材料期刊网

Electromigration in the Ni/Sn-Zn/Cu solder interconnect was studied with an average current density of 3.51 x 10(4) A/cm(2) for 168.5 h at 150A degrees C. When the electrons flowed from the Ni side to the Cu side, uniform layers of Ni(5)Zn(21) and Cu(5)Zn(8) were formed at the Ni/Sn-Zn and Cu/Sn-Zn interfaces. However, upon reversing the current direction, where electron flow was from the Cu side to the Ni side, a thicker Cu(6)Sn(5) phase replaced the Ni(5)Zn(21) phase at the Ni/Sn-Zn interface, whereas at the Cu/Sn-Zn interface, a thicker beta-CuZn phase replaced the Cu(5)Zn(8) phase.