Transactions on Electrical and Electronic Materials

The Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회)
권호 표지
DOI QR코드

DOI QR Code

High Sensitivity Micro-fabricated Fluxgate Sensor with a Racetrack Shaped Magnetic Core

  • Choi, Won-Youl (Department of Metal and Materials Engineering, Kangnung National University) ;
  • Kim, So-Jung (Department of Electrical and Electronic Engineering, Donghae University)
  • Published : 2005.06.01
Download PDF
⟨ Previous Next ⟩

Abstract

We present a micro fluxgate magnetic sensor having solenoid coils and racetrack shaped magnetic core, which was designed to decrease the .operating power and magnetic flux leakage. Electroplated copper coils of $6\;{\mu}m$ thickness and the core of $3\;{\mu}m$ thickness were separated by benzocyclobutane (BCB) having a high insulation and good planarization characters. Permalloy $(Ni_{0.8}Fe_{0.2})$ as a magnetic core was also electroplated under 2000 gauss to induce the magnetic anisotropy. The core had the high DC effective permeability of $\~1,300$ and coercive field of $\~0.1$ Oe. The fabricated fluxgate sensor had the very small actual size of $3.0\times1.7\;mm^2$. The fluxgate sensor with a racetrack shaped core had the high sensitivity .of $\~350$ V/T at excitation condition of 3 $V_{P-P}$ and 2 MHz square wave. When two fluxgates were perpendicularly aligned in terrestrial field, their two-axis output signals were very useful to commercialize an electronic azimuth compass for the portable navigation system.

Keywords

References

  1. F. Primdahl, 'The fluxgate magnetometer', J. Phys. E: Sci. Instrum., Vol. 12, p. 241, 1979
  2. P. Ripka, 'Review of fluxgate sensors', Sensors and Actuators A, Vol. 33, p. 129, 1992
  3. P. Ripka, M. Tondra, J. Stokes, and R. Beech, 'ACdriven AMR and GMR magnetoresistors', Proc. Eurosensors XII, p. 967, 1998
  4. S. Kawahito, H. Sato, M. Sutoh, and Y. Tadokoro, 'High-resolution micro fluxgate sensing elements using closely coupled coil structures', Sensors and Actuators A, Vol. 54, p. 612, 1996
  5. S. Choi, S. Kawahito, K. Takahashi, Y. Matsumato, M. Ishida, and Y. Tadokoro, 'A planar fluxgate magnetic sensor for on-chip integration', Sensors and Materials, Vol. 9, No.4, p. 241, 1997
  6. R. Gottfried-Gottfried, W. Budde, R. Jahne, H. Kuck, B. Sauer, S. Ulbricht, and U. Wende, 'A miniaturized magnetic field sensor system consisting of a planar fluxgate sensor and a CMOS readout circuitry', Transducers95, Eurosensor IX, p. 229, 1995
  7. T. Liakopoulos and C. Ahn, 'A micro-fluxgate magnetic sensor using micromachined planar solenoid coils', Sensors and Actuators A, Vol. 77, p. 66, 1999
  8. P. Robertson, 'Microfabricated fluxgate sensors with low noise and wide bandwidth', Electronics Letters, Vol. 36, No.4, p. 331, 2000 https://doi.org/10.1049/el:20001418
  9. K.-W. Na, H.-S. Park, D.-S. Shim, W.-Y. Choi, J.-S. Hwang, and S.-O. Choi, 'MEMS-based micro fluxgate sensor using solenoid excitation and pickup coils', J. of KIEEME(in Korean), Vol. 16, No.2, p. 120, 2003
  10. H.-S. Park, J.-S. Hwang, W.-Y. Choi, D.-S. Shim, K.-W. Na, and S.-O. Choi, 'Development of microfluxgate sensors with electroplated magnetic cores for electronic compass', Sensors and actuators A Physical, Vol. 114, No. 2/3, p. 224, 2004
  11. T. Seitz, 'Fluxgate sensor in planar microtechnology', Sensors and Actuators A, Vol. 21, p. 799,1990