Zhou Hongliang, Chang Andong, Fan Junling, Cao Jun, Zhang Yingchong, An Bin, Xia Jie
School of Mechanical and Power Engineering, Henan Polytechnic University, Jiaozuo 454000, China.
School of Chemical and Environmental Engineering, Jiaozuo University, Jiaozuo 454000, China.
Micromachines (Basel). 2023 Aug 12;14(8):1587. doi: 10.3390/mi14081587.
Bond properties were performed on Ag-2.35Au-0.7Pd-0.2Pt-0.1Cu alloy wire with a diameter of 25 µm under different process parameters. The effects of electrical flaming off (EFO) current and EFO time on the deformability of the free air ball (FAB) were investigated using scanning electron microscopy (SEM), as well as the effects of ultrasonic power and bonding force on the bond characteristic. The experimental results show that FAB grows from a preheated tip to a small ball, a regular ball, and finally to a golf ball with increasing either the EFO current or the EFO time, and the FAB presents an optimal shape at 25 mA and 650 μs. Moreover, a nonlinear relationship between FAB diameter and EFO time is obtained at an EFO current of 25 mA, which could be expressed by a cubic equation. Further, at a constant bonding force, as the ultrasonic power increased, the mashed ball diameter grew larger and larger, the capillary hole imprint became more and more obvious, and the tail width also increased, and vice versa. The optimal ultrasonic power and bonding force are 70 mW and 45 gf for ball bonding and 90 mW and 75 gf for wedge bonding, respectively. Finally, for all the bonded wire samples prepared under optimal process parameters, no ball and wedge bond lifts happened after the destructive pull test, and full intermetallic compound coverage with perfect morphology occurred on the bond pad after the ball shear test, which meant that the bonded wire samples had high bond strength and hence improved the reliability of microelectronic products. It provided technical support for the reliability research of Pt-containing Ag-based bonding alloy wires.
在不同工艺参数下，对直径为25 µm的Ag-2.35Au-0.7Pd-0.2Pt-0.1Cu合金丝进行了键合性能测试。使用扫描电子显微镜（SEM）研究了电烧球（EFO）电流和EFO时间对自由空气球（FAB）可变形性的影响，以及超声功率和键合力对键合特性的影响。实验结果表明，随着EFO电流或EFO时间的增加，FAB从预热尖端生长为小球、规则球，最终变为高尔夫球，并且FAB在25 mA和650 μs时呈现出最佳形状。此外，在25 mA的EFO电流下，FAB直径与EFO时间之间存在非线性关系，该关系可用三次方程表示。进一步地，在恒定键合力下，随着超声功率的增加，压扁球直径越来越大，毛细管孔印记越来越明显，尾宽也增加，反之亦然。对于球形键合，最佳超声功率和键合力分别为70 mW和45 gf；对于楔形键合，最佳超声功率和键合力分别为90 mW和75 gf。最后，对于在最佳工艺参数下制备的所有键合丝样品，在破坏性拉力测试后未发生球键和楔形键抬起现象，并且在球剪切测试后，键合焊盘上出现了形态完美的完全金属间化合物覆盖，这意味着键合丝样品具有较高的键合强度，从而提高了微电子产品的可靠性。它为含铂银基键合合金丝的可靠性研究提供了技术支持。
