TY - JOUR
T1 - Effect of Au/Pd bilayer metallization on solder/Cu interfacial reaction and growth kinetics of Cu[sbnd]Sn intermetallic compounds during solid-state aging
AU - Liang, Chien Lung
AU - Lin, Kwang Lung
AU - Cheng, Po Jen
N1 - Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2017/6/15
Y1 - 2017/6/15
N2 - The present study investigated the effect of Au/Pd bilayer metallization, 0.46 μm Au and 0.04 μm Pd, on the solder/Cu interfacial reaction and growth kinetics of the Cu[sbnd]Sn intermetallic compounds during solid-state aging. The as-reflowed Ni/Sn1.8Ag + Sn3Ag0.5Cu/Au/Pd/Cu solder joint was aged at 150 °C for 500 and 1000 h. The solder joint incorporated with bare Cu pad was also investigated for comparison. The interfacial reaction between solder and Au/Pd metallized Cu pad formed the (Cu,Ni,Pd,Au)6Sn5 and Cu3Sn compounds during reflow. The AuSn4 compound was distributed throughout the solder joint. The AuSn4 compound gradually dissolved during thermal aging, which rendered Au incorporate with Cu6Sn5 for up to 6.58–8.61 at.%. The substantial inclusion of Au in the Cu6Sn5 stabilized the compound and accelerated the compound growth during solid-state aging. The fast growing Cu6Sn5 strongly suppressed the formation of the neighboring Cu3Sn compound and thus effectively suppressed the potential micro-void formation within the Cu3Sn layer. Additionally, the formation of the undesirable AuSn4 compound was inhibited in the solder joint incorporated with Au/Pd metallized Cu pad. These observations are expected to enhance the functional performance of the solder joint with the incorporation of Au/Pd metallization at the solder/Cu interface.
AB - The present study investigated the effect of Au/Pd bilayer metallization, 0.46 μm Au and 0.04 μm Pd, on the solder/Cu interfacial reaction and growth kinetics of the Cu[sbnd]Sn intermetallic compounds during solid-state aging. The as-reflowed Ni/Sn1.8Ag + Sn3Ag0.5Cu/Au/Pd/Cu solder joint was aged at 150 °C for 500 and 1000 h. The solder joint incorporated with bare Cu pad was also investigated for comparison. The interfacial reaction between solder and Au/Pd metallized Cu pad formed the (Cu,Ni,Pd,Au)6Sn5 and Cu3Sn compounds during reflow. The AuSn4 compound was distributed throughout the solder joint. The AuSn4 compound gradually dissolved during thermal aging, which rendered Au incorporate with Cu6Sn5 for up to 6.58–8.61 at.%. The substantial inclusion of Au in the Cu6Sn5 stabilized the compound and accelerated the compound growth during solid-state aging. The fast growing Cu6Sn5 strongly suppressed the formation of the neighboring Cu3Sn compound and thus effectively suppressed the potential micro-void formation within the Cu3Sn layer. Additionally, the formation of the undesirable AuSn4 compound was inhibited in the solder joint incorporated with Au/Pd metallized Cu pad. These observations are expected to enhance the functional performance of the solder joint with the incorporation of Au/Pd metallization at the solder/Cu interface.
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U2 - 10.1016/j.surfcoat.2017.03.033
DO - 10.1016/j.surfcoat.2017.03.033
M3 - Article
AN - SCOPUS:85016545669
SN - 0257-8972
VL - 319
SP - 55
EP - 60
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
ER -