Journal of the Korean Society for Precision Engineering

Laser Ablation Patterning of Metal Thin Films for On-demand of Shadow Mask Patterning in Vacuum Deposition: Beomsun Do, Seunghun Lee, Hyunho Lee, Hoon Jeong, Joel Ndikumana, Kunsik An; J. Korean Soc. Precis. Eng. 2025;42(10):775-782.
Published online October 1, 2025; DOI: https://doi.org/10.7736/JKSPE.D.25.00001

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This study explores the use of laser ablation technology for creating on-demand shadow masks, which are essential in the fabrication of thin film transistor (TFT) devices. Traditional methods for producing shadow masks often encounter significant challenges, such as high costs, lengthy production times, and difficulties in achieving fine, high-resolution patterns. To address these issues, this study introduces a method for manufacturing shadow masks using fiber laser-based laser ablation. Key laser parameters, including frequency and power, were optimized throughout the research. Systematic experimentation revealed that a frequency of 20 kHz and a power output of 14 W enabled the precise and uniform creation of patterns with a 50 μm channel spacing. When these custom shadow masks were employed in the TFT fabrication process, the resulting devices exhibited stable and reliable electrical performance. The findings suggest that laser ablation-based on-demand shadow mask technology offers a cost-effective and flexible solution for producing large-area, high-resolution TFTs. Additionally, this approach significantly reduces the prototyping cycle, making it ideal for rapid development and iterative testing in research and development environments.

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Analysis of the Laser Ablation Threshold of Aluminum Foil under Varying Relative Humidity Conditions: Myeongho Park, Dongkyoung Lee; J. Korean Soc. Precis. Eng. 2025;42(7):537-542.
Published online July 1, 2025; DOI: https://doi.org/10.7736/JKSPE.025.064

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To reduce the use of fossil fuels, the adoption of battery electric vehicles (BEVs) using lithium-ion batteries has been increasing in internal combustion engine alternatives. Accordingly, significant efforts have been made to improve the manufacturing process of lithium-ion batteries within electric vehicles. In particular, the cutting process of lithium-ion batteries has been actively discussed as it is closely related to battery performance. Laser-based cutting enables a more precise and sustainable manufacturing process. The laser ablation threshold has been investigated in many studies to achieve high-precision laser processing. While laser parameters and ambient conditions have been examined to determine the laser ablation threshold, studies focusing on the effect of relative humidity remain insufficient. Thus, this study investigated the laser ablation threshold of aluminum foil under varying relative humidity conditions. First, a laser interaction chamber was fabricated to control the relative humidity during experiments. A scanning electron microscope (SEM) was then used to observe laser ablation craters and analyze the threshold. The variation of the laser ablation threshold with relative humidity revealed changes in the interaction between the laser and aluminum foil depending on the humidity level.

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Development of Laser Ablation Integrated Simulation Program for Windows with Visual Fortran and OpenGL: Se Yoon Bang; J. Korean Soc. Precis. Eng. 2017;34(11):797-805.
Published online November 1, 2017; DOI: https://doi.org/10.7736/KSPE.2017.34.11.797

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An integrated simulation program for virtual laser ablation is developed to help understand and predict the effects of machining parameters on the final machined results. The main solver of the program is based on the model for polymer ablation with short-pulse Excimer lasers. The GUI of the program is built using Visual Fortran and OpenGL so that the user can work in a visual environment, such as Windows on a PC, where the important machining parameters can be input via a dialog box and the calculated results for the machined shape can be plotted by means of a 3D graphics window using OpenGL. The developed GUI can be implemented for use with most pre-developed FORTRAN solvers for Windows application, allowing the user to control the input parameters and to see the results in a 3D plot; hence most FORTRAN users could create their own visual programs on PC Windows systems similarly, widening the range of application of FORTRAN solvers.