Advertisement

The Effect of Thermal Ageing on Solder/Substrate Interfacial Microstructures During Reflow of Sn–37Pb and Sn–3Ag–0.5Cu

  • SatyanarayanEmail author
  • M. C. Kumarswamy
  • K. N. Prabhu
Technical Paper
  • 16 Downloads

Abstract

In the current study, the influence of thermal ageing on evolution of microstructures in the interfacial region between solders (Sn–37Pb, Sn–3.5Ag–0.5Cu) and copper substrates was investigated. Pb-containing and Pb-free solders were reflowed on Cu substrates at 230 °C for 15 min and were isothermally aged at 100 °C for 24 h. As-reflowed Sn–Pb solder/Cu substrate interfacial region exhibited continuous and layered type of IMC at the interface, and this IMC morphology changed to scallop type with isothermal ageing. SAC solder/Cu as-reflowed samples showed continuous and needle-shaped Cu6Sn5 and Ag3Sn IMCs at the interface. However, in an isothermally aged condition, plate-shaped Cu6Sn5 and flower-shaped Ag3Sn IMCs were found inside the solder matrix. Scanning electron microscopic (SEM) study showed that the thickness of Cu6Sn5 IMC was higher in reflowed Sn–Pb/Cu region than in SAC/Cu region.

Keywords

Solder joint Reflow Microstructures IMC layer Isothermal ageing 

Notes

Acknowledgements

Authors thank former students Mr. Ammer Bilal, Mr. Bharath M M, Mr. Syed Dawood and Mr. Mohammed Sohail of AIET for conducting experiments.

Compliance with Ethical Standards

Conflict of interest

The author(s) declare that they have no conflict of interest.

References

  1. 1.
    Hwang J S, Implementing Lead-Free Electronics, McGraw-Hill, NewYork (2005) p 1.Google Scholar
  2. 2.
    Kumar G, and Prabhu K N, J ASTM Int 7 (2010) 1.CrossRefGoogle Scholar
  3. 3.
    Satyanarayan, and Prabhu K N, Adv Colloid Interface Sci 166 (2011) 87.Google Scholar
  4. 4.
    Suh J O, Tu K N, and Tamura N, J Appl Phys 6 (2007).Google Scholar
  5. 5.
    Anupam C, Microstructural Changes Under Isothermal Ageing and Their Influence on Thermal Fatigue Reliability for Tin-Lead and Lead-Free Solder Joints, Including Microstructural Changes Under Isothermal Ageing in Mixed Solder Joints, Ph D Thesis, University of Maryland (2007).Google Scholar
  6. 6.
    Mrunali S, and Prabhu K N, SMTA J 28 (2015) 36.Google Scholar
  7. 7.
    Rui Z X, Fu Y Z, Xin Z H, Kun Z L, and Qiang L J, Chin Sci Bull 55 (2010) 797.CrossRefGoogle Scholar
  8. 8.
    Islam M N, Chan Y C, Rizvi M J, and Jillek W, J Alloys Compd (2005) 136.Google Scholar
  9. 9.
    Hassan N A, Study of Interfacial Reaction During Reflow Soldering of SnAgCu Lead-Free Solders on Bare Copper and Immersion Silver Surface Finishes. Ph D diss., Universiti Teknologi Malaysia (2009).Google Scholar
  10. 10.
    Sharif A, and Chan Y C, Mater Sci Eng B 106 (2004) 126.Google Scholar
  11. 11.
    Satyanarayan and Prabhu K N, J Mater Sci: Mater Electron 23 (2012) 1664.Google Scholar

Copyright information

© The Indian Institute of Metals - IIM 2019

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringAlva’s Institute of Engineering and TechnologyMoodabidriIndia
  2. 2.Department of Metallurgical and Materials EngineeringNational Institute of Technology Karnataka (NITK)MangaloreIndia

Personalised recommendations