J. Mater. Sci. Technol. ›› 2013, Vol. 29 ›› Issue (5): 471-479.DOI: 10.1016/j.jmst.2013.01.012

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Shear Deformation Behaviors of Sn3.5Ag Lead-free Solder Samples

Jing Han1), Hongtao Chen1), Mingyu Li1,2), Chunqing Wang2)   

  1. 1) Department of Materials Science and Engineering, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, China
    2) State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin 150001, China
  • Received:2012-01-01 Revised:2012-07-30 Online:2013-05-30 Published:2013-05-17
  • Contact: M. Li
  • Supported by:

    National Natural Science Foundation of China under Grant No. 50905042, the Shenzhen Special Funds for Overseas High-level Talents (No. KQC201109020053A), Shenzhen Technological Innovation Project (No. CXZZ20120829103358067) and the Shenzhen Special Funds for Strategic Emerging Industries (No. JCYJ20120613140542764).

Abstract:

In this study, shear tests have been performed on the as-reflowed Sn3.5Ag solder bumps and joints to investigate the deformation behavior of Sn3.5Ag lead-free solder samples. Scanning electron microscopy (SEM) was employed to characterize the microstructures of the samples and orientation imaging microscopy (OIM) with electron backscattered diffraction (EBSD) in SEM was used to obtain crystallographic orientation of grains to provide a detailed characterization of the deformation behavior in Sn3.5Ag solder samples after shear tests. The deformation behavior in solder samples under shear stress was discussed. The experimental results suggest that the dynamic recrystallization could occur under shear stress at room temperature and recrystallized grains should evolve from subgrains by rotation. Compared with that of non-recrystallized and as-reflowed microstructures, the microhardness of the recrystallized microstructure decreased after shear tests.

Key words: Shear test, Deformation behavior, Lead-free solder, Electron backscattered diffraction, Dynamic recrystallization, Microhardness