|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Advanced Microelectronic Packaging, Emerging Interconnection Technology, and Pb-free Solder
||In-situ high-voltage TEM Observations of Polymorphic Phase Transformations in Cu6Sn5 Solder Joints
||Flora Somidin, Hiroshi Maeno, Mohd Arif Anuar Mohd Salleh, Xuan Quy Tran, Stuart David McDonald, Syo Matsumura, Kazuhiro Nogita
|On-Site Speaker (Planned)
The polymorphic transformation of Cu6Sn5 has the potential to generate internal stresses in soldered joints during both the soldering process and subsequent device operation involving thermal cycling. To understand the mechanism of the polymorphic transformation and associated stress accumulation/release in solder joints, Cu6Sn5 was studied using ultra high-voltage Transmission Electron Microscopy (UHV-TEM) equipped with an Omega energy filter. In this study, we successfully observed (1) stress accumulation/release, and (2) the kinetics of the phase transformation from hexagonal to monoclinic in solder joint Cu6Sn5 through bright field image videos and a series of selected area diffraction patterns under various thermal conditions. The results of this study help to understand the mechanisms of cracking in solder joint Cu6Sn5 and can be used to construct a time-temperature-transformation (TTT) diagram describing the transformation. The method provides a new approach for the study of phase transformations and complements other widely-used methods including XRD and DSC.
||Planned: Supplemental Proceedings volume