| Peer-Reviewed

Integrated Transformer with Buried Windings in Ferrite Core

Received: 15 January 2022    Accepted: 27 January 2022    Published: 9 February 2022
Views:       Downloads:
Abstract

In the field of electronics, one of the objectives of current research is to integrate numerous components in increasingly smaller volumes. Reducing the cost of manufacturing components requires integration and collective manufacturing. This paper mainly focuses on the design and the main steps of the micro-fabrication of a transformer with magnetic layers. Windings have been buried in a ferrite core by using Femtosecond Laser Micromachining. Such a burying of windings avoids air gap and greatly increases primary and secondary inductances. Different technological steps from copper deposition to the realization of the grooves in the magnetic material (in the case of the buried transformer) through etching, gilding, lapping, sawing, polishing and gluing have been described. We also used a negative photoresist (SU-8) as an insulating layer and as a support for the fabrication of an air bridge to connect the center pad of the coils to the ground plane. The micro-transformer was characterized with a Vector Network Analyzer and the bandwidth was observed from 20 kHz to 7 MHz. The gain in the bandwidth is equal to 0,86. The buried conductors allow to increase the magnetizing inductance of the transformer and the shift of 45° between the primary and secondary windings allows to decrease the capacitive coupling.

Published in Journal of Electrical and Electronic Engineering (Volume 10, Issue 1)
DOI 10.11648/j.jeee.20221001.12
Page(s) 10-17
Creative Commons

This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.

Copyright

Copyright © The Author(s), 2024. Published by Science Publishing Group

Keywords

Integrated Micro-transformer, Femtosecond Laser Micromachining, Buried Windings, Ferrite

References
[1] D.-H. Weon and Saeed Mohammadi. (2007). High-Inductance-Density, AirCore, Power Inductors, and Transformers Designed for Operation at 100–500 MHz. IEEE High Performance 3-D Helical RF Transformers, pp. 1897-1900. Doi: 10.1109/TMAG.2010.2045742.
[2] Chinchun Meng, Ya-Hui Teng, Yi-Chen Lin, Jhin-Ci Jhong and YingChieh Yen. (2007). Characterisatics of Integrated RF Transfomers on GaAs Substrats. IEEE Proceeding of Asia-Pacific Microwave Conference, pp. 1.4. Doi: 10.1109/APMC.2007.4554720.
[3] Jumril Yunas, Burhanuddin Yeop Majlis. (2008). Comparative study of stack interwinding micro-transformers on silicon monolithic. Microelectronics Journal, vol. 39, issue. 12, pp. 1564-1567. Doi: 10.1016/j.mejo.2008.02.026.
[4] Christopher D. Meyer, Sarah S. Bedair, Brian C. Morgan, and David P. Arnold. (2010). High-Inductance-Density, Air-Core, Power Inductors, and Transformers Designed for Operation at 100–500 MHz. IEEE Transactions On Magnetics, vol. 46, pp. 2236-2239, Juin 2010. DOI: 10.1109/TMAG.2010.2045742.
[5] Shlomo Katz, IgorBrouk, SaraStolyarov, ShyeShapira, YaelNemirovsky. (2012). High performance MEMS 0.18 µm RF-CMOS transformers. Microelectronics Journal, vol. 43, pp. 13-16. DOI: 10.1109/COMCAS.2009.5386016.
[6] Masato Mino, Toshiaki Yachi, Akio Tago, Keiichi Yanagisawa, and Kazuhiko Sakakibara. (1992). A New Planar Micro-transformer for Use in Micro- Switching Converters. IEEE Transactions On Magnetics, vol. 28, pp. 17691973, Juillet-Août 1992. DOI: 10.1109/20.144755.
[7] Hideyuki Ito, Asako Takeuchi, Shinya Okazaki, Hiroki Kobayashi, Yuichiro Sugawa, Akihiro Takeshima, Makoto Sonehara, Nobuhiro Matsushita and Toshiro Sato. (2011). Fabrication of Planar Power Inductor for Embedded Passives in LSI Package for Hundreds Megahertz Switching DC–DC Buck Converter. IEEE Transactions On Magnetics, vol. 47, pp. 32043207. DOI: 10.1109/TMAG.2011.2147288.
[8] Ningning Wang, Santosh Kulkarni, Brice Jamieson, James Rohan, Declan Casey, Saibal Roy, Cian O’Mathuna. (2012) High Efficiency Si Integrated MicroTransformers Using Stacked Copper Windings for Power Conversion Applications. IEEE Enterprise Ireland UTIM, pp. 411-416. Doi: 10.1109/APEC.2012.6165852.
[9] Satoru Itoh, Yutaka Yamamoto, Akihiro Makino, Takashi Yamaguchi, Ichiro Sasada. (1998). A low Profile Type High Frequency Transformer Using a fine Grained Mn-Zn Ferrite. IEEE Power Electronics Specialists Conference, pp. 1492-1498. DOI: 10.1109/PESC.1998.703261.
[10] J. Y. Park, L. K. Lagorce, M. G. Allen. (1997). Ferrite Based Integrated Planar Inductors and Transformers Fabricated at Low Temperature. IEEE Transactions On Magnetics, vol. 33, N°5, September 97. DOI: 10.1109/20.617931.
[11] Dong H. Bang and Jae Y. Park. (2009). Ni-Zn Ferrite Screen Printed Power Inductors for Compact DC-DC Power Converter Applications. IEEE Transactions On Magnetics. vol. 45, pp. 2762-2765. Doi: 10.1109/TMAG.2009.2020550.
[12] K. I. Arshak, A. Ajina, D. Egan. (2001). Development of screen-printed polymer thick film planner transformer using Mn–Zn ferrite as core material. Microelectronics Journal, vol. 32, pp. 113-116. DOI: 10.1016/S0026-2692(00)00122-1.
[13] A. Mercier, K. Zehani, G. Chaplier, A. Pasko, V. Loyau and F. Mazaleyrat. (2015) SPS co-sintered monolithic transformers for power electronic. IEEE Transaction on Magnetics, vol. 4, pp. 1-4. Doi: 10.1109/TMAG.2015.2504876.
[14] Faouzi KAHLOUCHE, Youssouf KHAMIS, Mahamat hasan BECHIR, Stephane CAPRARO, Ali SIBLINI, Jean Pierre CHATELON, Cyril BUTTAY, Jean Jacques ROUSSEAU. (2014). Fabrication and characterization of a planar interleaved micro-transformer with magnetic core. Microelectronics Journal, vol. 45, pp. 893-897. https://doi.org/10.1016/j.mejo.2014.03.003
[15] Alireza Zolfaghari, Andrew Chan, and Behzad Razavi. (2000). Stacked Inductors and 1 to 2 Transformers in CMOS Technology. IEEE Custom Integrated Circuits Conference, pp. 620-628. Doi: 10.1109/CICC.2000.852681.
[16] Lei Gu and Xinxin Li. (2007). High-Performance CMOS-Compatible Solenoidal Transformers With a Concave-Suspended Configuration. IEEE Transaction on microwave theory and Techniques, vol. 55, pp. 1237-1245. Doi: 10.1109/TMTT.2007.897853.
[17] Fu Jian, Mei Niansong, Huang Yumei, and Hong Zhiliang. (2011). CMOS high linearity PA driver with an on-chip transformer for W-CDMA application. Journal of Semicondocs, vol. 32, pp. 1-6. DOI: 10.1088/1674-4926/32/9/095006.
[18] T. Mahamat, B. Danoumbé, M. Youssouf, J. P. Chatelon, S. Capraro, and J.J. Rousseau, (2016). Optimization of integrated magnetic planar transformer. IEEE Proc. Eur. Conf. Power Electron. Appl. (EPE), p 1-8, Sep. 2016. DOI: 10.1109/EPE.2016.7695386.
[19] A. Abderahim, O.B. Arafat, A. Ouzer Nabil, Y. Dagal Dari. (2021). Windings losses of planar components determination from current density. International Journal of Engineering Sciences & Research Technology. Vol. 10, No. 11, November 2021, pp. 46 – 53. http://www.ijesrt.com/November-2021.html
[20] Sunderarajan S. Mohan, Maria del Mar Hershenson, Stephen P. Boyd, and Thomas H. Lee. (1999). Simple Accurate Expressions for Planar Spiral Inductances. IEEE Journal of Solid-State Circuits, Vol. 34, NO. 10, october 1999, pp 1419-1424. DOI: 10.1109/4.792620.
[21] D. A. Oumar, M. I. Boukhari, M. A. Taha, S. Capraro, D. Piétroy, J. P. Chatelon, J. J. Rousseau. (2019). Characterization Method for Integrated Magnetic Devices at Lower Frequencies (up to 110 MHz). Journal of Electronic Testing: Theory and Applications (JETTA). https://doi.org/10.1007/s10836-019-05790-3. pp. 245 – 251.
Cite This Article
  • APA Style

    Mahamat Ahmat Taha, Mahamat Hassan Bechir, Ouzer Nabil Adam, Arafat Ousman Bechir, Boukhari Mahamat Issa, et al. (2022). Integrated Transformer with Buried Windings in Ferrite Core. Journal of Electrical and Electronic Engineering, 10(1), 10-17. https://doi.org/10.11648/j.jeee.20221001.12

    Copy | Download

    ACS Style

    Mahamat Ahmat Taha; Mahamat Hassan Bechir; Ouzer Nabil Adam; Arafat Ousman Bechir; Boukhari Mahamat Issa, et al. Integrated Transformer with Buried Windings in Ferrite Core. J. Electr. Electron. Eng. 2022, 10(1), 10-17. doi: 10.11648/j.jeee.20221001.12

    Copy | Download

    AMA Style

    Mahamat Ahmat Taha, Mahamat Hassan Bechir, Ouzer Nabil Adam, Arafat Ousman Bechir, Boukhari Mahamat Issa, et al. Integrated Transformer with Buried Windings in Ferrite Core. J Electr Electron Eng. 2022;10(1):10-17. doi: 10.11648/j.jeee.20221001.12

    Copy | Download

  • @article{10.11648/j.jeee.20221001.12,
      author = {Mahamat Ahmat Taha and Mahamat Hassan Bechir and Ouzer Nabil Adam and Arafat Ousman Bechir and Boukhari Mahamat Issa and Yaya Dagal Dari and David Pietroy and Jean Jacques Rousseau},
      title = {Integrated Transformer with Buried Windings in Ferrite Core},
      journal = {Journal of Electrical and Electronic Engineering},
      volume = {10},
      number = {1},
      pages = {10-17},
      doi = {10.11648/j.jeee.20221001.12},
      url = {https://doi.org/10.11648/j.jeee.20221001.12},
      eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.jeee.20221001.12},
      abstract = {In the field of electronics, one of the objectives of current research is to integrate numerous components in increasingly smaller volumes. Reducing the cost of manufacturing components requires integration and collective manufacturing. This paper mainly focuses on the design and the main steps of the micro-fabrication of a transformer with magnetic layers. Windings have been buried in a ferrite core by using Femtosecond Laser Micromachining. Such a burying of windings avoids air gap and greatly increases primary and secondary inductances. Different technological steps from copper deposition to the realization of the grooves in the magnetic material (in the case of the buried transformer) through etching, gilding, lapping, sawing, polishing and gluing have been described. We also used a negative photoresist (SU-8) as an insulating layer and as a support for the fabrication of an air bridge to connect the center pad of the coils to the ground plane. The micro-transformer was characterized with a Vector Network Analyzer and the bandwidth was observed from 20 kHz to 7 MHz. The gain in the bandwidth is equal to 0,86. The buried conductors allow to increase the magnetizing inductance of the transformer and the shift of 45° between the primary and secondary windings allows to decrease the capacitive coupling.},
     year = {2022}
    }
    

    Copy | Download

  • TY  - JOUR
    T1  - Integrated Transformer with Buried Windings in Ferrite Core
    AU  - Mahamat Ahmat Taha
    AU  - Mahamat Hassan Bechir
    AU  - Ouzer Nabil Adam
    AU  - Arafat Ousman Bechir
    AU  - Boukhari Mahamat Issa
    AU  - Yaya Dagal Dari
    AU  - David Pietroy
    AU  - Jean Jacques Rousseau
    Y1  - 2022/02/09
    PY  - 2022
    N1  - https://doi.org/10.11648/j.jeee.20221001.12
    DO  - 10.11648/j.jeee.20221001.12
    T2  - Journal of Electrical and Electronic Engineering
    JF  - Journal of Electrical and Electronic Engineering
    JO  - Journal of Electrical and Electronic Engineering
    SP  - 10
    EP  - 17
    PB  - Science Publishing Group
    SN  - 2329-1605
    UR  - https://doi.org/10.11648/j.jeee.20221001.12
    AB  - In the field of electronics, one of the objectives of current research is to integrate numerous components in increasingly smaller volumes. Reducing the cost of manufacturing components requires integration and collective manufacturing. This paper mainly focuses on the design and the main steps of the micro-fabrication of a transformer with magnetic layers. Windings have been buried in a ferrite core by using Femtosecond Laser Micromachining. Such a burying of windings avoids air gap and greatly increases primary and secondary inductances. Different technological steps from copper deposition to the realization of the grooves in the magnetic material (in the case of the buried transformer) through etching, gilding, lapping, sawing, polishing and gluing have been described. We also used a negative photoresist (SU-8) as an insulating layer and as a support for the fabrication of an air bridge to connect the center pad of the coils to the ground plane. The micro-transformer was characterized with a Vector Network Analyzer and the bandwidth was observed from 20 kHz to 7 MHz. The gain in the bandwidth is equal to 0,86. The buried conductors allow to increase the magnetizing inductance of the transformer and the shift of 45° between the primary and secondary windings allows to decrease the capacitive coupling.
    VL  - 10
    IS  - 1
    ER  - 

    Copy | Download

Author Information
  • Hubert Curien Laboratory, Jean Monnet University of Saint Etienne, Saint Etienne, France

  • Hubert Curien Laboratory, Jean Monnet University of Saint Etienne, Saint Etienne, France

  • Hubert Curien Laboratory, Jean Monnet University of Saint Etienne, Saint Etienne, France

  • Hubert Curien Laboratory, Jean Monnet University of Saint Etienne, Saint Etienne, France

  • Hubert Curien Laboratory, Jean Monnet University of Saint Etienne, Saint Etienne, France

  • Hubert Curien Laboratory, Jean Monnet University of Saint Etienne, Saint Etienne, France

  • Hubert Curien Laboratory, Jean Monnet University of Saint Etienne, Saint Etienne, France

  • Hubert Curien Laboratory, Jean Monnet University of Saint Etienne, Saint Etienne, France

  • Sections