Loughborough University
Browse
1-s2.0-S0026271422001780-main.pdf (2.98 MB)

Investigation of thermal effect on solidification in Sn/Cu interconnects during self-propagating exothermic reaction bonding

Download (2.98 MB)
journal contribution
posted on 2022-11-04, 14:08 authored by Shuibao Liang, Yi Zhong, Stuart RobertsonStuart Robertson, Allan Liu, Han Jiang, Canyu Liu, Zhaoxia ZhouZhaoxia Zhou, Changqing Liu
Self-propagating exothermic reaction (SPER) of alternating metal nanolayers provides intense localised heat that allows bonding of metals or alloys under ambient temperature. However, the formation of the bonds through the rapid heating and cooling confined at the bonding interfaces is a non-equilibrium process, and the thermal effect on solidification and manufacturing reliability is yet to be understood. In this work, the Cu/Sn-nanofoil-Sn/Cu interconnects (where Sn is a solder layer) prepared via SPER of Ni/Al nanofoil are studied by numerical simulations and experiments to understand the thermal transfer and its effect on the solidification. It has been found that the SPER completes within a few milliseconds, the temperature at solder/Cu interface can be higher than the melting point of solder, and the cooling rate can be as high as 1.5 × 107 ◦C/s, the maximum temperature gradient can reach 5.40 × 107 ◦C/m. The microstructure predicted by simulation agrees well to the experimental results: the columnar dendrites are formed in the solder during the cooling stage, and the columnar structures prefer to form and grow in the solder region due to the high cooling rate.

Funding

(EPSRC) Heterogeneous integration to enable manufacture and assembly of power electronics : EP/R004501/1

Quasi-ambient bonding to enable cost-effective high temperature Pb-free solder interconnects : EP/R032203/1

History

School

  • Mechanical, Electrical and Manufacturing Engineering

Published in

Microelectronics Reliability

Volume

138

Publisher

Elsevier BV

Version

  • VoR (Version of Record)

Rights holder

© 2022 The Authors

Publisher statement

Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

Acceptance date

2022-07-14

Publication date

2022-09-25

Copyright date

2022

ISSN

0026-2714

Language

  • en

Depositor

Deposit date: 4 November 2022

Article number

114654

Usage metrics

    Loughborough Publications

    Categories

    No categories selected

    Licence

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC