WO2009087937A1 - Magnetic sensor and magnetic encoder - Google Patents

Magnetic sensor and magnetic encoder Download PDF

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Publication number
WO2009087937A1
WO2009087937A1 PCT/JP2008/073870 JP2008073870W WO2009087937A1 WO 2009087937 A1 WO2009087937 A1 WO 2009087937A1 JP 2008073870 W JP2008073870 W JP 2008073870W WO 2009087937 A1 WO2009087937 A1 WO 2009087937A1
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Prior art keywords
magnetoresistive
terminal
magnetoresistive effect
phase
effect element
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PCT/JP2008/073870
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French (fr)
Japanese (ja)
Inventor
Hideto Ando
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Alps Electric Co., Ltd.
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Publication date
Application filed by Alps Electric Co., Ltd. filed Critical Alps Electric Co., Ltd.
Priority to JP2009548894A priority Critical patent/JP4914502B2/en
Publication of WO2009087937A1 publication Critical patent/WO2009087937A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/244—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing characteristics of pulses or pulse trains; generating pulses or pulse trains
    • G01D5/245—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing characteristics of pulses or pulse trains; generating pulses or pulse trains using a variable number of pulses in a train
    • G01D5/2451—Incremental encoders
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y25/00—Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
    • G01D5/142—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices
    • G01D5/145—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices influenced by the relative movement between the Hall device and magnetic fields
    • 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
    • G01R33/091—Constructional adaptation of the sensor to specific applications
    • 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
    • G01R33/093—Magnetoresistive devices using multilayer structures, e.g. giant magnetoresistance sensors
    • 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

Definitions

  • the present invention particularly relates to a magnetic sensor and a magnetic encoder capable of improving the arrangement of terminals electrically connected to a magnetoresistive effect element and realizing miniaturization.
  • a magnetoresistive element (GMR element) using a giant magnetoresistive effect (GMR effect) can be used for a magnetic encoder.
  • FIG. 10 is a plan view of a magnetic sensor 90 constituting a conventional magnetic encoder. Eight magnetoresistive effect elements 91 to 98 are provided, and each of the four magnetoresistive effect elements is combined to constitute an A-phase bridge circuit and a B-phase bridge circuit.
  • one input terminal 99 and one ground terminal 100 are provided.
  • the input terminal 99 and the ground terminal 100 are common terminals for the A-phase bridge circuit and the B-phase bridge circuit.
  • the input terminal 99, the ground terminal 100, and the output terminals 101 to 104 are in the vertical direction (Y direction) orthogonal to the relative movement direction (X direction) of the magnetic sensor 90 and are separated from the magnetoresistive effect elements 91 to 98. Further, they are arranged in a row on the one end side in the relative movement direction (X direction).
  • the magnetoresistive elements 91 to 98 and the terminals 99 to 104 are electrically connected to each other through a wiring layer 105 formed of Al or the like to form an A-phase bridge circuit and a B-phase bridge circuit. is doing.
  • the wiring layer 105 is indicated by oblique lines.
  • each of the terminals 99 to 104 is provided at one end side away from the magnetoresistive effect elements 91 to 98 in the vertical direction (Y direction), the vertical dimension W1 of the magnetic sensor 90 is increased.
  • the length dimension of the wiring layer 105 between the terminals 99 to 104 and the magnetoresistive elements 91 to 98 is greatly different due to the routing, so that each of the A-phase bridge circuit and the B-bridge circuit is provided. It is necessary to adjust the aspect ratio of the wiring layer 105 in order to obtain the midpoint potential from the output terminals 101 to 104 provided on the wiring layer 105. At this time, as shown in FIG. 10, the width dimension of the wiring layer 105 cannot be changed greatly in the region where the magnetoresistive effect elements 91 to 98 are formed. Unless a portion where the width of the wiring layer 105 is very wide and a resistance value of the wiring layer 105 is greatly lowered is not provided, it is difficult to adjust the resistance value.
  • a wide wiring layer 105 is extended and formed on the outer side of the magnetoresistive elements 91, 94, 95, and 98 at both ends in the relative movement direction (X direction). Yes. As a result, not only the vertical dimension W1 of the magnetic sensor 90 but also the horizontal dimension L1 in the relative movement direction is increased.
  • the miniaturization of the magnetic sensor 90 cannot be promoted, there is a problem in that the magnet disposed opposite to the magnetic sensor 90 with a space is also required to have a wide shape in the vertical direction, resulting in an increase in manufacturing cost.
  • the present invention is to solve the above-described conventional problems, and in particular, to provide a magnetic sensor and a magnetic encoder capable of realizing downsizing by improving the arrangement of terminals electrically connected to the magnetoresistive effect element. With the goal.
  • the magnetic sensor according to the present invention is disposed at a position away from the magnetized surface of the magnetic field generating member having a magnetized surface in which the N pole and the S pole are alternately magnetized in the relative movement direction.
  • it has a plurality of magnetoresistive effect elements using the magnetoresistive effect whose electric resistance value changes
  • a number of the magnetoresistive effect elements constituting a plurality of bridge circuits are provided on the substrate surface, and the magnetoresistive effect elements are arranged in a matrix in the relative movement direction and in the vertical direction perpendicular to the relative movement direction. Are located in Only one of the input terminal and the ground terminal is provided, and the other terminal is provided in plurality.
  • the input terminal, the ground terminal, and the output terminal are respectively disposed in regions between the magnetoresistive elements arranged in parallel with an interval in the relative movement direction, and the terminals, the magnetoresistive elements, Are electrically connected by a wiring layer to form a plurality of the bridge circuits.
  • each terminal is arranged in a region between the magnetoresistive elements arranged in parallel with a gap in the relative movement direction. Further, only one of the input terminal and the ground terminal is provided, and a plurality of the other terminals are provided.
  • the vertical dimension of the magnetic sensor in the direction orthogonal to the relative movement direction can be effectively reduced as compared with the conventional case.
  • the degree of freedom in routing the wiring layer between the terminal and the magnetoresistive effect element is increased, and the variation in the length of the wiring layer between the terminal and the magnetoresistive effect element can be reduced as compared with the prior art. Therefore, it is not necessary to change the width of the wiring layer extremely in order to match the midpoint potential.
  • both the vertical dimension and the horizontal dimension of the magnetic sensor can be effectively reduced as compared with the prior art, and the magnetic sensor can be downsized.
  • only one of the input terminal and the ground terminal is a central terminal disposed at a substantially central position of the magnetoresistive element forming region, and the other terminal is provided in plural.
  • the output terminals are preferably provided at substantially point-symmetrical positions around the center terminal.
  • the center terminal is an input terminal and the other terminal is a ground terminal.
  • the wiring between the terminals of the external circuit electrically connected to each terminal of the magnetic sensor can be appropriately and easily performed.
  • the first magnetoresistive effect element, the second magnetoresistive effect element, the third magnetoresistive effect element, and the fourth magnetoresistive effect element constitute an A-phase bridge circuit, and The magnetoresistive effect element and the second magnetoresistive effect element are connected in series via the A-phase first output terminal Va1, and the third magnetoresistive effect element and the fourth magnetoresistive effect element are provided.
  • a phase second output terminal Va2 is connected in series, The first magnetoresistive element and the third magnetoresistive element are connected via the input terminal, and the second magnetoresistive element and the fourth magnetoresistive element are connected to the ground terminal.
  • the first magnetoresistive element, the second magnetoresistive element, the third magnetoresistive element, and the fourth magnetoresistive element each have a predetermined center-to-center distance in the relative movement direction.
  • the first magnetoresistive effect element and the fourth magnetoresistive effect element, and the second magnetoresistive effect element and the third magnetoresistive effect element are juxtaposed in a vertical direction perpendicular to the relative movement direction.
  • the fifth magnetoresistive element, the sixth magnetoresistive element, the seventh magnetoresistive element, and the eighth magnetoresistive element constitute a B-phase bridge circuit, and the fifth magnetoresistive element and The sixth magnetoresistive element is connected in series via the B-phase first output terminal Vb1, and the seventh magnetoresistive element and the eighth magnetoresistive element are connected to the B-phase second output. Are connected in series via the terminal Vb2, The fifth magnetoresistive effect element and the seventh magnetoresistive effect element are connected via the input terminal, and the sixth magnetoresistive effect element and the eighth magnetoresistive effect element are connected to the ground terminal.
  • the fifth magnetoresistive effect element, the sixth magnetoresistive effect element, the seventh magnetoresistive effect element, and the eighth magnetoresistive effect element are respectively arranged at a distance in the relative movement direction. And is arranged at a position shifted in the relative movement direction by half the center-to-center distance between the magnetoresistive elements constituting the A-phase bridge circuit,
  • the fifth magnetoresistive effect element and the eighth magnetoresistive effect element, and the sixth magnetoresistive effect element and the seventh magnetoresistive effect element are arranged in parallel in a vertical direction perpendicular to the relative movement direction.
  • the first terminal is a common terminal of one series circuit constituting the A-phase bridge circuit and one series circuit constituting the B-phase bridge circuit.
  • the second terminal is preferably a common terminal of the other series circuit constituting the A-phase bridge circuit and the other series circuit constituting the B-phase bridge circuit.
  • the magnetoresistive effect elements between the magnetoresistive effect elements are arranged in the direction of displacement of the magnetoresistive effect elements constituting the B phase bridge circuit with respect to the magnetoresistive effect elements constituting the A phase bridge circuit.
  • the areas in the relative movement direction are arranged in the order of the first area, the second area, and the third area,
  • the A-phase first output terminal Va1 and the A-phase second output terminal Va2 are both provided in the first region, and the B-phase first output terminal Vb1 and the B-phase second output terminal Vb2 are both the third. It is preferable to arrange in the region.
  • the terminal provided with only one of the input terminal and the ground terminal is a center terminal disposed in the second region, and the A-phase first output terminal Va1;
  • the B-phase first output terminal Vb1 is disposed at a substantially point-symmetrical position with the center terminal as the center, and the A-phase second output terminal Va2 and the B-phase second output terminal Vb2 are centered on the center terminal. It is preferable to arrange at a substantially point-symmetrical position. Thereby, the variation in the length of the wiring layer between the terminal and the magnetoresistive effect element can be more effectively reduced as compared with the conventional case, which can contribute to further miniaturization of the magnetic sensor.
  • two or less wiring layers may be arranged between the magnetoresistive elements arranged in parallel in the vertical direction. Thereby, the width dimension of the magnetic sensor can be reduced more effectively.
  • the magnetic encoder according to the present invention includes any one of the magnetic sensors described above and the magnetic field generating member.
  • miniaturization of the magnetic encoder can be promoted. Further, since the width dimension of the magnetic field generating member can be reduced, the manufacturing cost can be reduced.
  • the pair of magnetoresistive elements connected in series are arranged with a distance between the centers of ⁇ in the relative movement direction. It is preferable that
  • the present invention can be effectively applied to a magnetic encoder in which the center distance between the N pole and the S pole is ⁇ .
  • the size of the magnetic sensor and the magnetic encoder can be reduced as compared with the prior art.
  • FIG. 1 is a perspective view of the magnetic encoder of the present embodiment
  • FIG. 2 is a plan view of the magnetic sensor constituting the magnetic encoder of FIG. 1 (wiring layers are indicated by diagonal lines)
  • FIG. FIG. 4 and FIG. 5 are plan views showing a part of the constituent members of the magnetic sensor shown in FIG. 2, and
  • FIG. 6 explains a terminal arrangement different from FIG.
  • FIG. 7 is a cross-sectional view for explaining a laminated structure of magnetoresistive elements
  • FIG. 8 is a circuit diagram of the magnetic sensor
  • FIG. 9 is a different embodiment from FIG. It is a schematic diagram of a magnetic encoder.
  • the X1-X2 direction is a relative movement direction of the magnet 21 and the magnetic sensor 22.
  • the “relative movement direction” refers to the relative movement direction of the magnetic sensor.
  • the relative movement direction of the magnetic sensor 22 is the X1 direction. Therefore, when the magnet 21 is fixed and the magnetic sensor 22 moves, the magnetic sensor 22 moves in the X1 direction. When the magnetic sensor 22 is fixed and the magnet 21 moves, the magnet 21 moves in the X2 direction. Note that both the magnet 21 and the magnetic sensor 22 may move.
  • the Y1-Y2 direction is the longitudinal direction of the magnetic sensor 22 orthogonal to the relative movement direction.
  • the Z1-Z2 direction is a height direction in which the magnet 21 and the magnetic sensor 22 face each other with a predetermined interval.
  • the magnetic encoder 20 includes a magnet (magnetic field generating member) 21 and a magnetic sensor 22.
  • the magnet 21 has a rod shape extending in the X1-X2 direction shown in the figure, and the surface facing the magnetic sensor 22 is a magnetized surface in which N and S poles are alternately magnetized with a predetermined width in the X1-X2 direction shown in the figure. is there.
  • the center-to-center distance (pitch) between the N pole and the S pole is ⁇ .
  • ⁇ is 0.5 to 4.0 mm.
  • the magnetic sensor 22 includes a substrate 23 and a plurality of magnetoresistive elements 24a to 24h provided on a surface 23a (a surface facing the magnet 21) of the common substrate 23.
  • the eight magnetoresistive elements 24a to 24h are arranged in a matrix form, four in the X1-X2 direction and two in the Y1-Y2 direction. As shown in FIG. 1, the distance between the centers of adjacent magnetoresistive elements in the X1-X2 direction is ⁇ / 2.
  • each of the magnetoresistive effect elements 24a to 24h includes an elongated element portion 12 having an element length L2 longer than an element width W2.
  • the element width W2 is 2 to 20 ⁇ m
  • the element length L2 is 0.05 to 10 mm.
  • the element section 12 has its element length direction in the Y1-Y2 direction shown in the figure, and a plurality of element sections 12 are arranged at predetermined intervals in the X1-X2 direction in the figure. Both end portions in the element length direction of the element portion 12 are connected by the connecting portion 13, and the magnetoresistive effect elements 24a to 24h are formed in a meander shape.
  • the connection portion 13 may be an electrode formed of a good conductor such as nonmagnetic Al or a permanent magnet such as CoPt.
  • the element portion 12 constituting each of the magnetoresistive effect elements 24a to 24h includes an antiferromagnetic layer 7, a fixed magnetic layer 8, a nonmagnetic layer 9, a free magnetic layer 10, and a protective layer 11 from the bottom. It is formed with a structure laminated in order.
  • the stacked structure in FIG. 7 is an example.
  • the antiferromagnetic layer 7 is made of IrMn
  • the pinned magnetic layer 8 is made of CoFe
  • the nonmagnetic layer 9 is made of Cu
  • the free magnetic layer 10 is made of NiFe
  • the protective layer 11 is made of Ta.
  • the element unit 12 includes a laminated portion in which at least the pinned magnetic layer 8 and the free magnetic layer 10 are laminated via the nonmagnetic layer 9.
  • An exchange coupling magnetic field (Hex) is generated between the antiferromagnetic layer 7 and the pinned magnetic layer 8, and the magnetization of the pinned magnetic layer 8 is pinned in one direction.
  • the magnetization direction of the free magnetic layer 10 is not fixed and fluctuates due to the external magnetic field H.
  • the interface between the free magnetic layer 10 and the nonmagnetic layer 9 constituting the element portion 12 faces the plane direction (XY plane direction) parallel to the magnetized surface 21a of the magnet 21. .
  • the above configuration is a configuration of a giant magnetoresistive effect element (GMR element) in which the nonmagnetic layer 9 is formed of Cu.
  • GMR element giant magnetoresistive effect element
  • the nonmagnetic layer 9 is formed of an insulating material such as Al 2 O 3 or MgO.
  • TMR element tunnel type magnetoresistive effect element
  • the magnetoresistive elements 24a to 24h may be anisotropic magnetoresistive elements (AMR elements).
  • the fixed magnetization direction (P direction) of the fixed magnetic layer 8 of each element unit 12 is the relative movement direction (X1 direction).
  • the fixed magnetization direction (P direction) of the fixed magnetic layer 8 may be the X2 direction.
  • the magnetoresistive effect element 24a is the fourth magnetoresistive effect element 24a
  • the magnetoresistive effect element 24b is the sixth magnetoresistive effect element 24b
  • the magnetoresistive effect element 24c is the third magnetoresistive effect element 24c
  • the magnetoresistive effect element 24d is the fifth magnetoresistive effect element 24d
  • the magnetoresistive effect element 24e is the first magnetoresistive effect element 24e
  • the magnetoresistive effect element 24f is the seventh magnetoresistive effect element 24f
  • the magnetoresistive effect element 24g are referred to as a second magnetoresistive element 24g
  • the magnetoresistive element 24h is referred to as an eighth magnetoresistive element 24h.
  • the first magnetoresistive element 24e, the second magnetoresistive element 24g, the third magnetoresistive element 24c, and the fourth magnetoresistive element 24a constitute an A-phase bridge circuit.
  • the first magnetoresistive element 24 e and the second magnetoresistive element 24 g are connected in series via the A-phase first output terminal (Va1) 50.
  • the third magnetoresistive element 24 c and the fourth magnetoresistive element 24 a are connected in series via the A-phase second output terminal (Va 2) 51.
  • first magnetoresistive effect element 24e and the third magnetoresistive effect element 24c are connected via the input terminal 52, and the second magnetoresistive effect element 24g and the fourth magnetoresistive effect element 24a are respectively connected. They are connected via ground terminals 66 and 67.
  • the A-phase first output terminal (Va1) 50 and the A-phase second output terminal (Va2) 51 are connected to the input section side of the first differential amplifier 58, and the first differential amplifier.
  • a differential output can be obtained from 58.
  • another B-phase bridge circuit includes the fifth magnetoresistive element 24d, the sixth magnetoresistive element 24b, the seventh magnetoresistive element 24f, and the eighth magnetoresistive element. 24h.
  • the fifth magnetoresistive effect element 24d and the sixth magnetoresistive effect element 24b are connected in series via the B-phase first output terminal (Vb1) 54, and the seventh magnetoresistive effect element 24f and the eighth magnetoresistive effect element 24b.
  • the resistive effect element 24h is connected in series via the B-phase second output terminal (Vb2) 55. Further, as shown in FIG.
  • the fifth magnetoresistive effect element 24d and the seventh magnetoresistive effect element 24f are connected via the input terminal 52, and the sixth magnetoresistive effect element 24b and the eighth magnetoresistive effect element.
  • the element 24h is connected via ground terminals 66 and 67, respectively.
  • the B-phase first output terminal (Vb1) 54 and the B-phase second output terminal (Vb2) 55 are connected to the input section side of the second differential amplifier 60, and the second differential amplifier. A differential output is obtained from 60.
  • the distance between the centers of magnetoresistive elements connected in series by the bridge circuit shown in FIG. 8 is ⁇ .
  • the external magnetic fields H1 and H2 enter the magnetoresistive elements 24a to 24h from the magnetized surface 21a of the magnet 21.
  • the directions of the external magnetic field H1 and the external magnetic field H2 are different, and when the magnetoresistive effect element is positioned on the magnetic pole, the perpendicular magnetic field is dominant in the magnetic field component with respect to the magnetoresistive effect element. Becomes zero (no magnetic field).
  • the first magnetoresistive element 24e and the second magnetoresistive element 24g are separated from each other by ⁇ in the relative movement direction (X1 direction), when the external magnetic field H1 enters the first magnetoresistive element 24e, the second The external magnetic field H2 enters the magnetoresistive element 24g.
  • the resistance value of the first magnetoresistive effect element 24e increases by the entry of the external magnetic field H1, while the entry of the external magnetic field H2 occurs.
  • the resistance value of the second magnetoresistive element 24g decreases.
  • an output waveform of a substantially triangular wave (or may be a substantially sin wave or a substantially rectangular wave) is obtained.
  • an output waveform of a substantially triangular wave (or a substantially sin wave or a substantially rectangular wave) can be obtained from the B-phase bridge circuit, but the phase is shifted by ⁇ / 2.
  • the moving speed and moving distance of the magnetic sensor 22 or the magnet 21 can be detected. Further, by using two systems of A phase and B phase, it is possible to detect which direction the phase shift direction of the output waveform from the B phase bridge circuit with respect to the output waveform from the A phase bridge circuit is. It becomes possible to know the moving direction.
  • the arrangement of the magnetoresistive effect elements 24a to 24h will be described. This will be described with reference to FIG.
  • the first magnetoresistive effect element 24e and the second magnetoresistive effect element 24g, the third magnetoresistive effect element 24c, and the fourth magnetoresistive effect element 24a connected in series are respectively Arranged at an interval of ⁇ in the relative movement direction (X1 direction).
  • the first magnetoresistive effect element 24e and the fourth magnetoresistive effect element 24a, and the second magnetoresistive effect element 24g and the third magnetoresistive effect element 24c are aligned in the vertical direction (Y1-Y2 direction). It is installed.
  • the first magnetoresistance effect element 24e is on the Y2 side in the X2 direction
  • the second magnetoresistance effect element 24g is on the Y2 side in the X1 direction
  • the third magnetoresistance effect element 24c is in the X1 direction.
  • the fourth magnetoresistive effect element 24a is arranged on the Y1 side in the X2 direction on the Y1 side.
  • the fifth magnetoresistive effect element 24d and the eighth magnetoresistive effect element 24h, and the sixth magnetoresistive effect element 24b and the seventh magnetoresistive effect element 24f are arranged in the vertical direction (Y1-Y2 direction). It is installed.
  • the fifth magnetoresistive element 24d is closer to the X1 side than the third magnetoresistive element 24c
  • the sixth magnetoresistive element 24b is connected to the third magnetoresistive element 24c and the third magnetoresistive element 24c.
  • the second magnetoresistive effect element 24g is disposed on the X1 side.
  • magnetoresistive element formation region first region
  • second region second region
  • third region third region
  • the “magnetoresistive element forming region” is a region including all the magnetoresistive effect elements 24a to 24h, and is an outer edge portion of each magnetoresistive effect element (an edge portion that is not opposed to an adjacent magnetoresistive effect element). ) Is connected by a straight line.
  • the “first region”, “second region”, and “third region” are regions between the magnetoresistive effect elements arranged in parallel with a gap in the relative movement direction (X1 direction in the drawing).
  • the displacement direction of each magnetoresistive effect element constituting the B phase bridge circuit with respect to each magnetoresistive effect element constituting the A phase bridge circuit (in this embodiment, in the X1 direction shown in the figure, which is the same as the relative movement direction of the magnetic sensor)
  • the first region 70, the second region 71, and the third region 72 are arranged in this order. That is, the first region 70 indicates a region surrounded by the first magnetoresistance effect element 24e, the fourth magnetoresistance effect element 24a, the sixth magnetoresistance effect element 24b, and the seventh magnetoresistance effect element 24f.
  • the second region 71 is a region surrounded by the second magnetoresistive element 24g, the third magnetoresistive element 24c, the sixth magnetoresistive element 24b, and the seventh magnetoresistive element 24.
  • the third region 72 indicates a region surrounded by the second magnetoresistive effect element 24g, the third magnetoresistive effect element 24c, the fifth magnetoresistive effect element 24d, and the eighth magnetoresistive effect element 24h. .
  • the input terminal 52 is in the second region 71, and is substantially the horizontal direction (X1-X2 direction) and the vertical direction (Y1-Y2 direction) of the magnetoresistive effect element formation region 75. It is formed at the center position.
  • the “substantially central position” is defined as including a deviation amount of about 0 to 20 ⁇ m from the central position.
  • the center position includes manufacturing errors.
  • Only one input terminal 52 is provided and functions as a common terminal for the A-phase bridge circuit and the B-phase bridge circuit.
  • ground terminals 66 and 67 are provided.
  • the ground terminal 66 is provided in the third region 72, and the ground terminal 67 is provided in the first region 70.
  • the ground terminal 66 is formed at a substantially central position in the lateral direction (X1-X2 direction) of the third region 72, and is formed on the Y2 side when viewed from the input terminal 52.
  • the ground terminal 67 is formed at a substantially central position in the lateral direction (X1-X2 direction) of the first region 70, and is formed on the Y1 side when viewed from the input terminal 52.
  • the ground terminals 66 and 67 are formed at substantially point-symmetrical positions with the input terminal 52 as the center.
  • the “substantially point symmetric position” is defined as including a deviation amount of about 0 to 20 ⁇ m from the point symmetric position.
  • the ground terminal 66 is electrically connected to the second magnetoresistive element 24g constituting the A-phase bridge circuit and the eighth magnetoresistive element 24h constituting the B-phase bridge circuit.
  • the fourth magnetoresistive element 24a constituting the A-phase bridge circuit and the sixth magnetoresistive element 24b constituting the B-phase bridge circuit are electrically connected to the ground terminal 67. .
  • input wiring layers 77 and 78 are formed to extend from the input terminal 52 in the horizontal direction in the figure.
  • the input wiring layer 77 extends in a straight line in the left direction (X2 direction) in the figure, and branches in the middle to form a first magnetoresistive effect element 24e constituting an A phase bridge circuit and a seventh phase constituting a B phase bridge circuit. It is connected to the magnetoresistive effect element 24f.
  • the input wiring layer 78 linearly extends in the right direction (X1 direction) in the drawing, and branches in the middle to constitute the B-phase bridge circuit with the third magnetoresistive effect element 24c constituting the A-phase bridge circuit. It is connected to the fifth magnetoresistive element 24d.
  • a ground wiring layer 79 extends from the ground terminal 66 and is electrically connected to the second magnetoresistive element 24g and the eighth magnetoresistive element 24h.
  • a ground wiring layer 80 extends from the ground terminal 67 and is electrically connected to the fourth magnetoresistive element 24a and the sixth magnetoresistive element 24b.
  • the routing shape of the ground wiring layers 79 and 80 is a substantially rectangular wave shape.
  • both the A-phase first output terminal (Va1) 50 and the A-phase second output terminal (Va2) 51 are formed in the first region 70.
  • the A-phase first output terminal (Va1) 50 and the A-phase second output terminal (Va2) 51 are formed at a substantially central position in the lateral direction (X1-X2 direction) of the first region 70.
  • the B-phase first output terminal (Vb1) 54 and the B-phase second output terminal (Vb2) are both formed in the third region 72.
  • the B-phase first output terminal (Vb1) 54 and the B-phase second output terminal (Vb2) are formed at a substantially central position in the horizontal direction (X1-X2 direction) of the third region 72.
  • a first output wiring layer 81 is formed to extend from the A-phase first output terminal (Va1) 50, and the first magnetoresistive effect element 24e constituting the A-phase bridge circuit is formed. And the second magnetoresistance effect element 24g.
  • a second output wiring layer 82 is formed to extend from the A-phase second output terminal (Va2) 51, and the third magnetoresistive element 24c and the fourth magnetoresistive element constituting the A-phase bridge circuit. It is electrically connected to the effect element 24a.
  • the third output wiring layer 83 is formed to extend from the B-phase first output terminal (Vb1) 54, and the fifth magnetoresistive effect element 24d and the sixth magnetism constituting the B-phase bridge circuit are formed. It is electrically connected to the resistance effect element 24b.
  • the fourth output wiring layer 84 is formed to extend from the B-phase second output terminal (Vb2) 55, and the seventh magnetoresistive element 24f and the eighth magnetoresistive constituting the B-phase bridge circuit. It is electrically connected to the effect element 24h.
  • Each of the wiring layers 77 to 84 described above is formed in a plane on the surface 23a of the substrate 23 via an insulating layer (not shown). In other words, the wiring layers are not laminated with an insulating layer interposed therebetween.
  • the formation surfaces of the wiring layers 77 to 84 may be different from the formation surfaces of the magnetoresistive elements 24a to 24h.
  • the wiring layers 77 to 84 are made of a good conductor such as Al.
  • the magnetic sensor 22 includes a plurality of magnetoresistance effect elements 24a to 24h constituting an A-phase bridge circuit and a B-phase bridge circuit (see FIGS. 1 and 8).
  • the input terminal 52, the ground terminals 66 and 67, and the output terminals 50, 51, 54, and 55 are arranged between the magnetoresistive elements 24a to 24h arranged in parallel with a gap in the relative movement direction (X1 direction). (Refer to FIG. 2, FIG. 4, FIG. 5) of the first region 70, the second region 71, and the third region 72.
  • the vertical dimension W3 of the magnetic sensor 22 can be effectively reduced as compared with the conventional case.
  • the degree of freedom in routing the wiring layer can be improved by the above (3). That is, unlike the present embodiment, when the number of ground terminals is one as with the input terminal 52, the second magnetoresistive effect element 24g, the fourth magnetoresistive effect element 24a, and the sixth Since all of the magnetoresistive effect element 24b and the eighth magnetoresistive effect element 24h must be connected, the degree of freedom of routing of the wiring layer is reduced, and the length of the wiring layer between each magnetoresistive effect element and the ground terminal The dimensional variation becomes very large.
  • the above-described conventional problems can be solved, the degree of freedom of routing of the wiring layer can be improved, and the variation in the length of the wiring layer between each terminal and each magnetoresistive effect element can be made smaller than before. Therefore, it is not necessary to change the width dimension of the wiring layer extremely as in the prior art in order to obtain the midpoint potential from each output terminal 50, 51, 54, 55, and as shown in FIG. 2, FIG. 4, and FIG.
  • the layer can be accommodated almost in the magnetoresistive element formation region 75.
  • the horizontal dimension L3 and the vertical dimension W3 of the magnetic sensor 22 can be made smaller than before, and the miniaturization of the magnetic sensor 22 can be promoted. Therefore, it is possible to promote downsizing of the magnetic encoder 20 and to reduce the vertical dimension of the magnet 21, thereby reducing the manufacturing cost.
  • the horizontal dimension L3 of the magnetic sensor 22 can be in the range of 600 to 4000 ⁇ m, and the vertical dimension W3 of the magnetic sensor 22 can be in the range of 500 to 1000 ⁇ m.
  • the reference resistance values of the magnetoresistive elements 24a to 24h are adjusted to be the same.
  • the arrangement of the terminals electrically connected to the magnetoresistive effect elements 24a to 24h is further improved, and the magnetic sensor 22 and the magnetism are compared with the conventional one without deteriorating the output characteristics. Miniaturization of the encoder 20 can be realized.
  • the input terminal 52 is a central terminal formed at a substantially central position (second region 71) of the magnetoresistive effect element forming region 75.
  • the ground terminals 66 and 67 are formed in the first region 70 and the third region 72, respectively, and are formed at substantially point-symmetrical positions around the input terminal 52.
  • the input terminal 52 is a common terminal for the A-phase bridge circuit and the B-phase bridge circuit.
  • one ground terminal 66 is common to one series circuit constituting the A-phase bridge circuit and one series circuit constituting the B-phase bridge circuit.
  • the other ground terminal 67 is a common terminal of the other series circuit constituting the A-phase bridge circuit and the other series circuit constituting the B-phase bridge circuit (FIGS. 2, 4 and 4). 8).
  • the input terminal 52 is provided at a substantially central position of the magnetoresistive effect element forming region 75, the first magnetoresistive effect element 24e, the third magnetoresistive effect element 24c, the fifth The input wiring layers 77 and 78 up to the magnetoresistive effect element 24d and the seventh magnetoresistive effect element 24f can be easily adjusted so that the lengths thereof are substantially the same.
  • the ground terminals 66 and 67 are provided in the first region 70 and the third region 72, respectively, and are close to the ground terminals 66 and 67 and need to be connected to the ground terminals.
  • phase-side magnetoresistive effect element and the B-phase side magnetoresistive effect element are electrically connected to the ground terminals 66 and 67 via the ground wiring layers 79 and 80, respectively. Therefore, the lengths of the ground wiring layers 79 and 80 from the ground terminals 66 and 67 to the magnetoresistive elements can be easily adjusted so as to be substantially the same.
  • the fifth magnetoresistive effect element 24d, the sixth magnetoresistive effect element 24b, the seventh magnetoresistive effect element 24f, and the eighth magnetoresistive effect element 24h constituting the B-phase bridge circuit are the A phase Are displaced by ⁇ / 2 in the X1 direction (see FIGS. 1 and 2).
  • the regions in the relative movement direction between the magnetoresistive elements are defined as the first region 70, the second region 71, and the third region 72 in the direction of displacement (X1 direction)
  • the A phase The first output terminal (Va1) 50 and the A-phase second output terminal (Va2) 51 are provided in the first region 70, and the B-phase first output terminal (Vb1) 54 and the B-phase second output terminal (Vb2) 55 are provided.
  • the third region 72 see FIG. 5).
  • A-phase first output terminal (Va1) 50 and B-phase first output terminal (Vb1) 54, and A-phase second output terminal (Va2) 51 and B-phase second output terminal (Vb2) 55 are input.
  • the terminal 52 is arranged at a substantially point-symmetrical position (see FIG. 5).
  • the lengths of the output wiring layers 81 to 84 between the output terminals and the magnetoresistive effect elements according to the above (5) and (6) are inferior to the arrangement of the input terminal 52 and the ground terminals 66 and 67 shown in FIG. 4, the lengths of the output wiring layers 81 to 84 between the output terminals and the magnetoresistive effect elements according to the above (5) and (6). Easy to adjust so that dimensional variation is small.
  • both the A-phase first output terminal 50 and the A-phase second output terminal 51 are provided at the substantially central position in the lateral direction of the first region 70, but the variation in the length of the wiring layer is further reduced. As shown in FIG. 6, it is better to form the A-phase first output terminal 50 and the A-phase second output terminal 51 closer to X1 from the substantially central position in the lateral direction of the first region 70. Similarly, the B-phase first output terminal 54 and the B-phase second output terminal 55 are preferably formed closer to X2 from the substantially central position in the lateral direction of the third region 72.
  • the ground terminals and the output terminals are arranged in a row in the vertical direction (Y1-Y2 direction) in each of the first region 70 and the third region 72.
  • the external circuit pads are provided only on the Y2 side as viewed from the magnetic sensor 22, for example, when the magnetic circuit 22 is disposed slightly shifted in the lateral direction (X1-X2 direction), the ground terminal and the output terminal on the magnetic sensor 22 side There is also an effect that it is easy to wire bond between pads on the external circuit side.
  • the length dimensions of the input wiring layers 77 and 78 between the input terminal 52 and each of the magnetoresistive effect elements are obtained by adopting the arrangement of the terminals and the wiring layer routing shown in FIGS.
  • the variations in the length dimension of the ground wiring layers 79 and 80 between the ground terminals 66 and 67 and the magnetoresistive effect elements, and the length dimension of the output wiring layers 81 to 84 between the output terminal and the magnetoresistive effect elements are approximately. It can be less than ⁇ / 2, and the variation in the length dimension of the wiring layer between each magnetoresistive effect element and each terminal can be dramatically reduced as compared with the prior art. Therefore, as shown in FIGS. 2, 4, and 5, it is not necessary to provide a portion where the width dimension of the wiring layer is extremely increased, and further miniaturization of the magnetic sensor 22 can be promoted.
  • Two or less wiring layers are arranged between the magnetoresistive elements arranged in parallel in the vertical direction (Y1-Y2 direction) (see FIG. 2). According to the arrangement of the terminals and the routing of the wiring layers in the present embodiment, two or less wiring layers are arranged between the magnetoresistive elements arranged in parallel in the vertical direction (Y1-Y2 direction). As a result, the vertical dimension W3 of the magnetic sensor 22 can be further reduced, and further downsizing of the magnetic sensor 22 can be promoted.
  • the configuration in which the wiring layer and the terminal partially protrude from the magnetoresistive effect element formation region 75 is not excluded. Actually, in the embodiment of FIG. 2, a part of the wiring layer protrudes from the magnetoresistive element formation region 75. However, the amount of protrusion is sufficiently smaller than that of the prior art. In the present embodiment, it is also possible to arrange the wiring layer and the terminal so as to be all within the magnetoresistive element forming region 75.
  • the magnetic sensor 22 linearly moves relative to the magnet 21 as shown in FIG. 1, but as shown in FIG.
  • a rotary magnetic encoder having a rotating drum 89 and magnetic sensor 22 alternately magnetized with S poles, and capable of detecting the rotation speed, the number of rotations, and the direction of rotation based on the output obtained by the rotation of the rotating drum 89 It may be.
  • FIG. 9 representatively shows a third magnetoresistive element 24c and a fourth magnetoresistive element 24a connected in series.
  • the fixed magnetization direction (P direction) of the fixed magnetic layer 8 of each of the magnetoresistive effect elements 24 a to 24 h is the contact point on the center of the substrate 23 of the magnetic sensor 22 in the relative rotation direction of the magnetic sensor 22. Is fixed in a direction parallel to the tangential direction (relative movement direction of the magnetic sensor 22).
  • FIG. 1 is a plan view of a magnetic sensor constituting the magnetic encoder of FIG. An enlarged plan view of a magnetoresistive effect element constituting a magnetic sensor
  • FIG. 3 is a plan view showing an excerpt of some of the constituent members of the magnetic sensor shown in FIG.
  • FIG. 3 is a plan view showing an excerpt of some of the constituent members of the magnetic sensor shown in FIG.
  • the partial top view of the magnetic sensor for demonstrating terminal arrangement different from FIG. Sectional drawing for demonstrating the laminated structure of a magnetoresistive effect element, Circuit diagram of magnetic sensor
  • FIG. 1 is a schematic diagram of a magnetic encoder of the present embodiment different from FIG.
  • the top view of the magnetic sensor which comprises the conventional magnetic encoder

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Abstract

[PROBLEMS] To provide a magnetic sensor and magnetic encoder in which down sizing is realized by improving the layout of terminals connected electrically with magnetoresistance effect elements in particular. [MEANS FOR SOLVING PROBLEMS] The magnetoresistance effect elements (24a to 24h) are arranged in matrix in a relative movement direction (direction X1) and in a vertical direction (direction Y1-Y2) orthogonal to the relative movement direction. One input terminal (52) and two ground terminals (66, 67) are provided. The input terminal (52), the ground terminal (66) and output terminals (50, 51, 54, 55) are respectively arranged in areas (70, 71, 72) among the respective magnetoresistance effect elements arranged side by side and spaced in the relative movement direction. The respective terminals and the respective magnetoresistance effect elements are connected electrically through wiring layers (shown by shading) to constitute two bridge circuits of A-phase and B-phase.

Description

磁気センサ及び磁気エンコーダMagnetic sensor and magnetic encoder
　本発明は、特に、磁気抵抗効果素子と電気的に接続される端子の配置を改良し小型化を実現できる磁気センサ及び磁気エンコーダに関する。 The present invention particularly relates to a magnetic sensor and a magnetic encoder capable of improving the arrangement of terminals electrically connected to a magnetoresistive effect element and realizing miniaturization.
　巨大磁気抵抗効果（ＧＭＲ効果）を利用した磁気抵抗効果素子（ＧＭＲ素子）は、磁気エンコーダに使用できる。 A magnetoresistive element (GMR element) using a giant magnetoresistive effect (GMR effect) can be used for a magnetic encoder.
　図１０は、従来における磁気エンコーダを構成する磁気センサ９０の平面図である。磁気抵抗効果素子９１～９８は、８個設けられ、４個ずつ磁気抵抗効果素子を組み合わせてＡ相のブリッジ回路とＢ相のブリッジ回路を構成している。 FIG. 10 is a plan view of a magnetic sensor 90 constituting a conventional magnetic encoder. Eight magnetoresistive effect elements 91 to 98 are provided, and each of the four magnetoresistive effect elements is combined to constitute an A-phase bridge circuit and a B-phase bridge circuit.
　図１０に示す磁気センサ９０では、入力端子９９及びグランド端子１００は夫々１個ずつ設けられている。入力端子９９及びグランド端子１００は、Ａ相のブリッジ回路及びＢ相のブリッジ回路に対する共通端子である。 In the magnetic sensor 90 shown in FIG. 10, one input terminal 99 and one ground terminal 100 are provided. The input terminal 99 and the ground terminal 100 are common terminals for the A-phase bridge circuit and the B-phase bridge circuit.
　またＡ相のブリッジ回路を構成する２個の出力端子１０１，１０２と、Ｂ相のブリッジ回路を構成する２個の出力端子１０３，１０４が設けられる。 Further, two output terminals 101 and 102 constituting the A phase bridge circuit and two output terminals 103 and 104 constituting the B phase bridge circuit are provided.
　入力端子９９、グランド端子１００、及び出力端子１０１～１０４は、磁気センサ９０の相対移動方向（Ｘ方向）に対して直交する縦方向（Ｙ方向）であって磁気抵抗効果素子９１～９８から離れた一端部側に相対移動方向（Ｘ方向）に向けて一列に配列されている。 The input terminal 99, the ground terminal 100, and the output terminals 101 to 104 are in the vertical direction (Y direction) orthogonal to the relative movement direction (X direction) of the magnetic sensor 90 and are separated from the magnetoresistive effect elements 91 to 98. Further, they are arranged in a row on the one end side in the relative movement direction (X direction).
　そして各磁気抵抗効果素子９１～９８と各端子９９～１０４とがＡｌ等で形成された配線層１０５を介して電気的に接続されており、Ａ相のブリッジ回路及びＢ相のブリッジ回路を構成している。図１０では配線層１０５を斜線で示している。
US2001/0020847A1 US006020738 特開平１１－５１６９４号公報 特開平１１－５１６９５号公報 The magnetoresistive elements 91 to 98 and the terminals 99 to 104 are electrically connected to each other through a wiring layer 105 formed of Al or the like to form an A-phase bridge circuit and a B-phase bridge circuit. is doing. In FIG. 10, the wiring layer 105 is indicated by oblique lines.
US2001 / 0020847A1 US006020738 JP 11-51694 A Japanese Patent Laid-Open No. 11-51695
　しかしながら、図１０に示す従来の磁気エンコーダを構成する磁気センサ９０の構造では以下に示すように小型化が困難であった。 However, it is difficult to reduce the size of the structure of the magnetic sensor 90 constituting the conventional magnetic encoder shown in FIG.
　すなわち各端子９９～１０４が磁気抵抗効果素子９１～９８から縦方向（Ｙ方向）に離れた一端部側に片寄って設けられているため、磁気センサ９０の縦寸法Ｗ１が大きくなった。 That is, since each of the terminals 99 to 104 is provided at one end side away from the magnetoresistive effect elements 91 to 98 in the vertical direction (Y direction), the vertical dimension W1 of the magnetic sensor 90 is increased.
　また、各端子９９～１０４と各磁気抵抗効果素子９１～９８間の配線層１０５の長さ寸法が引き回しの関係上、大きく異なってしまうため、Ａ相のブリッジ回路、及びＢのブリッジ回路の夫々に設けられた出力端子１０１～１０４から中点電位を得るために配線層１０５のアスペクト比の調整が必要であった。このとき図１０に示すように、磁気抵抗効果素子９１～９８が形成されている領域内では、配線層１０５の幅寸法を大きく変えることができないため、どうしても磁気抵抗効果素子９１～９８の形成領域外で配線層１０５の幅の一部を非常に広くして配線層１０５の抵抗値を大幅に下げる箇所を設けないと、抵抗値の合わせ込みが難しかった。また、図１０に示す磁気センサ９０では、相対移動方向（Ｘ方向）の両端にある磁気抵抗効果素子９１，９４，９５，９８よりもさらに外側に幅の広い配線層１０５が延出形成されている。これにより、磁気センサ９０の縦寸法Ｗ１のみならず相対移動方向への横寸法Ｌ１も大きくなった。 In addition, the length dimension of the wiring layer 105 between the terminals 99 to 104 and the magnetoresistive elements 91 to 98 is greatly different due to the routing, so that each of the A-phase bridge circuit and the B-bridge circuit is provided. It is necessary to adjust the aspect ratio of the wiring layer 105 in order to obtain the midpoint potential from the output terminals 101 to 104 provided on the wiring layer 105. At this time, as shown in FIG. 10, the width dimension of the wiring layer 105 cannot be changed greatly in the region where the magnetoresistive effect elements 91 to 98 are formed. Unless a portion where the width of the wiring layer 105 is very wide and a resistance value of the wiring layer 105 is greatly lowered is not provided, it is difficult to adjust the resistance value. In addition, in the magnetic sensor 90 shown in FIG. 10, a wide wiring layer 105 is extended and formed on the outer side of the magnetoresistive elements 91, 94, 95, and 98 at both ends in the relative movement direction (X direction). Yes. As a result, not only the vertical dimension W1 of the magnetic sensor 90 but also the horizontal dimension L1 in the relative movement direction is increased.
　また、図１０の従来の配置構成では、配線層１０５の引き回しの関係上、縦方向（Ｙ方向）に並設された磁気抵抗効果素子９１～９８間に３本以上の配線層１０５を介在させる箇所が出てしまうため、縦方向（Ｙ方向）に並設された磁気抵抗効果素子９１～９８間の間隔Ｔ１を広くしないといけなかった。
　以上の理由により、従来の配置では磁気センサ９０の小型化が困難であった。 In the conventional arrangement shown in FIG. 10, three or more wiring layers 105 are interposed between the magnetoresistive effect elements 91 to 98 arranged in parallel in the vertical direction (Y direction) due to the routing of the wiring layer 105. Since a portion appears, the interval T1 between the magnetoresistive elements 91 to 98 arranged in parallel in the vertical direction (Y direction) must be widened.
For the above reasons, it is difficult to reduce the size of the magnetic sensor 90 with the conventional arrangement.
　また磁気センサ９０の小型化を促進できないため、磁気センサ９０と間隔を空けて対向配置される磁石も縦方向に広い形状としなければならず製造コストが上昇する問題があった。 Further, since the miniaturization of the magnetic sensor 90 cannot be promoted, there is a problem in that the magnet disposed opposite to the magnetic sensor 90 with a space is also required to have a wide shape in the vertical direction, resulting in an increase in manufacturing cost.
　上記に挙げた各特許文献では、Ａ相とＢ相の２つのブリッジ回路を持つ磁気エンコーダにおける上記の課題認識はなく、それを解決する手段も当然のことながら示されていない。 In each of the patent documents listed above, there is no recognition of the above problem in a magnetic encoder having two bridge circuits of A phase and B phase, and naturally no means for solving it is shown.
　そこで本発明は上記従来の課題を解決するためのものであり、特に、磁気抵抗効果素子と電気的に接続される端子の配置を改良し小型化を実現できる磁気センサ及び磁気エンコーダを提供することを目的とする。 Accordingly, the present invention is to solve the above-described conventional problems, and in particular, to provide a magnetic sensor and a magnetic encoder capable of realizing downsizing by improving the arrangement of terminals electrically connected to the magnetoresistive effect element. With the goal.
　本発明における磁気センサは、相対移動方向に交互にＮ極とＳ極が着磁された着磁面を有する磁界発生部材の前記着磁面から離れた位置に配置され、基板表面に外部磁界に対して電気抵抗値が変化する磁気抵抗効果を利用した複数個の磁気抵抗効果素子を有しており、
　複数のブリッジ回路を構成する数の前記磁気抵抗効果素子が前記基板表面に設けられており、前記磁気抵抗効果素子は、前記相対移動方向、及び前記相対移動方向と直交する縦方向に、マトリクス状に配置されており、
　入力端子及びグランド端子のうちいずれか一方の端子が１個だけ設けられ、他方の端子が複数設けられており、
　前記入力端子、前記グランド端子、及び出力端子が、夫々、前記相対移動方向に間隔を空けて並設された各磁気抵抗効果素子の間の領域に配置され、各端子と各磁気抵抗効果素子とが配線層で電気的に接続されて複数の前記ブリッジ回路を構成していることを特徴とするものである。 The magnetic sensor according to the present invention is disposed at a position away from the magnetized surface of the magnetic field generating member having a magnetized surface in which the N pole and the S pole are alternately magnetized in the relative movement direction. On the other hand, it has a plurality of magnetoresistive effect elements using the magnetoresistive effect whose electric resistance value changes
A number of the magnetoresistive effect elements constituting a plurality of bridge circuits are provided on the substrate surface, and the magnetoresistive effect elements are arranged in a matrix in the relative movement direction and in the vertical direction perpendicular to the relative movement direction. Are located in
Only one of the input terminal and the ground terminal is provided, and the other terminal is provided in plurality.
The input terminal, the ground terminal, and the output terminal are respectively disposed in regions between the magnetoresistive elements arranged in parallel with an interval in the relative movement direction, and the terminals, the magnetoresistive elements, Are electrically connected by a wiring layer to form a plurality of the bridge circuits.
　上記したように、各端子が、相対移動方向に間隔を空けて並設された各磁気抵抗効果素子の間の領域内に配置されている。また、入力端子及びグランド端子のうちいずれか一方の端子が１個だけ設けられ、他方の端子が複数設けられる。これにより、相対移動方向に直交する方向の磁気センサの縦寸法を従来に比べて効果的に小さくできる。しかも、端子と磁気抵抗効果素子間の配線層の引き回しの自由度が高くなり、端子と磁気抵抗効果素子間の配線層の長さのばらつきを従来よりも小さくできる。したがって、中点電位を合わせるべく極端に配線層の幅を変える必要もない。以上により、本発明によれば従来に比べて磁気センサの縦寸法及び横寸法の双方を効果的に小さくでき、磁気センサの小型化を実現できる。 As described above, each terminal is arranged in a region between the magnetoresistive elements arranged in parallel with a gap in the relative movement direction. Further, only one of the input terminal and the ground terminal is provided, and a plurality of the other terminals are provided. Thereby, the vertical dimension of the magnetic sensor in the direction orthogonal to the relative movement direction can be effectively reduced as compared with the conventional case. In addition, the degree of freedom in routing the wiring layer between the terminal and the magnetoresistive effect element is increased, and the variation in the length of the wiring layer between the terminal and the magnetoresistive effect element can be reduced as compared with the prior art. Therefore, it is not necessary to change the width of the wiring layer extremely in order to match the midpoint potential. As described above, according to the present invention, both the vertical dimension and the horizontal dimension of the magnetic sensor can be effectively reduced as compared with the prior art, and the magnetic sensor can be downsized.
　本発明では、前記入力端子及び前記グランド端子のうち１個だけ設けられたほうの端子が磁気抵抗効果素子形成領域の略中心位置に配置される中心端子であり、複数設けられる他方の端子、及び前記出力端子は、夫々、前記中心端子を中心として略点対称の位置に設けられることが好ましい。これにより、より効果的に、端子と磁気抵抗効果素子間の配線層の長さのばらつきを従来よりも小さくでき、磁気センサの更なる小型化に寄与できる。 In the present invention, only one of the input terminal and the ground terminal is a central terminal disposed at a substantially central position of the magnetoresistive element forming region, and the other terminal is provided in plural. The output terminals are preferably provided at substantially point-symmetrical positions around the center terminal. Thereby, the variation in the length of the wiring layer between the terminal and the magnetoresistive effect element can be more effectively reduced as compared with the conventional case, which can contribute to further miniaturization of the magnetic sensor.
　また本発明では、前記中心端子は入力端子で、他方の端子がグランド端子であることが好ましい。これにより磁気センサの各端子と電気的に接続される外部回路の端子間の配線を適切且つ容易にできる。 In the present invention, it is preferable that the center terminal is an input terminal and the other terminal is a ground terminal. Thereby, the wiring between the terminals of the external circuit electrically connected to each terminal of the magnetic sensor can be appropriately and easily performed.
　また本発明では、第１の磁気抵抗効果素子、第２の磁気抵抗効果素子、第３の磁気抵抗効果素子及び第４の磁気抵抗効果素子がＡ相のブリッジ回路を構成し、前記第１の磁気抵抗効果素子と前記第２の磁気抵抗効果素子とがＡ相第１出力端子Ｖａ１を介して直列接続されるとともに、前記第３の磁気抵抗効果素子と前記第４の磁気抵抗効果素子とがＡ相第２出力端子Ｖａ２を介して直列接続されており、
　前記第１の磁気抵抗効果素子と前記第３の磁気抵抗効果素子とが前記入力端子を介して接続され、前記第２の磁気抵抗効果素子と前記第４の磁気抵抗効果素子とが前記グランド端子を介して接続されており、
　前記第１の磁気抵抗効果素子と前記第２の磁気抵抗効果素子、及び第３の磁気抵抗効果素子及び第４の磁気抵抗効果素子が、夫々、前記相対移動方向に、所定の中心間距離を空けて配置されているとともに、
　前記第１の磁気抵抗効果素子と前記第４の磁気抵抗効果素子、及び第２の磁気抵抗効果素子と前記第３の磁気抵抗効果素子が、前記相対移動方向と直交する縦方向に並設されており、
　第５の磁気抵抗効果素子、第６の磁気抵抗効果素子、第７の磁気抵抗効果素子及び第８の磁気抵抗効果素子がＢ相のブリッジ回路を構成し、前記第５の磁気抵抗効果素子と前記第６の磁気抵抗効果素子とがＢ相第１出力端子Ｖｂ１を介して直列接続されるとともに、前記第７の磁気抵抗効果素子と前記第８の磁気抵抗効果素子とがＢ相第２出力端子Ｖｂ２を介して直列接続されており、
　前記第５の磁気抵抗効果素子と前記第７の磁気抵抗効果素子とが前記入力端子を介して接続され、前記第６の磁気抵抗効果素子と前記第８の磁気抵抗効果素子とが前記グランド端子を介して接続されており、
　前記第５の磁気抵抗効果素子と前記第６の磁気抵抗効果素子、及び第７の磁気抵抗効果素子及び第８の磁気抵抗効果素子が、夫々、前記相対移動方向に距離を空けて配置されているとともに、前記Ａ相のブリッジ回路を構成する各磁気抵抗効果素子間の中心間距離の半分だけ前記相対移動方向にずれた位置に配置され、さらに、
　前記第５の磁気抵抗効果素子と前記第８の磁気抵抗効果素子、及び前記第６の磁気抵抗効果素子と前記第７の磁気抵抗効果素子が、前記相対移動方向と直交する縦方向に並設されており、
　前記入力端子及び前記グランド端子のうち１個だけ設けられたほうの端子が前記Ａ相のブリッジ回路及び前記Ｂ相のブリッジ回路に対する共通端子であり、他方の端子は２個設けられており、前記他方の端子のうち第１の端子は、Ａ相のブリッジ回路を構成する一方の直列回路、及びＢ相のブリッジ回路を構成する一方の直列回路の共通端子であり、前記他方の端子のうち第２の端子は、Ａ相のブリッジ回路を構成する他方の直列回路、及びＢ相のブリッジ回路を構成する他方の直列回路の共通端子であることが好ましい。本発明を、Ａ相のブリッジ回路及びＢ相のブリッジ回路を構成する磁気抵抗効果素子が上記した配置からなる磁気センサに適用することで、磁気センサの小型化を効果的に促進できる。 In the present invention, the first magnetoresistive effect element, the second magnetoresistive effect element, the third magnetoresistive effect element, and the fourth magnetoresistive effect element constitute an A-phase bridge circuit, and The magnetoresistive effect element and the second magnetoresistive effect element are connected in series via the A-phase first output terminal Va1, and the third magnetoresistive effect element and the fourth magnetoresistive effect element are provided. A phase second output terminal Va2 is connected in series,
The first magnetoresistive element and the third magnetoresistive element are connected via the input terminal, and the second magnetoresistive element and the fourth magnetoresistive element are connected to the ground terminal. Connected through
The first magnetoresistive element, the second magnetoresistive element, the third magnetoresistive element, and the fourth magnetoresistive element each have a predetermined center-to-center distance in the relative movement direction. As well as being arranged
The first magnetoresistive effect element and the fourth magnetoresistive effect element, and the second magnetoresistive effect element and the third magnetoresistive effect element are juxtaposed in a vertical direction perpendicular to the relative movement direction. And
The fifth magnetoresistive element, the sixth magnetoresistive element, the seventh magnetoresistive element, and the eighth magnetoresistive element constitute a B-phase bridge circuit, and the fifth magnetoresistive element and The sixth magnetoresistive element is connected in series via the B-phase first output terminal Vb1, and the seventh magnetoresistive element and the eighth magnetoresistive element are connected to the B-phase second output. Are connected in series via the terminal Vb2,
The fifth magnetoresistive effect element and the seventh magnetoresistive effect element are connected via the input terminal, and the sixth magnetoresistive effect element and the eighth magnetoresistive effect element are connected to the ground terminal. Connected through
The fifth magnetoresistive effect element, the sixth magnetoresistive effect element, the seventh magnetoresistive effect element, and the eighth magnetoresistive effect element are respectively arranged at a distance in the relative movement direction. And is arranged at a position shifted in the relative movement direction by half the center-to-center distance between the magnetoresistive elements constituting the A-phase bridge circuit,
The fifth magnetoresistive effect element and the eighth magnetoresistive effect element, and the sixth magnetoresistive effect element and the seventh magnetoresistive effect element are arranged in parallel in a vertical direction perpendicular to the relative movement direction. Has been
Of the input terminal and the ground terminal, only one terminal is a common terminal for the A-phase bridge circuit and the B-phase bridge circuit, and the other terminal is provided in two, Of the other terminals, the first terminal is a common terminal of one series circuit constituting the A-phase bridge circuit and one series circuit constituting the B-phase bridge circuit. The second terminal is preferably a common terminal of the other series circuit constituting the A-phase bridge circuit and the other series circuit constituting the B-phase bridge circuit. By applying the present invention to a magnetic sensor in which the magnetoresistive effect elements constituting the A-phase bridge circuit and the B-phase bridge circuit are arranged as described above, the downsizing of the magnetic sensor can be effectively promoted.
　また本発明では、前記Ａ相のブリッジ回路を構成する各磁気抵抗効果素子に対する前記Ｂ相のブリッジ回路を構成する各磁気抵抗効果素子のずれ方向に向けて、各磁気抵抗効果素子の間の前記相対移動方向への領域が、第１の領域、第２の領域及び第３の領域の順に並設されており、
　前記Ａ相第１出力端子Ｖａ１と前記Ａ相第２出力端子Ｖａ２が共に前記第１の領域に設けられ、前記Ｂ相第１出力端子Ｖｂ１及び前記Ｂ相第２出力端子Ｖｂ２が共に前記第３の領域に配置されることが好ましい。 In the present invention, the magnetoresistive effect elements between the magnetoresistive effect elements are arranged in the direction of displacement of the magnetoresistive effect elements constituting the B phase bridge circuit with respect to the magnetoresistive effect elements constituting the A phase bridge circuit. The areas in the relative movement direction are arranged in the order of the first area, the second area, and the third area,
The A-phase first output terminal Va1 and the A-phase second output terminal Va2 are both provided in the first region, and the B-phase first output terminal Vb1 and the B-phase second output terminal Vb2 are both the third. It is preferable to arrange in the region.
　これにより、より効果的に、端子と磁気抵抗効果素子間の配線層の長さのばらつきを従来よりも小さくでき、磁気センサの更なる小型化に寄与できる。 This makes it possible to more effectively reduce the variation in the length of the wiring layer between the terminal and the magnetoresistive effect element than before, and contribute to further miniaturization of the magnetic sensor.
　また本発明では、前記入力端子及び前記グランド端子のうち１個だけ設けられたほうの端子が前記第２の領域内に配置される中心端子であり、前記Ａ相第１出力端子Ｖａ１と、前記Ｂ相第１出力端子Ｖｂ１とが前記中心端子を中心として略点対称の位置に配置され、前記Ａ相第２出力端子Ｖａ２と、前記Ｂ相第２出力端子Ｖｂ２とが前記中心端子を中心として略点対称の位置に配置されていることが好ましい。これにより、より効果的に、端子と磁気抵抗効果素子間の配線層の長さのばらつきを従来よりも小さくでき、磁気センサの更なる小型化に寄与できる。 Further, in the present invention, the terminal provided with only one of the input terminal and the ground terminal is a center terminal disposed in the second region, and the A-phase first output terminal Va1; The B-phase first output terminal Vb1 is disposed at a substantially point-symmetrical position with the center terminal as the center, and the A-phase second output terminal Va2 and the B-phase second output terminal Vb2 are centered on the center terminal. It is preferable to arrange at a substantially point-symmetrical position. Thereby, the variation in the length of the wiring layer between the terminal and the magnetoresistive effect element can be more effectively reduced as compared with the conventional case, which can contribute to further miniaturization of the magnetic sensor.
　また本発明では、前記縦方向に並設された各磁気抵抗効果素子の間には、２本以下の前記配線層が配置される構成にできる。これにより、磁気センサの幅寸法をより効果的に小さくできる。 In the present invention, two or less wiring layers may be arranged between the magnetoresistive elements arranged in parallel in the vertical direction. Thereby, the width dimension of the magnetic sensor can be reduced more effectively.
　また本発明における磁気エンコーダは、上記のいずれかに記載された磁気センサと、前記磁界発生部材とを有してなることを特徴とするものである。本発明では、磁気エンコーダの小型化を促進できる。また磁界発生部材の幅寸法を小さくできるので、製造コストを低減することが出来る。 The magnetic encoder according to the present invention includes any one of the magnetic sensors described above and the magnetic field generating member. In the present invention, miniaturization of the magnetic encoder can be promoted. Further, since the width dimension of the magnetic field generating member can be reduced, the manufacturing cost can be reduced.
　また本発明では、前記Ｎ極と前記Ｓ極の中心間距離をλとしたとき、直列接続される一対の前記磁気抵抗効果素子は、前記相対移動方向に、λの中心間距離を空けて配置されていることが好ましい。 Also, in the present invention, when the distance between the centers of the N pole and the S pole is λ, the pair of magnetoresistive elements connected in series are arranged with a distance between the centers of λ in the relative movement direction. It is preferable that
　本発明は、Ｎ極とＳ極間の中心間距離をλとした磁気エンコーダに効果的に適用できる。 The present invention can be effectively applied to a magnetic encoder in which the center distance between the N pole and the S pole is λ.
　本発明によれば、従来に比べて、磁気センサ及び磁気エンコーダの小型化を実現できる。 According to the present invention, the size of the magnetic sensor and the magnetic encoder can be reduced as compared with the prior art.
　図１は、本実施形態の磁気エンコーダの斜視図、図２は、図１の磁気エンコーダを構成する磁気センサの平面図（配線層を斜線で示した）、図３は磁気センサを構成する磁気抵抗効果素子の拡大平面図、図４、図５は、図２に示す磁気センサの構成部材の一部を抜粋して示した平面図、図６は、図２とは異なる端子配置を説明するための磁気センサの部分平面図、図７は、磁気抵抗効果素子の積層構造を説明するための断面図、図８は、磁気センサの回路図、図９は、図１とは異なる本実施形態の磁気エンコーダの模式図、である。 FIG. 1 is a perspective view of the magnetic encoder of the present embodiment, FIG. 2 is a plan view of the magnetic sensor constituting the magnetic encoder of FIG. 1 (wiring layers are indicated by diagonal lines), and FIG. FIG. 4 and FIG. 5 are plan views showing a part of the constituent members of the magnetic sensor shown in FIG. 2, and FIG. 6 explains a terminal arrangement different from FIG. FIG. 7 is a cross-sectional view for explaining a laminated structure of magnetoresistive elements, FIG. 8 is a circuit diagram of the magnetic sensor, and FIG. 9 is a different embodiment from FIG. It is a schematic diagram of a magnetic encoder.
　各図におけるＸ１－Ｘ２方向、Ｙ１－Ｙ２方向、及びＺ１－Ｚ２方向の各方向は残り２つの方向に対して直交した関係となっている。Ｘ１－Ｘ２方向は、磁石２１及び磁気センサ２２の相対移動方向である。この実施形態において特に断らない限り「相対移動方向」とは磁気センサの相対移動方向を指す。そしてこの実施形態では、磁気センサ２２の相対移動方向はＸ１方向である。よって、磁石２１が固定で磁気センサ２２が移動する場合は、磁気センサ２２はＸ１方向に動き、磁気センサ２２が固定で磁石２１が移動する場合は、磁石２１がＸ２方向に動いている。なお磁石２１及び磁気センサ２２の双方が動く形態でもよい。Ｙ１－Ｙ２方向は、相対移動方向に対して直交する磁気センサ２２の縦方向である。Ｚ１－Ｚ２方向は磁石２１と磁気センサ２２とが所定の間隔を空けて対向する高さ方向である。 In each figure, the X1-X2 direction, the Y1-Y2 direction, and the Z1-Z2 direction are orthogonal to the remaining two directions. The X1-X2 direction is a relative movement direction of the magnet 21 and the magnetic sensor 22. In this embodiment, unless otherwise specified, the “relative movement direction” refers to the relative movement direction of the magnetic sensor. In this embodiment, the relative movement direction of the magnetic sensor 22 is the X1 direction. Therefore, when the magnet 21 is fixed and the magnetic sensor 22 moves, the magnetic sensor 22 moves in the X1 direction. When the magnetic sensor 22 is fixed and the magnet 21 moves, the magnet 21 moves in the X2 direction. Note that both the magnet 21 and the magnetic sensor 22 may move. The Y1-Y2 direction is the longitudinal direction of the magnetic sensor 22 orthogonal to the relative movement direction. The Z1-Z2 direction is a height direction in which the magnet 21 and the magnetic sensor 22 face each other with a predetermined interval.
　図１に示すように磁気エンコーダ２０は、磁石（磁界発生部材）２１と磁気センサ２２を有して構成される。 As shown in FIG. 1, the magnetic encoder 20 includes a magnet (magnetic field generating member) 21 and a magnetic sensor 22.
　磁石２１は図示Ｘ１－Ｘ２方向に延びる棒形状であり、磁気センサ２２との対向面が図示Ｘ１－Ｘ２方向に所定幅にてＮ極とＳ極とが交互に着磁された着磁面である。Ｎ極とＳ極との中心間距離（ピッチ）はλである。例えば、λは、０．５～４．０ｍｍである。 The magnet 21 has a rod shape extending in the X1-X2 direction shown in the figure, and the surface facing the magnetic sensor 22 is a magnetized surface in which N and S poles are alternately magnetized with a predetermined width in the X1-X2 direction shown in the figure. is there. The center-to-center distance (pitch) between the N pole and the S pole is λ. For example, λ is 0.5 to 4.0 mm.
　図１に示すように磁気センサ２２は、基板２３と、共通の基板２３の表面（磁石２１との対向面）２３ａに設けられた複数の磁気抵抗効果素子２４ａ～２４ｈとを有して構成される。 As shown in FIG. 1, the magnetic sensor 22 includes a substrate 23 and a plurality of magnetoresistive elements 24a to 24h provided on a surface 23a (a surface facing the magnet 21) of the common substrate 23. The
　図１及び図２に示すように、８個の磁気抵抗効果素子２４ａ～２４ｈは、Ｘ１－Ｘ２方向に４個ずつ、Ｙ１－Ｙ２方向に２個ずつマトリクス状に配列している。図１に示すようにＸ１－Ｘ２方向にて隣り合う各磁気抵抗効果素子の中心間の間隔はλ／２となっている。 As shown in FIG. 1 and FIG. 2, the eight magnetoresistive elements 24a to 24h are arranged in a matrix form, four in the X1-X2 direction and two in the Y1-Y2 direction. As shown in FIG. 1, the distance between the centers of adjacent magnetoresistive elements in the X1-X2 direction is λ / 2.
　図３に示すように、各磁気抵抗効果素子２４ａ～２４ｈは、素子幅Ｗ２に比べて素子長さＬ２が長い細長形状の素子部１２を備える。例えば素子幅Ｗ２は、２～２０μｍで、素子長さＬ２は０．０５～１０ｍｍである。素子部１２は、その素子長さ方向が図示Ｙ１－Ｙ２方向を向き、複数の素子部１２が図示Ｘ１－Ｘ２方向に所定間隔を空けて配置される。素子部１２の素子長さ方向の両端部同士が接続部１３により接続されて磁気抵抗効果素子２４ａ～２４ｈはミアンダ形状で形成される。接続部１３は非磁性のＡｌ等の良導体で形成された電極であっても、ＣｏＰｔ等の永久磁石で形成されてもよい。 As shown in FIG. 3, each of the magnetoresistive effect elements 24a to 24h includes an elongated element portion 12 having an element length L2 longer than an element width W2. For example, the element width W2 is 2 to 20 μm, and the element length L2 is 0.05 to 10 mm. The element section 12 has its element length direction in the Y1-Y2 direction shown in the figure, and a plurality of element sections 12 are arranged at predetermined intervals in the X1-X2 direction in the figure. Both end portions in the element length direction of the element portion 12 are connected by the connecting portion 13, and the magnetoresistive effect elements 24a to 24h are formed in a meander shape. The connection portion 13 may be an electrode formed of a good conductor such as nonmagnetic Al or a permanent magnet such as CoPt.
　各磁気抵抗効果素子２４ａ～２４ｈを構成する素子部１２は、図７に示すように、下から反強磁性層７、固定磁性層８、非磁性層９、フリー磁性層１０及び保護層１１の順で積層された構造で形成される。ただし、図７の積層構造は一例である。例えば反強磁性層７はＩｒＭｎ、固定磁性層８はＣｏＦｅ、非磁性層９はＣｕ、フリー磁性層１０はＮｉＦｅ、保護層１１はＴａで形成される。 As shown in FIG. 7, the element portion 12 constituting each of the magnetoresistive effect elements 24a to 24h includes an antiferromagnetic layer 7, a fixed magnetic layer 8, a nonmagnetic layer 9, a free magnetic layer 10, and a protective layer 11 from the bottom. It is formed with a structure laminated in order. However, the stacked structure in FIG. 7 is an example. For example, the antiferromagnetic layer 7 is made of IrMn, the pinned magnetic layer 8 is made of CoFe, the nonmagnetic layer 9 is made of Cu, the free magnetic layer 10 is made of NiFe, and the protective layer 11 is made of Ta.
　素子部１２は、少なくとも固定磁性層８とフリー磁性層１０が非磁性層９を介して積層された積層部分を備える。反強磁性層７と固定磁性層８との間には交換結合磁界（Ｈｅｘ）が生じて固定磁性層８の磁化は一方向に固定されている。 The element unit 12 includes a laminated portion in which at least the pinned magnetic layer 8 and the free magnetic layer 10 are laminated via the nonmagnetic layer 9. An exchange coupling magnetic field (Hex) is generated between the antiferromagnetic layer 7 and the pinned magnetic layer 8, and the magnetization of the pinned magnetic layer 8 is pinned in one direction.
　一方、フリー磁性層１０の磁化方向は固定されておらず外部磁界Ｈによって磁化変動する。 On the other hand, the magnetization direction of the free magnetic layer 10 is not fixed and fluctuates due to the external magnetic field H.
　本実施形態では、素子部１２を構成するフリー磁性層１０と非磁性層９との間の界面は、磁石２１の着磁面２１ａと平行な面方向（Ｘ－Ｙ面方向）を向いている。 In the present embodiment, the interface between the free magnetic layer 10 and the nonmagnetic layer 9 constituting the element portion 12 faces the plane direction (XY plane direction) parallel to the magnetized surface 21a of the magnet 21. .
　上記の構成では非磁性層９がＣｕで形成された巨大磁気抵抗効果素子（ＧＭＲ素子）の構成であるが、例えば非磁性層９がＡｌ2Ｏ3、ＭｇＯ等の絶縁材料で形成されるとき、トンネル型磁気抵抗効果素子（ＴＭＲ素子）として構成される。磁気抵抗効果素子２４ａ～２４ｈは異方性磁気抵抗効果素子（ＡＭＲ素子）であってもよい。 The above configuration is a configuration of a giant magnetoresistive effect element (GMR element) in which the nonmagnetic layer 9 is formed of Cu. For example, when the nonmagnetic layer 9 is formed of an insulating material such as Al 2 O 3 or MgO. And configured as a tunnel type magnetoresistive effect element (TMR element). The magnetoresistive elements 24a to 24h may be anisotropic magnetoresistive elements (AMR elements).
　図３に示すように各素子部１２の固定磁性層８の固定磁化方向（Ｐ方向）は、相対移動方向（Ｘ１方向）である。固定磁性層８の固定磁化方向（Ｐ方向）はＸ２方向でもよい。 As shown in FIG. 3, the fixed magnetization direction (P direction) of the fixed magnetic layer 8 of each element unit 12 is the relative movement direction (X1 direction). The fixed magnetization direction (P direction) of the fixed magnetic layer 8 may be the X2 direction.
　次に以下では、磁気抵抗効果素子２４ａを第４の磁気抵抗効果素子２４ａ、磁気抵抗効果素子２４ｂを第６の磁気抵抗効果素子２４ｂ、磁気抵抗効果素子２４ｃを第３の磁気抵抗効果素子２４ｃ、磁気抵抗効果素子２４ｄを第５の磁気抵抗効果素子２４ｄ、磁気抵抗効果素子２４ｅを第１の磁気抵抗効果素子２４ｅ、磁気抵抗効果素子２４ｆを第７の磁気抵抗効果素子２４ｆ、磁気抵抗効果素子２４ｇを第２の磁気抵抗効果素子２４ｇ、磁気抵抗効果素子２４ｈを第８の磁気抵抗効果素子２４ｈと称することとする。 Next, in the following, the magnetoresistive effect element 24a is the fourth magnetoresistive effect element 24a, the magnetoresistive effect element 24b is the sixth magnetoresistive effect element 24b, the magnetoresistive effect element 24c is the third magnetoresistive effect element 24c, The magnetoresistive effect element 24d is the fifth magnetoresistive effect element 24d, the magnetoresistive effect element 24e is the first magnetoresistive effect element 24e, the magnetoresistive effect element 24f is the seventh magnetoresistive effect element 24f, and the magnetoresistive effect element 24g. Are referred to as a second magnetoresistive element 24g, and the magnetoresistive element 24h is referred to as an eighth magnetoresistive element 24h.
　図８に示すように、第１の磁気抵抗効果素子２４ｅ、第２の磁気抵抗効果素子２４ｇ、第３の磁気抵抗効果素子２４ｃ及び第４の磁気抵抗効果素子２４ａによりＡ相のブリッジ回路が構成されている。第１の磁気抵抗効果素子２４ｅと第２の磁気抵抗効果素子２４ｇとがＡ相第１出力端子（Ｖａ１）５０を介して直列接続されている。また、第３の磁気抵抗効果素子２４ｃと第４の磁気抵抗効果素子２４ａとがＡ相第２出力端子（Ｖａ２）５１を介して直列接続される。また、第１の磁気抵抗効果素子２４ｅと第３の磁気抵抗効果素子２４ｃとが入力端子５２を介して、及び第２の磁気抵抗効果素子２４ｇと第４の磁気抵抗効果素子２４ａとが夫々、グランド端子６６，６７を介して接続されている。 As shown in FIG. 8, the first magnetoresistive element 24e, the second magnetoresistive element 24g, the third magnetoresistive element 24c, and the fourth magnetoresistive element 24a constitute an A-phase bridge circuit. Has been. The first magnetoresistive element 24 e and the second magnetoresistive element 24 g are connected in series via the A-phase first output terminal (Va1) 50. The third magnetoresistive element 24 c and the fourth magnetoresistive element 24 a are connected in series via the A-phase second output terminal (Va 2) 51. In addition, the first magnetoresistive effect element 24e and the third magnetoresistive effect element 24c are connected via the input terminal 52, and the second magnetoresistive effect element 24g and the fourth magnetoresistive effect element 24a are respectively connected. They are connected via ground terminals 66 and 67.
　図８に示すようにＡ相第１出力端子（Ｖａ１）５０とＡ相第２出力端子（Ｖａ２）５１は、第１の差動増幅器５８の入力部側に接続され、第１の差動増幅器５８から差動出力が得られるようになっている。 As shown in FIG. 8, the A-phase first output terminal (Va1) 50 and the A-phase second output terminal (Va2) 51 are connected to the input section side of the first differential amplifier 58, and the first differential amplifier. A differential output can be obtained from 58.
　また本実施形態ではもう一つＢ相のブリッジ回路が、第５の磁気抵抗効果素子２４ｄ、第６の磁気抵抗効果素子２４ｂ、第７の磁気抵抗効果素子２４ｆ、及び第８の磁気抵抗効果素子２４ｈにより構成されている。第５の磁気抵抗効果素子２４ｄと第６の磁気抵抗効果素子２４ｂとが、Ｂ相第１出力端子（Ｖｂ１）５４を介して直列接続され、第７の磁気抵抗効果素子２４ｆと第８の磁気抵抗効果素子２４ｈがＢ相第２出力端子（Ｖｂ２）５５を介して直列接続されている。また、図８に示すように第５の磁気抵抗効果素子２４ｄと第７の磁気抵抗効果素子２４ｆとが入力端子５２を介して、及び第６の磁気抵抗効果素子２４ｂと第８の磁気抵抗効果素子２４ｈとが、夫々グランド端子６６，６７を介して接続されている。 In this embodiment, another B-phase bridge circuit includes the fifth magnetoresistive element 24d, the sixth magnetoresistive element 24b, the seventh magnetoresistive element 24f, and the eighth magnetoresistive element. 24h. The fifth magnetoresistive effect element 24d and the sixth magnetoresistive effect element 24b are connected in series via the B-phase first output terminal (Vb1) 54, and the seventh magnetoresistive effect element 24f and the eighth magnetoresistive effect element 24b. The resistive effect element 24h is connected in series via the B-phase second output terminal (Vb2) 55. Further, as shown in FIG. 8, the fifth magnetoresistive effect element 24d and the seventh magnetoresistive effect element 24f are connected via the input terminal 52, and the sixth magnetoresistive effect element 24b and the eighth magnetoresistive effect element. The element 24h is connected via ground terminals 66 and 67, respectively.
　図８に示すようにＢ相第１出力端子（Ｖｂ１）５４とＢ相第２出力端子（Ｖｂ２）５５は、第２の差動増幅器６０の入力部側に接続され、第２の差動増幅器６０から差動出力が得られる。 As shown in FIG. 8, the B-phase first output terminal (Vb1) 54 and the B-phase second output terminal (Vb2) 55 are connected to the input section side of the second differential amplifier 60, and the second differential amplifier. A differential output is obtained from 60.
　図１に示すように、図８に示すブリッジ回路にて直列接続される磁気抵抗効果素子どうしの中心間の間隔はλとなっている。 As shown in FIG. 1, the distance between the centers of magnetoresistive elements connected in series by the bridge circuit shown in FIG. 8 is λ.
　磁気センサ２２が磁石２１に対してＸ１方向に相対移動すると、各磁気抵抗効果素子２４ａ～２４ｈには、磁石２１の着磁面２１ａから外部磁界Ｈ１，Ｈ２が進入する。図１に示すように外部磁界Ｈ１と外部磁界Ｈ２の方向は異なり、またちょうど磁気抵抗効果素子が磁極上に位置すると、磁気抵抗効果素子に対して磁場成分は垂直磁場が支配的となり、外部磁場がゼロの状態（無磁場状態）となる。 When the magnetic sensor 22 moves relative to the magnet 21 in the X1 direction, the external magnetic fields H1 and H2 enter the magnetoresistive elements 24a to 24h from the magnetized surface 21a of the magnet 21. As shown in FIG. 1, the directions of the external magnetic field H1 and the external magnetic field H2 are different, and when the magnetoresistive effect element is positioned on the magnetic pole, the perpendicular magnetic field is dominant in the magnetic field component with respect to the magnetoresistive effect element. Becomes zero (no magnetic field).
　ここで代表して、Ａ相のブリッジ回路を構成し直列接続される第１の磁気抵抗効果素子２４ｅと第２の磁気抵抗効果素子２４ｇに対する外部磁界の進入状態について説明する。 As a representative example, a state in which an external magnetic field enters the first magnetoresistive effect element 24e and the second magnetoresistive effect element 24g that constitute an A-phase bridge circuit and are connected in series will be described.
　第１の磁気抵抗効果素子２４ｅと第２の磁気抵抗効果素子２４ｇは相対移動方向（Ｘ１方向）にλ離れているため、第１の磁気抵抗効果素子２４ｅに外部磁界Ｈ１が進入すると、第２の磁気抵抗効果素子２４ｇには、外部磁界Ｈ２が進入する。このとき固定磁性層８の固定磁化方向（Ｐ方向）はＸ１方向であるから、外部磁界Ｈ１の進入により、第１の磁気抵抗効果素子２４ｅの抵抗値は増大し、一方、外部磁界Ｈ２の進入により、第２の磁気抵抗効果素子２４ｇの抵抗値は減少する。また、磁気センサ２２がＸ１方向にλ／２だけ相対移動すると、第１の磁気抵抗効果素子２４ｅ及び第２の磁気抵抗効果素子２４ｇには垂直磁場が進入するため第１の磁気抵抗効果素子２４ｅ及び第２の磁気抵抗効果素子２４ｇの抵抗値は変化しない。さらに、磁気センサ２２がＸ１方向にλ／２だけ相対移動すると、第１の磁気抵抗効果素子２４ｅには外部磁界Ｈ２が進入し、第２の磁気抵抗効果素子２４ｇには外部磁界Ｈ１が進入するため、第１の磁気抵抗効果素子２４ｅの抵抗値は減少し、第２の磁気抵抗効果素子２４ｇの抵抗値は増大する。 Since the first magnetoresistive element 24e and the second magnetoresistive element 24g are separated from each other by λ in the relative movement direction (X1 direction), when the external magnetic field H1 enters the first magnetoresistive element 24e, the second The external magnetic field H2 enters the magnetoresistive element 24g. At this time, since the fixed magnetization direction (P direction) of the fixed magnetic layer 8 is the X1 direction, the resistance value of the first magnetoresistive effect element 24e increases by the entry of the external magnetic field H1, while the entry of the external magnetic field H2 occurs. As a result, the resistance value of the second magnetoresistive element 24g decreases. When the magnetic sensor 22 is relatively moved in the X1 direction by λ / 2, a vertical magnetic field enters the first magnetoresistive effect element 24e and the second magnetoresistive effect element 24g, and thus the first magnetoresistive effect element 24e. The resistance value of the second magnetoresistive element 24g does not change. Further, when the magnetic sensor 22 is relatively moved in the X1 direction by λ / 2, the external magnetic field H2 enters the first magnetoresistive element 24e, and the external magnetic field H1 enters the second magnetoresistive element 24g. Therefore, the resistance value of the first magnetoresistance effect element 24e decreases and the resistance value of the second magnetoresistance effect element 24g increases.
　図８に示すＡ相のブリッジ回路からは略三角波（あるいは略ｓｉｎ波、略矩形波でもよい）の出力波形が得られる。同じくＢ相のブリッジ回路からも略三角波（あるいは略ｓｉｎ波、略矩形波でもよい）の出力波形が得られるが、位相がλ／２分ずれている。出力波形に基づき、磁気センサ２２あるいは磁石２１の移動速度や移動距離を検出できる。また、Ａ相とＢ相の２系統にすることで、Ａ相のブリッジ回路からの出力波形に対するＢ相のブリッジ回路からの出力波形の位相のずれ方向がどちら方向であるかを検知することで、移動方向を知ることが可能となる。 From the A-phase bridge circuit shown in FIG. 8, an output waveform of a substantially triangular wave (or may be a substantially sin wave or a substantially rectangular wave) is obtained. Similarly, an output waveform of a substantially triangular wave (or a substantially sin wave or a substantially rectangular wave) can be obtained from the B-phase bridge circuit, but the phase is shifted by λ / 2. Based on the output waveform, the moving speed and moving distance of the magnetic sensor 22 or the magnet 21 can be detected. Further, by using two systems of A phase and B phase, it is possible to detect which direction the phase shift direction of the output waveform from the B phase bridge circuit with respect to the output waveform from the A phase bridge circuit is. It becomes possible to know the moving direction.
　磁気抵抗効果素子２４ａ～２４ｈの配置について説明する。図２を用いて説明する。
　Ａ相のブリッジ回路において、直列接続される第１の磁気抵抗効果素子２４ｅと第２の磁気抵抗効果素子２４ｇ、及び第３の磁気抵抗効果素子２４ｃ及び第４の磁気抵抗効果素子２４ａは夫々、相対移動方向（Ｘ１方向）にλの間隔を空けて配置される。 The arrangement of the magnetoresistive effect elements 24a to 24h will be described. This will be described with reference to FIG.
In the A-phase bridge circuit, the first magnetoresistive effect element 24e and the second magnetoresistive effect element 24g, the third magnetoresistive effect element 24c, and the fourth magnetoresistive effect element 24a connected in series are respectively Arranged at an interval of λ in the relative movement direction (X1 direction).
　また、第１の磁気抵抗効果素子２４ｅと第４の磁気抵抗効果素子２４ａ、及び第２の磁気抵抗効果素子２４ｇと第３の磁気抵抗効果素子２４ｃは、縦方向（Ｙ１－Ｙ２方向）に並設されている。 The first magnetoresistive effect element 24e and the fourth magnetoresistive effect element 24a, and the second magnetoresistive effect element 24g and the third magnetoresistive effect element 24c are aligned in the vertical direction (Y1-Y2 direction). It is installed.
　図２の実施形態では、第１の磁気抵抗効果素子２４ｅがＸ２方向のＹ２側に、第２の磁気抵抗効果素子２４ｇがＸ１方向のＹ２側に、第３の磁気抵抗効果素子２４ｃがＸ１方向のＹ１側に、第４の磁気抵抗効果素子２４ａがＸ２方向のＹ１側に夫々配置される。 In the embodiment of FIG. 2, the first magnetoresistance effect element 24e is on the Y2 side in the X2 direction, the second magnetoresistance effect element 24g is on the Y2 side in the X1 direction, and the third magnetoresistance effect element 24c is in the X1 direction. The fourth magnetoresistive effect element 24a is arranged on the Y1 side in the X2 direction on the Y1 side.
　続いて、Ｂ相のブリッジ回路において、直列接続される第５の磁気抵抗効果素子２４ｄと第６の磁気抵抗効果素子２４ｂ、及び第７の磁気抵抗効果素子２４ｆと第８の磁気抵抗効果素子２４ｈは、夫々、相対移動方向（Ｘ１方向）にλの間隔を空けて配置されるとともに、Ａ相のブリッジ回路を構成する各磁気抵抗効果素子に対してλ／２だけ相対移動方向（Ｘ１方向）にずれた位置に配置される。 Subsequently, in the B-phase bridge circuit, the fifth magnetoresistive effect element 24d and the sixth magnetoresistive effect element 24b connected in series, and the seventh magnetoresistive effect element 24f and the eighth magnetoresistive effect element 24h are connected. Are arranged at an interval of λ in the relative movement direction (X1 direction), and relative movement direction (X1 direction) by λ / 2 with respect to each magnetoresistive element constituting the A-phase bridge circuit. It is arranged at a position shifted to.
　また、第５の磁気抵抗効果素子２４ｄと第８の磁気抵抗効果素子２４ｈ、及び第６の磁気抵抗効果素子２４ｂと第７の磁気抵抗効果素子２４ｆは、縦方向（Ｙ１－Ｙ２方向）に並設されている。 In addition, the fifth magnetoresistive effect element 24d and the eighth magnetoresistive effect element 24h, and the sixth magnetoresistive effect element 24b and the seventh magnetoresistive effect element 24f are arranged in the vertical direction (Y1-Y2 direction). It is installed.
　図２の実施形態では、第５の磁気抵抗効果素子２４ｄが第３の磁気抵抗効果素子２４ｃよりもＸ１側に、第６の磁気抵抗効果素子２４ｂが、第３の磁気抵抗効果素子２４ｃと第４の磁気抵抗効果素子２４ａの間に、第７の磁気抵抗効果素子２４ｆが第１の磁気抵抗効果素子２４ｅと第２の磁気抵抗効果素子２４ｇの間に、第８の磁気抵抗効果素子２４ｈが第２の磁気抵抗効果素子２４ｇよりもＸ１側に夫々、配置される。 In the embodiment of FIG. 2, the fifth magnetoresistive element 24d is closer to the X1 side than the third magnetoresistive element 24c, and the sixth magnetoresistive element 24b is connected to the third magnetoresistive element 24c and the third magnetoresistive element 24c. Between the first magnetoresistive effect element 24e and the second magnetoresistive effect element 24g, and between the first magnetoresistive effect element 24g and the eighth magnetoresistive effect element 24h. The second magnetoresistive effect element 24g is disposed on the X1 side.
　次に、入力端子５２とグランド端子６６，６７の配置、並びに、入力端子５２及びグラ
ンド端子６６，６７と磁気抵抗効果素子間を電気的に接続する配線層について説明する。図２及び図４を用いて説明する。 Next, the arrangement of the input terminal 52 and the ground terminals 66 and 67 and the wiring layer for electrically connecting the input terminal 52 and the ground terminals 66 and 67 and the magnetoresistive element will be described. This will be described with reference to FIGS.
　以下では、「磁気抵抗効果素子形成領域」、「第１の領域」、「第２の領域」、「第３の領域」という用語を使用する。 Hereinafter, the terms “magnetoresistive element formation region”, “first region”, “second region”, and “third region” are used.
　「磁気抵抗効果素子形成領域」は、全ての磁気抵抗効果素子２４ａ～２４ｈが含まれる領域であり、各磁気抵抗効果素子の外側縁部（隣り合う磁気抵抗効果素子との間で対向しない縁部）を直線で結んだ図２の点線の領域７５を指す。 The “magnetoresistive element forming region” is a region including all the magnetoresistive effect elements 24a to 24h, and is an outer edge portion of each magnetoresistive effect element (an edge portion that is not opposed to an adjacent magnetoresistive effect element). ) Is connected by a straight line.
　また「第１の領域」、「第２の領域」、「第３の領域」とは、相対移動方向（図示Ｘ１方向）に間隔を空けて並設された各磁気抵抗効果素子間の領域を指し、Ａ相のブリッジ回路を構成する各磁気抵抗効果素子に対するＢ相のブリッジ回路を構成する各磁気抵抗効果素子のずれ方向（この実施形態では、磁気センサの相対移動方向と同じ図示Ｘ１方向である）に向けて第１の領域７０、第２の領域７１、第３の領域７２の順に並設されている。すなわち第１の領域７０は、第１の磁気抵抗効果素子２４ｅ、第４の磁気抵抗効果素子２４ａ、第６の磁気抵抗効果素子２４ｂ及び第７の磁気抵抗効果素子２４ｆで囲まれた領域を指す。また第２の領域７１は、第２の磁気抵抗効果素子２４ｇ、第３の磁気抵抗効果素子２４ｃ、第６の磁気抵抗効果素子２４ｂ、第７の磁気抵抗効果素子２４で囲まれた領域を指す。さらに第３の領域７２は、第２の磁気抵抗効果素子２４ｇ、第３の磁気抵抗効果素子２４ｃ、第５の磁気抵抗効果素子２４ｄ及び第８の磁気抵抗効果素子２４ｈで囲まれた領域を指す。 The “first region”, “second region”, and “third region” are regions between the magnetoresistive effect elements arranged in parallel with a gap in the relative movement direction (X1 direction in the drawing). The displacement direction of each magnetoresistive effect element constituting the B phase bridge circuit with respect to each magnetoresistive effect element constituting the A phase bridge circuit (in this embodiment, in the X1 direction shown in the figure, which is the same as the relative movement direction of the magnetic sensor) The first region 70, the second region 71, and the third region 72 are arranged in this order. That is, the first region 70 indicates a region surrounded by the first magnetoresistance effect element 24e, the fourth magnetoresistance effect element 24a, the sixth magnetoresistance effect element 24b, and the seventh magnetoresistance effect element 24f. . The second region 71 is a region surrounded by the second magnetoresistive element 24g, the third magnetoresistive element 24c, the sixth magnetoresistive element 24b, and the seventh magnetoresistive element 24. . Furthermore, the third region 72 indicates a region surrounded by the second magnetoresistive effect element 24g, the third magnetoresistive effect element 24c, the fifth magnetoresistive effect element 24d, and the eighth magnetoresistive effect element 24h. .
　図２，図４に示すように入力端子５２は、第２の領域７１内にあり、磁気抵抗効果素子形成領域７５の横方向（Ｘ１－Ｘ２方向）及び縦方向（Ｙ１－Ｙ２方向）の略中央位置に形成される。ここで「略中央位置」とは、中央位置から０～２０μｍ程度のずれ量を含むと定義される。なお中央位置には製造誤差も含まれる。 As shown in FIGS. 2 and 4, the input terminal 52 is in the second region 71, and is substantially the horizontal direction (X1-X2 direction) and the vertical direction (Y1-Y2 direction) of the magnetoresistive effect element formation region 75. It is formed at the center position. Here, the “substantially central position” is defined as including a deviation amount of about 0 to 20 μm from the central position. The center position includes manufacturing errors.
　入力端子５２は１個だけ設けられ、Ａ相のブリッジ回路及びＢ相のブリッジ回路の共通端子として機能している。 Only one input terminal 52 is provided and functions as a common terminal for the A-phase bridge circuit and the B-phase bridge circuit.
　一方、グランド端子６６，６７は２個設けられる。グランド端子６６は第３の領域７２に、グランド端子６７は第１の領域７０に設けられる。グランド端子６６は第３の領域７２の横方向（Ｘ１－Ｘ２方向）の略中央位置に形成され、また入力端子５２から見てＹ２側に形成される。一方、グランド端子６７は第１の領域７０の横方向（Ｘ１－Ｘ２方向）の略中央位置に形成され、また入力端子５２から見てＹ１側に形成される。グランド端子６６，６７は入力端子５２を中心として略点対称の位置に形成されている。「略点対称の位置」とは、点対称位置から０～２０μｍ程度のずれ量を含むと定義される。グランド端子６６には、Ａ相のブリッジ回路を構成する第２の磁気抵抗効果素子２４ｇと、Ｂ相のブリッジ回路を構成する第８の磁気抵抗効果素子２４ｈとが電気的に接続されている。一方、グランド端子６７には、Ａ相のブリッジ回路を構成する第４の磁気抵抗効果素子２４ａと、Ｂ相のブリッジ回路を構成する第６の磁気抵抗効果素子２４ｂとが電気的に接続される。 On the other hand, two ground terminals 66 and 67 are provided. The ground terminal 66 is provided in the third region 72, and the ground terminal 67 is provided in the first region 70. The ground terminal 66 is formed at a substantially central position in the lateral direction (X1-X2 direction) of the third region 72, and is formed on the Y2 side when viewed from the input terminal 52. On the other hand, the ground terminal 67 is formed at a substantially central position in the lateral direction (X1-X2 direction) of the first region 70, and is formed on the Y1 side when viewed from the input terminal 52. The ground terminals 66 and 67 are formed at substantially point-symmetrical positions with the input terminal 52 as the center. The “substantially point symmetric position” is defined as including a deviation amount of about 0 to 20 μm from the point symmetric position. The ground terminal 66 is electrically connected to the second magnetoresistive element 24g constituting the A-phase bridge circuit and the eighth magnetoresistive element 24h constituting the B-phase bridge circuit. On the other hand, the fourth magnetoresistive element 24a constituting the A-phase bridge circuit and the sixth magnetoresistive element 24b constituting the B-phase bridge circuit are electrically connected to the ground terminal 67. .
　図４に示すように入力端子５２から図示左右方向に入力配線層７７，７８が延出して形成されている。入力配線層７７は図示左方向（Ｘ２方向）に直線で延び、途中で分岐してＡ相のブリッジ回路を構成する第１の磁気抵抗効果素子２４ｅとＢ相のブリッジ回路を構成する第７の磁気抵抗効果素子２４ｆとに接続されている。一方、入力配線層７８は、図示右方向（Ｘ１方向）に直線で延び、途中で分岐してＡ相のブリッジ回路を構成する第３の磁気抵抗効果素子２４ｃとＢ相のブリッジ回路を構成する第５の磁気抵抗効果素子２４ｄとに接続されている。 As shown in FIG. 4, input wiring layers 77 and 78 are formed to extend from the input terminal 52 in the horizontal direction in the figure. The input wiring layer 77 extends in a straight line in the left direction (X2 direction) in the figure, and branches in the middle to form a first magnetoresistive effect element 24e constituting an A phase bridge circuit and a seventh phase constituting a B phase bridge circuit. It is connected to the magnetoresistive effect element 24f. On the other hand, the input wiring layer 78 linearly extends in the right direction (X1 direction) in the drawing, and branches in the middle to constitute the B-phase bridge circuit with the third magnetoresistive effect element 24c constituting the A-phase bridge circuit. It is connected to the fifth magnetoresistive element 24d.
　一方、図４に示すように、グランド端子６６からグランド配線層７９が延出して形成されており、第２の磁気抵抗効果素子２４ｇ及び第８の磁気抵抗効果素子２４ｈと電気的に接続される。またグランド端子６７からグランド配線層８０が延出して形成されており、第４の磁気抵抗効果素子２４ａ及び第６の磁気抵抗効果素子２４ｂと電気的に接続されている。この実施形態では、グランド配線層７９，８０の引き回し形状は略矩形波の形状である。 On the other hand, as shown in FIG. 4, a ground wiring layer 79 extends from the ground terminal 66 and is electrically connected to the second magnetoresistive element 24g and the eighth magnetoresistive element 24h. . A ground wiring layer 80 extends from the ground terminal 67 and is electrically connected to the fourth magnetoresistive element 24a and the sixth magnetoresistive element 24b. In this embodiment, the routing shape of the ground wiring layers 79 and 80 is a substantially rectangular wave shape.
　次に、出力端子５０，５１，５４，５５の配置、並びに、出力端子５０，５１，５４，５５と磁気抵抗効果素子間を電気的に接続する配線層について説明する。図２及び図５を用いて説明する。 Next, the arrangement of the output terminals 50, 51, 54, and 55 and the wiring layer that electrically connects the output terminals 50, 51, 54, and 55 to the magnetoresistive effect element will be described. This will be described with reference to FIGS.
　図２，図５に示すように、Ａ相第１出力端子（Ｖａ１）５０及びＡ相第２出力端子（Ｖａ２）５１は共に、第１の領域７０に形成される。Ａ相第１出力端子（Ｖａ１）５０とＡ相第２出力端子（Ｖａ２）５１は第１の領域７０の横方向（Ｘ１－Ｘ２方向）の略中央位置に形成される。またＢ相第１出力端子（Ｖｂ１）５４及びＢ相第２出力端子（Ｖｂ２）は共に、第３の領域７２に形成される。Ｂ相第１出力端子（Ｖｂ１）５４及びＢ相第２出力端子（Ｖｂ２）は第３の領域７２の横方向（Ｘ１－Ｘ２方向）の略中央位置に形成される。 2 and 5, both the A-phase first output terminal (Va1) 50 and the A-phase second output terminal (Va2) 51 are formed in the first region 70. The A-phase first output terminal (Va1) 50 and the A-phase second output terminal (Va2) 51 are formed at a substantially central position in the lateral direction (X1-X2 direction) of the first region 70. The B-phase first output terminal (Vb1) 54 and the B-phase second output terminal (Vb2) are both formed in the third region 72. The B-phase first output terminal (Vb1) 54 and the B-phase second output terminal (Vb2) are formed at a substantially central position in the horizontal direction (X1-X2 direction) of the third region 72.
　図５に示すように、Ａ相第１出力端子（Ｖａ１）５０から第１の出力配線層８１が延出して形成されており、Ａ相のブリッジ回路を構成する第１の磁気抵抗効果素子２４ｅ及び第２の磁気抵抗効果素子２４ｇと電気的に接続されている。またＡ相第２出力端子（Ｖａ２）５１から第２の出力配線層８２が延出して形成されており、Ａ相のブリッジ回路を構成する第３の磁気抵抗効果素子２４ｃ及び第４の磁気抵抗効果素子２４ａと電気的に接続されている。 As shown in FIG. 5, a first output wiring layer 81 is formed to extend from the A-phase first output terminal (Va1) 50, and the first magnetoresistive effect element 24e constituting the A-phase bridge circuit is formed. And the second magnetoresistance effect element 24g. A second output wiring layer 82 is formed to extend from the A-phase second output terminal (Va2) 51, and the third magnetoresistive element 24c and the fourth magnetoresistive element constituting the A-phase bridge circuit. It is electrically connected to the effect element 24a.
　また、Ｂ相第１出力端子（Ｖｂ１）５４から第３の出力配線層８３が延出して形成されており、Ｂ相のブリッジ回路を構成する第５の磁気抵抗効果素子２４ｄ及び第６の磁気抵抗効果素子２４ｂと電気的に接続されている。またＢ相第２出力端子（Ｖｂ２）５５から第４の出力配線層８４が延出して形成されており、Ｂ相のブリッジ回路を構成する第７の磁気抵抗効果素子２４ｆ及び第８の磁気抵抗効果素子２４ｈと電気的に接続されている。 The third output wiring layer 83 is formed to extend from the B-phase first output terminal (Vb1) 54, and the fifth magnetoresistive effect element 24d and the sixth magnetism constituting the B-phase bridge circuit are formed. It is electrically connected to the resistance effect element 24b. The fourth output wiring layer 84 is formed to extend from the B-phase second output terminal (Vb2) 55, and the seventh magnetoresistive element 24f and the eighth magnetoresistive constituting the B-phase bridge circuit. It is electrically connected to the effect element 24h.
　上記した各配線層７７～８４は基板２３の表面２３ａに図示しない絶縁層を介して平面的に形成されている。すなわち配線層同士が絶縁層を介して積層形成された構成ではない。なお配線層７７～８４の形成面が、磁気抵抗効果素子２４ａ～２４ｈの形成面と異なっていてもよい。配線層７７～８４はＡｌ等の良導体で形成される。 Each of the wiring layers 77 to 84 described above is formed in a plane on the surface 23a of the substrate 23 via an insulating layer (not shown). In other words, the wiring layers are not laminated with an insulating layer interposed therebetween. The formation surfaces of the wiring layers 77 to 84 may be different from the formation surfaces of the magnetoresistive elements 24a to 24h. The wiring layers 77 to 84 are made of a good conductor such as Al.
　本実施形態の磁気センサ２２の特徴的部分は以下の通りである。
（１）　磁気センサ２２には、Ａ相のブリッジ回路とＢ相のブリッジ回路を構成する複数の磁気抵抗効果素子２４ａ～２４ｈを備える（図１、図８参照）。 Characteristic portions of the magnetic sensor 22 of the present embodiment are as follows.
(1) The magnetic sensor 22 includes a plurality of magnetoresistance effect elements 24a to 24h constituting an A-phase bridge circuit and a B-phase bridge circuit (see FIGS. 1 and 8).
（２）　入力端子５２、グランド端子６６，６７及び出力端子５０，５１，５４，５５は、相対移動方向（Ｘ１方向）に間隔を空けて並設された各磁気抵抗効果素子２４ａ～２４ｈの間の領域（第１の領域７０，第２の領域７１，第３の領域７２）に形成される（図２、図４、図５参照）。 (2) The input terminal 52, the ground terminals 66 and 67, and the output terminals 50, 51, 54, and 55 are arranged between the magnetoresistive elements 24a to 24h arranged in parallel with a gap in the relative movement direction (X1 direction). (Refer to FIG. 2, FIG. 4, FIG. 5) of the first region 70, the second region 71, and the third region 72.
（３）　入力端子５２が１個だけ設けられ、グランド端子６６，６７が２個設けられる（図２、図４、図８参照）。 (3) Only one input terminal 52 is provided, and two ground terminals 66 and 67 are provided (see FIGS. 2, 4, and 8).
　上記（２）により、従来に比べて、磁気センサ２２の縦寸法Ｗ３を効果的に小さくできる。また上記（３）により、配線層の引き回しの自由度を向上できる。すなわち本実施形態と違って入力端子５２と同様にグランド端子も１個であると、１個のグランド端子に、第２の磁気抵抗効果素子２４ｇ、第４の磁気抵抗効果素子２４ａ、第６の磁気抵抗効果素子２４ｂ及び第８の磁気抵抗効果素子２４ｈの全てを接続しないといけないため、配線層の引き回しの自由度が低下し、また各磁気抵抗効果素子とグランド端子間の配線層の長さ寸法のばらつきが非常に大きくなる。本実施形態では上記従来の問題を解消でき、配線層の引き回しの自由度を向上でき、各端子と各磁気抵抗効果素子間の配線層の長さのばらつきを従来よりも小さくできる。よって各出力端子５０、５１、５４、５５から中点電位を得るべく従来のように極端に配線層の幅寸法を変える必要もなく、図２、図４、図５に示すように、各配線層をほぼ磁気抵抗効果素子形成領域７５内に収めることが出来る。以上により磁気センサ２２の横寸法Ｌ３及び縦寸法Ｗ３を従来よりも小さくでき磁気センサ２２の小型化を促進できる。したがって磁気エンコーダ２０の小型化を促進でき、また磁石２１の縦寸法を小さくできるため、製造コストの低減を図ることが可能である。 According to the above (2), the vertical dimension W3 of the magnetic sensor 22 can be effectively reduced as compared with the conventional case. In addition, the degree of freedom in routing the wiring layer can be improved by the above (3). That is, unlike the present embodiment, when the number of ground terminals is one as with the input terminal 52, the second magnetoresistive effect element 24g, the fourth magnetoresistive effect element 24a, and the sixth Since all of the magnetoresistive effect element 24b and the eighth magnetoresistive effect element 24h must be connected, the degree of freedom of routing of the wiring layer is reduced, and the length of the wiring layer between each magnetoresistive effect element and the ground terminal The dimensional variation becomes very large. In the present embodiment, the above-described conventional problems can be solved, the degree of freedom of routing of the wiring layer can be improved, and the variation in the length of the wiring layer between each terminal and each magnetoresistive effect element can be made smaller than before. Therefore, it is not necessary to change the width dimension of the wiring layer extremely as in the prior art in order to obtain the midpoint potential from each output terminal 50, 51, 54, 55, and as shown in FIG. 2, FIG. 4, and FIG. The layer can be accommodated almost in the magnetoresistive element formation region 75. As described above, the horizontal dimension L3 and the vertical dimension W3 of the magnetic sensor 22 can be made smaller than before, and the miniaturization of the magnetic sensor 22 can be promoted. Therefore, it is possible to promote downsizing of the magnetic encoder 20 and to reduce the vertical dimension of the magnet 21, thereby reducing the manufacturing cost.
　本実施形態では、磁気センサ２２の横寸法Ｌ３を６００～４０００μｍの範囲内にでき、磁気センサ２２の縦寸法Ｗ３を５００～１０００μｍの範囲内にできる。 In this embodiment, the horizontal dimension L3 of the magnetic sensor 22 can be in the range of 600 to 4000 μm, and the vertical dimension W3 of the magnetic sensor 22 can be in the range of 500 to 1000 μm.
　例えば磁気抵抗効果素子２４ａ～２４ｈの各基準抵抗値（外部磁界が作用していないときの抵抗値）を調整して中点電位を得る手法もあるが、磁気抵抗効果素子２４ａ～２４ｈの磁気感度が夫々異なってしまうため、各磁気抵抗効果素子２４ａ～２４ｈの各基準抵抗値は同じとなるように調整する。本実施形態では、その上で、磁気抵抗効果素子２４ａ～２４ｈに電気的に接続される各端子の配置を改良することで、出力特性を劣化させることなく、従来に比べて磁気センサ２２及び磁気エンコーダ２０の小型化を実現することが出来る。 For example, there is a method of obtaining the midpoint potential by adjusting the respective reference resistance values (resistance values when no external magnetic field is applied) of the magnetoresistive effect elements 24a to 24h, but the magnetic sensitivity of the magnetoresistive effect elements 24a to 24h. Therefore, the reference resistance values of the magnetoresistive elements 24a to 24h are adjusted to be the same. In this embodiment, the arrangement of the terminals electrically connected to the magnetoresistive effect elements 24a to 24h is further improved, and the magnetic sensor 22 and the magnetism are compared with the conventional one without deteriorating the output characteristics. Miniaturization of the encoder 20 can be realized.
　上記（３）については、グランド端子が１個で、入力端子が２個でもよい。ただし、グランド端子は接地すればよいだけなので、入力端子５２を１個としグランド端子６６，６７を２個としたほうが、外部回路に設けられたパッドとの電気的接続を簡単に行いやすく好適である。 For (3) above, there may be one ground terminal and two input terminals. However, since the ground terminal only needs to be grounded, it is preferable to use one input terminal 52 and two ground terminals 66 and 67 because it is easy to make electrical connection with pads provided in an external circuit. is there.
　以下、好ましい本実施形態の特徴的部分を説明する。
（４）　入力端子５２は磁気抵抗効果素子形成領域７５の略中央位置（第２の領域７１）に形成される中心端子である。またグランド端子６６，６７は、夫々、第１の領域７０と第３の領域７２に形成され、入力端子５２を中心として略点対称の位置に形成される。入力端子５２はＡ相のブリッジ回路及びＢ相のブリッジ回路の共通端子である。一方、２個設けられたグランド端子６６，６７のうち、一方のグランド端子６６は、Ａ相のブリッジ回路を構成する一方の直列回路、及びＢ相のブリッジ回路を構成する一方の直列回路の共通端子であり、他方のグランド端子６７は、Ａ相のブリッジ回路を構成する他方の直列回路、及びＢ相のブリッジ回路を構成する他方の直列回路の共通端子である（図２，図４，図８参照）。 Hereinafter, the characteristic part of this preferred embodiment will be described.
(4) The input terminal 52 is a central terminal formed at a substantially central position (second region 71) of the magnetoresistive effect element forming region 75. The ground terminals 66 and 67 are formed in the first region 70 and the third region 72, respectively, and are formed at substantially point-symmetrical positions around the input terminal 52. The input terminal 52 is a common terminal for the A-phase bridge circuit and the B-phase bridge circuit. On the other hand, of the two ground terminals 66 and 67, one ground terminal 66 is common to one series circuit constituting the A-phase bridge circuit and one series circuit constituting the B-phase bridge circuit. The other ground terminal 67 is a common terminal of the other series circuit constituting the A-phase bridge circuit and the other series circuit constituting the B-phase bridge circuit (FIGS. 2, 4 and 4). 8).
　図４に示すように、入力端子５２を磁気抵抗効果素子形成領域７５の略中央位置に設けたため、入力端子５２から第１の磁気抵抗効果素子２４ｅ、第３の磁気抵抗効果素子２４ｃ、第５の磁気抵抗効果素子２４ｄ及び第７の磁気抵抗効果素子２４ｆまでの入力配線層７７，７８の長さ寸法がほぼ同じになるように調整しやすい。また、図４に示すように、グランド端子６６，６７を第１の領域７０と第３の領域７２に夫々設け、しかも各グランド端子６６，６７に近い位置にありグランド端子に接続が必要なＡ相側の磁気抵抗効果素子と、Ｂ相側の磁気抵抗効果素子とを、夫々のグランド端子６６，６７にグランド配線層７９，８０を介して電気的に接続している。よって、グランド端子６６，６７から各磁気抵抗効果素子までのグランド配線層７９，８０の長さ寸法がほぼ同じになるように調整しやすい。 As shown in FIG. 4, since the input terminal 52 is provided at a substantially central position of the magnetoresistive effect element forming region 75, the first magnetoresistive effect element 24e, the third magnetoresistive effect element 24c, the fifth The input wiring layers 77 and 78 up to the magnetoresistive effect element 24d and the seventh magnetoresistive effect element 24f can be easily adjusted so that the lengths thereof are substantially the same. Further, as shown in FIG. 4, the ground terminals 66 and 67 are provided in the first region 70 and the third region 72, respectively, and are close to the ground terminals 66 and 67 and need to be connected to the ground terminals. The phase-side magnetoresistive effect element and the B-phase side magnetoresistive effect element are electrically connected to the ground terminals 66 and 67 via the ground wiring layers 79 and 80, respectively. Therefore, the lengths of the ground wiring layers 79 and 80 from the ground terminals 66 and 67 to the magnetoresistive elements can be easily adjusted so as to be substantially the same.
（５）Ｂ相のブリッジ回路を構成する第５の磁気抵抗効果素子２４ｄ、第６の磁気抵抗効果素子２４ｂ、第７の磁気抵抗効果素子２４ｆ及び第８の磁気抵抗効果素子２４ｈは、Ａ相を構成する各磁気抵抗効果素子に対してＸ１方向に向けてλ／２だけずれて配置される（図１，図２参照）。このずれ方向（Ｘ１方向）に向けて、各磁気抵抗効果素子の間の相対移動方向における領域を、第１の領域７０、第２の領域７１、第３の領域７２と定めたとき、Ａ相第１出力端子（Ｖａ１）５０及びＡ相第２出力端子（Ｖａ２）５１は第１の領域７０に設けられ、Ｂ相第１出力端子（Ｖｂ１）５４及びＢ相第２出力端子（Ｖｂ２）５５は夫々、第３の領域７２に設けられる（図５参照）。 (5) The fifth magnetoresistive effect element 24d, the sixth magnetoresistive effect element 24b, the seventh magnetoresistive effect element 24f, and the eighth magnetoresistive effect element 24h constituting the B-phase bridge circuit are the A phase Are displaced by λ / 2 in the X1 direction (see FIGS. 1 and 2). When the regions in the relative movement direction between the magnetoresistive elements are defined as the first region 70, the second region 71, and the third region 72 in the direction of displacement (X1 direction), the A phase The first output terminal (Va1) 50 and the A-phase second output terminal (Va2) 51 are provided in the first region 70, and the B-phase first output terminal (Vb1) 54 and the B-phase second output terminal (Vb2) 55 are provided. Are provided in the third region 72 (see FIG. 5).
（６）Ａ相第１出力端子（Ｖａ１）５０とＢ相第１出力端子（Ｖｂ１）５４、及びＡ相第２出力端子（Ｖａ２）５１とＢ相第２出力端子（Ｖｂ２）５５とが入力端子５２を中心として、略点対称の位置に配置されている（図５参照）。 (6) A-phase first output terminal (Va1) 50 and B-phase first output terminal (Vb1) 54, and A-phase second output terminal (Va2) 51 and B-phase second output terminal (Vb2) 55 are input. The terminal 52 is arranged at a substantially point-symmetrical position (see FIG. 5).
　図４に示す入力端子５２やグランド端子６６、６７の配置より劣るものの、上記（５）（６）により、各出力端子と各磁気抵抗効果素子との間の出力配線層８１～８４の長さ寸法のばらつきが小さくなるように調整しやすい。 Although inferior to the arrangement of the input terminal 52 and the ground terminals 66 and 67 shown in FIG. 4, the lengths of the output wiring layers 81 to 84 between the output terminals and the magnetoresistive effect elements according to the above (5) and (6). Easy to adjust so that dimensional variation is small.
　なお図５では、Ａ相第１出力端子５０及びＡ相第２出力端子５１が共に第１の領域７０の横方向の略中央位置に設けられるが、配線層の長さのばらつきをより小さくするには、図６に示すように、Ａ相第１出力端子５０及びＡ相第２出力端子５１を、第１の領域７０の横方向の略中央位置からＸ１寄りに形成したほうがよい。同様に、Ｂ相第１出力端子５４及びＢ相第２出力端子５５を、第３の領域７２の横方向の略中央位置からＸ２寄りに形成したほうがよい。 In FIG. 5, both the A-phase first output terminal 50 and the A-phase second output terminal 51 are provided at the substantially central position in the lateral direction of the first region 70, but the variation in the length of the wiring layer is further reduced. As shown in FIG. 6, it is better to form the A-phase first output terminal 50 and the A-phase second output terminal 51 closer to X1 from the substantially central position in the lateral direction of the first region 70. Similarly, the B-phase first output terminal 54 and the B-phase second output terminal 55 are preferably formed closer to X2 from the substantially central position in the lateral direction of the third region 72.
　また図２では、グランド端子、出力端子を第１の領域７０及び第３の領域７２の夫々において縦方向（Ｙ１－Ｙ２方向）に一列に配列していたが、図６のように各端子を横方向（Ｘ１－Ｘ２方向）に少しずつずらして配置すると、外部回路のパッドが磁気センサ２２から見て例えば図示Ｙ２側にのみ設けられている場合、磁気センサ２２側のグランド端子及び出力端子と外部回路側のパッド間をワイヤボンディングしやすいといった効果もある。 In FIG. 2, the ground terminals and the output terminals are arranged in a row in the vertical direction (Y1-Y2 direction) in each of the first region 70 and the third region 72. However, as shown in FIG. If the external circuit pads are provided only on the Y2 side as viewed from the magnetic sensor 22, for example, when the magnetic circuit 22 is disposed slightly shifted in the lateral direction (X1-X2 direction), the ground terminal and the output terminal on the magnetic sensor 22 side There is also an effect that it is easy to wire bond between pads on the external circuit side.
　また本実施形態では、図４，図５に示す各端子の配置と配線層の引き回しの構成とすることで、入力端子５２と各磁気抵抗効果素子間の入力配線層７７，７８の長さ寸法、グランド端子６６，６７と各磁気抵抗効果素子間のグランド配線層７９，８０の長さ寸法、及び出力端子と各磁気抵抗効果素子間の出力配線層８１～８４の長さ寸法のばらつきを概ねλ／２未満にでき、従来に比べて飛躍的に、各磁気抵抗効果素子と各端子間の配線層の長さ寸法のばらつきを小さくできる。したがって図２、図４及び図５に示すように、極端に配線層の幅寸法を広げる箇所を設けなくてもよくなり、磁気センサ２２の更なる小型化を促進することが可能になる。 Further, in the present embodiment, the length dimensions of the input wiring layers 77 and 78 between the input terminal 52 and each of the magnetoresistive effect elements are obtained by adopting the arrangement of the terminals and the wiring layer routing shown in FIGS. The variations in the length dimension of the ground wiring layers 79 and 80 between the ground terminals 66 and 67 and the magnetoresistive effect elements, and the length dimension of the output wiring layers 81 to 84 between the output terminal and the magnetoresistive effect elements are approximately. It can be less than λ / 2, and the variation in the length dimension of the wiring layer between each magnetoresistive effect element and each terminal can be dramatically reduced as compared with the prior art. Therefore, as shown in FIGS. 2, 4, and 5, it is not necessary to provide a portion where the width dimension of the wiring layer is extremely increased, and further miniaturization of the magnetic sensor 22 can be promoted.
（７）縦方向（Ｙ１－Ｙ２方向）に並設された各磁気抵抗効果素子の間には２本以下の配線層が配置される（図２参照）。本実施形態の各端子の配置と各配線層の引き回しの構成によれば、縦方向（Ｙ１－Ｙ２方向）に並設された各磁気抵抗効果素子の間に２本以下の配線層を配置するだけでよく成り、その結果、磁気センサ２２の縦寸法Ｗ３をより小さくでき、磁気センサ２２の更なる小型化を促進できる。 (7) Two or less wiring layers are arranged between the magnetoresistive elements arranged in parallel in the vertical direction (Y1-Y2 direction) (see FIG. 2). According to the arrangement of the terminals and the routing of the wiring layers in the present embodiment, two or less wiring layers are arranged between the magnetoresistive elements arranged in parallel in the vertical direction (Y1-Y2 direction). As a result, the vertical dimension W3 of the magnetic sensor 22 can be further reduced, and further downsizing of the magnetic sensor 22 can be promoted.
　本実施形態では、磁気抵抗効果素子形成領域７５から配線層や端子が一部はみ出す構成を除外するものでない。実際、図２の実施形態では一部の配線層が磁気抵抗効果素子形成領域７５からはみ出している。しかし、このはみ出し量は従来に比べて十分に小さい。また本実施形態では磁気抵抗効果素子形成領域７５内に配線層及び端子が全て収まるように配置することも可能である。 In the present embodiment, the configuration in which the wiring layer and the terminal partially protrude from the magnetoresistive effect element formation region 75 is not excluded. Actually, in the embodiment of FIG. 2, a part of the wiring layer protrudes from the magnetoresistive element formation region 75. However, the amount of protrusion is sufficiently smaller than that of the prior art. In the present embodiment, it is also possible to arrange the wiring layer and the terminal so as to be all within the magnetoresistive element forming region 75.
　本実施形態の磁気エンコーダ２０は、図１に示すように磁気センサ２２が磁石２１に対して直線的に相対移動するものであったが、図９に示すように、例えば表面８９ａにＮ極とＳ極とが交互に着磁された回転ドラム８９と磁気センサ２２とを有し、回転ドラム８９の回転によって得られた出力により、回転速度や回転数、回転方向を検知できる回転型の磁気エンコーダであってもよい。 In the magnetic encoder 20 of the present embodiment, the magnetic sensor 22 linearly moves relative to the magnet 21 as shown in FIG. 1, but as shown in FIG. A rotary magnetic encoder having a rotating drum 89 and magnetic sensor 22 alternately magnetized with S poles, and capable of detecting the rotation speed, the number of rotations, and the direction of rotation based on the output obtained by the rotation of the rotating drum 89 It may be.
　図９の拡大図に示すように、図１に示す直線移動の磁気エンコーダと同様に、Ｎ極とＳ極の中心間距離（ピッチ）をλとしたとき、直列接続される各磁気抵抗効果素子どうしの中心間距離はλに制御されている。図９では代表して直列接続される第３の磁気抵抗効果素子２４ｃと第４の磁気抵抗効果素子２４ａが図示されている。 As shown in the enlarged view of FIG. 9, each magnetoresistive element connected in series when the distance (pitch) between the centers of the N pole and the S pole is λ, similar to the linearly moving magnetic encoder shown in FIG. The distance between the centers is controlled to λ. FIG. 9 representatively shows a third magnetoresistive element 24c and a fourth magnetoresistive element 24a connected in series.
　図９に示すように、各磁気抵抗効果素子２４ａ～２４ｈの固定磁性層８の固定磁化方向（Ｐ方向）は、磁気センサ２２の基板２３の中心を、磁気センサ２２の相対回転方向上の接点としたときの接線方向（磁気センサ２２の相対移動方向）と平行な方向に固定されている。 As shown in FIG. 9, the fixed magnetization direction (P direction) of the fixed magnetic layer 8 of each of the magnetoresistive effect elements 24 a to 24 h is the contact point on the center of the substrate 23 of the magnetic sensor 22 in the relative rotation direction of the magnetic sensor 22. Is fixed in a direction parallel to the tangential direction (relative movement direction of the magnetic sensor 22).
本実施形態の磁気エンコーダの斜視図、The perspective view of the magnetic encoder of this embodiment, 図１の磁気エンコーダを構成する磁気センサの平面図（配線層を斜線で示した）、1 is a plan view of a magnetic sensor constituting the magnetic encoder of FIG. 磁気センサを構成する磁気抵抗効果素子の拡大平面図、An enlarged plan view of a magnetoresistive effect element constituting a magnetic sensor, 図２に示す磁気センサの構成部材の一部を抜粋して示した平面図、FIG. 3 is a plan view showing an excerpt of some of the constituent members of the magnetic sensor shown in FIG. 図２に示す磁気センサの構成部材の一部を抜粋して示した平面図、FIG. 3 is a plan view showing an excerpt of some of the constituent members of the magnetic sensor shown in FIG. 図２とは異なる端子配置を説明するための磁気センサの部分平面図、The partial top view of the magnetic sensor for demonstrating terminal arrangement different from FIG. 磁気抵抗効果素子の積層構造を説明するための断面図、Sectional drawing for demonstrating the laminated structure of a magnetoresistive effect element, 磁気センサの回路図、Circuit diagram of magnetic sensor, 図１とは異なる本実施形態の磁気エンコーダの模式図、FIG. 1 is a schematic diagram of a magnetic encoder of the present embodiment different from FIG. 従来における磁気エンコーダを構成する磁気センサの平面図、The top view of the magnetic sensor which comprises the conventional magnetic encoder,
符号の説明Explanation of symbols
７　反強磁性層
８　固定磁性層
９　非磁性層
１０　フリー磁性層
１１　保護層
１２　素子部
１３　接続部
２０　磁気エンコーダ
２１　磁石
２２　磁気センサ
２３　基板
２４ａ～２４ｈ　磁気抵抗効果素子
５０　Ａ相第１出力端子（Ｖａ１）
５１　Ａ相第２出力端子（Ｖａ２）
５２　入力端子（Ｖｄｄ）
５４　Ｂ相第１出力端子（Ｖｂ１）
５５　Ｂ相第２出力端子（Ｖｂ２）
６６、６７　グランド端子（ＧＮＤ）
５８、６０　差動増幅器
７７、７８　入力配線層
７９、８０　グランド配線層
８１、８２、８３、８４　出力配線層
８９　回転ドラム 7 Antiferromagnetic layer 8 Fixed magnetic layer 9 Nonmagnetic layer 10 Free magnetic layer 11 Protective layer 12 Element portion 13 Connection portion 20 Magnetic encoder 21 Magnet 22 Magnetic sensor 23 Substrate 24a to 24h Magnetoresistive element 50 A-phase first output terminal (Va1)
51 A-phase second output terminal (Va2)
52 Input terminal (Vdd)
54 B-phase first output terminal (Vb1)
55 Phase B second output terminal (Vb2)
66, 67 Ground terminal (GND)
58, 60 Differential amplifier 77, 78 Input wiring layer 79, 80 Ground wiring layer 81, 82, 83, 84 Output wiring layer 89 Rotating drum

Claims (9)

  1. 　相対移動方向に交互にＮ極とＳ極が着磁された着磁面を有する磁界発生部材の前記着磁面から離れた位置に配置され、基板表面に外部磁界に対して電気抵抗値が変化する磁気抵抗効果を利用した複数個の磁気抵抗効果素子を有しており、
    　複数のブリッジ回路を構成する数の前記磁気抵抗効果素子が前記基板表面に設けられており、前記磁気抵抗効果素子は、前記相対移動方向、及び前記相対移動方向と直交する縦方向に、マトリクス状に配置されており、
    　入力端子及びグランド端子のうちいずれか一方の端子が１個だけ設けられ、他方の端子が複数設けられており、
    　前記入力端子、前記グランド端子、及び出力端子が、夫々、前記相対移動方向に間隔を空けて並設された各磁気抵抗効果素子の間の領域に配置され、各端子と各磁気抵抗効果素子とが配線層で電気的に接続されて複数の前記ブリッジ回路を構成していることを特徴とする磁気センサ。     A magnetic field generating member having a magnetized surface in which N and S poles are alternately magnetized in the relative movement direction is disposed at a position away from the magnetized surface, and the electric resistance value changes with respect to an external magnetic field on the substrate surface. Having a plurality of magnetoresistive elements utilizing the magnetoresistive effect,
    A number of the magnetoresistive effect elements constituting a plurality of bridge circuits are provided on the substrate surface, and the magnetoresistive effect elements are arranged in a matrix in the relative movement direction and in the vertical direction perpendicular to the relative movement direction. Are located in
    Only one of the input terminal and the ground terminal is provided, and the other terminal is provided in plurality.
    The input terminal, the ground terminal, and the output terminal are respectively disposed in regions between the magnetoresistive elements arranged in parallel with an interval in the relative movement direction, and the terminals, the magnetoresistive elements, Are electrically connected by a wiring layer to form a plurality of the bridge circuits.
  2. 　前記入力端子及び前記グランド端子のうち１個だけ設けられたほうの端子が磁気抵抗効果素子形成領域の略中心位置に配置される中心端子であり、複数設けられる他方の端子、及び前記出力端子は、夫々、前記中心端子を中心として略点対称の位置に設けられる請求項１記載の磁気センサ。 Of the input terminal and the ground terminal, the terminal provided with only one is a center terminal disposed at a substantially central position of the magnetoresistive effect element formation region, the other provided plural terminals, and the output terminal The magnetic sensor according to claim 1, wherein the magnetic sensor is provided at a substantially point-symmetrical position about the center terminal.
  3. 　前記中心端子は入力端子で、他方の端子がグランド端子である請求項１記載の磁気センサ。 The magnetic sensor according to claim 1, wherein the center terminal is an input terminal and the other terminal is a ground terminal.
  4. 　第１の磁気抵抗効果素子、第２の磁気抵抗効果素子、第３の磁気抵抗効果素子及び第４の磁気抵抗効果素子がＡ相のブリッジ回路を構成し、前記第１の磁気抵抗効果素子と前記第２の磁気抵抗効果素子とがＡ相第１出力端子Ｖａ１を介して直列接続されるとともに、前記第３の磁気抵抗効果素子と前記第４の磁気抵抗効果素子とがＡ相第２出力端子Ｖａ２を介して直列接続されており、
    　前記第１の磁気抵抗効果素子と前記第３の磁気抵抗効果素子とが前記入力端子を介して接続され、前記第２の磁気抵抗効果素子と前記第４の磁気抵抗効果素子とが前記グランド端子を介して接続されており、
    　前記第１の磁気抵抗効果素子と前記第２の磁気抵抗効果素子、及び第３の磁気抵抗効果素子及び第４の磁気抵抗効果素子が、夫々、前記相対移動方向に、所定の中心間距離を空けて配置されているとともに、
    　前記第１の磁気抵抗効果素子と前記第４の磁気抵抗効果素子、及び第２の磁気抵抗効果素子と前記第３の磁気抵抗効果素子が、前記相対移動方向と直交する縦方向に並設されており、
    　第５の磁気抵抗効果素子、第６の磁気抵抗効果素子、第７の磁気抵抗効果素子及び第８の磁気抵抗効果素子がＢ相のブリッジ回路を構成し、前記第５の磁気抵抗効果素子と前記第６の磁気抵抗効果素子とがＢ相第１出力端子Ｖｂ１を介して直列接続されるとともに、前記第７の磁気抵抗効果素子と前記第８の磁気抵抗効果素子とがＢ相第２出力端子Ｖｂ２を介して直列接続されており、
    　前記第５の磁気抵抗効果素子と前記第７の磁気抵抗効果素子とが前記入力端子を介して接続され、前記第６の磁気抵抗効果素子と前記第８の磁気抵抗効果素子とが前記グランド端子を介して接続されており、
    　前記第５の磁気抵抗効果素子と前記第６の磁気抵抗効果素子、及び第７の磁気抵抗効果素子及び第８の磁気抵抗効果素子が、夫々、前記相対移動方向に距離を空けて配置されているとともに、前記Ａ相のブリッジ回路を構成する各磁気抵抗効果素子間の中心間距離の半分だけ前記相対移動方向にずれた位置に配置され、さらに、
    　前記第５の磁気抵抗効果素子と前記第８の磁気抵抗効果素子、及び前記第６の磁気抵抗効果素子と前記第７の磁気抵抗効果素子が、前記相対移動方向と直交する縦方向に並設されており、
    　前記入力端子及び前記グランド端子のうち１個だけ設けられたほうの端子が前記Ａ相のブリッジ回路及び前記Ｂ相のブリッジ回路に対する共通端子であり、他方の端子は２個設けられており、前記他方の端子のうち第１の端子は、Ａ相のブリッジ回路を構成する一方の直列回路、及びＢ相のブリッジ回路を構成する一方の直列回路の共通端子であり、前記他方の端子のうち第２の端子は、Ａ相のブリッジ回路を構成する他方の直列回路、及びＢ相のブリッジ回路を構成する他方の直列回路の共通端子である請求項１ないし３のいずれかに記載の磁気センサ。     The first magnetoresistive element, the second magnetoresistive element, the third magnetoresistive element, and the fourth magnetoresistive element form an A-phase bridge circuit, and the first magnetoresistive element and The second magnetoresistive element is connected in series via the A-phase first output terminal Va1, and the third magnetoresistive element and the fourth magnetoresistive element are connected to the A-phase second output. Are connected in series via the terminal Va2,
    The first magnetoresistive element and the third magnetoresistive element are connected via the input terminal, and the second magnetoresistive element and the fourth magnetoresistive element are connected to the ground terminal. Connected through
    The first magnetoresistive element, the second magnetoresistive element, the third magnetoresistive element, and the fourth magnetoresistive element each have a predetermined center-to-center distance in the relative movement direction. As well as being arranged
    The first magnetoresistive effect element and the fourth magnetoresistive effect element, and the second magnetoresistive effect element and the third magnetoresistive effect element are juxtaposed in a vertical direction perpendicular to the relative movement direction. And
    The fifth magnetoresistive element, the sixth magnetoresistive element, the seventh magnetoresistive element, and the eighth magnetoresistive element constitute a B-phase bridge circuit, and the fifth magnetoresistive element and The sixth magnetoresistive element is connected in series via the B-phase first output terminal Vb1, and the seventh magnetoresistive element and the eighth magnetoresistive element are connected to the B-phase second output. Are connected in series via the terminal Vb2,
    The fifth magnetoresistive effect element and the seventh magnetoresistive effect element are connected via the input terminal, and the sixth magnetoresistive effect element and the eighth magnetoresistive effect element are connected to the ground terminal. Connected through
    The fifth magnetoresistive effect element, the sixth magnetoresistive effect element, the seventh magnetoresistive effect element, and the eighth magnetoresistive effect element are respectively arranged at a distance in the relative movement direction. And is arranged at a position shifted in the relative movement direction by half the center-to-center distance between the magnetoresistive elements constituting the A-phase bridge circuit,
    The fifth magnetoresistive effect element and the eighth magnetoresistive effect element, and the sixth magnetoresistive effect element and the seventh magnetoresistive effect element are arranged in parallel in a vertical direction perpendicular to the relative movement direction. Has been
    Of the input terminal and the ground terminal, only one terminal is a common terminal for the A-phase bridge circuit and the B-phase bridge circuit, and the other terminal is provided in two, Of the other terminals, the first terminal is a common terminal of one series circuit constituting the A-phase bridge circuit and one series circuit constituting the B-phase bridge circuit. 4. The magnetic sensor according to claim 1, wherein the second terminal is a common terminal of the other series circuit constituting the A-phase bridge circuit and the other series circuit constituting the B-phase bridge circuit.
  5. 　前記Ａ相のブリッジ回路を構成する各磁気抵抗効果素子に対する前記Ｂ相のブリッジ回路を構成する各磁気抵抗効果素子のずれ方向に向けて、各磁気抵抗効果素子の間の前記相対移動方向への領域が、第１の領域、第２の領域及び第３の領域の順に並設されており、
    　前記Ａ相第１出力端子Ｖａ１と前記Ａ相第２出力端子Ｖａ２が共に前記第１の領域に設けられ、前記Ｂ相第１出力端子Ｖｂ１及び前記Ｂ相第２出力端子Ｖｂ２が共に前記第３の領域に配置される請求項４記載の磁気センサ。     In the direction of the relative movement between the magnetoresistive effect elements toward the shift direction of the magnetoresistive effect elements constituting the B phase bridge circuit with respect to the magnetoresistive effect elements constituting the A phase bridge circuit The regions are arranged in the order of the first region, the second region, and the third region,
    The A-phase first output terminal Va1 and the A-phase second output terminal Va2 are both provided in the first region, and the B-phase first output terminal Vb1 and the B-phase second output terminal Vb2 are both the third. The magnetic sensor according to claim 4, which is disposed in the region of
  6. 　前記入力端子及び前記グランド端子のうち１個だけ設けられたほうの端子が前記第２の領域内に配置される中心端子であり、前記Ａ相第１出力端子Ｖａ１と、前記Ｂ相第１出力端子Ｖｂ１とが前記中心端子を中心として略点対称の位置に配置され、前記Ａ相第２出力端子Ｖａ２と、前記Ｂ相第２出力端子Ｖｂ２とが前記中心端子を中心として略点対称の位置に配置されている請求項５記載の磁気センサ。 Of the input terminal and the ground terminal, the terminal provided with only one is a center terminal disposed in the second region, and the A-phase first output terminal Va1 and the B-phase first output. The terminal Vb1 is disposed at a substantially point-symmetrical position about the center terminal, and the A-phase second output terminal Va2 and the B-phase second output terminal Vb2 are approximately point-symmetrical about the center terminal. The magnetic sensor according to claim 5, wherein
  7. 　前記縦方向に並設された各磁気抵抗効果素子の間には、２本以下の前記配線層が配置される請求項１ないし６のいずれかに記載の磁気センサ。 The magnetic sensor according to any one of claims 1 to 6, wherein two or less wiring layers are arranged between the magnetoresistive elements arranged in parallel in the vertical direction.
  8. 　請求項１ないし７のいずれかに記載された磁気センサと、前記磁界発生部材とを有してなることを特徴とする磁気エンコーダ。 A magnetic encoder comprising the magnetic sensor according to any one of claims 1 to 7 and the magnetic field generating member.
  9. 　前記Ｎ極と前記Ｓ極の中心間距離をλとしたとき、直列接続される一対の前記磁気抵抗効果素子は、前記相対移動方向に、λの中心間距離を空けて配置されている請求項８記載の磁気エンコーダ。 The pair of magnetoresistive elements connected in series are arranged with a distance between the centers of λ in the relative movement direction, where λ is the distance between the centers of the N and S poles. 8. The magnetic encoder according to 8.
PCT/JP2008/073870 2008-01-08 2008-12-27 Magnetic sensor and magnetic encoder WO2009087937A1 (en)

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