Magnetic field sensor having deformable conductor loop segment

• US 6,486,665 B1
• Filed: 11/21/2000
• Issued: 11/26/2002
• Est. Priority Date: 03/06/1998
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Funk, Karsten, Frey, Wilhelm
• Primary Examiner(s): Le, N.
• Assistant Examiner(s): Deb, Anjan K.
• Application Number:
  US09/623,670
• Time in Patent Office: 735 Days
• Field of Search: 324/239, 324/179, 324/207.11, 324/207.15, 324/207.17, 324/750, 324/260, 333/197, 310/309, 336/20
• US Class Current: 324/260
• CPC Class Codes: G01R 33/0283 in which a current or voltage is generated due to relative movement of conductor and magnetic field
• CPC Class Codes: G01R 33/0286 comprising microelectromechanical systems [MEMS] MEMS devices in general B81B

Abstract

A magnetic field sensor that can be manufactured using the technology of surface micromechanics, having a conductor loop that has at least one deformable segment; a deformation device for deforming the deformable segment of the conductor loop with a predeterminable time dependence; a voltage sensing device for sensing the voltage induced at the ends of the conductor loop upon deformation in the presence of a magnetic field; and a magnetic field determining device for determining the present static and/or dynamic magnetic field in consideration of at least the time dependence of the deformation.

Claims

1. A magnetic field sensor, comprising:

a conductor loop including at least one deformable segment;

a deformation device for deforming the at least one deformable segment of the conductor loop with a predeterminable time dependence;

a voltage sensing device for sensing a voltage induced at ends of the conductor loop upon deformation in a presence of a magnetic field; and

a magnetic field determining device for determining the magnetic field when the magnetic field is in at least one of a present static state and a present dynamic state in consideration of at least the time dependence of the deformation, wherein;

the deformation device deforms the at least one deformable segment by generating electrostatic attractive forces via a capacitive coupling.

3. The magnetic field sensor according to claim 1 wherein:

in an undeformed state the conductor loop encloses an area bounded by two longitudinal sides of the conductor loop that are substantially parallel to one another, and

the deformation device deforms the two longitudinal sides to change the enclosed area.

4. The magnetic field sensor according to claim 3, wherein:

the deformation device excites the two longitudinal sides to opposite-direction resonant flexural oscillations.

5. The magnetic field sensor according to claim 4, herein:

the conductor loop is configured such that the opposite-direction resonant flexural oscillations have a different resonant frequency from corresponding same-direction resonant flexural oscillations.

6. The magnetic field sensor according to claim 3, further comprising:

a substrate above which are floatingly arranged the two longitudinal sides of the conductor loop and on which are floatingly mounted widthwise sides of the conductor loop, wherein;

the conductor loop has a substantially rectangular shape, and

the two longitudinal sides are deformable by the deformation device.

7. The magnetic field sensor according to claim 6, wherein:

the substrate includes silicon.

8. The magnetic field sensor according to claim 6, further comprising:

at least one connector pad anchored in the substrate; and

at least one deformable floating strut having a thickness that substantially corresponds to a thickness of the two longitudinal sides and via which a continuous, nondeformable one of the widthwise sides is connected to the at least one connector pad, wherein;

the continuous, nondeformable widthwise side has a greater thickness than that of the two longitudinal sides.

9. The magnetic field sensor according to claim 8, wherein:

another one of the widthwise sides corresponds to a split, nondeformable second widthwise side having a greater thickness than that of the two longitudinal sides and having parts each connected via a respective one of the at least one deformable floating strut to a respective one of the at least one connector pad.

10. The magnetic field sensor according to claim 8, further comprising:

a deformable floating first resilient strut, wherein;

a first end of respective ones of the two longitudinal sides are each connected via the deformable floating first resilient strut to the at least one connector pad, and

the deformable floating first resilient strut has a thickness that is substantially that of the two longitudinal sides.

11. The magnetic field sensor according to claim 8, further comprising:

a deformable floating second resilient strut, wherein;

a second end of respective ones of the two longitudinal sides are each connected via the deformable floating second resilient strut to the continuous, nondeformable widthwise side, and

the deformable floating second resilient strut has a thickness that is substantially that of the two longitudinal sides.

12. The magnetic field sensor according to claim 6, further comprising:

an additional mass provided floatingly above the substrate in a middle of the two longitudinal sides.

13. The magnetic field sensor according to claim 6, wherein:

the deformation device includes a comb drive device connected to the two longitudinal sides.

14. The magnetic field sensor according to claim 1, wherein:

the conductor loop includes at least one non-deformable segment.

2. The magnetic field sensor according to claim wherein:

the magnetic field sensor is manufactured using a surface micromechanics technology.