New hybrid technology for planar fluxgate sensor fabrication

Abstract

Abstract-We have adapted a new printed circuit board (PCB) technology to the fabrication of ultraflat and sensitive fluxgate magnetic field sensors. The two outer layers of the PCB stack compose the electrical windings of fluxgates, while the inner layer is made of a micro-patterned amorphous magnetic ribbon with extremely high relative magnetic permeability ( r 100 000).Two basic configurations were considered: one based on a toroidal magnetic core and the other on a rectangular core with and without an air gap. The field response and sensitivity of the fluxgate devices have been studied as a function of the gap length, the excitation current, and excitation frequency. Compared to fluxgate sensors of similar size, a relatively high sensitivity of 60 V/T was found at 30 kHz for a five-winding detection coil wound around a rectangular E-shaped magnetic core. This high performance is primarily attributable to the high-permeability magnetic core. The results clearly show the potential of this fluxgate device for application as a magnetic sensor.

Hybrid ferrite-amorphous planar fluxgate

“…A maximum sensitivity of 12.7 V/T at 50 kHz has been obtained, similar to those reported by other authors [6][7][8], having into account the low driving frequency and the small number of turns used in this sensor. However, the minimum detectable field is 80 nT, better than those found in the above mentioned references.…”

Fabrication Advancements in Integrated Fluxgate Sensors: A Mini Review

“…[106] Olivier Dezuari et al fabricated a fluxgate sensor on the PCB, and accomplished it with the ring core in 1999. [104] Perez et al designed a new 2D fluxgate sensor with two PCB wafers. The spiral pattern on the wafers was produced in the outer and inner parts of the double-sided board, copper rings were deposited using electroplating, and the external coil and internal coils were connected using copper wires (Figure 24).…”

Small Fluxgate Magnetometers: Development and Future Trends in Spain

“…At the beginning of the 21th century, the research in fluxgate sensors at GDM moves slowly to the second approach: miniaturization of the coils surrounding the ferromagnetic core. In the late 90's, the group of Prof. Martin Gijs at Ecole Polytechnique Fédérale de Lausanne proposed the use of Printed Circuit Board (PCB) Technology for the planarization and integration of fluxgate sensors [ 16 , 17 ]. The windings were made in PCB boards, the ferromagnetic core sandwiched between the boards and, in the last step, the boards are contacted to make a coil surrounding the core.…”

“…This implies that any problem with the winding due to the miniaturization of the device has been completely overcome. As previously stated, this was achieved by micromachining the winding using PCB technology like done by Prof. Gijs [ 16 , 17 ].…”