Electromigration behavior of the Cu/Au/SnAgCu/Cu solder combination

Abstract

The electromigration behavior of the Cu/Au/SnAgCu/Cu combination was investigated under 103 A/cm2 of current stressing at ambient temperature. The Au layer, when it acts as a cathode, was consumed continuously, and no significant compound was found at the interface. Meanwhile, Cu6Sn5 was formed at the anodic Cu layer, and the thickness of the compound increased with increasing time. The Au atoms were found to be trapped in Cu6Sn5 within the solder matrix. The AuSn4 compound precipitated while attaching to Cu6Sn5 at the Cu6Sn5/solder interface. The thermomigration effect was found to be insignificant in this work as no obvious reaction occurred at the cathode/anode sides or in the solder matrix without current stressing.

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References

  1. 1

    Y.H. Lin, Y.C. Hu, C.M. Tsai, C.R. Kao, K.N. Tu: In situ observation of the void formation-and-propagation mechanism in solder joints under current-stressing. Acta Mater. 53, 2029 2005

    CAS  Article  Google Scholar 

  2. 2

    L. Zhang, S. Ou, J. Huang, K.N. Tu, S. Gee, L. Nguyen: Effect of current crowding on void propagation at the interface between intermetallic compound and solder in flip chip solder joints. Appl. Phys. Lett. 88, 012106 2006

    Article  Google Scholar 

  3. 3

    Y.W. Chang, S.W. Liang, C. Chen: Study of void formation due to electromigration in flip-chip solder joints using Kelvin bump probes. Appl. Phys. Lett. 89, 032103 2006

    Article  Google Scholar 

  4. 4

    W.J. Choi, E.C.C. Yeh, K.N. Tu: Mean-time-to-failure study of flip chip solder joints on Cu/Ni(V)/Al thin-film under-bump-metallization. J. Appl. Phys. 94, 5665 2003

    CAS  Article  Google Scholar 

  5. 5

    T.L. Shao, K.C. Lin, C. Chen: Electromigration studies of flip chip Sn95/Sb5 solder bumps on Cr/Cr–Cu/Cu under-bump metallization. J. Electron. Mater. 32, 1278 2003

    CAS  Article  Google Scholar 

  6. 6

    M.O. Alam, B.Y. Wu, Y.C. Chan, K.N. Tu: High electric current density-induced interfacial reactions in micro ball grid array (μBGA) solder joints. Acta Mater. 54, 613 2006

    CAS  Article  Google Scholar 

  7. 7

    C.Y. Liu, C. Chen, K.N. Tu: Electromigration in Sn–Pb solder strips as a function of alloy composition. J. Appl. Phys. 88, 5703 2000

    CAS  Article  Google Scholar 

  8. 8

    T.Y. Lee, K.N. Tu, S.M. Kuo, D.R. Frear: Electromigration of eutectic SnPb solder interconnects for flip chip technology. J. Appl. Phys. 89, 3189 2001

    CAS  Article  Google Scholar 

  9. 9

    T.Y. Lee, K.N. Tu, D.R. Frear: Electromigration of eutectic SnPb and SnAg3.8Cu0.7 flip chip solder bumps and under-bump metallization. J. Appl. Phys. 90, 4502 2001

    CAS  Article  Google Scholar 

  10. 10

    Y.T. Yeh, C.K. Chou, Y.C. Hsu, C. Chen, K.N. Tu: Threshold-current density of electromigration in eutectic SnPb solder. Appl. Phys. Lett. 86, 203504 2005

    Article  Google Scholar 

  11. 11

    Y.H. Liu, K.L. Lin: Damages and microstructural variation of high-lead and eutectic SnPb composite flip chip solder bumps induced by electromigration. J. Mater. Res. 20, 2184 2005

    CAS  Article  Google Scholar 

  12. 12

    J.W. Nah, J.H. Kim, H.M. Lee, K.W. Paik: Electromigration in flip chip solder bump of 97Pb–3Sn/37Pb–63Sn combination structure. Acta Mater. 52, 129 2004

    CAS  Article  Google Scholar 

  13. 13

    A.T. Huang, K.N. Tu, Y.S. Lai: Effect of the combination of electromigration and thermomigration on phase migration and partial melting in flip chip composite SnPb solder joints. J. Appl. Phys. 100, 033512 2006

    Article  Google Scholar 

  14. 14

    J.W. Nah, K.W. Paik, J.O. Suh, K.N. Tu: Mechanism of electromigration-induced failure in the 97Pb–3Sn and 37Pb–63Sn composite solder joints. J. Appl. Phys. 94, 7560 2003

    CAS  Article  Google Scholar 

  15. 15

    Y.C. Hsu, T.L. Shao, C.J. Yang, C. Chen: Electromigration study in SnAg3.8Cu0.7 solder joints on Ti/Cr–Cu/Cu under-bump metallization. J. Electron. Mater. 32, 1222 2003

    CAS  Article  Google Scholar 

  16. 16

    T.L. Shao, Y.H. Chen, S.H. Chiu, C. Chen: Electromigration failure mechanisms for SnAg3.5 solder bumps on Ti/Cr–Cu/Cu and Ni(P)/Au metallization pads. J. Appl. Phys. 96, 4518 2004

    CAS  Article  Google Scholar 

  17. 17

    Y.C. Hsu, C.K. Chou, P.C. Liu, C. Chen, D.J. Yao, T. Chou, K.N. Tu: Electromigration in Pb-free SnAg3.8Cu0.7 solder stripes. J. Appl. Phys. 98, 033523 2005

    Article  Google Scholar 

  18. 18

    K.N. Chiang, C.C. Lee, C.C. Lee, K.M. Chen: Current crowding-induced electromigration in SnAg3.0Cu0.5 microbumps. Appl. Phys. Lett. 88, 072102 2006

    Article  Google Scholar 

  19. 19

    H. Ye, C. Basaran, D. Hopkins: Thermomigration in Pb–Sn solder joints under Joule heating during electric current stressing. Appl. Phys. Lett. 82, 1045 2003

    CAS  Article  Google Scholar 

  20. 20

    S.H. Chiu, T.L. Shao, C. Chen, D.J. Yao, C.Y. Hsu: Infrared microscopy of hot spots induced by Joule heating in flip-chip SnAg solder joints under accelerated electromigration. Appl. Phys. Lett. 88, 022110 2006

    Article  Google Scholar 

  21. 21

    A.T. Huang, A.M. Gusak, K.N. Tu, Y.S. Lai: Thermomigration in SnPb composite flip chip solder joints. Appl. Phys. Lett. 88, 141911 2006

    Article  Google Scholar 

  22. 22

    F. Zhang, M. Li, C.C. Chum, C.H. Tung: Effects of substrate metallizations on solder/underbump metallization interfacial reactions in flip-chip packages during thermal aging. J. Mater. Res. 18, 1333 2003

    CAS  Article  Google Scholar 

  23. 23

    P.C. Shih, K.L. Lin: Interfacial bonding behavior with introduction of Sn–Zn–Bi paste to Sn–Ag–Cu ball grid array package during multiple reflows. J. Mater. Res. 20, 219 2005

    CAS  Article  Google Scholar 

  24. 24

    P.C. Shih, K.L. Lin: Effect of microstructural evolution on electrical property of the Sn–Ag–Cu solder balls joined with Sn–Zn–Bi paste. J. Mater. Res. 20, 2854 2005

    CAS  Article  Google Scholar 

  25. 25

    F. Ren, J.W. Nah, K.N. Tu, B. Xiong, L. Xu, J.H.L. Pang: Electromigration induced ductile-to-brittle transition in lead-free solder joints. Appl. Phys. Lett. 89, 141914 2006

    Article  Google Scholar 

  26. 26

    L. Zhang, Z.G. Wang, J.K. Shang: Current-induced weakening of Sn3.5Ag0.7Cu Pb-free solder joints. Scripta Mater. 56, 381 2007

    CAS  Article  Google Scholar 

  27. 27

    J.W. Nah, F. Ren, K.W. Paik, K.N. Tu: Effect of electromigration on mechanical shear behavior of flip chip solder joints. J. Mater. Res. 21, 698 2006

    CAS  Article  Google Scholar 

  28. 28

    B.F. Dyson, T.R. Anthony, D. Turnbull: Interstitial diffusion of copper in tin. J. Appl. Phys. 38, 3408 1967

    CAS  Article  Google Scholar 

  29. 29

    Z. Mei, A.J. Sunwoo, J.W. Morris: Analysis of low-temperature intermetallic growth in copper–tin diffusion couples. Metall. Trans. A 23, 857 1992

    Article  Google Scholar 

  30. 30

    B.F. Dyson: Diffusion of gold and silver in tin single crystals. J. Appl. Phys. 37, 2375 1966

    CAS  Article  Google Scholar 

  31. 31

    H.B. Huntington: Electromigration in metals in Diffusion in Solids: Recent Developments, edited by A.S. Nowick and J.J. Burton (Academic Press, New York, 1975), p. 303.

  32. 32

    T.B. Massalski: Binary Alloy Phase Diagrams ASM International Materials Park, OH 1986 315

    Google Scholar 

  33. 33

    C.W. Chang, Q.P. Lee, C.E. Ho, C.R. Kao: Cross-interaction between Au and Cu in Au/Sn/Cu ternary diffusion couples. J. Electron. Mater. 35, 366 2006

    CAS  Article  Google Scholar 

  34. 34

    S.W. Chen, Y.W. Yen: Interfacial reactions in the Sn–Ag/Au couples. J. Electron. Mater. 30, 1133 2001

    CAS  Article  Google Scholar 

Download references

Acknowledgment

The authors are grateful for the support of this research by the National Science Council, Republic of China, under NSC 94-2216-E-006-014.

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Correspondence to Tsung-Chieh Chiu.

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Chiu, TC., Lin, KL. Electromigration behavior of the Cu/Au/SnAgCu/Cu solder combination. Journal of Materials Research 23, 264–273 (2008). https://doi.org/10.1557/JMR.2008.0036

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