Korean Journal of Materials Research (한국재료학회지)

Materials Research Society of Korea (한국재료학회)
권호 표지
DOI QR코드

DOI QR Code

Influence of ITO Thickness on the Deformation and Cracking Behaviors of ITO/PET Sheets

ITO층의 두께에 따른 ITO/PET sheet의 변형거동 및 균열 형성 거동

  • Kim, Jin-Yeol (Department of Advanced-materials Engineering, Chungnam National University) ;
  • Hong, Sun-Ig (Department of Advanced-materials Engineering, Chungnam National University)
  • 김진열 (충남대학교 신소재공학과) ;
  • 홍순익 (충남대학교 신소재공학과)
  • Published : 2009.01.31
Download PDF
⟨ Previous Next ⟩

Abstract

In this study, the stress-strain response and the cracking behaviors of ITO film on a PET substrate are investigated. The cracking behaviors of ITO thin films deposited on a thermoplastic semi-crystalline polymer developed for flexible display applications was investigated by means of tensile experiments equipped with an electrical measurement apparatus and an in-situ optical microscope. Electrical resistance increased gradually in the elastic-to-plastic transition region of the stress strain curves and cracks formed. Numerous cracks were found in this region, and the increase of the resistance was linked to the cracking of ITO thin films. Upon loading, the initial cracks perpendicular to the tensile axis were observed at about 1% of the total strain. They propagated to the entire sample width as the strain increased. The spacing between the horizontal cracks is thought to be determined by the fracture strength and the thickness of the ITO film as well as by the interfacial strength between the ITO and PET. The effect of the strain rate on the cracking behavior was also investigated. The crack density increased as the strain increased. The spacing between the horizontal cracks (perpendicular to the stress axis) increased as the strain rate decreased. The increase of the crack density as the strain rate decreased can be attributed to the higher fraction of the plastic strain to the total strain at a given total strain. The higher critical strain for the onset of the increase in the resistance and the crack initiation of the ITO/PET with a thinner ITO film (300 ohms/sq.) suggests a higher strength of the thinner ITO film.

Keywords

References

  1. J. T. Hwang, J. M. Son, I. N. Kang and Y. S. Bu, Polym. Sci. Technol., 14(5), 554 (2003)
  2. T. L. Li and S. L. C. Hsu, Eur. Polym. J., 43, 3368 (2007) https://doi.org/10.1016/j.eurpolymj.2007.04.039
  3. B. J. Cho and K. H. Kim, J. of KIEEME, 20(2), 162 (2007)
  4. T. Minami, H. Sonohara, T. Kakumu and S. Takata, Thin Solid films, 270, 32 (1995)
  5. S. M. Kim, Y. S. Rim, H. W. Choi, M. G. Choi, K. H. Kim, J. of KIEEME, 21(7), 669 (2008)
  6. Y. Leterrier, L. Medico, F. Demarco, J.A.E. Manson, U. Betz, M. F. Escola, M. K. Olsson and F. Atamny, Thin Solid Films, 460, 156 (2004) https://doi.org/10.1016/j.tsf.2004.01.052
  7. S. Grego, J. Lewis, E. Vick and D. Temple, Thin Solid Films, 515, 4745 (2007) https://doi.org/10.1016/j.tsf.2006.11.034

Cited by

  1. Crack density and electrical resistance in indium-tin-oxide/polymer thin films under cyclic loading vol.10, pp.6, 2014, https://doi.org/10.1007/s13391-014-3321-5
  2. Prediction of crack density and electrical resistance changes in indium tin oxide/polymer thin films under tensile loading vol.24, pp.4, 2015, https://doi.org/10.1177/1056789514539362