2:00pm - 2:30pmInvited Talk: Advanced Approaches to Direct Laser-Assisted Fabrication of Metal Micropatterns Using Diverse Precursors
Ilya Tumkin1, Mizue Mizoshiri2, Evgenia M. Khairullina3, Lev Logunov4, Evgeny Gurevich5, Andreas Ostendorf1
1Ruhr University, Bochum, Germany; 2Nagaoka University of Technology, Nagaoka, 940-2188, Japan; 3St. Petersburg State University, Russia; 4School of Physics and Engineering, ITMO University, Russia; 5Laser Center (LFM), University of Applied Sciences Münster, Steinfurt, Germany
The metallization of dielectrics and polymeric materials has recently attracted growing attention due to its critical role in advancing microelectronics, particularly in the fabrication of flexible devices. Direct Laser Metallization (DLM) encompasses a broad spectrum of techniques that utilize laser radiation to induce the reduction of metal ions and their subsequent deposition onto substrates. This work provides a comprehensive investigation of the processes occurring at the "substrate–precursor" interface during laser irradiation, focusing on the formation of conductive structures. Both one- and two-step approaches utilize precursors of diverse chemical nature, including aqueous solutions of metal salts and complexes, ionic precursors based on deep eutectic solvents (DES)—a unique class of viscous media—as well as inks containing metal oxide nanoparticles (NPs). The research highlights the distinctive characteristics and potential of these methods for the development of flexible and wearable electronic devices.
2:30pm - 2:45pmThe effect of laser emission mode on the cutting of lithium metal as a solid-state battery anode
Pourya Heidari Orojloo1, Pantaleone Barbieri2, Daniela Fontana2, Ali Gökhan Demir1
1Department of Mechanical Engineering, Politecnico di Milano, Via La Masa 1, 20156 Milan, Italy; 2Comau S.p.A. – E-Mobility Global Competence Center, Via Rivalta 30, 10095 Grugliasco, Italy
Lithium metal as an anode in the solid-state battery is a promising alternative to the intercalation type of anode in the lithium-ion battery. However, cutting of this component mechanically is challenging due to its high surface adhesion, chemical reactivity, and low rigidity. On the other hand, the melting temperature of this material is very low (180 °C) compared to conventional metals, rendering it problematic a stable thermal cutting operation. While the laser is an appealing solution for scaling up the cutting process of lithium metal, the ideal laser type to be used for this operation still requires further attention. Accordingly, this work investigates impact of continuous wave and ns-pulsed laser sources on the cut quality and productivity of 50 µm-thick pure Li sheets. Processing conditions are discussed to address the environmental control issues for reactivity along with the different processing regimes observed.
2:45pm - 3:00pmFrom Macro to Micro: Multimode Fiber Lasers in Direct Laser Interference Patterning
Bogdan Voisiat1, Wei Wang2, Dominik Britz2, Andrés Fabian Lasagni1,3
1Technische Universität Dresden, Germany; 2SurFunction GmbH, Germany; 3Fraunhofer Institute for Material and Beam Technology IWS, Germany
This study highlights a groundbreaking advancement in Direct Laser Interference Patterning (DLIP) by integrating a high-power multimode fiber laser, traditionally used for macro fabrication, into precision microfabrication processes. By employing an innovative beam-shaping system, the challenges associated with the low coherence and beam quality of multimode lasers are effectively addressed, enabling the generation of well-defined periodic structures on large surface areas. This novel approach demonstrates the feasibility of utilizing multimode fiber lasers for high-resolution microstructuring, thus marking a significant shift in their application scope. The findings open new opportunities for integrating these versatile and high-power lasers into industrial-scale microfabrication, offering efficiency, scalability, and precision.
3:00pm - 3:15pmLithium-ion battery foil cutting processes optimized with an infrared ultrashort pulse laser and megahertz pulse bursts
Jim Bovatsek, Markus Ruetering, Terence Hollister
MKS Instruments, Inc. / Spectra-Physics, United States of America
Laser cutting of electrode foils is a critical step in Li-ion battery manufacturing, with high single-pass speeds along with excellent quality being required. While demands have previously been met by infrared fiber laser technology, producers are increasingly turning to high-power ultrashort pulse (USP) lasers as quality requirements continue to increase. In this work, we present results for laser cutting graphite-based anode and NMC cathode battery materials. The foils are ~100 µm thick and double-side coated with the respective active material. Using 200 watts of IR femtosecond laser power, single-pulse cutting processes were developed and optimized, followed by a burst-optimization scheme using the laser’s flexible pulse-tailoring capability. When bursts were optimally applied, cutting speeds improved by up to ~45%. Analysis includes optical and scanning electron microscopy, with particular attention given to the cut edge quality and the amount of excess active coating material removal.
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