WO2006134520A1

WO2006134520A1 - Magnetic field sensor device

Info

Publication number: WO2006134520A1
Application number: PCT/IB2006/051826
Authority: WO
Inventors: Torsten Philipp
Original assignee: Nxp B.V.
Priority date: 2005-06-13
Filing date: 2006-06-08
Publication date: 2006-12-21

Abstract

The invention relates to a magnetic field sensor device for measuring three components of a magnetic field comprising a magneto-resistive first planar sensor (5+6) sensitive to two components of the magnetic field in the plane of the first planar sensor and a second planar sensor (2) mounted parallel to the first planar sensor sensitive to a third component of the magnetic field perpendicular to the plane of the second planar sensor. Further the invention relates to a method for producing such a device.

Description

MAGNETIC FIELD SENSOR DEVICE

The invention relates to a magnetic field sensor device for measuring three components of a magnetic field and a method for manufacturing the device.

Three-dimensional magnetic field sensors can be used with compasses especially for navigation systems. Such sensor devices shall be easily to be manufactured.

US 6,278,271 Bl discloses a three-dimensional magnetic field sensor with a hall effect element mounted on a substrate. This sensor comprises a monolithic hall effect element which is used to measure all three magnetic components according to the principle of determinating the distribution of the magnetic flux in the quadrants of the area of the hall effective element by calculating and evaluating sum and difference signals from four measuring directions.

An object of the invention is to measure the magnetic field directly with a planar sensor device. A further object of the invention is a sensor device which is capable for compact and rigid equipment. The sensor device according to the invention comprises a magneto-resistive first planar sensor sensitive to two components of the magnetic field in the plane of the first planar sensor and a second planar sensor mounted parallel to the first planar sensor sensitive to a third component of the magnetic field perpendicular to the plane of the second planar sensor. In a preferred embodiment of the invention the first planar sensor comprises two magneto-resistive elements arranged side by side in one plane and being sensitive to said two components each within two directions. Preferably the second planar sensor is a hall element. Further improvements and preferred embodiments of the inventive sensor device are closed in further claims.

The invention further relates to a method for producing a magnetic field measuring device comprising a magneto-resistive first planar sensor sensitive to two components of the magnetic field in the plane of the first planar sensor and a second planar sensor mounted parallel to the first planar sensor sensitive to a third component of the magnetic field perpendicular to the plane of the second planar sensor, comprising the steps of - structuring the second planar sensor out-of a semi conducting layer substrate, depositing an electrical insolating second layer, and building the first planar sensor on the electrical insolating layer. Preferably the first planar sensor comprises two magneto-resistive elements arranged side by side in one plane and being sensitive to said two components each within two directions and/or the second planar sensor is a hall element.

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

Fig. 1 is a view upon a first embodiment of the invention,

Fig. 2 shows a section through the embodiment according to figure 1 at the line AA,

Fig. 3 shows a section through a second embodiment, and Fig. 4 shows a section through a third embodiment.

The first embodiment according to figures 1 and 2 comprises a substrate 1 with an integrated hall element 2. Two layers 3, 4 are insolating layers. On the surface of the first insolating layer 3 two magneto-resistive elements 5, 6 are formed. Each of the magneto-resistive elements 5, 6 has a different direction of sensitivity.

A part of the surface of the substrate 1 is structured as integrated circuit 9 for the operation of the hall element 2 and the magneto-resistive elements 5, 6. Both are connected with the integrated circuit 9 by conductors 10. Fig. 2 shows only some of the conductors 10. For protection purpose the device is covered by an insolating protection layer 11.

The embodiment according to Fig. 3 has two substrates 12, 13. The substrate 12 bears the hall element 2 insolating layers 3, conductors 10 through platings and an integrated circuit 9.

The substrate 13 carries on an insolating area 14 a magneto-resistive sensor element 15. The details of which can be realized as the magneto-resistive sensor shown in figures 1 and 2. Both sensors are connected by solder ball contacts 16. The space 17 between both sensors can be filled by a suitable material. The embodiment according to Fig. 4 has also two sensors being built on two substrates 12, 18. The sensors are electrically connected by bond wires 19.

Claims

CLAIMS:

1. A magnetic field sensor device for measuring three components of a magnetic field comprising a magneto-resistive first planar sensor (5, 6) sensitive to two components of the magnetic field in the plane of the first planar sensor (5, 6; 15) and - a second planar sensor (2) mounted parallel to the first planar sensor (5,

6; 15) sensitive to a third component of the magnetic field perpendicular to the plane of the second planar sensor (2).

2. A device according to claim 1, wherein the first planar sensor comprises two magneto-resistive elements (5, 6) arranged side by side in one plane and being sensitive to said two components each within two directions.

3. A device according to one of the claims 1 or 2, wherein the second planar sensor is a hall element (2).

4. A device according to one of the preceding claims, wherein the first planar sensor (5, 6) and the second planar sensor (2) are built in different layers on a common substrate (1).

5. A device according to claim 4, wherein the common substrate (1) further bears an integrated circuit (9).

6. A device according to one of the claims 1 to 3, wherein each planar sensor is built on a separate substrate (12, 13, 18).

7. A device according to claim 6, wherein the planar sensors (12, 13) are connected by solder ball contacts (16).

8. A device according to claim 6, wherein the planar sensors (12, 18) are connected by bond wires (19).

9. A device according to one of the claims 6 to 8, wherein at least one of the substrates (12, 13, 18) further bears an integrated circuit (9).

10. Method for producing a magnetic field sensor device for measuring three components of a magnetic field comprising a magneto-resistive first planar sensor sensitive to two components of the magnetic field in the plane of the first planar sensor and a second planar sensor mounted parallel to the first planar sensor sensitive to a third component of the magnetic field perpendicular to the plane of the second planar sensor, comprising the steps of structuring the second planar sensor out-of a semi conducting layer substrate, - depositing an electrical insolating second layer, and building the first planar sensor on the electrical insolating layer.

11. Method according to claim 10, wherein the first planar sensor comprises four magneto-resistive elements arranged side by side in one plane and being sensitive to said two components each within two directions.

12. Method according to one of the claims 10 or 11, wherein the second planar sensor is a hall element.