Evolution of microstructure and mechanical properties of Cu/SAC305/Cu solder joints under the influence of low ultrasonic power
Evolution of microstructure and mechanical properties of Cu/SAC305/Cu solder joints under the influence of low ultrasonic power
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DOI：
10.1016/j.jallcom.2017.02.165
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发表时间：
2017-05
影响因子：
6.2
通讯作者：
A. Tan;A. Tan;F. Yusof
中科院分区：
文献类型：
--
作者：
A. Tan;A. Tan;F. Yusof
采用改进的超声波辅助回流焊技术，在常压下制备了Cu/SAC 305/Cu焊点。超声振动（USV）与低超声功率范围从10到30 W，而在这项研究中的影响下，这样的USV的焊点的微观结构和力学性能的演变进行了研究。结果表明，超声功率促进了焊点中共晶相的形成和β-Sn相的粗化。当超声处理时间延长时，β-Sn相由枝晶（10 W）转变为球状（20和30 W）。随着超声功率和超声时间的增加，钎料基体中β-Sn和共晶相的形态变化导致钎料基体硬度的变化和界面金属间化合物（IMC）的形成。总体而言，超声处理的样品的剪切强度随着超声功率的增加而增加，与USV时间无关。
Cu/SAC305/Cu solder joints were fabricated by a modified ultrasonic-assisted reflow soldering technique under ambient atmosphere. Ultrasonic vibration (USV) with low ultrasonic power ranging from 10 to 30 W was used while the evolution of microstructure and mechanical properties of the solder joints under the influence of such USV were investigated in this study. Results showed that ultrasonic power promoted the formation of eutectic phase and the coarsening of β-Sn phase in the solder matrix of the solder joints. When the samples were treated with longer USV time, the β-Sn phase changed from dendritic structure (10 W of USV) to globular structure (20 and 30 W of USV). The observed morphological change of β-Sn and eutectic phases in the solder matrix led to the variation in the solder matrix hardness and the formation of interfacial intermetallic compounds (IMCs) in the samples treated with USV at increasing ultrasonic power and time. Overall, the shear strength of the ultrasonic-treated samples increased with increasing ultrasonic power, regardless of the USV time.