Effect of nano Al2O3 particles doping on electromigration and mechanical properties of Sn–58Bi solder joints

• Published in: Microelectronics and reliability Vol. 55; no. 8; pp. 1226 - 1233
• Main Authors: Hu, Tianwei, Li, Yi, Chan, Yan-Cheong, Wu, Fengshun
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2015
• Subjects: Al2O3 nanoparticle; Electromigration; Nano-doping; Sn–58Bi solder; Electromigration; Sn–58Bi solder; Al2O3 nanoparticle; Nano-doping
• ISSN: 0026-2714; 1872-941X
• DOI: 10.1016/j.microrel.2015.05.008

•The intermetallic compounds (IMC) of the doped solder (Al2O3) reduced at 85°C.•The IMC layer of doped solder decreased under current density 5000A/cm2 at 85°C.•The doped solder exhibited good performances in microhardness and shear strength.•The fracture surface of doped solder showed a typical rough and ductile structure. In the present study, the effect of Al2O3 nanoparticles on performances of Sn–58Bi solder were investigated in aspects of electro-migratio, shear strength and microhardness. The experimental results show that the Al2O3 nanoparticles significantly improved microstructure and mechanical performances of solder joints. With the addition of 0.5wt% Al2O3, the intermetallic compounds (IMC) reduced from 2.5μm to 1.27μm after 288 aging hours at 85°C. Furthermore, after electromigration test under a current density of 5×103 A/cm2 at 85°C, Bi-rich layers formed at the anode side of both Al2O3 doped and plain solder. Moreover, the addition of Al2O3 nanoparticles reduced the mean thickness of Bi-rich layer. In addition, the growth rate of the IMC layer of Al2O3 doped solder decreased by 8% compared with the plain solder. Besides, the Al2O3 doped solder exhibited better performance than plain solder in microhardness after different aging times. While, the addition of Al2O3 significantly impeded the degradation of the shear strength of solder joint after aging for 48 and 288h. Furthermore, it was worth noting that the fracture surface of doped solder showed a typical rough and ductile structure. However, plain solder exhibited a relatively smooth and fragile surface.