Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-23T08:56:37.206Z Has data issue: false hasContentIssue false

Effect of drop impact energy on contact resistance of anisotropic conductive adhesive film joints

Published online by Cambridge University Press:  03 March 2011

Rashed Adnan Islam
Affiliation:
Department of Electronic Engineering, City University of Hong Kong, Kowloon Tong, Kowloon, Hong Kong
Y.C. Chan*
Affiliation:
Department of Electronic Engineering, City University of Hong Kong, Kowloon Tong, Kowloon, Hong Kong
B. Ralph
Affiliation:
Faculty of Technology and Information Systems, Brunel University, Uxbridge, Middlesex UB8 3PH, United Kingdom
*
a) Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

The contact resistances investigated in this study of anisotropic conductive adhesive film joints using Au/Ni bumps and flexible substrates are found to be increased by the drop impact energy and also by the combined effect of heat/humidity and the impact energy. The samples humidified at 85 °C/85% RH for 384 h, on which impact energy of 50 J was induced, exhibit the most severe results. The contact resistance increases by 700%, which had been about 0.062 Ω in the as-bonded condition. The samples without humidification showed a sluggish and gentle increase in contact resistance with induced drop impact energy. The contact resistance was found to be increased by 400% after absorbing 90 J energy. Scanning electron microscopy images show particle deformation due to abrasion and friction between the contacting surfaces resulting from the sudden impact. Joints are also observed with no connections, which signify open circuits. Almost 25% of circuits were found open in the samples (after 384 h in a humid environment), which have suffered severe mechanical shock. Breaking of the conductive layer of the particle and exposing the underlying polymeric portion was also observed.

Type
Articles
Copyright
Copyright © Materials Research Society 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1Fu, Y., Willander, M. and Liu, J.: Statistic of electric conductance through anisotropically conductive adhesive. IEEE Transactions on Components and Packaging Technologies 24, 250 (2000).Google Scholar
2Chang, D.D., Fulton, J.A., Lyons, A.M. and Nis, J.R. Design considerations for the implementation of anisotropically conductive adhesive interconnections, Proc. of Nepcon W , 1992 , p. 1381.Google Scholar
3Yim, M. and Paik, K.: Design and understanding of ACFs for LCD packaging. IEEE Transactions on Components and Packaging Technology-Part A 21, 226 (1998).Google Scholar
4Nagai, A., Takemure, K., Isaka, K., Watanabe, O., Kojima, K., Matsuda, K. and Watanabe, I. Anisotropic conductive adhesive films for flip chip interconnection onto organic substrates. In Proceedings of IEMT/IMC , 1998 , p. 353.Google Scholar
5Aschenbrenner, R., MieBner, R. and Reichl, H.: Adhesive flip chip bonding on flexible substrates. J. Electron Manufact. 7, 245 (1997).CrossRefGoogle Scholar
6Aschenbrenner, R., Ostmann, A., Motulla, G., Zakel, E. and Reichl, H.: Flip chip attachment using anisotropic conductive adhesives and electroless nickel bumps. IEEE Trans CPMT – Part C 20, 96 (1997).Google Scholar
7Zwolinski, M., Hickman, J, Rubon, H., and Zaks, Y.: Electrically conductive adhesives for surface mount solder replacement. In Proceedings of the 2nd International Conference on Adhesive Joining & Coating Technology in Electronic Manufacturing, Stockholm, Sweden, June 3–5, 1996, pp. 333340.Google Scholar
8 D. Lu, Q.K. Tong, and C.P. Wong: Mechanisms underlying the unstable resistance of conductive adhesives, In Proceedings of the 49th Electronic Components and Technology Conference, 1999, pp. 347352.Google Scholar
9Rosen, S.L.Fundamental Principles of Polymeric Materials, Second Edition (John Wiley & sons, New York, 1993).Google Scholar
10Klempner, D., Sperling, L.H. and Utracki, L.A.: Interpenetrating Polymer Networks , Advances in Chemistry Series 239 (American Chemical Society, Washington, DC, 1994).CrossRefGoogle Scholar
11 D. Lu and C.P. Wong: Conductive adhesives for solder replacement in electronic packaging. In Proceedings of the 2000 International Symposium on Advanced Packaging Materials, 2000, pp. 2431.Google Scholar
12Liu, J. and Lundstorm, P. Manufacturability, reliability, and failure mechanism in conductive adhesive joining for flip chip and surface mount applications. In Conductive adhesive for electronic packaging , edited by Liu, J. (1999), pp. 212253.Google Scholar
13Tan, C.W., Chan, Y.C. and Yeung, N.H.Effect of autoclave test on anisotropic conductive joints, Microelectronic Reliabilit y 43, 279 (2003).CrossRefGoogle Scholar