---
_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: Proceedings of the 47th International Symposium
on Microelectronics. ; 2014. doi:10.4071/isom-THP32'
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 Proceedings of the 47th International Symposium on Microelectronics.
https://doi.org/10.4071/isom-THP32
bibtex: '@inproceedings{Eacock _Schaper_Althoff_Unger_Eichwald_Hengsbach_Zinn_Holzweissig_Guth_2014,
title={Microstructural investigations of aluminum and copper wire bonds}, DOI={10.4071/isom-THP32}, 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 Proceedings
of the 47th International Symposium on Microelectronics, 2014. https://doi.org/10.4071/isom-THP32.
ieee: F. Eacock et al., “Microstructural investigations of aluminum and
copper wire bonds,” in Proceedings of the 47th International Symposium on Microelectronics,
2014.
mla: Eacock , Florian, et al. “Microstructural Investigations of Aluminum and Copper
Wire Bonds.” Proceedings of the 47th International Symposium on Microelectronics,
2014, doi:10.4071/isom-THP32.
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'
...
---
_id: '9871'
abstract:
- lang: eng
text: 'Wire bonding is the most common technology for connecting electronic components.
Due to their efficiency bond interconnections made of copper wire are used for
example in the aerospace and medical technology as well as in the fields of renewable
energies. One of the main cost factors in the manufacturing process is the consumables
like bonding tools. The technological transition to copper as wire material causes
significant wear on the millimeter large effective contact area of the bonding
tool. This wear leads to a loss by a factor of 30 of the number of reliable interconnections
which can be produced by a single tool. To reduce setting-up time in the production
and minimizing costs, an enlarged bonding tool lifetime is desirable. Consequently
a better understanding of wear and recognition of wear pattern is required. Therefore,
the paper presents an analyzing method of the tool topography change of a heavy
wire bonding tool by using a confocal microscope. Furthermore, the paper discusses
the identification of the main wear indicators by the help of the named topography
change for different bond parameters, like ultrasonic power and tool geometry.
Reference topography has been carried out by choosing typical parameters of the
production line. To judge whether the quality requirement of the bond connections
made by a single tool cannot be fulfilled shear test of the source bond have been
carried out after a defined number of produced bond connections. Main steps of
analysis: (I)Topography of the tool surface is sampled after a defined number
of bonds by means of a confocal microscope to detect the wear progress.(II)The
recorded data is filtered using Matlab. So, measurement errors can be eliminated
and the topography can be overlaid more easy to identify differences between diverse
tools or differences in wear stages of the same tool.(III)The subsequent discretization
of the topography into sub volumes allows to (IV)describe the loss of volume depending
on the position in the groove. Thereby, intermediate status of wear of one tool
can be used to obtain a persistent description of the topography change over the
number of produced bonds by interpolating the confocal data. Afterwards the persistent
change of the groove flank has been analyzed for the named test series to identify
the main wear indicators and their effect on shear forces. All worn tools show
dominant areas for volume loss especially for plastic deformation and accordingly
abrasion. These wear mechanism can be referred to the change of main parts of
the groove geometry like the rounding of the front and back radius. The most volume
loss was identified in the upper part of the tool flanks or rather at the transition
from the groove flank to the front or back radius. Furthermore the observation
of the center of the groove flank shows just a little change in volume. All in
all, the identification of the wear indicators will be discussed with the objective
of increasing the tool lifetime by optimizing the tool geometry without losses
in bond quality and reliability.'
author:
- first_name: Paul
full_name: Eichwald, Paul
last_name: Eichwald
- first_name: Walter
full_name: Sextro, Walter
id: '21220'
last_name: Sextro
- first_name: Simon
full_name: Althof, Simon
last_name: Althof
- first_name: Florian
full_name: Eacock, Florian
last_name: Eacock
- first_name: Andreas
full_name: Unger, Andreas
last_name: Unger
- first_name: Tobias
full_name: Meyer, Tobias
last_name: Meyer
- first_name: Karsten
full_name: Guth, Karsten
last_name: Guth
citation:
ama: 'Eichwald P, Sextro W, Althof S, et al. Analysis Method of Tool Topography
Change and Identification of Wear Indicators for Heavy Copper Wire Wedge Bonding.
In: Proceedings of the 47th International Symposium on Microelectronics.
; 2014:856-861. doi:10.4071/isom-THP34'
apa: Eichwald, P., Sextro, W., Althof, S., Eacock, F., Unger, A., Meyer, T., &
Guth, K. (2014). Analysis Method of Tool Topography Change and Identification
of Wear Indicators for Heavy Copper Wire Wedge Bonding. In Proceedings of the
47th International Symposium on Microelectronics (pp. 856–861). https://doi.org/10.4071/isom-THP34
bibtex: '@inproceedings{Eichwald_Sextro_Althof_Eacock_Unger_Meyer_Guth_2014, title={Analysis
Method of Tool Topography Change and Identification of Wear Indicators for Heavy
Copper Wire Wedge Bonding}, DOI={10.4071/isom-THP34},
booktitle={Proceedings of the 47th International Symposium on Microelectronics},
author={Eichwald, Paul and Sextro, Walter and Althof, Simon and Eacock, Florian
and Unger, Andreas and Meyer, Tobias and Guth, Karsten}, year={2014}, pages={856–861}
}'
chicago: Eichwald, Paul, Walter Sextro, Simon Althof, Florian Eacock, Andreas Unger,
Tobias Meyer, and Karsten Guth. “Analysis Method of Tool Topography Change and
Identification of Wear Indicators for Heavy Copper Wire Wedge Bonding.” In Proceedings
of the 47th International Symposium on Microelectronics, 856–61, 2014. https://doi.org/10.4071/isom-THP34.
ieee: P. Eichwald et al., “Analysis Method of Tool Topography Change and
Identification of Wear Indicators for Heavy Copper Wire Wedge Bonding,” in Proceedings
of the 47th International Symposium on Microelectronics, 2014, pp. 856–861.
mla: Eichwald, Paul, et al. “Analysis Method of Tool Topography Change and Identification
of Wear Indicators for Heavy Copper Wire Wedge Bonding.” Proceedings of the
47th International Symposium on Microelectronics, 2014, pp. 856–61, doi:10.4071/isom-THP34.
short: 'P. Eichwald, W. Sextro, S. Althof, F. Eacock, A. Unger, T. Meyer, K. Guth,
in: Proceedings of the 47th International Symposium on Microelectronics, 2014,
pp. 856–861.'
date_created: 2019-05-20T12:18:55Z
date_updated: 2020-05-07T05:33:45Z
department:
- _id: '151'
doi: 10.4071/isom-THP34
keyword:
- wedge/wedge bonding
- copper wire
- tool wear
language:
- iso: eng
page: 856-861
project:
- _id: '92'
grant_number: 02 PQ2210
name: Intelligente Herstellung zuverlässiger Kupferbondverbindungen
publication: Proceedings of the 47th International Symposium on Microelectronics
status: public
title: Analysis Method of Tool Topography Change and Identification of Wear Indicators
for Heavy Copper Wire Wedge Bonding
type: conference
user_id: '210'
year: '2014'
...
---
_id: '9895'
abstract:
- lang: eng
text: Power semiconductor modules are used to control and switch high electrical
currents and voltages. Within the power module package wire bonding is used as
an interconnection technology. In recent years, aluminum wire has been used preferably,
but an ever-growing market of powerful and efficient power modules requires a
material with better mechanical and electrical properties. For this reason, a
technology change from aluminum to copper is indispensable. However, the copper
wire bonding process reacts more sensitive to parameter changes. This makes manufacturing
reliable copper bond connections a challenging task. The aim of the BMBF funded
project Itsowl-InCuB is the development of self-optimizing techniques to enable
the reliable production of copper bond connections under varying conditions. A
model of the process is essential to achieve this aim. This model needs to include
the dynamic elasto-plastic deformation, the ultrasonic softening effect and the
proceeding adhesion between wire and substrate. This paper focusses on the pre-deformation
process. In the touchdown phase, the wire is pressed into the V-groove of the
tool and a small initial contact area between wire and substrate arise. The local
characteristics of the material change abruptly because of the cold forming. Consequently,
the pre-deformation has a strong effect on the joining process. In [1], a pre-cleaning
effect during the touchdown process of aluminum wires by cracking of oxide layers
was presented. These interactions of the process parameters are still largely
unknown for copper. In a first step, this paper validates the importance of modeling
the pre-deformation by showing its impact on the wire deformation characteristic
experimentally. Creating cross-section views of pre-deformed copper wires has
shown a low deformation degree compared to aluminum. By using a digital microscope
and a scanning confocal microscope an analysis about the contact areas and penetration
depths after touchdown has been made. Additionally, it has to be taken into account
that the dynamical touchdown force depends on the touchdown speed and the touchdown
force set in the bonding machine. In order to measure the overshoot in the force
signals, a strain gauge sensor has been used. Subsequently, the affecting factors
have been interpreted independently Furthermore, the material properties of copper
wire have been investigated with tensile tests and hardness measurements. In a
second step, the paper presents finite element models of the touchdown process
for source and destination bonds. These models take the measured overshoot in
the touchdown forces into account. A multi-linear, isotropic material model has
been selected to map the material properties of the copper. A validation of the
model with the experimental determined contact areas, normal pressures and penetration
depths reveals the high model quality. Thus, the simulation is able to calculate
and visualize the three dimensional pre-deformation with an integrated material
parameter of the wire if the touchdown parameters of the bonding machine are known.
Based on the calculated deformation degrees of wire and substrate, it is probably
possible to investigate the effect of the pre-deformation on the pre-cleaning
phase in the copper wire bonding.
author:
- first_name: Andreas
full_name: Unger, Andreas
last_name: Unger
- first_name: Walter
full_name: Sextro, Walter
id: '21220'
last_name: Sextro
- first_name: Simon
full_name: Althoff, Simon
last_name: Althoff
- first_name: Paul
full_name: Eichwald, Paul
last_name: Eichwald
- first_name: Tobias
full_name: Meyer, Tobias
last_name: Meyer
- first_name: Florian
full_name: Eacock, Florian
last_name: Eacock
- first_name: Michael
full_name: Brökelmann, Michael
last_name: Brökelmann
citation:
ama: 'Unger A, Sextro W, Althoff S, et al. Experimental and Numerical Simulation
Study of Pre-Deformed Heavy Copper Wire Wedge Bonds. In: Proceedings of the
47th International Symposium on Microelectronics (IMAPS). San Diego, CA, US;
2014:289-294.'
apa: Unger, A., Sextro, W., Althoff, S., Eichwald, P., Meyer, T., Eacock, F., &
Brökelmann, M. (2014). Experimental and Numerical Simulation Study of Pre-Deformed
Heavy Copper Wire Wedge Bonds. In Proceedings of the 47th International Symposium
on Microelectronics (IMAPS) (pp. 289–294). San Diego, CA, US.
bibtex: '@inproceedings{Unger_Sextro_Althoff_Eichwald_Meyer_Eacock_Brökelmann_2014,
place={San Diego, CA, US}, title={Experimental and Numerical Simulation Study
of Pre-Deformed Heavy Copper Wire Wedge Bonds}, booktitle={Proceedings of the
47th International Symposium on Microelectronics (IMAPS)}, author={Unger, Andreas
and Sextro, Walter and Althoff, Simon and Eichwald, Paul and Meyer, Tobias and
Eacock, Florian and Brökelmann, Michael}, year={2014}, pages={289–294} }'
chicago: Unger, Andreas, Walter Sextro, Simon Althoff, Paul Eichwald, Tobias Meyer,
Florian Eacock, and Michael Brökelmann. “Experimental and Numerical Simulation
Study of Pre-Deformed Heavy Copper Wire Wedge Bonds.” In Proceedings of the
47th International Symposium on Microelectronics (IMAPS), 289–94. San Diego,
CA, US, 2014.
ieee: A. Unger et al., “Experimental and Numerical Simulation Study of Pre-Deformed
Heavy Copper Wire Wedge Bonds,” in Proceedings of the 47th International Symposium
on Microelectronics (IMAPS), 2014, pp. 289–294.
mla: Unger, Andreas, et al. “Experimental and Numerical Simulation Study of Pre-Deformed
Heavy Copper Wire Wedge Bonds.” Proceedings of the 47th International Symposium
on Microelectronics (IMAPS), 2014, pp. 289–94.
short: 'A. Unger, W. Sextro, S. Althoff, P. Eichwald, T. Meyer, F. Eacock, M. Brökelmann,
in: Proceedings of the 47th International Symposium on Microelectronics (IMAPS),
San Diego, CA, US, 2014, pp. 289–294.'
date_created: 2019-05-20T13:35:09Z
date_updated: 2020-05-07T05:33:47Z
department:
- _id: '151'
keyword:
- pre-deformation
- copper wire bonding
- finite element model
language:
- iso: eng
page: 289-294
place: San Diego, CA, US
project:
- _id: '92'
grant_number: 02 PQ2210
name: Intelligente Herstellung zuverlässiger Kupferbondverbindungen
publication: Proceedings of the 47th International Symposium on Microelectronics (IMAPS)
status: public
title: Experimental and Numerical Simulation Study of Pre-Deformed Heavy Copper Wire
Wedge Bonds
type: conference
user_id: '210'
year: '2014'
...
---
_id: '4548'
abstract:
- lang: eng
text: "A fluorescence study of acetonitrile solutions of bis(tetramethylguanidine)propane,
copper(I)-iodide and [Cu(btmgp)I] was performed and the chemical reaction of the
latter species with O2 was investigated at room temperature. The actual quenching
process via O2 gassing was studied and an exponential dependence of the fluorescence
intensity with respect to the complex concentration was observed.\r\nFurthermore
the survey was deepened on time resolved fluorescence properties of solved [Cu(btmgp)I]
in a wider concentration range. The applicability of this complex for O2 sensing
inside a microreactor system was proven by confocal fluorescence measurements.
It was shown that the investigated system can be used for oxygen sensing in the
copper concentration range from 10−2 to 10−9 mol/l."
article_type: original
author:
- first_name: Sonja
full_name: Herres-Pawlis, Sonja
last_name: Herres-Pawlis
- first_name: Gerhard
full_name: Berth, Gerhard
id: '53'
last_name: Berth
- first_name: Volker
full_name: Wiedemeier, Volker
last_name: Wiedemeier
- first_name: Ludger
full_name: Schmidt, Ludger
last_name: Schmidt
- first_name: Artur
full_name: Zrenner, Artur
id: '606'
last_name: Zrenner
orcid: 0000-0002-5190-0944
- first_name: Hans-Joachim
full_name: Warnecke, Hans-Joachim
last_name: Warnecke
citation:
ama: Herres-Pawlis S, Berth G, Wiedemeier V, Schmidt L, Zrenner A, Warnecke H-J.
Oxygen sensing by fluorescence quenching of [Cu(btmgp)I]. Journal of Luminescence.
2010;130(10):1958-1962. doi:10.1016/j.jlumin.2010.05.012
apa: Herres-Pawlis, S., Berth, G., Wiedemeier, V., Schmidt, L., Zrenner, A., &
Warnecke, H.-J. (2010). Oxygen sensing by fluorescence quenching of [Cu(btmgp)I].
Journal of Luminescence, 130(10), 1958–1962. https://doi.org/10.1016/j.jlumin.2010.05.012
bibtex: '@article{Herres-Pawlis_Berth_Wiedemeier_Schmidt_Zrenner_Warnecke_2010,
title={Oxygen sensing by fluorescence quenching of [Cu(btmgp)I]}, volume={130},
DOI={10.1016/j.jlumin.2010.05.012},
number={10}, journal={Journal of Luminescence}, publisher={Elsevier BV}, author={Herres-Pawlis,
Sonja and Berth, Gerhard and Wiedemeier, Volker and Schmidt, Ludger and Zrenner,
Artur and Warnecke, Hans-Joachim}, year={2010}, pages={1958–1962} }'
chicago: 'Herres-Pawlis, Sonja, Gerhard Berth, Volker Wiedemeier, Ludger Schmidt,
Artur Zrenner, and Hans-Joachim Warnecke. “Oxygen Sensing by Fluorescence Quenching
of [Cu(Btmgp)I].” Journal of Luminescence 130, no. 10 (2010): 1958–62.
https://doi.org/10.1016/j.jlumin.2010.05.012.'
ieee: S. Herres-Pawlis, G. Berth, V. Wiedemeier, L. Schmidt, A. Zrenner, and H.-J.
Warnecke, “Oxygen sensing by fluorescence quenching of [Cu(btmgp)I],” Journal
of Luminescence, vol. 130, no. 10, pp. 1958–1962, 2010.
mla: Herres-Pawlis, Sonja, et al. “Oxygen Sensing by Fluorescence Quenching of [Cu(Btmgp)I].”
Journal of Luminescence, vol. 130, no. 10, Elsevier BV, 2010, pp. 1958–62,
doi:10.1016/j.jlumin.2010.05.012.
short: S. Herres-Pawlis, G. Berth, V. Wiedemeier, L. Schmidt, A. Zrenner, H.-J.
Warnecke, Journal of Luminescence 130 (2010) 1958–1962.
date_created: 2018-09-20T12:31:16Z
date_updated: 2022-01-06T07:01:09Z
department:
- _id: '15'
- _id: '230'
- _id: '35'
doi: 10.1016/j.jlumin.2010.05.012
intvolume: ' 130'
issue: '10'
keyword:
- Copper Oxygen Fluorescence quenching N donor ligands
language:
- iso: eng
page: 1958-1962
publication: Journal of Luminescence
publication_identifier:
issn:
- 0022-2313
publication_status: published
publisher: Elsevier BV
status: public
title: Oxygen sensing by fluorescence quenching of [Cu(btmgp)I]
type: journal_article
user_id: '49428'
volume: 130
year: '2010'
...