Abstract
In this paper the tin whisker growth properties of lead-free SAC (SnAgCu) solder alloys were investigated. There different alloys were studied: two micro-alloyed SAC (SnAgCu+Bi+Sb) and the widely applied SAC305 as reference. FR4 test board was developed for 0805 chip resistor components. Solder joints were fabricated on imm-Sn surface finish. The samples were aged in elevated temperature and different humidity levels to induce the tin whisker formation: at 85°C/85RH% and 85°C/20RH%. The test duration was 3000h. Whisker growth was checked after every 500h by scanning electron microscope. The developed whiskers were etched by focused ion beam and the cross-sections were observed by scanning ion microscope and transmission electron microscope. It was shown that the lead-free SAC solder alloys can also develop tin whiskers and the whiskering ability depends on the corrosion behavior of the SAC solders. Copper and bismuth precipitations were found at the whisker roots and within the whiskers which could effect on the number, length and type of the developed whiskers.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
