Hostname: page-component-7c8c6479df-fqc5m Total loading time: 0 Render date: 2024-03-29T13:03:06.755Z Has data issue: false hasContentIssue false

Microstructural evolution and interfacial reactions of fluxless-bonded Au-20Sn/Cu solder joint during reflow and aging

Published online by Cambridge University Press:  31 January 2011

Jeong-Won Yoon
Affiliation:
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Jangan-gu, Suwon, Gyeonggi-do 440-746, Korea
Hyun-Suk Chun
Affiliation:
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Jangan-gu, Suwon, Gyeonggi-do 440-746, Korea
Hoo-Jeong Lee
Affiliation:
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Jangan-gu, Suwon, Gyeonggi-do 440-746, Korea
Seung-Boo Jung*
Affiliation:
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Jangan-gu, Suwon, Gyeonggi-do 440-746, Korea
*
a)Address all correspondence to this author. e-mail: sbjung@skku.ac.kr
Get access

Abstract

The microstructural evolution and interfacial reactions of fluxless-bonded, Au-20wt%Sn/Cu solder joint were investigated during reflow and aging. After reflowing at 310 °C, only one thick and irregularly shaped ζ(Cu) layer was formed at the interface. After the prolonged reflow reaction, the AuCu layer was formed between the ζ(Cu) layer and the Cu substrate. During reflowing, the Cu substrate reacted primarily with the ζ-phase in the solder matrix. The solid-state interfacial reaction was much faster at 250 °C than at 150 °C. After aging at 250 °C for 100 h, thick ζ(Cu), AuCu and AuCu3 IMC layers were formed at the interface. The formation of the AuCu3 intermetallic compound (IMC) was caused by Cu enrichment at the AuCu/Cu layer interface. After aging for 500 h, cracks were observed inside the interfacial AuCu layer. The study results clearly demonstrate the need for an alternative surface finish on Cu, to ensure the high temperature reliability of the Au-20Sn/Cu solder joint.

Type
Articles
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

1Matijasevic, G.S., Wang, C.Y.Lee, C.C.: Void free bonding of large silicon dice using gold-tin alloys. IEEE Trans. Comp., Hybrids. Manuf. Technol. 13, 1128 1990Google Scholar
2Tsai, J.Y., Chang, C.W., Shieh, Y.C., Hu, Y.C.Kao, C.R.: Controlling the microstructures from the gold-tin reaction. J. Electron. Mater. 34, 182 2005Google Scholar
3Katz, A., Wang, K.W., Baiocchi, F.A., Dautremont-Smith, W.C., Lane, E., Luftman, H.S., Varma, R.R.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 1993CrossRefGoogle Scholar
4Pittroff, W., Barnikow, J., Klein, A., Kurpas, P., Merkel, U., Vogel, K., Würfl, J.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 1235 (1997)Google Scholar
5Doesburg, J.Ivey, D.G.: Microstructure and preferred orientation of Au-Sn alloy plated deposits. Mater. Sci. Eng., B 78, 44 2000CrossRefGoogle Scholar
6Djurfors, B.Ivey, D.G.: Microstructural characterization of pulsed electrodeposited Au/Sn alloy thin films. Mater. Sci. Eng., B 90, 309 2002Google Scholar
7Yoon, J.W., Chun, H.S.Jung, S.B.: Reliability analysis of Au-Sn flip-chip solder bump fabricated by co-electroplating. J. Mater. Res. 22(5), 1219 2007CrossRefGoogle Scholar
8Djurfors, B.Ivey, D.G.: Pulsed electrodeposition of the eutectic Au/Sn solder for optoelectronic packaging. J. Electron. Mater. 30, 1249 2001CrossRefGoogle Scholar
9Tsai, J.Y., Chang, C.W., Ho, C.E., Lin, Y.L.Kao, C.R.: Microstructure evolution of gold-tin eutectic solder on Cu and Ni substrates. J. Electron. Mater. 35, 65 2006CrossRefGoogle Scholar
10Kim, D.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 2006CrossRefGoogle Scholar
11Lee, C.H., Wong, Y.M., Doherty, C., Tai, K.L., Lane, E., Bacon, D.D., Baiocchi, F.Katz, A.: Study of Ni as a barrier metal in AuSn soldering application for laser chip/submount assembly. J. Appl. Phys. 72, 3808 1992Google Scholar
12Chromik, R.R., Wang, D-N., Shugar, A., Limata, L., Notis, M.R.Vinci, R.P.: Mechanical properties of intermetallic compounds in the Au-Sn system. J. Mater. Res. 20, 2161 2005CrossRefGoogle Scholar
13Massalski, T.B.: Binary Alloy Phase Diagrams ASM International Materials Park, OH 1990 433Google Scholar
14Yoon, J.W., Chun, H.S., Koo, J.M., Lee, H.J.Jung, S.B.: Microstructural evolution of Sn-rich Au-Sn/Ni flip-chip solder joints under high temperature storage testing conditions. Scripta Mater. 56, 661 2007Google Scholar
15Yoon, J.W.Jung, S.B.: (unpublished paper)Google Scholar
16Kuang, J.H., Sheen, M.T., Chang, C.F.H., Chen, C.C., Wang, G.L.Cheng, W.H.: Effect of temperature cycling on joint strength of PbSn and AuSn solders in laser packages. IEEE Trans. Advan. Packag. 24, 563 2001Google Scholar
17Kim, J., Kim, D.Lee, C.C.: Fluxless flip-chip solder joint fabrication using electroplated Sn-rich Sn-Au structures. IEEE Trans. Advan. Packag. 29, 473 2006Google Scholar
18Kim, J.Lee, C.C.: Fluxless wafer bonding with Sn-rich Sn-Au dual-layer structure. Mater. Sci. Eng., A 417, 143 2006Google Scholar
19Song, H.G., Morris, J.W. Jr.McCormack, M.T.: The microstructure of ultrafine eutectic Au-Sn solder joints on Cu. J. Electron. Mater. 29, 1038 2000Google Scholar
20Yoon, J.W.Jung, S.B.: Interfacial reactions and shear strength on Cu and electrolytic Au/Ni metallization with Sn-Zn solder. J. Mater. Res. 21, 1590 2006Google Scholar
21Zakel, E.Reichl, H.: Au-Sn bonding metallurgy of TAB contacts and its influence on the kirkendall effect in the ternary Cu-Au-Sn. IEEE Trans. Comp., Hybrids. Manuf. Technol. 16, 323 1993Google Scholar
22Kallmayer, C., Jung, E., Kasulke, P., Azadeh, R., Azdasht, G., Zakel, E.Reichl, H.: A new approach to chip size package using meniscus soldering and FPC-bonding. IEEE Trans. Comp., Packag. Manuf. Technol. Part C 21, 51 1998CrossRefGoogle Scholar
23Baggerman, A.F.J.Batenburg, M.J.: Reliable Au-Sn flip-chip bonding on flexible prints. IEEE Trans. Comp., Packag. Manuf. Technol. Part B 18, 257 1995Google Scholar
24Song, H.G., Ahn, J.P., Morris, J.W. Jr.: The microstructure of eutectic Au-Sn solder bumps on Cu/electroless Ni/Au. J. Electron. Mater. 30, 1083 2001CrossRefGoogle Scholar
25Zakel, E.: Ph.D. Thesis, Technical University, Berlin, Germany, 1994Google Scholar
26Massalski, T.B.: Binary Alloy Phase Diagrams ASM International Materials Park, OH 1990 358Google Scholar