Journal of Failure Analysis and Prevention

, Volume 10, Issue 1, pp 50–55 | Cite as

Detrimental Effects of Excessive Gold Plating on Lead-Free Solder Joints

Technical Article---Peer-Reviewed
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Abstract

While most of the industries are striving very hard to produce totally lead-free electronic products, many concerns remain regarding lead-free solder joint reliability. One major concern is the robustness of gold metallization of the electronic components for lead-free soldering. Increasing gold content has been known to result in embrittlement and early failure in electronic assemblies. Therefore, information about the lead-free solder/gold metallization interdiffusion at high-temperature applications is very important for controlling the technological processes for the reliability of the electronic interconnects. The challenges of solder/gold metallization interdiffusion during high-temperature application/test are gold embrittlement, intermetallics growth, void formation, and also tin-whisker formation. This paper illustrates few case histories of such challenges. Importance of the thickness of the gold termination has been discussed and some parameters to optimizing the thickness of the gold termination have been suggested. Some remedial measures are suggested to control the lead-free solder/gold metallization diffusion in the electronics interconnects.

Keywords

Lead-free solders Gold embrittlement Metallization Tin whiskers Interdiffusion 

References

  1. 1.
    Darveaux, R., et al.: In: Lau, J. (ed.) Ball Grid Array Technology, chap. 13 (1995)Google Scholar
  2. 2.
    Zhong, C.H., et al.: Missing solder ball failure mechanism in plastic ball grid array packages, ECTC 200, pp. 151–159Google Scholar
  3. 3.
    Ferguson, M.E., et al.: Manufacturing concerns when soldering with gold plated component leads or circuit board pads. IEEE Trans. Comp. Packag. Manuf. Technol. C 20(3), 186–193 (1997)MathSciNetGoogle Scholar
  4. 4.
    Kramer, P.A., et al.: The effect of low Au concentration on the creep of eutectic Sn-Pb joints. Metall. Mater. Trans. A 25A, 1249–1255 (1994)CrossRefADSGoogle Scholar
  5. 5.
    Kim, P.G., et al.: Fast soldering reactions on Au foils. Materials Research Society, Symposium Proceedings, vol. 445, pp. 131–136 (1997)Google Scholar
  6. 6.
    Mei, Z., et al.: Brittle interfacial fracture of PBGA packages soldered on electroless Ni/Immersion gold, Hewlett-Packard CompanyGoogle Scholar
  7. 7.
    Dunford, S.O., et al.: Microstructural evolution and damage mechanisms in Pb-free solder joints during extended −40 to 125°C thermal cycles, IPC 2002, New Orleans, LA, Nov 2–3 (2002)Google Scholar
  8. 8.
    Meilunas, M., et al.: Reliability and failure analysis of lead-free solder joints, IPC 2002, New Orleans, LA, Nov 2–3 (2002)Google Scholar
  9. 9.
    Zeng, K., et al.: Formation of intermetallic compounds in solder joints and its effects on joint reliability, Helsinki University of Technology, Report Series HUT-EPT-2 2000, ISBN 951-22-4980-4Google Scholar
  10. 10.
    Dunford, S., et al.: Metallurgical and reliability aspects of lead-free mixed technology electronic assembly for mobile communication products, IPC Works 2000, Miami, FL, Sept 9–14 (2000)Google Scholar
  11. 11.
    Zheng, Y., et al.: Intermetallic growth on PWBs soldered with Sn3.8Ag0.7Cu. Proceedings of ECTC 2002, San Diego, CA, May 28–31 (2002)Google Scholar
  12. 12.
    Zeng, K., et al.: Six cases of reliability study of Pb-free solder joints in electronic packaging technology. Mater. Sci. Eng. Rep. (Invited), 38(2), 55–105 (2002)CrossRefGoogle Scholar
  13. 13.
    Brusse, J.: Tin whisker observations on pure tin-plated ceramic chip capacitors. AESFSUR/FIN Proceedings, pp. 45–61, June 24–27 (2002)Google Scholar
  14. 14.
    NASA Goddard Space Flight Center, Basic Info/FAQ. http://nepp.nasa.gov/whisker/background/
  15. 15.
    Zhang, Y., Xu, C., Abys, J., Vysotskaya, A.: Understanding whisker phenomenon, whisker index and tin/copper, tin/nickel interface, IPC, SMEMA Council APEX (2002)Google Scholar
  16. 16.
    Kadeshch, J., Brusse, J.: The continuing dangers of tin whiskers and attempt to control them with conformal coating. EEE Links, 1(2), July (2001)Google Scholar

Copyright information

© ASM International 2009

Authors and Affiliations

  1. 1.Failure Analysis and Materials Characterization LaboratorySchlumberger Technology CenterSugar LandUSA

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