Impact of addition of Sn on resistivity and solderability of Zn4Al3Cu solder

The resistivity and solder abilities of Zn4Al3CuxSn solder alloy were investigated by adding Sn(0 - 15%) into Zn4Al3Cu alloy through alloying principle. Results show that the resistivity of the Zn4Al3CuxSn solders is reduced with the increasing of the addition of Sn.The resistivity of the Zn4Al3Cu15Sn solder is 7.9×10^{- 7} Ω·m which is approximately 47.0% lower than that of the matrix solder.When the content of Sn is lower than 10%,the spreading area of the Zn4Al3CuxSn solder alloy is increased linearly.The spreading area of Zn4Al3Cu10Sn reaches to the maximum value of 98.3 mm², which is about 59.1% larger than that of the matrix solder.It is mainly related to the formation of the new SnZn eutectic phase and the metal intermetallic compounds between the solder and the substrate.Therefore,for the consideration of resistivity and spreading property of the novel solders,the proper addition of Sn is about 10%.