|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Electronic Packaging and Interconnections
||Characterising the intermetallic layer in mixed Sn-Bi paste/SAC BGA solder ball joints
||Jiye Zhou, Qichao Hao, Xin Fu Tan, Stuart McDonald, Kazuhiro Nogita
|On-Site Speaker (Planned)
The polymorphic transformation that occurs in the Cu6Sn5 intermetallic compound at 186°C has the potential to generate stresses that could lead to cracking of that phase in soldered joints. This cracking may occur during the multiple reflow cycles of a typical printed board assembly process or during the thermal cycles to which electronic assemblies are exposed during service. In past few years we have demonstrated how manipulating the reflow profile for Sn-Cu and SAC solders on Cu substrates can influence cracking behaviour. In this presentation, the authors investigate crack fromations in Cu6Sn5 in Sn-37Bi and Sn-58Bi solder pastes that are reflowed adjacent to a Cu substrate and SAC solder balls. The influence of peak reflow temperature and cooling conditions on cracking is discussed with respect to the solder composition.
||Solidification, Joining, Other