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Download fileMicrostructural evolution of Cu–Sn–Ni compounds in full intermetallic micro-joint and in situ micro-bending test
journal contribution
posted on 2019-01-18, 13:25 authored by Liping Mo, Chaowei Guo, Zheng Zhou, Fengshun Wu, Changqing LiuChangqing LiuThis study focuses on the microstructural evolution process of Cu–Sn–Ni intermetallic compounds (IMCs) interlayer in the
micro-joints, formed from the initial Ni/Sn (1.5 µm)/Cu structure through transient liquid phase (TLP) soldering. Under the
bonding temperature of 240 °C, the micro-joints evolve into Ni/(Cu, Ni)6Sn5/(Cu, Ni)3Sn/Cu structure, where the interfacial
reactions on Cu/Sn and Sn/Ni are suppressed by the atoms diffusing from the opposite side. The thickness of (Cu, Ni)3Sn
layer on plated Cu layer still increases with the prolonged dwell time. When the bonding temperature was elevated to 290 °C,
the phase transformation of (Cu, Ni)6Sn5 into (Cu, Ni)3Sn has been accelerated, thus the majority of IMCs interlayer is
constituted with (Cu, Ni)3Sn. However, a small amount of Ni-rich (Cu, Ni)6Sn5 phases still remain near the Ni substrate and
some of them close to the center-line of IMCs interlayer. The state between (Cu, Ni)6Sn5 and the adjacent (Cu, Ni)3Sn tends
to reach equilibrium in Ni content based on the observation from Transmission Electron Microscope (TEM). In addition,
the Cu–Sn–Ni IMCs micro-cantilevers were fabricated from these micro-joints using Focus Ion Beam (FIB) for the in situ
micro-bending test, the results indicate a high ultimate tensile strength as well as the brittle fracture in the inter- and transgranular modes.
Funding
This work was supported by the National Nature Science Foundation of China [NSFC No. 61574068] and the Fundamental Research Funds for the Central Universities [No. 2016JCTD112].
History
School
- Mechanical, Electrical and Manufacturing Engineering
Published in
Journal of Materials Science: Materials in ElectronicsVolume
29Issue
14Pages
11920 - 11929Citation
MO, L. ... et al., 2018. Microstructural evolution of Cu–Sn–Ni compounds in full intermetallic micro-joint and in situ micro-bending test. Journal of Materials Science: Materials in Electronics, 29(14), pp. 11920 - 11929.Publisher
© Springer NatureVersion
- AM (Accepted Manuscript)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/Acceptance date
2018-05-12Publication date
2018-05-22Notes
This is a post-peer-review, pre-copyedit version of an article published in Journal of Materials Science: Materials in Electronics. The final authenticated version is available online at: https://doi.org/10.1007/s10854-018-9293-8ISSN
0957-4522eISSN
1573-482XPublisher version
Language
- en