Potentials of Inductively Heated Tools for Contacting Primary-insulated Copper Litz Wires without Contact Element

Eichinger M, Kühl A, Baader M, Franke J, Risch F (2025)


Publication Type: Conference contribution

Publication year: 2025

Journal

Publisher: Institute of Electrical and Electronics Engineers Inc.

Conference Proceedings Title: Electrical Contacts, Proceedings of the Annual Holm Conference on Electrical Contacts

Event location: San Antonio, TX, USA

ISBN: 9798331559960

DOI: 10.1109/HLM51652.2025.11278389

Abstract

To avoid skin and proximity effects, individually insulated copper strands - high-frequency litz wires (HF litz wires) - are used in inductive charging pads for electric vehicles. However, this insulation has to be removed in order to create an electrical contact at the end of the copper strand. Hot crimping with a contact element is currently the industry standard for contacting insulated HF litz wires. However, the hot crimping process is not temperature controlled, so the temperature in the joining zone will vary to some extent. In addition, a contact element is always needed to transmit power between the electrodes. This paper investigates the influence of inductively heated tools on the connection quality of insulated copper strands without a contact element. The synchronized heating of the tools and the forming of the strands results in a combined process in which stripping and contacting take place simultaneously. Similar to hot crimping, the liquidus temperature of the copper wire is not reached, but only the insulation is burned off. The objective of the research is to identify a process window for the described contacting process, further referred to as compacting, and to analyze significant factors and interactions that affect the mechanical and electrical quality of the connection.

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How to cite

APA:

Eichinger, M., Kühl, A., Baader, M., Franke, J., & Risch, F. (2025). Potentials of Inductively Heated Tools for Contacting Primary-insulated Copper Litz Wires without Contact Element. In Electrical Contacts, Proceedings of the Annual Holm Conference on Electrical Contacts. San Antonio, TX, USA: Institute of Electrical and Electronics Engineers Inc..

MLA:

Eichinger, Miriam, et al. "Potentials of Inductively Heated Tools for Contacting Primary-insulated Copper Litz Wires without Contact Element." Proceedings of the 70th IEEE Holm Conference on Electrical Contacts, HOLM 2025, San Antonio, TX, USA Institute of Electrical and Electronics Engineers Inc., 2025.

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