Thermal reliabilities of Sn-0.5Ag-0.7Cu-0.1Al2O3/Cu solder joint
(1. College of Integrated Circuit Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210003, China;
2. Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-Sen University, Zhuhai 519082, China;
3. College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
4. School of Materials Science and Engineering, Nanjing University of Science & Technology, Nanjing 210016, China)
2. Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-Sen University, Zhuhai 519082, China;
3. College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
4. School of Materials Science and Engineering, Nanjing University of Science & Technology, Nanjing 210016, China)
Abstract: The effects of trace addition of Al2O3 nanoparticles (NPs) on thermal reliabilities of Sn-0.5Ag-0.7Cu/Cu solder joints were investigated. Experimental results showed that trace addition of Al2O3 NPs could increase the isotheraml aging (IA) and thermal cyclic (TC) lifetimes of Sn-0.5Ag-0.7Cu/Cu joint from 662 to 787 h, and from 1597 to 1824 cycles, respectively. Also, trace addition of Al2O3 NPs could slow down the shear force reduction of solder joint during thermal services, which was attributed to the pinning effect of Al2O3 NPs on hindering the growth of grains and interfacial intermetallic compounds (IMCs). Theoretically, the growth coefficients of interfacial IMCs in IA process were calculated to be decreased from 1.61×10-10 to 0.79×10-10 cm2/h in IA process, and from 0.92×10-10 to 0.53×10-10 cm2/h in TC process. This indicated that trace addition of Al2O3 NPs can improve both IA and TC reliabilities of Sn-0.5Ag- 0.7Cu/Cu joint, and a little more obvious in IA reliability.
Key words: Sn-0.5Ag-0.7Cu solder; Al2O3 nanoparticles; isothermal aging; thermal cycling; thermal reliability