Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-19T08:30:11.184Z Has data issue: false hasContentIssue false
  • English
  • Français

Reliability analysis of Au–Sn flip-chip solder bump fabricated by co-electroplating

Published online by Cambridge University Press:  03 March 2011

Jeong-Won Yoon ,
Hyun-Suk Chun  and
Seung-Boo Jung
Jeong-Won Yoon
Affiliation:
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746, Korea
Hyun-Suk Chun
Affiliation:
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746, Korea
Seung-Boo Jung*
Affiliation:
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746, Korea
*
a) Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

In this study, we fabricated eutectic Au–Sn (Au–20 wt% Sn) flip-chip solder bumps from a single electroplating bath. After reflowing, the average diameter of the solder bump was approximately 80 μm. The (Ni,Au)3Sn2 phase was initially formed when the liquid Au–Sn solder reacted with the Ni UBM (under bump metallization). After aging at 150 °C, the (Ni,Au)3Sn2 intermetallic compound (IMC), which formed at the interface during reflow, was fully transformed into the (Au,Ni)Sn IMC due to the restricted supply of Ni atoms from the UBM to the interface. On the other hand, after aging at 250 °C for 1000 h, two IMC layers, (Au,Ni)Sn and (Ni,Au)3Sn2, were formed at the interface. The lower (Ni,Au)3Sn2 phase was formed when the (Au,Ni)Sn phase reacted with the Ni UBM. The interfacial (Au,Ni)Sn IMC grew with the preferential consumption of the available δ-phase in the solder matrix. Eventually, the ζ-phase covered most of the interfacial layer. In the bump shear tests, the Au–Sn/Ni joint aged at 150 °C fractured through the bulk of the solder, confirming the mechanical reliability of the interface. In contrast, the Au–Sn/Ni joint aged at 250 °C fractured along the interface, thereby demonstrating brittle failure, possibly a result of the brittle IMC layer at the interface.

Keywords

JoiningMicroelectronicsPackaging
Type
Articles
Information
Journal of Materials Research , Volume 22 , Issue 5 , May 2007 , pp. 1219 - 1229
Copyright
Copyright © Materials Research Society 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1Tew, J.W.R., Shi, X.Q., and Yuan, S.: Au/Sn solder for face-down bonding of AlGaAs/GaAs ridge waveguide laser diodes. Mater. Lett. 58, 2695 (2004).Google Scholar
2Tsai, J.Y., Chang, C.W., Shieh, Y.C., Hu, Y.C., and Kao, C.R.: Controlling the microstructures from the gold-tin reaction. J. Electron. Mater. 34, 182 (2005).Google Scholar
3Katz, A., Wang, K.W., Baiocchi, F.A., Dautremont-Smith, W.C., Lane, E., Luftman, H.S., Varma, R.R., and Curnan, H.: Ti/Pt/Au–Sn metallization scheme for bonding of InP-based laser diodes to chemical vapor deposited diamond submounts. Mater. Chem. Phys. 33, 281 (1993).Google Scholar
4Pittroff, W., Barnikow, J., Klein, A., Kurpas, P., Merkel, U., Vogel, K., Würfl, J., and Kuhmann, J.: Flip chip mounting of laser diodes with Au/Sn solder bumps: Bumping, self-alignment and laser behavior. IEEE 1997 Electronic Components and Technology Conference (IEEE, Piscataway, NJ, 1997), p. 1235.Google Scholar
5Doesburg, J. and Ivey, D.G.: Microstructure and preferred orientation of Au–Sn alloy plated deposits. Mater. Sci. Eng., B 78, 44 (2000).Google Scholar
6Djurfors, B. and Ivey, D.G.: Microstructural characterization of pulsed electrodeposited Au/Sn alloy thin films. Mater. Sci. Eng., B 90, 309 (2002).Google Scholar
7Djurfors, B. and Ivey, D.G.: Pulsed electrodeposition of the eutectic Au/Sn solder for optoelectronic packaging. J. Electron. Mater. 30, 1249 (2001).Google Scholar
8Tsai, J.Y., Chang, C.W., Ho, C.E., Lin, Y.L., and Kao, C.R.: Microstructure evolution of gold-tin eutectic solder on Cu and Ni substrates. J. Electron. Mater. 35, 65 (2006).Google Scholar
9Kim, D. and Lee, C.C.: Fluxless flip-chip Sn–Au solder interconnect on thin Si wafers and Cu laminated polyimide films. Mater. Sci. Eng., A 416, 74 (2006).Google Scholar
10Elger, G., Hutter, M., Oppermann, H., Aschenbrenner, R., Reichl, H., and Jäger, E.: Development of an assembly process and reliability investigations for flip-chip LEDs using AuSn soldering. Microsystem Technol. 7, 239 (2002).Google Scholar
11Lee, C.H., Wong, Y.M., Doherty, C., Tai, K.L., Lane, E., Bacon, D.D., Baiocchi, F., and Katz, A.: Study of Ni as a barrier metal in AuSn soldering application for laser chip/submount assembly. J. Appl. Phys. 72, 3808 (1992).Google Scholar
12Chromik, R.R., Wang, D-N., Shugar, A., Limata, L., Notis, M.R., and Vinci, R.P.: Mechanical properties of intermetallic compounds in the Au–Sn system. J. Mater. Res. 20, 2161 (2005).Google Scholar
13Kim, S.S., Kim, J.H., Booh, S.W., Kim, T.G., and Lee, H.M.: Microstructural evolution of joint interface between eutectic 80Au–20Sn solder and UBM. Mater. Trans. 46, 2400 (2005).Google Scholar
14Yoon, J.W., Chun, H.S., Koo, J.M., and Jung, S.B.: Au–Sn flip-chip solder bump for microelectronic and optoelectronic applications. Microsystem Technol. (2007, in-press).Google Scholar
15Song, H.G., Morris, J.W. Jr., and McCormack, M.T.: The microstructure of ultrafine eutectic Au–Sn solder joints on Cu. J. Electron. Mater. 29, 1038 (2000).Google Scholar
16Kim, J., Kim, D., and Lee, C.C.: Fluxless flip-chip solder joint fabrication using electroplated Sn-rich Sn–Au structures. IEEE Trans. Advan. Packag. 29, 473 (2006).Google Scholar
17Yoon, J.W. and Jung, S.B.: Interfacial reactions and shear strength on Cu and electrolytic Au/Ni metallization with Sn–Zn solder. J. Mater. Res. 21, 1590 (2006).Google Scholar
18Matijasevic, G.S., Lee, C.C., and Wang, C.Y.: Au–Sn alloy phase diagram and properties related to its use as a bonding medium. Thin Solid Films 223, 276 (1993).Google Scholar
19Anhöck, S., Oppermann, H., Kallmayer, C., Aschenbrenner, R., Thomas, L., and Reichl, H.: Investigations of Au/Sn alloys on different end-metallizations for high temperature applications, inProceeding of the 1998 IEEE/CPMT Berlin International Electronics Manufacturing Technology Symposium (IEEE, Piscataway, NJ, 1998), p. 156.Google Scholar
20Lee, K.Y., Li, M., and Tu, K.N.: Growth and ripening of (Au,Ni)Sn4 phase in Pb-free and Pb-containing solders on Ni/Au metallization. J. Mater. Res. 18, 2562 (2003).Google Scholar
21Song, H.G., Ahn, J.P., and Morris, J.W. Jr.: The microstructure of eutectic Au–Sn solder bumps on Cu/electroless Ni/Au. J. Electron. Mater. 30, 1083 (2001).Google Scholar
22Chen, W.M., McCloskey, P., and O’Mathuna, S.C.: Isothermal aging effects on the microstructure and solder bump shear strength of eutectic Sn37Pb and Sn3.5Ag solders. Microelectron. Reliab. 46, 896 (2006).Google Scholar