Abstract:
It is described a magnetic field differential sensor system for measuring rotational movements of a shaft. The described magnetic field sensor system (200) comprises (a) a biasing magnet (210, 510) configured for generating a biasing magnetic field; (b) a magnetic wheel (230) having a wheel axis and a circumferential surface which comprises a regular structure of teeth (231) and gaps (232) arranged in an alternating manner, wherein (i) the magnetic wheel (230) is attachable to the shaft and (ii) the magnetic wheel (230) can be magnetized by the biasing magnetic field; and (c) a magnetic sensor arrangement (220) comprising four magnetic sensor elements (221, 222, 223, 224) being connected with each other in a Wheatstone bridge configuration. Respectively two of the magnetic sensor elements (221, 222, 223, 224) are assigned to one half bridge of the Wheatstone bridge. Further, the four magnetic sensor elements (221, 222, 223, 224) are arranged within an y-z plane, wherein an x-axis, a y-axis and a z-axis define an orthogonal Cartesian coordinate system in which (i) the x-axis is oriented parallel with the wheel axis of the magnetic wheel (230), (ii) the y-axis is oriented tangential to the circumferential surface of the magnetic wheel (230), and (iii) the z-axis is the symmetry line through the center of the biasing magnet (210, 510) and the center of the magnetic wheel (230). The magnetic sensor elements can be hall sensor elements or magnetoresistive sensor elements (221, 222, 223, 224).
Abstract:
A method is described for manufacturing a magnetic sensor module (100, 200, 300, 400) having magnetic sensor elements (130, 330, 430) monolithically integrated at a semiconductor chip (110) which comprises an integrated circuit. The described method comprises (a) providing a composite semiconductor arrangement (105) comprising (i) the semiconductor chip (110), (ii) contact elements (112) for the integrated circuit, which are formed on the semiconductor chip (110), and (iii) a dielectric layer (120) formed over the semiconductor chip (110) and over the contact elements (112), (b) forming a magnetic sensor layer providing the material for the magnetic sensor elements (130, 330, 430) monolithically over the dielectric layer (120), (c) exposing the contact elements (112) by removing a part of the dielectric layer (120) which part is located above the contact elements (112), and (d) forming an electric conductive protection layer (140, 240, 340, 440) over either the formed magnetic sensor layer or the exposed contact elements (112) in order to prevent negative interactions between (i) the step of forming the magnetic sensor elements (130, 330, 430) resulting from the magnetic sensor layer and (ii) the step of exposing the contacting elements (112). It is further described a magnetic sensor module (100, 200, 300, 400) which is manufactured by the above described method.
Abstract:
A method is described for manufacturing a magnetic sensor module (100, 200, 300, 400) having magnetic sensor elements (130, 330, 430) monolithically integrated at a semiconductor chip (110) which comprises an integrated circuit. The described method comprises (a) providing a composite semiconductor arrangement (105) comprising (i) the semiconductor chip (110), (ii) contact elements (112) for the integrated circuit, which are formed on the semiconductor chip (110), and (iii) a dielectric layer (120) formed over the semiconductor chip (110) and over the contact elements (112), (b) forming a magnetic sensor layer providing the material for the magnetic sensor elements (130, 330, 430) monolithically over the dielectric layer (120), (c) exposing the contact elements (112) by removing a part of the dielectric layer (120) which part is located above the contact elements (112), and (d) forming an electric conductive protection layer (140, 240, 340, 440) over either the formed magnetic sensor layer or the exposed contact elements (112) in order to prevent negative interactions between (i) the step of forming the magnetic sensor elements (130, 330, 430) resulting from the magnetic sensor layer and (ii) the step of exposing the contacting elements (112). It is further described a magnetic sensor module (100, 200, 300, 400) which is manufactured by the above described method.
Abstract:
A magnetic field sensor system for measuring rotational movements of a shaft is disclosed. The sensor system includes a biasing magnet configured for generating a biasing magnetic field and a magnetic wheel having a wheel axis and a circumferential surface which comprises a regular structure of teeth and gaps arranged in an alternating manner. The magnetic wheel is attachable to the shaft and is magnetizable by the biasing magnetic field. A magnetoresistive sensor arrangement comprising four magnetoresistive sensor elements being connected with each other in a Wheatstone bridge, respectively two of the magnetoresistive sensor elements being assigned to one half bridge of the Wheatstone bridge. The four magnetoresistive sensor elements are arranged within an x-y plane.