마이크로전자및패키징학회지 (Journal of the Microelectronics and Packaging Society)

  • 제29권2호
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  • Pages.113-119
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  • 2022
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  • 1226-9360(pISSN)
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  • 2287-7525(eISSN)
한국마이크로전자및패키징학회 (The Korean Microelectronics and Packaging Society)
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플렉서블 기판의 레이저 투과 용접 및 기계적 특성 평가

Laser Transmission Welding of Flexible Substrates and Evaluation of the Mechanical Properties

  • 고명준 (한국생산기술연구원 접합적층연구부문 마이크로조이닝센터) ;
  • 손민정 (한국생산기술연구원 접합적층연구부문 마이크로조이닝센터) ;
  • 김민수 (한국생산기술연구원 접합적층연구부문 마이크로조이닝센터) ;
  • 나지후 (한국생산기술연구원 접합적층연구부문 마이크로조이닝센터) ;
  • 주병권 (고려대학교 전기전자공학부 디스플레이 및 나노시스템 연구실) ;
  • 박영배 (안동대학교 신소재공학부 청정에너지소재기술연구센터) ;
  • 이태익 (한국생산기술연구원 접합적층연구부문 마이크로조이닝센터)
  • Ko, Myeong-Jun (Micro-Joining Center, Joining R&D Group, Korea Institute of Industrial Technology) ;
  • Sohn, Minjeong (Micro-Joining Center, Joining R&D Group, Korea Institute of Industrial Technology) ;
  • Kim, Min-Su (Micro-Joining Center, Joining R&D Group, Korea Institute of Industrial Technology) ;
  • Na, Jeehoo (Micro-Joining Center, Joining R&D Group, Korea Institute of Industrial Technology) ;
  • Ju, Byeong-Kwon (Display and Nanosystem Laboratory, School of Electrical Engineering, Korea University) ;
  • Park, Young-Bae (School of Materials Science and Engineering, Andong National University) ;
  • Lee, Tae-Ik (Micro-Joining Center, Joining R&D Group, Korea Institute of Industrial Technology)
  • 투고 : 2022.06.20
  • 심사 : 2022.06.30
  • 발행 : 2022.06.30
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초록

플렉서블, 웨어러블 디바이스 등을 포함한 차세대 전자 기기의 기계적 신뢰성 향상을 위하여 다양한 유연 접합부에서 높은 수준의 기계적 신뢰성이 요구되고 있다. 기존 고분자 기판 접합을 위한 에폭시 등의 유기 접착소재는 접합부 두께 증가가 필연적이며, 반복 변형, 고온 경화에 의한 열기계적 파손 문제를 수반한다. 따라서 유연 접합을 위해서 접합부 두께를 최소화하고 열 손상을 방지하기 위한 저온 접합 공정 개발이 요구된다. 본 연구에서는 플렉서블 기판의 유연, 강건, 저 열 손상 접합이 가능한 플렉서블 레이저 투과 용접(flexible laser transmission welding, f-LTW)를 개발하였다. 유연 기판 위 탄소나노튜브(carbon nanotube, CNT)를 박막 코팅하여 접합부 두께를 줄였으며, CNT 분산 빔 레이저 가열을 통한 고분자 기판 표면의 국부적 용융 접합 공정이 개발되었다. 짧은 접합 공정 시간과 기판의 열 손상을 최소화하는 레이저 공정 조건을 구축하였으며 고분자 기판과 CNT 접합 형성 메커니즘을 분석하였다. 또한 접합부의 강건성 및 유연성 평가를 위해 인장강도 시험, 박리 시험과 반복 굽힘 시험을 진행하였다.

In order to improve the mechanical reliability of next-generation electronic devices including flexible, wearable devices, a high level of mechanical reliability is required at various flexible joints. Organic adhesive materials such as epoxy for bonding existing polymer substrates inevitably have an increase in the thickness of the joint and involve problems of thermodynamic damage due to repeated deformation and high temperature hardening. Therefore, it is required to develop a low-temperature bonding process to minimize the thickness of the joint and prevent thermal damage for flexible bonding. This study developed flexible laser transmission welding (f-LTW) that allows bonding of flexible substrates with flexibility, robustness, and low thermal damage. Carbon nanotube (CNT) is thin-film coated on a flexible substrate to reduce the thickness of the joint, and a local melt bonding process on the surface of a polymer substrate by heating a CNT dispersion beam laser has been developed. The laser process conditions were constructed to minimize the thermal damage of the substrate and the mechanism of forming a CNT junction with the polymer substrate. In addition, lap shear adhesion test, peel test, and repeated bending experiment were conducted to evaluate the strength and flexibility of the flexible bonding joint.

키워드

과제정보

이 연구는 2022년 산업통상자원부 및 한국산업기술평가관리원(KEIT)의 글로벌 시장 진출을 위한 스마트 자동차용 고신뢰성/고해상도 센싱 카메라 전장모듈의 접합 소재/공정 기술 개발(20016230) 과제 연구비 지원으로 수행되었습니다.

참고문헌

  1. M.-R. Kim, U. Hong and E. -H. Kim, "A Study on the Utilization of Flexible Display based on Bernd H. Schmitt's Experience Module-Focus on Package Design", The monthly packaging world, 19(2), 65-81 (2022).
  2. A. Schindler, J. Brill, N. Fruehauf, J. P. Novak and Z. Yaniv, "Solution-deposited Carbon Nanotube Layers for Flexible Display Applications", Physica E. Low Dimens. Syst. Nanostruct., 37(1-2), 119-123 (2007). https://doi.org/10.1016/j.physe.2006.07.016
  3. J. Chang, G. Liang, A. Gu, S. Cai and L. Yuan, "The Production of Carbon Nanotube/epoxy Composites with a Very High Dielectric Constant and Low Dielectric Loss by Microwave Curing", Carbon, 50(2), 689-698 (2012). https://doi.org/10.1016/j.carbon.2011.09.029
  4. 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 (in Kor.)", J. Microelectron. Packag. Soc., 28(2), 89-94 (2021). https://doi.org/10.6117/KMEPS.2021.28.2.089
  5. M. D. Banea, F. S. M. De Sousa, L. F. M. Da Silva, R. D. S. G. Campilho and A. B. de Pereira, "Effects of Temperature and Loading Rate on the Mechanical Properties of a High Temperature Epoxy Adhesive", J. Adhes. Sci. Technol., 25(18), 2461-2474 (2011). https://doi.org/10.1163/016942411X580144
  6. L. Zhou, A. Wanga, S. C. Wu, J. Sun, S. Park, and T. N. Jackson, "All-organic Active Matrix Flexible Display", Appl. Phys. Lett., 88(8), 083502 (2006). https://doi.org/10.1063/1.2178213
  7. H. J. Nam, J. Y. Lim, C. H. Lee and S. H. Park, "Development of Epoxy Based Stretchable Conductive Adhesive (in Kor.)", J. Microelectron. Packag. Soc., 27(3), 49-54 (2020). https://doi.org/10.6117/KMEPS.2020.27.3.049
  8. E. Vazquez, M. Prato, "Carbon Nanotubes and Microwaves: Interactions, Responses, and Applications", ACS Nano, 3(12), 3819 (2009) https://doi.org/10.1021/nn901604j
  9. W. W. Duley and R. E. Mueller. "CO2 Laser Welding of Polymers", Polym. Eng. Sci., 32(9), 582-585(1992). https://doi.org/10.1002/pen.760320903
  10. B. Acherjee, "Laser Transmission Welding of Polymers - A Review on Welding Parameters, Quality Attributes, Process Monitoring, and Applications", Journal of Manufacturing Processes, 64, 421-443 (2021). https://doi.org/10.1016/j.jmapro.2021.01.022
  11. B. Acherjee, "Laser Transmission Welding of Polymers - A Review on Process Fundamentals, Material Attributes, Weldability, and Welding Techniques", Journal of Manufacturing Processes, 60, 227-246 (2020). https://doi.org/10.1016/j.jmapro.2020.10.017
  12. J. Bai, R. D. Goodridge, R. J. Hague and M. Song, "Improving the Mechanical Properties of Laser-sintered Polyamide 12 through Incorporation of Carbon Nanotubes", Polym. Eng. Sci., 53(9), 1937-1946 (2013). https://doi.org/10.1002/pen.23459
  13. F. Duerr, and H. Thienpont, "Analytic Design of a Zoom XY-beam Expander with Freeform Optical Surfaces", Opt. Express, 23(23), 30438-30447 (2015). https://doi.org/10.1364/OE.23.030438
  14. Y. Nakamura, Y. Suzuki and Y. Watanabe, "Effect of Oxygen Plasma Etching on Adhesion Between Polyimide Films and Metal", Thin Solid Films, 290, 367-369 (1996). https://doi.org/10.1016/S0040-6090(96)09017-7
  15. Z. Wu, N. Xanthopoulos, F. Reymond, J. S. Rossier and H. H. Girault, "Polymer Microchips Bonded by O2-plasma Activation", Electrophoresis 23(5), 782-790 (2002). https://doi.org/10.1002/1522-2683(200203)23:5<782::AID-ELPS782>3.0.CO;2-K
  16. G. Kim, J. Lee, S. H. Park, S. Kang, T. S. Kim and Y. B. Park, "Comparison of Quantitative Interfacial Adhesion Energy Measurement Method between Copper RDL and WPR Dielectric Interface for FOWLP Applications", J. Microelectron. Packag. Soc., 25(2), 41-48 (2018). https://doi.org/10.6117/KMEPS.2018.25.2.041
  17. M. F. De Volder, S. H. Tawfick, R. H. Baughman and A. J. Hart, "Carbon Nanotubes: Present and Future Commercial Applications", science 339(6119), 535-539 (2013). https://doi.org/10.1126/science.1222453
  18. Y. -C. Kim, "Durability and Driving Characteristics of Flexible Electronic Paper Display Using CNT Electrode", Journal of Convergence for Information Technology, 12(2), 127-133 (2022).
  19. S. I. Na, S. S. Kim, J. Jo, and D. Y. Kim, "Efficient and Flexible ITO-free Organic Solar Cells using Highly Conductive Polymer Anodes", Adv. Mater., 20(21), 4061-4067 (2008). https://doi.org/10.1002/adma.200800338