Roller Transfer Method for Micro LED Pitch Expansion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current manufacturing processes for micro LED displays face challenges in rapidly and massively expanding the pitch of micro devices due to the small thickness and precision requirements, with existing electrostatic picking/placing techniques being complex and costly for mass production.
Innovation Solution
A two-step roller transfer method involving a first substrate with micro devices, a first roller with contact line portions, a temporary substrate rotated 90 degrees, and a second roller, utilizing adhesive layers to transfer and expand the pitch of micro devices to a third substrate, enabling simple and low-cost mass production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional individual bonding method is used, then position precision can be maintained, but production speed is too slow for mass production
Solution Approach 1:
The invention segments the transfer process into multiple stages using a multi-roller system. Each roller handles a portion of the pitch expansion, dividing the complex task of transferring micro-LEDs from small pitch to large pitch into manageable steps while maintaining precision and speed
Solution Approach 2:
The invention introduces intermediate rollers with specific pitch patterns as mediators in the transfer process. These rollers act as temporary carriers that facilitate the transition from source substrate to target substrate, enabling rapid transfer while maintaining position precision through controlled adhesive release
2Length of moving object
If electrostatic picking/placing techniques are used, then pitch expansion can be achieved, but device complexity and cost increase
Solution Approach 1:
The invention replaces complex electrostatic mechanisms with a simpler mechanical roller-based system. The rollers use controlled adhesion and release mechanisms to achieve pitch expansion without requiring sophisticated electrostatic fields or complex control systems
Solution Approach 2:
The invention changes the pitch parameter progressively through multiple roller transfers. Each roller is designed with a specific pitch pattern that gradually expands the spacing between micro-LEDs, achieving the desired pitch expansion through cumulative parameter changes rather than a single complex operation
3Productivity
If rapid high-precision mechanisms are used, then pitch expansion speed can be improved, but overall cost for mass production increases
Solution Approach 1:
The invention combines multiple functions into a single integrated roller system. The rollers simultaneously perform pitch expansion, transfer, and positioning functions, eliminating the need for separate mechanisms and reducing overall system cost while maintaining high-speed operation
Solution Approach 2:
The invention uses periodic adhesive release and reattachment cycles as rollers rotate through the system. This periodic action enables continuous high-speed transfer of micro-LEDs without requiring complex real-time control, simplifying the mechanism while maintaining rapid production capability
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 method allows for rapid and massive pitch expansion of micro devices, addressing the limitations of existing technologies by simplifying the process and reducing costs, making it suitable for mass production in micro LED display manufacturing.
Implementation Method 1
a first adhesive layer is provided between the first substrate and the micro devices... a second adhesive layer is provided on surfaces of the contact line portions... a third adhesive layer is provided on a surface of the second substrate
Data Source
AI summary
A transfer method for expanding pitches of devices includes: providing a first substrate with micro devices having the pitches being a predetermined value in a first direction and a second direction; transferring the micro devices to a first roller by contacting it with the micro devices, wherein a pitch of contact line portions on the first roller is N times of the predetermined value; transferring the micro devices on the first roller to a second substrate; rotating the second substrate by 90 degrees; transferring the micro devices to a second roller by rolling the second roller to contact the micro devices; and then transferring the micro devices to a third substrate to expand the pitch of the micro devices in both the first and the second directions. The portions in contact with the micro devices all have adhesive layers with different adhesion operation windows.