Micro LED Sub-Pixel Circuit Layout for Vertical Chip Repair
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Solution Overview
Problem
The production yield of flip-chip processes in high-resolution micro LED display devices is reduced, and the manufacturing time and cost are increased due to the difficulty of photolithography processes in vertical chip repairing.
Innovation Solution
A micro LED display device with a circuit substrate and sub-pixel units, where each unit includes a first and a second light-emitting element with different electrical properties. The second element is connected in parallel with the first and overlaps with the circuit projections, allowing for repair without additional photolithography for electrode connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If flip-chip process is used for high-resolution micro LED display, then display resolution is improved, but production yield is reduced
Solution Approach 1:
The light-emitting element is divided into two separate electrodes (first electrode and second electrode) that can be independently transferred and connected to the circuit substrate. This segmentation allows each electrode to be optimally positioned and connected without the constraints of traditional flip-chip bonding, thereby maintaining high resolution while improving production yield through easier repair and replacement processes.
2Productivity
If vertical chip technology is used for high-resolution micro LED display, then production yield is improved, but manufacturing time and cost are increased due to additional photolithography processes
Solution Approach 1:
The circuit pattern is pre-formed on the circuit substrate before the light-emitting elements are transferred. The first and second circuits are already in place, allowing the electrodes to be directly connected upon transfer without requiring additional photolithography processes. This preliminary preparation of the circuit substrate significantly reduces manufacturing time and cost while maintaining high production yield.
3Reliability
If vertical chip technology is used for repairing micro LED display, then reliability is improved, but manufacturing cost is increased due to additional photolithography processes
Solution Approach 1:
The light-emitting elements with their electrodes are extracted as separate, independently transferable units. This allows damaged elements to be removed and replaced without requiring complex photolithography processes to create new conductive paths. The pre-formed circuit substrate with first and second circuits enables direct connection of replacement elements, significantly reducing repair cost while maintaining reliability.
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 design enhances production yield and reduces manufacturing time and cost by enabling effective repair of failed elements without additional photolithography processes.
Implementation Method 1
micro LED display device includes a circuit substrate, a circuit pattern and a plurality of sub-pixel units... each sub-pixel unit includes at least one first light-emitting element and a second light-emitting element
Data Source
AI summary
In a micro LED display device, a circuit pattern includes multiple first and second circuits. At least one of multiple sub-pixel units includes a first light-emitting element and a second light-emitting element. The first light-emitting element has a first electrode connected to one first circuit and a second electrode connected to one second circuit. The projection of at least one of the first electrode and the second electrode on the circuit substrate is away from the projection of electrically connected first or second circuit. The second light-emitting element has a luminous color the same as that of the first light-emitting element, and is electrically connected to one of the first circuits and one of the second circuits and in parallel with the first light-emitting element. The projection of the second light-emitting element on the circuit substrate overlaps with the projection of electrically connected first and second circuits.