Manufacturing of flexible (ultra-)thin magnetic field sensors

Several applications require (ultra-)thin and reliable packaging of the sensor electronics. Especially the rapidly increasing use of sensor elements in nearly every field of engineering is the main driver for that fact. One specific application is magnetic field sensors in active magnetic bearings. In order to improve their precision and stiffness those bearings can be beneficially operated by measuring the magnetic flux inside the air gap in between the curved stator and rotor components. To achieve proper and reliable sensor integration, both the sensor elements and the packaging have to meet the requirements concerning total height and bendability. Therefore the maximum sensor thickness must not exceed 200 mu m. For the reliable mounting of the sensor onto the stator pole it is also necessary, that those sensors have to be bendable down to radii of 25 mm. As a consequence the sensor package needs to be flexible as well.