Reliability study of industry Sn3.0Ag0.5Cu/Cu lead-free soldered joints in electronic packaging

The wettability of Sn3.0Ag0.5Cu on copper substrate with different reflow temperature was studied. The growth mechanism of intermetallic compound (IMC) and mechanical properties were also investigated under isothermal aging condition at 125, 150 and 175 °C with different aging time. The results showed that, with the reflow temperature increasing, the spreading area of Sn3.0Ag0.5Cu lead-free solder increased. The morphology of IMC formed at Sn3.0Ag0.5Cu/Cu interface was gradually changed from scallop-type to planar-type, and the thickness of IMC was increased with the aging temperature and aging time. Meanwhile, the IMC growth rate increased with aging temperature but decreased with aging time. In addition, the mechanical properties of solder joints with different isothermal aging decreased with increasing aging time. In the initial stage of isothermal aging, the mechanical properties of solder joints decreased rapidly, then the rate of decline became stabilized.