Change the Magnetic Properties of Electroplated Core Films to Improve Micro-Fluxgate Performance

It is very important for micro-fluxgate to reduce its power consumption because higher power consumption causing serious cooling problem which will lead series of questions. In this paper the influence of core film magnetic properties (coercive force Hc and saturation field Hs) on optimum excitation current (OEC) and sensitivity are investigated theoretically. The expressions of optimum excitation magnetic and maximum sensitivity were given. In the field of magnetic material, lower Hc means better soft magnetic properties, but when analyze the effect of Hs and Hc on the OEC and corresponded sensitivity we find that low Hs and high Hc bring low OEC and high sensitivity. Applied magnetic fields at different angles during electroplating and annealing are introduced to improve magnetic properties of electroplated core films. In subsequent experiment we test the OEC, sensitivity, linear range and magnetic noise of fluxgate utilize these core films. Plating with θ=0° (θ is the angle between applied magnetic field and long edge of the core) samples obtain lowest OEC and highest sensitivity, plating with θ=90° and annealed samples obtain large linear range, annealed samples obtain lowest magnetic noise.