Interfacial toughness evaluation of SAC305 solder bump with pendulum impact test

The high impact speeds (200, 1000 mm/s) in the pendulum test were conducted on the SAC305/ENIG joints aged at 150°C for 500 and 1000 h, respectively. The preliminary results exhibit that the peak force, pre-peak energy and total impact energy except post-energy of as-reflowed are larger than those of as-aged samples regardless of aging time. For the as-reflowed SAC305/ENIG joint (0.3 mm at diameter), the peak force is 2.592 N at the speed of the 1000 mm/s; the impact toughness is 0.168 mJ and the total impact energy is 0.345 mJ. Fracture mode also reveals the typical IMC fracture.