Using Peacock Shape Anisotropic Magnetoresistance (AMR) and Ni Mushroom Array to Achieve Tri-Axis Magnetic Sensor

Abstract

This study extends the concept of magnetic sensor with flux guide structure to demonstrate a novel tri-axis magnetic sensing chip design. The tri-axis anisotropic magneto-resistive (AMR) sensor consists of two existing pure AMR film routing for in-plane magnetic field sensing and a novel peacock shape routing with a mushroom shape structure array as magnetic flux guide to enhance the out-of-plane magnetic field detection. Due to the radial symmetry design, the peacock shape AMR film has similar sensing signals introduced by the in-plane magnetic field of different azimuths. Thus, the decouple of the out-of-plane and in-plane sensing signals is easily achieved. Measurements demonstrate that the proposed peacock shape AMR film has no resistance variation when exposed to in-plane magnetic field of different azimuths, and could detect the out-of-plane magnetic flux collected by the Ni-pillar. The sensitivity of AMR ratio in out-of-plane is -2×10-4 %/Gauss.