Characterization of the die-attach process via low-temperature reduction of Cu formate in air

  • Woo Lim Choi
  • Young Sung Kim
  • Ki-Seong Lee
  • Jong-Hyun LeeEmail author


For sinter-bonding wide-bandgap power devices to Cu finished metals in air, a low-cost material, i.e., a Cu complex paste containing mechanochemically synthesized Cu(II) formate, was prepared. Characteristics of the die-attach process were analyzed with respect to the bonding conditions. Cu nanoparticles were formed in situ by the reduction of Cu(II) formate during heating for the attachment. Sinter-bonding between the nanoparticles and Cu metallization was accelerated by the exothermic heat generated by the Cu complex. As a result, high-speed bonding (1–3 min) was achieved, which prevented severe oxidation of the reduced Cu particles and Cu finish even in air. With the application of an external pressure of 20 MPa, the Cu chips were bonded in only 1 min at 225 °C with a resulting shear strength of 23 MPa. Although the pressure decreased to 13 MPa, bonding occurred within 3 min at 225 and 210 °C, with excellent shear strength exceeding 71 and 39 MPa, respectively.



This work was supported by the Materials & Components Technology Development Program (10080187) funded by the Ministry of Trade, Industry & Energy (MI, Korea). The authors also thank the Korean Basic Science Institute (KBSI), Busan Center for their assistance in the thermogravimetric analysis.


  1. 1.
    H.S. Chin, K.Y. Cheong, A.B. Ismail, A review on die attach materials for SiC-based high-temperature power devices. Metal. Mater. Trans. B 41, 824–832 (2010)CrossRefGoogle Scholar
  2. 2.
    J.G. Bai, J. Yin, Z.Y. Zhang, G.Q. Lu, J.D. van Wyk, High-temperature operation of SiC power devices by low-temperature sintered silver die-attachment. IEEE Trans. Adv. Packag. 30, 506–510 (2007)CrossRefGoogle Scholar
  3. 3.
    Lu, G.-Q., Calata, J.N., Zhang, Z., Bai, J.G. (2004). A lead-free, Low-temperature sintering die-attach technique for high-performance and high-temperature packaging, In: Proceedings of 6th IEEE CPMT Conf. on High Density Microsystem Design and Packaging and Component Failure Analysis (HDP ‘04), IEEE, Shanghai, pp. 42–46Google Scholar
  4. 4.
    Z. Zhang, G.Q. Lu, Pressure-assisted low-temperature sintering of silver paste as an alternative die-attach solution to solder reflow. IEEE Trans. Electron. Packag. Manuf. 25, 279–283 (2002)CrossRefGoogle Scholar
  5. 5.
    G. Zeng, S. McDonald, K. Nogita, Development of high-temperature solders. Microelectron. Reliab. 52, 1306–1322 (2012)CrossRefGoogle Scholar
  6. 6.
    V. Chidambaram, J. Hattel, J. Hald, High-temperature lead-free solder alternatives. Microelectron. Eng. 88, 981–989 (2011)CrossRefGoogle Scholar
  7. 7.
    M. Pouranvari, A. Ekrami, A.H. Kokabi, Effect of bonding temperature on microstructure development during TLP bonding of a nickel base superalloy. J. Alloys Compd. 469, 270–275 (2009)CrossRefGoogle Scholar
  8. 8.
    P. Ning, T.G. Lei, F. Wang, G.-Q. Lu, K.D.T. Ngo, K. Rajashekara, A novel high-temperature planar package for SiC multichip phase-leg power module. IEEE Trans. Power Electron. 25, 2059–2067 (2010)CrossRefGoogle Scholar
  9. 9.
    S.W. Yoon, M.D. Glover, K. Shiozaki, Nickel–tin transient liquid phase bonding toward high-temperature operational power electronics in electrified vehicles. IEEE Trans. Power Electron. 28, 2448–2456 (2013)CrossRefGoogle Scholar
  10. 10.
    H.A. Mustain, W.D. Brown, S.S. Ang, Transient liquid phase die attach for high-temperature silicon carbide power devices. IEEE Trans. Compon. Packag. Technol. 33, 563–570 (2010)CrossRefGoogle Scholar
  11. 11.
    H. Shao, A. Wu, Y. Bao, Y. Zhao, G. Zou, Microstructure characterization and mechanical behavior for Ag3Sn joint produced by foil-based TLP bonding in air atmosphere. Mater. Sci. Eng., A 680, 221–231 (2017)CrossRefGoogle Scholar
  12. 12.
    A.A. Bajwa, J. Wilde, Reliability modeling of Sn–Ag transient liquid phase die-bonds for high-power SiC devices. Microelectron. Reliab. 60, 116–125 (2016)CrossRefGoogle Scholar
  13. 13.
    C.H. Lee, E.B. Choi, J.-H. Lee, Characterization of novel high-speed die attachment method at 225 °C using submicrometer Ag-coated Cu particles. Scr. Mater. 150, 7–12 (2018)CrossRefGoogle Scholar
  14. 14.
    S. Fu, Y. Mei, G.-Q. Lu, X. Li, G. Chen, X. Chen, Pressureless sintering of nanosilver paste at low temperature to join large area (≥ 100 mm2) power chips for electronic packaging. Mater. Lett. 128, 42–45 (2014)CrossRefGoogle Scholar
  15. 15.
    X. Liu, H. Nishikawa, Low-pressure Cu-Cu bonding using in situ surface-modified microscale Cu particles for power device packaging. Scr. Mater. 120, 80–84 (2016)CrossRefGoogle Scholar
  16. 16.
    Y. Jianfeng, Z. Guisheng, H. Anming, Y.N. Zhou, Preparation of PVP coated Cu NPs and the application for low-temperature bonding. J. Mater. Chem. 21, 15981–15986 (2011)CrossRefGoogle Scholar
  17. 17.
    S. Kaimori, T. Nonaka, A. Mizoguchi, The development of Cu bonding wire with oxidation-resistant metal coating. IEEE Trans. Adv. Packag. 29, 227–231 (2006)CrossRefGoogle Scholar
  18. 18.
    A. Yabuki, N. Arriffin, M. Yanase, Low-temperature synthesis of copper conductive film by thermal decomposition of copper–amine complexes. Thin Solid Films 519, 6530–6533 (2011)CrossRefGoogle Scholar
  19. 19.
    A. Yabuki, S. Tanaka, Electrically conductive copper film prepared at low temperature by thermal decomposition of copper amine complexes with various amines. Mater. Res. Bull. 47, 4107–4111 (2012)CrossRefGoogle Scholar
  20. 20.
    M. Joo, B. Lee, S. Jeong, M. Lee, Laser sintering of Cu paste film printed on polyimide substrate. Appl. Surf. Sci. 25, 521–524 (2011)CrossRefGoogle Scholar
  21. 21.
    B. Lee, S. Jeong, Y. Kim, I. Jeong, K. Woo, J. Moon, Hybrid copper complex-derived conductive patterns printed on polyimide substrates. Met. Mater. Int. 18, 493–498 (2012)CrossRefGoogle Scholar
  22. 22.
    M. Joo, B. Lee, S. Jeong, M. Lee, Comparative studies on thermal and laser sintering for highly conductive Cu films printable on plastic substrate. Thin Solid Films 520, 2878–2883 (2012)CrossRefGoogle Scholar
  23. 23.
    Z. Zhang, C. Chen, Y. Yang, H. Zhang, D. Kim, T. Sugahara, S. Nagao, K. Suganuma, Low-temperature and pressureless sinter joining of Cu with micron/submicron Ag particle paste in air. J. Alloys Compd. 780, 435–442 (2019)CrossRefGoogle Scholar
  24. 24.
    D. Stoilova, Hydrogen bonding systems in metal(II) formate dihydrates, M(HCOO)2·2H2O (M = Mg, Mn, Co, Ni, Cu, and Zn). Double matrix infrared spectroscopy. J. Mol. Struct. 798, 141–148 (2006)CrossRefGoogle Scholar
  25. 25.
    M.A. Mohamed, A.K. Galwey, S.A. Halawy, Kinetic and thermodynamic studies of the nonisothermal decomposition of anhydrous copper(II) formate in different gas atmospheres. Thermochim. Acta 411, 13–20 (2004)CrossRefGoogle Scholar
  26. 26.
    D.M. Bastidas, V.M.L. Iglesia, E. Cano, S. Fajardo, J.M. Bastidas, Kinetic study of formate compounds developed on copper in the presence of formic acid vapor. J. Electrochem. Soc. 155, 578–582 (2008)CrossRefGoogle Scholar
  27. 27.
    V. Rosenband, A. Gany, Preparation of nickel and copper submicrometer particles by pyrolysis of their formates. J. Mater. Proc. Technol. 153–154, 1058–1061 (2004)CrossRefGoogle Scholar
  28. 28.
    J. Sopousek, J. Bursik, J. Zalesak, Z. Pesina, Silver nanoparticles sintering at low temperature on a copper substrate: in situ characterization under inert atmosphere and air. J. Min. Metall. Sect. B-Metall. 48, 63–71 (2012)CrossRefGoogle Scholar
  29. 29.
    S. Magdassi, M. Grouchko, O. Berezin, A. Kamyshny, Triggering the sintering of silver nanoparticles at room temperature. ACS Nano 4, 1943–1948 (2010)CrossRefGoogle Scholar
  30. 30.
    A. Hu, J.Y. Guo, H. Alarifi, G. Patane, Y. Zhou, G. Compagnini, C.X. Xu, Low temperature sintering of Ag nanoparticles for flexible electronics packaging. Appl. Phys. Lett. 97, 153117 (2010)CrossRefGoogle Scholar
  31. 31.
    N.-G. Park, K.M. Kim, M.G. Kang, K.S. Ryu, S.H. Chang, Y.-J. Shin, Chemical sintering of nanoparticles: a methodology for low-temperature fabrication of dye-sensitized films. Adv. Mater. 17, 2349–2353 (2005)CrossRefGoogle Scholar
  32. 32.
    J. Ryu, H.-S. Kim, H.T. Hahn, Reactive sintering of copper nanoparticles using intense pulsed light for printed electronics. J. Electron. Mater. 40, 42–50 (2011)CrossRefGoogle Scholar
  33. 33.
    R. Zhang, K.-S. Moon, W. Lin, C.P. Wong, Preparation of highly conductive polymer nanocomposites by low temperature sintering of silver nanoparticles. J. Mater. Chem. 20, 2018–2023 (2010)CrossRefGoogle Scholar

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© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  • Woo Lim Choi
    • 1
  • Young Sung Kim
    • 1
  • Ki-Seong Lee
    • 1
  • Jong-Hyun Lee
    • 1
    Email author
  1. 1.Department of Materials Science and EngineeringSeoul National University of Science and TechnologySeoulRepublic of Korea

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