Two axis magnetic camera based on AMR sensors

Summary form only given. Integrated magnetic sensors are presented. The different technological steps are described. A two-axis magnetic camera has been designed, consisting in 3/spl times/3 assembled anisotropic MR Ni/sub 83/Fe/sub 17/ thin films. These films are deposited under magnetic field on 2 inches [100] silicon wafers. Each sensor combines four resistors connected in a Wheatstone bridge. Each resistor includes three MR tapes 0.05 /spl mu/m thick, 500 /spl mu/m long and 10 /spl mu/m wide. In order to obtain a linear response of the magnetic sensor, the so-called barber pole biasing technique is used. The obtained sensing range and sensitivity are respectively 2 kA/m and 3 /spl mu/V/A.m/sup -1/. The advantages of this magnetic camera rest in: (a) the integration of nine bidirectional detectors on 0.25 cm/sup 2/ area, (b) the measurement of the surface magnetic field in electrical sheets.