Microstructural evolution of 96.5Sn–3Ag–0.5Cu lead free solder reinforced with nickel-coated graphene reinforcements under large temperature gradient

Guang Chen; Li Liu; Vadim V. Silberschmidt; Changqing Liu; Fengshun Wu; Y. C. Chan

doi:10.1007/s10854-017-8489-7

Author(s)

Guang Chen
Li Liu
Vadim V. Silberschmidt
Changqing Liu
Fengshun Wu

Related Research Unit(s)

Department of Electrical Engineering

Detail(s)

Original language	English
Pages (from-to)	5253-5263
Journal / Publication	Journal of Materials Science: Materials in Electronics
Volume	29
Issue number	7
Online published	6 Jan 2018
Publication status	Published - Apr 2018

Link(s)

DOI	DOI https://doi.org/10.1007/s10854-017-8489-7 Final Published version
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Attachment(s)	Documents 21621299.pdf Final Published version, 3.04 MB, PDF Publisher's Copyright Statement This full text is made available under CC-BY 4.0. https://creativecommons.org/licenses/by/4.0/
Link to Scopus	https://www.scopus.com/record/display.uri?eid=2-s2.0-85040043293&origin=recordpage
Permanent Link	https://scholars.cityu.edu.hk/en/publications/publication(93d1bee5-e337-4b1e-9dd0-cb8e9e5c8326).html

Abstract

In this study, 96.5Sn–3Ag–0.5Cu (SAC305) lead-free composite solder containing graphene nanosheets (GNS) decorated with Ni nanoparticles (Ni-GNS) was prepared using a powder metallurgy method. A lab-made set-up and a corresponding Cu/solder/Cu sample design for assessing thermo-migration (TM) was established. The feasibility of this setup for TM stressing using an infrared thermal imaging method was verified; a temperature gradient in a solder joint was observed at 1240 K/cm. Microstructural evolution and diffusion of Cu in both plain and composite solder joints were then studied under TM stressing conditions. Compared to unreinforced SAC305 solder, the process of diffusion of Cu atoms in the composite solder joint was significantly reduced. The interfacial intermetallic compounds (IMCs) present in the composite solder joint also provide a more stable morphology after the TM test for 600 h. Furthermore, during the TM test, the Ni-GNS reinforcement affects the formation, migration and distribution of Ni–Cu–Sn and Cu–Sn IMCs by influencing the dissolution rate of Cu atoms.