Customized GMR-spin valve sensors for low field applications

We report on new GMR spin valve sensors for the measurement of low magnetic fields. The sensors are designed as Wheatstone bridges with different locally impressed magnetic reference directions. The method of impressing magnetic reference directions has been recently established in the wafer-production of HL Planartechnik. The key is a local annealing of every sensor element by current pulses through the element itself. The flexibility of the annealing process enables HL Planartechnik to easily adapt a single GMR field sensor type to the special requirements of various applications. We will present our new sensor series which is used for speed measurement, Earth's field detection, magnetic code reading, and many further applications.