银键合丝力学性能对键合质量的影响

Effect of the Mechanical Properties on the Bonding Quality of Ag Bonding Wires

通过调节微合金元素的含量获得3种具有不同力学性能的银键合丝。利用拉伸试验、键合试验、焊线挑断力、焊球推力测试等手段,研究了银键合丝力学性能对键合质量的影响。结果表明,在延伸率相同的条件下,随着微合金元素含量的降低,3种键合丝的断裂负荷降低,初始模量先减小后增大,键合后焊线挑断力和焊球推力均降低,电极金挤出率先减小后增大。银键合丝初始模量较低时在超声和压力的作用下易于变形,焊线内残余应力较低且第二焊点与引线框架结合较好,因此挑断测试时第二焊点与框架材料界面处不易发生脱离,有利于获得更高的键合成功率。

Three kinds of Ag bonding wires with different mechanical properties were obtained by adjusting the contents of micro alloying elements. The influence of the mechanical property of the Ag bonding wire on the bonding quality was studied on the basis of tensile test,bonding test,wire pulling force and ball shear force test,etc. The results show that the breaking loads of three kinds of Ag bonding wires decrease,the initial modulus first decreases then increases,the wire pulling force and ball shear force decrease,and the electrode gold extrusion rate first decreases then increases with the decrease of the micro alloying element contents in the condition of equal elongation. The Ag bonding wire with lower initial modulus was easily deformed under the act of ultrasound and stress,resulting in lower residual stress in the wire and better interfacial bonding between the second bond and the lead frame. During the pulling test,the second solder joint was difficult to detach from the interface of the frame material,and higher successful bonding rate was obtained.