2024

Vol.31 No.2

Current Issue Archives
Search
Advanced Search
Editorial Office

Review

  • Journal of the Microelectronics and Packaging Society
  • Volume 30(3); 2023
  • Article

Review

Journal of the Microelectronics and Packaging Society 2023;30(3):102-110. Published online: Nov, 9, 2023

PDF Full Text XML

DOI : doi.org/10.6117/kmeps.2023.30.3.0102

Scarf Welding of Thin Substrates and Evaluation of the Tensile Properties

  • Beomseok Kang, Jeehoo Na, Myeong-Jun Ko, Minjeong Sohn, Yong-Ho Ko, and Tae-Ik Lee†
    Micro-Joining Center, Joining R&D Group, Korea Institute of Industrial Technology, Incheon 21999, Korea
Corresponding author E-mail: tilee@kitech.re.kr
Abstract

This paper introduces scarf welding process of thin substrates using flexible laser transmission welding (f-LTW) technology. We examined the behavior of tensile strength relative to the scarf angle for flexible applications. Thin plastic substrates with the thickness of less than 100 μm were bonded and a jig to form a slope at the edge of the substrate was developed. By developing the scarf welding process, we successfully created a flexible bonding technology that maintains joint’s thickness after the process. The tensile strength of the joint was assessed through uniaxial test, and we found that the tensile strength increases as the slope of bonding interface decreases. By conducting stress analysis at the bonding interface with respect to the slope angle, design factor of bonding structure was investigated. These findings suggest that the tensile strength depends on the geometry of the joint, even under the same process conditions, and highlights the significance of considering the geometry of the joint in welding processes.

Keywords thin substrate, scarf welding, laser bonding, stress analysis

REFERENCES
  • S. Hong, C. Jeon, S. Song, J. Kim, J. Lee, D. Kim, S. Jeong, H. Nam, J. Lee, W. Yang, "Development of commercial flexible AMOLEDs", SID Symposium Digest of Technical Papers, 45, 334-337 (2015).
  • J. H. Souk, W. Lee, "A practical approach to processing flexible displays", Journal of the Society for Information Display, 18(4), 258 (2010).
  • T. Sekine, R. Sugano, T. Tashiro, K. Fukuda, D. Kumaki, F. D. Dos Santos, A. Miyabo, S. Tokito, "Fully printed and flexible ferroelectric capacitors based on a ferroelectric polymer for pressure detection", Japanese Journal of Applied Physics, 55(10S) (2016).
  • S.-T. Han, H. Peng, Q. Sun, et al., "An overview of the development of flexible sensors", Advanced Materials, 29(33), 1700375 (2017).
  • D.-H. Kim, R. Ghaffari, N. Lu, J. A. Rogers, "Flexible and Stretchable Electronics for Biointegrated Devices", Annual Review of Biomedical Engineering, 14(1), 113-128 (2012).
  • T. T. Luong, Z. Chen, H. Zhu, "Flexible Solar Cells based on Copper Phthalocyanine and Buckminsterfullerene", Solar Energy Materials and Solar Cells, 94(6), (2010).
  • M. Sohn, M.-S. Kim, B.-K. Ju, and T.-I. Lee, "Room-temperature Bonding and Mechanical Characterization of Polymer Substrates using Microwave Heating of Carbon Nanotubes", J. Microelectron. Packag. Soc., 28(2), 89-94 (2021).
  • M.-J. Ko, M. Sohn, M.-S. Kim, J. Na, B.-K. Ju, Y.-B. Park, and T.-I. Lee, "Laser Transmission Welding of Flexible Substrates and Evaluation of the Mechanical Properties", J. Microelectron. Packag. Soc., 29(2), 113-119 (2022).
  • B. Duncan, "14 - Developments in Testing Adhesive Joints", Advances in Structural Adhesive Bonding, 389-436 (2010).
  • S. B. Kumar, I. Sridhar, S. Sivashanker, S. O. Osiyemi, A. Bag, "Tensile Failure of Adhesively Bonded CFRP Composite Scarf Joints", Materials Science and Engineering: B, 132(1-2), 113-120 (2006).
  • A. Karolak, J. Jasienko, K. Raszczuk, "Historical scarf and splice carpentry joints: state of the art", Heritage Science, 8(105), 1-19 (2020).
  • A. B. Harman, C. H. Wang, "Improved Design Methods for Scarf Repairs to Highly Strained Composite Aircraft Structure", Composite Structures, 75(1-4), 132-144 (2006).
  • J.-B. Souppez, "Experimental Testing of Scarf Joints and Laminated Timber for Wooden Boatbuilding Applications", International Journal of Maritime Engineering, 163(A3) (2021).
  • D. Sethi, U. Acharya, S. Shekhar, B. S. Roy, "Applicability of unique scarf joint configuration in friction stir welding of AA6061-T6: Analysis of torque, force, microstructure and mechanical properties", Defence Technology, 18(4), 567-582 (2022).
  • C.-Y. Kang, "Design of Brazing joints(I)", Journal of Welding and Joining, 18(2), 11-13 (2000).
  • Y. J. Kang, H. Chung, M.-S. Kim, W. Kim, "Enhancement of CNT/PET film adhesion by nano-scale modification for flexible all-solid-state supercapacitors", Applied Surface Science, 355, 160-165 (2015).