TY - JOUR
T1 - Cross-interaction between au/sn and cu/sn interfacial reactions
AU - Yen, Yee Wen
AU - Tseng, H. W.
AU - Zeng, K.
AU - Wang, S. J.
AU - Liu, C. Y.
N1 - Funding Information:
The authors would like to thank Professor J.G. Duh and Ms. S.Y. Tsai from the Department of Materials Science and Engineering, Nation Tsing Hua University, for their help with the EPMA. The work was financially supported by the National Science Council (NSC), Taiwan.
PY - 2009/11
Y1 - 2009/11
N2 - The cross-interaction between Sn/Cu and Sn/Au interfacial reactions in an Au/Sn/Cu sandwich structure was studied. Field-emission electron probe microanalysis (FE-EPMA) revealed that the Cu content in the three Au-Sn phases (AuSn, AuSn 2, and AuSn 4) was very low, less than 1 at.%. This means that Cu from the opposite Cu foil did not participate in the interfacial reaction at the Sn/Au interface. On the opposite Sn/Cu side, Au-substituted (Cu,Au) 6Sn 5 formed within the initial 1 min of reflow. With prolonged reflow, the Au content in the Au-substituted (Cu,Au) 6Sn 5 increased and it transformed into a Cu-substituted (Au,Cu)Sn phase with 25 at.% Cu after 1 min of reflow at 250°C. The x-ray diffraction (XRD) pattern confirmed the phase transformation of Au-substituted (Cu,Au) 6Sn 5 to Cu-substituted (Au,Cu)Sn phase. In addition, there was greater Au consumption in the Au/Sn/Cu sandwich joint structure than in the single Au/Sn reaction case, due to some of the Au participating in the opposite Sn/Cu interfacial reaction.
AB - The cross-interaction between Sn/Cu and Sn/Au interfacial reactions in an Au/Sn/Cu sandwich structure was studied. Field-emission electron probe microanalysis (FE-EPMA) revealed that the Cu content in the three Au-Sn phases (AuSn, AuSn 2, and AuSn 4) was very low, less than 1 at.%. This means that Cu from the opposite Cu foil did not participate in the interfacial reaction at the Sn/Au interface. On the opposite Sn/Cu side, Au-substituted (Cu,Au) 6Sn 5 formed within the initial 1 min of reflow. With prolonged reflow, the Au content in the Au-substituted (Cu,Au) 6Sn 5 increased and it transformed into a Cu-substituted (Au,Cu)Sn phase with 25 at.% Cu after 1 min of reflow at 250°C. The x-ray diffraction (XRD) pattern confirmed the phase transformation of Au-substituted (Cu,Au) 6Sn 5 to Cu-substituted (Au,Cu)Sn phase. In addition, there was greater Au consumption in the Au/Sn/Cu sandwich joint structure than in the single Au/Sn reaction case, due to some of the Au participating in the opposite Sn/Cu interfacial reaction.
KW - AuSn
KW - Cross-interaction
KW - Flip-chip technology
UR - http://www.scopus.com/inward/record.url?scp=70349856158&partnerID=8YFLogxK
U2 - 10.1007/s11664-009-0920-2
DO - 10.1007/s11664-009-0920-2
M3 - 期刊論文
AN - SCOPUS:70349856158
VL - 38
SP - 2257
EP - 2263
JO - Journal of Electronic Materials
JF - Journal of Electronic Materials
SN - 0361-5235
IS - 11
ER -