Packaging technologies for (Ultra-)thin sensor applications in active magnetic bearings

We realized ultra-thin and flexible magnetic field sensors based on the Hall Effect in 2 μm thick Bismuth films prepared on commercial flexible double-layer polyimide PCB with a total thickness of 150 μm. These sensors could be potentially applied in active magnetic bearing (AMB) systems. Therefore, here we address reliability aspects of flexible Hall sensors with emphasis on the proper choice of adhesive to mount the sensor to a stator of the AMB. The thermal shock tests in the standard automotive temperature range of -40°C to 165°C as well as the vibration test of the sensor mounted to the stator has proven the sensor´s stability.