---
_id: '9870'
abstract:
- lang: eng
  text: Nowadays wire bonding is a widely-used technology for interconnecting chips
    in the packaging industry. Thereby, it is known that the bond quality massively
    depends upon the microstructure prevailing in the bond and consequently the materials
    used as well as the bonding parameters. However the actually used materials such
    as aluminum and gold are either characterized by comparibly poor conductivity
    or high costs, respectively. Due to its outstanding properties copper is a more
    attractive candidate. Still, a thorough investigation on the interrelationship
    between the material combinations, the processing parameters and the resulting
    microstructure for copper and aluminum wire bonding was not carried out yet. Depending
    on the aforementioned factors the microstructural evolution can be completely
    different during the bonding process. Therefore, this study focuses on the microstructural
    evolution of heavy copper and heavy aluminum wires bonded on copper substrates.
    The evolution of the wire microstructure as well as the wire-substrate-interface
    was investigated by scanning electron microscope in combination with electron
    backscatter diffraction and microhardness measurements. Various samples were extracted
    at different points of the bonding process, namely the as-received condition,
    after touchdown and after completed bonding. The results of the aluminum and copper
    wires were compared to each other in both longitudinal and transversal direction.
    It was found, that the two wire materials were completely different in the as-received
    condition regarding the grain size, the grain morphology, the texture and the
    microhardness. After touchdown the microstructure did not show significant changes
    in both materials, yet a strain-hardening was observed in the copper wire resulting
    from the touchdown force. When the bonding process was completed a different microstructure
    could be observed in both the wire as well as the layer for the materials investigated.
    Furthermore, a destinctive increase in the wire hardness could be found in case
    of copper, which was not observed for the aluminum wire. The ramifications between
    the two wire materials presented in this work will be discussed with the objective
    of optimizing the quality of the bonds.
author:
- first_name: Florian
  full_name: Eacock , Florian
  last_name: 'Eacock '
- first_name: Mirko
  full_name: Schaper, Mirko
  last_name: Schaper
- first_name: Simon
  full_name: Althoff, Simon
  last_name: Althoff
- first_name: Andreas
  full_name: Unger, Andreas
  last_name: Unger
- first_name: Paul
  full_name: Eichwald, Paul
  last_name: Eichwald
- first_name: Florian
  full_name: Hengsbach, Florian
  last_name: Hengsbach
- first_name: Carolin
  full_name: Zinn, Carolin
  last_name: Zinn
- first_name: ' Martin Joachim'
  full_name: Holzweissig,  Martin Joachim
  last_name: Holzweissig
- first_name: Karsten
  full_name: Guth, Karsten
  last_name: Guth
citation:
  ama: 'Eacock  F, Schaper M, Althoff S, et al. Microstructural investigations of
    aluminum and copper wire bonds. In: <i>Proceedings of the 47th International Symposium
    on Microelectronics</i>. ; 2014. doi:<a href="https://doi.org/10.4071/isom-THP32">10.4071/isom-THP32</a>'
  apa: Eacock , F., Schaper, M., Althoff, S., Unger, A., Eichwald, P., Hengsbach,
    F., … Guth, K. (2014). Microstructural investigations of aluminum and copper wire
    bonds. In <i>Proceedings of the 47th International Symposium on Microelectronics</i>.
    <a href="https://doi.org/10.4071/isom-THP32">https://doi.org/10.4071/isom-THP32</a>
  bibtex: '@inproceedings{Eacock _Schaper_Althoff_Unger_Eichwald_Hengsbach_Zinn_Holzweissig_Guth_2014,
    title={Microstructural investigations of aluminum and copper wire bonds}, DOI={<a
    href="https://doi.org/10.4071/isom-THP32">10.4071/isom-THP32</a>}, booktitle={Proceedings
    of the 47th International Symposium on Microelectronics}, author={Eacock , Florian
    and Schaper, Mirko and Althoff, Simon and Unger, Andreas and Eichwald, Paul and
    Hengsbach, Florian and Zinn, Carolin and Holzweissig,  Martin Joachim and Guth,
    Karsten}, year={2014} }'
  chicago: Eacock , Florian, Mirko Schaper, Simon Althoff, Andreas Unger, Paul Eichwald,
    Florian Hengsbach, Carolin Zinn,  Martin Joachim Holzweissig, and Karsten Guth.
    “Microstructural Investigations of Aluminum and Copper Wire Bonds.” In <i>Proceedings
    of the 47th International Symposium on Microelectronics</i>, 2014. <a href="https://doi.org/10.4071/isom-THP32">https://doi.org/10.4071/isom-THP32</a>.
  ieee: F. Eacock  <i>et al.</i>, “Microstructural investigations of aluminum and
    copper wire bonds,” in <i>Proceedings of the 47th International Symposium on Microelectronics</i>,
    2014.
  mla: Eacock , Florian, et al. “Microstructural Investigations of Aluminum and Copper
    Wire Bonds.” <i>Proceedings of the 47th International Symposium on Microelectronics</i>,
    2014, doi:<a href="https://doi.org/10.4071/isom-THP32">10.4071/isom-THP32</a>.
  short: 'F. Eacock , M. Schaper, S. Althoff, A. Unger, P. Eichwald, F. Hengsbach,
    C. Zinn,  Martin Joachim Holzweissig, K. Guth, in: Proceedings of the 47th International
    Symposium on Microelectronics, 2014.'
date_created: 2019-05-20T12:14:11Z
date_updated: 2019-09-16T10:58:50Z
department:
- _id: '151'
doi: 10.4071/isom-THP32
keyword:
- Bonding
- Copper
- Microstructure evolution
language:
- iso: eng
publication: Proceedings of the 47th International Symposium on Microelectronics
quality_controlled: '1'
status: public
title: Microstructural investigations of aluminum and copper wire bonds
type: conference
user_id: '55222'
year: '2014'
...