A novel interface strengthening layer: Nanoscale AuCu super-structure formed during Au80Sn20/Cu rapid solidification soldering process

作者：Huang, Yufeng; Liu, Wensheng^*; Ma, Yunzhu^*; Tang, Siwei^*; Wang, Juan; Chen, Baishan

来源：Materials Characterization, 2018, 135: 214-220.

DOI：10.1016/j.matchar.2017.11.043

• Electronic materials
• Au80Sn20 solder
• Coherent interface
• AuCu super-structure
• Intermetallic alloys and compounds

Phase composition and orientation of intermetallic compounds layers determine the functional and mechanical properties of solder joints. In this paper, interfacial reaction and strengthening mechanism of Au80Sn20/Cu joint by rapid solidification reflow soldering were studied. The Au80Sn20/Cu solder joint by rapid solidification reflow soldering exhibit a superior shear property, and the shear strength reaches up to 90 MPa. It is found that a new nanoscale AuCu super-structure formed in the interfacial intermetallic compounds layer, which is coherent with the [001] Cu substrate. The orientation relationship of Cu matrix/interfacial intermetallic compounds is determined to be[001](Cu) || [001](AuCu) || [(2) over bar4 (2) over bar3]((Au),(Cu)5Sn) and (200)(Cu) || (200)(AuCu) || (10 (1) over bar0)((Au),(Cu5Sn). Nanoscale AuCu super-structure influences the interface slip direction and provides interface misfit dislocation, hinder the dislocation movement, lead to the interface strengthening effect. Our finding on nanoscale AuCu super-structure formed during Au80Sn20/Cu soldering process not only sheds light on future research direction but also provides practical guidance to the engineers in solder industry.

• 出版日期2018-1
• 单位中南大学; 粉末冶金国家重点实验室