Abstract
Entrapment of volatiles during lead-free solder joint formation results in the creation of voids which may have a negative impact on the joint's mechanical and/or electrical performances. According to IPC-J-STD-001E and IPC-A-610E specifications, the post-surface-mount-technology cumulative voiding criterion in lead-free solder joints is less than 25% for a second-level interconnect. For solder joints that experience multiple high-temperature reflow processes after completion of assembly, however, it is important to understand and predict how these voids will interact and evolve during subsequent high-temperature exposures. In this paper, both in situ 2-D X-ray imaging and 3-D X-ray tomography were used to study the growth kinetics of solder joint voids during multiple reflow cycles. The results demonstrate that voids grow and move during each reflow cycle. The growth kinetics has been shown to follow a diffusion-controlled mechanism based on a model for out-gassing bubble growth in a supersaturated molten solder liquid.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: IEEE Transactions on Device and Materials Reliability
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.