[{"citation":{"ama":"Eacock F, Unger A, Eichwald P, et al. Effect of different oxide layers on the ultrasonic copper wire bond process. In: <i>IEEE 66th Electronic Components and Technology Conference</i>. ; 2016:2111-2118. doi:<a href=\"https://doi.org/10.1109/ECTC.2016.91\">10.1109/ECTC.2016.91</a>","chicago":"Eacock, Florian, Andreas Unger, Paul Eichwald, Olexandr Grydin, Florian Hengsbach, Simon Althoff, Mirko Schaper, and Karsten Guth. “Effect of Different Oxide Layers on the Ultrasonic Copper Wire Bond Process.” In <i>IEEE 66th Electronic Components and Technology Conference</i>, 2111–18, 2016. <a href=\"https://doi.org/10.1109/ECTC.2016.91\">https://doi.org/10.1109/ECTC.2016.91</a>.","ieee":"F. Eacock <i>et al.</i>, “Effect of different oxide layers on the ultrasonic copper wire bond process,” in <i>IEEE 66th Electronic Components and Technology Conference</i>, 2016, pp. 2111–2118.","short":"F. Eacock, A. Unger, P. Eichwald, O. Grydin, F. Hengsbach, S. Althoff, M. Schaper, K. Guth, in: IEEE 66th Electronic Components and Technology Conference, 2016, pp. 2111–2118.","bibtex":"@inproceedings{Eacock_Unger_Eichwald_Grydin_Hengsbach_Althoff_Schaper_Guth_2016, title={Effect of different oxide layers on the ultrasonic copper wire bond process}, DOI={<a href=\"https://doi.org/10.1109/ECTC.2016.91\">10.1109/ECTC.2016.91</a>}, booktitle={IEEE 66th Electronic Components and Technology Conference}, author={Eacock, Florian and Unger, Andreas and Eichwald, Paul and Grydin, Olexandr and Hengsbach, Florian and Althoff, Simon and Schaper, Mirko and Guth, Karsten}, year={2016}, pages={2111–2118} }","mla":"Eacock, Florian, et al. “Effect of Different Oxide Layers on the Ultrasonic Copper Wire Bond Process.” <i>IEEE 66th Electronic Components and Technology Conference</i>, 2016, pp. 2111–18, doi:<a href=\"https://doi.org/10.1109/ECTC.2016.91\">10.1109/ECTC.2016.91</a>.","apa":"Eacock, F., Unger, A., Eichwald, P., Grydin, O., Hengsbach, F., Althoff, S., … Guth, K. (2016). Effect of different oxide layers on the ultrasonic copper wire bond process. In <i>IEEE 66th Electronic Components and Technology Conference</i> (pp. 2111–2118). <a href=\"https://doi.org/10.1109/ECTC.2016.91\">https://doi.org/10.1109/ECTC.2016.91</a>"},"page":"2111-2118","year":"2016","quality_controlled":"1","doi":"10.1109/ECTC.2016.91","title":"Effect of different oxide layers on the ultrasonic copper wire bond process","date_created":"2019-05-27T09:00:50Z","author":[{"full_name":"Eacock, Florian","last_name":"Eacock","first_name":"Florian"},{"first_name":"Andreas","full_name":"Unger, Andreas","last_name":"Unger"},{"first_name":"Paul","last_name":"Eichwald","full_name":"Eichwald, Paul"},{"first_name":"Olexandr","last_name":"Grydin","full_name":"Grydin, Olexandr"},{"first_name":"Florian","full_name":"Hengsbach, Florian","last_name":"Hengsbach"},{"first_name":"Simon","full_name":"Althoff, Simon","last_name":"Althoff"},{"first_name":"Mirko","full_name":"Schaper, Mirko","last_name":"Schaper"},{"first_name":"Karsten","last_name":"Guth","full_name":"Guth, Karsten"}],"date_updated":"2019-09-16T10:38:59Z","status":"public","abstract":[{"lang":"eng","text":"Ultrasonic heavy wire bonding is a commonly used technology to conduct electrical devices in power electronics. In order to facilitate powerful solutions combined with an increased efficiency, involving a material change from aluminum to copper wire as conductor material takes place in recent years. Due to the material related properties, copper wire bonding requires significant higher bond processing parameters such as bond force and ultrasonic power compared to aluminum which can lead to damages or a failure of the bonded component. Therefore, a profound knowledge of the processes prevailing during wire bonding is essential to optimize the application of the copper wires and consequently to achieve the demands on quality and reliability. The behavior of different natural surface oxides of aluminum and copper are assumed to be one reason for the deviation in the required bond parameters. Accordingly, the impact of differently pre-treated substrates surfaces on which the bonding is applied were investigated in this study. First, all conditions investigated (as-received, oxidefree, AlOx and the CuOx) were characterized by utilizing scanning electron microscopy, energy dispersive X-ray spectroscopy, focused ion beam microscopy and atomic force microscopy. In addition, hardness tests were performed as well as perthometer measurements. Afterwards, a 500 $\\mu$ m copper wire was bonded on the generated surfaces investigated. In consideration of the roughness, shear test of various bond times and microscopic images were evaluated. Finally, the results were compared and discussed. Overall, the current study indicates that an Al-oxide layer is beneficial for welding process in Cu wire bonding. On the contrary, the Cu-oxide is detrimental and leads to a delayed welding of the joining parts. Based on the obtained results, it can be expected that due to an ideal set of Al-oxide layers, lower optimal bond parameters can used to reach high bond strength with good reliability properties."}],"type":"conference","publication":"IEEE 66th Electronic Components and Technology Conference","language":[{"iso":"eng"}],"keyword":["Ultrasonic copper wire bonding","Al-oxide","Cuoxide","oxide-free","roughness","morphology"],"user_id":"55222","department":[{"_id":"151"}],"_id":"9959"},{"author":[{"first_name":"Simon","full_name":"Althoff, Simon","last_name":"Althoff"},{"full_name":"Neuhaus, Jan","last_name":"Neuhaus","first_name":"Jan"},{"full_name":"Hemsel, Tobias","id":"210","last_name":"Hemsel","first_name":"Tobias"},{"last_name":"Sextro","id":"21220","full_name":"Sextro, Walter","first_name":"Walter"}],"date_created":"2019-05-20T12:11:44Z","date_updated":"2019-09-16T10:57:58Z","doi":"10.1109/ECTC.2014.6897500","title":"Improving the bond quality of copper wire bonds using a friction model approach","quality_controlled":"1","page":"1549-1555","citation":{"bibtex":"@inproceedings{Althoff_Neuhaus_Hemsel_Sextro_2014, title={Improving the bond quality of copper wire bonds using a friction model approach}, DOI={<a href=\"https://doi.org/10.1109/ECTC.2014.6897500\">10.1109/ECTC.2014.6897500</a>}, booktitle={Electronic Components and Technology Conference (ECTC), 2014 IEEE 64th}, author={Althoff, Simon and Neuhaus, Jan and Hemsel, Tobias and Sextro, Walter}, year={2014}, pages={1549–1555} }","short":"S. Althoff, J. Neuhaus, T. Hemsel, W. Sextro, in: Electronic Components and Technology Conference (ECTC), 2014 IEEE 64th, 2014, pp. 1549–1555.","mla":"Althoff, Simon, et al. “Improving the Bond Quality of Copper Wire Bonds Using a Friction Model Approach.” <i>Electronic Components and Technology Conference (ECTC), 2014 IEEE 64th</i>, 2014, pp. 1549–55, doi:<a href=\"https://doi.org/10.1109/ECTC.2014.6897500\">10.1109/ECTC.2014.6897500</a>.","apa":"Althoff, S., Neuhaus, J., Hemsel, T., &#38; Sextro, W. (2014). Improving the bond quality of copper wire bonds using a friction model approach. In <i>Electronic Components and Technology Conference (ECTC), 2014 IEEE 64th</i> (pp. 1549–1555). <a href=\"https://doi.org/10.1109/ECTC.2014.6897500\">https://doi.org/10.1109/ECTC.2014.6897500</a>","ama":"Althoff S, Neuhaus J, Hemsel T, Sextro W. Improving the bond quality of copper wire bonds using a friction model approach. In: <i>Electronic Components and Technology Conference (ECTC), 2014 IEEE 64th</i>. ; 2014:1549-1555. doi:<a href=\"https://doi.org/10.1109/ECTC.2014.6897500\">10.1109/ECTC.2014.6897500</a>","ieee":"S. Althoff, J. Neuhaus, T. Hemsel, and W. Sextro, “Improving the bond quality of copper wire bonds using a friction model approach,” in <i>Electronic Components and Technology Conference (ECTC), 2014 IEEE 64th</i>, 2014, pp. 1549–1555.","chicago":"Althoff, Simon, Jan Neuhaus, Tobias Hemsel, and Walter Sextro. “Improving the Bond Quality of Copper Wire Bonds Using a Friction Model Approach.” In <i>Electronic Components and Technology Conference (ECTC), 2014 IEEE 64th</i>, 1549–55, 2014. <a href=\"https://doi.org/10.1109/ECTC.2014.6897500\">https://doi.org/10.1109/ECTC.2014.6897500</a>."},"year":"2014","department":[{"_id":"151"}],"user_id":"55222","_id":"9868","language":[{"iso":"eng"}],"keyword":["adhesion","circuit reliability","deformation","diffusion","fatigue cracks","friction","interconnections","lead bonding","van der Waals forces","Cu","adhering process","adhesion process","ampacity improvement","bond quality improvement","cleaning process","diffusing process","fatigue fracture failure","friction energy","friction model","heat dissipation","mechanical strength","piezoelectric triaxial force sensor","predeforming process","size 500 mum","total contact area","van der Waals forces","wedge copper wire bonding","Bonding","Copper","Finite element analysis","Force","Friction","Substrates","Wires"],"publication":"Electronic Components and Technology Conference (ECTC), 2014 IEEE 64th","type":"conference","status":"public","abstract":[{"lang":"eng","text":"In order to increase mechanical strength, heat dissipation and ampacity and to decrease failure through fatigue fracture, wedge copper wire bonding is being introduced as a standard interconnection method for mass production. To achieve the same process stability when using copper wire instead of aluminum wire a profound understanding of the bonding process is needed. Due to the higher hardness of copper compared to aluminum wire it is more difficult to approach the surfaces of wire and substrate to a level where van der Waals forces are able to arise between atoms. Also, enough friction energy referred to the total contact area has to be generated to activate the surfaces. Therefore, a friction model is used to simulate the joining process. This model calculates the resulting energy of partial areas in the contact surface and provides information about the adhesion process of each area. The focus here is on the arising of micro joints in the contact area depending on the location in the contact and time. To validate the model, different touchdown forces are used to vary the initial contact areas of wire and substrate. Additionally, a piezoelectric tri-axial force sensor is built up to identify the known phases of pre-deforming, cleaning, adhering and diffusing for the real bonding process to map with the model. Test substrates as DBC and copper plate are used to show the different formations of a wedge bond connection due to hardness and reaction propensity. The experiments were done by using 500 $\\mu$m copper wire and a standard V-groove tool."}]},{"title":"Experimental and Numerical Simulation Study of Pre-Deformed Heavy Copper Wire Wedge Bonds","date_created":"2019-05-20T13:35:09Z","author":[{"full_name":"Unger, Andreas","last_name":"Unger","first_name":"Andreas"},{"full_name":"Sextro, Walter","id":"21220","last_name":"Sextro","first_name":"Walter"},{"last_name":"Althoff","full_name":"Althoff, Simon","first_name":"Simon"},{"first_name":"Paul","full_name":"Eichwald, Paul","last_name":"Eichwald"},{"full_name":"Meyer, Tobias","last_name":"Meyer","first_name":"Tobias"},{"last_name":"Eacock","full_name":"Eacock, Florian","first_name":"Florian"},{"first_name":"Michael","full_name":"Brökelmann, Michael","last_name":"Brökelmann"}],"date_updated":"2020-05-07T05:33:47Z","citation":{"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.","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} }","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.","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.","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."},"page":"289-294","year":"2014","place":"San Diego, CA, US","language":[{"iso":"eng"}],"keyword":["pre-deformation","copper wire bonding","finite element model"],"user_id":"210","department":[{"_id":"151"}],"project":[{"name":"Intelligente Herstellung zuverlässiger Kupferbondverbindungen","_id":"92","grant_number":"02 PQ2210"}],"_id":"9895","status":"public","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."}],"type":"conference","publication":"Proceedings of the 47th International Symposium on Microelectronics (IMAPS)"}]