Skip to main content
SpringerLink
Log in

Shear strength of Sn–3.5Ag solder bumps formed on Ni/Au and organic solderability preservative surface-finished bond pads after multiple reflow steps

  • Article
  • Published:
Journal of Materials Research Aims and scope Submit manuscript

Abstract

Sn–3.5Ag solder bumps were formed on electroless Ni/immersion Au (Ni/Au) and organic solderability preservative (OSP) surface-finished bond pads, respectively. The shear strength of the solder bumps was measured as a function of reflow steps. Fracture surfaces and interfacial microstructures were investigated by scanning electron microscope. The shear strength of Ni/Au samples increased up to the seventh reflow step and subsequently decreased after the tenth reflow step. Spalling of Ni3Sn4 intermetallic compounds (IMCs) and the P-rich Ni layer strengthened and weakened the bond, respectively. For OSP samples, although Cu6Sn5 IMCs grew as the reflow step was repeated, no remarkable change in shear strength was observed. Interfacial fractures of OSP samples occurred at the interface between Cu6Sn5 IMC and Cu3Sn IMC. Fracture surfaces of OSP samples showed concave pits that consisted of a Cu3Sn bottom and an Sn wall. The pits were formed by separation of Cu6Sn5 IMC from Cu3Sn IMC and the molten Sn channel between the Cu6Sn5 IMC grains.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. S.K. Kang, D.Y. Shih, K. Fogel, P. Lauro, M.J. Yim, G.G. Advocate Jr. M. Griffin, C. Goldsmith, D.W. Henderson, T.A. Gosselin, D.E. King, J.J. Konrad, A. Sarkhel and K.J. Puttlitz: Interfacial reaction studies on lead (Pb)-free solder alloys. IEEE Trans-EPM 25, 155 (2002).

    CAS  Google Scholar 

  2. S.K. Kang, W.K. Choi, M.J. Yim and D.Y. Shih: Studies of the mechanical and electrical properties of lead-free solder joints. J. Electron. Mater. 31, 1292 (2002).

    Article  CAS  Google Scholar 

  3. Y.C. Sohn, J. Yu, S.K. Kang, D.Y. Shih and T.Y. Lee: Spalling of intermetallic compounds during the reaction between lead-free solders and electroless Ni-P metallization. J. Mater. Res. 19, 2428 (2004).

    Article  CAS  Google Scholar 

  4. M.N. Islam, Y.C. Chan, A. Sharif and M.O. Alam: Comparative study of the dissolution kinetics of electrolytic Ni and electroless Ni-P by the molten Sn3.5Ag0.5Cu solder alloy. Microelectron. Reliab. 43, 2031 (2003).

    Article  CAS  Google Scholar 

  5. M. He, W.H. Lau, G. Qi and Z. Chen: Intermetallic compound formation between Sn–3.5Ag solder and Ni-based metallization during liquid state reaction. Thin Solid Films 462–463, 376 (2004).

    Article  Google Scholar 

  6. M. He, Z. Chen and G. Qi: Solid state interfacial reaction of Sn–37Pb and Sn–3.5Ag solders with Ni–P under bump metallization. Acta Mater. 52, 2047 (2004).

    Article  CAS  Google Scholar 

  7. Y. Li: An experimental study on organic solderability preservative. In Proceedings of the IEEE/CPMT International Electronics Manufacturing Technology Symposium, New York, NY, 1997; p. 56.

    Google Scholar 

  8. C.Y. Liu, C. Chen, A.K. Mal and K.N. Tu: Direct correlation between mechanical failure and metallurgical reaction in flip chip solder joints. J. Appl. Phys. 85, 3882 (1999).

    Article  CAS  Google Scholar 

  9. Y.H. Liu, C.M. Chuang and K.L. Lin: Failure behavior upon shear test of 5Sn–95Pb solder bump after high temperature reliability test. J. Mater. Res. 19, 2471 (2004).

    Article  CAS  Google Scholar 

  10. S.T. Nurmi, J.J. Sundelin, E.O. Ristolainen and T. Lepistö: The influence of multiple reflow cycles on solder joint voids for lead-free PBGAs. Solder. Surf. Mater. Technol. 15, 31 (2003).

    Article  CAS  Google Scholar 

  11. D.R. Frear, S.N. Burchett, H.S. Morgan and J.H. Lau: The Mechanics of Solder Alloy Interconnects (Van Nostrand Reinhold, New York, 1994).

    Google Scholar 

  12. J.H. Westbrook and R.L. Fleischer Historical sketch, in Intermetallic Compounds (John Wiley & Sons Ltd., New York, 1967).

    Google Scholar 

  13. M.O. Alam, Y.C. Chan and K.N. Tu: Effect of reaction time and P content on mechanical strength of the interface formed between eutectic Sn-Ag solder and Au/electroless Ni(P)/Cu bond pad. J. Appl. Phys. 94, 4108 (2003).

    Article  CAS  Google Scholar 

  14. P.G. Harris and K.S. Chaggar: The role of intermetallic compounds in lead-free soldering. Solder. Surf. Mt. Tech. 10, 38 (1998).

    Article  CAS  Google Scholar 

  15. J.L. Marshall, J. Calderon, J. Sees, G. Lucey and J.S. Hwang: Composite solders. IEEE Trans-CHMT. 14, 698 (1991).

    CAS  Google Scholar 

  16. K. Mohankumar, A.A.O. Tay and V. Kripesh Nano-particle reinforced solders for fine pitch applications. Proceedings of the Electronics Packaging Technology Conference, New York, NY, 2004; p. 455.

    Google Scholar 

  17. M.O. Alam, Y.C. Chan and K.C. Hung: Reliability study of the electroless Ni-P layer against solder alloy. Microelectron. Reliab. 42, 1065 (2002).

    Article  Google Scholar 

  18. A.A. Liu, H.K. Kim, K.N. Tu and P.A. Totta: Spalling of Cu6Sn5 spheroids in the soldering reaction of eutectic SnPb on Cr/Cu/Au thin films. J. Appl. Phys. 80, 2774 (1996).

    Article  CAS  Google Scholar 

  19. H.K. Kim, H.K. Liou and K.N. Tu: Three-dimensional morphology of a very rough interface formed in the soldering reaction between eutectic SnPb and Cu. Appl. Phys. Lett. 66, 2337 (1995).

    Article  CAS  Google Scholar 

  20. H.K. Kim and K.N. Tu: Kinetic analysis of the soldering reaction between eutectic SnPb alloy and Cu accompanied by ripening. Phys. Rev. B 53, 16027 (1996).

    Article  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Yuseong-gu, Daejeon, 305-701, Korea

    Jung-Sub Lee, Kun-Mo Chu & Duk Young Jeon

Authors
  1. Jung-Sub Lee
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Kun-Mo Chu
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Duk Young Jeon
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Duk Young Jeon.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Lee, JS., Chu, KM. & Jeon, D.Y. Shear strength of Sn–3.5Ag solder bumps formed on Ni/Au and organic solderability preservative surface-finished bond pads after multiple reflow steps. Journal of Materials Research 20, 3088–3093 (2005). https://doi.org/10.1557/JMR.2005.0380

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1557/JMR.2005.0380

Search

Navigation