时效过程中Sn-9Zn/Cu焊点的微观组织演化与界面反应机理

陈湜; CHEN Shi; 赵宁; ZHAO Ning

doi:10.48014/pcms.20250221001

时效过程中Sn-9Zn/Cu焊点的微观组织演化与界面反应机理

Microstructural Evolution and Interfacial Reaction Mechanisms of Sn-9Zn/Cu Solder Joints during Thermal Aging

中国材料科学进展 2025年第4卷第2期页码[25-33] 下载全文[10.5MB]

摘要

随着欧盟RoHS指令的实施, 电子制造业加速了无铅焊料的研发, Sn-9Zn合金因其接近传统Sn-37Pb合金的熔点并具有成本优势和优异的抗迁移性, 成为中温钎料的优选之一。然而, Sn-9Zn钎料与Cu焊盘的界面反应机制仍存在许多科学问题, 特别是在高温下的长期可靠性亟须探索。本研究针对Sn-9Zn/Cu焊点的高温服役环境, 设计了100℃和150℃下的加速老化实验, 并结合场发射扫描电镜 (FESEM) 和电子探针 (EPMA) 表征, 揭示了界面金属间化合物 (IMC) 的相组成、演化规律及元素扩散行为。研究表明, Sn-9Zn/Cu焊点在100℃下, Cu5Zn8相逐渐增厚并稳定。而在150℃下, 界面Cu5Zn8分解并出现缺口, 使钎料能够与Cu基板接触反应, 在基板中形成蚀坑状 Cu6 (Sn, Zn) 5, 这将显著影响焊点的可靠性。

Abstract

With the implementation of the EU RoHS directive, the electronics manufacturing industry has accelerated the development of lead-free solders. Sn-9Zn alloy has emerged as one of the preferred mid-temperature solders due to its melting point being close to that of the traditional Sn-37Pb alloy, as well as its cost-effectiveness and excellent resistance to electromigration. However, the interfacial reaction mechanism between Sn-9Zn solder and Cu pads remain poorly understood, especially regarding their long-term reliability under elevated temperatures. This study focuses on the interfacial microstructural evolution of Sn-9Zn/ Cu solder joints under high-temperature service conditions. Accelerated aging tests were conducted at 100℃ and 150℃. The interfacial morphology and elemental distribution were characterized using field-emission scanning electron microscopy (FESEM) and electron probe microanalysis (EPMA) . Results show that at 100℃, the Cu5Zn8 intermetallic compound (IMC) gradually thickens and remains stable. In contrast, at 150℃, the Cu5Zn8layer decomposed, resulting in interfacial voids that enable direct reaction between the solder and Cu substrate. This leads to the formation of pit-like Cu6 (Sn, Zn) 5 phases within the substrate, which could critically compromise the reliability of the solder joint

DOI

10.48014/pcms.20250221001

文章类型

研究性论文

收稿日期

2025-02-21

接收日期

2025-04-08

出版日期

2025-06-28

关键词

电子封装, Sn-9Zn钎料, 时效老化, 界面反应, 金属间化合物

Keywords

Electronics Packaging, Sn-Zn solder, thermal aging, interfacial reactions, intermetallic compounds

作者

陈湜, 赵宁^*

Author

CHEN Shi, ZHAO Ning^*

所在单位

大连理工大学材料科学与工程学院, 大连 116024

Company

School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China

浏览量

下载量

基金项目

本项研究得到了国家自然科学基金项目(资助号:52075072)、山东省重点研发计划(重大科技创新工程,资助号:2022CXGC020408)的资助

参考文献

[1] Han J, Chen H, Li M, et al. Shear deformation behaviors of Sn3. 5Ag lead-free solder samples[J]. Journal of Materials Science & Technology, 2013, 29(05): 471-479.
https://doi.org/10.1016/j.jmst.2013.01.012
[2] 杨扬, 陆皓, 余春, 等. 热老化条件下Sn3. 5Ag/Cu界面反应的研究[J]. 焊接, 2010(09): 39-42.
https://doi.org/10.3969/j.issn.1001-1382.2010.09.009
[3] 葛进国, 杨莉, 刘海祥, 等. Fe对Sn0. 7Cu无铅钎料显微组织和力学性能的影响[J]. 热加工工艺, 2016, 45(03): 205-206.
https://doi.org/10.14158/j.cnki.1001-3814.2016.03.057
[4] 赵元虎, 张元祥, 许杨剑, 等. Sn0. 7Cu无铅焊点的电迁移失效模拟及优化分析[J]. 电子元件与材料, 2015, 34(04): 59-63.
https://doi.org/10.14106/j.cnki.1001-2028.2015.04.015
[5] Chen P, Zhao X, Liu Y, et al. Aging resistance and mechanical properties of Sn3. 0Ag0. 5Cu solder bump joints with different bump shapes[J]. Rare Metals, 2021, 40(01): 225-230.
https://doi.org/10.1007/s12598-015-0612-4
[6] Tian, R, Tian, Y, Huang, Y, et al. Comparative study between the Sn-Ag-Cu/ENIG and Sn-Ag-Cu/ENEPIG solder joints under extreme temperature thermal shock [J]. Journal of Materials Science. Materials in Electronics, 2021, 32(6): 6890-6899.
https://doi.org/10.1007/s10854-021-05395-7.
[7] 杨林梅, 牟国琬. Sn3. 0Ag0. 5Cu/Cu流焊点界面化合物尺寸分布特征及生长机制[J]. 焊接学报, 2022, 43(04): 61-67.
https://doi.org/10.12073/j.hjxb.20210915001
[8] 闫鑫, 杨晓军, 谢濡泽, 等. In对Sn9Zn钎料润湿性能的影响[J]. 电子元件与材料, 2015, 34(08): 73-77.
https://doi.org/JournalArticle/5b3be6d3c095d70f00976372
[9] Zhang L, Fan Y, Sujuan Z. ZnO whiskers growth on the surface of Sn9Zn/Cu solder joints in concentrator silicon solar cells solder layer[J]. High Technology Letters, 2017, 23(03): 337-341.
https://doi.org/10.3772/j.issn.1006-6748.2017.03.016
[10] Zhao N. , Deng J. F. , Zhong Y. , et al. Abnormal intermetallic compound evolution in Ni/Sn/Ni and Ni/Sn- 9Zn/Ni micro solder joints under thermomigration[J]. Journal of Electronic Materials, 2017, 46(4): 1931-1936.
https://doi.org/10.1007/s11664-016-5149-2
[11] Huang M. L. , Zhang Z. J. , Zhao N. , et al. In situ study on reverse polarity effect in Cu/Sn-9Zn/Ni interconnect undergoing liquid-solid electromigration[J]. Journal of Alloys and Compounds, 2015(619): 667-675.
https://doi.org/10.1016/j.jallcom.2014.08.263
[12] Zhao N. , Wang M. Y. , Zhong Y. , et al. Effect of Zn content on Cu-Ni cross-interaction in Cu/Sn-xZn/Ni micro solder joints[J]. Journal of Materials Science- Materials in Electronics, 2018, 29(6): 5064-5073.
https://doi.org/10.1007/s10854-017-8469-y
[13] Zhou Z. H. , Liu, Y. C. Dong M. J. , et al. Microstructure and interface evolution of Sn-2. 5Bi-1. 4In-1Zn-0. 3Ag/ Cu joint during isothermal aging[J]. Journal of Materials Science-Materials in Electronics, 2013, 24(10): 4122-4128.
https://doi.org/10.1007/s10854-013-1370-4
[14] Zhang X. F. , Guo J. D. , Shang J. K. , Effects of electromigration on interfacial reactions in the Ni/Sn-Zn/ Cu solder interconnect[J]. Journal of Electronic Materials, 2009, 38(3): 425-429.
https://doi.org/10.1007/s11664-008-0594-1
[15] Liou W. K. , Yen Y. W. , Jao C. C. , Interfacial reactions of Sn-9Zn-xCu(x=1, 4, 7, 10)solders with Ni substrates[ J]. Journal of Electronic Materials, 2009, 38(11): 2222-2227.
https://doi.org/10.1007/s11664-009-0880-6
[16] C. S. Lee, F. S. Shieu, Growth of intermetallic compounds in the Sn-9Zn/Cu joint[J]. Journal of Electronic Materials, 2006, 35(8): 1660-1664.
https://doi.org/10.1007/s11664-006-0214-x
[17] Wu M, Wang S L, Yin L M, et al. Oxidation behavior and intermetallic compound growth dynamics of SAC305/Cu solder joints under rapid thermal shock [J]. Transactions of Nonferrous Metals Society of China, 2023, 33(10): 3054-3066.
https://doi.org/10.1016/S1003-6326(23)66317-4
[18] 涂文斌, 胡志华, 邹雨柔, 等. 时效时间和Sb添加对Sn- 9Zn-3Bi/Cu焊点界面金属间化合物生长行为的影响[J]. 材料导报, 2025, 39(06): 193-198.
https://doi.org/10.11896/cldb.23120193
[19] 吕娟, 赵麦群, 卢加飞, 等. 时效处理对Sn-9Zn/Cu界面组织及剪切性能的影响[J]. 电子工艺技术, 2009, 30(2): 70-73.
https://doi.org/10.3969/j.issn.1001-3474.2009.02.003
[20] 吕娟. Sn-9Zn系无铅焊锡合金的微合金化研究[D]. 西安: 西安理工大学, 2009.
[21] 田昕伟. 时效过程中Cu镀层及其焊点界面组织演变[D]. 大连: 大连理工大学, 2023

引用本文

陈湜, 赵宁. 时效过程中Sn-9Zn/Cu焊点的微观组织演化与界面反应机理[J]. 中国材料科学进展, 2025, 4(2): 25-33.

Citation

CHEN Shi, ZHAO Ning. Microstructural evolution and interfacial reaction mechanisms of Sn-9Zn/Cu solder joints during thermal aging[J]. Progress in Chinese Materials Sciences, 2025, 4(2): 25-33.