[{"year":"2014","title":"Microstructural investigations of aluminum and copper wire bonds","status":"public","author":[{"full_name":"Eacock , Florian","first_name":"Florian","last_name":"Eacock "},{"full_name":"Schaper, Mirko","last_name":"Schaper","first_name":"Mirko"},{"last_name":"Althoff","first_name":"Simon","full_name":"Althoff, Simon"},{"full_name":"Unger, Andreas","first_name":"Andreas","last_name":"Unger"},{"first_name":"Paul","last_name":"Eichwald","full_name":"Eichwald, Paul"},{"last_name":"Hengsbach","first_name":"Florian","full_name":"Hengsbach, Florian"},{"full_name":"Zinn, Carolin","first_name":"Carolin","last_name":"Zinn"},{"full_name":"Holzweissig,  Martin Joachim","first_name":" Martin Joachim","last_name":"Holzweissig"},{"last_name":"Guth","first_name":"Karsten","full_name":"Guth, Karsten"}],"date_updated":"2019-09-16T10:58:50Z","language":[{"iso":"eng"}],"_id":"9870","user_id":"55222","doi":"10.4071/isom-THP32","publication":"Proceedings of the 47th International Symposium on Microelectronics","citation":{"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} }","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>","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.","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.","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>"},"abstract":[{"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.","lang":"eng"}],"quality_controlled":"1","date_created":"2019-05-20T12:14:11Z","type":"conference","keyword":["Bonding","Copper","Microstructure evolution"],"department":[{"_id":"151"}]},{"date_updated":"2020-05-07T05:33:45Z","author":[{"full_name":"Eichwald, Paul","first_name":"Paul","last_name":"Eichwald"},{"id":"21220","last_name":"Sextro","first_name":"Walter","full_name":"Sextro, Walter"},{"full_name":"Althof, Simon","last_name":"Althof","first_name":"Simon"},{"last_name":"Eacock","first_name":"Florian","full_name":"Eacock, Florian"},{"full_name":"Unger, Andreas","last_name":"Unger","first_name":"Andreas"},{"last_name":"Meyer","first_name":"Tobias","full_name":"Meyer, Tobias"},{"full_name":"Guth, Karsten","first_name":"Karsten","last_name":"Guth"}],"status":"public","year":"2014","title":"Analysis Method of Tool Topography Change and Identification of Wear Indicators for Heavy Copper Wire Wedge Bonding","user_id":"210","doi":"10.4071/isom-THP34","_id":"9871","language":[{"iso":"eng"}],"page":"856-861","project":[{"_id":"92","grant_number":"02 PQ2210","name":"Intelligente Herstellung zuverlässiger Kupferbondverbindungen"}],"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."}],"citation":{"ieee":"P. Eichwald <i>et al.</i>, “Analysis Method of Tool Topography Change and Identification of Wear Indicators for Heavy Copper Wire Wedge Bonding,” in <i>Proceedings of the 47th International Symposium on Microelectronics</i>, 2014, pp. 856–861.","apa":"Eichwald, P., Sextro, W., Althof, S., Eacock, F., Unger, A., Meyer, T., &#38; Guth, K. (2014). Analysis Method of Tool Topography Change and Identification of Wear Indicators for Heavy Copper Wire Wedge Bonding. In <i>Proceedings of the 47th International Symposium on Microelectronics</i> (pp. 856–861). <a href=\"https://doi.org/10.4071/isom-THP34\">https://doi.org/10.4071/isom-THP34</a>","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 <i>Proceedings of the 47th International Symposium on Microelectronics</i>, 856–61, 2014. <a href=\"https://doi.org/10.4071/isom-THP34\">https://doi.org/10.4071/isom-THP34</a>.","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.","mla":"Eichwald, Paul, et al. “Analysis Method of Tool Topography Change and Identification of Wear Indicators for Heavy Copper Wire Wedge Bonding.” <i>Proceedings of the 47th International Symposium on Microelectronics</i>, 2014, pp. 856–61, doi:<a href=\"https://doi.org/10.4071/isom-THP34\">10.4071/isom-THP34</a>.","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={<a href=\"https://doi.org/10.4071/isom-THP34\">10.4071/isom-THP34</a>}, 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} }","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: <i>Proceedings of the 47th International Symposium on Microelectronics</i>. ; 2014:856-861. doi:<a href=\"https://doi.org/10.4071/isom-THP34\">10.4071/isom-THP34</a>"},"publication":"Proceedings of the 47th International Symposium on Microelectronics","department":[{"_id":"151"}],"type":"conference","keyword":["wedge/wedge bonding","copper wire","tool wear"],"date_created":"2019-05-20T12:18:55Z"},{"date_created":"2019-05-20T13:35:09Z","place":"San Diego, CA, US","type":"conference","keyword":["pre-deformation","copper wire bonding","finite element model"],"department":[{"_id":"151"}],"publication":"Proceedings of the 47th International Symposium on Microelectronics (IMAPS)","citation":{"mla":"Unger, Andreas, et al. “Experimental and Numerical Simulation Study of Pre-Deformed Heavy Copper Wire Wedge Bonds.” <i>Proceedings of the 47th International Symposium on Microelectronics (IMAPS)</i>, 2014, pp. 289–94.","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} }","ama":"Unger A, Sextro W, Althoff S, et al. Experimental and Numerical Simulation Study of Pre-Deformed Heavy Copper Wire Wedge Bonds. In: <i>Proceedings of the 47th International Symposium on Microelectronics (IMAPS)</i>. San Diego, CA, US; 2014:289-294.","ieee":"A. Unger <i>et al.</i>, “Experimental and Numerical Simulation Study of Pre-Deformed Heavy Copper Wire Wedge Bonds,” in <i>Proceedings of the 47th International Symposium on Microelectronics (IMAPS)</i>, 2014, pp. 289–294.","apa":"Unger, A., Sextro, W., Althoff, S., Eichwald, P., Meyer, T., Eacock, F., &#38; Brökelmann, M. (2014). Experimental and Numerical Simulation Study of Pre-Deformed Heavy Copper Wire Wedge Bonds. In <i>Proceedings of the 47th International Symposium on Microelectronics (IMAPS)</i> (pp. 289–294). San Diego, CA, US.","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.","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 <i>Proceedings of the 47th International Symposium on Microelectronics (IMAPS)</i>, 289–94. San Diego, CA, US, 2014."},"abstract":[{"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.","lang":"eng"}],"project":[{"name":"Intelligente Herstellung zuverlässiger Kupferbondverbindungen","grant_number":"02 PQ2210","_id":"92"}],"page":"289-294","language":[{"iso":"eng"}],"_id":"9895","user_id":"210","status":"public","title":"Experimental and Numerical Simulation Study of Pre-Deformed Heavy Copper Wire Wedge Bonds","year":"2014","author":[{"first_name":"Andreas","last_name":"Unger","full_name":"Unger, Andreas"},{"id":"21220","full_name":"Sextro, Walter","first_name":"Walter","last_name":"Sextro"},{"full_name":"Althoff, Simon","first_name":"Simon","last_name":"Althoff"},{"first_name":"Paul","last_name":"Eichwald","full_name":"Eichwald, Paul"},{"first_name":"Tobias","last_name":"Meyer","full_name":"Meyer, Tobias"},{"full_name":"Eacock, Florian","first_name":"Florian","last_name":"Eacock"},{"full_name":"Brökelmann, Michael","first_name":"Michael","last_name":"Brökelmann"}],"date_updated":"2020-05-07T05:33:47Z"},{"status":"public","volume":130,"user_id":"49428","_id":"4548","publisher":"Elsevier BV","page":"1958-1962","citation":{"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].” <i>Journal of Luminescence</i> 130, no. 10 (2010): 1958–62. <a href=\"https://doi.org/10.1016/j.jlumin.2010.05.012\">https://doi.org/10.1016/j.jlumin.2010.05.012</a>.","ama":"Herres-Pawlis S, Berth G, Wiedemeier V, Schmidt L, Zrenner A, Warnecke H-J. Oxygen sensing by fluorescence quenching of [Cu(btmgp)I]. <i>Journal of Luminescence</i>. 2010;130(10):1958-1962. doi:<a href=\"https://doi.org/10.1016/j.jlumin.2010.05.012\">10.1016/j.jlumin.2010.05.012</a>","short":"S. Herres-Pawlis, G. Berth, V. Wiedemeier, L. Schmidt, A. Zrenner, H.-J. Warnecke, Journal of Luminescence 130 (2010) 1958–1962.","bibtex":"@article{Herres-Pawlis_Berth_Wiedemeier_Schmidt_Zrenner_Warnecke_2010, title={Oxygen sensing by fluorescence quenching of [Cu(btmgp)I]}, volume={130}, DOI={<a href=\"https://doi.org/10.1016/j.jlumin.2010.05.012\">10.1016/j.jlumin.2010.05.012</a>}, 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} }","apa":"Herres-Pawlis, S., Berth, G., Wiedemeier, V., Schmidt, L., Zrenner, A., &#38; Warnecke, H.-J. (2010). Oxygen sensing by fluorescence quenching of [Cu(btmgp)I]. <i>Journal of Luminescence</i>, <i>130</i>(10), 1958–1962. <a href=\"https://doi.org/10.1016/j.jlumin.2010.05.012\">https://doi.org/10.1016/j.jlumin.2010.05.012</a>","mla":"Herres-Pawlis, Sonja, et al. “Oxygen Sensing by Fluorescence Quenching of [Cu(Btmgp)I].” <i>Journal of Luminescence</i>, vol. 130, no. 10, Elsevier BV, 2010, pp. 1958–62, doi:<a href=\"https://doi.org/10.1016/j.jlumin.2010.05.012\">10.1016/j.jlumin.2010.05.012</a>.","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],” <i>Journal of Luminescence</i>, vol. 130, no. 10, pp. 1958–1962, 2010."},"article_type":"original","intvolume":"       130","publication_status":"published","date_updated":"2022-01-06T07:01:09Z","publication_identifier":{"issn":["0022-2313"]},"author":[{"full_name":"Herres-Pawlis, Sonja","last_name":"Herres-Pawlis","first_name":"Sonja"},{"full_name":"Berth, Gerhard","last_name":"Berth","first_name":"Gerhard","id":"53"},{"first_name":"Volker","last_name":"Wiedemeier","full_name":"Wiedemeier, Volker"},{"last_name":"Schmidt","first_name":"Ludger","full_name":"Schmidt, Ludger"},{"id":"606","full_name":"Zrenner, Artur","orcid":"0000-0002-5190-0944","last_name":"Zrenner","first_name":"Artur"},{"last_name":"Warnecke","first_name":"Hans-Joachim","full_name":"Warnecke, Hans-Joachim"}],"title":"Oxygen sensing by fluorescence quenching of [Cu(btmgp)I]","year":"2010","doi":"10.1016/j.jlumin.2010.05.012","language":[{"iso":"eng"}],"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."}],"issue":"10","publication":"Journal of Luminescence","department":[{"_id":"15"},{"_id":"230"},{"_id":"35"}],"type":"journal_article","keyword":["Copper Oxygen Fluorescence quenching N donor ligands"],"date_created":"2018-09-20T12:31:16Z"}]