J Wang JES 2015.pdf (1.32 MB)
Diffusion barrier characteristics of Ni-NbOx composite electrodeposits for liquid In-Sn solder interconnects
journal contribution
posted on 2015-11-16, 16:29 authored by Jing Wang, Geoffrey Wilcox, Roger J. Mortimer, Changqing Liu, Mark AshworthThe control of interfacial microstructural stability is of utmost importance to the reliability of liquid solder interconnects in high temperature electronic assemblies. This is primarily due to excessive intermetallic compounds (IMCs) that can form and continuously grow during high temperature operation, which renders conventional barrier metallizations inadequate. With the intention of reducing such excessive IMC growth, electrically conducting, NbOx containing Ni coatings were developed using electrodeposition and were assessed as solder diffusion barrier layers in terms of their electrical conductivity and barrier property. The present work adopts a novel electrochemical route to produce Ni-NbOx composite coatings of good uniformity, compactness and purity, from non-aqueous glycol-based electrolytes consisting of NiCl2 and NbCl5 as metal precursors. The effects of cathodic current density and NaBH4 concentrations on the surface morphology, composition and thickness of the coatings were examined. Increased NaBH4 concentrations were found to elevate the maximum deposit thickness (above 10 μm), although these led to a reduction in the co-deposited Nb content. The composite coatings generally exhibited good electrical conductivity. The reaction between a liquid 52In-48Sn solder and Ni-NbOx, with Nb contents up to 6 at.%, was studied at 200°C. The results indicate that, Ni-NbOx with sufficient layer thickness and higher Nb content, offered longer service lifetime. Nb enrichment was generally observed at or close to the reaction front after high temperature storage which suggests evident effectiveness of the enhanced diffusion barrier characteristics. A mechanism for the role of Nb as a barrier performance enhancer was postulated.
History
School
- Science
Department
- Chemistry
Published in
JOURNAL OF THE ELECTROCHEMICAL SOCIETYVolume
162Issue
4Pages
D147 - D153 (7)Citation
WANG, J. ... et al, 2015. Diffusion barrier characteristics of Ni-NbOx composite electrodeposits for Liquid In-Sn solder interconnects. Journal of the Electrochemical Society, 162 (4), pp.D147-D153Publisher
Electrochemical Society Inc (© The Authors 2015)Version
- VoR (Version of Record)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/ by/4.0/Publication date
2015Notes
This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited.ISSN
0013-4651Publisher version
Language
- en