Skip to main content Accessibility help
×
Home

Initial interfacial reaction layers formed in Sn–3.5Ag solder/electroless Ni–P plated Cu substrate system

  • Han-Byul Kang (a1), Jae-Wook Lee (a1), Jee-Hwan Bae (a1), Min-Ho Park (a1), Jeong-Won Yoon (a2), Seung-Boo Jung (a2), Jae-Seon Ju (a3) and Cheol-Woong Yang (a1)...

Abstract

Analytical electron microscopy (AEM) was used to examine the initial interfacial reaction layers between a eutectic Sn–3.5Ag solder and an electroless nickel-immersion gold-plated (ENIG) Cu substrate during reflow at 255 °C for 1 s. AEM confirmed that a thick upper (Au,Ni)Sn2 layer and a thin Ni3Sn4 layer had formed through the reaction between the solder and ENIG. The amorphous electroless Ni(P) plated layer transformed into two P-rich Ni layers. One is a crystallized P-rich Ni layer, and the other is an intermediate state P-rich Ni layer before the crystallization. The crystallized P-rich layer consisted of Ni2P and Ni12P5. A thin Ni2P layer had formed underneath the Ni3Sn4 layer and is believed to be a predecessor of the Ni2SnP ternary phase. A Ni12P5 phase was observed beneath the Ni2P thin layer. In addition, nanocrystalline Ni was found to coexist with the amorphous Ni(P) phase in the intermediate state P-rich Ni layer.

Copyright

Corresponding author

a)Address all correspondence to this author. e-mail: cwyang@skku.edu

References

Hide All
1Zeng, K.Tu, K.N.: Six cases of reliability study of Pb-free solder joints in electronic packaging technology. Mater. Sci. Eng., R 38, 55 2002
2Abtew, M.Selvaduray, G.: Lead-free solders in microelectronics. Mater. Sci. Eng., R 27, 95 2000
3Suganuma, K.: Advances in lead-free electronics soldering. Curr. Opin. Solid State Mater. Sci. 5, 55 2001
4Yoon, 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 2006
5Yoon, J.W., Lim, J.H., Lee, H.J., Joo, J., Moon, W.C.Jung, S.B.: Interfacial reactions and joint strength of Sn–37Pb and Sn–3.5Ag solders with immersion Ag-plated Cu substrate during aging at 150 °C. J. Mater. Res. 21, 3196 2006
6Islam, M.N., Chan, Y.C.Sharif, A.: Interfacial reactions of Sn–Cu and Sn–Pb–Ag solder with Au/Ni during extended time reflow in ball grid array packages. J. Mater. Res. 19, 2897 2004
7Wang, C.H.Chen, S.W.: Sn–0.7wt%Cu/Ni interfacial reactions at 250 °C. Acta Mater. 54, 247 2006
8Kim, S.W., Yoon, J.W.Jung, S.B.: Interfacial reactions and shear strengths between Sn–Ag-based Pb-free solder balls and Au/EN/Cu metallization. J. Electron. Mater. 33, 1182 2004
9Jang, J.W., Frear, D.R., Lee, T.Y.Tu, K.N.: Morphology of interfacial reaction between lead-free solders and electroless Ni–P under bump metallization. J. Appl. Phys. 88, 6359 2000
10Wang, S.J.Liu, C.Y.: Retarding growth of Ni3P crystalline layer in Ni(P) substrate by reacting with Cu-bearing Sn(Cu) solders. Scr. Mater. 49, 813 2003
11Lin, Y.C.Duh, J.G.: Phase transformation of the phosphorus-rich layer in SnAgCu/Ni–P solder joints. Scr. Mater. 54, 1661 2006
12Lin, Y.C., Shih, T.Y., Tien, S.K.Duh, J.G.: Suppressing Ni–Sn–P growth in SnAgCu/Ni–P solder joints. Scr. Mater. 56, 49 2007
13Vuorinen, V., Laurila, T., Yu, H.Kivilahti, J.K.: Phase formation between lead-free Sn–Ag–Cu solder and Ni(P)/Au finishes. J. Appl. Phys. 99, 023530 2006
14Lee, C.B., Jung, S.B., Shin, Y.E.Shur, C.C.: Effect of surface finishes on ball shear strength in BGA joints with Sn–3.5 mass% Ag solder. Mater. Trans. 43, 1858 2002
15Alam, M.O., Chan, Y.C.Tu, K.N.: Effect of reaction time and P content on mechanical strength of the interface formed between eutectic Sn–Ag solder and Au/electroless Ni(P)/Cu bond pad. J. Appl. Phys. 94, 4108 2003
16Zeng, K., Vuorinen, V.Kivilahti, J.K.: Interfacial reactions between lead-free SnAgCu solder and Ni(P) surface finish on printed circuit boards. IEEE Trans. Electron. Pack. Manuf. 25, 162 2002
17Jeon, Y.D., Paik, K.W., Bok, K.S., Choi, W.S.Cho, C.L.: Studies of electroless nickel under bump metallurgy—Solder interfacial reactions and their effects on flip chip solder joint reliability. J. Electron. Mater. 31, 520 2002
18Kang, H.B., Bae, J.H., Lee, J.W., Park, M.H., Yoon, J.W., Jung, S.B.Yang, C.W.: Characterization of interfacial reaction layers formed between Sn–3.5Ag solder and electroless Ni-immersion Au-plated Cu substrates. J. Electron. Mater. 37, 84 2008
19Hur, K., Jeong, J.Lee, D.: Microstructures and crystallization of electroless Ni–P deposits. J. Mater. Sci. 25, 2573 1990
20Ma, E., Luo, S.Li, P.: A transmission-electron-microscopy study on the crystallization of amorphous Ni–P electroless deposited coatings. Thin Solid Film 166, 273 1988
21Gao, J., Wu, Y., Liu, L., Shen, B.Hu, W.: Crystallization temperature of amorphous electroless nickel–phosphorus alloys. Mater. Lett. 59, 1665 2005
22Marshall, G.W., Lewis, D.B.Dodds, B.E.: Electroless deposition of Ni–P alloys with and without the use of superimposed pulsed current. Surf. Coat. Technol. 53, 223 1992
23Williams, D.B.Carter, C.B.: Transmission Electron Microscopy Plenum Press New York 1996 351–360
24Szasz, A., Fabian, D.J., Paal, Z.Kojnok, J.: Chemical mechanisms in electroless deposition. J. Non-Cryst. Solids 103, 21 1988

Keywords

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed