Grain refinement and interfacial IMCs suppression via Zn addition to enhance the mechanical properties of Cu/Sn-58Bi/Cu microbump

IF 2.8 4区工程技术 Q2 ENGINEERING, ELECTRICAL & ELECTRONIC

Journal of Materials Science: Materials in Electronics Pub Date : 2025-09-27 DOI:10.1007/s10854-025-15748-1

Pin-Ling Lin, Zih-You Wu, Yin-Ku Lee, Zi-Xu Chen, Ta-Wei Lin, Po-Yu Chen, Jenq-Gong Duh

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引用次数: 0

Abstract

The continuous downscaling of microbump dimensions to sub-10 μm presents critical challenges to joint reliability in advanced electronic packaging. In such fine-pitch systems, applying low-temperature solders such as Sn-58Bi is considered to minimize thermal stress and ensure process compatibility. However, excessive growth of interfacial intermetallic compounds (IMCs), as well as the inherent brittleness and grain coarsening of Sn-58Bi solder, significantly degrade mechanical integrity. To address these limitations and improve mechanical properties, this study investigates the effect of Zn addition into Cu substrates on the microstructure and mechanical performance of Cu/Sn-58Bi/Cu microbumps. Doping Zn resulted in the formation of a Cu(Zn,Sn) layer, which served as a diffusion barrier to inhibit interfacial IMC growth. It also refined the eutectic microstructure through Zn diffusion into the solder. Shear tests revealed that Cu-36Zn/Sn-58Bi/Cu-36Zn samples exhibited improved mechanical performance compared to Cu/Sn-58Bi/Cu samples, with an increase of 20.5% in shear strength and 31.1% in energy absorption. Fracture analyses were also conducted to elucidate the mechanisms behind the strengthening effect of Zn.

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Zn对Cu/Sn-58Bi/Cu微凸包力学性能的细化和界面IMCs抑制作用

微凸点尺寸不断缩小到10 μm以下，对先进电子封装中的接头可靠性提出了严峻的挑战。在这种细间距系统中，采用Sn-58Bi等低温焊料可以最大限度地减少热应力并确保工艺兼容性。然而，界面金属间化合物（IMCs）的过度生长，以及Sn-58Bi焊料固有的脆性和晶粒粗化，严重降低了Sn-58Bi焊料的机械完整性。为了解决这些局限性并提高力学性能，本研究研究了在Cu衬底中添加Zn对Cu/Sn-58Bi/Cu微凸块的微观结构和力学性能的影响。掺杂Zn可形成Cu（Zn,Sn）层，Cu（Zn,Sn）层是抑制界面IMC生长的扩散屏障。通过Zn向焊料扩散，使共晶组织细化。剪切试验结果表明，Cu- 36zn /Sn-58Bi/Cu- 36zn试样的力学性能较Cu/Sn-58Bi/Cu试样有所提高，剪切强度提高20.5%，能量吸收提高31.1%。通过断口分析，阐明了Zn的强化作用机制。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Materials Science: Materials in Electronics 工程技术-材料科学：综合

CiteScore

5.00

自引率

7.10%

发文量

1931

审稿时长

2 months

期刊介绍： The Journal of Materials Science: Materials in Electronics is an established refereed companion to the Journal of Materials Science. It publishes papers on materials and their applications in modern electronics, covering the ground between fundamental science, such as semiconductor physics, and work concerned specifically with applications. It explores the growth and preparation of new materials, as well as their processing, fabrication, bonding and encapsulation, together with the reliability, failure analysis, quality assurance and characterization related to the whole range of applications in electronics. The Journal presents papers in newly developing fields such as low dimensional structures and devices, optoelectronics including III-V compounds, glasses and linear/non-linear crystal materials and lasers, high Tc superconductors, conducting polymers, thick film materials and new contact technologies, as well as the established electronics device and circuit materials.