MEMS micro fluxgate sensors with mutual vertical excitation coils and detection coils

作者：Lei, Chong^*; Wang, Ren; Zhou, Yong; Zhou, Zhimin

来源：Microsystem Technologies, 2009, 15(7): 969-972.

DOI：10.1007/s00542-009-0847-9

• Earth magnetic fields
• Excitation currents
• Fabricated sensors
• Micro-fluxgate sensors
• Operational frequency
• Rectangular-shaped
• Second harmonic signals
• Vertical excitation

As a classic Earth magnetic field sensor, fluxgate magnetic sensors have great potential applications in many fields. This paper presents a new 3D micro-solenoid fluxgate magnetic sensor based on the MEMS technique. The excitation coils were placed vertically to the detection coils on the chip plane, around a rectangular shaped magnetic core. Polyimide was used to insulate coils and magnetic core. Width of copper conductor lines is 50 mu m, and line space is 50 mu m. The design of such fluxgate magnetic sensor followed second harmonic signal selecting method. Phase-lock amplifier was used to get second harmonic signal output by detection coils. The linear range of 0-80 mu T with sensitivity of 6.7 V/T was achieved from the fabricated sensor with excitation current of 430 mA and the operational frequency of 40 KHz. As the excitation current was 470 mA, linear range of 0-50 mu T with sensitivity of 21.7 V/T was achieved.

• 出版日期2009-7
• 单位上海交通大学