Cu3Sn joint based on transient liquid phase bonding of Cu@Cu6Sn5 core-shell particles

Jintao Wang; Jianqiang Wang; Fangcheng Duan; Hongtao Chen

doi:10.1038/s41598-023-27870-3

Cu₃Sn joint based on transient liquid phase bonding of Cu@Cu₆Sn₅ core-shell particles

Sci Rep. 2023 Jan 12;13(1):668. doi: 10.1038/s41598-023-27870-3.

Authors

Jintao Wang^{1

2}, Jianqiang Wang^{3

4}, Fangcheng Duan^{3

4}, Hongtao Chen^{5

6}

Affiliations

¹ State Key Lab of Advanced Soldering and Joining, Harbin Institute of Technology, Harbin, 150001, China. jintaowcqu@foxmail.com.
² Sauvage Laboratory for Smart Materials, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China. jintaowcqu@foxmail.com.
³ State Key Lab of Advanced Soldering and Joining, Harbin Institute of Technology, Harbin, 150001, China.
⁴ Sauvage Laboratory for Smart Materials, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China.
⁵ State Key Lab of Advanced Soldering and Joining, Harbin Institute of Technology, Harbin, 150001, China. chenht@hit.edu.cn.
⁶ Sauvage Laboratory for Smart Materials, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China. chenht@hit.edu.cn.

Abstract

With the development of high-integration and high-power electronics, the lack of matching chip connecting materials that can withstand high temperatures has been a challenge. In this manuscript, a Cu@Cu₆Sn₅ core-shell bimetallic particles (approx. 1 μm in diameter) are successfully prepared and introduced as a new solder material for the packaging of power devices to obtain a Cu₃Sn all-IMC solder joint. The joint consisted mainly of equiaxed Cu₃Sn grains, and a small portion of columnar Cu₃Sn grains. In columnar-type growth, Sn is the dominant diffusing species, which comes from the depletion of Sn in Cu₆Sn₅. The depleted Cu₆Sn₅ is transformed into columnar Cu₃Sn. In equiaxed-type growth, Cu is the dominant diffusing species. Cu reacts with Cu₆Sn₅ to grow a Cu₃Sn layer. This conclusion was confirmed by the orientation relationship. The equiaxed Cu₃Sn grain nucleates at the Cu/Cu₃Sn interface have an orientation relationship with the Cu substrate. Columnar Cu₃Sn grains at the Cu₆Sn₅/Cu₃Sn interface have an orientation relationship with Cu₆Sn₅.