Pattern Transfer Printing Alignment for High-Throughput Wafer Printing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pattern transfer printing technologies face challenges in achieving high accuracy, efficiency, and throughput in producing photovoltaic cells, particularly in aligning and transferring conductive patterns onto wafers.
Innovation Solution
A pattern transfer printing (PTP) system and method that includes a tape handling unit for controlled delivery of pattern transfer sheets, a paste filling unit for precise filling of trenches, a wafer handling unit for parallelized wafer delivery, and a paste transfer unit using laser illumination for non-contact printing, along with monitoring and quality control mechanisms to enhance alignment and print quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional pattern transfer printing is used, then the process can be implemented with existing technology, but the alignment accuracy and print quality are insufficient
Solution Approach 1:
The patent replaces conventional mechanical contact-based printing methods with laser-induced forward transfer (LAFT) technology. The laser beam (optical field) is used to vaporize the donor layer and transfer the patterned material to the substrate without mechanical contact, thereby achieving higher alignment accuracy and print quality while reducing mechanical system complexity
Solution Approach 2:
The patent employs real-time monitoring and dynamic adjustment of process parameters including laser power, pulse duration, scanning speed, and stage positioning. These parameter optimizations enable precise control of the transfer process, achieving sub-micrometer alignment accuracy and high print quality
2Manufacturing precision
If high accuracy alignment is achieved through monitoring, then the print quality improves, but the production throughput decreases
Solution Approach 1:
The patent implements a continuous scanning laser system with real-time feedback control. The laser beam continuously scans across the donor layer while the stage moves at controlled speeds, allowing uninterrupted transfer operations. The system maintains continuous monitoring of transfer quality and dynamically adjusts parameters without stopping production, ensuring both high print quality and sustained throughput
Solution Approach 2:
The system performs preliminary alignment and characterization of the donor layer using optical microscopy and image processing before the actual transfer begins. This pre-positioning and quality assessment ensure that subsequent transfer operations proceed without interruptions for realignment, maintaining both accuracy and throughput
3Manufacturing precision
If laser illumination is used for non-contact printing, then the alignment accuracy and paste transfer efficiency improve, but the energy consumption increases
Solution Approach 1:
The patent employs pulsed laser operation with optimized pulse duration and frequency. The laser delivers energy in short, high-intensity pulses rather than continuous illumination, allowing the material to vaporize and transfer efficiently while minimizing total energy consumption. The pulse parameters are tuned to achieve complete transfer with minimal excess energy input
Solution Approach 2:
The laser beam is focused to a small spot size and scanned only across the regions containing the patterned material that needs to be transferred. This localized energy application avoids unnecessary heating and energy consumption in surrounding areas, improving paste transfer efficiency while reducing overall energy usage
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 system improves the quality, accuracy, and throughput of pattern transfer printing by enabling precise alignment, efficient paste transfer, and continuous operation, facilitating the production of high-quality photovoltaic cells.
Implementation Method 1
transferred the conductive printing paste from the pattern transfer sheets onto the delivered wafers, by releasing the printing paste from the trenches upon illumination by a laser beam
Data Source
Figure 1A
Figure 1B~1C
Figure 2A
AI summary
Pattern transfer printing (PTP) systems and methods are provided to improve the quality, accuracy and throughput of pattern transfer printing. PTP systems comprise a tape handling unit for handling a tape with pattern transfer sheets sections and for controllably delivering the pattern transfer sheets one-by-one for paste filling and consecutively for pattern transfer, with the tape moving from an unwinder roll to a re-winding roll. PTP systems further comprise a paste filling unit which enables continuous paste filling using a supporting counter roll opposite to the paste filling head, a wafer handling unit controllably delivering wafers for the pattern transfer in a parallelized manner that increases throughput, a paste transfer unit with enhanced accuracy and efficiency due to exact monitoring and wafer alignment, as well as a print quality control unit.