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Fundamental Study on Adhesion of Epoxy Underfill Materials with Passivation Layer in Flip-chip Packaging

Published online by Cambridge University Press:  21 March 2011

Shijian Luo
Affiliation:
Packaging Research Center School of Materials Science and Engineering Georgia Institute of Technology Atlanta, GA 30332, USA
C. P. Wong
Affiliation:
Packaging Research Center School of Materials Science and Engineering Georgia Institute of Technology Atlanta, GA 30332, USA
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Abstract

The influence of aging in an environment with a high temperature and a high humidity on the adhesion performance of underfill material (epoxy cured with acid anhydride) to the passivation layer in flip chip packaging is discussed. Adhesion of underfill to different passivation materials degrades after aging in a high temperature and high humidity environment. The extent of this degradation is dependent on the hydrophilicity of the passivation material. Hydrophilic passivation such as silicon oxide (SiO2) and silicon nitride (Si3N4) shows much more severe adhesion degradation than hydrophobic passivation such as benzocyclobutene (BCB) and polyimide (PI). The mobility of absorbed water and of polymer chains is studied with solid state nuclear magnetic resonance (NMR) spectroscopy. Higher mobility of absorbed water and of polymer chains in rubbery state polymers contributes to faster adhesion degradation during high temperature and high humidity aging. The adhesion stability of hydrophilic passivation can be successfully improved by use of a silane coupling agent that introduces stable chemical bond at interface. A flow micro-calorimeter was used to study the absorption of silane coupling agent onto glass surface. The difference in adhesion retention improvement between aminosilane and epoxysilane is discussed.

Type
Research Article
Copyright
Copyright © Materials Research Society 2001

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References

REFERENCES

1. Wong, C. P., Luo, Shijian, and Zhang, Zhuqing, “Flip the Chip”, Science, Vol. 290, Dec. 22, 2000, pp.22692270.Google Scholar
2. Vroonhoven, J. C. W. van, “Effects of Adhesion and Delamination on Stress Singularityies in Plastic-packaged Integrated Circuits,” Journal of Electronic Packaging 1993, 115, 2832.Google Scholar
3. Shi, S., Ph.D. Dissertation, Georgia Institute of Technology, 2000.Google Scholar
4. Luo, Shijian and Wong, C. P., “Study on Effect of Coupling Agents on Underfill Material in Flip Chip Packaging”, IEEE Transactions on Components and Packaging Technologies, Vol. 24(1), 2001, pp. 3842.Google Scholar
5. Lam, D. C. C., Yang, F., and Tong, P., “Chemical Kinetic Model of Interfacial Degradation of Adhesive Joints,” IEEE Transactions on Components and Packaging Technology, vol. 22, 1999, pp. 215220.Google Scholar
6. Wong, E. H., Chan, K. C., Rajoo, R., and Lim, T. B., “The Mechanics and Impact of Hygroscopic Swelling of Polymeric Materials in Electronic Packaging”, Proceedings of 50th Electronic Components and Technology Conference, 2000, pp. 576580.Google Scholar
7. Wong, C. P. and McBride, R., “Pre-encapsulation Cleaning Methods and Control for Microelectronics Packaging”, IEEE Transactions on Components, Packaging, and Manufacturing Technology – Part A, Vol. 17(4), 1994, pp. 542552.Google Scholar
8. Luo, S., Wong, C. P., Leisen, J., “Fundamental Study on Moisture Absorption in Epoxy for Electronic Application”, in Proceedings of International symposium and Exhibition on Advance Packaging Materials: Process, Properties and Interfaces, Braselton, GA, 2001, pp. 293298.Google Scholar
9. Andrews, E. H., in Adhesive Bonding, edited by Lee, Lieng-Huang, Plenum Press, New York, 1991, p.337.Google Scholar
10. Welsh, D. J., Pearson, R. A., Luo, S. and Wong, C. P., “Fundamental Study on Adhesion Improvement for Underfill Using Adhesion Promoter”, in Proceedings of 51st Electronic Components and Technology Conference, 2001.Google Scholar