Journal of the Microelectronics and Packaging Society (마이크로전자및패키징학회지)

The Korean Microelectronics and Packaging Society (한국마이크로전자및패키징학회)
권호 표지
DOI QR코드

DOI QR Code

Scarf Welding of Thin Substrates and Evaluation of the Tensile Properties

박형 기판의 사면 접합 공정 및 인장 특성 평가

  • Beomseok Kang (Micro-Joining Center, Joining R&D Group, Korea Institute of Industrial Technology) ;
  • Jeehoo Na (Micro-Joining Center, Joining R&D Group, Korea Institute of Industrial Technology) ;
  • Myeong-Jun Ko (Micro-Joining Center, Joining R&D Group, Korea Institute of Industrial Technology) ;
  • Minjeong Sohn (Micro-Joining Center, Joining R&D Group, Korea Institute of Industrial Technology) ;
  • Yong-Ho Ko (Micro-Joining Center, Joining R&D Group, Korea Institute of Industrial Technology) ;
  • Tae-Ik Lee (Micro-Joining Center, Joining R&D Group, Korea Institute of Industrial Technology)
  • 강범석 (한국생산기술연구원 접합적층연구부문 마이크로조이닝센터) ;
  • 나지후 (한국생산기술연구원 접합적층연구부문 마이크로조이닝센터) ;
  • 고명준 (한국생산기술연구원 접합적층연구부문 마이크로조이닝센터) ;
  • 손민정 (한국생산기술연구원 접합적층연구부문 마이크로조이닝센터) ;
  • 고용호 (한국생산기술연구원 접합적층연구부문 마이크로조이닝센터) ;
  • 이태익 (한국생산기술연구원 접합적층연구부문 마이크로조이닝센터)
  • Received : 2023.09.15
  • Accepted : 2023.09.30
  • Published : 2023.09.30
Download PDF
⟨ Previous Next ⟩

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 ㎛ 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.

본 연구에서는 플렉서블 레이저 투과 용접 (flexible laser transmission welding, f-LTW)을 이용한 박형 기판의 사면 접합 (scarf welding) 공정을 개발하였다. 플렉서블 응용을 위해 경사면의 기울기에 따른 인장 강도의 거동을 조사하였다. 박형 기판으로써 100 ㎛ 이하 두께의 플라스틱 기판이 사용되었으며, 사면 접합을 위해서 기판의 말단에 경사면을 형성하는 지그 장치를 개발하였다. 플렉서블 고분자 기판에 대한 경사면 맞대기 접합을 개발함으로써 공정 후 접합부 두께가 증가하지 않는 유연 접합 기술 개발에 성공하였다. 단축 인장시험을 통해 접합부의 인장 강도를 평가하였으며, 그 결과 경사면의 기울기가 완만할수록 인장 강도가 증가함을 확인하였다. 경사각에 따른 접합 계면에서의 응력 분석을 수행하여 접합 구조 설계 인자를 규명하였다. 본 결과는 동일한 공정 조건에서 접합부의 형상에 따라서 인장 강도가 크게 달라질 수 있음을 시사하므로 접합 공정에서 접합부 형상을 고려하는 것에 대한 중요성을 확인할 수 있다.

Keywords

Acknowledgement

본 연구는 2023년 인천시 반도체 후공정 소부장 산업경쟁력 강화사업의 지원을 받아 수행된 연구 결과입니다.

References

  1. 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). https://doi.org/10.1002/j.2168-0159.2014.tb00090.x
  2. J. H. Souk, W. Lee, "A practical approach to processing flexible displays", Journal of the Society for Information Display, 18(4), 258 (2010).
  3. 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).
  4. S.-T. Han, H. Peng, Q. Sun, et al., "An overview of the development of flexible sensors", Advanced Materials, 29(33), 1700375 (2017).
  5. 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). https://doi.org/10.1146/annurev-bioeng-071811-150018
  6. 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).
  7. 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).
  8. 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).
  9. B. Duncan, "14 - Developments in Testing Adhesive Joints", Advances in Structural Adhesive Bonding, 389-436 (2010).
  10. 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). https://doi.org/10.1016/j.mseb.2006.02.046
  11. A. Karolak, J. Jasienko, K. Raszczuk, "Historical scarf and splice carpentry joints: state of the art", Heritage Science, 8(105), 1-19 (2020).
  12. 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). https://doi.org/10.1016/j.compstruct.2006.04.091
  13. J.-B. Souppez, "Experimental Testing of Scarf Joints and Laminated Timber for Wooden Boatbuilding Applications", International Journal of Maritime Engineering, 163(A3) (2021).
  14. 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). https://doi.org/10.1016/j.dt.2021.03.010
  15. C.-Y. Kang, "Design of Brazing joints(I)", Journal of Welding and Joining, 18(2), 11-13 (2000).
  16. 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). https://doi.org/10.1016/j.apsusc.2015.07.108