Abstract
In this study, interfacial reactions between Ni-W alloy films and Sn-3.8Ag-0.7Cu solder have been investigated. Ni-W alloys films with tungsten content in the range of 5.0 – 18.0 at.% was prepared on copper substrate by electrodeposition in ammonia citrate bath. Solder joints were prepared on the Ni-W coated substrate at a reflow temperature of 250 °C. The solder joint interface was investigated by cross-sectional scanning electron microscopy, energy dispersive X-ray spectroscopy and electron back scatter diffraction. It has been observed that a (Cu,Ni) 6 Sn 5 layer formed on the Ni-W alloy film after reflow. The thickness of the (Cu,Ni) 6 Sn 5 layer was found to decrease with the increase of tungsten content in the Ni-W film. An additional layer with a bright appearance was also found to form below the (Cu,Ni) 6 Sn 5 layer. The bright layer was identified to be a ternary phase containing Sn, Cu, W and Ni. The bright layer is found to be amorphous and is suggested to have formed through solid state amorphization caused by anomalously fast diffusion of Sn into Ni-W film.
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: Journal of Materials Science: Materials in Electronics
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.