JP5109871B2 - Spherical surface acoustic wave device - Google Patents

Description

  The present invention relates to a spherical surface acoustic wave device.

  A surface acoustic wave circuit that is formed continuously in an annular shape by at least a part of a spherical shape and can excite surface acoustic waves, and the excited surface acoustic waves can propagate and circulate in the continuous direction of the ring. A surface acoustic wave propagation substrate included on the outer surface; and disposed on or opposite to the surface acoustic wave circuit of the surface acoustic wave propagation substrate, and the surface acoustic wave circuit is excited by exciting the surface acoustic wave. A surface acoustic wave that propagates in a continuous direction of the ring and circulates, and detects a surface acoustic wave that circulates the surface acoustic wave circuit and generates a received signal corresponding to the surface acoustic wave that has circulated A spherical surface acoustic wave device including a wave / excitation / detection means is already well known, for example, from FIGS. 1 and 7 of Japanese Patent Laid-Open No. 2005-94609 (Patent Document 1).

  The surface acoustic wave propagation substrate is a base formed using a material that cannot excite a surface acoustic wave so that the outer surface includes at least a part that is continuously formed in an annular shape by a part of a spherical shape. It is formed by coating at least the annular portion on the outer surface of the material with a material capable of exciting surface acoustic waves, or at least one spherical shape using a material capable of exciting surface acoustic waves. The outer surface includes a portion that is continuously formed in an annular shape by the portion.

Here, a piezoelectric material is usually used as a material capable of exciting a surface acoustic wave. When the entire surface acoustic wave propagation substrate is formed using a material capable of exciting a surface acoustic wave, a piezoelectric material such as a quartz crystal is used. Piezoelectric crystal materials such as, lithium niobate (LiNbO ₃ ), lithium tantalate (LiTaO ₃ ), langasite (La ₃ Ga ₅ SiO ₁₄ ) and their families are used. In this case, the portion configured continuously in an annular shape by at least a part of the spherical shape is on a line where the crystal plane of the piezoelectric crystal material intersects the outer surface, and is continuous in the annular shape. The direction in which the line extends is the substantially extending direction of the line.

  The surface acoustic wave propagation substrate of piezoelectric crystal material is usually formed into a spherical shape having a diameter of about 10 mm to about 1 mm in consideration of manufacturing costs.

  The surface acoustic wave / excitation / detection means can have various configurations, and so-called interdigital electrodes (also referred to as comb electrodes) are usually used in consideration of manufacturing cost, device size, conversion efficiency, and the like. The

  The interdigital electrode has a shape in which a plurality of comb-shaped electrode branches are alternately arranged in combination with a pair of comb-shaped terminal portions, and at least a part of the spherical shape on the outer surface of the surface acoustic wave propagation substrate. Piezoelectric crystal material is formed directly on the surface of the interdigital electrode support member which is formed directly by, for example, photolithography (photoengraving) on a portion which is continuously formed in an annular shape, or separate from the surface acoustic wave propagation substrate For example, photolithography (photoengraving) is directly formed on the inner surface of a partially spherical recess formed in a shape similar to the above-mentioned portion of the outer surface of the surface of the surface acoustic wave propagation substrate. It arrange | positions through a clearance gap (1/4 or less of the wavelength of the surface acoustic wave to excite).

  Surface acoustic wave propagation of a surface acoustic wave having a wavelength corresponding to the distance between two adjacent comb-shaped electrode branches by applying a high-frequency signal of a predetermined frequency in a burst shape between a pair of comb-shaped terminal portions The above-mentioned portion of the outer surface of the substrate can be excited, and the width of the excited surface acoustic wave corresponds to the length of the portions facing each other in the two comb-like electrode branches adjacent to each other. .

  Further, the wavefront of the surface acoustic wave excited in the direction in which the plurality of comb-shaped electrode branches of the pair of comb-shaped terminal portions of the interdigital electrode are alternately arranged is as described above on the outer surface of the piezoelectric crystal material. It becomes the direction which advances substantially. Therefore, in order to excite the surface acoustic wave by the interdigital electrode on the outer surface of the surface acoustic wave propagation substrate and to propagate the surface acoustic wave in the direction in which the portion continues in an annular shape, A plurality of comb-like electrode branches of the pair of comb-shaped terminal portions of the electrode must be arranged in the above direction.

  For example, as known from International Publication No. WO 01/45255 A1 (Patent Document 2), the curvature of the portion of the outer surface of the surface acoustic wave propagation substrate and the continuous direction of the portion (that is, excited elasticity) The width of the surface acoustic wave to be excited in the direction orthogonal to the surface wave propagation direction (when the surface acoustic wave / excitation / detection means is an interdigital electrode, multiple electrode branches of the interdigital electrode face each other) And the frequency of the surface acoustic wave to be excited in the above part (surface acoustic wave / arrangement period of plural electrode branches of the interdigital electrode when the excitation / detection means is an interdigital electrode) By setting the item to a predetermined condition and exciting the surface acoustic wave in the continuous direction, the excited surface acoustic wave intersects the continuous direction of the portion along the portion of the outer surface. Direction Can be repeatedly circulated without being greatly diffused in the direction.

  The spherical surface acoustic wave device is provided with a sensitive film that is sensitive to changes in the external environment on the portion of the outer surface of the surface acoustic wave propagation substrate (that is, the surface acoustic wave circuit), and an external environment in contact with the sensitive film, for example, a gas Corresponding to the change in concentration, the propagation speed of surface acoustic waves that circulate around the peripheral circuit and the attenuation rate of vibration energy change, and the peripheral circuit obtained by the output from the surface acoustic wave / excitation / detection means bursts. This is used to measure changes in the external environment, for example, gas concentration, using the time required for one round of the surface acoustic wave to change and the phase and intensity of the surface acoustic wave changing with each round. I can do it.

  A phase in a high frequency signal generally means a temporal position of a corresponding signal at a predetermined time when a predetermined time is defined. The phase measurement in the output measurement of the spherical surface acoustic wave element is performed by calculating the time position (phase) of the high-frequency signal output from the spherical surface acoustic wave device at the time when a predetermined time has elapsed from the time when the surface acoustic wave was excited. It is usually used to measure using analysis, quadrature detection, wavelet transform, etc., and the propagation (circulation) velocity of the surface acoustic wave can be directly measured from the measurement. Alternatively, for example, the time when the spherical surface acoustic wave device has finished outputting a predetermined number of times (the time when the predetermined number of laps have been completed) is obtained, and the passage of time from the lap start time to the end time can also be obtained. In this invention, it is not excluded to obtain information on the propagation speed of surface acoustic waves.

  For example, if the gas concentration is increased, the peripheral speed of the burst-like surface acoustic wave that circulates around the peripheral circuit is slowed down by the influence of the change in the sensitive film corresponding to the change in concentration. The time required for the surface acoustic wave to make one round increases. In the same case, there is a delay in the phase of the surface acoustic wave every round, and the strength is reduced.

  Changes in the circumferential speed of the burst-like surface acoustic wave during one round of the circumference circuit due to environmental changes as described above, and changes in the time required for the burst-like surface acoustic wave to make one round in the circumference circuit In addition, the phase delay of the surface acoustic wave every round and the decrease in strength are small, but these changes are superimposed as the number of times the surface acoustic wave circulates around the circuit increases. It gets bigger. That is, the measurement accuracy of the change is improved.

  Therefore, when measuring the change in the external environment using the spherical surface acoustic wave device as described above, the attenuation factor of the vibration energy of the surface acoustic wave that circulates in the peripheral circuit is caused by factors other than the change in the external environment. Obviously, it is not desirable to decrease.

  When the interdigital electrode is used as a known surface acoustic wave / excitation / detection means in the spherical surface acoustic wave device, the interdigital electrode is placed on the above-mentioned portion (ie, the surface acoustic wave circuit) as in the former case. When directly formed, the surface acoustic wave that is excited by the interdigital electrode to the portion of the outer surface of the piezoelectric crystal material and propagates in the continuous direction of the portion circulates along the peripheral circuit of the portion of the outer surface. In the meantime, it is affected by reflection and phase change due to the mass of the interdigital electrode, and a signal waveform is squeezed or vibration energy is lost each time.

This means that when a comb-like electrode is used as a known surface acoustic wave / excitation / detection means in a spherical surface acoustic wave device, the surface acoustic wave propagation substrate of the piezoelectric crystal material is the same as the latter case described above. The interdigital electrode is elastically formed after the interdigital electrode is directly formed on the inner surface of a partially spherical recess formed on the surface of a separate interdigital electrode support member in a shape similar to the above-mentioned portion of the outer surface of the piezoelectric crystal material. It means that it is preferable to arrange the surface wave propagation base so as to face the above-mentioned portion of the outer surface of the surface wave propagation substrate with a predetermined gap.
JP 2005-94609 A International Publication WO 01/45255 A1

  However, as described above, the diameter of the sphere of the surface acoustic wave propagation substrate is usually as small as 10 mm to 1 mm, so that the partially spherical concave formed on the surface of the interdigital electrode support member separate from the surface acoustic wave propagation substrate. The interdigital electrode formed on the inner surface of the electrode is disposed so as to face the above-mentioned portion of the outer surface of the piezoelectric crystal material through the aforementioned predetermined gap (1/4 or less of the wavelength of the excited surface acoustic wave). The work to be performed is complicated and requires a lot of time.

  If the gap is not predetermined, the interdigital electrode cannot excite a surface acoustic wave having a predetermined strength to the circumferential circuit of the surface acoustic wave propagation substrate, and consequently the surface acoustic wave that circulates the circumferential circuit. The intensity and phase cannot be detected accurately.

  The present invention has been made under the circumstances described above, and the object of the present invention is to simplify the structure and easy to manufacture, reduce the time spent for manufacturing, and to excite the peripheral circuit of the surface acoustic wave propagation substrate. An object of the present invention is to provide a spherical surface acoustic wave device that can accurately detect the intensity and phase of a surface acoustic wave that has circulated around the circumference circuit, in spite of the ease of manufacture.

  In order to achieve the above-described object of the present invention, a spherical surface acoustic wave device according to the present invention comprises: an annular surface continuously configured by at least a part of a sphere, so that the surface acoustic wave can be excited and excited. A surface acoustic wave propagation substrate including a surface acoustic wave circuit capable of propagating and circulating in the direction in which the annular surface is continuous; and the surface acoustic wave circumference on the outer surface of the surface acoustic wave propagation substrate. A substrate support for supporting a region excluding the circuit; and an elastically deformable elastic deformation member supporting the surface acoustic wave / excitation / detection means, and supporting the surface acoustic wave / excitation via the elastic deformation member. / Exciting / detecting means / support for elastically deforming the elastic deformable member while bringing the detecting means into contact with the surface acoustic wave circuit on the outer surface of the surface acoustic wave propagation substrate.

  The spherical surface acoustic wave device according to the present invention, which is configured as described above, has a simple configuration as described above. In addition, the surface acoustic wave / excitation / detection means is supported by the excitation / detection means / support via an elastic deformation member, and the surface acoustic wave propagation base is supported by the excitation / detection means / support via the elastic deformation member. Are in contact with the surface acoustic wave circuit on the outer surface. Accordingly, since complicated positioning of the surface acoustic wave / excitation / detection means with respect to the surface acoustic wave circuit on the outer surface of the surface acoustic wave propagation substrate is unnecessary, the time spent for manufacturing can be shortened.

  The surface acoustic wave / excitation / detection means that is in contact with the surface acoustic wave peripheral circuit via the elastic deformation member by the excitation / detection means / support is the surface acoustic wave on the outer surface of the surface acoustic wave propagation substrate. Compared to a case where the circuit is arranged at a predetermined distance from the peripheral circuit (1/4 or less of the wavelength of the surface acoustic wave excited and circulated by the surface acoustic wave circuit), the peripheral circuit of the surface acoustic wave propagation substrate is excited by the peripheral circuit. Although the strength and phase of the surface acoustic wave that circulates the circuit cannot be detected accurately, the surface acoustic wave is compared with the case where it is formed in the surface acoustic wave peripheral circuit on the outer surface of the surface acoustic wave propagation substrate. It is possible to detect the intensity attenuation and propagation (circulation) speed associated with the orbit of the object more precisely.

[First Embodiment]
A spherical surface acoustic wave device 10 according to a first embodiment of the present invention will be described below with reference to FIGS. 1 to 7 in the accompanying drawings.

  The spherical surface acoustic wave device 10 includes a surface acoustic wave propagation base 12. The surface acoustic wave propagation base 12 is formed using a material that cannot excite a surface acoustic wave so that the outer surface includes at least a part that is continuously formed in an annular shape by a part of a spherical shape. It is formed by coating at least the annular portion on the outer surface of the base material with a material capable of exciting surface acoustic waves, or at least a spherical shape using a material capable of exciting surface acoustic waves. The outer surface includes a part that is continuously formed in an annular shape by a part.

  In this embodiment, the surface acoustic wave propagation substrate 12 is formed in a spherical shape by a material capable of exciting surface acoustic waves, and is continuously formed in an annular shape by at least a part of the spherical shape. The surface acoustic wave circuit 12a that can be excited and propagates in the direction in which the annular ring continues and can circulate is included on the outer surface.

Examples of materials that can excite surface acoustic waves include quartz, lithium niobate (LiNbO ₃ ), lithium tantalate (LiTaO ₃ ), langasite (La ₃ Ga ₅ SiO ₁₄ ), and piezoelectric crystal materials such as these families. Is used. In this case, the portion configured continuously in an annular shape by at least a part of the spherical shape is on a line where the crystal plane of the piezoelectric crystal material intersects the outer surface, and is continuous in the annular shape. The direction in which the line extends is the substantially extending direction of the line.

  The surface acoustic wave propagation base 12 made of piezoelectric crystal material is usually formed into a spherical shape having a diameter of about 10 mm to about 1 mm in consideration of the manufacturing cost, but the surface acoustic wave propagation according to this embodiment is performed. The diameter of the substrate 12 is 3.3 mm.

  In this embodiment, the surface acoustic wave propagation base 12 is formed of a spherical crystal. Quartz crystal has a crystal axis Z (C axis in the case of quartz crystal) that corresponds to the equator when the crystal axis Z is viewed as the rotation axis of the earth. The surface acoustic wave propagation path 12a is a line that intersects the surface, and substantially circles the outer surface along the maximum outer circumferential line.

  The spherical surface acoustic wave device 10 supports a substrate support 14 that supports a region excluding the surface acoustic wave circuit 12a on the outer surface of the surface acoustic wave propagation substrate 12, and a surface acoustic wave / excitation / detection means 16. The elastically deformable elastic deformation member 18 is supported, and the surface acoustic wave / excitation / detection means 16 is brought into contact with the surface acoustic wave circuit 12 a on the outer surface of the surface acoustic wave propagation base 12 via the elastic deformation member 18. Excitation / detection means / support 20 for elastically deforming the elastic deformation member 18 is further provided.

  In this embodiment, the base body support 14 includes a base end portion 14a supported by the base 22 and an extended end portion 14b extending in a direction away from the base 22, and with respect to the base end portion 14a. The extending end portion 14b can be bent elastically. The base support 14 can be formed of an elastically bendable material as described above. In this embodiment, the base support 14 is formed of a stainless steel plate having a thickness of 0.04 mm. The base end portion 14a of the substrate support 14 is fixed to the base 22 by known fixing means including solder, fixing screws, rivets, and an adhesive.

  The extended end portion 14 b of the substrate support 14 is configured to support a region on the outer surface of the surface acoustic wave propagation substrate 12 excluding the surface acoustic wave circuit 12 a.

  In this embodiment, the excitation / detection means / support 20 includes a base end 20 a supported by the base 22 and an extended end 20 b extending in a direction away from the base 22. The extended end portion 20b can be elastically bent with respect to the portion 20a. The excitation / detection means / support 20 can also be formed of an elastically bendable material as described above, and is formed of a stainless steel plate having a thickness of 0.04 mm in this embodiment. The base end portion 20a of the excitation / detection means / support 20 is fixed to the base 22 by known fixing means 24 including solder, fixing screws, rivets and adhesive.

  The extension end 20b of the excitation / detection means / support 20 supports the elastic deformation member 18 and faces the extension end 14b of the substrate support 14 with the surface acoustic wave propagation substrate 12 interposed therebetween. A surface acoustic wave / excitation / detection means 16 is brought into contact with the surface acoustic wave circuit 12a on the outer surface of the surface acoustic wave propagation substrate 12 as shown in FIG.

  Accordingly, the surface acoustic wave propagation base 12 is elastically held away from the base 22 by the extended end 14 a of the base support 14 and the extended end of the excitation / detection means / support 20.

  In this embodiment, the elastically deformable member 18 is formed of a non-conductive rubber, but can be formed of a viscoelastic material as long as the elastic deformation condition described later is satisfied. It can also be formed of a material that hardens together.

  In this embodiment, the surface acoustic wave / excitation / detection means 16 is provided by an interdigital electrode. As shown in FIGS. 3A and 3B, the interdigital electrode is formed by combining a pair of comb-shaped terminal portions 16a and 16b by alternately arranging a plurality of comb-shaped electrode branches 16c. A pair of combs of interdigital electrodes when they are in contact with the surface acoustic wave circuit 12a via the elastic deformation member 18 by the extended end 20b of the excitation / detection means / support 20. The direction in which the plurality of comb-like electrode branches 16c of the shape terminal portions 16a and 16b are alternately arranged extends in a ring shape of the surface acoustic wave circuit 12a (in this embodiment, surface acoustic wave propagation by quartz crystal The crystal plane around the crystal axis Z of the crystal on the outer surface of the substrate 12 coincides with a direction along an annular line intersecting the outer surface), and preferably each of the plurality of comb-like electrode branches 16c extends. The direction extends in an annular shape of the surface acoustic wave circuit 12a. So as to be orthogonal to the direction (in this embodiment, the crystal plane around the crystal axis Z of the crystal on the outer surface of the surface acoustic wave propagation substrate 12 made of quartz intersects the outer surface). Further, it is formed on the surface of the elastic deformation member 18.

  The interdigital electrode is formed by, for example, photolithography (photoengraving) after directly forming a highly conductive metal thin film such as gold, copper, or aluminum on the surface of the elastic deformation member 18 formed of non-conductive rubber. It can be formed by molding. However, when the elastic deformation member 18 is brought into contact with the surface acoustic wave circuit 12a, its surface is slightly stretched when it is elastically deformed, and the interdigital electrode may be broken by this stretching. For this reason, as described above on a non-conductive material such as a ceramic thin film that can be deformed together with the outer surface of the elastic deformation member 18 along with the elastic deformation of the elastic deformation member 18 but does not extend as much as the outer surface of the elastic deformation member 18. It is preferable to form an interdigital electrode. In other words, the interdigital electrode is preferably formed as described above on the non-conductor interposed between the surface acoustic wave / excitation / detection means 16 and the elastic deformation member 18 provided by the interdigital electrode.

  Such a non-conductor can be supported on the outer surface of the elastic deformation member 18 by a known supporting means including an adhesive before the interdigital electrode is formed, or the interdigital electrode is formed. Then, it may be supported on the outer surface of the elastic deformation member 18 by a known support means including, for example, an adhesive.

  The pair of comb-shaped terminal portions 16a and 16b of the interdigital electrode operates the surface acoustic wave / excitation / detection means 16 via the elastic deformation member 18 and the wiring (not shown) arranged on the excitation / detection means / support 20. Is electrically connected to known operation control means for controlling the motor.

  The interdigital electrode of the surface acoustic wave / excitation / detection means 16 is passed through the elastic deformation member 18 by the extended end portion 20b of the excitation / detection means / support 20 as shown in FIG. A high-frequency signal having a predetermined frequency is applied in a burst manner between the pair of comb-shaped terminal portions 16a and 16b while being in contact with the twelve surface acoustic wave propagation paths 12a. Thus, a surface acoustic wave having a predetermined wavelength can be excited by the surface acoustic wave circuit 12a on the outer surface of the surface acoustic wave propagation substrate 12. Here, the wavelength of the predetermined frequency and the predetermined wavelength correspond to the distance (arrangement period) P between the two comb-like electrode branches 16c adjacent to each other.

  The width of the surface acoustic wave excited by the interdigital transducer 12a is the distance at which the plurality of comb-shaped electrode branches 16c of the pair of comb-shaped terminal portions 16a and 16b of the interdigital electrode face each other (electrode width). ) W.

  In FIG. 3B, each of the pair of comb-shaped terminal portions 16a and 16b is constituted by four comb-shaped electrode branches 16c, but each of the pair of comb-shaped terminal portions 16a and 16b has only one. Even if it is constituted by the comb-like electrode branch 16c, it is possible to excite and detect the surface acoustic wave, and the present invention does not exclude it. In addition, the interdigital electrode which excites a surface acoustic wave only in one direction and the interdigital electrode of the special structure which excites a some frequency efficiently are well-known, and any of these can use this invention.

  In order to excite the surface acoustic wave of a predetermined wavelength to the surface acoustic wave circuit 12a on the outer surface of the surface acoustic wave propagation substrate 12 under the same conditions at all times, the extension / extension end 20b of the excitation / detection means / support 20 is elastic. While the interdigital electrode of the surface acoustic wave / excitation / detection means 16 is in contact with the surface acoustic wave propagation path 12a of the surface acoustic wave propagation base 12 as shown in FIG. The entire distance W at which the plurality of comb-like electrode branches 16c of the pair of comb-shaped terminal portions 16a and 16b of the interdigital electrode face each other must always be in contact with the surface acoustic wave circuit 12a.

  In order to satisfy this condition, as shown in FIG. 4, the elastic deformation member 18 on the extended end portion 20b of the excitation / detection means / support 20 causes the surface acoustic wave / excitation / detection means 16 to move to the elastic surface. The depth D of the recess of the elastic deformation member 18 when it is brought into contact with the surface acoustic wave circuit 12a on the outer surface of the wave propagation substrate 12 may be as follows.

D = R (1-cos (W / 2R))
Here, W / 2R in parentheses following cos is in radians, W is the electrode width of the interdigital electrode, and R is the radius of the surface acoustic wave circuit 12a of the surface acoustic wave propagation substrate 12.

  That is, the elasticity of the excitation / detection means / support 20 and the elastic deformation member 10 is set so that at least the depth D of the elastic deformation member 18 is obtained. However, if there is no possibility that the interdigital electrode of the surface acoustic wave / excitation / detection means 16 breaks from the recess of the elastic deformation member 18 as described above, the depth D may be deeper.

  Alternatively, if the outer surface of the elastic deformation member 10 on which the interdigital electrode of the surface acoustic wave / excitation / detection means 16 is supported has been processed into a concave surface having a depression as described above, the surface acoustic wave propagation substrate 12 When the interdigital electrode of the surface acoustic wave / excitation / detection means 16 is brought into contact with the surface acoustic wave circuit 12a, the amount of elastic deformation imposed on the outer surface of the elastic deformation member 10 is almost eliminated. The possibility that the interdigital electrode of the detection means 16 is broken is almost eliminated.

  However, when the outer surface of the elastically deformable member 10 has a planar shape, a photolithographic technique (photoengraving) or mask is formed from a highly conductive metal thin film such as gold, copper, or aluminum in which interdigital electrodes are formed on the outer surface. If it is formed using a less exposure machine, a higher definition interdigital electrode can be formed at a low cost. That is, process apparatuses such as an exposure apparatus and an ink jet coating apparatus that are widely used for high-definition patterning are manufactured on the assumption that the object to be patterned is a flat surface.

  If a surface acoustic wave having a predetermined range of width and a predetermined wavelength is excited with respect to the radius of the surface acoustic wave circuit 12a, the surface acoustic wave circuit 12a diffuses along the surface acoustic wave circuit 12a in a direction intersecting with the extension direction. It is known from Patent Document 2 described above that the surface acoustic wave can be repeatedly circulated without any problems.

  The above-mentioned known operation control means applies the surface acoustic wave that circulates the surface acoustic wave circuit 12a to the surface acoustic wave circuit 12a as described above, the excitation / detection means, the extended end 20b of the support 20 and the elastic deformation. It can be detected by the interdigital electrode of the surface acoustic wave / excitation / detection means 16 abutted through the member 10.

  In this way, the interdigital electrode of the surface acoustic wave / excitation / detection means 16 that is in contact with the surface acoustic wave circuit 12a by the excitation / detection means / support 20 via the elastic deformation member 18 is the surface acoustic wave. Since some of the energy of the surface acoustic wave that has circulated around the circumferential circuit 12a is reflected and the surface acoustic wave is somewhat attenuated, the surface acoustic wave peripheral circuit 12a on the outer surface of the surface acoustic wave propagation base 12 has a predetermined value. The surface acoustic wave circuit 12a of the surface acoustic wave propagation substrate 12 is excited by the surface acoustic wave surface compared to the case where the distance is ¼ or less of the wavelength of the surface acoustic wave excited and circulated by the surface acoustic wave circuit 12a. Although it is not possible to accurately detect the intensity and phase of the surface acoustic wave that circulates the wave circuit 12 a, compared to the case where the surface wave wave circuit 12 a is formed on the outer surface of the surface acoustic wave propagation substrate 12. Surface acoustic wave circumference Ratio for attenuating affect the road 12a to the propagation of the surface acoustic wave obtained by circulating reflects the energy can be more accurately detect the small surface acoustic wave intensity and phase.

  This is because the interdigital electrode of the surface acoustic wave / excitation / detection means 16 is usually formed as compared with the surface roughness of the outer surface of the surface acoustic wave propagation substrate 12 obtained by processing the piezoelectric crystal material. The surface roughness of the outer surface of the metal thin film is large. When viewed microscopically, the interdigital electrode of the surface acoustic wave / excitation / detection means 16 is compared with the surface acoustic wave circuit 12a on the outer surface of the surface acoustic wave propagation substrate 12. This is because there are countless point contacts.

  However, the surface area of the peripheral circuit contact portion where the interdigital electrode of the surface acoustic wave / excitation / detection means 16 contacts the surface acoustic wave circuit 12a is smaller, so that the energy of the surface acoustic wave is reflected. This is preferable because the rate of attenuation is small.

  For this reason, in this embodiment, the interdigital electrode of the surface acoustic wave / excitation / detection means 16 is better in FIG. 5 than the surface of the peripheral circuit contact portion where the interdigital electrode contacts the surface acoustic wave circuit 12a. As shown, a contact area reduction process 26 for reducing the contact area with the surface acoustic wave circuit 12a is applied. The contact area reduction process 26 includes forming concave portions or convex portions at a plurality of locations on the surface of the peripheral circuit contact portion of the surface acoustic wave / excitation / detection means 16.

  The plurality of recesses of the contact area reduction process 26 are formed by etching, for example. Specifically, as shown in FIGS. 6A and 6B, the surface acoustic wave / excitation / detection means 16 (on the outer surface of the elastically deformable member 18 (see FIG. 2), which is a nonconductor, is provided. 2), a plurality of minute resist patterns LP are adhered to the metal thin film MF formed directly or indirectly through a non-conductor not shown as described above. Next, as shown in FIG. 6C, known isotropic etching is performed on the metal thin film MF with a plurality of minute resist patterns LP. Thereby, concave portions are formed at a plurality of locations on the outer surface of the metal thin film MF that is not covered with the plurality of minute resist patterns LP. Next, as shown in FIG. 6D, a plurality of minute resist patterns LP are removed from the outer surface of the metal thin film MF by a known method. Thereafter, in order to further reduce the area of the apex of the protrusions between the concave portions at the plurality of locations on the outer surface of the metal thin film MF (which is a portion that directly contacts the surface acoustic wave circuit 12a), A known isotropic etching can be performed again on the outer surface.

  The plurality of recesses of the contact area reduction process 26 are also formed on the outer surface of the elastic deformation member 18 (see FIG. 2) for forming interdigital electrodes of the surface acoustic wave / excitation / detection means 16 (see FIG. 2). As described above, a known soft etching is performed on the outer surface of the metal thin film MF formed directly or indirectly through a nonconductor (not shown) without attaching a plurality of minute resist patterns LP. It can also be obtained by generating etching spots on the outer surface of the thin film MF.

  For example, as shown in FIG. 7, the plurality of convex portions of the contact area reducing process 26 are not directly or non-illustrated on the outer surface of the elastic deformation member 18 (see FIG. 2). A plurality of electrode branches 16c (FIG. 3) of the interdigital electrode with respect to the outer surface of the interdigital electrode of the surface acoustic wave / excitation / detection means 16 (see FIG. 2) formed from a thin metal film indirectly formed The fine particles MP having a diameter equal to or less than ¼ of the arrangement period P of (B) of FIG. 5B are attached to a plurality of locations on the surface of the peripheral circuit contact portion of the surface acoustic wave / excitation / detection means 16. can do.

[Second Embodiment]
Hereinafter, a spherical surface acoustic wave device 30 according to a second embodiment of the present invention will be described with reference to FIG. 8 in the accompanying drawings.

  Part of the constituent members of the spherical surface acoustic wave device 30 according to the second embodiment is a spherical surface acoustic wave according to the first embodiment of the present invention described above with reference to FIGS. This is the same as some of the components of the device 10. Therefore, in the spherical surface acoustic wave device 30 according to the second embodiment, the same components as those of the spherical surface acoustic wave device 10 according to the first embodiment described above are used in the first embodiment. The same reference numerals as those used for the corresponding components of the spherical surface acoustic wave device 10 according to FIG.

  The spherical surface acoustic wave device 30 according to the second embodiment is different from the spherical surface acoustic wave device 10 according to the first embodiment in that the surface of the surface acoustic wave propagation base 12 is an elastic surface. The structure of the substrate support 32 that supports the region excluding the wave circuit 12a and the elastically deformable elastic deformation member 18 'supporting the surface acoustic wave / excitation / detection means 16 are supported and the elastic deformation member 18' is supported. Excitation / detection means / support for bringing the surface acoustic wave / excitation / detection means 16 into contact with the surface acoustic wave circuit 12a on the outer surface of the surface acoustic wave propagation substrate 12 and elastically deforming the elastic deformation member 18 ' 34 configuration.

  As shown well in FIG. 8A, the substrate support 32 is formed of a plurality of surface acoustic wave propagation substrates 12 and a surface acoustic wave circuit 12a on the outer surface of each of the plurality of surface acoustic wave propagation substrates 12. A part of the substrate is exposed from one surface of the substrate support 32 and supported.

  In this embodiment, the substrate support 32 has a flat plate shape, and the plurality of predetermined support locations 32 a have a hole shape penetrating both planes of the substrate support 32. In each support location 32a, a surface acoustic wave propagation substrate 12 whose orientation of the crystal axis Z is known by a known measuring means and the position of a predetermined surface acoustic wave circuit 12a on the outer surface can be measured is, for example, a known holding As described above, the surface acoustic wave circuit 12a is transported from the place where the predetermined surface acoustic wave circuit 12a is measured to the predetermined support place 32a of the substrate support 32 and supported by the predetermined support place 32a while being temporarily held by the transport means 36.

  The surface acoustic wave propagation base 12 with respect to the predetermined support location 32a has a crystal axis Z (C axis in the case of quartz) directed in a predetermined direction, that is, a predetermined elasticity of the outer surface of the surface acoustic wave propagation base 12. The surface wave circuit 12a is supported toward a predetermined circumferential position around the hole of the predetermined support location 32a. At that time, the predetermined surface acoustic wave circuit 12a on the outer surface of the surface acoustic wave propagation base 12 is in contact with both planes of the plate-shaped base support 32 at a predetermined circumferential position of a hole of a predetermined support location 32a. Orthogonal.

  A region other than the predetermined surface acoustic wave circuit 12a on the outer surface of the surface acoustic wave propagation substrate 12 is supported by a predetermined support location 32a, and the predetermined surface acoustic wave circuit 12a is not in contact with the predetermined support location 32a. A known fixing means such as an adhesive is provided in an area of the predetermined support location 32a that supports an area other than the predetermined surface acoustic wave circuit 12a on the outer surface of the surface acoustic wave propagation base 12. Accordingly, the outer surface of the surface acoustic wave propagation base 12 supported by the predetermined support location 32a is fixed to the predetermined support location 32a by the known fixing means described above.

  Further, at a predetermined support location 32a of the substrate support 32, both ends in the radial direction are exposed to the external space in a predetermined surface acoustic wave circuit 12a on the outer surface of the surface acoustic wave propagation substrate 12.

  The excitation / detection means / support 34 of this embodiment is detachably fixed to a predetermined position on one surface of the substrate support 32 as shown in FIGS. 8B and 8C. Thus, a part of the surface acoustic wave circuit 12a on the outer surface of the plurality of surface acoustic wave propagation substrates 12 supported on the plurality of predetermined support locations 32a of the substrate support 32 as described above is brought into contact and elastically deformed. The elastic deformation member 36 is provided. The elastic deformation member 36 can be formed of the same material as the elastic deformation member 18 of the first embodiment described above.

  Further, a part of the surface acoustic wave circuit 12a on the outer surface of the plurality of surface acoustic wave propagation substrates 12 supported by the elastic deformation member 36 at the plurality of predetermined support locations 32a of the substrate support 32 as described above is applied. The interdigital electrodes of the surface acoustic wave / excitation / detection means 16 are supported on each of the plurality of portions in contact with each other as in the case of the first embodiment described above.

  Excitation / detection means is provided on a part of the surface acoustic wave circuit 12a on the outer surface of each of the plurality of surface acoustic wave propagation substrates 12 supported as described above at a plurality of predetermined support locations 32a of the substrate support 32. The interdigital electrode of the surface acoustic wave / excitation / detection means 16 abutted through the elastic deformation member 36 of the support 34 has a plurality of comb teeth as in the case of the first embodiment described above. The direction in which the electrode-like electrode branches 16c (see FIGS. 3A and 3B) are alternately arranged extends in a ring shape of the surface acoustic wave circuit 12a (in this embodiment, the elasticity of crystal In the outer surface of the surface wave propagation substrate 12, the crystal plane around the crystal axis Z of the crystal coincides with a direction along an annular line intersecting with the outer surface, and preferably each of the plurality of comb-like electrode branches 16c. The extending direction of the surface is an annular shape of the surface acoustic wave circuit 12a. Orthogonal to the exit direction (in this embodiment, the crystal plane around the crystal axis Z of the quartz crystal on the outer surface of the surface acoustic wave propagation substrate 12 made of quartz intersects the outer surface). As described above, the elastic deformation member 36 is formed on the plurality of predetermined portions on the outer surface.

  As shown in FIGS. 8B and 8C, the structure for detachably fixing the excitation / detection means / support 34 to a predetermined position on one surface of the substrate support 32 is shown. Various known positioning and fixing structures can be employed. In this embodiment, a plurality of positioning holes PH formed at a plurality of predetermined positions on one surface of the substrate support 32 and a plurality of positioning holes PH at a plurality of predetermined positions on the outer surface of the excitation / detection means / support 34 are provided. A combination of a plurality of positioning protrusions PP formed so as to be detachable from the positioning hole PH provides the positioning fixing structure.

  A plurality of positioning holes PH are formed at a plurality of predetermined positions on the outer surface of the excitation / detection means / support 34, and a plurality of positioning projections PP are formed at a plurality of predetermined positions on one surface of the substrate support 32. You can also.

FIG. 1 shows a spherical surface acoustic wave device according to a first embodiment of the present invention, in which a region excluding a surface acoustic wave circuit on the outer surface of a spherical surface acoustic wave propagation substrate is an extension of a substrate support. The surface acoustic wave / excitation / detection means is brought into contact with the surface acoustic wave circuit by the extension end of the excitation / detection means / support through the elastic deformation member while being supported by the extension end portion. It is a side view which shows the state immediately before. FIG. 2 shows the spherical surface acoustic wave device of FIG. 1 while the region excluding the surface acoustic wave circuit on the outer surface of the spherical surface acoustic wave propagation substrate is supported by the extended end of the substrate support. In addition, the surface acoustic wave propagation base is brought into contact with the surface acoustic wave circuit by bringing the surface acoustic wave / excitation / detection means into contact with the extending end of the excitation / detection means / support through the elastic deformation member. FIG. 6 is a side view schematically showing a state in which the extended end of the support and the excitation / detection means / the extended end of the support are elastically clamped away from the base. FIG. 3A shows the surface acoustic wave circuit on the outer surface of the surface acoustic wave propagation substrate shown in FIG. 2, in which the surface acoustic wave / excitation / detection means is connected to the excitation / detection means / support via an elastic deformation member. FIG. 3 is a view schematically showing a state in which the extended end portion is in contact with the elastic deformable member and the extended end portion of the excitation / detection means / support; FIG. It is a figure which expands and shows the comb-shaped electrode as a surface acoustic wave and an excitation / detection means. FIG. 4 shows the surface acoustic wave circuit on the outer surface of the spherical surface acoustic wave propagation substrate in FIG. 2. The surface acoustic wave / excitation / detection means is extended through the elastic deformation member to the excitation / detection means / support. It is a schematic top view which shows the grade of the preferable elastic deformation of an elastic deformation member when it contact | abuts by the edge part. FIG. 5 shows the surface acoustic wave circuit on the outer surface of the surface acoustic wave propagation substrate of FIG. 2 in which the surface acoustic wave / excitation / detection means is extended through an elastic deformation member. 5 is a side view schematically showing an enlarged surface of the surface acoustic wave / excitation / detection means, an elastic deformation member, and an extension end of the excitation / detection means / support. 6A shows a metal that is the basis of the surface acoustic wave / excitation / detection means in order to perform contact area reduction processing applied to the surface of the surface acoustic wave / excitation / detection means of FIG. 5 by etching. FIG. 6 (B) is a schematic side view of FIG. 6 (A); and FIG. 6 (C) and FIG. 6D schematically shows a state in which etching progresses from FIG. 6B and a plurality of recesses are formed on the surface of the surface acoustic wave / excitation / detection means in FIG. Is a side view showing; 7 shows a state in which a plurality of fine particles are applied to the surface of the surface acoustic wave / excitation / detection means in order to reduce the contact area applied to the surface of the surface acoustic wave / excitation / detection means in FIG. It is a side view which expands and shows roughly. FIG. 8A shows a surface acoustic wave device according to a second embodiment of the present invention, in which a plurality of spherical surface acoustic wave propagation bases are surface acoustic waves on their outer surfaces by a base support. FIG. 8B is a longitudinal sectional view schematically showing a state in which a part of the peripheral circuit is exposed and supported from one surface of the substrate support; FIG. 8B is the substrate of FIG. A longitudinal section schematically showing a state immediately before the excitation / detection means / support of the spherical surface acoustic wave device according to the second embodiment of the present invention is detachably fixed to a predetermined position on one surface of the support FIG. 8C shows that the excitation / detection means / support of FIG. 5B can be attached to and detached from a predetermined position on one surface of the substrate support of FIG. 5B. Part of the surface acoustic wave circuit on the outer surface of the plurality of surface acoustic wave propagation substrates supported by the substrate support by being fixed FIG. 6 is a longitudinal sectional view schematically showing a state where the elastic deformation member of the excitation / detection means and the support body is elastically deformed by contacting the excitation / detection means.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Spherical surface acoustic wave apparatus, 12 ... Surface acoustic wave propagation base | substrate, 12a ... Surface acoustic wave circuit, 14 ... Base | substrate support body, 14a ... Base end part, 14b ... Extension end part, 16 ... Surface acoustic wave and excitation / Detecting means, 16a, 16b ... comb-shaped terminal, 16c ... comb-like electrode branch, 18 ... elastically deforming member, 20 ... excitation / detecting means / support, 20a ... proximal end, 20b ... extended end, 22: Base, 24: Fixing means, P: Arrangement period, W: Electrode width, D: Depth of recess, R: Radius, 26: Abutting area reduction processing, LP: Resist pattern, MF: Metal thin film, 30 DESCRIPTION OF SYMBOLS ... Spherical surface acoustic wave apparatus, 32 ... Base | substrate support body, 32a ... Support place, 34 ... Excitation / detection means and support body, 36 ... Elastic deformation member, PH ... Positioning hole, PP ... Positioning protrusion.

Claims (12)

A surface acoustic wave circuit that is formed continuously in an annular shape by at least a part of a spherical shape and can excite surface acoustic waves, and the excited surface acoustic waves can propagate and circulate in the continuous direction of the ring. A surface acoustic wave propagation substrate included on the outer surface;
A substrate support for supporting a region excluding the surface acoustic wave circuit on the outer surface of the surface acoustic wave propagation substrate; and
An elastically deformable elastic deformation member supporting the surface acoustic wave / excitation / detection means is supported, and the surface acoustic wave / excitation / detection means is supported on the outer surface of the surface acoustic wave propagation substrate via the elastic deformation member. An excitation / detection means / support for contacting the surface acoustic wave circuit and elastically deforming the elastically deformable member;
A spherical surface acoustic wave device comprising:   In the surface acoustic wave / excitation / detection means, the surface of the peripheral circuit contact portion that contacts the surface acoustic wave circuit on the outer surface of the surface acoustic wave propagation substrate reduces the contact area with the surface acoustic wave circuit. 2. The spherical surface acoustic wave device according to claim 1, wherein a contact area reduction process is applied.   3. The spherical surface acoustic wave device according to claim 1, wherein the surface acoustic wave / excitation / detection means is a comb-like electrode.   4. The contact area reduction processing includes forming concave or convex portions at a plurality of locations on the surface of the peripheral circuit contact portion of the surface acoustic wave / excitation / detection means. Spherical surface acoustic wave device.   The spherical surface acoustic wave device according to claim 4, wherein the concave portion is formed by etching.   The surface acoustic wave / excitation / detection means is an interdigital electrode, and the convex portion is a surface acoustic wave / excitation / excitation / microparticle having a diameter of 1/4 or less of the arrangement period of the plurality of electrode branches of the interdigital electrode. 5. The spherical surface acoustic wave device according to claim 4, wherein the spherical surface acoustic wave element is formed by adhering to a plurality of locations on the surface of the peripheral circuit contact portion of the detecting means. The surface acoustic wave / excitation / detection means is an interdigital electrode, the electrode width of the interdigital electrode is W, the radius of the surface acoustic wave circuit of the surface acoustic wave propagation substrate is R, and the excitation / detection means / support The depth D of the dent of the elastic deformation member when the surface acoustic wave excitation / detection means is brought into contact with the surface acoustic wave circuit on the outer surface of the surface acoustic wave propagation substrate,
D = R (1-cos (W / 2R)): where the parentheses following cos are in radians,
The spherical surface acoustic wave device according to any one of claims 1 to 6, wherein the surface acoustic wave device is as described above.   8. The elastic deformation member of the excitation / detection means / support is a non-conductor, and the surface acoustic wave / excitation / detection means is formed on the elastic deformation member. The spherical surface acoustic wave device according to Item.     A non-conductor is interposed between the elastic deformation member of the excitation / detection means / support and the surface acoustic wave / excitation / detection means, and the surface acoustic wave / excitation / detection means is formed on the non-conductor. The spherical surface acoustic wave device according to any one of claims 1 to 8, wherein: Each of the substrate support and the excitation / detection means / support includes a base end supported by the base and an extended end extending in a direction away from the base, and extends to the base end. The end is elastically bendable,
The extended end portion of the substrate support supports a region excluding the surface acoustic wave circuit on the outer surface of the surface acoustic wave propagation substrate,
The extension end of the excitation / detection means / support supports the elastic deformation member and faces the extension end of the substrate support with the surface acoustic wave propagation substrate sandwiched therebetween. The surface acoustic wave / excitation / detection means is in contact with the surface acoustic wave circuit on the outer surface,
The surface acoustic wave propagation substrate is elastically held away from the base by the extended end portion of the substrate support and the extended end portion of the excitation / detection means / support.
The spherical surface acoustic wave device according to claim 1, wherein the spherical surface acoustic wave device is provided. The substrate support supports the surface acoustic wave propagation substrate by exposing a part of the surface acoustic wave circuit on the outer surface of the surface acoustic wave propagation substrate to the outside from one surface of the substrate support, and
The excitation / detection means / support is fixed to a predetermined position on one surface of the substrate support, thereby allowing the surface acoustic wave / excitation / detection means to be attached to the outer surface of the surface acoustic wave propagation substrate via the elastic deformation member. Abutting on the part of the surface acoustic wave circuit and elastically deforming the elastic deformation member;
The spherical surface acoustic wave device according to claim 1, wherein the spherical surface acoustic wave device is provided. The substrate support supports a plurality of surface acoustic wave propagation substrates by exposing a part of the surface acoustic wave circuit on the outer surface of each of the plurality of surface acoustic wave propagation substrates from one surface of the substrate support to the outside. And
The excitation / detection means / support is fixed at a predetermined position on one surface of the substrate support, so that the surface acoustic wave periphery of the outer surface of the plurality of surface acoustic wave propagation substrates supported by the substrate support is obtained. An elastic deformation member that is brought into contact with a part of the circuit and elastically deformed;
The spherical surface acoustic wave device according to claim 11.

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