Abstract
The creep properties of Lead-free solder joints were evaluated by Shear Punch (SP) method. Lead-free solder joints with Sn-4Ag, Sn-4Ag-0.5Cu and Sn-4Ag-1.0Cu solder tested and compared to the lead solder joint with Sn-37Pb. SP creep tests were performed at temperature of 30, 50 and 80°C. For the SP method, constant shear stresses from 3 to 22 MPa were applied into the SP specimen(10 × 10 × 0.5 mm). From the SEM, IMC layer of Cu6Sn5 were observed on the interface between solder and Cu. From the SEM and EDX, the Lead-free solder joints have much thicker interfacial IMC layer than the Sn-37Pb solder joint. From the power law relationships, the Lead-free solder joints show superior creep resistance than the Sn-37Pb solder joint. And among Lead-free solder joints, at 30 and 50°C, the ternary SnAgCu solder joints have high creep resistance than the binary SnAg solder joint. Sn-4Ag-1.0Cu solder joint shows the best creep resistance at 30°C, and Sn-4Ag-0.5Cu solder joint shows the best creep resistance at 50°C. However, at high temperature 80°C, all of the Lead-free solder joints have similar creep properties. The activation energy were expressed with creep strain rate and temperature. The ternary SnAgCu solder joints have the higher activation energy than the binary SnAg solder joint at 17.68 and 18.72 MPa. Average activation energy of Lead-free solder joints were lower than that of Sn-37Pb 75.11 kJ/mol. The average activation energy of Sn-4Ag-1.0Cu, Sn-4Ag-0.5Cu and Sn-4Ag solder joint at high stress is 102.68, 62.52 and 58.61 kJ/mol, respectively.
Similar content being viewed by others
References
Abtew, M. and Selvaduray, G. (2000). Lead-free solders in microelec-tronics. Materials Science and Engineering, 27, 95–141.
Alizadeh, R., Mahmudi, R. and Esfandyarpour, M. J. (2011). Shear punch creep test: A novel localized method for evaluating creep properties. Scripta Materialia, 64, 442–445.
Deng, X., Sidhu, R. S., Johnson, P. and Chawla, N. (2005). Influence of reflow and thermal aging on the shear strength and fracture behavior of Sn-3.5Ag solder/Cu joints. Metallurgical and Materials Transactions, 36A, 55–64.
Felton, L. E., Rajan, K., Ficalora, P. J. and Singh, P. (1991). n-Cu6Sn5 precipitates in Cu/PbSn solder joints. Scripta Metallurgica et Materialia, 25, 2329–2333.
Joo, D. K., Yu, J. and Shin, S. W. (2003). Creep rupture of lead-free Sn-3.5Ag-Cu solders. J. Electronic Materials 32, 6, 541–547.
Kerr, M. and Chawla, N. (2004). Creep behavior of Sn-3.5Ag solder/Cu couple at small length scales. ACTA Materialia, 52, 4527–4535.
Lin, C. K. and Chu, D. Y. (2005). Creep rupture of leadfree Sn-3.5Ag and Sn-3.5Ag-0.5Cu solders. J. Materials Science: Materials in Electronics, 16, 355–365.
Shi, Y. W., Yan, Y. F., Liu, J. P., Xia, Z. D., Lei, Y. P., Guo, F. and Li, X. Y. (2010). Constitutive modeling on creep for a SnPb-based composite solder reinforced with microsized Cu particles. Microelectronics Reliability, 50, 2020–2025.
Sidhu, R. S. and Chawla, N. (2008). Microstructure characterization and creep behavior of Pb-free Sn-rich solder alloys: Part I. Microstructure characterization of bulk solder and solder/copper joints. Metallurgical and Materials Trans., 39A, 340–348.
Sidhu, R. S., Deng, X. and Chawla, N. (2008). Microstructure characterization and creep behavior of Pb-free Sn-rich solder alloys: Part II. Creep behavior of bulk solder and solder/copper joints. Metallurgical and Materials Trans., 39, 349–362.
Wiese, S. and Wolter, K. J. (2007). Creep of thermally aged SnAgCu-solder joints. Microelectronics Reliability, 47, 223–232.
Wiese, S., Feustel, F. and Meusel, E. (2002). Characterisation of constitutive behavior of SnAg, SnAgCu and SnPb solder in flip chip joints. Sensors and Actuators, 99, 188–193.
Xiao, L., Liu, J., Lai, Z. and Ye, L. (2000). A. Thölen, characterization of mechanical properties of buck leadfree solders. Proc. Int. Symp. Advanced Packaging Materials. Braselton, GA., 6–8, 145–151.
Yu, D. Q., Wang, L., Wu, C. M. L. and Law, C. M. T. (2005). The formation of nano-Ag3Sn particles on the intermetallic compounds during wetting reaction. J. Alloys and Compounds, 389, 153–158.
Yu, D. Q., Wu, C. M. L., Law, C. M. T., Wang, L. and Lai, J. K. L. (2005). Intermetallic compounds growth between Sn-3.5Ag lead-free solder and Cu substrate by dipping method. J. Alloys and Compounds, 392, 192–199.
Zhang, X. P., Yu, C. B., Zhang, Y. P., Shrestha, S. and Dorn, L. (2007). Processing treatment of a lead-free Sn-Ag-Cu-Bi solder by rapid laser-beam reflowing and the creep property of its soldered connection. J. Materials Processing Technology, 192–193, 539–542.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Yang, Z.J., Yang, S.M., Yu, H.S. et al. IMC and creep behavior in Lead-free solder joints of Sn-Ag and Sn-Ag-Cu alloy system by SP method. Int.J Automot. Technol. 15, 1137–1142 (2014). https://doi.org/10.1007/s12239-014-0118-3
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12239-014-0118-3