Abstract In this work, multi-walled carbon nanotubes (MWCNTs) reinforced Sn-5Sb/Cu composite solder joints were synthesized and the effects of MWCNTs addition on the microstructure evolution and hardness of the Sn-5Sb solder alloy during various thermal aging conditions were investigated. After conducting a thorough microstructural analysis, the SbSn and Cu6Sn5 intermetallic compounds (IMCs) were observed in the β-Sn matrix of the composite solder joints subjected to reflow soldering while the latter was also present at the solder/Cu interface. However, after subjecting the composite solder joints to isothermal aging, the Cu3Sn IMC emerged between the Cu6Sn5 IMC at the solder/Cu interface and the Cu substrate. With the promising properties exhibited by MWCNTs as a reinforcement material, experimental results showed that MWCNTs refined the bulk solder microstructure and inhibited growth of the interfacial IMC layer in the Sn-5Sb-xCNT/Cu samples. In general, the composite sample reinforced with 0.05 wt% MWCNTs showed the least IMC layer thickness and diffusion coefficient in the ranges of 2.6–11.99 μm and 1.07 × 10−14-14.9 × 10−14 cm2/s respectively. Meanwhile, the strengthening mechanism triggered by MWCNTs addition was clearly evident in the MWCNT-reinforced Sn-5Sb/Cu as superior hardness values within a range of 20.6–15.3 HV were registered for the as-soldered and aged composite solder joints with 0.05 wt% MWCNTs reinforcement.

中文翻译：

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不同热老化条件下多壁碳纳米管增强Sn-5Sb/Cu复合焊点组织演变及硬度

摘要 本工作合成了多壁碳纳米管 (MWCNTs) 增强的 Sn-5Sb/Cu 复合焊点，并研究了 MWCNTs 添加对 Sn-5Sb 焊料合金在不同热老化条件下微观结构演变和硬度的影响。 . 在进行彻底的微观结构分析后，在复合焊点的 β-Sn 基体中观察到 SbSn 和 Cu6Sn5 金属间化合物（IMCs）进行回流焊接，而后者也存在于焊料/Cu 界面。然而，在对复合焊点进行等温老化后，Cu3Sn IMC 出现在焊料/Cu 界面处的 Cu6Sn5 IMC 和 Cu 基板之间。由于多壁碳纳米管作为增强材料所表现出的有前途的特性，实验结果表明，MWCNT 细化了块状焊料微观结构并抑制了 Sn-5Sb-xCNT/Cu 样品中界面 IMC 层的生长。一般来说，用 0.05 wt% MWCNTs 增强的复合材料样品显示出最小的 IMC 层厚度和扩散系数，分别在 2.6-11.99 μm 和 1.07 × 10-14-14.9 × 10-14 cm2/s 范围内。同时，添加多壁碳纳米管触发的强化机制在多壁碳纳米管增强的 Sn-5Sb/Cu 中很明显，因为焊接和老化复合焊点的硬度值在 20.6-15.3 HV 范围内，0.05 wt% MWCNTs 增强。05 wt% MWCNTs 在 2.6-11.99 μm 和 1.07 × 10-14-14.9 × 10-14 cm2/s 范围内表现出最小的 IMC 层厚度和扩散系数。同时，添加多壁碳纳米管触发的强化机制在多壁碳纳米管增强的 Sn-5Sb/Cu 中很明显，因为焊接和老化复合焊点的硬度值在 20.6-15.3 HV 范围内，0.05 wt% MWCNTs 增强。05 wt% MWCNTs 在 2.6-11.99 μm 和 1.07 × 10-14-14.9 × 10-14 cm2/s 范围内表现出最小的 IMC 层厚度和扩散系数。同时，添加多壁碳纳米管触发的强化机制在多壁碳纳米管增强的 Sn-5Sb/Cu 中很明显，因为焊接和老化复合焊点的硬度值在 20.6-15.3 HV 范围内，0.05 wt% MWCNTs 增强。