3-D magnetic sensor

Patent metadata

Field	Value
Publication number	US-9513344-B2
Application number	US-201514676010-A
Country	US
Kind code	B2
Filing date	Apr 1, 2015
Priority date	Feb 28, 2011
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

One embodiment of the present invention relates to a magnetic field sensor having a squat soft-magnetic body disposed on a surface of a substrate including a magnetic sensor array having a plurality of spatially diverse magnetic sensor elements disposed in a predetermined configuration. In the presence of an external magnetic field the squat soft-magnetic body becomes magnetized to generate a reactionary magnetic field. The plurality of magnetic sensor elements respectively measure a magnetic field value of a superposition of the external magnetic field and the reactionary magnetic field along a first axis (e.g., a z-axis), resulting in a plurality of spatially diverse measurements of the magnetic field component along the first axis. The plurality of spatially diverse measurements may be used to compute magnetic field components of the external magnetic field along a plurality of axes (e.g., x-axis, y-axis, and z-axis).

First claim

What is claimed is:

1. A magnetic field sensor, comprising:
a semiconductor die;
a squat soft-magnetic body comprising a soft magnetic material having a non-planar surface facing the semiconductor die, wherein in the presence of an external magnetic field the squat soft-magnetic body is configured to generate a reactionary magnetic field and wherein the semiconductor die laterally extends past the squat soft-magnetic body; and
a plurality of magnetic sensor elements arranged within or on the semiconductor die at discrete locations, wherein the non-planar surface is closest to the semiconductor die at a point centered between the plurality of magnetic sensor elements.

2. The magnetic field sensor of claim 1 , wherein the plurality of magnetic sensor elements are symmetric about a center of the squat soft-magnetic body along a first direction and along a second perpendicular direction.

3. The magnetic field sensor of claim 1 , wherein the squat soft-magnetic body continuously extends from a first position overlying a first one of the plurality of magnetic sensor elements to a second position overlying a second one of the plurality of magnetic sensor elements, so that the first one of the plurality of magnetic sensor elements and the second one of the plurality of magnetic sensor elements are arranged between the semiconductor die and the squat soft-magnetic body.

4. The magnetic field sensor of claim 3 , wherein the plurality of magnetic sensor elements further comprise a third magnetic sensor element arranged along a first line that is perpendicular to a second line extending through the first one of the plurality of magnetic sensor elements and the second one of the plurality of magnetic sensor elements.

5. The magnetic field sensor of claim 1 , wherein the squat soft-magnetic body consists of a squat magnetic material having a curved lower surface facing the semiconductor die.

6. The magnetic field sensor of claim 1 , wherein the squat soft-magnetic body is arranged completely over the semiconductor die and has a circular cross-section.

7. The magnetic field sensor of claim 6 , further comprising:
a gap layer that is vertically arranged between the squat soft-magnetic body and the semiconductor die, wherein the gap layer has a planar surface directly contacting the squat soft-magnetic body.

8. The magnetic field sensor of claim 6 , wherein the squat soft-magnetic body is attached to a leadframe package containing the semiconductor die.

9. The magnetic field sensor of claim 1 , further comprising:
a glass layer bonded to the semiconductor die and comprising at least one hole or recess located in proximity to the plurality of magnetic sensor elements, wherein the squat soft-magnetic body is comprised at least partly within the hole.

10. The magnetic field sensor of claim 1 , wherein the squat soft-magnetic body is arranged completely over the semiconductor die and is symmetric about a first plane that is parallel with an upper surface of the semiconductor die and about a second plane that is perpendicular the upper surface of the semiconductor die.

11. A magnetic field sensor, comprising:
a semiconductor die;
a squat soft-magnetic body comprising a soft magnetic material having a circular cross-section that is completely disposed over the semiconductor die, wherein the semiconductor die extends laterally past the squat soft-magnetic body;
a plurality of magnetic sensors vertically spaced apart from the squat soft-magnetic body and arranged within or on the semiconductor die at discrete locations that are symmetric about a center of the squat soft-magnetic body; and
wherein the soft magnetic material has a non-planar surface that faces the semiconductor die and that is closest to the semiconductor die at a point centered between the plurality of magnetic sensors.

12. The magnetic field sensor of claim 11 , wherein the squat soft-magnetic body is arranged completely over the semiconductor die and is symmetric about a first plane that is parallel with an upper surface of the semiconductor die and about a second plane that is perpendicular the upper surface of the semiconductor die.

13. The magnetic field sensor of claim 11 ,
wherein the plurality of magnetic sensors comprise a first magnetic sensor and a second magnetic sensor that are separated by a space over which the squat soft-magnetic body is disposed; and
wherein the plurality of magnetic sensors further comprise a third magnetic sensor arranged along a first line that is perpendicular to a second line extending through the first magnetic sensor and the second magnetic sensor.

14. The magnetic field sensor of claim 11 , wherein the squat soft-magnetic body consists of a soft magnetic material.

15. A magnetic field sensor, comprising:
a semiconductor substrate;
a squat soft-magnetic body comprising a soft magnetic material disposed completely over the semiconductor substrate, wherein the soft magnetic material has a non-planar surface facing the semiconductor substrate;
a plurality of magnetic sensor elements vertically spaced apart from the squat soft-magnetic body and arranged within or on the semiconductor substrate at discrete locations arranged around a center of the squat soft-magnetic body; and
wherein the squat soft-magnetic body is symmetric about a first plane that is parallel with an upper surface of the semiconductor substrate and about a second plane that is perpendicular the upper surface of the semiconductor substrate.

16. The magnetic field sensor of claim 15 , wherein the squat soft-magnetic body comprises a cylinder having an axis that extends in a direction that is parallel to the upper surface of the semiconductor substrate.

17. The magnetic field sensor of claim 15 , further comprising:
a gap layer that is vertically arranged between the squat soft-magnetic body and the semiconductor substrate, wherein the gap layer has a planar surface directly contacting the squat soft-magnetic body.

18. The magnetic field sensor of claim 17 , further comprising:
a glass layer arranged between the gap layer and the squat soft-magnetic body, wherein the squat soft-magnetic body is arranged within a recess in the glass layer.

19. The magnetic field sensor of claim 11 , wherein the plurality of magnetic sensors comprise a first magnetic sensor arranged directly vertically below the center of the squat soft-magnetic body and two or more additional magnetic sensors that are laterally separated from the first magnetic sensor and that are symmetric about the center of the squat soft-magnetic body.

Assignees

• Infineon Technologies Ag

Inventors

• Ausserlechner Udo

Classifications

• H01L43/06

  Electricity · mapped topic

• H01L43/08

  Electricity · mapped topic

• G01R33/0206 Primary

  Three-component magnetometers · CPC title

• G01R33/077

  Vertical Hall-effect devices · CPC title

• G01R33/09

  Magnetoresistive devices · CPC title