Interfacial Reactions in Ni-doped SAC105 and SAC405 Solders on Ni-Au Finish during Multiple Reflows
Solder-joint performances for SAC405, SAC 105 with 200ppm Ni and SAC105 with 500ppm Ni were reviewed for electrolytic NiAu BGA pad finish. For each alloy system, ball shear tests, cross-sectional analysis and 3-D etching were performed to study the interfacial reactions after repeated reflows. Also, the effect of solder-mask pad design on solder joint integrity was investigated. In this study, all three systems gave rise to only (Cu,Ni)6Sn5 IMC layer at the soldering interface after multiple reflows at 245℃. The (Cu,Ni)6Sn5 IMC had a needle-shaped structure after 1 time of reflow and the morphology remained the same after multiple retlows.SACN0.05 appeared to be inappropriate for a BGA pad finish. It exhibited a drastic increase in the IMC layer thickness after 11times of reflow and this corresponded to a significant increase in IMC fracture mode percentage. NSMD pad design led to ball pad lifting because the bonding between the pad and substrate was weaker than the bulk solder strength and the IMC-pad interface bonding.
Toh C.H. Liu Hao Tu C.T Chen T.D. Jessica Yeo
United Test and Assembly Center Ltd, 5 Serangoon North Ave 5, SINGAPORE 554916 Accurus Scientific Co., Ltd, 508-51, Wen Sien Road, Section 1 Jen-Der, Tainan, TAIWAN
国际会议
第八届电子封装技术国际会议(2007 8th International Conference on Electronics Packaging Technology ICEPT2007)
上海
英文
410-415
2007-08-14（万方平台首次上网日期，不代表论文的发表时间）