WO2020065941A1 - Acoustic wave modulation element and physical quantity sensor - Google Patents

Acoustic wave modulation element and physical quantity sensor Download PDF

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Publication number
WO2020065941A1
WO2020065941A1 PCT/JP2018/036364 JP2018036364W WO2020065941A1 WO 2020065941 A1 WO2020065941 A1 WO 2020065941A1 JP 2018036364 W JP2018036364 W JP 2018036364W WO 2020065941 A1 WO2020065941 A1 WO 2020065941A1
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Prior art keywords
magnetic flux
piezoelectric substrate
elastic wave
pair
main surface
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PCT/JP2018/036364
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French (fr)
Japanese (ja)
Inventor
鈴木　英治
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Tdk株式会社
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Priority to JP2020547815A priority Critical patent/JP6801832B2/en
Priority to PCT/JP2018/036364 priority patent/WO2020065941A1/en
Publication of WO2020065941A1 publication Critical patent/WO2020065941A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
    • G01K7/32—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using change of resonant frequency of a crystal
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • 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
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B5/00—Generation of oscillations using amplifier with regenerative feedback from output to input
    • H03B5/30—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element being electromechanical resonator
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/125—Driving means, e.g. electrodes, coils
    • H03H9/145—Driving means, e.g. electrodes, coils for networks using surface acoustic waves

Definitions

  • the present invention relates to an elastic wave modulating element and a physical quantity sensor, and more particularly to an elastic wave modulating element capable of detecting a physical quantity of an object to be detected based on a change in propagation characteristics of a surface acoustic wave.
  • a delay line type or resonator type sensor using a surface acoustic wave (hereinafter also referred to as SAW (Surface Acoustic Wave)).
  • SAW Surface Acoustic Wave
  • As a configuration of the delay line type SAW sensor for example, a LiNbO3 substrate, a pair of comb electrode portions provided on the substrate, and an amorphous TbFe2 disposed in a SAW propagation region between the pair of comb electrode portions.
  • a SAW delay line including a film has been proposed (Non-Patent Document 1).
  • a transponder including a surface acoustic wave element having a piezoelectric substrate and a comb electrode and an antenna means, a drive signal is transmitted to the transponder, and a response from the transponder is provided.
  • a wireless SAW sensor including an interrogator for receiving a signal has been proposed.
  • This SAW sensor has a magnetostrictive film having a substantially rectangular shape having sides coinciding with the propagation direction of the surface acoustic wave, and having a magnetostrictive film separated from the comb-teeth electrode.
  • the stress acting on the piezoelectric substrate is detected based on the time difference between the echo corresponding to the reflected wave from the substrate and the echo corresponding to the reflected wave from the anti-comb electrode side end of the rectangular magnetostrictive film (Patent Document 1). ).
  • the so-called ⁇ E effect of the magnetostrictive film depends on the change in the magnetization state in the magnetostrictive film, the ⁇ E effect hardly occurs when the amount of change in the magnetization state is small. Therefore, when the stress acting on the piezoelectric substrate is small, the stress acting on the piezoelectric substrate cannot be sufficiently detected, and the sensitivity may not be good.
  • the external magnetic field (magnetic field) applied to the magnetostrictive film is small, the change in the magnetization state due to the external magnetic field is small, so that the ⁇ E effect is also small, and the magnetic field sensitivity as a sensor may not be good.
  • An object of the present invention is to provide an elastic wave modulation element and a physical quantity sensor capable of detecting a physical quantity of an object to be detected with improved sensitivity compared to the related art.
  • the present invention provides the following means.
  • a piezoelectric substrate A first electrode unit attached to the piezoelectric substrate and exciting an elastic wave to the piezoelectric substrate;
  • Magnetostrictive material portion provided in or near the elastic wave existence region,
  • the magnetostrictive material section includes: A pair of magnetic flux transmission units provided on one main surface of the piezoelectric substrate and capable of transmitting a magnetic flux of an external magnetic field, A magnetic flux collection unit provided between the pair of magnetic flux transmission units on the one main surface, and disposed on or near the elastic wave propagation path; Having, An elastic wave modulating element characterized by the above-mentioned.
  • Each of the pair of magnetic flux propagation sections has a shape in which a cross-sectional area decreases along a direction from one end on the side opposite to the magnetic flux collection section to the other end on the magnetic flux collection section side,
  • a magnetic flux in the magnetic flux collecting unit is formed along a direction perpendicular to a propagation direction of the elastic wave;
  • the pair of magnetic flux transmission units and the magnetic flux collection unit are disposed on one main surface of the piezoelectric substrate,
  • a magnetic flux in the magnetic flux collecting unit is formed along a propagation direction of the elastic wave;
  • the pair of magnetic flux transmission units and the magnetic flux collection unit are disposed on one main surface of the piezoelectric substrate,
  • the first electrode portion and the second electrode portion are disposed on the one main surface at positions corresponding to a pair of openings provided in the pair of magnetic flux transmission portions, or
  • the elastic wave modulating element according to the above [3] which is arranged on a surface and below the pair of magnetic flux propagation parts, or arranged on the other main surface of the piezoelectric substrate.
  • the magnetic flux in the magnetic flux collecting unit is formed along the propagation direction of the elastic wave
  • the pair of magnetic flux transmission units and the magnetic flux collection unit are disposed on one main surface of the piezoelectric substrate
  • the first electrode portion and the second electrode portion are disposed on the one main surface of the piezoelectric substrate and below the magnetic flux collecting portion, or on the other main surface of the piezoelectric substrate.
  • the elastic wave modulation device according to the above [6] which is arranged.
  • the first electrode portion is constituted by a pair of comb-tooth electrodes arranged so as to face each other so that the teeth are alternately arranged,
  • the elastic wave according to any one of [1] to [8], wherein the second electrode unit includes another pair of comb-shaped electrodes arranged so as to face each other so that the teeth are alternately arranged.
  • Modulation element [10] The elasticity according to any of [1] to [8], wherein the first electrode portion and the second electrode portion are a pair of comb-shaped electrodes for exciting or receiving an elastic wave to the piezoelectric substrate. Wave modulation element.
  • the magnetic flux collection unit is disposed at a position including the one reflector on a projection plane projected in the thickness direction of the piezoelectric substrate, and the one reflector is provided on the one main surface of the piezoelectric substrate.
  • the device according to any one of [1] to [10], further including a pair of reflectors attached to the piezoelectric substrate and arranged on both sides of the first electrode portion and the second electrode portion.
  • Elastic wave modulator [14]
  • the magnetic flux collecting portion is disposed at a position including the pair of reflectors on a projection plane projected in a thickness direction of the piezoelectric substrate, and the pair of reflectors is disposed on the one main surface of the piezoelectric substrate.
  • the elastic wave modulating element according to the above [13], which is arranged above and below the magnetic flux collecting part.
  • a physical quantity sensor comprising: the elastic wave modulation element according to any one of [1] to [14]; and a circuit unit that detects modulation of the elastic wave modulation element.
  • the present invention it is possible to detect a physical quantity of an object to be detected with high accuracy and a physical quantity of an object to be detected with higher accuracy than before.
  • FIG. 3 is a diagram showing a third modification of the elastic wave modulation element in FIG. 1, where (a) is a plan view and (b) is a cross-sectional view along line III-III. It is a figure which shows roughly the structure of the elastic wave modulation element which concerns on 3rd Embodiment of this invention, (a) is a top view, (b) is sectional drawing which follows the line IV-IV. (A) is a top view which shows roughly the structure of the physical quantity sensor provided with the elastic wave modulation element which concerns on 4th Embodiment of this invention, (b) is a top view which shows the modification of 4th Embodiment. It is. It is a top view showing roughly composition of a physical quantity sensor provided with an elastic wave modulation element concerning a 5th embodiment of the present invention.
  • FIGS. 1A and 1B are diagrams schematically showing a configuration of a physical quantity sensor including an elastic wave modulation element according to a first embodiment of the present invention, wherein FIG. 1A is a plan view, and FIG. 1B is a cross-section along line II. FIG. 3C is a bottom view.
  • the physical quantity sensor is a delay line type
  • the characteristic portions may be enlarged for convenience, and the dimensional ratios and the like of the respective components are not limited to those illustrated. I do.
  • the elastic wave modulating element 10 includes a piezoelectric substrate 11, a first electrode unit 12 attached to the piezoelectric substrate 11, and exciting the piezoelectric substrate 11 with an elastic wave.
  • a second electrode portion 13 attached to the piezoelectric substrate 11 for receiving an elastic wave, and a magnetostrictive material portion 15 provided in or near the elastic wave existing region.
  • the elastic wave modulation element 10 is connected to a detection circuit (not shown) that detects the modulation of the elastic wave based on a signal from the elastic wave modulation element 10.
  • the sensor 1 is configured.
  • the physical quantity sensor 1 includes the elastic wave modulation element 10 and the detection circuit unit, and detects the physical quantity of the detection target based on a change in the propagation characteristic of the elastic wave. Further, the physical quantity sensor 1 includes a magnetic field applying unit 16 that applies a magnetic field to the magnetostrictive material unit 15 on the piezoelectric substrate 11. A magnetic field (magnetic field) is formed in the portion 15.
  • the physical quantity sensor 1 is, for example, a pressure sensor, a magnetic sensor, or the like.
  • the piezoelectric substrate 11 is selected from the group consisting of SiO2, LiNbO3, LiTaO3, BaTiO3, PbTiO3, Pb (Zr.Ti) O3 (lead zirconate titanate), La3Ga5SiO14, Li2B4O7, AlN (aluminum nitride), ZnO and diamond. It is composed of at least one material. Since the piezoelectric substrate 11 is made of at least one material selected from the above group, it is possible to efficiently generate an elastic wave in the piezoelectric substrate 11.
  • the first electrode section 12 is composed of, for example, a pair of comb-tooth electrodes 12a and 12b opposed to each other so that the teeth are alternately arranged (FIG. 1A).
  • the first electrode unit 12 corresponds to an input electrode that generates an elastic wave, particularly a surface acoustic wave (SAW) based on an input signal from the input unit 17.
  • SAW surface acoustic wave
  • the pitch of the teeth of the pair of comb electrodes 12a and 12b constituting the first electrode unit 12 can be set arbitrarily, but is constant at, for example, ⁇ / 4 ( ⁇ is the wavelength of the SAW).
  • the second electrode section 13 is composed of, for example, a pair of comb-tooth electrodes 13a and 13b (another pair of comb-tooth electrodes) arranged to face each other such that the teeth are alternately arranged (FIG. 1). (A)).
  • the second electrode unit 13 corresponds to an output electrode that receives an elastic wave, particularly SAW, and outputs an output signal corresponding to the elastic wave to the detection circuit unit via the output unit 18.
  • the pitch of the teeth of the pair of comb electrodes 13a and 13b constituting the second electrode unit 13 can be arbitrarily set, but is, for example, the same as the pitch of the teeth of the pair of comb electrodes 12a and 12b.
  • the first electrode section 12 and the second electrode section 13 are not particularly limited as long as they are suitable as electrode materials.
  • Al aluminum
  • Au gold
  • Cu copper
  • Ti titanium
  • It is composed of a material such as Cr (chromium) or an alloy thereof.
  • the magnetostrictive material portion 15 is provided on one main surface 11a of the piezoelectric substrate 11 and is capable of transmitting a magnetic flux of an external magnetic field, and a pair of magnetic flux transmitting portions on the one main surface 11a. And a magnetic flux collector 15c provided between the elastic wave propagation paths 14 and 15a and 15b. In the present embodiment, the magnetic flux collecting portion 15c is formed integrally with the pair of magnetic flux transmitting portions 15a and 15b.
  • Each of the pair of magnetic flux transmitting portions 15a and 15b has a shape in which the cross-sectional area decreases along a direction from one end opposite to the magnetic flux collecting portion 15c toward the other end of the magnetic flux collecting portion 15c. Is preferred. Further, it is preferable that the minimum value of the cross-sectional area of the magnetic flux collection unit 15c perpendicular to the magnetic field direction is equal to or smaller than the minimum value of the cross-sectional area of the pair of magnetic flux transmission units 15a and 15b.
  • the pair of magnetic flux transmitting portions 15a and 15b have a flat trapezoidal shape, and the magnetic flux collecting portion 15c has a rectangular shape (FIG. 1A).
  • the magnetostrictive material portion 15 has a constricted shape and the narrow magnetic flux collecting portion 15c is arranged between the pair of wide magnetic flux transmitting portions 15a and 15b, a magnetic field is applied to the magnetostrictive material portion 15. Then, the magnetic flux can be reliably collected by the magnetic flux collecting unit 15c.
  • the magnetic flux collection unit 15c is disposed between the first electrode unit 12 and the second electrode unit 13 on the projection plane in the thickness direction of the piezoelectric substrate 11, for example (see FIGS. 1A and 1C).
  • the magnetic flux in the magnetic flux collecting portion 15c is formed along a direction perpendicular to the propagation direction of the elastic wave.
  • the pair of magnetic flux transmitting parts 15a, 15b and the magnetic flux collecting part 15c are arranged on one main surface 11a of the piezoelectric substrate 11, and the first electrode part 12 and the second electrode part 13 It is arranged on one main surface 11a.
  • the magnetostrictive material portion 15 is arranged in contact with the one main surface 11a of the piezoelectric substrate 11 through which the elastic wave propagates, The change in the propagation speed of the elastic wave due to the magnetostriction can be further increased.
  • the magnetostrictive material portion 15 includes Co, Ni, Fe, CoNi, NiFe, CoFe, FeAl, CoPt, NiCoCr, FeB, CoFeB, CoFeSiB, FeBSiP, FeBSiC, Ni2MnGa, FeCoNiBSi, TbFeCo, Co ferrite, Ni ferrite, Cu ferrite, and Li.
  • the magnetostrictive material 15 is made of at least one material selected from the above group, magnetostriction can be efficiently generated in the magnetostrictive material 15.
  • the magnetostrictive material portion 15 is formed of, for example, a magnetostrictive film.
  • the pair of magnetic flux transmitting portions 15a and 15b and the magnetic flux collecting portion 15c are also formed of the magnetostrictive film.
  • the thickness of the magnetostrictive material portion 15 is 10 nm to 10 ⁇ m.
  • the method of forming the magnetostrictive material portion 15 is not limited, but it can be formed by sputtering such as magnetron sputtering.
  • the magnetic field applying unit 16 applies a magnetic field to the magnetostrictive material unit 15 to cause the magnetostrictive material unit 15 to generate magnetostriction.
  • the magnetic field (magnetic field) applied to the magnetostrictive material portion 15 is preferably a static magnetic field capable of obtaining a magnetostrictive effect, but may be a fluctuating magnetic field.
  • the magnetic field applying section 16 is configured by, for example, a permanent magnet.
  • the magnetic field applying unit 16 can apply a bias magnetic field for setting the magnetization state to an optimum operation origin. Further, it is preferable that another magnetic field applying unit is provided on the side of the magnetostrictive material unit 15 opposite to the magnetic field applying unit 16.
  • the piezoelectric substrate 11 is configured to generate, for example, an SH wave (hereinafter, also referred to as SH-SAW) of the surface acoustic wave
  • SH-SAW SH wave
  • the light propagates through the propagation path 14 between the first electrode unit 12 and the second electrode unit 13 and reaches the second electrode unit 13.
  • a stress is applied to the piezoelectric substrate 11 and the stress also acts on the magnetostrictive material portion 15, the magnetization state of the magnetostrictive material portion 15 changes, and as a result, the elastic modulus of the magnetostrictive material portion 15, particularly the magnetic flux collecting portion 15c is reduced.
  • the ⁇ E effect of the magnetostrictive material portion depends on the change in the magnetization state in the magnetostrictive material portion. Therefore, if the amount of change in the magnetization state is small, the ⁇ E effect hardly occurs.
  • the magnetic flux density of the magnetic flux collecting portion 15c is smaller than the magnetic flux density of the pair of magnetic flux transmitting portions 15a and 15b. Get higher. Therefore, the magnetostriction in the magnetic flux collecting portion 15c is larger than the magnetostriction in the non-magnetizing portion when the magnetic flux collecting portion 15c is not provided.
  • the propagation speed of the SH-SAW propagating through the propagation path 14 changes greatly due to the increase in the magnetostrictive effect ( ⁇ E effect) caused by the magnetic flux collection in addition to the ⁇ E effect caused by the change in the magnetization state. . Therefore, for example, when a small stress is generated in the piezoelectric substrate 11, a change in the SH-SAW propagation speed can be sufficiently generated as compared with the case where the magnetic flux collecting portion 15c is not provided in the magnetostrictive material portion 15.
  • the physical quantity sensor 1 can function as a highly sensitive pressure sensor. Further, even when a small external magnetic field is applied to the magnetostrictive material portion 15, a change in the SH-SAW propagation speed can be sufficiently generated. Therefore, the physical quantity sensor 1 of the present embodiment can also function as a high-sensitivity magnetic sensor.
  • the detection circuit detects the physical quantity of the detection target based on a change in the propagation characteristic of the SAW.
  • the detected object include living bodies, walls and columns of structures such as buildings and bridges, electronic devices such as computers, and home appliances such as televisions and refrigerators.
  • the physical quantities include, for example, magnetic fields, torques, and the like. , Pressure, temperature, gas amount and the like.
  • the magnetostrictive material portion 15 is provided between the pair of magnetic flux propagation portions 15a and 15b on one main surface 11a, and is disposed on the elastic wave propagation path 14. Since the magnetic flux collecting portion 15c is provided, the magnetostriction in the magnetic flux collecting portion 15c can be increased when an external magnetic field is applied to the magnetostrictive material portion 15. Therefore, a change in the propagation speed of the SH-SAW propagating through the propagation path 14 can be sufficiently and efficiently generated, and the sensitivity is improved as compared with the related art, and the magnetic field or stress acting on the piezoelectric substrate 11 can be accurately detected. Can be.
  • FIG. 2A and 2B are diagrams showing a modification of the physical quantity sensor including the elastic wave modulation element according to the second embodiment of the present invention, wherein FIG. 2A is a plan view, FIG. 2B is a cross-sectional view along line II-II, (C) is a bottom view.
  • the present embodiment is different from the first embodiment in that the magnetostrictive material portion 15 is provided on the main surface 11b of the piezoelectric substrate 11 opposite to the first electrode portion 12 and the second electrode portion 13. .
  • the other parts are the same as in the first embodiment, and therefore, the parts different from the first embodiment will be described below.
  • the magnetostrictive material portion 21 is provided on one main surface 11b of the piezoelectric substrate 11, and is capable of transmitting a magnetic flux of an external magnetic field.
  • a magnetic flux collecting part 21c provided between the pair of magnetic flux transmitting parts 21a and 21b on one main surface 11b and arranged near the elastic wave propagation path 14 (for example, immediately below the propagation path 14).
  • the pair of magnetic flux transmission units 21a and 21b and the magnetic flux collection unit 21c are arranged on one main surface 11b of the piezoelectric substrate 11, and the first electrode unit 12 and the second electrode unit 13 It is arranged on the other main surface 11 a of the piezoelectric substrate 11. Also in this configuration, the magnetic flux collecting portion 21c is disposed between the first electrode portion 12 and the second electrode portion 13 on the projection surface in the thickness direction of the piezoelectric substrate 11 (FIGS. 2A and 2C). )reference).
  • the piezoelectric substrate is configured to generate a Rayleigh wave of the surface acoustic waves
  • the Rayleigh wave involves displacement in a direction perpendicular to the surface of the piezoelectric substrate. Therefore, when the magnetostrictive material portion is provided on the same main surface as the first and second electrode portions, the Rayleigh wave propagates to the magnetostrictive material portion and the attenuation increases, and the SAW propagation speed cannot be sufficiently detected. There is.
  • a pair of magnetic flux propagation portions 21a and 21b and a magnetic flux collection portion 21c are provided on the main surface 11b of the piezoelectric substrate 11 opposite to the first electrode portion 12 and the second electrode portion 13. Therefore, when the Rayleigh wave propagates through the propagation path 14 between the first electrode unit 12 and the second electrode unit 13 and reaches the second electrode unit 13, the other main surface 11 a of the piezoelectric substrate 11 The propagation of the propagating Rayleigh wave to the magnetostrictive material portion 21, in particular, the magnetic flux collecting portion 21c can be suppressed.
  • the magnetostrictive effect ( ⁇ E effect) due to the magnetic flux collection can be increased in addition to the ⁇ E effect due to the change in the magnetization state, and the attenuation of the Rayleigh wave propagating through the propagation path 14 can be reduced. This makes it possible to sufficiently and accurately generate a change in the propagation speed of the Rayleigh wave.
  • FIG. 3A is a diagram illustrating a first modification of the elastic wave modulation device 10 in FIG. 1
  • FIG. 3B is a diagram illustrating a second modification.
  • the magnetic flux collecting portion 15c is formed integrally with the pair of magnetic flux transmitting portions 15a and 15b.
  • the present invention is not limited thereto, and the magnetic flux collecting portion is formed separately from the pair of magnetic flux transmitting portions. May be.
  • the magnetic flux collecting portion 31c of the magnetostrictive material portion 31 may be arranged to be separated from the pair of magnetic flux transmitting portions 31a and 31b so as to have a gap.
  • the magnetic flux collecting portion 31c in a plan view of the piezoelectric substrate 11, has a rectangular shape, and each of the pair of magnetic flux transmitting portions 31a and 31b has a flat trapezoidal shape.
  • the magnetic flux collecting portion 32c of the magnetostrictive material portion 32 may be separate from the pair of magnetic flux transmitting portions 32a and 32b, or may be disposed separately.
  • the magnetic flux collecting portion 32c has a rectangular shape
  • the magnetic flux transmitting portion 32a has a triangular shape with a plurality of flat portions 32a-1, 32a-1,.
  • the magnetic flux propagation portion 32b has a plurality of flat portions 32b-1, 32b-1,... And a triangular portion 32b-2.
  • the magnetostriction in the magnetic flux collecting parts 31c and 32c can be increased when an external magnetic field is applied to the magnetostrictive material parts 31 and 32. Further, the degree of freedom in design is improved, and the magnetostrictive material portions 31 and 32 can be easily formed on the piezoelectric substrate 11.
  • FIGS. 4A and 4B are diagrams showing a third modification of the elastic wave modulation device 10 in FIG. 1, wherein FIG. 4A is a plan view, and FIG. 4B is a cross-sectional view along line III-III.
  • the magnetic flux in the magnetic flux collecting portion 15c is formed along the direction perpendicular to the propagation direction of the elastic wave.
  • the present invention is not limited to this. May be formed along.
  • a pair of magnetic flux transmitting portions 33a, 33b and a magnetic flux collecting portion 33c of the magnetostrictive material portion 33 are disposed on one main surface 11a of the piezoelectric substrate 11, and the first electrode portion 12 and the second electrode portion 13 It is arranged on one main surface 11a of the substrate 11 at a position corresponding to the openings 34a and 34b (non-film-forming portions) provided in the pair of magnetic flux propagation portions 33a and 33b.
  • a pair of magnetic flux transmitting portions not having the pair of openings is provided, and the pair of magnetic flux transmitting portions and the magnetic flux collecting portion are disposed on one main surface 11 a of the piezoelectric substrate 11.
  • the second electrode portion 13 may be disposed on one main surface 11a of the piezoelectric substrate 11 and below the pair of magnetic flux transmitting portions. According to the configuration of the present modification, the magnetostriction in the magnetic flux collecting portion 33c can be increased when an external magnetic field is applied to the magnetostrictive material portion 33.
  • a pair of magnetic flux transmitting portions and a magnetic flux collecting portion having no pair of openings are disposed on one main surface 11a of the piezoelectric substrate 11, and the first electrode portion 12 and the second electrode portion 13 It may be arranged on the other main surface 11 b of the substrate 11.
  • the magnetic flux in the magnetic flux collecting portion is formed along the propagation direction of the elastic wave (for example, a direction parallel to the propagation direction), and the pair of magnetic flux transmitting portions 33 a and 33 b and the magnetic flux collecting portion 33 c are formed on one side of the piezoelectric substrate 11.
  • the first electrode portion 12 and the second electrode portion 13 may be arranged on one main surface of the piezoelectric substrate 11 and below the magnetic flux collecting portion 33c.
  • FIG. 5 is a view schematically showing a configuration of an elastic wave modulation element according to a third embodiment of the present invention, where (a) is a plan view and (b) is a cross-sectional view along line IV-IV.
  • the third embodiment is different from the first embodiment in that the first electrode unit 12 and the second electrode unit 13 are provided below the magnetic flux collecting unit.
  • symbol as 1st Embodiment is attached
  • the description is abbreviate
  • the magnetic flux collecting portion 35c of the magnetostrictive material portion 35 is spaced apart from the pair of magnetic flux transmitting portions 35a and 35b so as to have a gap.
  • the magnetic flux collecting portion 35c is disposed at a position including the first electrode portion 12 and the second electrode portion 13 on a projection plane projected in the thickness direction of the piezoelectric substrate 11.
  • the first electrode portion 12 and the second electrode portion 13 are provided on one main surface 11a of the piezoelectric substrate 11 and below the magnetic flux collecting portion 35c. Therefore, the change in the propagation speed of the elastic wave propagating in the propagation path can be more efficiently generated. Therefore, for example, by applying the configuration of the present embodiment to a resonator-type physical quantity sensor, it is possible to improve the sensitivity as compared with the related art and accurately detect the stress applied to the piezoelectric substrate 11.
  • a pair of magnetic flux propagation portions 35a, 35b and a magnetic flux collecting portion 35c are arranged on one main surface 11a of the piezoelectric substrate 11, and the first electrode portion 12 and the second electrode portion 13 are arranged on the other side of the piezoelectric substrate 11. It may be arranged on the main surface 11b.
  • a lower portion of the magnetic flux collecting portion 35c has a comb-tooth shape, between a pair of comb-tooth electrodes 12a and 12b and a pair of comb-tooth electrodes. It is preferable that it penetrates between the electrodes 13a and 13b. Thereby, the magnetic flux collecting portion 35c can be arranged at a position closer to the piezoelectric substrate 11, and the change in the propagation speed of the elastic wave can be more efficiently generated.
  • the elastic wave modulating element includes the piezoelectric substrate 11, the first electrode portion 12, and the second electrode portion from the viewpoint of preventing a short circuit between the electrodes. It is preferable to further include an insulating layer 20 formed so as to cover 13.
  • the magnetic flux in the magnetic flux collecting portion 35c is formed along a direction perpendicular to the propagation direction of the elastic wave. It may be formed along a direction.
  • a pair of magnetic flux transmitting portions 35a and 35b and a magnetic flux collecting portion 35c are arranged on one main surface 11a of the piezoelectric substrate 11, and the first electrode portion 12 and the second electrode portion 13 It may be arranged on one main surface 11a and below magnetic flux collecting portion 35c, or may be arranged on the other main surface 11b of piezoelectric substrate 11.
  • FIG. 6A is a plan view schematically showing a configuration of a physical quantity sensor including an elastic wave modulation element according to a fourth embodiment of the present invention
  • FIG. 6B is a modification of the fourth embodiment.
  • FIG. in the fourth embodiment a case where the physical quantity sensor is a resonator type will be described as an example. Since the physical quantity sensor is the same as that of the third embodiment except that the physical quantity sensor is of the resonator type, parts different from the third embodiment will be described below.
  • the elastic wave modulating element 40 of the physical quantity sensor 2 is attached to the piezoelectric substrate 11, and a pair of reflectors 41a disposed on both sides of the first electrode unit 12 and the second electrode unit 13. , 41b.
  • the first electrode portion 12 is a comb-shaped electrode 42a (one of a pair of comb-shaped electrodes) of a pair of comb-shaped electrodes arranged to face each other such that the teeth are alternately arranged.
  • the second electrode portion 13 forms the comb electrode 42b (the other of the pair of comb electrodes) of the pair of comb electrodes.
  • the comb electrode 42 a of the pair of comb electrodes is connected to the input unit 17, and the comb electrode 42 b is connected to the output unit 18.
  • the elastic wave modulating element 40 forms a so-called one-port resonator.
  • a pair of reflectors 41a and 41b are arranged on both sides of a pair of comb electrodes 42a and 42b, and an elastic wave excited by the pair of comb electrodes 42a and 42b is reflected by a pair of reflection electrodes. It is confined between the vessels 41a and 41b.
  • the pair of comb-teeth electrodes 42a and 42b are arranged on one main surface 11a of the piezoelectric substrate 11 and below the magnetic flux collecting portion 15c, the propagation path 14 is caused by the magnetostriction of the magnetic flux collecting portion 15c.
  • a change in the propagation speed of the propagating elastic wave (or standing wave) can be caused more efficiently. Therefore, by applying the configuration of the present embodiment to a one-port resonator type physical quantity sensor, it is possible to improve the sensitivity as compared with the related art and accurately detect the stress applied to the piezoelectric substrate 11.
  • the elastic wave modulating element 50 of the physical quantity sensor 3 may constitute a so-called two-port resonator. That is, the elastic wave modulation element 50 may further include a pair of reflectors 51 a and 51 b attached to the piezoelectric substrate 11 and arranged on both sides of the first electrode unit 12 and the second electrode unit 13.
  • the first electrode unit 12 is constituted by a pair of comb-teeth electrodes 12a and 12b arranged so as to face each other such that the teeth are alternately arranged. It is composed of a pair of comb-tooth electrodes 13a and 13b arranged so as to face each other alternately.
  • the pair of comb electrodes 12a and 12b are connected to the input unit 17, and the pair of comb electrodes 13a and 13b are connected to the output unit 18. Further, the magnetostrictive material portion 15 is provided on one main surface 11a of the piezoelectric substrate 11 and is capable of transmitting a magnetic flux of an external magnetic field.
  • a magnetic flux collecting portion 36c provided between the propagation portions 36a and 36b and arranged near the elastic wave propagation path 14;
  • the pair of comb electrodes 12a and 12b and the pair of comb electrodes 13a and 13b are both disposed on one main surface 11a of the piezoelectric substrate 11 and below the magnetic flux collecting portion 36c. Due to the magnetostriction of the magnetic flux collecting portion 36c, a change in the propagation speed of the elastic wave (or the standing wave) propagating through the propagation path can be caused more efficiently.
  • the configuration of the elastic wave modulation element 50 to the two-port resonator type physical quantity sensor, the sensitivity is improved as compared with the conventional configuration by the same mechanism as that of the configuration of FIG. The stress acting on the piezoelectric substrate 11 can be accurately detected.
  • FIG. 7 is a plan view schematically showing a configuration of a physical quantity sensor including an elastic wave modulation element according to a fifth embodiment of the present invention.
  • the physical quantity sensor includes a delay line type elastic wave modulation element and an antenna unit
  • the physical quantity sensor is the same as the third embodiment (FIG. 6A) except that the physical quantity sensor includes a delay line-type elastic wave modulation element and an antenna unit, and therefore, different points from the third embodiment will be described below.
  • the elastic wave modulating element 60 of the physical quantity sensor 4 is attached to the piezoelectric substrate 11, and the first electrode unit 12 and the second electrode unit 13 for exciting or receiving the elastic wave to the piezoelectric substrate 11, It includes one reflector 61 attached to the substrate 11 and arranged on one side of the magnetic flux collecting portion 15c.
  • the first electrode unit 12 and the second electrode unit are a pair of comb-teeth electrodes 43a and 43b that excite or receive an elastic wave on the piezoelectric substrate 11.
  • the comb electrode 43a of the pair of comb electrodes 43a and 43b is connected to the antenna unit 19, and the comb electrode 43b is grounded.
  • the first electrode portion 12 and the second electrode portion 13 are arranged on one main surface 11a of the piezoelectric substrate 11 and on the other side of the magnetic flux collecting portion 15c.
  • the first electrode portion 12 and the second electrode portion 13 may be arranged on one main surface 11a of the piezoelectric substrate 11 and below the magnetic flux collecting portion 13c.
  • the elastic wave modulating element 60 when a radio wave is received by the antenna unit 19, the elastic wave excited by the pair of comb-teeth electrodes 43a and 43b reaches the reflector 61 via the propagation path 14 of the piezoelectric substrate 11. After that, the reflected wave generated by the reflection at the reflector 61 reaches the pair of comb-teeth electrodes 43 a and 43 b via the propagation path 14, and the radio wave is transmitted from the antenna unit 19.
  • the magnetic flux collecting portion 15c is arranged on the elastic wave propagation path 14, the change in the propagation speed of the elastic wave propagating through the propagation path can be more efficiently caused by the magnetostriction of the magnetic flux collecting portion 15c. Can be.
  • the configuration of the present embodiment to a physical quantity sensor including a delay line type elastic wave modulation element and an antenna unit, the sensitivity or the magnetic field acting on the piezoelectric substrate 11 can be wirelessly improved by improving the sensitivity compared to the related art. It is possible to detect with high accuracy.
  • the elastic wave modulating element 60 in FIG. 7 includes one reflector, but is not limited thereto, and may include a pair of reflectors disposed on both sides of the one electrode unit and the second electrode unit. Good. At this time, the first electrode portion and the second electrode portion may be arranged on one main surface 11a of the piezoelectric substrate 11 and below the magnetic flux collecting portion (see FIGS. 6A and 6B). ).
  • the pair of reflectors 41a and 41b are attached to both sides of the magnetic flux collecting part 15c, but the present invention is not limited to this.
  • the magnetic flux collection unit 15c may be disposed at a position that includes the pair of reflectors 41a and 41b on the projection surface that is projected in the thickness direction of the piezoelectric substrate 11. Further, the pair of reflectors 41a and 41b may be arranged on one main surface 11a of the piezoelectric substrate 11 and below the magnetic flux collecting portion 15c.
  • the pair of reflectors 51a and 51b are attached to both sides of the magnetic flux collecting part 36c, but are not limited thereto.
  • the magnetic flux collecting portion 36c may be arranged at a position including the pair of reflectors 51a and 51b on the projection surface projected in the thickness direction of the piezoelectric substrate 11. Further, the pair of reflectors 51a and 51b may be arranged on one main surface 11a of the piezoelectric substrate 11 and below the magnetic flux collecting portion 36c. Further, in FIG. 7, the reflector 61 is attached to one side of the magnetic flux collecting portion 15c, but is not limited thereto.
  • the magnetic flux collecting portion 15c is arranged at a position including the one reflector 61 on a projection plane projected in the thickness direction of the piezoelectric substrate 11, and the one reflector 61 is disposed on one main surface 11a of the piezoelectric substrate 11. Therefore, it may be arranged below the magnetic flux collecting portion 15c.
  • the elastic wave modulation element of the present invention can be applied to various physical quantity sensors for magnetic field, torque, pressure, temperature and the like.

Abstract

Provided are an acoustic wave modulation element and physical quantity sensor that make it possible to enhance sensitivity compared to the prior art and accurately detect a physical quantity of an object to be detected. This acoustic wave modulation element (10) comprises a piezoelectric substrate (11), a first electrode unit (12) that is attached to the piezoelectric substrate (11) and causes the piezoelectric substrate (11) to generate an acoustic wave, a second electrode unit (13) that is attached to the piezoelectric substrate (11) and receives the acoustic wave, and a magnetostrictive material part (15) that is provided in or near the area of the acoustic wave. The magnetostrictive material part (15) comprises a pair of magnetic flux propagation parts (15a, 15b) that are provided on one main surface (11a) of the piezoelectric substrate (11) and are capable of propagating the magnetic flux of an external magnetic field and a magnetic-flux-concentration part (15c) that is provided on the one main surface (11a) between the pair of magnetic flux propagation parts (15a, 15b) and is disposed on or near the propagation route (14) of the acoustic wave.

Description

弾性波変調素子及び物理量センサElastic wave modulator and physical quantity sensor
　本発明は、弾性波変調素子及び物理量センサに関し、特に、表面弾性波の伝搬特性の変化に基づいて被検出体の物理量を検出可能な弾性波変調素子に関する。 The present invention relates to an elastic wave modulating element and a physical quantity sensor, and more particularly to an elastic wave modulating element capable of detecting a physical quantity of an object to be detected based on a change in propagation characteristics of a surface acoustic wave.
　従来、表面弾性波（以下、ＳＡＷ（Ｓｕｆａｃｅ Ａｃｏｕｓｔｉｃ Ｗａｖｅ）ともいう）を用いた遅延線型や共振子型のセンサがある。遅延線型のＳＡＷセンサの構成として、例えば、ＬｉＮｂＯ３基板と、該基板上に設けられた一対の櫛歯電極部と、該一対の櫛歯電極部間のＳＡＷ伝搬領域に配置された非晶質ＴｂＦｅ２膜とを備えるＳＡＷ遅延線が提案されている（非特許文献１）。 Conventionally, there is a delay line type or resonator type sensor using a surface acoustic wave (hereinafter also referred to as SAW (Surface Acoustic Wave)). As a configuration of the delay line type SAW sensor, for example, a LiNbO3 substrate, a pair of comb electrode portions provided on the substrate, and an amorphous TbFe2 disposed in a SAW propagation region between the pair of comb electrode portions. A SAW delay line including a film has been proposed (Non-Patent Document 1).
　また、遅延線型のＳＡＷセンサとして、圧電基板と櫛歯電極を有する表面弾性波素子とアンテナ手段を備えた応答器と、上記応答器に対して駆動信号を発信すると共に、当該応答器からの応答信号を受信する問い合わせ器とからなるワイヤレスＳＡＷセンサが提案されている。このＳＡＷセンサは、表面弾性波の伝搬方向と一致する辺を有する略矩形状をなし、かつ上記櫛歯電極から離間している磁歪膜を備えており、矩形磁歪膜における櫛歯電極側端部からの反射波に対応するエコーと、この矩形磁歪膜における反櫛歯電極側端部からの反射波に対応するエコーとの時間差に基づいて圧電基板に働く応力を検出している（特許文献１）。 Further, as a delay line type SAW sensor, a transponder including a surface acoustic wave element having a piezoelectric substrate and a comb electrode and an antenna means, a drive signal is transmitted to the transponder, and a response from the transponder is provided. A wireless SAW sensor including an interrogator for receiving a signal has been proposed. This SAW sensor has a magnetostrictive film having a substantially rectangular shape having sides coinciding with the propagation direction of the surface acoustic wave, and having a magnetostrictive film separated from the comb-teeth electrode. The stress acting on the piezoelectric substrate is detected based on the time difference between the echo corresponding to the reflected wave from the substrate and the echo corresponding to the reflected wave from the anti-comb electrode side end of the rectangular magnetostrictive film (Patent Document 1). ).
　この従来技術では、圧電基板に応力が作用することより磁歪膜にも応力が作用すると、磁歪膜における磁化状態が変わり、その結果として磁歪膜と圧電基板の弾性率が変化するΔＥ効果が生じる。このΔＥ効果によって、磁歪膜と圧電基板を伝搬する表面弾性波の速度が変化する。よって、上記エコーの時間差を、圧電基板に作用する応力に対して予め校正しておくことで、当該時間差から、圧電基板に働く応力（歪）が計測することができるとされている。 According to this conventional technique, when stress acts on the magnetostrictive film due to stress acting on the piezoelectric substrate, the magnetization state in the magnetostrictive film changes, and as a result, the ΔE effect occurs in which the elastic modulus of the magnetostrictive film and the piezoelectric substrate changes. Due to the ΔE effect, the velocity of the surface acoustic wave propagating through the magnetostrictive film and the piezoelectric substrate changes. Therefore, by calibrating the time difference of the echo with respect to the stress acting on the piezoelectric substrate in advance, the stress (strain) acting on the piezoelectric substrate can be measured from the time difference.
特許第５０８７９６４号公報Japanese Patent No. 5087964
　しかしながら、磁歪膜のいわゆるΔＥ効果は、磁歪膜における磁化状態の変化に依存するため、磁化状態の変化量が小さいとΔＥ効果が生じ難い。よって、圧電基板に働く応力が小さいと、圧電基板に働く応力を十分に検知できず、感度が良好でない場合がある。または、磁歪膜に印加された外部磁界（磁場）が小さい場合は、外部磁界による磁化状態の変化量が小さいためΔＥ効果も小さくなり、センサとしての磁界感度が良好でない場合がある。 However, since the so-called ΔE effect of the magnetostrictive film depends on the change in the magnetization state in the magnetostrictive film, the ΔE effect hardly occurs when the amount of change in the magnetization state is small. Therefore, when the stress acting on the piezoelectric substrate is small, the stress acting on the piezoelectric substrate cannot be sufficiently detected, and the sensitivity may not be good. Alternatively, when the external magnetic field (magnetic field) applied to the magnetostrictive film is small, the change in the magnetization state due to the external magnetic field is small, so that the ΔE effect is also small, and the magnetic field sensitivity as a sensor may not be good.
　本発明の目的は、従来よりも感度を向上して被検出体の物理量を精度良く検知することができる弾性波変調素子及び物理量センサを提供することにある。 An object of the present invention is to provide an elastic wave modulation element and a physical quantity sensor capable of detecting a physical quantity of an object to be detected with improved sensitivity compared to the related art.
　上記目的を達成するために、本発明は以下の手段を提供する。
［１］圧電基板と、
　前記圧電基板に取り付けられ、前記圧電基板に弾性波を励起する第１電極部と、
　前記圧電基板に取り付けられ、前記弾性波を受信する第２電極部と、
　前記弾性波の存在領域またはその近傍に設けられた磁歪材料部と、
　を備え、
　前記磁歪材料部は、
　前記圧電基板の一方の主面上に設けられ、外部磁界の磁束を伝搬可能な一対の磁束伝搬部と、
　前記一方の主面上において前記一対の磁束伝搬部の間に設けられ、前記弾性波の伝搬路上またはその近傍に配置された集磁部と、
　を有する、
　ことを特徴とする弾性波変調素子。
［２］前記一対の磁束伝搬部の各々は、前記集磁部とは反対側の一端部から前記集磁部側の他端部に向かう方向に沿って断面積が小さくなる形状を有し、
　前記集磁部の磁場方向に垂直な断面積の最小値が、前記一対の磁束伝搬部の前記断面積の最小値と同じかそれよりも小さい、上記［１］記載の弾性波変調素子。
［３］前記集磁部は、前記圧電基板の厚み方向の投影面において、前記第１電極部と第２電極部との間に配置される、上記［１］または［２］に記載の弾性波変調素子。
［４］前記集磁部における磁束が、前記弾性波の伝搬方向に垂直な方向に沿って形成され、
　前記一対の磁束伝搬部及び前記集磁部は、前記圧電基板の一方の主面上に配置され、
　前記第１電極部及び前記第２電極部は、前記圧電基板の前記一方の主面上に配置されるか、または前記圧電基板の他方の主面上に配置される、上記［３］に記載の弾性波変調素子。
［５］前記集磁部における磁束が、前記弾性波の伝搬方向に沿って形成され、
　前記一対の磁束伝搬部及び前記集磁部は、前記圧電基板の一方の主面上に配置され、
　前記第１電極部及び前記第２電極部は、前記一方の主面上であって前記一対の磁束伝搬部に設けられた一対の開口部に対応する位置に配置されるか、前記一方の主面上であって前記一対の磁束伝搬部の下に配置されるか、または、前記圧電基板の他方の主面上に配置される、上記［３］に記載の弾性波変調素子。
［６］前記集磁部は、前記圧電基板の厚み方向に投影した投影面において、前記第１電極部及び前記第２電極部を包含する位置に配置される、上記［１］または［２］に記載の弾性波変調素子。
［７］前記集磁部における磁束が、前記弾性波の伝搬方向に垂直な方向に沿って形成され、
　前記一対の磁束伝搬部及び前記集磁部は、前記圧電基板の一方の主面上に配置され、
　前記第１電極部及び前記第２電極部が、前記圧電基板の前記一方の主面上であって前記集磁部の下に配置されるか、または前記圧電基板の他方の主面上に配置される、上記［６］に記載の弾性波変調素子。
［８］前記集磁部における磁束が、前記弾性波の伝搬方向に沿って形成され、
　前記一対の磁束伝搬部及び前記集磁部は、前記圧電基板の一方の主面上に配置され、
　前記第１電極部及び前記第２電極部が、前記圧電基板の前記一方の主面上であって前記集磁部の下に配置されるか、または、前記圧電基板の他方の主面上に配置される、上記［６］に記載の弾性波変調素子。
［９］前記第１電極部が、互いの歯が交互に並ぶように対向して配置された一対の櫛歯電極で構成され、
　前記第２電極部が、互いの歯が交互に並ぶように対向して配置された他の一対の櫛歯電極で構成される、上記［１］～［８］のいずれかに記載の弾性波変調素子。
［１０］前記第１電極部および前記第２電極部が、前記圧電基板に弾性波を励起または受信する一対の櫛歯電極である、上記［１］～［８］のいずれかに記載の弾性波変調素子。
［１１］前記圧電基板に取り付けられ、前記集磁部の一方側に配置された一の反射器を更に備え、
　前記第１電極部及び前記第２電極部が、前記圧電基板の一方の主面上であって前記集磁部の他方側に配置されるか、または前記圧電基板の一方の主面上であって前記集磁部の下に配置される、上記［１］～［１０］のいずれかに記載の弾性波変調素子。
［１２］前記集磁部は、前記圧電基板の厚み方向に投影した投影面において、前記一の反射器を包含する位置に配置され、前記一の反射器が、圧電基板の前記一方の主面上であって前記集磁部の下に配置される、上記［１１］に記載の弾性波変調素子。
［１３］前記圧電基板に取り付けられ、前記第１電極部及び前記第２電極部の両側に配置された一対の反射器を更に備える、上記［１］～［１０］のいずれか１項に記載の弾性波変調素子。
［１４］前記集磁部は、前記圧電基板の厚み方向に投影した投影面において、前記一対の反射器を包含する位置に配置され、前記一対の反射器が、圧電基板の前記一方の主面上であって前記集磁部の下に配置される、上記［１３］に記載の弾性波変調素子。
［１５］上記［１］～［１４］のいずれかに記載の弾性波変調素子と、前記弾性波変調素子の変調を検出する回路部と、を備える物理量センサ。 In order to achieve the above object, the present invention provides the following means.
[1] a piezoelectric substrate;
A first electrode unit attached to the piezoelectric substrate and exciting an elastic wave to the piezoelectric substrate;
A second electrode unit attached to the piezoelectric substrate and receiving the elastic wave;
Magnetostrictive material portion provided in or near the elastic wave existence region,
With
The magnetostrictive material section includes:
A pair of magnetic flux transmission units provided on one main surface of the piezoelectric substrate and capable of transmitting a magnetic flux of an external magnetic field,
A magnetic flux collection unit provided between the pair of magnetic flux transmission units on the one main surface, and disposed on or near the elastic wave propagation path;
Having,
An elastic wave modulating element characterized by the above-mentioned.
[2] Each of the pair of magnetic flux propagation sections has a shape in which a cross-sectional area decreases along a direction from one end on the side opposite to the magnetic flux collection section to the other end on the magnetic flux collection section side,
The elastic wave modulator according to [1], wherein a minimum value of a cross-sectional area of the magnetic flux collection unit perpendicular to a magnetic field direction is equal to or smaller than a minimum value of the cross-sectional area of the pair of magnetic flux transmission units.
[3] The elasticity according to [1] or [2], wherein the magnetic flux collecting unit is disposed between the first electrode unit and the second electrode unit on a projection plane in a thickness direction of the piezoelectric substrate. Wave modulation element.
[4] a magnetic flux in the magnetic flux collecting unit is formed along a direction perpendicular to a propagation direction of the elastic wave;
The pair of magnetic flux transmission units and the magnetic flux collection unit are disposed on one main surface of the piezoelectric substrate,
The above-mentioned [3], wherein the first electrode portion and the second electrode portion are arranged on the one main surface of the piezoelectric substrate or are arranged on the other main surface of the piezoelectric substrate. Elastic wave modulator.
[5] a magnetic flux in the magnetic flux collecting unit is formed along a propagation direction of the elastic wave;
The pair of magnetic flux transmission units and the magnetic flux collection unit are disposed on one main surface of the piezoelectric substrate,
The first electrode portion and the second electrode portion are disposed on the one main surface at positions corresponding to a pair of openings provided in the pair of magnetic flux transmission portions, or The elastic wave modulating element according to the above [3], which is arranged on a surface and below the pair of magnetic flux propagation parts, or arranged on the other main surface of the piezoelectric substrate.
[6] The above [1] or [2], wherein the magnetic flux collecting unit is arranged at a position including the first electrode unit and the second electrode unit on a projection plane projected in the thickness direction of the piezoelectric substrate. 3. The elastic wave modulation device according to claim 1.
[7] The magnetic flux in the magnetic flux collection unit is formed along a direction perpendicular to the propagation direction of the elastic wave,
The pair of magnetic flux transmission units and the magnetic flux collection unit are disposed on one main surface of the piezoelectric substrate,
The first electrode portion and the second electrode portion are disposed on the one main surface of the piezoelectric substrate and below the magnetic flux collecting portion, or disposed on the other main surface of the piezoelectric substrate. The elastic wave modulation element according to the above [6].
[8] The magnetic flux in the magnetic flux collecting unit is formed along the propagation direction of the elastic wave,
The pair of magnetic flux transmission units and the magnetic flux collection unit are disposed on one main surface of the piezoelectric substrate,
The first electrode portion and the second electrode portion are disposed on the one main surface of the piezoelectric substrate and below the magnetic flux collecting portion, or on the other main surface of the piezoelectric substrate. The elastic wave modulation device according to the above [6], which is arranged.
[9] The first electrode portion is constituted by a pair of comb-tooth electrodes arranged so as to face each other so that the teeth are alternately arranged,
The elastic wave according to any one of [1] to [8], wherein the second electrode unit includes another pair of comb-shaped electrodes arranged so as to face each other so that the teeth are alternately arranged. Modulation element.
[10] The elasticity according to any of [1] to [8], wherein the first electrode portion and the second electrode portion are a pair of comb-shaped electrodes for exciting or receiving an elastic wave to the piezoelectric substrate. Wave modulation element.
[11] One further reflector attached to the piezoelectric substrate and disposed on one side of the magnetic flux collecting part,
The first electrode portion and the second electrode portion are disposed on one main surface of the piezoelectric substrate and on the other side of the magnetic flux collecting portion, or on one main surface of the piezoelectric substrate. The elastic wave modulator according to any one of [1] to [10], which is arranged below the magnetic flux collecting part.
[12] The magnetic flux collection unit is disposed at a position including the one reflector on a projection plane projected in the thickness direction of the piezoelectric substrate, and the one reflector is provided on the one main surface of the piezoelectric substrate. The elastic wave modulating element according to the above [11], which is arranged above and below the magnetic flux collecting part.
[13] The device according to any one of [1] to [10], further including a pair of reflectors attached to the piezoelectric substrate and arranged on both sides of the first electrode portion and the second electrode portion. Elastic wave modulator.
[14] The magnetic flux collecting portion is disposed at a position including the pair of reflectors on a projection plane projected in a thickness direction of the piezoelectric substrate, and the pair of reflectors is disposed on the one main surface of the piezoelectric substrate. The elastic wave modulating element according to the above [13], which is arranged above and below the magnetic flux collecting part.
[15] A physical quantity sensor comprising: the elastic wave modulation element according to any one of [1] to [14]; and a circuit unit that detects modulation of the elastic wave modulation element.
　本発明によれば、従来よりも感度を向上して被検出体の物理量を精度良く検知することができる。 According to the present invention, it is possible to detect a physical quantity of an object to be detected with high accuracy and a physical quantity of an object to be detected with higher accuracy than before.
本発明の第１実施形態に係る弾性波変調素子を備える物理量センサの構成を概略的に示す図であり、（ａ）は平面図、（ｂ）は線Ｉ－Ｉに沿う断面図、（ｃ）は底面図である。It is a figure showing roughly composition of a physical quantity sensor provided with an elastic wave modulation element concerning a 1st embodiment of the present invention, (a) is a top view, (b) is a sectional view which meets a line II, (c) ) Is a bottom view. 本発明の第２実施形態に係る弾性波変調素子を備える物理量センサの変形例を示す図であり、（ａ）は平面図、（ｂ）は線ＩＩ－ＩＩに沿う断面図、（ｃ）は底面図である。It is a figure which shows the modification of the physical quantity sensor provided with the elastic wave modulation element which concerns on 2nd Embodiment of this invention, (a) is a top view, (b) is sectional drawing which follows the line II-II, (c) is It is a bottom view. （ａ）は、図１における弾性波変調素子の第１変形例を示す図であり、（ｂ）は、第２変形例を示す図である。(A) is a figure which shows the 1st modification of the elastic wave modulation element in FIG. 1, (b) is a figure which shows the 2nd modification. 図１における弾性波変調素子の第３変形例を示す図であり、（ａ）は平面図、（ｂ）は線ＩＩＩ－ＩＩＩに沿う断面図である。FIG. 3 is a diagram showing a third modification of the elastic wave modulation element in FIG. 1, where (a) is a plan view and (b) is a cross-sectional view along line III-III. 本発明の第３実施形態に係る弾性波変調素子の構成を概略的に示す図であり、（ａ）は平面図、（ｂ）は線ＩＶ－ＩＶに沿う断面図である。It is a figure which shows roughly the structure of the elastic wave modulation element which concerns on 3rd Embodiment of this invention, (a) is a top view, (b) is sectional drawing which follows the line IV-IV. （ａ）は、本発明の第４実施形態に係る弾性波変調素子を備える物理量センサの構成を概略的に示す平面図であり、（ｂ）は、第４実施形態の変形例を示す平面図である。(A) is a top view which shows roughly the structure of the physical quantity sensor provided with the elastic wave modulation element which concerns on 4th Embodiment of this invention, (b) is a top view which shows the modification of 4th Embodiment. It is. 本発明の第５実施形態に係る弾性波変調素子を備える物理量センサの構成を概略的に示す平面図である。It is a top view showing roughly composition of a physical quantity sensor provided with an elastic wave modulation element concerning a 5th embodiment of the present invention.
　以下、本発明の実施形態について、図面を参照して詳細に説明する。
［弾性波変調素子及び物理量センサの構成］
　図１は、本発明の第１実施形態に係る弾性波変調素子を備える物理量センサの構成を概略的に示す図であり、（ａ）は平面図、（ｂ）は線Ｉ－Ｉに沿う断面図、（ｃ）は底面図である。本実施形態では、物理量センサが遅延線型である場合を例に挙げて説明する。なお、以下の説明で用いる図面は、特徴をわかりやすくするために、便宜上特徴となる部分を拡大して示している場合があり、各構成要素の寸法比率等は図示するものに限らないものとする。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[Configuration of elastic wave modulation element and physical quantity sensor]
FIGS. 1A and 1B are diagrams schematically showing a configuration of a physical quantity sensor including an elastic wave modulation element according to a first embodiment of the present invention, wherein FIG. 1A is a plan view, and FIG. 1B is a cross-section along line II. FIG. 3C is a bottom view. In the present embodiment, a case where the physical quantity sensor is a delay line type will be described as an example. In the drawings used in the following description, in order to make the characteristics easy to understand, the characteristic portions may be enlarged for convenience, and the dimensional ratios and the like of the respective components are not limited to those illustrated. I do.
　図１（ａ）～図１（ｃ）に示すように、弾性波変調素子１０は、圧電基板１１と、圧電基板１１に取り付けられ、圧電基板１１に弾性波を励起する第１電極部１２と、圧電基板１１に取り付けられ、弾性波を受信する第２電極部１３と、弾性波の存在領域また はその近傍に設けられた磁歪材料部１５とを備える。弾性波変調素子１０は、該弾性波変調素子１０からの信号に基づいて弾性波の変調を検出する不図示の検出回路部に接続されており、弾性波変調素子１０及び上記検出回路部が物理量センサ１を構成する。すなわち、物理量センサ１は、弾性波変調素子１０及び上記検出回路部を備えており、弾性波の伝搬特性の変化に基づいて被検出体の物理量を検出する。また、物理量センサ１は、圧電基板１１上の磁歪材料部１５に磁界を印加する磁界印加部１６を備えており、磁界印加部１６が磁歪材料部１５内に磁界を印加することで、磁歪材料部１５内に磁界（磁場）が形成される。物理量センサ１は、例えば、圧力センサや、磁気センサなどである。 As shown in FIGS. 1A to 1C, the elastic wave modulating element 10 includes a piezoelectric substrate 11, a first electrode unit 12 attached to the piezoelectric substrate 11, and exciting the piezoelectric substrate 11 with an elastic wave. A second electrode portion 13 attached to the piezoelectric substrate 11 for receiving an elastic wave, and a magnetostrictive material portion 15 provided in or near the elastic wave existing region. The elastic wave modulation element 10 is connected to a detection circuit (not shown) that detects the modulation of the elastic wave based on a signal from the elastic wave modulation element 10. The sensor 1 is configured. That is, the physical quantity sensor 1 includes the elastic wave modulation element 10 and the detection circuit unit, and detects the physical quantity of the detection target based on a change in the propagation characteristic of the elastic wave. Further, the physical quantity sensor 1 includes a magnetic field applying unit 16 that applies a magnetic field to the magnetostrictive material unit 15 on the piezoelectric substrate 11. A magnetic field (magnetic field) is formed in the portion 15. The physical quantity sensor 1 is, for example, a pressure sensor, a magnetic sensor, or the like.
　圧電基板１１は、ＳｉＯ２、ＬｉＮｂＯ３、ＬｉＴａＯ３、ＢａＴｉＯ３、ＰｂＴｉＯ３、Ｐｂ（Ｚｒ・Ｔｉ）Ｏ３（チタン酸ジルコン酸鉛）、Ｌａ３Ｇａ５ＳｉＯ１４、Ｌｉ２Ｂ４Ｏ７、ＡｌＮ（窒化アルミニウム）、ＺｎＯおよびダイヤモンドからなる群から選択される少なくとも１つの材料で構成される。圧電基板１１が上記群から選択される少なくとも１つの材料で構成されることにより、圧電基板１１において弾性波を効率的に発生させることができる。 The piezoelectric substrate 11 is selected from the group consisting of SiO2, LiNbO3, LiTaO3, BaTiO3, PbTiO3, Pb (Zr.Ti) O3 (lead zirconate titanate), La3Ga5SiO14, Li2B4O7, AlN (aluminum nitride), ZnO and diamond. It is composed of at least one material. Since the piezoelectric substrate 11 is made of at least one material selected from the above group, it is possible to efficiently generate an elastic wave in the piezoelectric substrate 11.
　第１電極部１２は、例えば互いの歯が交互に並ぶように対向して配置された一対の櫛歯電極１２ａ，１２ｂで構成されている（図１（ａ））。この第１電極部１２は、入力部１７からの入力信号に基づいて弾性波、特に表面弾性波（ＳＡＷ）を発生させる入力電極に相当する。第１電極部１２を構成する一対の櫛歯電極１２ａ，１２ｂの歯のピッチは、任意に設定可能であるが、例えばλ／４（λはＳＡＷの波長）で一定である。 The first electrode section 12 is composed of, for example, a pair of comb- tooth electrodes 12a and 12b opposed to each other so that the teeth are alternately arranged (FIG. 1A). The first electrode unit 12 corresponds to an input electrode that generates an elastic wave, particularly a surface acoustic wave (SAW) based on an input signal from the input unit 17. The pitch of the teeth of the pair of comb electrodes 12a and 12b constituting the first electrode unit 12 can be set arbitrarily, but is constant at, for example, λ / 4 (λ is the wavelength of the SAW).
　また、第２電極部１３は、例えば互いの歯が交互に並ぶように対向して配置された一対の櫛歯電極１３ａ，１３ｂ（他の一対の櫛歯電極）で構成されている（図１（ａ））。この第２電極部１３は、弾性波、特にＳＡＷを受信して、該弾性波に対応する出力信号を出力部１８を介して上記検出回路部に出力する出力電極に相当する。第２電極部１３を構成する一対の櫛歯電極１３ａ，１３ｂの歯のピッチも、任意に設定可能であるが、例えば一対の櫛歯電極１２ａ，１２ｂの歯のピッチと同じである。 The second electrode section 13 is composed of, for example, a pair of comb- tooth electrodes 13a and 13b (another pair of comb-tooth electrodes) arranged to face each other such that the teeth are alternately arranged (FIG. 1). (A)). The second electrode unit 13 corresponds to an output electrode that receives an elastic wave, particularly SAW, and outputs an output signal corresponding to the elastic wave to the detection circuit unit via the output unit 18. The pitch of the teeth of the pair of comb electrodes 13a and 13b constituting the second electrode unit 13 can be arbitrarily set, but is, for example, the same as the pitch of the teeth of the pair of comb electrodes 12a and 12b.
　第１電極部１２及び第２電極部１３は、電極材料として適していればその材料に特に制限はないが、例えばＡｌ（アルミニウム）、Ａｕ（金）、Ｃｕ（銅）、Ｔｉ（チタン）、Ｃｒ（クロム）、あるいはこれらの合金などの材料で構成される。 The first electrode section 12 and the second electrode section 13 are not particularly limited as long as they are suitable as electrode materials. For example, Al (aluminum), Au (gold), Cu (copper), Ti (titanium), It is composed of a material such as Cr (chromium) or an alloy thereof.
　磁歪材料部１５は、圧電基板１１の一方の主面１１ａ上に設けられ、外部磁界の磁束を伝搬可能な一対の磁束伝搬部１５ａ，１５ｂと、一方の主面１１ａ上において一対の磁束伝搬部１５ａ，１５ｂの間に設けられ、弾性波の伝搬路１４上に配置された集磁部１５ｃとを有する。本実施形態では、集磁部１５ｃは、一対の磁束伝搬部１５ａ，１５ｂと一体で形成されている。 The magnetostrictive material portion 15 is provided on one main surface 11a of the piezoelectric substrate 11 and is capable of transmitting a magnetic flux of an external magnetic field, and a pair of magnetic flux transmitting portions on the one main surface 11a. And a magnetic flux collector 15c provided between the elastic wave propagation paths 14 and 15a and 15b. In the present embodiment, the magnetic flux collecting portion 15c is formed integrally with the pair of magnetic flux transmitting portions 15a and 15b.
　一対の磁束伝搬部１５ａ，１５ｂの各々は、集磁部１５ｃとは反対側の一端部から集磁部１５ｃ側の他端部に向かう方向に沿って断面積が小さくなる形状を有しているのが好ましい。また、集磁部１５ｃの磁場方向に垂直な断面積の最小値が、一対の磁束伝搬部１５ａ，１５ｂの断面積の最小値と同じかそれよりも小さいのが好ましい。本実施形態では、物理量センサ１の平面視において、一対の磁束伝搬部１５ａ，１５ｂが扁平の台形状を有し、集磁部１５ｃが矩形状を有している（図１（ａ））。
　このように、磁歪材料部１５がくびれ形状を有し、幅広な一対の磁束伝搬部１５ａ，１５ｂの間に幅狭な集磁部１５ｃが配置されることで、磁歪材料部１５に磁界が印加されたときに集磁部１５ｃで確実に集磁することができる。 Each of the pair of magnetic flux transmitting portions 15a and 15b has a shape in which the cross-sectional area decreases along a direction from one end opposite to the magnetic flux collecting portion 15c toward the other end of the magnetic flux collecting portion 15c. Is preferred. Further, it is preferable that the minimum value of the cross-sectional area of the magnetic flux collection unit 15c perpendicular to the magnetic field direction is equal to or smaller than the minimum value of the cross-sectional area of the pair of magnetic flux transmission units 15a and 15b. In the present embodiment, in a plan view of the physical quantity sensor 1, the pair of magnetic flux transmitting portions 15a and 15b have a flat trapezoidal shape, and the magnetic flux collecting portion 15c has a rectangular shape (FIG. 1A).
As described above, since the magnetostrictive material portion 15 has a constricted shape and the narrow magnetic flux collecting portion 15c is arranged between the pair of wide magnetic flux transmitting portions 15a and 15b, a magnetic field is applied to the magnetostrictive material portion 15. Then, the magnetic flux can be reliably collected by the magnetic flux collecting unit 15c.
　集磁部１５ｃは、例えば圧電基板１１の厚み方向の投影面において、第１電極部１２と第２電極部１３との間に配置される（図１（ａ），（ｃ）参照）。本実施形態では、集磁部１５ｃにおける磁束が、弾性波の伝搬方向に垂直な方向に沿って形成される。この場合において、一対の磁束伝搬部１５ａ，１５ｂ及び集磁部１５ｃは、圧電基板１１の一方の主面１１ａ上に配置され、第１電極部１２及び第２電極部１３も、圧電基板１１の一方の主面１１ａ上に配置されている。本構成によれば、磁歪材料部１５が、弾性波が伝搬する圧電基板１１の一方の主面１１ａに当接して配置されるので、伝搬路１４である一方の主面１１ａあるいはその近傍で、磁歪による弾性波の伝搬速度の変化をより増大させることができる。 (4) The magnetic flux collection unit 15c is disposed between the first electrode unit 12 and the second electrode unit 13 on the projection plane in the thickness direction of the piezoelectric substrate 11, for example (see FIGS. 1A and 1C). In the present embodiment, the magnetic flux in the magnetic flux collecting portion 15c is formed along a direction perpendicular to the propagation direction of the elastic wave. In this case, the pair of magnetic flux transmitting parts 15a, 15b and the magnetic flux collecting part 15c are arranged on one main surface 11a of the piezoelectric substrate 11, and the first electrode part 12 and the second electrode part 13 It is arranged on one main surface 11a. According to this configuration, since the magnetostrictive material portion 15 is arranged in contact with the one main surface 11a of the piezoelectric substrate 11 through which the elastic wave propagates, The change in the propagation speed of the elastic wave due to the magnetostriction can be further increased.
　磁歪材料部１５は、Ｃｏ、Ｎｉ、Ｆｅ、ＣｏＮｉ、ＮｉＦｅ、ＣｏＦｅ、ＦｅＡｌ、ＣｏＰｔ、ＮｉＣｏＣｒ、ＦｅＢ、ＣｏＦｅＢ、ＣｏＦｅＳｉＢ、ＦｅＢＳｉＰ、ＦｅＢＳｉＣ、Ｎｉ２ＭｎＧａ、ＦｅＣｏＮｉＢＳｉ、ＴｂＦｅＣｏ、Ｃｏフェライト、Ｎｉフェライト、Ｃｕフェライト、Ｌｉフェライト、Ｍｎフェライト、ＮｉＣｏフェライト、ＮｉＣｕＣｏフェライト、Ｆｅ３О４、ＴｂＦｅ２、ＤｙＦｅ２、ＥｒＦｅ２、ＴｍＦｅ２、ＳｍＦｅ２、ＧａＦｅ、Ｔｂ（０．２７～０．３原子組成比率）、Ｄｙ（０．７～０．７３原子組成比率）、Ｆｅ（１．９～２．０原子組成比率）からなる群から選択される少なくとも１つの材料で構成される。磁歪材料部１５が上記群から選択される少なくとも１つの材料で構成されることにより、磁歪材料部１５において磁歪を効率的に発生させることができる。 The magnetostrictive material portion 15 includes Co, Ni, Fe, CoNi, NiFe, CoFe, FeAl, CoPt, NiCoCr, FeB, CoFeB, CoFeSiB, FeBSiP, FeBSiC, Ni2MnGa, FeCoNiBSi, TbFeCo, Co ferrite, Ni ferrite, Cu ferrite, and Li. Ferrite, Mn ferrite, NiCo ferrite, NiCuCo ferrite, Fe3О4, TbFe2, DyFe2, ErFe2, TmFe2, SmFe2, GaFe, Tb (0.27 to 0.3 atomic composition ratio), Dy (0.7 to 0.73 atomic composition) And at least one material selected from the group consisting of Fe (1.9 to 2.0 atomic composition ratio). Since the magnetostrictive material 15 is made of at least one material selected from the above group, magnetostriction can be efficiently generated in the magnetostrictive material 15.
　磁歪材料部１５は、例えば磁歪膜で形成されており、その場合、一対の磁束伝搬部１５ａ，１５ｂ及び集磁部１５ｃも磁歪膜で形成される。磁歪材料部１５の厚さは１０ｎｍ～１０μｍである。磁歪材料部１５の形成方法には制限はないが、例えばマグネトロンスパッタリングなどのスパッタリングによって成膜することができる。 (4) The magnetostrictive material portion 15 is formed of, for example, a magnetostrictive film. In this case, the pair of magnetic flux transmitting portions 15a and 15b and the magnetic flux collecting portion 15c are also formed of the magnetostrictive film. The thickness of the magnetostrictive material portion 15 is 10 nm to 10 μm. The method of forming the magnetostrictive material portion 15 is not limited, but it can be formed by sputtering such as magnetron sputtering.
　磁界印加部１６は、磁歪材料部１５に磁歪を生じさせるための磁界を磁歪材料部１５に印加する。磁歪材料部１５に印加される磁界（磁場）は、磁歪効果が得られる静磁場であるのが好ましいが、変動磁場であってもよい。磁歪材料部１５に印加される磁界（磁場）が静磁場である場合、磁界印加部１６は、例えば永久磁石で構成される。磁界印加部１６により、磁化状態を最適な動作原点とするためのバイアス磁界を与えることができる。また、磁歪材料部１５の磁界印加部１６とは反対側に、他の磁界印加部が設けられるのが好ましい。 (4) The magnetic field applying unit 16 applies a magnetic field to the magnetostrictive material unit 15 to cause the magnetostrictive material unit 15 to generate magnetostriction. The magnetic field (magnetic field) applied to the magnetostrictive material portion 15 is preferably a static magnetic field capable of obtaining a magnetostrictive effect, but may be a fluctuating magnetic field. When the magnetic field (magnetic field) applied to the magnetostrictive material section 15 is a static magnetic field, the magnetic field applying section 16 is configured by, for example, a permanent magnet. The magnetic field applying unit 16 can apply a bias magnetic field for setting the magnetization state to an optimum operation origin. Further, it is preferable that another magnetic field applying unit is provided on the side of the magnetostrictive material unit 15 opposite to the magnetic field applying unit 16.
［弾性波変調素子及び物理量センサの動作］
　上記のように構成される弾性波変調素子１０では、先ず、入力信号が第１電極部１２に入力されて一対の櫛歯電極１２ａ，１２ｂ間に電位差が生じると、一対の櫛歯電極１２ａ，１２ｂを介して圧電基板１１に電位差が生じる。これにより、圧電基板１１の表面のうち、第１電極部１２が形成された部分で圧電効果によるＳＡＷが発生する。 [Operation of elastic wave modulation element and physical quantity sensor]
In the elastic wave modulation element 10 configured as described above, first, when an input signal is input to the first electrode unit 12 and a potential difference is generated between the pair of comb electrodes 12a and 12b, the pair of comb electrodes 12a and 12b A potential difference is generated in the piezoelectric substrate 11 via 12b. As a result, SAW due to the piezoelectric effect is generated in a portion of the surface of the piezoelectric substrate 11 where the first electrode portion 12 is formed.
　次に、圧電基板１１が、例えば表面弾性波のうちのＳＨ波（以下、ＳＨ－ＳＡＷともいう）を生じさせる構成である場合、ＳＨ－ＳＡＷは圧電基板１１の主面１１ａ或いはその近傍のうち、第１電極部１２と第２電極部１３の間の伝搬路１４を伝搬して、第２電極部１３に到達する。このとき、圧電基板１１に応力が生じて、磁歪材料部１５にも応力が作用すると、磁歪材料部１５の磁化状態が変わり、その結果として磁歪材料部１５、特に集磁部１５ｃの弾性率が変わり（ΔＥ効果）、これにより、伝搬路１４を伝搬するＳＨ－ＳＡＷの伝搬速度が変わる。あるいは、磁歪材料部１５に外部磁界が印加されると、ΔＥ効果により伝搬路１４を伝搬するＳＨ－ＳＡＷの伝搬速度が変わる。 Next, when the piezoelectric substrate 11 is configured to generate, for example, an SH wave (hereinafter, also referred to as SH-SAW) of the surface acoustic wave, the SH-SAW is generated on the main surface 11a of the piezoelectric substrate 11 or in the vicinity thereof. The light propagates through the propagation path 14 between the first electrode unit 12 and the second electrode unit 13 and reaches the second electrode unit 13. At this time, when a stress is applied to the piezoelectric substrate 11 and the stress also acts on the magnetostrictive material portion 15, the magnetization state of the magnetostrictive material portion 15 changes, and as a result, the elastic modulus of the magnetostrictive material portion 15, particularly the magnetic flux collecting portion 15c is reduced. Change (ΔE effect), whereby the propagation speed of the SH-SAW propagating in the propagation path 14 changes. Alternatively, when an external magnetic field is applied to the magnetostrictive material portion 15, the propagation speed of the SH-SAW propagating through the propagation path changes due to the ΔE effect.
　ここで、上述のように、磁歪材料部のΔＥ効果は、磁歪材料部における磁化状態の変化に依存するため、磁化状態の変化量が小さいとΔＥ効果が生じ難い。
　一方、本実施形態では、伝搬路１４上に配置された集磁部１５ｃに外部磁界の磁束が集められるため、集磁部１５ｃの磁束密度が一対の磁束伝搬部１５ａ，１５ｂの磁束密度よりも高くなる。よって、集磁部１５ｃにおける磁歪が、集磁部１５ｃを設けない場合の非集磁部における磁歪よりも大きくなる。すなわち、集磁部１５ｃにおいて、磁化状態の変化に伴うΔＥ効果に加えて、集磁に伴う磁歪効果（ΔＥ効果）の増大により、伝搬路１４を伝搬するＳＨ－ＳＡＷの伝搬速度が大きく変化する。よって、例えば圧電基板１１に小さい応力が生じた場合、磁歪材料部１５に集磁部１５ｃを設けない場合と比較して、ＳＨ－ＳＡＷの伝搬速度の変化を十分に生じさせることができる。よって、例えば物理量センサ１を高感度な圧力センサとして機能させることができる。また、磁歪材料部１５に小さい外部磁界が印加された場合にも、ＳＨ－ＳＡＷの伝搬速度の変化を十分に生じさせることができる。したがって、本実施形態の物理量センサ１を高感度な磁気センサとしても機能させることができる。 Here, as described above, the ΔE effect of the magnetostrictive material portion depends on the change in the magnetization state in the magnetostrictive material portion. Therefore, if the amount of change in the magnetization state is small, the ΔE effect hardly occurs.
On the other hand, in the present embodiment, since the magnetic flux of the external magnetic field is collected in the magnetic flux collecting portion 15c arranged on the propagation path 14, the magnetic flux density of the magnetic flux collecting portion 15c is smaller than the magnetic flux density of the pair of magnetic flux transmitting portions 15a and 15b. Get higher. Therefore, the magnetostriction in the magnetic flux collecting portion 15c is larger than the magnetostriction in the non-magnetizing portion when the magnetic flux collecting portion 15c is not provided. In other words, in the magnetic flux collecting portion 15c, the propagation speed of the SH-SAW propagating through the propagation path 14 changes greatly due to the increase in the magnetostrictive effect (ΔE effect) caused by the magnetic flux collection in addition to the ΔE effect caused by the change in the magnetization state. . Therefore, for example, when a small stress is generated in the piezoelectric substrate 11, a change in the SH-SAW propagation speed can be sufficiently generated as compared with the case where the magnetic flux collecting portion 15c is not provided in the magnetostrictive material portion 15. Thus, for example, the physical quantity sensor 1 can function as a highly sensitive pressure sensor. Further, even when a small external magnetic field is applied to the magnetostrictive material portion 15, a change in the SH-SAW propagation speed can be sufficiently generated. Therefore, the physical quantity sensor 1 of the present embodiment can also function as a high-sensitivity magnetic sensor.
　ＳＡＷが第２電極部１３に到達すると、ＳＡＷに基づく出力信号が第２電極部１３から出力される。上記出力信号が検出回路部に入力されると、検出回路部により、ＳＡＷの伝搬特性の変化に基づいて、被検出体の物理量が検出される。上記被検出体としては、例えば生体、ビルや橋などの構造物の壁や支柱、コンピューター等の電子機器、テレビや冷蔵庫等の家電製品を挙げることができ、上記物理量としては、例えば磁界、トルク、圧力、温度、ガス量などを挙げることができる。 When the SAW reaches the second electrode unit 13, an output signal based on the SAW is output from the second electrode unit 13. When the output signal is input to the detection circuit, the detection circuit detects the physical quantity of the detection target based on a change in the propagation characteristic of the SAW. Examples of the detected object include living bodies, walls and columns of structures such as buildings and bridges, electronic devices such as computers, and home appliances such as televisions and refrigerators.The physical quantities include, for example, magnetic fields, torques, and the like. , Pressure, temperature, gas amount and the like.
　上述したように、本実施形態によれば、磁歪材料部１５が、一方の主面１１ａ上において一対の磁束伝搬部１５ａ，１５ｂの間に設けられ、弾性波の伝搬路１４上に配置された集磁部１５ｃを有するので、磁歪材料部１５に外部磁界を印加したときに集磁部１５ｃでの磁歪を増大させることができる。よって、伝搬路１４を伝搬するＳＨ－ＳＡＷの伝搬速度の変化を十分かつ効率的に生じさせることができ、従来よりも感度を向上して圧電基板１１に働く磁界または応力を精度良く検知することができる。 As described above, according to the present embodiment, the magnetostrictive material portion 15 is provided between the pair of magnetic flux propagation portions 15a and 15b on one main surface 11a, and is disposed on the elastic wave propagation path 14. Since the magnetic flux collecting portion 15c is provided, the magnetostriction in the magnetic flux collecting portion 15c can be increased when an external magnetic field is applied to the magnetostrictive material portion 15. Therefore, a change in the propagation speed of the SH-SAW propagating through the propagation path 14 can be sufficiently and efficiently generated, and the sensitivity is improved as compared with the related art, and the magnetic field or stress acting on the piezoelectric substrate 11 can be accurately detected. Can be.
　図２は、本発明の第２実施形態に係る弾性波変調素子を備える物理量センサの変形例を示す図であり、（ａ）は平面図、（ｂ）は線ＩＩ－ＩＩに沿う断面図、（ｃ）は底面図である。本実施形態では、磁歪材料部１５が、圧電基板１１の第１電極部１２及び第２電極部１３とは反対側の主面１１ｂに設けられている点で、上記第１実施形態とは異なる。その他の部分については第１実施形態と同様であるため、以下に第１実施形態と異なる部分を説明する。 2A and 2B are diagrams showing a modification of the physical quantity sensor including the elastic wave modulation element according to the second embodiment of the present invention, wherein FIG. 2A is a plan view, FIG. 2B is a cross-sectional view along line II-II, (C) is a bottom view. The present embodiment is different from the first embodiment in that the magnetostrictive material portion 15 is provided on the main surface 11b of the piezoelectric substrate 11 opposite to the first electrode portion 12 and the second electrode portion 13. . The other parts are the same as in the first embodiment, and therefore, the parts different from the first embodiment will be described below.
　図２（ａ）～（ｃ）に示すように、磁歪材料部２１は、圧電基板１１の一方の主面１１ｂ上に設けられ、外部磁界の磁束を伝搬可能な一対の磁束伝搬部２１ａ，２１ｂと、一方の主面１１ｂ上において一対の磁束伝搬部２１ａ，２１ｂの間に設けられ、弾性波の伝搬路１４の近傍（例えば、伝搬路１４の直下）に配置された集磁部２１ｃとを有する。 As shown in FIGS. 2A to 2C, the magnetostrictive material portion 21 is provided on one main surface 11b of the piezoelectric substrate 11, and is capable of transmitting a magnetic flux of an external magnetic field. And a magnetic flux collecting part 21c provided between the pair of magnetic flux transmitting parts 21a and 21b on one main surface 11b and arranged near the elastic wave propagation path 14 (for example, immediately below the propagation path 14). Have.
　本実施形態では、一対の磁束伝搬部２１ａ，２１ｂ及び集磁部２１ｃは、圧電基板１１の一方の主面１１ｂ上に配置されており、第１電極部１２及び前記第２電極部１３は、圧電基板１１の他方の主面１１ａ上に配置されている。本構成においても、集磁部２１ｃは、圧電基板１１の厚み方向の投影面において、第１電極部１２と第２電極部１３との間に配置されている（図２（ａ），（ｃ）参照）。 In the present embodiment, the pair of magnetic flux transmission units 21a and 21b and the magnetic flux collection unit 21c are arranged on one main surface 11b of the piezoelectric substrate 11, and the first electrode unit 12 and the second electrode unit 13 It is arranged on the other main surface 11 a of the piezoelectric substrate 11. Also in this configuration, the magnetic flux collecting portion 21c is disposed between the first electrode portion 12 and the second electrode portion 13 on the projection surface in the thickness direction of the piezoelectric substrate 11 (FIGS. 2A and 2C). )reference).
　ここで、圧電基板が、表面弾性波のうちのレイリー波を生じさせる構成である場合、レイリー波は圧電基板の表面に対して垂直な方向の変位を伴う。よって、磁歪材料部が第１，第２電極部と同じ主面上に設けられていると、レイリー波が磁歪材料部に伝搬して減衰が大きくなり、ＳＡＷの伝搬速度を十分に検知できない場合がある。 Here, when the piezoelectric substrate is configured to generate a Rayleigh wave of the surface acoustic waves, the Rayleigh wave involves displacement in a direction perpendicular to the surface of the piezoelectric substrate. Therefore, when the magnetostrictive material portion is provided on the same main surface as the first and second electrode portions, the Rayleigh wave propagates to the magnetostrictive material portion and the attenuation increases, and the SAW propagation speed cannot be sufficiently detected. There is.
　一方、本第２実施形態では、一対の磁束伝搬部２１ａ，２１ｂ及び集磁部２１ｃが、圧電基板１１の第１電極部１２及び第２電極部１３とは反対側の主面１１ｂに設けられているので、レイリー波が、第１電極部１２と第２電極部１３の間の伝搬路１４を伝搬して第２電極部１３に到達する際に、圧電基板１１の他方の主面１１ａを伝搬するレイリー波が、磁歪材料部２１、特に集磁部２１ｃに伝搬するのを抑制することができる。よって、集磁部２１ｃにおいて、磁化状態の変化に伴うΔＥ効果に加えて、集磁に伴う磁歪効果（ΔＥ効果）を増大させることができ、さらに、伝搬路１４を伝搬するレイリー波の減衰を抑制することが可能となり、レイリー波の伝搬速度の変化を十分かつ正確に生じさせることができる。 On the other hand, in the second embodiment, a pair of magnetic flux propagation portions 21a and 21b and a magnetic flux collection portion 21c are provided on the main surface 11b of the piezoelectric substrate 11 opposite to the first electrode portion 12 and the second electrode portion 13. Therefore, when the Rayleigh wave propagates through the propagation path 14 between the first electrode unit 12 and the second electrode unit 13 and reaches the second electrode unit 13, the other main surface 11 a of the piezoelectric substrate 11 The propagation of the propagating Rayleigh wave to the magnetostrictive material portion 21, in particular, the magnetic flux collecting portion 21c can be suppressed. Therefore, in the magnetic flux collecting portion 21c, the magnetostrictive effect (ΔE effect) due to the magnetic flux collection can be increased in addition to the ΔE effect due to the change in the magnetization state, and the attenuation of the Rayleigh wave propagating through the propagation path 14 can be reduced. This makes it possible to sufficiently and accurately generate a change in the propagation speed of the Rayleigh wave.
　図３（ａ）は、図１における弾性波変調素子１０の第１変形例を示す図であり、図３（ｂ）は、第２変形例を示す図である。
　上記第１実施形態では、集磁部１５ｃは、一対の磁束伝搬部１５ａ，１５ｂと一体で形成されているが、これに限られず、集磁部は一対の磁束伝搬部と別体で形成されていてもよい。 FIG. 3A is a diagram illustrating a first modification of the elastic wave modulation device 10 in FIG. 1, and FIG. 3B is a diagram illustrating a second modification.
In the first embodiment, the magnetic flux collecting portion 15c is formed integrally with the pair of magnetic flux transmitting portions 15a and 15b. However, the present invention is not limited thereto, and the magnetic flux collecting portion is formed separately from the pair of magnetic flux transmitting portions. May be.
　例えば、図３（ａ）に示すように、磁歪材料部３１の集磁部３１ｃが、一対の磁束伝搬部３１ａ，３１ｂと隙間を有するように離間して配置されてもよい。この場合、圧電基板１１の平面視において、集磁部３１ｃは矩形形状であり、一対の磁束伝搬部３１ａ，３１ｂの各々は扁平の台形状である。 3 For example, as shown in FIG. 3A, the magnetic flux collecting portion 31c of the magnetostrictive material portion 31 may be arranged to be separated from the pair of magnetic flux transmitting portions 31a and 31b so as to have a gap. In this case, in a plan view of the piezoelectric substrate 11, the magnetic flux collecting portion 31c has a rectangular shape, and each of the pair of magnetic flux transmitting portions 31a and 31b has a flat trapezoidal shape.
　また、図３（ｂ）に示すように、磁歪材料部３２の集磁部３２ｃが、一対の磁束伝搬部３２ａ，３２ｂと別体であるか或いは離間して配置されてもよい。この場合、圧電基板１１の平面視において、集磁部３２ｃは矩形状であり、磁束伝搬部３２ａは、扁平の矩形状を有する複数の部位３２ａ－１，３２ａ－１，…と、三角形状を有する部位３２ａ－２を有し、磁束伝搬部３２ｂは、扁平の矩形状を有する複数の部位３２ｂ－１，３２ｂ－１，…と、三角形状を有する部位３２ｂ－２を有する。 As shown in FIG. 3B, the magnetic flux collecting portion 32c of the magnetostrictive material portion 32 may be separate from the pair of magnetic flux transmitting portions 32a and 32b, or may be disposed separately. In this case, in a plan view of the piezoelectric substrate 11, the magnetic flux collecting portion 32c has a rectangular shape, and the magnetic flux transmitting portion 32a has a triangular shape with a plurality of flat portions 32a-1, 32a-1,. The magnetic flux propagation portion 32b has a plurality of flat portions 32b-1, 32b-1,... And a triangular portion 32b-2.
　本変形例の構成によっても、磁歪材料部３１，３２に外部磁界を印加したときに集磁部３１ｃ，３２ｃでの磁歪を増大させることができる。また、設計の自由度が向上し、更には圧電基板１１上に磁歪材料部３１，３２を容易に形成することができる。 According to the configuration of the present modification, the magnetostriction in the magnetic flux collecting parts 31c and 32c can be increased when an external magnetic field is applied to the magnetostrictive material parts 31 and 32. Further, the degree of freedom in design is improved, and the magnetostrictive material portions 31 and 32 can be easily formed on the piezoelectric substrate 11.
　図４は、図１における弾性波変調素子１０の第３変形例を示す図であり、（ａ）は平面図、（ｂ）は線ＩＩＩ－ＩＩＩに沿う断面図である。
　上記第１実施形態では、集磁部１５ｃにおける磁束が、弾性波の伝搬方向に垂直な方向に沿って形成されているが、これに限られず、集磁部における磁束が、弾性波の伝搬方向に沿って形成されてもよい。 FIGS. 4A and 4B are diagrams showing a third modification of the elastic wave modulation device 10 in FIG. 1, wherein FIG. 4A is a plan view, and FIG. 4B is a cross-sectional view along line III-III.
In the first embodiment, the magnetic flux in the magnetic flux collecting portion 15c is formed along the direction perpendicular to the propagation direction of the elastic wave. However, the present invention is not limited to this. May be formed along.
　例えば、磁歪材料部３３の一対の磁束伝搬部３３ａ，３３ｂ及び集磁部３３ｃは、圧電基板１１の一方の主面１１ａ上に配置され、第１電極部１２及び第２電極部１３は、圧電基板１１の一方の主面１１ａ上であって、一対の磁束伝搬部３３ａ，３３ｂに設けられた開口部３４ａ，３４ｂ（非成膜部）に対応する位置に配置される。また、上記一対の開口部を有さない一対の磁束伝搬部を設け、該一対の磁束伝搬部及び集磁部が、圧電基板１１の一方の主面１１ａ上に配置され、第１電極部１２及び第２電極部１３が、圧電基板１１の一方の主面１１ａ上であって当該一対の磁束伝搬部の下に配置されてもよい。本変形例の構成によっても、磁歪材料部３３に外部磁界を印加したときに集磁部３３ｃでの磁歪を増大させることができる。 For example, a pair of magnetic flux transmitting portions 33a, 33b and a magnetic flux collecting portion 33c of the magnetostrictive material portion 33 are disposed on one main surface 11a of the piezoelectric substrate 11, and the first electrode portion 12 and the second electrode portion 13 It is arranged on one main surface 11a of the substrate 11 at a position corresponding to the openings 34a and 34b (non-film-forming portions) provided in the pair of magnetic flux propagation portions 33a and 33b. In addition, a pair of magnetic flux transmitting portions not having the pair of openings is provided, and the pair of magnetic flux transmitting portions and the magnetic flux collecting portion are disposed on one main surface 11 a of the piezoelectric substrate 11. The second electrode portion 13 may be disposed on one main surface 11a of the piezoelectric substrate 11 and below the pair of magnetic flux transmitting portions. According to the configuration of the present modification, the magnetostriction in the magnetic flux collecting portion 33c can be increased when an external magnetic field is applied to the magnetostrictive material portion 33.
　また、上記一対の開口部を有さない一対の磁束伝搬部及び集磁部が、圧電基板１１の一方の主面１１ａ上に配置され、第１電極部１２及び第２電極部１３が、圧電基板１１の他方の主面１１ｂ上に配置されてもよい。 Further, a pair of magnetic flux transmitting portions and a magnetic flux collecting portion having no pair of openings are disposed on one main surface 11a of the piezoelectric substrate 11, and the first electrode portion 12 and the second electrode portion 13 It may be arranged on the other main surface 11 b of the substrate 11.
　更に、集磁部における磁束が、弾性波の伝搬方向（例えば、伝搬方向に平行な方向）に沿って形成され、一対の磁束伝搬部３３ａ，３３ｂ及び集磁部３３ｃが、圧電基板１１の一方の主面１１ａ上に配置され、第１電極部１２及び第２電極部１３が、圧電基板１１の一方の主面上であって集磁部３３ｃの下に配置されてもよい。 Further, the magnetic flux in the magnetic flux collecting portion is formed along the propagation direction of the elastic wave (for example, a direction parallel to the propagation direction), and the pair of magnetic flux transmitting portions 33 a and 33 b and the magnetic flux collecting portion 33 c are formed on one side of the piezoelectric substrate 11. The first electrode portion 12 and the second electrode portion 13 may be arranged on one main surface of the piezoelectric substrate 11 and below the magnetic flux collecting portion 33c.
　図５は、本発明の第３実施形態に係る弾性波変調素子の構成を概略的に示す図であり、（ａ）は平面図、（ｂ）は線ＩＶ－ＩＶに沿う断面図である。本第３実施形態では、第１電極部１２及び第２電極部１３が集磁部の下に設けられている点で、上記第１実施形態と異なる。第１実施形態と同様の構成については、第１実施形態と同一の符号を付してその説明を省略し、異なる部分を以下に説明する。 FIG. 5 is a view schematically showing a configuration of an elastic wave modulation element according to a third embodiment of the present invention, where (a) is a plan view and (b) is a cross-sectional view along line IV-IV. The third embodiment is different from the first embodiment in that the first electrode unit 12 and the second electrode unit 13 are provided below the magnetic flux collecting unit. About the structure similar to 1st Embodiment, the same code | symbol as 1st Embodiment is attached | subjected, The description is abbreviate | omitted, and a different part is demonstrated below.
　図５（ａ）に示すように、磁歪材料部３５の集磁部３５ｃが、一対の磁束伝搬部３５ａ，３５ｂと隙間を有するように離間して配置されている。そして、集磁部３５ｃは、圧電基板１１の厚み方向に投影した投影面において、第１電極部１２及び第２電極部１３を包含する位置に配置されている。 (5) As shown in FIG. 5A, the magnetic flux collecting portion 35c of the magnetostrictive material portion 35 is spaced apart from the pair of magnetic flux transmitting portions 35a and 35b so as to have a gap. The magnetic flux collecting portion 35c is disposed at a position including the first electrode portion 12 and the second electrode portion 13 on a projection plane projected in the thickness direction of the piezoelectric substrate 11.
　本実施形態では、第１電極部１２及び第２電極部１３が、圧電基板１１の一方の主面１１ａ上であって集磁部３５ｃの下に設けられているので、集磁部３５ｃの磁歪により、伝搬路を伝搬する弾性波の伝搬速度の変化をより効率的に生じさせることができる。よって、例えば本実施形態の構成を共振子型の物理量センサに適用することで、従来よりも感度を向上して圧電基板１１に働く応力を精度良く検知することができる。また、一対の磁束伝搬部３５ａ，３５ｂ及び集磁部３５ｃが、圧電基板１１の一方の主面１１ａ上に配置され、第１電極部１２及び第２電極部１３が、圧電基板１１の他方の主面１１ｂ上に配置されてもよい。 In the present embodiment, the first electrode portion 12 and the second electrode portion 13 are provided on one main surface 11a of the piezoelectric substrate 11 and below the magnetic flux collecting portion 35c. Thereby, the change in the propagation speed of the elastic wave propagating in the propagation path can be more efficiently generated. Therefore, for example, by applying the configuration of the present embodiment to a resonator-type physical quantity sensor, it is possible to improve the sensitivity as compared with the related art and accurately detect the stress applied to the piezoelectric substrate 11. Further, a pair of magnetic flux propagation portions 35a, 35b and a magnetic flux collecting portion 35c are arranged on one main surface 11a of the piezoelectric substrate 11, and the first electrode portion 12 and the second electrode portion 13 are arranged on the other side of the piezoelectric substrate 11. It may be arranged on the main surface 11b.
　尚、図５（ｂ）に示すように、弾性波変調素子の断面視において、集磁部３５ｃの下部が、櫛歯形状を有し、一対の櫛歯電極１２ａ，１２ｂ間および一対の櫛歯電極１３ａ，１３ｂ間に入り込んでいるのが好ましい。これにより、集磁部３５ｃを圧電基板１１により近い位置に配置することができ、弾性波の伝搬速度の変化を更に効率的に生じさせることができる。また、磁歪材料部３５（特に集磁部３５ｃ）が金属で構成される場合、電極間の短絡防止の観点から、弾性波変調素子は、圧電基板１１、第１電極部１２および第２電極部１３を覆って形成された絶縁層２０を更に有するのが好ましい。 As shown in FIG. 5B, in a sectional view of the elastic wave modulating element, a lower portion of the magnetic flux collecting portion 35c has a comb-tooth shape, between a pair of comb- tooth electrodes 12a and 12b and a pair of comb-tooth electrodes. It is preferable that it penetrates between the electrodes 13a and 13b. Thereby, the magnetic flux collecting portion 35c can be arranged at a position closer to the piezoelectric substrate 11, and the change in the propagation speed of the elastic wave can be more efficiently generated. When the magnetostrictive material portion 35 (particularly, the magnetic flux collecting portion 35c) is made of metal, the elastic wave modulating element includes the piezoelectric substrate 11, the first electrode portion 12, and the second electrode portion from the viewpoint of preventing a short circuit between the electrodes. It is preferable to further include an insulating layer 20 formed so as to cover 13.
　また、本実施形態では、集磁部３５ｃにおける磁束が、弾性波の伝搬方向に垂直な方向に沿って形成されているが、これに限られず、集磁部３５ｃにおける磁束が、弾性波の伝搬方向に沿って形成されてもよい。またこのとき、一対の磁束伝搬部３５ａ，３５ｂ及び集磁部３５ｃが、圧電基板１１の一方の主面１１ａ上に配置され、第１電極部１２及び第２電極部１３が、圧電基板１１の一方の主面１１ａ上であって集磁部３５ｃの下に配置されるか、圧電基板１１の他方の主面１１ｂ上に配置されてもよい。 Further, in the present embodiment, the magnetic flux in the magnetic flux collecting portion 35c is formed along a direction perpendicular to the propagation direction of the elastic wave. It may be formed along a direction. At this time, a pair of magnetic flux transmitting portions 35a and 35b and a magnetic flux collecting portion 35c are arranged on one main surface 11a of the piezoelectric substrate 11, and the first electrode portion 12 and the second electrode portion 13 It may be arranged on one main surface 11a and below magnetic flux collecting portion 35c, or may be arranged on the other main surface 11b of piezoelectric substrate 11.
　図６（ａ）は、本発明の第４実施形態に係る弾性波変調素子を備える物理量センサの構成を概略的に示す平面図であり、図６（ｂ）は、第４実施形態の変形例を示す平面図である。本第４実施形態では、物理量センサが共振子型である場合を例に挙げて説明する。物理量センサが共振子型であること以外は第３実施形態と同様であるため、以下に第３実施形態と異なる部分を説明する。 FIG. 6A is a plan view schematically showing a configuration of a physical quantity sensor including an elastic wave modulation element according to a fourth embodiment of the present invention, and FIG. 6B is a modification of the fourth embodiment. FIG. In the fourth embodiment, a case where the physical quantity sensor is a resonator type will be described as an example. Since the physical quantity sensor is the same as that of the third embodiment except that the physical quantity sensor is of the resonator type, parts different from the third embodiment will be described below.
　図６（ａ）に示すように、物理量センサ２の弾性波変調素子４０は、圧電基板１１に取り付けられ、第１電極部１２及び第２電極部１３の両側に配置された一対の反射器４１ａ，４１ｂを更に備える。本実施形態では、第１電極部１２が、互いの歯が交互に並ぶように対向して配置された一対の櫛歯電極のうちの櫛歯電極４２ａ（一対の櫛歯電極のうちの一方）を構成し、第２電極部１３が、上記一対の櫛歯電極のうちの櫛歯電極４２ｂ（一対の櫛歯電極のうちの他方）を構成している。一対の櫛歯電極のうちの櫛歯電極４２ａは入力部１７に接続され、櫛歯電極４２ｂは出力部１８に接続されている。弾性波変調素子４０は、いわゆる１ポート共振子を構成している。 As shown in FIG. 6A, the elastic wave modulating element 40 of the physical quantity sensor 2 is attached to the piezoelectric substrate 11, and a pair of reflectors 41a disposed on both sides of the first electrode unit 12 and the second electrode unit 13. , 41b. In the present embodiment, the first electrode portion 12 is a comb-shaped electrode 42a (one of a pair of comb-shaped electrodes) of a pair of comb-shaped electrodes arranged to face each other such that the teeth are alternately arranged. And the second electrode portion 13 forms the comb electrode 42b (the other of the pair of comb electrodes) of the pair of comb electrodes. The comb electrode 42 a of the pair of comb electrodes is connected to the input unit 17, and the comb electrode 42 b is connected to the output unit 18. The elastic wave modulating element 40 forms a so-called one-port resonator.
　この弾性波変調素子４０では、一対の反射器４１ａ，４１ｂが一対の櫛歯電極４２ａ，４２ｂの両側に配置されており、一対の櫛歯電極４２ａ，４２ｂによって励振した弾性波が、一対の反射器４１ａ，４１ｂ間に閉じ込められる。このとき、一対の櫛歯電極４２ａ，４２ｂが圧電基板１１の一方の主面１１ａ上であって集磁部１５ｃの下に配置されているので、集磁部１５ｃの磁歪により、伝搬路１４を伝搬する弾性波（あるいは定在波）の伝搬速度の変化をより効率的に生じさせることができる。よって、本実施形態の構成を１ポート共振子型の物理量センサに適用することで、従来よりも感度を向上して圧電基板１１に働く応力を精度良く検知することができる。 In this elastic wave modulating element 40, a pair of reflectors 41a and 41b are arranged on both sides of a pair of comb electrodes 42a and 42b, and an elastic wave excited by the pair of comb electrodes 42a and 42b is reflected by a pair of reflection electrodes. It is confined between the vessels 41a and 41b. At this time, since the pair of comb- teeth electrodes 42a and 42b are arranged on one main surface 11a of the piezoelectric substrate 11 and below the magnetic flux collecting portion 15c, the propagation path 14 is caused by the magnetostriction of the magnetic flux collecting portion 15c. A change in the propagation speed of the propagating elastic wave (or standing wave) can be caused more efficiently. Therefore, by applying the configuration of the present embodiment to a one-port resonator type physical quantity sensor, it is possible to improve the sensitivity as compared with the related art and accurately detect the stress applied to the piezoelectric substrate 11.
　また、図６（ｂ）に示すように、物理量センサ３の弾性波変調素子５０は、いわゆる２ポート共振子を構成してもよい。すなわち、弾性波変調素子５０は、圧電基板１１に取り付けられ、第１電極部１２及び第２電極部１３の両側に配置された一対の反射器５１ａ，５１ｂを更に備えてもよい。本変形例では、第１電極部１２が、互いの歯が交互に並ぶように対向して配置された一対の櫛歯電極１２ａ，１２ｂで構成され、第２電極部１３が、互いの歯が交互に並ぶように対向して配置された一対の櫛歯電極１３ａ，１３ｂで構成されている。一対の櫛歯電極１２ａ，１２ｂは入力部１７に接続され、一対の櫛歯電極１３ａ，１３ｂは出力部１８に接続されている。また、磁歪材料部１５は、圧電基板１１の一方の主面１１ａ上に設けられ、外部磁界の磁束を伝搬可能な一対の磁束伝搬部３６ａ，３６ｂと、一方の主面１１ａ上において一対の磁束伝搬部３６ａ，３６ｂの間に設けられ、弾性波の伝搬路１４の近傍に配置された集磁部３６ｃとを有している。 As shown in FIG. 6B, the elastic wave modulating element 50 of the physical quantity sensor 3 may constitute a so-called two-port resonator. That is, the elastic wave modulation element 50 may further include a pair of reflectors 51 a and 51 b attached to the piezoelectric substrate 11 and arranged on both sides of the first electrode unit 12 and the second electrode unit 13. In the present modification, the first electrode unit 12 is constituted by a pair of comb- teeth electrodes 12a and 12b arranged so as to face each other such that the teeth are alternately arranged. It is composed of a pair of comb- tooth electrodes 13a and 13b arranged so as to face each other alternately. The pair of comb electrodes 12a and 12b are connected to the input unit 17, and the pair of comb electrodes 13a and 13b are connected to the output unit 18. Further, the magnetostrictive material portion 15 is provided on one main surface 11a of the piezoelectric substrate 11 and is capable of transmitting a magnetic flux of an external magnetic field. A magnetic flux collecting portion 36c provided between the propagation portions 36a and 36b and arranged near the elastic wave propagation path 14;
　本変形例では、一対の櫛歯電極１２ａ，１２ｂ及び一対の櫛歯電極１３ａ，１３ｂが共に、圧電基板１１の一方の主面１１ａ上であって集磁部３６ｃの下に配置されているので、集磁部３６ｃの磁歪により、伝搬路を伝搬する弾性波（あるいは定常波）の伝搬速度の変化をより効率的に生じさせることができる。このように、弾性波変調素子５０の構成を２ポート共振子型の物理量センサに適用することによっても、図６（ａ）の構成の場合と同様のメカニズムにより、従来よりも感度を向上して圧電基板１１に働く応力を精度良く検知することができる。 In this modification, the pair of comb electrodes 12a and 12b and the pair of comb electrodes 13a and 13b are both disposed on one main surface 11a of the piezoelectric substrate 11 and below the magnetic flux collecting portion 36c. Due to the magnetostriction of the magnetic flux collecting portion 36c, a change in the propagation speed of the elastic wave (or the standing wave) propagating through the propagation path can be caused more efficiently. As described above, by applying the configuration of the elastic wave modulation element 50 to the two-port resonator type physical quantity sensor, the sensitivity is improved as compared with the conventional configuration by the same mechanism as that of the configuration of FIG. The stress acting on the piezoelectric substrate 11 can be accurately detected.
　図７は、本発明の第５実施形態に係る弾性波変調素子を備える物理量センサの構成を概略的に示す平面図である。本第５実施形態では、物理量センサが遅延線型の弾性波変調素子とアンテナ部とを備える場合を例に挙げて説明する。物理量センサが遅延線型の弾性波変調素子とアンテナ部とを備えること以外は第３実施形態（図６（ａ））と同様であるため、以下に第３実施形態と異なる部分を説明する。 FIG. 7 is a plan view schematically showing a configuration of a physical quantity sensor including an elastic wave modulation element according to a fifth embodiment of the present invention. In the fifth embodiment, a case where the physical quantity sensor includes a delay line type elastic wave modulation element and an antenna unit will be described as an example. The physical quantity sensor is the same as the third embodiment (FIG. 6A) except that the physical quantity sensor includes a delay line-type elastic wave modulation element and an antenna unit, and therefore, different points from the third embodiment will be described below.
　図７に示すように、物理量センサ４の弾性波変調素子６０は、圧電基板１１に取り付けられ、圧電基板１１に弾性波を励起または受信する第１電極部１２および第２電極部１３と、圧電基板１１に取り付けられ、集磁部１５ｃの一方側に配置された一の反射器６１を備える。本実施形態では、第１電極部１２および第２電極部が、圧電基板１１に弾性波を励起または受信する一対の櫛歯電極４３ａ，４３ｂである。一対の櫛歯電極４３ａ，４３ｂのうちの櫛歯電極４３ａはアンテナ部１９に接続され、櫛歯電極４３ｂは接地されている。そして、第１電極部１２及び第２電極部１３は、圧電基板１１の一方の主面１１ａ上であって集磁部１５ｃの他方側に配置されている。第１電極部１２及び第２電極部１３は、圧電基板１１の一方の主面１１ａ上であって集磁部１３ｃの下に配置されてもよい。 As shown in FIG. 7, the elastic wave modulating element 60 of the physical quantity sensor 4 is attached to the piezoelectric substrate 11, and the first electrode unit 12 and the second electrode unit 13 for exciting or receiving the elastic wave to the piezoelectric substrate 11, It includes one reflector 61 attached to the substrate 11 and arranged on one side of the magnetic flux collecting portion 15c. In the present embodiment, the first electrode unit 12 and the second electrode unit are a pair of comb- teeth electrodes 43a and 43b that excite or receive an elastic wave on the piezoelectric substrate 11. The comb electrode 43a of the pair of comb electrodes 43a and 43b is connected to the antenna unit 19, and the comb electrode 43b is grounded. The first electrode portion 12 and the second electrode portion 13 are arranged on one main surface 11a of the piezoelectric substrate 11 and on the other side of the magnetic flux collecting portion 15c. The first electrode portion 12 and the second electrode portion 13 may be arranged on one main surface 11a of the piezoelectric substrate 11 and below the magnetic flux collecting portion 13c.
　この弾性波変調素子６０では、アンテナ部１９で電波を受信すると、一対の櫛歯電極４３ａ，４３ｂによって励振した弾性波が、圧電基板１１の伝搬路１４を介して反射器６１に到達する。その後、反射器６１での反射によって生じた反射波が伝搬路１４を介して一対の櫛歯電極４３ａ，４３ｂに到達し、アンテナ部１９から電波が送信される。このとき、集磁部１５ｃが弾性波の伝搬路１４上に配置されているので、集磁部１５ｃの磁歪により、伝搬路を伝搬する弾性波の伝搬速度の変化をより効率的に生じさせることができる。よって、本実施形態の構成を、遅延線型の弾性波変調素子とアンテナ部とを備える物理量センサに適用することで、ワイヤレスで、従来よりも感度を向上して圧電基板１１に働く応力または磁界を精度良く検知することが可能となる。 In the elastic wave modulating element 60, when a radio wave is received by the antenna unit 19, the elastic wave excited by the pair of comb- teeth electrodes 43a and 43b reaches the reflector 61 via the propagation path 14 of the piezoelectric substrate 11. After that, the reflected wave generated by the reflection at the reflector 61 reaches the pair of comb- teeth electrodes 43 a and 43 b via the propagation path 14, and the radio wave is transmitted from the antenna unit 19. At this time, since the magnetic flux collecting portion 15c is arranged on the elastic wave propagation path 14, the change in the propagation speed of the elastic wave propagating through the propagation path can be more efficiently caused by the magnetostriction of the magnetic flux collecting portion 15c. Can be. Therefore, by applying the configuration of the present embodiment to a physical quantity sensor including a delay line type elastic wave modulation element and an antenna unit, the sensitivity or the magnetic field acting on the piezoelectric substrate 11 can be wirelessly improved by improving the sensitivity compared to the related art. It is possible to detect with high accuracy.
　以上、本発明の実施形態について詳述したが、本発明は上記実施形態に限定されるものではなく、特許請求の範囲内に記載された本発明の要旨の範囲内において、種々の変形・変更が可能である。 As described above, the embodiments of the present invention have been described in detail. However, the present invention is not limited to the above embodiments, and various modifications and changes may be made within the scope of the present invention described in the appended claims. Is possible.
　例えば、図７の弾性波変調素子６０は、一の反射器を備えているが、これに限らず、１電極部及び第２電極部の両側に配置された一対の反射器を備えていてもよい。またこのとき、第１電極部及び第２電極部は、圧電基板１１の一方の主面１１ａ上であって集磁部の下に配置されてもよい（図６（ａ），（ｂ）参照）。 For example, the elastic wave modulating element 60 in FIG. 7 includes one reflector, but is not limited thereto, and may include a pair of reflectors disposed on both sides of the one electrode unit and the second electrode unit. Good. At this time, the first electrode portion and the second electrode portion may be arranged on one main surface 11a of the piezoelectric substrate 11 and below the magnetic flux collecting portion (see FIGS. 6A and 6B). ).
　また、図６（ａ）において、一対の反射器４１ａ，４１ｂは、集磁部１５ｃの両側に取り付けられているが、これに限られない。集磁部１５ｃが、圧電基板１１の厚み方向に投影した投影面において、一対の反射器４１ａ，４１ｂを包含する位置に配置されてもよい。また、一対の反射器４１ａ，４１ｂが、圧電基板１１の一方の主面１１ａ上であって集磁部１５ｃの下に配置されてもよい。
　同様に、図６（ｂ）において、一対の反射器５１ａ，５１ｂは、集磁部３６ｃの両側に取り付けられているが、これに限られない。集磁部３６ｃが、圧電基板１１の厚み方向に投影した投影面において、一対の反射器５１ａ，５１ｂを包含する位置に配置されてもよい。また、一対の反射器５１ａ，５１ｂが、圧電基板１１の一方の主面１１ａ上であって集磁部３６ｃの下に配置されてもよい。
　更に、図７において、反射器６１は、集磁部１５ｃの一方側に取り付けられているが、これに限られない。集磁部１５ｃが、圧電基板１１の厚み方向に投影した投影面において、一の反射器６１を包含する位置に配置され、一の反射器６１が、圧電基板１１の一方の主面１１ａ上であって集磁部１５ｃの下に配置されてもよい。 Further, in FIG. 6A, the pair of reflectors 41a and 41b are attached to both sides of the magnetic flux collecting part 15c, but the present invention is not limited to this. The magnetic flux collection unit 15c may be disposed at a position that includes the pair of reflectors 41a and 41b on the projection surface that is projected in the thickness direction of the piezoelectric substrate 11. Further, the pair of reflectors 41a and 41b may be arranged on one main surface 11a of the piezoelectric substrate 11 and below the magnetic flux collecting portion 15c.
Similarly, in FIG. 6B, the pair of reflectors 51a and 51b are attached to both sides of the magnetic flux collecting part 36c, but are not limited thereto. The magnetic flux collecting portion 36c may be arranged at a position including the pair of reflectors 51a and 51b on the projection surface projected in the thickness direction of the piezoelectric substrate 11. Further, the pair of reflectors 51a and 51b may be arranged on one main surface 11a of the piezoelectric substrate 11 and below the magnetic flux collecting portion 36c.
Further, in FIG. 7, the reflector 61 is attached to one side of the magnetic flux collecting portion 15c, but is not limited thereto. The magnetic flux collecting portion 15c is arranged at a position including the one reflector 61 on a projection plane projected in the thickness direction of the piezoelectric substrate 11, and the one reflector 61 is disposed on one main surface 11a of the piezoelectric substrate 11. Therefore, it may be arranged below the magnetic flux collecting portion 15c.
　本発明の弾性波変調素子は、磁界、トルク、圧力、温度等の各種物理量センサに適用することができる。 弾 性 The elastic wave modulation element of the present invention can be applied to various physical quantity sensors for magnetic field, torque, pressure, temperature and the like.
１　物理量センサ
２　物理量センサ
３　物理量センサ
４　物理量センサ
１０　弾性波変調素子
１１　圧電基板
１１ａ　主面
１１ｂ　主面
１２　第１電極部
１２ａ　櫛歯電極
１２ｂ　櫛歯電極
１３　第２電極部
１３ａ　櫛歯電極
１３ｂ　櫛歯電極
１４　伝搬路
１５　磁歪材料部
１５ａ　磁束伝搬部
１５ｂ　磁束伝搬部
１５ｃ　集磁部
１６　磁界印加部
１７　入力部
１８　出力部
１９　アンテナ部
２０　絶縁層
２１　磁歪材料部
２１ａ　磁束伝搬部
２１ｂ　磁束伝搬部
２１ｃ　集磁部
３１　磁歪材料部
３１ａ　磁束伝搬部
３１ｂ　磁束伝搬部
３１ｃ　集磁部
３２　磁歪材料部
３２ａ　磁束伝搬部
３２ａ－１　部位
３２ａ－２　部位
３２ｂ　磁束伝搬部
３２ｂ－１　部位
３２ｂ－２　部位
３２ｃ　集磁部
３３　磁歪材料部
３３ａ　磁束伝搬部
３３ｂ　磁束伝搬部
３３ｃ　集磁部
３４ａ　開口部
３４ｂ　開口部
３５　磁歪材料部
３５ａ　磁束伝搬部
３５ｂ　磁束伝搬部
３５ｃ　集磁部
３６ａ　磁束伝搬部
３６ｂ　磁束伝搬部
３６ｃ　集磁部
４０　弾性波変調素子
４１ａ　反射器
４１ｂ　反射器
４２ａ　櫛歯電極
４２ｂ　櫛歯電極
４３ａ　櫛歯電極
４３ｂ　櫛歯電極
５０　弾性波変調素子
５１ａ　反射器
５１ｂ　反射器
６０　弾性波変調素子
６１　反射器 REFERENCE SIGNS LIST 1 physical quantity sensor 2 physical quantity sensor 3 physical quantity sensor 4 physical quantity sensor 10 elastic wave modulation element 11 piezoelectric substrate 11a main surface 11b main surface 12 first electrode portion 12a comb electrode 12b comb electrode 13 second electrode portion 13a comb electrode 13b comb Tooth electrode 14 Propagation path 15 Magnetostrictive material section 15a Flux propagation section 15b Flux propagation section 15c Magnetic flux collection section 16 Magnetic field application section 17 Input section 18 Output section 19 Antenna section 20 Insulating layer 21 Magnetostrictive material section 21a Flux propagation section 21b Flux propagation section 21c Magnetic flux collecting portion 31 Magnetostrictive material portion 31a Magnetic flux transmitting portion 31b Magnetic flux transmitting portion 31c Magnetic flux collecting portion 32 Magnetostrictive material portion 32a Magnetic flux transmitting portion 32a-1 Part 32a-2 Part 32b Magnetic flux transmitting part 32b-1 Part 32b-2 Part 32c Magnetic flux collecting Part 33 magnetostrictive material part 33a magnetic flux propagation part 33b magnetic flux propagation part 33c magnetic flux collecting part 34a opening 34b opening 35 magnetism Material section 35a Magnetic flux propagation section 35b Magnetic flux propagation section 35c Magnetic flux collection section 36a Magnetic flux propagation section 36b Magnetic flux propagation section 36c Magnetic flux collection section 40 Elastic wave modulation element 41a Reflector 41b Reflector 42a Comb electrode 42b Comb electrode 43a Comb electrode 43b Comb-tooth electrode 50 Elastic wave modulation element 51a Reflector 51b Reflector 60 Elastic wave modulation element 61 Reflector

Claims (15)

  1. 　圧電基板と、
    　前記圧電基板に取り付けられ、前記圧電基板に弾性波を励起する第１電極部と、
    　前記圧電基板に取り付けられ、前記弾性波を受信する第２電極部と、
    　前記弾性波の存在領域またはその近傍に設けられた磁歪材料部と、
    　を備え、
    　前記磁歪材料部は、
    　前記圧電基板の一方の主面上に設けられ、外部磁界の磁束を伝搬可能な一対の磁束伝搬部と、
    　前記一方の主面上において前記一対の磁束伝搬部の間に設けられ、前記弾性波の伝搬路上またはその近傍に配置された集磁部と、
    　を有する、
    　ことを特徴とする弾性波変調素子。     A piezoelectric substrate,
    A first electrode unit attached to the piezoelectric substrate and exciting an elastic wave to the piezoelectric substrate;
    A second electrode unit attached to the piezoelectric substrate and receiving the elastic wave;
    Magnetostrictive material portion provided in or near the elastic wave existence region,
    With
    The magnetostrictive material section includes:
    A pair of magnetic flux transmission units provided on one main surface of the piezoelectric substrate and capable of transmitting a magnetic flux of an external magnetic field,
    A magnetic flux collection unit provided between the pair of magnetic flux transmission units on the one main surface, and disposed on or near the elastic wave propagation path;
    Having,
    An elastic wave modulating element characterized by the above-mentioned.
  2. 　前記一対の磁束伝搬部の各々は、前記集磁部とは反対側の一端部から前記集磁部側の他端部に向かう方向に沿って断面積が小さくなる形状を有し、
    　前記集磁部の磁場方向に垂直な断面積の最小値が、前記一対の磁束伝搬部の前記断面積の最小値と同じかそれよりも小さい、請求項１記載の弾性波変調素子。     Each of the pair of magnetic flux propagation portions has a shape in which a cross-sectional area decreases along a direction from one end portion on the opposite side to the magnetic flux collection portion toward the other end portion on the magnetic flux collection portion side,
    The elastic wave modulating element according to claim 1, wherein a minimum value of a cross-sectional area of the magnetic flux collection unit perpendicular to a magnetic field direction is equal to or smaller than a minimum value of the cross-sectional area of the pair of magnetic flux propagation units.
  3. 　前記集磁部は、前記圧電基板の厚み方向の投影面において、前記第１電極部と第２電極部との間に配置される、請求項１または２に記載の弾性波変調素子。 3. The elastic wave modulation device according to claim 1, wherein the magnetic flux collection unit is disposed between the first electrode unit and the second electrode unit on a projection plane in the thickness direction of the piezoelectric substrate. 4.
  4. 　前記集磁部における磁束が、前記弾性波の伝搬方向に垂直な方向に沿って形成され、
    　前記一対の磁束伝搬部及び前記集磁部は、前記圧電基板の一方の主面上に配置され、
    　前記第１電極部及び前記第２電極部は、前記圧電基板の前記一方の主面上に配置されるか、または前記圧電基板の他方の主面上に配置される、請求項３に記載の弾性波変調素子。     The magnetic flux in the magnetic flux collector is formed along a direction perpendicular to the propagation direction of the elastic wave,
    The pair of magnetic flux transmission units and the magnetic flux collection unit are disposed on one main surface of the piezoelectric substrate,
    4. The piezoelectric device according to claim 3, wherein the first electrode unit and the second electrode unit are disposed on the one main surface of the piezoelectric substrate or on the other main surface of the piezoelectric substrate. 5. Elastic wave modulator.
  5. 　前記集磁部における磁束が、前記弾性波の伝搬方向に沿って形成され、
    　前記一対の磁束伝搬部及び前記集磁部は、前記圧電基板の一方の主面上に配置され、
    　前記第１電極部及び前記第２電極部は、前記一方の主面上であって前記一対の磁束伝搬部に設けられた一対の開口部に対応する位置に配置されるか、前記一方の主面上であって前記一対の磁束伝搬部の下に配置されるか、または、前記圧電基板の他方の主面上に配置される、請求項３に記載の弾性波変調素子。     A magnetic flux in the magnetic flux collection unit is formed along a propagation direction of the elastic wave,
    The pair of magnetic flux transmission units and the magnetic flux collection unit are disposed on one main surface of the piezoelectric substrate,
    The first electrode portion and the second electrode portion are disposed on the one main surface at positions corresponding to a pair of openings provided in the pair of magnetic flux transmission portions, or The elastic wave modulation device according to claim 3, wherein the elastic wave modulation device is disposed on a surface and below the pair of magnetic flux propagation portions, or disposed on the other main surface of the piezoelectric substrate.
  6. 　前記集磁部は、前記圧電基板の厚み方向に投影した投影面において、前記第１電極部及び前記第２電極部を包含する位置に配置される、請求項１または２に記載の弾性波変調素子。 The elastic wave modulation according to claim 1, wherein the magnetic flux collection unit is arranged at a position including the first electrode unit and the second electrode unit on a projection plane projected in a thickness direction of the piezoelectric substrate. element.
  7. 　前記集磁部における磁束が、前記弾性波の伝搬方向に垂直な方向に沿って形成され、
    　前記一対の磁束伝搬部及び前記集磁部は、前記圧電基板の一方の主面上に配置され、
    　前記第１電極部及び前記第２電極部が、前記圧電基板の前記一方の主面上であって前記集磁部の下に配置されるか、または前記圧電基板の他方の主面上に配置される、請求項６に記載の弾性波変調素子。     The magnetic flux in the magnetic flux collector is formed along a direction perpendicular to the propagation direction of the elastic wave,
    The pair of magnetic flux transmission units and the magnetic flux collection unit are disposed on one main surface of the piezoelectric substrate,
    The first electrode portion and the second electrode portion are disposed on the one main surface of the piezoelectric substrate and below the magnetic flux collecting portion, or disposed on the other main surface of the piezoelectric substrate. The elastic wave modulation device according to claim 6, wherein:
  8. 　前記集磁部における磁束が、前記弾性波の伝搬方向に沿って形成され、
    　前記一対の磁束伝搬部及び前記集磁部は、前記圧電基板の一方の主面上に配置され、
    　前記第１電極部及び前記第２電極部が、前記圧電基板の前記一方の主面上であって前記集磁部の下に配置されるか、または、前記圧電基板の他方の主面上に配置される、請求項６に記載の弾性波変調素子。     A magnetic flux in the magnetic flux collection unit is formed along a propagation direction of the elastic wave,
    The pair of magnetic flux transmission units and the magnetic flux collection unit are disposed on one main surface of the piezoelectric substrate,
    The first electrode portion and the second electrode portion are disposed on the one main surface of the piezoelectric substrate and below the magnetic flux collecting portion, or on the other main surface of the piezoelectric substrate. The elastic wave modulation device according to claim 6, which is arranged.
  9. 　前記第１電極部が、互いの歯が交互に並ぶように対向して配置された一対の櫛歯電極で構成され、
    　前記第２電極部が、互いの歯が交互に並ぶように対向して配置された他の一対の櫛歯電極で構成される、請求項１～８のいずれか１項に記載の弾性波変調素子。     The first electrode portion is constituted by a pair of comb-shaped electrodes arranged so as to face each other so that the teeth are alternately arranged;
    The elastic wave modulation according to any one of claims 1 to 8, wherein the second electrode unit includes another pair of comb-shaped electrodes arranged so as to face each other so that the teeth are alternately arranged. element.
  10. 　前記第１電極部および前記第２電極部が、前記圧電基板に弾性波を励起または受信する一対の櫛歯電極である、請求項１～８のいずれか１項に記載の弾性波変調素子。 The elastic wave modulation device according to any one of claims 1 to 8, wherein the first electrode portion and the second electrode portion are a pair of comb-shaped electrodes that excite or receive an elastic wave on the piezoelectric substrate.
  11. 　前記圧電基板に取り付けられ、前記集磁部の一方側に配置された一の反射器を更に備え、
    　前記第１電極部及び前記第２電極部が、前記圧電基板の一方の主面上であって前記集磁部の他方側に配置されるか、または前記圧電基板の一方の主面上であって前記集磁部の下に配置される、請求項１～１０のいずれか１項に記載の弾性波変調素子。     One reflector attached to the piezoelectric substrate and arranged on one side of the magnetic flux collecting part,
    The first electrode portion and the second electrode portion are disposed on one main surface of the piezoelectric substrate and on the other side of the magnetic flux collecting portion, or on one main surface of the piezoelectric substrate. The elastic wave modulating element according to any one of claims 1 to 10, wherein the element is arranged below the magnetic flux collecting part.
  12. 　前記集磁部は、前記圧電基板の厚み方向に投影した投影面において、前記一の反射器を包含する位置に配置され、
    　前記一の反射器が、圧電基板の前記一方の主面上であって前記集磁部の下に配置される、請求項１１に記載の弾性波変調素子。     The magnetic flux collection unit is disposed at a position that includes the one reflector on a projection plane that is projected in the thickness direction of the piezoelectric substrate,
    The acoustic wave modulation device according to claim 11, wherein the one reflector is disposed on the one main surface of the piezoelectric substrate and below the magnetic flux collection part.
  13. 　前記圧電基板に取り付けられ、前記第１電極部及び前記第２電極部の両側に配置された一対の反射器を更に備える、請求項１～１０のいずれか１項に記載の弾性波変調素子。 The elastic wave modulation device according to any one of claims 1 to 10, further comprising a pair of reflectors attached to the piezoelectric substrate and arranged on both sides of the first electrode unit and the second electrode unit.
  14. 　前記集磁部は、前記圧電基板の厚み方向に投影した投影面において、前記一対の反射器を包含する位置に配置され、
    　前記一対の反射器が、圧電基板の前記一方の主面上であって前記集磁部の下に配置される、請求項１３に記載の弾性波変調素子。     The magnetic flux collection unit is disposed at a position that includes the pair of reflectors on a projection plane that is projected in a thickness direction of the piezoelectric substrate,
    14. The acoustic wave modulation device according to claim 13, wherein the pair of reflectors are arranged on the one main surface of the piezoelectric substrate and below the magnetic flux collecting part.
  15. 　請求項１～１４のいずれか１項に記載の弾性波変調素子と、前記弾性波変調素子の変調を検出する回路部と、を備える物理量センサ。 A physical quantity sensor comprising: the elastic wave modulation element according to any one of claims 1 to 14; and a circuit unit that detects modulation of the elastic wave modulation element.
PCT/JP2018/036364 2018-09-28 2018-09-28 Acoustic wave modulation element and physical quantity sensor WO2020065941A1 (en)

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