Effects of trace amount praseodymium and neodymium on microstructure and mechanical properties of Sn–0.3Ag–0.7Cu–0.5Ga solder

  • Yilong Han
  • Songbai Xue
  • Jinlong Yang
  • Weimin Long
  • Qingke Zhang


The effects of trace mount of rare earth elements Pr and Nd addition on Sn–0.3Ag–0.7Cu–0.5Ga lead free solder were investigated by observation of microstructure and the morphology of interface layer, as well as the test of shearing strength of the solder joints. The results show that the microstructure of the solder matrix can be optimized by appropriate addition of Pr and Nd, but the scalloped and “region-like” compounds (IMCs) appear in the solder matrix with excessive Pr and Nd addition respectively which may result in the stress concentration and become the birthplace of the cracks. The behavior of absorption of rare earth elements can retard the interface reaction between solder and Cu substrate, refine the morphology of the interface layer. The shearing strength of the solder joints can be enhanced better with appropriate addition of Pr than Nd by improvement of nucleation rate and control of growth rate of the grains near the interface layer.


Shear Strength Solder Joint Interface Layer Solder Matrix Shear Strength Test 
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The Project was supported by the Key Laboratory of Advanced Welding Technology of Jiangsu Province, China (Foundation No. JSAWT-14-04). This work was also supported by the Fundamental Research Funds for the Central Universities and the Foundation of Graduate Innovation Center in NUAA (Foundation No. kfjj20150604) and this work was also supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).


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Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • Yilong Han
    • 1
  • Songbai Xue
    • 1
  • Jinlong Yang
    • 1
  • Weimin Long
    • 2
  • Qingke Zhang
    • 2
  1. 1.College of Materials Science and TechnologyNanjing University of Aeronautics and AstronauticsNanjingChina
  2. 2.State Key Laboratory of Advanced Brazing Filler Metals and TechnologyZhengzhou Research Institute of Mechanical EngineeringZhengzhouChina

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