PURPOSE: To reduce an exclusive area for a signal processing circuits of magnetoresistance elements and a bias magnetic field and to make an apparatus compact and light, by providing the magnetoresistance elements and conductor patterns on a substrate incorporating a magnetic conductor for forming the bias magnetic field.
CONSTITUTION: Magnetoresistance elements 11 are barber-pole type magnetoresistance elements utilizing a ferromagnetic thin film such as Permalloy or a pair of magnetoresistance elements utilizing the Hall effect of a semiconductor element. A substrate 12 is constituted by laminating the following materials: an insulating layer 22 of a heat oxide film or the like having insulating property; an aluminum material 211 having good heat conductivity as a heat radiating layer 21; and a ferrite material 200 that is thinly formed magnetic body 20. Conductor patterns 13 are signal processing circuits 131 of the magnetoresistance elements 11 comprising the following parts: a voltage amplifier for amplifying the changing part of magnetoresistance; its protecting circuit; a comparing and operating circuit for comparing a known amount and an amount to be measured; and the like. In this way, a magnetism detector can be made compact and light. Initial magnetization is made possible for a thinly formed magnetic body. An external magnetic field is fixed, and a desired bias magnetic field can be obtained.
SHIMIZU SHINKICHI
WAKATSUKI NOBORU
