Summary: | Solder joint is important for providing mechanical support and functionality of electronic packaging. Established
solder joint should be able to withstand in device service operation and the environment without significant changes
in terms of their microstructural evolution and mechanical properties. This study investigates the effect of the coating
element (Sn and Ni) on the joining stability of Sn-0.3Ag-0.7Cu solder joint. The solder joints were exposed to different
aging test for 1000 h to observed microstructure and micromechanical properties changes. Microstructural observation
by means of intermetallic compound layer thickness due to the aging temperature effect. Joining stability by means
of micromechanical changes were studied using nanoindentation approach. It was found that the elastic behavior,
reduced modulus, and hardness of Sn-0.3Ag-0.7Cu solder joint has reduced due to aging test. However, the plastic
behavior of Sn-0.3Ag-0.7Cu solder joint has increased with the increase of the aging temperature. It is observed that
the Ni coating has a significant effect and a more stable solder joint achieved. This can be evidenced from small
changes in intermetallic compound layer thickness and micromechanical properties were achieved using Ni coating as
compared to Sn coating after subjected to the aging test for 1000 h.
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