Magnetic sensor, production method thereof, rotation detection device, and position detection device

• US 20070194787A1
• Filed: 02/21/2007
• Published: 08/23/2007
• Est. Priority Date: 02/23/2006
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: NEC Corporation
• Inventors: Nakase, Naoki, Takahashi, Yoshinori
• Granted Patent: US 7,642,773 B2
• Time in Patent Office: Days
• US Class Current: 324/252
• CPC Class Codes: G01R 33/0206 Three-component magnetometers
• CPC Class Codes: G01R 33/09 Magnetoresistive devices
• CPC Class Codes: G01R 33/096 anisotropic magnetoresistance sensors

Abstract

A one-chip type magnetic sensor is provided in which thin-film anisotropic magnetoresistance elements are formed on an IC substrate. Applied magnetic fields can be detected in the magnetic sensor in vertical and horizontal directions, and detection sensitivity can be adjusted with respect to direction. The influence on a magnetic-sensitive property can be suppressed when another magnetic field is applied from another direction. A semiconductor substrate, lead frame, and lead frame(s) are accommodated in a package in the magnetic sensor. Thin-film magnetoresistance elements are formed on the substrate, which includes an electric circuit having comparison and amplification functions. The lead frame is used to mount the semiconductor substrate thereon. The lead frames are connected to the semiconductor substrate, which is attached to a semiconductor attachment surface. The lead frame has a structure in which the semiconductor attachment surface is inclined with respect to a package surface by bending the lead frame.

Claims

1. A magnetic sensor comprising:

a magnetoresistance element unit including meandering thin-film magnetoresistance elements;

an IC circuit waveform processing unit including a comparator circuit and a feedback resistance, the magnetoresistance element unit and the IC circuit waveform processing unit being on a substrate;

a semiconductor substrate that is connected to both the magnetoresistance element unit and the IC circuit waveform processing unit; and

lead frames on which the semiconductor substrate is mounted, the semiconductor substrate and the lead frames being included in a package,

wherein;

the magnetoresistance element unit includes magnetoresistance elements that meander in different directions and forms a Wheatstone bridge, and

the semiconductor substrate is mounted onto a lead frame that slopes against a surface of the package.

2. The magnetic sensor according to claim 1, wherein the semiconductor substrate is mounted on a lead frame, the semiconductor substrate having the magnetoresistance element unit including a Wheatstone bridge.

3. The magnetic sensor according to claim 1, wherein a lead frame includes a stage portion to which the semiconductor substrate is attached and a frame portion that supports the stage portion, and the frame portion is bent to adjust an angle of a surface of the stage portion against a surface of the package.

4. The magnetic sensor according to claim 3, wherein a V-shape groove is cut on the frame portion.

5. The magnetic sensor according to claim 3, wherein the semiconductor substrate is attached to the stage portion that is at angle to an axis parallel to the frame portion.

6. The magnetic sensor according to claim 3, wherein the semiconductor substrate is attached to the stage portion that is at an angle to an axis orthogonal to the frame portion.

9. A rotation detection device comprising the magnetic sensor according to claim 1.

10. A position detection device comprising the magnetic sensor according claim 1.

11. A rotation detection device comprising the magnetic sensor according to claim 2.

12. A rotation detection device comprising the magnetic sensor according to claim 3.

13. A rotation detection device comprising the magnetic sensor according to claim 4.

14. A rotation detection device comprising the magnetic sensor according to claim 5.

15. A rotation detection device comprising the magnetic sensor according to claim 6.

16. A position detection device comprising the magnetic sensor according to claim 2.

17. A position detection device comprising the magnetic sensor according to claim 3.

18. A position detection device comprising the magnetic sensor according to claim 4.

19. A position detection device comprising the magnetic sensor according to claim 5.

20. A position detection device comprising the magnetic sensor according to claim 6.

7. A method for producing a magnetic sensor comprising a magnetoresistance element unit and an IC circuit waveform processing unit on a semiconductor substrate, the semiconductor substrate mounted on a lead frame that includes a frame portion and a stage portion, the method comprising the step of:

bending the frame portion;

adjusting an angle of the stage portion against a surface of a package; and

attaching the semiconductor substrate to a surface of the stage portion.

8. The magnetic sensor production method according to claim 7, wherein a V-shape groove is cut on the frame portion to adjust the angle of the stage portion.