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Effect of Cu content on the mechanical reliability of Ni/Sn–3.5Ag system

Published online by Cambridge University Press:  03 March 2011

J.Y. Kim ,
Y.C. Sohn  and
Jin Yu
J.Y. Kim*
Affiliation:
Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Yuseong-gu, Daejeon 305-701, Korea
Y.C. Sohn
Affiliation:
Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Yuseong-gu, Daejeon 305-701, Korea
Jin Yu
Affiliation:
Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Yuseong-gu, Daejeon 305-701, Korea
*
a) Address all correspondence to this author. e-mail: max2020@kaist.ac.kr
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Abstract

Copper was supplied to Sn–3.5Ag by electroplating Cu/Ni double under-bump metallization (UBM), and the amount of Cu was controlled by varying the Cu UBM thickness. Supposed Cu contents in the solder were; 0.2, 0.5, and 1.0 wt%, respectively, and the solder joint microstructure was investigated after 1, 5, and 10 reflows. In the case of specimens with 0.2 and 1.0 wt% Cu, only one type of intermetallic compound (IMC) formed, either (Cu,Ni)6Sn5 or (Ni,Cu)3Sn4, while two types formed in specimen with 0.5 wt% Cu. No correlation could be found between the solder joint microstructure and the ball shear test. However, drop test results showed two opposite trends. The drop resistance of 0.2 and 1.0 wt% Cu specimens was quite good initially but degraded dramatically with multiple reflows, in contrast to that of the 0.5 wt% Cu specimen, which was very poor after one reflow but improved substantially later on. The former was ascribed to thickening of IMC during reflow, while the latter was related to (Ni,Cu)3Sn4 thickening beneath (Cu,Ni)6Sn5 and subsequent spalling of (Cu,Ni)6Sn5 from (Ni,Cu)3Sn4.

Keywords

KineticsMetalMicrostructure
Type
Articles
Information
Journal of Materials Research , Volume 22 , Issue 3 , March 2007 , pp. 770 - 776
Copyright
Copyright © Materials Research Society 2007

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References

REFERENCES

1Zeng, K. and Tu, K.N.: Six cases of reliability study of Pb-free solder joints in electronic packaging technology. Mater. Sci. Eng., R 38, 1 (2002).CrossRefGoogle Scholar
2Laurila, T., Vuorinen, V., and Kivilahti, J.K.: Interfacial reactions between lead-free solders and common base materials. Mater. Sci. Eng., R 49, 1 (2005).Google Scholar
3Wang, C.H. and Chen, S.W.: Sn-0.7 wt%Cu/Ni interfacial reactions at 250 °C. Acta Mater. 54, 247 (2006).Google Scholar
4Bader, S., Gust, W., and Hieber, H.: Rapid formation of intermetallic compounds by interdiffusion in the Cu-Sn and Ni-Sn systems. Acta Mater. 43, 329 (1995).Google Scholar
5Choi, W.K., Kim, J.H., Lee, S.W., and Lee, H.M.: Interfacial microstructure and joint strength of Sn-3.5 Ag-X (X = Cu, In, Ni) solder joint. J. Mater. Res. 17, 43 (2002).Google Scholar
6Li, M., Zhang, F., Chen, W.T., Zeng, K., Tu, K.N., Balkan, H., and Elenius, P.: Interfacial microstructure evolution between eutectic SnAgCu solder and Al/Ni(V)/Cu thin films. J. Mater. Res. 17, 1612 (2002).CrossRefGoogle Scholar
7Gur, D. and Bamberger, M.: Reactive isothermal solidification in the Ni-Sn system. Acta Mater. 46, 4917 (1998).CrossRefGoogle Scholar
8Alam, M.O., Chan, Y.C., and Tu, K.N.: Effect of 0.5 wt% Cu addition in Sn-3.5%Ag solder on the dissolution rate of Cu metallization. J. Appl. Phys. 94, 7904 (2003).CrossRefGoogle Scholar
9Ha, J.S., Oh, T.S., and Tu, K.N.: Effect of supersaturation of Cu on reaction and intermetallic compound formation between Sn–Cu solder and thin film metallization. J. Mater. Res. 18, 2109 (2003).Google Scholar
10Huang, M.L., Loeher, T., Ostmann, A., and Reichl, H.: Role of Cu in dissolution kinetics of Cu metallization in molten Sn-based solders. Appl. Phys. Lett. 86, 181908 (2005).CrossRefGoogle Scholar
11Chen, W.T., Ho, C.E., and Kao, C.R.: Effect of Cu concentration on the interfacial reactions between Ni and Sn-Cu solders. J. Mater. Res. 17, 263 (2002).CrossRefGoogle Scholar
12Ho, C.E., Tsai, R.Y., Lin, Y.L., and Kao, C.R.: Effect of Cu concentration on the reactions between Sn-Ag-Cu solders and Ni. J. Electron. Mater. 31, 584 (2002).CrossRefGoogle Scholar
13Alam, M.O., Chan, Y.C., and Tu, K.N.: Effect of 0.5 wt% Cu in Sn-3.5%Ag solder on the interfacial reaction with Au/Ni metallization. Chem. Mater. 15, 4340 (2003).Google Scholar
14Ho, C.E., Lin, Y.W., Yang, S.C., Kao, C.R., and Jiang, D.S.: Effects of limited Cu supplied on soldering reactions between SnAgCu and Ni. J. Electron. Mater. 35, 1017 (2006).CrossRefGoogle Scholar
15Ho, C.E., Yang, S.C., and Kao, C.R.: Interfacial reaction issues for lead-free electronic solders. J. Mater. Sci.: Mater. Electron. DOI 10.1007/s10854-006-9031-5 (2006).Google Scholar
16Stepniak, F.: Conversion of the under bump metallurgy into intermetallics: The impact on flip chip reliability. Microelectron. Reliab. 41, 735 (2001).CrossRefGoogle Scholar
17Yoon, J.W., Kim, S.W., and Jung, S.B.: IMC morphology, interfacial reaction and joint reliability of Pb-free Sn-Ag-Cu solder on electrolytic Ni BGA substrate. J. Alloys Compd. 392, 247 (2005).CrossRefGoogle Scholar
18Jeon, Y.D., Paik, K.W., Ostmann, A., and Reich, H.: Effects of Cu contents in Pb-free solder alloys on interfacial reactions and bump reliability of Pb-free solder bumps on electroless Ni-P under-bump metallurgy. J. Electron. Mater. 34, 80 (2005).CrossRefGoogle Scholar
19Zhang, F., Li, M., Balakrisnan, B., and Chen, W.T.: Failure mechanism of lead-free solder joints in flip chip packages. J. Electron. Mater. 31, 1256 (2002).CrossRefGoogle Scholar
20 JESD22-B111 JEDEC Standard Board level drop test method of components for handheld electronic products (2003).Google Scholar
21Onishi, M. and Fujibuchi, H.: Reaction diffusion in the Cu-Sn system. Trans. Jpn. Inst. Met. 16, 539 (1975).CrossRefGoogle Scholar
22Oh, M.S.: Growth kinetics of intermetallic phase in the Cu-Sn binary and the Cu-Ni-Sn ternary systems at low temperatures. Doctoral dissertation, Lehigh University, Bethlehem, PA, 1994.Google Scholar
23Sohn, Y.C. and Yu, J.: Correlation between chemical reaction and brittle fracture found in electroless Ni(P)/immersion gold-solder interconnection. J. Mater. Res. 20, 1931 (2005).CrossRefGoogle Scholar
24Chan, Y.C., Tu, P.L., So, A.C.K., and Lai, K.L.: Effect of intermetallic compounds on the shear fatigue of Cu/64Sn-37Pb solder joints. IEEE Trans. Comp. Packag. Manufact. Technol. B 20, 463 (1997).CrossRefGoogle Scholar