Influences of silicon carbide nanowires’ addition on IMC growth behavior of pure Sn solder during solid–liquid diffusion

Mu-Lan Li,Su-Juan Zhong,Nan Jiang,Lei Zhang,Liang Zhang

doi:10.1007/s10854-021-06348-w

Mu-Lan Li, Su-Juan Zhong + Show 3 more

Open Access

https://doi.org/10.1007/s10854-021-06348-w

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Abstract

In this paper, various mass fractions (0, 0.2, 0.4, 0.6, 0.8, 1.0 wt%) of silicon carbide nanowires (SiC NWs) were incorporated into pure Sn solder to enhance the performances of Sn solder joint. The wetting behavior, shear strength, and intermetallic compound (IMC) growth mechanism of Sn–xSiC/Cu solder during solid–liquid diffusion at 250 °C were investigated systematically. The experimental results demonstrated that the wettability of Sn–xSiC/Cu solder had a significant improvement when the addition of SiC NWs was up to 0.6 wt%, and excessive additives would degrade the wettability of the composite solder. The formation of the Cu6Sn5 IMC layer was observed at the Sn–xSiC solder/Cu interface. Meanwhile, SiC NWs as additives were conducive to restraining the growth of interfacial IMC during soldering process and the IMC thickness overtly fell down after doping 0.8 wt% SiC NWs into Sn solder. Moreover, SiC NW addition would contribute to enhancing the mechanical performance of Sn solder joint. The fracture mechanism of solder joint changed from a mix of brittle and ductile fracture to a characteristic of typical ductile fracture.

Highlights

Sn-based solder, as a familiar material for the interconnection between substrates and parts of electron devices, provides for mechanical and electrical joints [1]
Sun et al [18] demonstrated that Cu atoms in Cu substrate could react with Sn atoms in Sn solder rapidly at high temperature and two different intermetallic compound (IMC) layers of the typical Cu6Sn5 and Cu3Sn were observed at the interface as the transient liquid phase bonding time increased
There were studies [17, 19] that indicated that 0.075 wt% carbon nanotubes (CNTs) or 0.7 wt% Cu nanoparticles as strengthening phases introduced into Sn solder decreased the interfacial Cu6Sn5 IMC thickness mostly

Summary

Introduction

Sn-based solder, as a familiar material for the interconnection between substrates and parts of electron devices, provides for mechanical and electrical joints [1]. Researchers usually selected micro/nano-metric materials as strengthened additives added into pure Sn solder to promote the reliability of solder joints, such as single metallic particles or elements (Ag, Bi, Cu, etc.) [14,15,16] and carbon-based materials [17]. Micrometric CuZnAl particles added to Sn solder could absorb on the surface of Sn atoms, prohibiting the Sn and Cu atoms from reacting and refraining interfacial surface IMC layer growth of Cu/Sn-0.5CuZnAl/Cu. there were studies [17, 19] that indicated that 0.075 wt% carbon nanotubes (CNTs) or 0.7 wt% Cu nanoparticles as strengthening phases introduced into Sn solder decreased the interfacial Cu6Sn5 IMC thickness mostly. After the specimens conducted the soldering process, the shear test was made use of SEM to observe fracture morphology

Results and discussion

Interfacial IMC layer growth

Mechanical property

Conclusions