LED Supply Substrate Defect Replacement for Batch Display Transfer
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Solution Overview
Problem
Existing methods for producing light emitting diode (LED) displays face challenges in transferring a large number of normal LEDs to a display panel substrate efficiently, as defective LEDs on the supply substrate are often transferred, leading to reduced yield and the need for rearrangement of normal LEDs.
Innovation Solution
A method involving a selective removal step to identify and remove defective LEDs from the supply substrate, followed by a second mounting step to transfer normal LEDs to the positions of the defective ones, using a laser lift-off technique, ensuring only normal LEDs are transferred to the display panel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If collective transfer of light emitting diodes is performed from supply substrate to display panel substrate, then productivity is improved, but defective LEDs are transferred along with normal LEDs, reducing reliability
Solution Approach 1:
The patent applies preliminary action by performing defect detection and selective removal of defective LEDs from the supply substrate before the collective transfer process. This ensures that only normal LEDs are transferred to the display panel substrate, maintaining high reliability while preserving the productivity benefits of collective transfer.
Solution Approach 2:
The patent segments the transfer process into distinct stages: (1) defect detection of individual LEDs on the supply substrate, (2) selective removal of defective LEDs, and (3) collective transfer of only normal LEDs. This segmentation allows quality control to be integrated into the high-speed collective transfer process without compromising productivity.
2Manufacturing precision
If stamp method is used for transferring light emitting diodes, then manufacturing precision is improved, but the process requires excessive time and labor for individual transfer operations
Solution Approach 1:
The patent merges the advantages of both stamp method and collective transfer by combining precise positioning capabilities with batch processing. The system maintains the precision of individual placement while achieving the speed of collective transfer through automated defect detection and selective removal before transfer.
Solution Approach 2:
The patent replaces manual or mechanical individual transfer operations with an automated system that uses optical detection for defect identification and automated mechanisms for selective removal and transfer. This substitution eliminates the time-consuming nature of individual transfer operations while maintaining precision.
3Speed
If laser lift-off method with separation layer is used, then transfer speed is improved, but material adheres to devices requiring additional cleaning steps
Solution Approach 1:
The patent changes the material parameters of the separation layer by selecting materials with specific properties that prevent adhesion to the LED surfaces. This parameter change allows the laser lift-off method to proceed at high speed without leaving residual material that would require cleaning, thus resolving the contradiction between transfer speed and ease of manufacture.
4Quantity of substance
If supply substrate contains defective light emitting diodes, then production cost is reduced, but normal LEDs must be rearranged on display panel substrate
Solution Approach 1:
The patent applies self-service by implementing automated defect detection and selective removal systems that automatically identify and eliminate defective LEDs from the supply substrate before transfer. This self-service approach prevents defective LEDs from reaching the display panel, eliminating the need for manual rearrangement work while maintaining high LED density.
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 significantly reduces LED defects and enhances the yield of producing LED displays by ensuring only normal LEDs are used, allowing for high-efficiency transfer and assembly of LED displays.
Implementation Method 1
the laser light 6 passes through the starting substrate 1 and reaches the vicinity of the interface between the surface of the starting substrate 1 and the light emitting diodes 2, so that the GaN on the side of the light emitting diodes 2 in the vicinity of this interface is thinly subjected to the laser ablation
Implementation Method 2
there is a method that utilizes the pressure-sensitive adhesive properties of PDMS (PolyDiMethylSiloxane), which is a silicone resin
Data Source
AI summary
A method for producing a light emitting diode supply substrate for transferring a plurality of light emitting diodes to a supply destination, including: a first mounting step of mounting a plurality of light emitting diodes on a supply substrate; a selective removal step of selectively removing defective light emitting diodes on the supply substrate, and a second mounting step of transferring a normal light emitting diode to a position where the defective light emitting diode has been arranged on the supply substrate. Thus, a method produces a light emitting diode supply substrate capable of producing a light emitting diode supply substrate capable of transferring a plurality of normal light emitting diodes to a supply destination.