Effect of adding Ce on interfacial reactions between Sn-3.0Ag-0.5Cu solder and Cu substrate

  • Bin Lu (卢 斌)Email author
  • Hui Li (栗 慧)
  • Juan-hui Wang (王娟辉)
  • Hua-wei Zhu (朱华伟)
  • Xian-he Jiao (焦羡贺)


The formation and the growth of Cu-Sn intermetallic compound (IMC) layer at the interface between Sn-3.0Ag-0.5Cu-xCe solder and Cu substrate during soldering and aging were studied. The results show that Cu6Sn5 IMC is observed at the interface between solder and Cu substrate in all conditions. After aging for 120 h, the Cu3Sn IMC is then obtained. With increasing aging time, the scalloped Cu6Sn5 structure changes to a plate structure. The Cu3Sn film always forms with a relatively planar interface. By adding a small amount of the rare earth element Ce (only 0.1%, mass fraction) into the Sn-3.0Ag-0.5Cu solder alloy, the growth rate of the Cu-Sn IMC at the interface of solder alloy system is decreased. When the time exponent is approximately 0.5, the growth of the IMC layer is mainly controlled by a diffusion over the studied time range.

Key words

intermetallic compound interface Sn-3.0Ag-0.5Cu solder rare earth element 


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  1. [1]
    KIM K S, HUH S H, SUGANUMA K. Effects of fourth alloying additive on microstructures and tensile properties of Sn-Ag-Cu alloy and joints with Cu [J]. Microelectronics Reliability, 2003, 43(2):259–267.CrossRefGoogle Scholar
  2. [2]
    CHEN W T, LEE S W, YIP M C. Mechanical properties and intermetallic compound formation at the Sn/Ni and Sn-0.7wt%/Ni joints [J]. Journal of Electronic Materials, 2003, 32(11): 1284–1289.CrossRefGoogle Scholar
  3. [3]
    YU D Q, WANG L. The growth and roughness evolution of intermetallic compounds of Sn-Ag-Cu/Cu interface during soldering reaction [J]. Journal of Alloys and Compounds, 2008, 458(4/2): 542–547.CrossRefGoogle Scholar
  4. [4]
    GHOSH G. Interfacial microstructure and the kinetics of interfacial reaction in diffusion couples between Sn-Pb solder and Cu/Ni/Pd metallization [J]. Acta Materialia, 2000, 48(14): 3719–3738.CrossRefGoogle Scholar
  5. [5]
    LI Xiao-yan, YAN Yong-chang, SHI Yao-wu. Influence of IMC on the interface failure of Sn-Ag-Cu/Cu solder joint [J]. Journal of Mechanical Strength, 2005, 27(5): 666–671.Google Scholar
  6. [6]
    YU D Q, WU C M L, LAW C M T, WANG L, LAI J K L. Intermetallic compounds growth between Sn-3.5Ag lead-free solder and Cu substrate by dipping method [J]. Journal of Alloys and Compounds, 2005, 392(1/2): 192–199.CrossRefGoogle Scholar
  7. [7]
    YOON J W, KIM S W, JUNG S B. Interfacial reaction and mechanical properties of eutectic Sn-0.7Cu/Ni BGA solder joints during isothermal long-term aging [J]. Journal of Alloys and Compounds, 2005, 391(1/2): 82–89.CrossRefGoogle Scholar
  8. [8]
    MA X, QIAN Y Y, YOSHIDA F. Effect of La on the Cu-Sn intermetallic compound (IMC) growth and solder joint reliability [J]. Journal of Alloys and Compounds, 2002, 334(1/2): 224–227.CrossRefGoogle Scholar
  9. [9]
    WUA C M L. Properties of lead-free solder alloys with rare earth element additions [J]. Materials Science and Engineering Report, 2004, 44: 1–44.CrossRefGoogle Scholar
  10. [10]
    YOON J W, JUNG S B. Investigation of interfacial reactions between Sn-5Bi solder and Cu substrate [J]. Journal of Alloys and Compounds, 2003, 359(1/2): 202–208.CrossRefGoogle Scholar
  11. [11]
    YOON J W, LEE Y H, KIM D G, KANG H B, SUH S J, YANG C W, LEE C B, JUNG J W, YOO C S, JUNG S B. Intermetallic compound layer growth at the interface between Sn-Cu-Ni solder and Cu substrate [J]. Journal of Alloys and Compounds, 2004, 381(1/2):151–157.CrossRefGoogle Scholar
  12. [12]
    HIROSHI N, JIN Y P, TADASHI T. Interfacial reaction between Su-0.7Cu(-Ni) solder and Cu substrate [J]. Journal of Electronic Materials, 2006, 35(5): 1127–1132.CrossRefGoogle Scholar
  13. [13]
    PAKASH K H, SITHARAN T. Interface reaction between copper and molten Sn-Pn solders [J]. Acta Materialia, 2001, 49(13):2481–2489.CrossRefGoogle Scholar
  14. [14]
    LI Bo, SHI Yao-wu, LEI Yong-ping. Effect of rare element addition on the microstructure of Sn-Ag-Cu solder joint [J]. Journal of Electronic Materials, 2006, 34(3): 217–224.CrossRefGoogle Scholar
  15. [15]
    TU X N, THOMPSON R D. Kinetics of interfacial reaction in bimetallic Cu-Sn thin films [J]. Acta Metallurgica Materialia, 1982, 30(5): 947–952.CrossRefGoogle Scholar
  16. [16]
    LAW C M T, WU C M L, YU D Q. Microstructure, solderability, and growth of intermetallic compounds of Sn-Ag-Cu-Re lead-free solder alloys [J]. Journal of Electronic Materials, 2006, 35(1): 89–93.CrossRefGoogle Scholar
  17. [17]
    BO Song-bai, CHEN Yan, LÜ Xiao-chun. Thermodynamics calculation and preliminary of the Sn-Ag-Cu-Ce Lead-free solder [J]. Transactions of the China Welding Institution, 2005, 26(5): 20–22.Google Scholar
  18. [18]
    BO Song-bai, CHEN Yan, LÜ Xiao-chun. The calculation and application of activity interaction parameter in the Lead-free solder [J].Transactions of the China Welding Institution, 2005, 26(4):45–47.Google Scholar

Copyright information

© Central South University Press and Springer-Verlag GmbH 2008

Authors and Affiliations

  • Bin Lu (卢 斌)
    • 1
    Email author
  • Hui Li (栗 慧)
    • 1
  • Juan-hui Wang (王娟辉)
    • 1
  • Hua-wei Zhu (朱华伟)
    • 1
  • Xian-he Jiao (焦羡贺)
    • 1
  1. 1.School of Materials Science and EngineeringCentral South UniversityChangshaChina

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