The scaling down of microelectronic circuits (ITRS Roadmap) and increasing functionality inevitably leads to smaller bond pads, smaller pitches and smaller diameters for the solder flip chip interconnections. This not only compromises the mechanical integrity of the joint, a smaller contact pad will also lead to an increased current density enhancing the risk for electromigration. This work provides some guidelines to perform solder bump electromigration testing. The experimental settings are shown to have a large effect on the failure modes and according failure analysis. A test case comparing the electromigration behaviour of two different under bump metallurgy–solder interfaces, being Cu–Sn and Cu/Ni/Au–Sn, is given. A special test structure that allows the separate measurement of the anodic and cathodic bump interface is introduced.


Solder Joint Joule Heating Under Bump Metallization Flip Chip Solder Interconnection 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. 1.
    ITRS RoadmapGoogle Scholar
  2. 2.
    Ohring M Reliability and failure of electronic circuitsGoogle Scholar
  3. 3.
    Ding M, Wang G, Chao B, Ho PS (2005) A study of electro-migration failure in Pb-free solder joints. In: Proceedings IEEE 43rd annual international reliability physics symposium, pp 518–523Google Scholar
  4. 4.
    Choi WJ, Yeh ECC, Tu KN (2001) Electro-migration in flip chip solder bump on Cu/Ni(V)/Al thin film UBM. In: Proceedings of ECTC, pp 1201–1205Google Scholar
  5. 5.
    Gan H, Tu KN (2002) Effect of electro-migration on intermetallic compound formation in Pb-free solder–Cu interfaces. In: Proceedings ECTC, pp 1206–1212Google Scholar
  6. 6.
    Chae SH, Chao B, Zhang X, Im J, Ho PS (2007) Investigation of intermetallic compound growth enhanced by electromigration in Pb-free solder joints. In: Proceedings ECTC, pp 1442–1449Google Scholar
  7. 7.
    Lee TY, Tu KN, Frear DM (2001) Electromigration of eutectic SnPb and SnAg3.8Cu0.7 flip chip solder bumps and under-bump metallization. J Appl Phys 90:3189–3193CrossRefGoogle Scholar
  8. 8.
    Ebersberger B, Bauer R, Alexa L (2004) Qualification of SnAg solder bumps for Pb-free flip chip applications. In: Proceedings ECTC, pp 683–691Google Scholar
  9. 9.
    Lin JK, Wang JW, White J (2003) Characterization of solder joint electro-migration for flip chip technology. In: Proceedings ECTC, pp 816–821Google Scholar
  10. 10.
    Labie R, Webers T, Swinnen B, Beyne E (2005) Electro-migration behavior of Pb-free flip chip bumps. In: Proceedings EMPCGoogle Scholar
  11. 11.
    Chae SY, Zhang X, Lu KH, Cha HL, Ho PS, Ding M, Su P, Uehling T, Ramanathan LN (2007) Electromigration statistics and damage evolution for Pb-free solder joints with Cu and Ni UBM in plastic flip chip packages. J Mater Electron 18:247–258CrossRefGoogle Scholar
  12. 12.
    Kwon YM, Paik KW (2007) Electromigration of Pb-free solder flip chip using electroless Ni-P/Au. In: Proceedings of ECTC, pp 1472–1476Google Scholar
  13. 13.
    Black JR (1967) Current limitations of thin film conductors. In: Presented at 20th annual international reliability physics symposiumGoogle Scholar
  14. 14.
    Loyd JR, Clemens J, Snede R (1999) Copper metallization reliability. Microelectron Reliab 39:1595–1602CrossRefGoogle Scholar
  15. 15.
    Dunford S, Primavera A, Meilunas M (2002) Microstructural evolution and damage mechanisms in Pb-free solder joints during extended −40 to 125°C thermal cycles. In: Proceedings IPCGoogle Scholar
  16. 16.
    Pang JHL, Xiong BS, Low TH (2004) Low cycle fatigue study of Pb-free 99.3Sn–0.7Cu alloy. Int J Fatigue 26Google Scholar
  17. 17.
    Laurila T, Vuorinen V, Kivilahti JK (2005) Interfacial reactions between lead-free solders and common base materials. Mater Sci Eng R 49:1–6CrossRefGoogle Scholar
  18. 18.
    Chromik R (2003) Nano-indentation measurements on Cu–Sn and Ag–Sn intermetallics formed in Pb-free solder joints. J Mater Res 9:2251–2263CrossRefGoogle Scholar
  19. 19.
    Labie R, Webers T, Beyne E, Mertens R, Van Humbeeck J (2006) A modified electro-migration test structure for flip chip interconnections. IEEE Trans on CPMT 29:508–511Google Scholar
  20. 20.
    Horner V, Balkan H (2001) Reliability manual, report from FlipChip technologies.
  21. 21.
    Labie R, Ruythooren W, Van Humbeeck J (2007) Solid state diffusion of Cu–Sn and Ni–Sn diffusion couples with flip chip scale dimensions. Intermetallics 15:396–403CrossRefGoogle Scholar

Copyright information

© Springer-Verlag London Limited 2011

Authors and Affiliations

  1. 1.IMECLeuvenBelgium

Personalised recommendations