THIN-FILM MAGNETIC FIELD SENSOR

摘要

There is provided a thin-film magnetic field sensor, which has a simple structure and a high detecting sensitivity, and reduces measurement errors due to temperature variation or the like. In the thin-film magnetic field sensor according to the present invention, two arms of a bridge circuit are formed of an element 5 having a giant-magneto-resistant thin-film, and soft magnetic thin-films disposed one on either side thereof, with electrical terminals, and an element 10 having a giant-magneto-resistant thin-film, and conductive films disposed one on either side thereof, with electrical terminals. The electrical resistance value of the element 10 has sensitivity relative to the magnetic field, such that it is substantially zero when the magnetic field is small, but it changes equally to the element 5 due to causes other than the magnetic field. Since the output of the bridge circuit is in proportion to the difference in electrical resistance values between the elements 5 and 10, part of a change due to causes other than the magnetic field is canceled in the output of the bridge circuit, whereby the magnetic field value can be accurately measured.