exert force for movement. This mediator eliminates the harmful agglomeration effect.
2Quantity of substance
If multiple micro-LEDs are pulled by magnets with small distance between them, then assembly density increases, but agglomeration phenomenon occurs reducing assembly speed
Solution Approach 1:
The magnetic layer is divided into separate magnetic regions with non-magnetic spaces, allowing micro-LEDs to be densely packed without forming agglomerates. Each micro-LED can still be individually manipulated by the magnet through the segmented magnetic regions, maintaining high assembly speed.
Solution Approach 2:
The magnetic attraction is applied partially through segmented regions rather than continuously across the entire surface. This partial action allows dense packing of micro-LEDs while preventing the excessive magnetic adhesion that causes agglomeration and slows assembly.
3Force
If magnetic layers of adjacent micro-LEDs face each other with large contact area, then magnetic attraction between micro-LEDs increases, but proper assembly becomes difficult
Solution Approach 1:
The magnetic layer is segmented into separate regions with non-magnetic spaces between them, reducing the contact area between adjacent micro-LEDs. This segmentation maintains sufficient magnetic attraction for movement while preventing the strong adhesion that would prevent proper assembly positioning.
Solution Approach 2:
Different regions of the magnetic layer have different properties - magnetic regions provide attraction force while non-magnetic regions provide separation. This local quality variation allows the system to simultaneously achieve sufficient magnetic attraction for movement and adequate separation for precise assembly.
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
The design prevents agglomeration, allowing for faster and more accurate assembly of micro-LEDs, improving assembly yield, and reducing electrical connection defects, which enhances the overall performance and efficiency of micro-LED displays.
Implementation Method 1
the micro-LEDs are moved to a desired location in the fluid using a magnet that generates a magnetic field
Implementation Method 2
the corresponding micro-LEDs are assembled on the substrate by the electric field. The electric field is generated by the voltage applied to the assembling wiring provided on the substrate
Data Source
AI summary
A semiconductor light emitting device includes a light emitting layer, a first electrode on a lower side of the light emitting layer, a second electrode on an upper side of the light emitting layer, an insulating layer on a side portion of the light emitting layer and overlapping at least a portion of the first electrode and overlapping at least a portion of the second electrode and a plurality of metal layers spaced apart from each other in the insulating layer, the plurality of metal layers including a first metal layer including a reflective layer and a second metal layer including a magnetic layer.