A comparative study of Sn3.5Ag and Sn3.8Ag0.7Cu for BGA spheres on Ni/Au finish

Poh Leng Eu, Min Ding, Huey Jiun Hoh, Joachim Rayos, Peng Su, Wayne Lindsay, Sheila Chopin, Ibrahim Ahmad

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Citations (Scopus)

Abstract

A comparative study was conducted with Sn3.5%Ag and Sn3.8%Ag0.7%Cu solder balls on Ball Grid Array (BGA) packages with Ni/Au pad finishing. The study was carried out in different levels. At individual solder joint level, Sn3.5Ag showed no intermetallic brittle failure in cold ball pull test under any stress condition. In contrast, 70-100% of the failure mode of SAC387 was brittle failure. At package level, Sn3.5Ag survived 8-10x more drop cycles than SAC387 in tray drop and packing drop tests. These results indicate that the mechanical strength of Sn3.5Ag on Ni/Au pad is considerably stronger than that of SAC387. The difference in mechanical strength between the two alloys was correlated to their microstructures. At the same time, board level solder joint reliability tests such as thermal cycling and mechanical bend test were carried out. Sn3.5Ag showed similar performance as SAC387. The reason for the similarity was also explained by examining the microstructure change that occurred during board mounting process.

Original languageEnglish
Title of host publicationProceedings - 57th Electronic Components and Technology Conference 2007, ECTC '07
Pages1819-1824
Number of pages6
DOIs
Publication statusPublished - 22 Oct 2007
Event57th Electronic Components and Technology Conference 2007, ECTC '07 - Sparks, NV, United States
Duration: 29 May 200701 Jun 2007

Publication series

NameProceedings - Electronic Components and Technology Conference
ISSN (Print)0569-5503

Other

Other57th Electronic Components and Technology Conference 2007, ECTC '07
CountryUnited States
CitySparks, NV
Period29/05/0701/06/07

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All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

Cite this

Eu, P. L., Ding, M., Hoh, H. J., Rayos, J., Su, P., Lindsay, W., ... Ahmad, I. (2007). A comparative study of Sn3.5Ag and Sn3.8Ag0.7Cu for BGA spheres on Ni/Au finish. In Proceedings - 57th Electronic Components and Technology Conference 2007, ECTC '07 (pp. 1819-1824). [4250130] (Proceedings - Electronic Components and Technology Conference). https://doi.org/10.1109/ECTC.2007.374044