title: Interfacial Reaction Characteristics of Au Stud/Sn/Cu Pillar Bump During Annealing and Current Stressing.
abstract: In this work, intermetallic compound (IMC) growth behavior in Au stud/Sn/Cu pillar bumps was investigated under annealing and current stressing conditions. AuSn2 and AuSn4 IMCs formed at the interface between the Au studs and Sn after bonding. The AuSn2 phase grew significantly as the stressing time increased, causing micro-voids to form near the (Cu, Au)6Sn5, AuSn2 and AuSn4 IMC interfaces. The interfacial reactions resulting from current stressing took place quicker than observed for pure annealing. The apparent activation energies for the growth of the AuSn2 phase during annealing and current stressing were 0.52 eV and 0.47 eV, respectively, which may be closely related to the acceleration of the interfacial reaction by electron wind forces during current stressing.
authors.forename: Jun-Beom
authors.initials: JB
authors.lastname: Kim
authors.forename: Byeong-Rok
authors.initials: BR
authors.lastname: Lee
authors.forename: Sung-Hyuk
authors.initials: SH
authors.lastname: Kim
authors.forename: Jong-Myeong
authors.initials: JM
authors.lastname: Park
authors.forename: Young-Bae
authors.initials: YB
authors.lastname: Park