Several authors4-15 describe the deposition and
application of AuSn thin film solder. Aschenbrenner et
al.6 describes a process where the chip pad is metallized
with gold and the substrate is coated with tin. The eutectic
reaction takes place during the die bonding process. z-
phase can be observed on both sides of the joint.
Disadvantage is that layers of brittle intermetallic phases
might be formed and that Kirkendall voids can appear.
often cracks appear directly after the reflow. Shear values
are lower compared to dice bonded with Au80Sn20.
Further, he found a strong degradation of an LED
soldered with the Au10Sn90 eutectic during aging.