ICEPT - An Invetigation into the Effect of Dry Bake on the Solderability Degradation of Electrodeposited Tin Finishes.pdf (1.42 MB)
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An investigation into the effect of dry bake on the solderability degradation of electrodeposited tin finishes

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conference contribution
posted on 30.11.2018, 14:20 authored by Jing Wang, Guang Chen, Henry Forbes, Katerina Christopoulos, Changqing LiuChangqing Liu, Liangquan Sun, Panju Shang
The solderability of component termination finishes degrades upon storage due to the combined effects of surface contamination, oxidation, corrosion and/or intermetallic compound (IMC) formation at the interface between substrate and finishes. Such solderability degradation impinges on the shelf-life of the electronics components and hence demands an in-depth understanding to ensure high reliability Pb-free soldering. This paper is concerned with the effect of the 155°C dry bake precondition on the accelerated ageing of bright Sn electrodeposited termination finishes over Cu substrates. Two coating thicknesses, 2.5 μm and 9 μm, were studied as-received and dry baked for 4 hr and 16 hr as per industrial standards and analysed with respect to their solderability, microstructural and compositional characteristics. It was found that, with increasing dry bake time, both the thickness variations experienced continued solderability degradation, with only the 2.5 μm thick coatings failed after 16 hr of dry heat. Such a loss of solderability was primarily contributed to the exposing of Sn-Cu IMCs. The thickness safety margin (i.e. maximum IMC thickness) for the dry bake condition (16 hr) of the given bright Sn samples was identified to be around 2.5 μm, which could provide a guidance for any future industrial initiative to further reduce coating thickness. Besides, the dry bake conditions have proven to be a consistent and reliable precondition approach for the Sn-based metal finishes

History

School

  • Mechanical, Electrical and Manufacturing Engineering

Published in

2017 18th International Conference of Electronic Packaging Technology (ICEPT)

Citation

WANG, J. ... et al, 2017. An investigation into the effect of dry bake on the solderability degradation of electrodeposited tin finishes. Presented at the 2017 18th International Conference on Electronic Packaging Technology (ICEPT), Harbin, China, 16-19 August 2017, pp.366-371.

Publisher

© IEEE

Version

AM (Accepted Manuscript)

Publication date

2017

Notes

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

ISBN

9781538629727

Language

en

Location

Harbin, China