Integrated thin film magneto-impedance sensor head using plating process

An integrated thin film MI(magneto-impedance) sensor head constructed with a combination of a thin film NiFe MI element and thin film bias and negativ e feedback coils sing a micro-plating technology, has been developed in ord er to solve the problems of an amorphous wire MI head. The sensor head show ed a very high field-detection sensitivity of about 0.41%/A/m(33%/Oe) magne tized with pulse current and a small hysteresis for the change of an extern al field. We have fabricated a differential type sensor module using a pair of the thin film MI sensor heads. The output voltage of the sensor has a g ood linearity within the range of +/- 80A/m, and the voltage was 25mV/A/m(2 .0V/Oe), and has small thermal drift within 0.1A/m/degrees C. The consumpti on power of the sensor module was 165mW.