Title :
Effect of Cu on interfacial reaction in high-lead solder bumps
Author :
Xu, Liwei ; Huang, Mingliang ; Yao, Quanbin ; Wang, Yong ; Lian, Binhao
Author_Institution :
Laboratory of Electronic Packaging Materials, School of Materials Science&Engineering, Dalian University of Technology, 116024, China
Abstract :
The formation of interfacial intermetallic compound (IMC) and the mechanical properties of 95Pb-5Sn, 90Pb-10Sn and 85Pb-13Sn-2Cu (in wt.%) flip-chip solder joint with the Ti/Cu/Cu under bump metallization (UBM) after single and three times reflows were investigated. After reflow soldering, Cu3Sn IMC formed on the Cu under bump metallurgy (UBM) for all of the solder alloys. The thickness of the Cu3Sn IMC layers increased with increasing reflow times. The average IMC grain size of 85Pb-13Sn-2Cu/Cu was larger than those of 90Pb-10Sn/Cu and 95Pb-5Sn/Cu after same times reflows. Ball shear tests were carried out to evaluate the UBM solderability and the bonding quality of solder bumps after single reflow and three times reflows. The shear strength of 85Pb-13Sn-2Cu/Cu is higher than that of 90Pb-10Sn/Cu and 95Pb-5Sn/Cu after both one and three times reflows. The shear curves show that the solder joints occured significant plastic deformation and behaves a “ductile” fracture for all of the three solders.
Keywords :
Annealing; Flip-chip devices; Packaging; Reliability; Soldering; Interfacial reaction; Intermetallic compound; Mechanical property; Sn-Pb-Cu; Solder bump;
Conference_Titel :
Electronic Packaging Technology (ICEPT), 2015 16th International Conference on
Conference_Location :
Changsha, China
DOI :
10.1109/ICEPT.2015.7236813
