Journal of Materials Science

, Volume 42, Issue 13, pp 5239–5247 | Cite as

Multiple reflow study of ball grid array (BGA) solder joints on Au/Ni metallization

  • W. H. Zhong
  • Y. C. Chan
  • B. Y. Wu
  • M. O. Alam
  • J. F. Guan


This paper evaluates the shearing behavior of ball grid array (BGA) solder joints on Au/Ni/Cu pads of FR4 substrates after multiple reflow soldering. A new Pb-free solder, Sn–3Ag–0.5Cu–8In (SACI), has been compared with Sn–3Ag–0.5Cu (SAC) and Sn–37Pb (SP) solders, in terms of fracture surfaces, shearing forces and microstructures. Three failure modes, ball cut, a combination of solder shear and solder/pad bond separation, and pad lift, are assessed for the different solders and reflow cycles. It is found that the shearing forces of the SP and SAC solder joints tend to increase slightly with an increase in the number of reflow cycles due to diffusion-induced solid solution strengthening of the bulk solder and augmentation of the shearing area. However, the shearing forces of the SACI solder joints decrease slightly after four cycles of reflow, which is ascribed to the thermal degradation of both the solder/intermetallic compound (IMC) and IMC/Ni interfaces. The SACI solder joints yield the highest strengths, whereas the SP solder joints give the smallest values, irrespective of the number of reflow cycles. Thickening of the interfacial IMC layer and coarsening of the dispersing IMC particles within the bulk solders were also observed. Nevertheless, the variation of shearing forces and IMC thickness with different numbers of reflow cycles was not so significant since the Ni under layer acted as an effective diffusion barrier. In addition, the initially-formed IMC layer retarded the further extensive dissolution of the pad material and its interaction with the solder.


  1. 1.
    Richards BP, Levoguer CL, Hunt CP, Nimmo K, Peters S, Cusack P (1999) An analysis of the current status of lead-free soldering, (NPL, ITRI and DTI joint report about Pb-free soldering, Jan.).
  2. 2.
    Suganuma K (2003) Lead-free soldering in electronics: science, technology and environmental impact. Marcel Dekker, New YorkGoogle Scholar
  3. 3.
    Hwang JS (2001) Environment-friendly electronics. lead-free technology. Electrochemical Publications, New York, pp 277Google Scholar
  4. 4.
    Sattiraju SV, Dang B, Johnson RW, Li YL, Smith JS, Bozack MJ (2002) IEEE Trans Compon Packag Manuf Technol Part C Manuf 25:168Google Scholar
  5. 5.
    Connell JO (2005) Study and recommendations into using lead free printed circuit board finishes at manufacturing in circuit test stage (Agilent Technologies white paper).–1558EN.pdf
  6. 6.
    Toleno B (2003) PCB surface finish options for lead-free manufacturing, EMS 5.
  7. 7.
    Li M, Zhang F, Chen WT, Zeng K, Tu KN, Balkan H, Elenius P (2002) J Mater Res 17:1612Google Scholar
  8. 8.
    Alam MO, Chan YC, Tu KN (2004) J Mater Res 19:1303CrossRefGoogle Scholar
  9. 9.
    Huang XJ, Lee SWR, Yan CC (2002) In: Electronic components and technology conference, proceedings of the 52nd ECTC on 28–31 May, California, USA, pp 968Google Scholar
  10. 10.
    Chong V, Lee TK, Lim CT, Gunawan DK (2004) In: Electronics packaging technology conference, proceedings of 6th EPTC on 8–10 December, Singapore, pp 735Google Scholar
  11. 11.
    Yoon W, Kim SW, Jung SB (2005) J Alloys Compd 391:82CrossRefGoogle Scholar
  12. 12.
    Aderspm IE, Harringa JL (2004) J Electr Mater 33:1485CrossRefGoogle Scholar
  13. 13.
    Erich R, Richard JC, Wenger GM, Primavera A (1999) In: Proceedings of the 24th IEEE/CPMT international electronics manufacturing symposium on 18–19 October, Austin, TX, USA, pp 16Google Scholar
  14. 14.
    Lim ACP, Kheng LT, Alamsjah A (2003) In: Happy, electronics packaging technology conference, proceedings of 5th on 10–12 December, Pan Pacific Hotel, Singapore, pp 563Google Scholar
  15. 15.
    Fan JW, Kou CT, Yip MC (2003) In: Electronics packaging technology conference, proceedings of 5th on 10–12 December, Pan Pacific Hotel, Singapore, pp 712Google Scholar
  16. 16.
    Anand A, Mui YC, Weidier J, Diaz N (2004) Electronics packaging technology conference, proceedings of 6th on 8–10 December, Pan Pacific Hotel, Singapore, pp 335Google Scholar
  17. 17.
    Roger J, Kwong A (2001) Dealing with the “Black Pad Defect”—a failure analyst perspective, Solectron Corporation Milipitas, CA 95035.
  18. 18.
    Siewert T, Liu S, Smith DR, Madeni JC (2002) Database for solder properties with emphasis on new lead-free solders (report on properties of lead-free solders, release 4.0, National Institute of Standards and Technology & Colorado School of Mines)Google Scholar
  19. 19.
    Kim PG, Tu KN (1998) Mater Chem Phys 53:165CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • W. H. Zhong
    • 1
  • Y. C. Chan
    • 1
  • B. Y. Wu
    • 1
  • M. O. Alam
    • 1
  • J. F. Guan
    • 2
  1. 1.Department of Electronic EngineeringCity University of Hong KongHong KongP. R. China
  2. 2.Department of Mineral ProcessingWuhan University of Science and TechnologyWuhanP. R. China

Personalised recommendations