A micromechanism study of thermosonic gold wire bonding on aluminium pad

A micromechanism of thermosonic gold wire bonding was elaborated by examining its interfacial characteristics as a result of the bonding process, including the fragmentation of the native aluminum oxide layer on Al pads, and formation of initial intermetallic compounds...

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Main Authors: Xu, Hui, Liu, Changqing, Silberschmidt, Vadim V., Pramana, S. S., White, Timothy John, Chen, Z., Sivakumar, M., Acoff, V. L.
Other Authors: School of Materials Science & Engineering
Format: Journal Article
Language:English
Published: 2012
Subjects:
Online Access:https://hdl.handle.net/10356/94156
http://hdl.handle.net/10220/7694
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author Xu, Hui
Liu, Changqing
Silberschmidt, Vadim V.
Pramana, S. S.
White, Timothy John
Chen, Z.
Sivakumar, M.
Acoff, V. L.
author2 School of Materials Science & Engineering
author_facet School of Materials Science & Engineering
Xu, Hui
Liu, Changqing
Silberschmidt, Vadim V.
Pramana, S. S.
White, Timothy John
Chen, Z.
Sivakumar, M.
Acoff, V. L.
author_sort Xu, Hui
collection NTU
description A micromechanism of thermosonic gold wire bonding was elaborated by examining its interfacial characteristics as a result of the bonding process, including the fragmentation of the native aluminum oxide layer on Al pads, and formation of initial intermetallic compounds (IMCs). It is found that the existence of an approximately 5 nm thick native oxide layer on original Al pads has a significant effect on the bonding, and the nucleation of IMCs during the bonding process must overcome this relatively inert thin film. Bonding strength was fundamentally determined by the degree of fragmentation of the oxide films, through which the formation of IMCs can be initiated due to the direct contact of the metal surfaces to be bonded. The extent of fracture the oxide layer was strongly influenced by the level of ultrasonic power, as at its high level alumina fragmentation becomes pervasive resulting in contiguous alloy interfaces and robust bonds. The IMCs formed at the interfaces were identified as Al4Al and AuAl2 with a thickness of 150–300 nm. The formation mechanism of such IMCs was explained by the effective heat of formation theory.
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spelling ntu-10356/941562023-07-14T15:44:59Z A micromechanism study of thermosonic gold wire bonding on aluminium pad Xu, Hui Liu, Changqing Silberschmidt, Vadim V. Pramana, S. S. White, Timothy John Chen, Z. Sivakumar, M. Acoff, V. L. School of Materials Science & Engineering DRNTU::Engineering::Materials A micromechanism of thermosonic gold wire bonding was elaborated by examining its interfacial characteristics as a result of the bonding process, including the fragmentation of the native aluminum oxide layer on Al pads, and formation of initial intermetallic compounds (IMCs). It is found that the existence of an approximately 5 nm thick native oxide layer on original Al pads has a significant effect on the bonding, and the nucleation of IMCs during the bonding process must overcome this relatively inert thin film. Bonding strength was fundamentally determined by the degree of fragmentation of the oxide films, through which the formation of IMCs can be initiated due to the direct contact of the metal surfaces to be bonded. The extent of fracture the oxide layer was strongly influenced by the level of ultrasonic power, as at its high level alumina fragmentation becomes pervasive resulting in contiguous alloy interfaces and robust bonds. The IMCs formed at the interfaces were identified as Al4Al and AuAl2 with a thickness of 150–300 nm. The formation mechanism of such IMCs was explained by the effective heat of formation theory. Published version 2012-04-09T03:46:41Z 2019-12-06T18:51:42Z 2012-04-09T03:46:41Z 2019-12-06T18:51:42Z 2010 2010 Journal Article Xu, H., Liu, C., Silberschmidt, V. V., Pramana, S. S., White, T. J., Chen, Z., et al. (2010). A micromechanism study of thermosonic gold wire bonding on aluminium pad. Journal of applied physics, 108(11). https://hdl.handle.net/10356/94156 http://hdl.handle.net/10220/7694 10.1063/1.3514005 en Journal of applied physics © 2010 American Institute of Physics. This paper was published in Journal of Applied Physics and is made available as an electronic reprint (preprint) with permission of American Institute of Physics. The paper can be found at the following DOI: http://dx.doi.org/10.1063/1.3514005. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law. 8 p. application/pdf
spellingShingle DRNTU::Engineering::Materials
Xu, Hui
Liu, Changqing
Silberschmidt, Vadim V.
Pramana, S. S.
White, Timothy John
Chen, Z.
Sivakumar, M.
Acoff, V. L.
A micromechanism study of thermosonic gold wire bonding on aluminium pad
title A micromechanism study of thermosonic gold wire bonding on aluminium pad
title_full A micromechanism study of thermosonic gold wire bonding on aluminium pad
title_fullStr A micromechanism study of thermosonic gold wire bonding on aluminium pad
title_full_unstemmed A micromechanism study of thermosonic gold wire bonding on aluminium pad
title_short A micromechanism study of thermosonic gold wire bonding on aluminium pad
title_sort micromechanism study of thermosonic gold wire bonding on aluminium pad
topic DRNTU::Engineering::Materials
url https://hdl.handle.net/10356/94156
http://hdl.handle.net/10220/7694
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