JP2022138864A - magnetic sensor - Google Patents

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JP2022138864A
JP2022138864A JP2021038977A JP2021038977A JP2022138864A JP 2022138864 A JP2022138864 A JP 2022138864A JP 2021038977 A JP2021038977 A JP 2021038977A JP 2021038977 A JP2021038977 A JP 2021038977A JP 2022138864 A JP2022138864 A JP 2022138864A
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magnetic
magnetoresistive
magnetoresistive element
ferromagnetic
magnetic sensor
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康二 黒木
Koji Kuroki
進 原谷
Susumu Haratani
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TDK Corp
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
    • G01R33/06—Measuring direction or magnitude of magnetic fields or magnetic flux using galvano-magnetic devices
    • G01R33/09—Magnetoresistive devices
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N50/00—Galvanomagnetic devices
    • H10N50/10—Magnetoresistive devices
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N50/00—Galvanomagnetic devices
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  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Magnetic Variables (AREA)
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Abstract

To provide a magnetic sensor equipped with a magnetoresistive strip and a ferromagnetic film, in which a decrease in the magnetic bias applied to a magnetoresistive element is suppressed.SOLUTION: A magnetic sensor 1 comprises: a magnetoresistive strip S extending in a y direction; and ferromagnetic films M1, M2 arrayed in an x direction via a magnetic gap G extending in the y direction. The magnetoresistive strip S is arranged at a position that overlaps the magnetic gap G as seen from a z direction. A width of the magnetic gap G in the x direction is wider for a portion overlapping a hard magnetic substance H than for a portion overlapping a magnetoresistive element R. Thus, as the width of the magnetic gap G is expanded in the portion overlapping the hard magnetic substance H, the magnetic field generated from the hard magnetic substance H is less absorbable by the ferromagnetic films M1, M2. Consequently, as a decrease in the magnetic bias applied to the magnetoresistive element R is suppressed, it is possible to effectively reduce irregular noise superimposed on a detection signal.SELECTED DRAWING: Figure 1

Description

本発明は磁気センサに関し、特に、磁気抵抗素子に磁気バイアスを印加する硬磁性体を備えた磁気センサに関する。 The present invention relates to a magnetic sensor, and more particularly to a magnetic sensor having a hard magnetic material that applies a magnetic bias to a magnetoresistive element.

磁気センサとしては、特許文献１に記載されているように、磁気抵抗素子の抵抗値変化に基づいて磁界の向き及び強さを検出するタイプの磁気センサが知られている。特許文献１に記載された磁気センサは、磁気抵抗素子を分断する複数の硬磁性体（磁石）を配置することによって、磁気抵抗素子に磁気バイアスを印加している。磁気抵抗素子に磁気バイアスを印加すれば、理想的には磁気抵抗素子が単磁区化されるため、検出信号に重畳する不規則ノイズを低減することが可能となる。 2. Description of the Related Art As a magnetic sensor, a type of magnetic sensor that detects the direction and strength of a magnetic field based on changes in the resistance value of a magnetoresistive element is known, as described in Patent Document 1. The magnetic sensor described in Patent Document 1 applies a magnetic bias to the magnetoresistive element by arranging a plurality of hard magnetic bodies (magnets) that divide the magnetoresistive element. If a magnetic bias is applied to the magnetoresistive element, the magnetoresistive element is ideally made into a single magnetic domain, so that random noise superimposed on the detection signal can be reduced.

特許第５０６６５７９号公報Japanese Patent No. 5066579

しかしながら、磁気抵抗素子に磁界を集中させるための強磁性膜を用いた場合、硬磁性体から生じる磁界が硬磁性体に吸収されてしまい、磁気抵抗素子に印加される磁気バイアスが低下するという問題があった。 However, when a ferromagnetic film is used to concentrate the magnetic field on the magnetoresistive element, the magnetic field generated by the hard magnetic material is absorbed by the hard magnetic material, resulting in a decrease in the magnetic bias applied to the magnetoresistive element. was there.

したがって、本発明は、磁気抵抗ストリップと強磁性膜を備えた磁気センサにおいて、磁気抵抗素子に印加される磁気バイアスの低下を抑制することを目的とする。 SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to suppress a decrease in the magnetic bias applied to a magnetoresistive element in a magnetic sensor having a magnetoresistive strip and a ferromagnetic film.

本発明による磁気センサは、磁気バイアスを与える複数の硬磁性体を介して第１の方向に配列された複数の磁気抵抗素子からなる磁気抵抗ストリップと、第１の方向に延在する磁気ギャップを介して第１の方向と交差する第２の方向に配列された第１及び第２の強磁性膜とを備え、磁気抵抗ストリップは、第１及び第２の方向で定義される平面と交差する第３の方向から見て磁気ギャップと重なる位置に配置され、磁気ギャップの第２の方向における幅は、磁気抵抗素子と重なる部分よりも硬磁性体と重なる部分の方が広いことを特徴とする。 A magnetic sensor according to the present invention includes a magnetoresistive strip composed of a plurality of magnetoresistive elements arranged in a first direction via a plurality of hard magnetic bodies that provide a magnetic bias, and a magnetic gap extending in the first direction. first and second ferromagnetic films arranged in a second direction intersecting the first direction through the magnetoresistive strip intersecting the plane defined by the first and second directions It is arranged at a position overlapping with the magnetic gap when viewed from the third direction, and the width in the second direction of the magnetic gap is characterized in that the portion overlapping with the hard magnetic material is wider than the portion overlapping with the magnetoresistive element. .

本発明によれば、硬磁性体と重なる部分において磁気ギャップの幅が拡大されていることから、硬磁性体から生じる磁界が強磁性膜に吸収されにくくなる。これにより、磁気抵抗素子に印加される磁気バイアスの低下が抑制されることから、検出信号に重畳する不規則ノイズを効果的に低減することが可能となる。 According to the present invention, since the width of the magnetic gap is increased in the portion overlapping with the hard magnetic material, the magnetic field generated by the hard magnetic material is less likely to be absorbed by the ferromagnetic film. As a result, the decrease in the magnetic bias applied to the magnetoresistive element is suppressed, so that random noise superimposed on the detection signal can be effectively reduced.

本発明において、複数の磁気抵抗素子は第１の強磁性膜と重なりを有していても構わない。これによれば、第１の強磁性膜によって集磁された磁界を効率よく磁気抵抗素子に印加することが可能となる。この場合、第１の強磁性膜のうち複数の磁気抵抗素子と重なる部分は、第３の方向から見て角部を有していても構わない。これによれば、角部に集中する磁界を効率よく磁気抵抗素子に印加することが可能となる。 In the present invention, the plurality of magnetoresistive elements may overlap the first ferromagnetic film. According to this, it is possible to efficiently apply the magnetic field collected by the first ferromagnetic film to the magnetoresistive element. In this case, the portions of the first ferromagnetic film overlapping the plurality of magnetoresistive elements may have corners when viewed from the third direction. According to this, it is possible to efficiently apply a magnetic field concentrated on the corner to the magnetoresistive element.

本発明による磁気センサは、第１の強磁性膜と重なりを有し、第３の方向を長手方向とする外部磁性体をさらに備えていても構わない。これによれば、第３の方向の磁界を外部磁性体によって集磁し、これを磁気抵抗素子に印加することが可能となる。 The magnetic sensor according to the present invention may further include an external magnetic body overlapping the first ferromagnetic film and having a longitudinal direction in the third direction. According to this, the magnetic field in the third direction can be collected by the external magnetic body and applied to the magnetoresistive element.

本発明において、複数の磁気抵抗素子は第２の強磁性膜と重なりを有していても構わない。これによれば、磁気ギャップを通過する磁界をより効率よく磁気抵抗素子に印加することが可能となる。 In the present invention, the plurality of magnetoresistive elements may overlap the second ferromagnetic film. According to this, it becomes possible to more efficiently apply the magnetic field passing through the magnetic gap to the magnetoresistive element.

本発明において、複数の硬磁性体は第１及び第２の強磁性膜と重ならなくても構わない。これによれば、硬磁性体から生じる磁界が強磁性膜により吸収されにくくなる。 In the present invention, the plurality of hard magnetic bodies need not overlap the first and second ferromagnetic films. According to this, the magnetic field generated from the hard magnetic material is less likely to be absorbed by the ferromagnetic film.

このように、本発明によれば、磁気抵抗ストリップと強磁性膜を備えた磁気センサにおいて、磁気抵抗素子に印加される磁気バイアスの低下を抑制することが可能となる。 As described above, according to the present invention, it is possible to suppress a decrease in the magnetic bias applied to the magnetoresistive element in a magnetic sensor including a magnetoresistive strip and a ferromagnetic film.

図１は、本発明の第１の実施形態による磁気センサ１の構造を説明するための略平面図である。FIG. 1 is a schematic plan view for explaining the structure of a magnetic sensor 1 according to a first embodiment of the invention. 図２（ａ）は図１に示すＡ－Ａ線に沿った略断面図であり、図２（ｂ）は図１に示すＢ－Ｂ線に沿った略断面図である。2(a) is a schematic cross-sectional view taken along line AA shown in FIG. 1, and FIG. 2(b) is a schematic cross-sectional view taken along line BB shown in FIG. 図３は、磁気センサ１の構造をより詳細に説明するための部分平面図である。FIG. 3 is a partial plan view for explaining the structure of the magnetic sensor 1 in more detail. 図４は、磁気センサ１の変形例の構造をより詳細に説明するための部分平面図である。FIG. 4 is a partial plan view for explaining the structure of the modified example of the magnetic sensor 1 in more detail. 図５は、本発明の第２の実施形態による磁気センサ２の構造を説明するための略平面図である。FIG. 5 is a schematic plan view for explaining the structure of the magnetic sensor 2 according to the second embodiment of the invention. 図６は、図５に示すＡ－Ａ線に沿った略断面図である。FIG. 6 is a schematic cross-sectional view along line AA shown in FIG. 図７は、磁気センサ２の主要部の第１の例を示す部分平面図である。FIG. 7 is a partial plan view showing a first example of the main part of the magnetic sensor 2. FIG. 図８は、磁気センサ２の主要部の第２の例を示す部分平面図である。FIG. 8 is a partial plan view showing a second example of the main part of the magnetic sensor 2. FIG. 図９は、磁気センサ２の主要部の第３の例を示す部分平面図である。FIG. 9 is a partial plan view showing a third example of the main part of the magnetic sensor 2. As shown in FIG. 図１０は、磁気センサ２の主要部の第４の例を示す部分平面図である。FIG. 10 is a partial plan view showing a fourth example of the main part of the magnetic sensor 2. As shown in FIG. 図１１は、磁気センサ２の主要部の第５の例を示す部分平面図である。FIG. 11 is a partial plan view showing a fifth example of the main part of the magnetic sensor 2. FIG.

以下、添付図面を参照しながら、本発明の好ましい実施形態について詳細に説明する。 Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

＜第１の実施形態＞
図１は、本発明の第１の実施形態による磁気センサ１の構造を説明するための略平面図である。また、図２（ａ）は図１に示すＡ－Ａ線に沿った略断面図であり、図２（ｂ）は図１に示すＢ－Ｂ線に沿った略断面図である。 <First embodiment>
FIG. 1 is a schematic plan view for explaining the structure of a magnetic sensor 1 according to a first embodiment of the invention. 2(a) is a schematic cross-sectional view taken along line AA shown in FIG. 1, and FIG. 2(b) is a schematic cross-sectional view taken along line BB shown in FIG.

図１及び図２に示すように、第１の実施形態による磁気センサ１は、ｙ方向に延在する磁気抵抗ストリップＳと、ｘ方向に配列された２つの強磁性膜Ｍ１，Ｍ２を備えている。磁気抵抗ストリップＳは、絶縁膜１２を介してセンサ基板１１上に形成されており、複数の硬磁性体（磁石）Ｈを介してｙ方向に配列された複数の磁気抵抗素子Ｒからなる。磁気抵抗素子Ｒの材料としては、磁界の向き及び強度によって抵抗値が変化するものであれば特に限定されない。磁気抵抗素子Ｒは、複数の硬磁性体Ｈによってｙ方向に分断されており、硬磁性体Ｈによって印加される磁気バイアスによって実質的に単磁区化される。これにより、磁区の乱れに起因する不規則ノイズが低減される。磁気抵抗素子Ｒを確実に単磁区化するためには、個々の磁気抵抗素子Ｒのｙ方向における長さを数μｍ程度とすることが好ましい。 As shown in FIGS. 1 and 2, the magnetic sensor 1 according to the first embodiment comprises a magnetoresistive strip S extending in the y direction and two ferromagnetic films M1 and M2 arranged in the x direction. there is The magnetoresistive strip S is formed on the sensor substrate 11 with an insulating film 12 interposed therebetween, and consists of a plurality of magnetoresistive elements R arranged in the y direction with a plurality of hard magnetic bodies (magnets) H interposed therebetween. The material of the magnetoresistive element R is not particularly limited as long as the resistance value changes depending on the direction and strength of the magnetic field. The magnetoresistive element R is divided in the y-direction by a plurality of hard magnetic bodies H, and is substantially single-domained by the magnetic bias applied by the hard magnetic bodies H. FIG. This reduces random noise caused by disturbance of magnetic domains. In order to ensure that the magnetoresistive element R has a single magnetic domain, it is preferable to set the length of each magnetoresistive element R in the y direction to about several μm.

磁気抵抗ストリップＳは、Ａｌ２Ｏ３などからなる絶縁膜１３で覆われる。パーマロイなどからなる強磁性膜Ｍ１，Ｍ２は絶縁膜１３の表面に形成され、ｙ方向に延在する磁気ギャップＧを介してｘ方向に配列されている。そして、磁気抵抗ストリップＳは、ｚ方向から見た平面視で磁気ギャップＧと重なる位置に配置されている。ここで、部分拡大図である図３に示すように、磁気抵抗ストリップＳのｘ方向における幅Ｗｓがほぼ一定であるのに対し、磁気ギャップＧのｘ方向における幅は、磁気抵抗素子Ｒと重なる部分においてはＷ１であり、硬磁性体Ｈと重なる部分においてはＷ２（＞Ｗ１）である。つまり、磁気ギャップＧのｘ方向における幅は、磁気抵抗素子Ｒと重なる部分よりも硬磁性体Ｈと重なる部分の方が広い。また、本実施形態においては、ｚ方向から見て、強磁性膜Ｍ１，Ｍ２が絶縁膜１３を介して磁気抵抗素子Ｒと部分的な重なりを有しているのに対し、強磁性膜Ｍ１，Ｍ２と硬磁性体Ｈは重なりを有していない。 The magnetoresistive strip S is covered with an insulating film 13 made of Al 2 O 3 or the like. Ferromagnetic films M1 and M2 made of permalloy or the like are formed on the surface of the insulating film 13 and arranged in the x direction via a magnetic gap G extending in the y direction. The magnetoresistive strip S is arranged at a position overlapping the magnetic gap G in plan view in the z direction. Here, as shown in FIG. 3, which is a partially enlarged view, the width Ws of the magnetoresistive strip S in the x direction is substantially constant, whereas the width of the magnetic gap G in the x direction overlaps the magnetoresistive element R. It is W1 at the portion where it overlaps with the hard magnetic material H, and W2 (>W1) at the portion where it overlaps with the hard magnetic material H. That is, the width of the magnetic gap G in the x direction is wider at the portion overlapping the hard magnetic material H than at the portion overlapping the magnetoresistive element R. In this embodiment, the ferromagnetic films M1 and M2 partially overlap the magnetoresistive element R with the insulating film 13 interposed therebetween when viewed from the z-direction. M2 and hard magnetic body H have no overlap.

図３に示すように、強磁性膜Ｍ１，Ｍ２は、磁気抵抗素子Ｒと重なる部分においてｘ方向に突出する形状を有しており、突出部のｙ方向における幅はＬｍである。幅Ｌｍは、磁気抵抗素子Ｒのｙ方向における長さＬｒよりも短く、これにより、ｚ方向から見た強磁性膜Ｍ１，Ｍ２の角部Ｃは、磁気抵抗素子Ｒと重なる。これにより、強磁性膜Ｍ１から強磁性膜Ｍ２に向かう検出磁界、或いは、強磁性膜Ｍ２から強磁性膜Ｍ１に向かう検出磁界は、ほぼ直角な角部Ｃに集中し、角部Ｃから漏洩するｘ方向の検出磁界が磁気抵抗素子Ｒに印加される。 As shown in FIG. 3, the ferromagnetic films M1 and M2 have a shape that protrudes in the x direction at the portion overlapping the magnetoresistive element R, and the width of the protrusion in the y direction is Lm. The width Lm is shorter than the length Lr of the magnetoresistive element R in the y direction, so that the corners C of the ferromagnetic films M1 and M2 overlap the magnetoresistive element R when viewed in the z direction. As a result, the detection magnetic field directed from the ferromagnetic film M1 to the ferromagnetic film M2 or the detection magnetic field directed from the ferromagnetic film M2 to the ferromagnetic film M1 concentrates on the substantially right-angled corner C and leaks from the corner C. A detection magnetic field in the x-direction is applied to the magnetoresistive element R.

これに対し、硬磁性体Ｈは、ｚ方向から見て強磁性膜Ｍ１，Ｍ２と重なりを有していないことから、硬磁性体Ｈから生じる磁界は、一部が強磁性膜Ｍ１，Ｍ２に吸収されるものの、大部分が磁気抵抗素子Ｒに印加される。これにより、磁気抵抗素子Ｒに十分な磁気バイアスを印加することが可能となり、検出信号に重畳する不規則ノイズを効果的に低減することが可能となる。 On the other hand, since the hard magnetic material H does not overlap the ferromagnetic films M1 and M2 when viewed from the z-direction, the magnetic field generated from the hard magnetic material H is partially applied to the ferromagnetic films M1 and M2. Most of it is applied to the magnetoresistive element R, although it is absorbed. This makes it possible to apply a sufficient magnetic bias to the magnetoresistive element R and effectively reduce random noise superimposed on the detection signal.

但し、本発明において、磁気抵抗ストリップＳのｘ方向における幅Ｗｓが一定である点は必須でなく、変形例である図４に示すように、磁気抵抗素子Ｒのｘ方向における幅Ｗｒよりも、硬磁性体Ｈのｘ方向における幅Ｗｈの方が広くても構わない。この場合、磁気ギャップＧの幅Ｗ１を磁気抵抗素子Ｒの幅Ｗｒよりも狭くするとともに、磁気ギャップＧの幅Ｗ２を硬磁性体Ｈの幅Ｗｈよりも広くすればよい。 However, in the present invention, it is not essential that the width Ws of the magnetoresistive strip S in the x direction be constant. The width Wh of the hard magnetic body H in the x direction may be wider. In this case, the width W1 of the magnetic gap G should be made narrower than the width Wr of the magnetoresistive element R, and the width W2 of the magnetic gap G should be made wider than the width Wh of the hard magnetic material H.

図１に示すように、磁気抵抗ストリップＳのｙ方向における一端は端子電極Ｅ１に接続され、他端は端子電極Ｅ２に接続される。端子電極Ｅ１，Ｅ２は図示しない検出回路に接続され、端子電極Ｅ１，Ｅ２間の抵抗値に基づいて、検出磁界を測定することが可能となる。 As shown in FIG. 1, one end of the magnetoresistive strip S in the y-direction is connected to the terminal electrode E1, and the other end is connected to the terminal electrode E2. The terminal electrodes E1 and E2 are connected to a detection circuit (not shown), and the detected magnetic field can be measured based on the resistance value between the terminal electrodes E1 and E2.

以上説明したように、本実施形態による磁気センサ１は、強磁性膜Ｍ１，Ｍ２によって構成される磁気ギャップＧのｘ方向における幅が硬磁性体Ｈと重なる位置において局所的に拡大されていることから、検出磁界を磁気抵抗素子Ｒに効果的に印加することができるとともに、硬磁性体Ｈから生じる磁界が強磁性膜Ｍ１，Ｍ２に吸収されることによる磁気バイアスの低下を抑えることが可能となる。 As described above, in the magnetic sensor 1 according to the present embodiment, the width in the x direction of the magnetic gap G formed by the ferromagnetic films M1 and M2 is locally enlarged at the position overlapping the hard magnetic material H. Therefore, it is possible to effectively apply the detection magnetic field to the magnetoresistive element R, and to suppress the decrease in the magnetic bias due to the magnetic field generated from the hard magnetic material H being absorbed by the ferromagnetic films M1 and M2. Become.

＜第２の実施形態＞
図５は、本発明の第２の実施形態による磁気センサ２の構造を説明するための略平面図である。また、図６は、図５に示すＡ－Ａ線に沿った略断面図である。 <Second embodiment>
FIG. 5 is a schematic plan view for explaining the structure of the magnetic sensor 2 according to the second embodiment of the invention. 6 is a schematic cross-sectional view along line AA shown in FIG.

図５及び図６に示すように、第２の実施形態による磁気センサ２は、センサ基板２１上にこの順に積層された絶縁膜２２～２４と、絶縁膜２２の表面に設けられた４つの磁気抵抗ストリップＳ１～Ｓ４と、絶縁膜２４の表面に設けられた３つの強磁性膜Ｍ１１～Ｍ１３とを備える。 As shown in FIGS. 5 and 6, the magnetic sensor 2 according to the second embodiment includes insulating films 22 to 24 laminated in this order on a sensor substrate 21, and four magnetic fields provided on the surface of the insulating film 22. It comprises resistor strips S1-S4 and three ferromagnetic films M11-M13 provided on the surface of the insulating film .

磁気抵抗ストリップＳ１～Ｓ４は、上述した磁気抵抗ストリップＳと同様、複数の硬磁性体Ｈを介してｙ方向に配列された複数の磁気抵抗素子Ｒによって構成される。また、強磁性膜Ｍ１１，Ｍ１２は、ｙ方向に延在する磁気ギャップＧ１，Ｇ３を介してｘ方向に配列され、強磁性膜Ｍ１１，Ｍ１３は、ｙ方向に延在する磁気ギャップＧ２，Ｇ４を介してｘ方向に配列されている。そして、ｚ方向から見て磁気ギャップＧ１～Ｇ４と重なる位置にそれぞれ磁気抵抗ストリップＳ１～Ｓ４が配置される。磁気ギャップＧ１～Ｇ４と磁気抵抗ストリップＳ１～Ｓ４の重なりについては第１の実施形態と同じであり、磁気抵抗素子Ｒについては対応する強磁性膜Ｍ１１～Ｍ１３と部分的に重なり、硬磁性体Ｈについては強磁性膜Ｍ１１～Ｍ１３と重なりを有しない。 The magnetoresistive strips S1 to S4 are composed of a plurality of magnetoresistive elements R arranged in the y direction with a plurality of hard magnetic bodies H interposed therebetween, like the magnetoresistive strip S described above. The ferromagnetic films M11 and M12 are arranged in the x direction through magnetic gaps G1 and G3 extending in the y direction, and the ferromagnetic films M11 and M13 are arranged in magnetic gaps G2 and G4 extending in the y direction. are arranged in the x-direction through the Magnetoresistive strips S1 to S4 are arranged at positions overlapping the magnetic gaps G1 to G4 when viewed in the z-direction. The overlapping of the magnetic gaps G1 to G4 and the magnetoresistive strips S1 to S4 is the same as in the first embodiment. do not overlap with the ferromagnetic films M11 to M13.

さらに、本実施形態による磁気センサ２は、センサ基板２１の上面側に設けられた外部磁性体２５と、センサ基板２１の裏面及び側面を覆う外部磁性体２６を備える。外部磁性体２５，２６は、フェライトなどの軟磁性材料からなり、ｚ方向の検出磁界を効率よく集磁する役割を果たす。外部磁性体２５は、絶縁膜２４を介して強磁性膜Ｍ１１を覆う位置に設けられ、これにより、外部磁性体２５によって集磁されたｚ方向の検出磁界は、強磁性膜Ｍ１１に取り込まれ、磁気ギャップＧ１～Ｇ４を介して強磁性膜Ｍ１２，Ｍ１３に分配される。そして、強磁性膜Ｍ１１から強磁性膜Ｍ１２に向かう検出磁界は、磁気抵抗ストリップＳ１，Ｓ３に対して－ｘ方向に印加され、強磁性膜Ｍ１１から強磁性膜Ｍ１３に向かう検出磁界は、磁気抵抗ストリップＳ２，Ｓ４に対して＋ｘ方向に印加される。つまり、磁気抵抗ストリップＳ１，Ｓ３と磁気抵抗ストリップＳ２，Ｓ４には、検出磁界が互いに逆方向に印加されることになる。したがって、磁気抵抗ストリップＳ１～Ｓ４をブリッジ接続すれば、検出磁界をより高感度に検出することが可能となる。 Further, the magnetic sensor 2 according to this embodiment includes an external magnetic body 25 provided on the upper surface side of the sensor substrate 21 and an external magnetic body 26 covering the rear surface and side surfaces of the sensor substrate 21 . The external magnetic bodies 25 and 26 are made of a soft magnetic material such as ferrite, and serve to efficiently collect the detection magnetic field in the z direction. The external magnetic body 25 is provided at a position covering the ferromagnetic film M11 with the insulating film 24 interposed therebetween. It is distributed to the ferromagnetic films M12 and M13 via the magnetic gaps G1 to G4. A detection magnetic field directed from the ferromagnetic film M11 to the ferromagnetic film M12 is applied in the -x direction to the magnetoresistive strips S1 and S3, and a detection magnetic field directed from the ferromagnetic film M11 to the ferromagnetic film M13 is applied to the magnetoresistive strips S1 and S3. It is applied in the +x direction to strips S2 and S4. That is, the detection magnetic fields are applied in opposite directions to the magnetoresistive strips S1, S3 and the magnetoresistive strips S2, S4. Therefore, if the magnetoresistive strips S1 to S4 are bridge-connected, the detection magnetic field can be detected with higher sensitivity.

ここで、ｚ方向を長手方向とする外部磁性体２５のｚ方向における先端２５Ａを検出ヘッドとして用いる場合、検出磁界は、強磁性膜Ｍ１１から強磁性膜Ｍ１２，Ｍ１３側へ流れることになる。この場合、強磁性膜Ｍ１１から強磁性膜Ｍ１２，Ｍ１３側へ流れる検出磁界が磁気抵抗素子Ｒに効果的に印加されるよう、強磁性膜Ｍ１１～Ｍ１３の形状を工夫しても構わない。 Here, when the tip 25A in the z direction of the external magnetic body 25 whose longitudinal direction is the z direction is used as a detection head, the detection magnetic field flows from the ferromagnetic film M11 to the ferromagnetic films M12 and M13. In this case, the shapes of the ferromagnetic films M11 to M13 may be devised so that the detection magnetic field flowing from the ferromagnetic film M11 toward the ferromagnetic films M12 and M13 is effectively applied to the magnetoresistive element R.

例えば、図７に示す第１の例のように、強磁性膜Ｍ１１の突出幅Ｌｍ１を強磁性膜Ｍ１２（Ｍ１３）の突出幅Ｌｍ２よりも小さくしても構わない。これによれば、磁界が集中する強磁性膜Ｍ１１の角部Ｃが磁気抵抗素子Ｒのｙ方向におけるより中央に位置するため、検出感度が高められる。 For example, as in the first example shown in FIG. 7, the protrusion width Lm1 of the ferromagnetic film M11 may be smaller than the protrusion width Lm2 of the ferromagnetic film M12 (M13). According to this, the corner C of the ferromagnetic film M11 where the magnetic field concentrates is located in the center of the magnetoresistive element R in the y direction, so that the detection sensitivity is enhanced.

また、図８に示す第２の例のように、ｚ方向から見て強磁性膜Ｍ１２（Ｍ１３）が磁気抵抗素子Ｒと重ならない構造であっても構わない。この場合であっても、磁界が集中する強磁性膜Ｍ１１の角部Ｃが磁気抵抗素子Ｒと重なるため、検出磁界を正しく検出することが可能である。 Further, as in the second example shown in FIG. 8, the structure may be such that the ferromagnetic film M12 (M13) does not overlap the magnetoresistive element R when viewed from the z direction. Even in this case, since the corner C of the ferromagnetic film M11 where the magnetic field concentrates overlaps with the magnetoresistive element R, it is possible to correctly detect the detected magnetic field.

また、図９に示す第３の例のように強磁性膜Ｍ１１のエッジを台形に切り欠く、或いは、図１０に示す第４の例のように強磁性膜Ｍ１１のエッジを半円形に切り欠くことによって、磁気抵抗素子Ｒと重なる突出部を形成しても構わない。このように、強磁性膜Ｍ１１の突出部の形状については特に限定されない。 Also, the edge of the ferromagnetic film M11 is notched in a trapezoidal shape as in the third example shown in FIG. 9, or the edge of the ferromagnetic film M11 is notched in a semicircular shape as in the fourth example shown in FIG. Thus, a projecting portion that overlaps with the magnetoresistive element R may be formed. Thus, the shape of the projecting portion of the ferromagnetic film M11 is not particularly limited.

さらに、図１１に示す第５の例のように、ｚ方向から見て強磁性膜Ｍ１１が磁気抵抗素子Ｒと重ならない構造であっても構わない。この場合であっても、磁気ギャップＧ１～Ｇ４のｘ方向における幅を、磁気抵抗素子Ｒと重なる部分においてはＷ１とし、硬磁性体Ｈと重なる部分においてはＷ２（＞Ｗ１）とすることにより、硬磁性体Ｈから生じる磁界が強磁性膜Ｍ１１～Ｍ１３に吸収されることによる磁気バイアスの低下を抑えることが可能である。 Furthermore, as in the fifth example shown in FIG. 11, the structure may be such that the ferromagnetic film M11 does not overlap the magnetoresistive element R when viewed from the z direction. Even in this case, the width in the x direction of the magnetic gaps G1 to G4 is set to W1 in the portion overlapping with the magnetoresistive element R and W2 (>W1) in the portion overlapping with the hard magnetic material H, It is possible to suppress the decrease in the magnetic bias due to the magnetic field generated by the hard magnetic material H being absorbed by the ferromagnetic films M11 to M13.

以上、本発明の好ましい実施形態について説明したが、本発明は、上記の実施形態に限定されることなく、本発明の主旨を逸脱しない範囲で種々の変更が可能であり、それらも本発明の範囲内に包含されるものであることはいうまでもない。 Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. Needless to say, it is included within the scope.

１，２ 磁気センサ
１１，２１ センサ基板
１２，１３，２２～２４ 絶縁膜
２５，２６ 外部磁性体
２５Ａ 外部磁性体の先端
Ｃ 角部
Ｅ１，Ｅ２ 端子電極
Ｇ，Ｇ１～Ｇ４ 磁気ギャップ
Ｈ 硬磁性体
Ｍ１，Ｍ２，Ｍ１１～Ｍ１３ 強磁性膜
Ｒ 磁気抵抗素子
Ｓ，Ｓ１～Ｓ４ 磁気抵抗ストリップ 1, 2 magnetic sensors 11, 21 sensor substrates 12, 13, 22 to 24 insulating films 25, 26 external magnetic body 25A tip C of external magnetic body corners E1, E2 terminal electrodes G, G1 to G4 magnetic gap H hard magnetic body M1, M2, M11 to M13 ferromagnetic film R magnetoresistive element S, S1 to S4 magnetoresistive strip

Claims (6)

磁気バイアスを与える複数の硬磁性体を介して第１の方向に配列された複数の磁気抵抗素子からなる磁気抵抗ストリップと、
前記第１の方向に延在する磁気ギャップを介して、前記第１の方向と交差する第２の方向に配列された第１及び第２の強磁性膜と、を備え、
前記磁気抵抗ストリップは、前記第１及び第２の方向で定義される平面と交差する第３の方向から見て、前記磁気ギャップと重なる位置に配置され、
前記磁気ギャップの前記第２の方向における幅は、前記磁気抵抗素子と重なる部分よりも前記硬磁性体と重なる部分の方が広いことを特徴とする磁気センサ。 a magnetoresistive strip comprising a plurality of magnetoresistive elements arranged in a first direction via a plurality of hard magnetic bodies that provide a magnetic bias;
first and second ferromagnetic films arranged in a second direction intersecting the first direction via a magnetic gap extending in the first direction;
the magnetoresistive strip is positioned to overlap the magnetic gap when viewed in a third direction that intersects the plane defined by the first and second directions;
The magnetic sensor according to claim 1, wherein the width of the magnetic gap in the second direction is wider at a portion overlapping with the hard magnetic body than at a portion overlapping with the magnetoresistive element. 前記複数の磁気抵抗素子は、前記第１の強磁性膜と重なりを有することを特徴とする請求項１に記載の磁気センサ。 2. The magnetic sensor according to claim 1, wherein said plurality of magnetoresistive elements overlap said first ferromagnetic film. 前記第１の強磁性膜のうち前記複数の磁気抵抗素子と重なる部分は、前記第３の方向から見て角部を有することを特徴とする請求項２に記載の磁気センサ。 3. The magnetic sensor according to claim 2, wherein portions of said first ferromagnetic film overlapping with said plurality of magnetoresistive elements have corners when viewed from said third direction. 前記第１の強磁性膜と重なりを有し、前記第３の方向を長手方向とする外部磁性体をさらに備えることを特徴とする請求項２又は３に記載の磁気センサ。 4. The magnetic sensor according to claim 2, further comprising an external magnetic body having an overlap with the first ferromagnetic film and having a longitudinal direction in the third direction. 前記複数の磁気抵抗素子は、前記第２の強磁性膜と重なりを有することを特徴とする請求項２乃至４のいずれか一項に記載の磁気センサ。 5. The magnetic sensor according to claim 2, wherein the plurality of magnetoresistive elements overlap the second ferromagnetic film. 前記複数の硬磁性体は、前記第１及び第２の強磁性膜と重ならないことを特徴とする請求項１乃至５のいずれか一項に記載の磁気センサ。 6. The magnetic sensor according to claim 1, wherein the plurality of hard magnetic bodies do not overlap the first and second ferromagnetic films.
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JPS6391818A (en) * 1986-10-03 1988-04-22 Sharp Corp Yoke type magneto-resistance thin film head
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US5737156A (en) * 1993-11-08 1998-04-07 Seagate Technology, Inc. Barberpole MR sensor having interleaved permanent magnet and magnetoresistive segments
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