TY - GEN
T1 - Evolution of AuSnx intermetallic components in laser reflowed right-angled solder joints during isothermal aging process
AU - Liu, Wei
AU - Wang, Chunqing
AU - Tian, Yanhong
AU - Li, Mingyu
PY - 2007
Y1 - 2007
N2 - Au surface finish is common used as a protection layer on pads. In the traditional reflow process, Au will be dissolved into solder and form AuSn 4 IMCs (intermetallic components). However, as for the solder joints fabricated by laser soldering, the morphology and distribution of the AuSn x IMCs are quite different from that in solder joints fabricated by traditional reflow methods. The formation, distribution and evolution of IMCs will affect the property and reliability of solder joints directly. This paper presents a detailed analysis of AuSnx IMCs evolution in laser reflowed solder joints during isothermal aging process. To investigate the effect of Au thickness on the evolution of AuSnx IMCs, pads with 0.1, 0.5, 0.9 or 4.0 μmAu surface finish were introduced into our experiment. The solder joints were aged in the 125°C isothermal oven. Experiment results showed that few IMCs formed at the interface of the solder and the pad with 0.1μm Au surface finish. Even in the condition of 31 days aging, the thickness of IMCs didn't increase a lot; as for the laser reflowed solder joints with 0.5 or 0.9μm Au surface finish on the pad, most of the AuSn4 IMCs stayed at the interface and formed in needle-like or dendritic morphology. With the increase of aging time, the AuSn4 IMCs became more flat and changed to a continuous layer; In the laser reflowed solder joints with 4.0μm Au surface finish on the pad, AuSn, AuSn2, AuSn4 IMCs and Au2Sn phase formed at the interface. With the increase of aging time, more Sn rich IMCs formed at the interface, and evolved to AuSn 4 IMCs in the condition of long time aging. The thickness of AuSn4 IMCs can reach about 30μm.
AB - Au surface finish is common used as a protection layer on pads. In the traditional reflow process, Au will be dissolved into solder and form AuSn 4 IMCs (intermetallic components). However, as for the solder joints fabricated by laser soldering, the morphology and distribution of the AuSn x IMCs are quite different from that in solder joints fabricated by traditional reflow methods. The formation, distribution and evolution of IMCs will affect the property and reliability of solder joints directly. This paper presents a detailed analysis of AuSnx IMCs evolution in laser reflowed solder joints during isothermal aging process. To investigate the effect of Au thickness on the evolution of AuSnx IMCs, pads with 0.1, 0.5, 0.9 or 4.0 μmAu surface finish were introduced into our experiment. The solder joints were aged in the 125°C isothermal oven. Experiment results showed that few IMCs formed at the interface of the solder and the pad with 0.1μm Au surface finish. Even in the condition of 31 days aging, the thickness of IMCs didn't increase a lot; as for the laser reflowed solder joints with 0.5 or 0.9μm Au surface finish on the pad, most of the AuSn4 IMCs stayed at the interface and formed in needle-like or dendritic morphology. With the increase of aging time, the AuSn4 IMCs became more flat and changed to a continuous layer; In the laser reflowed solder joints with 4.0μm Au surface finish on the pad, AuSn, AuSn2, AuSn4 IMCs and Au2Sn phase formed at the interface. With the increase of aging time, more Sn rich IMCs formed at the interface, and evolved to AuSn 4 IMCs in the condition of long time aging. The thickness of AuSn4 IMCs can reach about 30μm.
UR - https://www.scopus.com/pages/publications/34948880612
U2 - 10.1109/ICEPT.2006.359868
DO - 10.1109/ICEPT.2006.359868
M3 - 会议稿件
AN - SCOPUS:34948880612
SN - 142440620X
SN - 9781424406203
T3 - 2006 7th International Conference on Electronics Packaging Technology, ICEPT '06
BT - 2006 7th International Conference on Electronics Packaging Technology, ICEPT '06
T2 - 2006 7th International Conference on Electronics Packaging Technology, ICEPT '06
Y2 - 26 August 2006 through 29 August 2006
ER -