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@PHDTHESIS{Chung:1022447,
      author       = {Chung, Woo-Sik},
      othercontributors = {Häfner, Constantin Leon and Reisgen, Uwe},
      title        = {{I}ncrease of joint area by gap-bridging laser beam welding
                      on metalized substrates; 1. {A}uflage},
      school       = {Rheinisch-Westfälische Technische Hochschule Aachen},
      type         = {Dissertation},
      address      = {Aachen},
      publisher    = {Apprimus Verlag},
      reportid     = {RWTH-2025-10031},
      isbn         = {978-3-98555-312-9},
      series       = {Ergebnisse aus der Lasertechnik},
      pages        = {1 Online-Ressource : Illustrationen},
      year         = {2025},
      note         = {Druckausgabe: 2025. - Auch veröffentlicht auf dem
                      Publikationsserver der RWTH Aachen University 2026. -
                      Weitere Reihe: Lasertechnik; Dissertation,
                      Rheinisch-Westfälische Technische Hochschule Aachen, 2025},
      abstract     = {Increasing performance and the associated junction
                      temperature in the field of power electronics require new
                      packaging and connection technology. Besides conventional
                      soldering and ultrasonic welding, the novel “Laser Impulse
                      Metal Bonding” (LIMBO) process opens up possibilities to
                      meet these requirements in electronic packaging. The
                      gap-bridging LIMBO process enables a weld joint on thermally
                      sensitive substrates by thermal separation of the joining
                      partners. The gap bridging is realized by melt pool
                      deflection due to a sudden expansion of the vapor capillary
                      in the melt using temporal laser beam modulation. However,
                      to avoid a thermal overload, a certain distance is required
                      between each LIMBO weld joint. Therefore, the number of
                      welds that can be applied to a limited surface area is yet
                      restricted for the LIMBO process. This affects the resulting
                      weld joint cross-section.In this thesis, an overlap welding
                      approach is investigated to extend the limited weld joint
                      area with the LIMBO process. In addition to the process
                      fundamentals, this thesis describes an analytical model for
                      melt pool deflection, thermal simulations, and experimental
                      studies on heat transfer. This enables a continuous weld
                      joint cross-section of more than 0.2 mm² despite the
                      thermal bridge between the two joining partners caused by
                      the previous welding process. The resulting weld joint
                      generated with the extended LIMBO process has a larger weld
                      joint cross-section, which improves the mechanical and
                      electrical properties. The material specifications are
                      considered for the process development to avoid exceeding
                      the thermal destruction threshold during the welding
                      process. This work thus provides a basic understanding of
                      function-oriented contacting solutions for different printed
                      circuit boards and metal-ceramic substrates.},
      cin          = {418710},
      ddc          = {620},
      cid          = {$I:(DE-82)418710_20140620$},
      typ          = {PUB:(DE-HGF)11 / PUB:(DE-HGF)3},
      doi          = {10.18154/RWTH-2025-10031},
      url          = {https://publications.rwth-aachen.de/record/1022447},
}