Monolithic reference full bridge magnetic field sensor

A magnetic field sensor, monolithic technology, applied in the field of sensors, can solve the problems of low-cost mass production and difficulty in achieving consistent matching of magnetoresistive output

Active Publication Date: 2012-08-01
MULTIDIMENSION TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although MTJs or GMRs are compatible with semiconductor standard fabrication processes, high-sensitivity MTJ or GMR sensors have not been mass-produced at low cost
In particular, the yield of the sensor depends on the offset value of the reluctance output of the MTJ or GMR element, and the reluctance output of the MTJ or GMR element forming the bridge is difficult to achieve a consistent degree of matching

Method used

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  • Monolithic reference full bridge magnetic field sensor
  • Monolithic reference full bridge magnetic field sensor
  • Monolithic reference full bridge magnetic field sensor

Examples

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no. 3 example

[0090] In the third embodiment of the present invention, a single-chip reference full-bridge magnetic field sensor includes two reference arms and two sensing arms, and the two reference arms and the two sensing arms are connected at intervals to form a full bridge, each A bridge arm resistance is composed of one or more MTJ or GMR magneto-resistance elements; the MTJ or GMR magneto-resistance elements use the linear part of their output curves to induce magnetic fields; the magnetic field sensor also includes a wrapping reference arm The shielding layer of the magnetoresistive element, the shielding layer is a ferromagnetic material with high magnetic permeability; the pad of the magnetic field sensor can be connected to the packaging pin of the ASIC integrated circuit or the lead frame through a lead wire.

[0091] Preferably, the reference arm includes one or more magnetoresistive elements connected in series to adjust the resistance of the reference arm, and the sensing ...

no. 4 example

[0092] In the fourth embodiment of the present invention, a single-chip reference full-bridge magnetic field sensor includes two reference arms and two sensing arms, and the two reference arms and the two sensing arms are connected at intervals to form a full bridge Bridge, the reference arm and the sensing arm are composed of one or more MTJ or GMR magnetoresistive elements; the MTJ or GMR magnetoresistance elements use the linear part of their output curves to induce magnetic fields; the upper layer of the free layer of the reference arm element Or a layer of antiferromagnetic layer or permanent magnetic layer is deposited on the lower layer, and the reference arm is biased by using the exchange coupling of the antiferromagnetic layer or the exchange coupling and scattered field coupling of the permanent magnetic layer; the pad of the magnetic field sensor Can be wire-connected to the package pins of an ASIC integrated circuit or a lead frame.

[0093] Preferably, the mag...

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Abstract

The invention discloses a monolithic reference full bridge magnetic field sensor. The magnetic field sensor is a Wheatstone bridge formed by a magneto-resistor reference element and a sensing element. Both a sensing arm and a reference arm are magnetic tunnel junction resistance or giant magnetoresistance material. According to the invention, the sensitivity of the sensing element and the reference element are adjusted through one or one set of magnetic bias combination, exchange bias, magnetic shielding or shape anisotropy performance. In addition, bridge output offset and symmetry can be optimized through presetting and adjusting a resistance value ratio of the reference element to the sensing element. Through using the technology, the magnetic field sensor presents excellent temperature stability, low offset voltage and excellent voltage symmetry.

Description

technical field [0001] The invention relates to a sensor for magnetic field detection, especially a single-chip reference full-bridge magnetic field sensor. Background technique [0002] Magnetic field sensors are widely used in modern systems to measure and detect physical quantities, including but not limited to the measurement of parameters such as magnetic field strength, current, position, power, and direction. Although there are many types of sensors for measuring magnetic fields and other physical parameters, these technologies have limitations, such as large size, low sensitivity, narrow dynamic range, high manufacturing cost, poor stability, and other disadvantages. Accordingly, there is a continuing need for improvements in magnetic sensors, especially sensors that are easily integrated with semiconductor devices and integrated circuits, and methods of fabrication thereof. [0003] Magnetic tunnel junction sensors have the advantages of high sensitivity, small siz...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01R33/09
CPCG01R33/098H01L43/02H10N50/80
Inventor 詹姆斯·G·迪克金英西沈卫锋薛松生王建国雷啸锋
Owner MULTIDIMENSION TECH CO LTD
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