A Micro Fluxgate Magnetic Sensor Using Micromachined 3-Dimensional Planar Coils

Abstract

A new micro fluxgate magnetic sensor using micromachined 3-dimensional solenoid coils has been designed, fabricated, and characterized in this work. The fluxgate sensor adopts a ring-type shape and second-harmonic principle, and is composed of exciting coils, a ring core, and sensing coils. Using a newly developed UV lithography-based thick photoresist process and electroplating techniques, planar three-dimensional magnetic fluxgate sensors were fabricated on a silicon wafer. The measured sensor output shows excellent linear characteristics over the range of ±500 µT with a resolution of approximately 60 nT, achieving the sensitivity of 8360 VT 1 • Furthermore, this sensor also shows a wide sensing range of ± 1.5 mT. Using this highly sensitive, on-chip fluxgate sensor, various applications are expected from space research to portable navigation systems.

Characterization of Ni x Fe1 − x ( 0.10 < x < 0.95 ) Electrodeposition from a Family of Sulfamate‐Chloride Electrolytes

“…In the fabrication of NiFe microstructures by deposition through patterned molds, for instance, the desired alloy composition is often quite specific, such as Permalloy or Invar. [5][6][7][8][9] In general, plating uniform NiFe microstructures is challenging due to unavoidable and significant variations in current density and electrolyte mixing across the patterned cathode. [31][32][33][34] While the extent of current variations and mixing nonuniformities can often be minimized, these nonuniformities nearly always exist.…”

“…For example, many magnetic microactuators and inductors such as solenoids, valves, and cantilevers are fabricated using electrodeposited Permalloy. [5][6][7][8] In addition, electrodeposited Invar structures have been studied for use as servo actuators for magnetic recording heads, an application in which dimensional stability over a wide temperature range is required. 9 The magnetic, mechanical, and corrosion properties of NiFe electrodeposits are dictated by a number of factors including metallurgical structure (e.g., grain size, growth orientation) and alloy composition.…”

Electromagnetic Actuator for Laser Beam Positioning – Manufacturing Process

“…In addition, the properties of the materials can be "adapted" by controlling the solution compositions and deposition parameters [17][18]. The magnetic thin films have good adhesion, are resistant to corrosion and are thermally stable with excellent magnetic properties.…”