JP2012235925A - Ultrasonic transducer, manufacturing method for ultrasonic transducer, and ultrasonic endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic transducer capable of broadening the frequency band of emitted ultrasonic waves in a simple and damage proof structure.SOLUTION: The ultrasonic transducer is characterized by including a piezoelectric element 1, an upper electrode 2, an acoustic matching layer 4, a lower electrode 3, an added member 7 including a plurality of columnar parts 7c with the same acoustic impedance not more than that of the piezoelectric element 1 and not less than that of the acoustic matching layer 4, which are arranged at predetermined intervals in a width direction X, a filling material 8 loaded between the plurality of the columnar parts 7c and more flexible than the columnar parts 7c, and a backing material 9.

Description

  The present invention relates to an ultrasonic transducer including a piezoelectric element, a method for manufacturing the ultrasonic transducer, and an ultrasonic endoscope.

  Ultrasonic waves are repeatedly emitted from the ultrasonic transducer to the test site, and echo signals of the ultrasonic waves reflected from the test site are received by the ultrasonic transducer, and a two-dimensional visible image of the test site is obtained. Ultrasonic diagnostic apparatuses capable of displaying a certain ultrasonic image on the screen of a display device are well known and variously proposed.

  In an ultrasonic transducer, electrodes are usually provided on the upper and lower surfaces of a single-plate piezoelectric element, and an acoustic matching layer is provided on the electrode on the upper surface of the piezoelectric element serving as an acoustic radiation surface. It has a configuration in which a lens is provided and an acoustic load material is further provided on the bottom surface of the piezoelectric element. When a voltage is applied from the outside to the electrodes on the upper and lower surfaces of the piezoelectric element, It has a function of radiating sound waves to the test site, receiving reflected sound waves from the test site, and converting them into electrical signals.

  Here, a technique for improving the image quality of an ultrasonic image by widening the frequency band of the ultrasonic wave radiated from the ultrasonic transducer, that is, widening the band is well known.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a configuration in which a plurality of grooves are provided in a piezoelectric element so as to widen the frequency band of ultrasonic waves radiated from an ultrasonic transducer.

  Patent Document 2 discloses that a single-plate piezoelectric element is radiated from an ultrasonic transducer by laminating a composite piezoelectric material in which a plurality of piezoelectric materials are mixed in a predetermined interval with a resin material. A configuration for widening the frequency band of ultrasonic waves is disclosed.

Japanese Utility Model Publication No. 56-147698 JP 2006-320415 A

  However, in the configuration disclosed in Patent Document 1, since a plurality of grooves are formed in the piezoelectric element itself, when an electrode, an acoustic matching layer, and an acoustic load material are provided on the piezoelectric element, a columnar shape formed by the grooves is formed. There is a case where this part is damaged, and it is difficult to handle the piezoelectric element.

  Further, in the configuration disclosed in Patent Document 2, in the electrodes provided on the upper and lower surfaces of the composite piezoelectric material, after applying a voltage to the electrodes due to the difference in linear thermal expansion coefficient between the resin material and the piezoelectric material, In addition to the problem that the part in contact with the boundary between the resin material and the piezoelectric material is easily damaged, the upper surface of the single plate piezoelectric element, the lower surface of the composite piezoelectric element, and the lower surface of the single plate piezoelectric element and the upper surface of the composite piezoelectric body Therefore, there is a problem that the structure is complicated because wiring must be connected to each electrode.

  The present invention has been made in view of the above problems, and an ultrasonic transducer and an ultrasonic transducer capable of realizing a wide frequency band of ultrasonic waves to be radiated in a simple and damage-free configuration. An object of the present invention is to provide an ultrasonic endoscope.

  In order to achieve the above object, an ultrasonic transducer according to an aspect of the present invention includes a piezoelectric element, an upper electrode disposed at least on an upper surface of the piezoelectric element, and a lower electrode disposed at least on a bottom surface of the piezoelectric element; The piezoelectric element disposed at least partially in contact with the lower electrode below the piezoelectric element in a height direction connecting the upper surface and the bottom surface with an acoustic matching layer disposed on the upper surface of the upper electrode. An additional member having a plurality of columnar portions having an acoustic impedance equal to or lower than the acoustic impedance of the acoustic matching layer, and softer than the columnar portions filled between the plurality of columnar portions. And a backing material arranged to cover the additional member from below under the piezoelectric element in the height direction. That.

  An ultrasonic transducer according to another aspect of the present invention includes a polarized first piezoelectric material, an upper electrode disposed on an upper surface of the first piezoelectric material, and a bottom surface of the first piezoelectric material. The same acoustic impedance as the first piezoelectric material, at least part of which is in contact with the lower electrode below the first piezoelectric material in the height direction connecting the lower electrode and the upper surface and the bottom surface And electrically connected to the lower electrode provided on one side surface in the width direction orthogonal to the height direction of the first piezoelectric material and the second piezoelectric material. The first side electrode to which the first wiring is electrically connected, and the side surface on the other side in the width direction of the first piezoelectric material and the second piezoelectric material, The second wiring is electrically connected to the upper electrode. Second side electrodes connected to each other, a plurality of recesses formed on the bottom surface of the second piezoelectric material, a filler filled in the recesses and softer than the columnar part, and the height direction And a backing material arranged so as to cover the first piezoelectric material and the second piezoelectric material from below.

  Furthermore, an ultrasonic transducer manufacturing method according to another aspect of the present invention includes an electrode forming step of forming an upper electrode on at least an upper surface of a piezoelectric element and forming a lower electrode on at least a bottom surface, and an adhesive on the lower electrode. Bonding an additional member having the same acoustic impedance as that of the piezoelectric element through a plurality of recesses on the surface of the additional member opposite to the surface bonded to the lower electrode. A columnar part forming step of forming the columnar part.

  An ultrasonic endoscope according to another aspect of the present invention includes the ultrasonic transducer according to the present invention.

  According to the present invention, an ultrasonic transducer, a method of manufacturing an ultrasonic transducer, and an ultrasonic endoscope capable of realizing a wide frequency band of emitted ultrasonic waves in a simple and damage-free configuration. Can be provided.

Sectional drawing which shows the outline of a structure of the ultrasonic transducer | vibrator of 1st Embodiment The figure which shows the modification of a structure of the additional member of FIG. 1 with a piezoelectric element, a lower electrode, and a filler. The figure which shows the adhesion process of an additional member The figure which shows the state after an additional member was affixed on the lower electrode of FIG. The figure which shows the columnar part formation process which forms a some columnar part in the additional member of FIG. The figure which shows the process of sticking an acoustic matching layer to an upper electrode before the adhesion process of FIG. Sectional drawing which shows schematically the state by which the additional member was affixed on the piezoelectric element in which the lower electrode and upper electrode in the ultrasonic transducer | vibrator of 2nd Embodiment were formed. The partial perspective view which expands and shows a part of columnar part of FIG. 7, and a connection part. Sectional drawing which shows schematically the state by which the additional member was affixed on the piezoelectric element in which the lower electrode and upper electrode in the ultrasonic transducer | vibrator of 3rd Embodiment were formed. Sectional drawing which shows schematically the structure of the ultrasonic transducer | vibrator of 4th Embodiment. Sectional drawing which shows schematically the structure of the ultrasonic transducer | vibrator of 5th Embodiment. FIG. 11 is a partial cross-sectional view schematically illustrating a configuration in which polarization processing is performed only on a region where the upper electrode and the lower electrode face each other with respect to the upper electrode and the lower electrode in FIG. 11. Sectional drawing which shows schematically the state by which the additional member was affixed on the piezoelectric element in which the lower electrode and upper electrode in the ultrasonic transducer | vibrator of 6th Embodiment were formed. A modified example in which a curved concave portion is provided in a region facing the piezoelectric element on the bottom surface of the additional member in FIG. 13 is schematically illustrated in a state where the additional member is attached to the piezoelectric element in which the lower electrode and the upper electrode are formed. Sectional view Sectional drawing which shows schematically the vibrator unit in the ultrasonic vibrator of 7th Embodiment The perspective view which shows schematically the 1st green sheet which comprises the 1st piezoelectric material of FIG. FIG. 16 is a perspective view schematically showing a state in which the upper electrode is formed on the upper surface of the first green sheet of FIG. 16 and the lower electrode is formed on the bottom surface. The perspective view which shows schematically the state which laminated | stacked the 2nd green sheet which comprises a 2nd piezoelectric material on the upper surface of the 1st green sheet of FIG. FIG. 18 is a perspective view schematically showing a state where one side and the other side in the width direction of the piezoelectric element unit in which the second green sheet is laminated on the first green sheet of FIG. 18 are cut. 19 is a perspective view schematically showing a state in which side electrodes are formed on one side and the other side in the width direction of the piezoelectric element unit of FIG. Cross-sectional view schematically showing a state in which an acoustic matching layer unit is attached to a piezoelectric element unit to form a vibrator unit A perspective view showing a transducer unit in an arrayed ultrasonic transducer The perspective view which shows the state which formed the several recessed part in the bottom face of the additional member of FIG. 22 along the depth direction with the dicing saw blade. Sectional drawing which shows the state which filled the recessed part of FIG. 23 with the filler. 24 is a perspective view showing a state in which a plurality of grooves perpendicular to the plurality of recesses are formed in the width direction with respect to the additional member, the piezoelectric element, and the first acoustic matching layer in FIG. The side view which looked at the state which bent the vibrator unit of Drawing 25 from the direction of IIXVI in Drawing 25 24 is a perspective view showing a state in which a plurality of grooves that intersect at an angle other than 90 ° are formed in the plurality of recesses in the width direction with respect to the additional member, the piezoelectric element, and the first acoustic matching layer in FIG. 24. 27 is a top view of the additional member of FIG. 27 as seen from the direction of IIXVIII in FIG. The perspective view which expands and shows one columnar part of FIG. Diagram showing the appearance of an ultrasound endoscope The perspective view which expands and shows the ultrasonic vibration part provided in the front-end | tip part of the insertion part of the ultrasonic endoscope of FIG. Sectional view of the ultrasonic vibration section along the line IIIXII-IIIXII in FIG. Sectional view of the ultrasonic vibration section along the line IIIXIII-IIIXIII in FIG.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is a cross-sectional view schematically illustrating the configuration of the ultrasonic transducer according to the present embodiment. FIG. 2 is a diagram illustrating a modification of the configuration of the additional member in FIG. 1 together with the piezoelectric element, the lower electrode, and a filler. is there.

  As shown in FIG. 1, the ultrasonic transducer 100 oscillates in the height direction Z, which will be described later, thereby radiating ultrasonic waves in the ultrasonic radiation direction ZU in the height direction Z and reflected from the test site. A single-plate piezoelectric element 1 that receives the received sound wave is provided in the housing 10. The piezoelectric element 1 is formed by firing a piezoelectric material such as ceramic. Moreover, the housing 10 is comprised from the insulating member.

  In the housing 10, the upper electrode 2 is provided on the upper surface 1j of the piezoelectric element 1 subjected to the polarization treatment, and the lower electrode 3 is provided on the bottom surface 1t.

  The upper electrode 2 and the lower electrode 3 vibrate the piezoelectric element 1 by applying a pulse voltage transmitted from a controller (not shown) to the piezoelectric element 1 via a first wiring 13 described later. It is. The upper surface 1j constitutes an acoustic radiation surface of the piezoelectric element 1. Further, the upper electrode 2 constitutes a GND electrode, and the lower electrode 3 constitutes a plus electrode.

  In the housing 10, the first acoustic matching layer 4 is provided above the upper electrode 2, specifically, on the upper surface of the upper electrode 2 in the height direction Z connecting the upper surface 1 j and the bottom surface 1 t. In addition, a second acoustic matching layer 5 is provided on the upper surface of the first acoustic matching layer 4.

  Furthermore, an acoustic lens 6 is provided on the upper surface of the second acoustic matching layer 5. In the ultrasonic transducer 100, the first acoustic matching layer 4, the second acoustic matching layer 5, and the acoustic lens 6 are not necessarily required, but in the present embodiment, the first acoustic matching layer 4, The case where the second acoustic matching layer 5 and the acoustic lens 6 are provided is taken as an example.

  Further, in the housing 10, an upper electrode connection portion 12 to which one end of the second wiring 14 is electrically connected is provided on the upper surface of the upper electrode 2 at a portion where the first acoustic matching layer 4 is not provided. It has been. The wirings 13 and 14 are connected to a vibrator driving device (not shown).

  Further, in the housing 10, an additional vibration that vibrates in the height direction Z together with the piezoelectric element 1 along with the vibration of the piezoelectric element 1 below the lower electrode 3 in the height direction Z, specifically, on the bottom surface of the lower electrode 3. The member 7 is bonded so as to contact the lower electrode 3 via an adhesive 16 (see FIG. 3) described later. The additional member 7 is located at the center of the width direction X orthogonal to the height direction Z on the bottom surface of the lower electrode 3.

  The additional member 7 is made of a piezoelectric material having the same acoustic impedance as the piezoelectric material constituting the piezoelectric element 1 or a material having an acoustic impedance equal to or higher than that of the acoustic matching layer 4 in contact with the piezoelectric element, which is equal to or lower than the acoustic impedance of the piezoelectric element 1. It is comprised by either.

  For example, the additional member 7 is made of ceramic or the like that is the same material as the piezoelectric material constituting the piezoelectric element 1. In addition, if the piezoelectric element 1 and the additional member 7 are made of the same material, the reflection of sound waves caused by the difference in acoustic impedance does not occur at the interface between the piezoelectric element 1 and the additional member 7. The sensitivity of the child 100 can be improved.

Further, the additional member 7 is fixed to the lower surface of the lower electrode 3 in a non-piezoelectric state because it is not polarized. This is because the additional member 7 is not polarized, and the piezoelectric material constituting the additional member 7 is the same as the piezoelectric material constituting the piezoelectric element 1. Since unnecessary potential does not accumulate on the bottom surface 7t of the member 7 and the bottom surface 7hm of the concave portion 7h described later, the additional member 7 is involved only in vibration as a structure, so that the vibration of the piezoelectric element 1 is not hindered. Because. Further, if the polarization treatment is not performed, no internal stress is generated in the additional member 7, so that the shape and structure are stabilized, and the cost can be reduced.
The additional member need not be the same material as that of the piezoelectric element, and may be any material as long as vibration is easily transmitted from the piezoelectric element. Examples thereof include ceramics, metals, and resin materials. More specifically, examples include alumina, zirconia, duralumin, aluminum, glass, MgO—Al ₂ O ₃ —SiO ₂ ceramics, and materials in which powders such as metals are mixed with epoxy resin.

  The additional member 7 is elongated in the height direction Z and provided with a set interval in the width direction X, and on the lower electrode 3 side in the height direction Z of each columnar portion 7c. The main portion is configured by including a plurality of connecting portions 7r that connect the end portions 7ct along the width direction X, so that the cross-sectional shape in the height direction Z has a comb shape. That is, a recess 7 h is formed between each columnar portion 7 c in the width direction X.

  In addition, as shown in FIG. 2, the additional member 7 may be comprised only from the some columnar part 7c. In this case, the end portion 7ct of each columnar portion 7c is fixed to the lower electrode 3 by, for example, a known p-MUT.

  The recess 7h is filled with a filler 8 that is softer than the columnar portion 7c and improves the vibration efficiency of the additional member 7. In addition, as the filler 8, a soft epoxy resin, a silicone resin, etc. are mentioned. In addition, the recess 7 h may be filled with a backing material 9 described later instead of the filler 8.

  The additional member 7 has a plurality of columnar portions 7c and a plurality of concave portions 7h, so that the thickness in the height direction Z differs in the width direction X. That is, the thickness in the height direction Z differs between the plurality of columnar portions 7c and the plurality of connecting portions 7r.

  From this, when the plurality of columnar portions 7c and the plurality of connecting portions 7r vibrate in the height direction Z along with the vibration of the piezoelectric element 1, the portion where the plurality of columnar portions 7c of the additional member 7 is provided is By virtue of the total thickness of the thickness Z10 in the height direction Z of the piezoelectric element 1 and the thickness Z12 in the height direction Z of the plurality of columnar portions 7c, vibration having a lower frequency than that of the coupling portion 7r is excited.

  Further, the portion of the additional member 7 provided with the plurality of connecting portions 7r includes a thickness Z10 in the height direction Z of the piezoelectric element 1 and a thickness Z11 in the height direction Z of the plurality of connecting portions 7r smaller than the thickness Z12. The total thickness excites vibrations at a higher frequency than the columnar portion 7c.

  That is, the additional member 7 can broaden the frequency band of the ultrasonic wave radiated from the piezoelectric element 1.

  In the present embodiment, the additional member 7 is formed such that the width X1 in the width direction X orthogonal to the height direction Z is smaller than the width X2 in the width direction X of the piezoelectric element 1 (X1). <X2).

  This is because if the width X1 of the additional member 7 is smaller than the width X2 of the piezoelectric element 1, the region where the additional member 7 is provided in the ultrasonic transducer 100 is the center in the width direction X of the piezoelectric element 1. Since both sides of the additional member 7 in the width direction X are regions where the additional member 7 is not provided, the sensitivity of the central region is improved by the additional member 7, and the additional member 7 is provided. Since the sensitivity is relatively lowered in the regions at both ends, a known side lobe in which ultrasonic waves leak in a direction different from the ultrasonic radiation direction ZU is less likely to occur from the regions at both ends, and the sound field is improved. It is.

  Further, on the bottom surface of the lower electrode 3, a lower electrode connection portion 11 to which one end of the first wiring 13 is electrically connected is provided in a region where the additional member 7 is not in contact. The other end of the first wiring 13 is connected to, for example, a signal cable 90 (see FIG. 30) extended from the ultrasonic observation apparatus.

  The lower electrode connection unit 11 transmits a pulse voltage transmitted through the signal cable 90 and the first wiring 13 to the lower electrode 3 and also receives a reception signal from the piezoelectric element 1 through the first wiring 13. The signal is transmitted to the signal cable 90.

  Further, in the housing 10, a backing material 9 that attenuates unnecessary ultrasonic waves is provided below the lower electrode 3 in the height direction Z so as to cover the additional member 7 and the lower electrode connecting portion 11.

  The backing material 9 also functions as a member that fixes the vibrator unit 150 in which the additional member 7 and the acoustic matching layers 4 and 5 are fixed to the piezoelectric element 1 with respect to the housing 10.

  Next, a method for manufacturing the ultrasonic transducer 100 will be described with reference to FIGS. FIG. 3 is a view showing the bonding process of the additional member, FIG. 4 is a view showing a state after the additional member is attached to the lower electrode of FIG. 3, and FIG. 5 is a plurality of columnar shapes on the additional member of FIG. The figure which shows the columnar part formation process which forms a part, FIG. 6 is a figure which shows the process of sticking an acoustic matching layer to an upper electrode before the adhesion | attachment process of FIG.

  When manufacturing the ultrasonic transducer 100, first, after the piezoelectric material of the piezoelectric element 1 is baked, an electrode forming process is performed in which the upper electrode 2 is formed on the upper surface 1j and the lower electrode 3 is formed on the bottom surface 1t.

  Next, as shown in FIGS. 3 and 4, the adhesive 16 is applied to the lower electrode 3 or the additional member 7, and the additional member 7 is raised with respect to the position of the lower electrode 3 through the adhesive 16. An adhesion process is performed in which pressure is applied from above and below in the direction Z. In addition, as the adhesive agent 16, an epoxy adhesive agent etc. are mentioned.

  In addition, in the bonding step, the additional member 7 and the piezoelectric element 1 are moved slightly in the in-plane direction of the lower electrode 3 as necessary, so that the adhesive layer made of the adhesive 16 is made a thin layer of, for example, 30 μm or less.

  The reason why the adhesive layer is formed in a thin layer is that when the adhesive layer is thick, the above-described acoustic wave reflection is likely to occur in the adhesive layer, and sound attenuation particularly in the high frequency region is likely to occur in the adhesive layer. This is because the characteristics of the vibrator are deteriorated.

  Further, in order to make the adhesive layer thin, it is necessary to pressurize the piezoelectric element 1 and the additional member 7 strongly. In addition, after bonding, heating is performed while maintaining the pressurized state to fix the bonded state.

  Next, as shown in FIG. 5, for example, a dicing saw blade 17 is used on the surface 7 t on the opposite side to the surface bonded to the lower electrode 3 of the additional member 7 in the height direction Z to set the interval in the width direction X. A plurality of recesses 7h having a predetermined depth in the height direction Z are formed so as to have a columnar portion forming step of forming the plurality of columnar portions 7c described above.

  In addition, the columnar part forming step was performed after the additional member 7 was adhered to the lower electrode 3. If the columnar part forming step was performed on the additional member 7 before the adhesion, the bonding was performed as described above. This is because when a plurality of recesses 7h are already formed in the additional member 7 when the layer is pressed strongly to make the layer thin, there is a high possibility that the plurality of columnar portions 7c will be damaged by the pressing. .

  Therefore, by performing the columnar part forming step after the bonding step, the thickness of the adhesive layer can be sufficiently reduced, and damage to the additional member 7 can be prevented.

  In the columnar portion forming step, as shown in FIG. 5, the surface in contact with the filler 8 of the connecting portion 7 r located at the center in the width direction X, that is, the bottom surface 7 hm of the recess 7 h is one end side in the width direction X and The surface of the connecting portion 7r located on the other end side that is in contact with the filler 8, ie, the bottom surface 7hm of the concave portion 7h is recessed toward the piezoelectric element 1 (Z1 <Z2 <Z3).

  In other words, the recess 7h located at the center in the width direction X is formed deeper in the height direction Z than the recess 7h located at one end and the other end in the width direction X.

  This is because, as described above, the thinner one in the height direction of the connecting portion 7r can excite strong high-frequency vibration, and the thicker one can excite strong low-frequency vibration. By forming the concave portion 7h located at one end side and the other end side shallower in the height direction Z than the concave portion 7h located at the center in the width direction X, the above-described side is formed from the regions at both ends of the ultrasonic transducer 100. This is because lobes are less likely to occur and the sound field is improved.

  Although not shown, when the depth of the recess 7h is randomly formed in the width direction X, the frequency band of the ultrasonic transducer 100 is improved.

  After the columnar portion forming step, the upper electrode 2 is provided with the acoustic matching layer unit 130 composed of the second acoustic matching layer 5 and the first acoustic matching layer 4, and the first acoustic matching layer 4 is the upper electrode 2. The acoustic lens 6 is provided on the second acoustic matching layer 5, the first wiring 13 is electrically connected to the lower electrode connection portion 11, and the second electrode is connected to the upper electrode connection portion 12. The vibrator unit 150 is manufactured by electrically connecting the wirings 14, and finally, the ultrasonic unit 100 is manufactured by bonding and fixing the vibrator unit 150 in the housing 10 via the backing material 9. To do.

  As shown in FIG. 6, the first acoustic matching layer 4 is preferably bonded to the upper electrode 2 via the adhesive 19 before the bonding step of bonding the additional member 7 to the lower electrode 3.

  This is because when the additional member 7 is attached to the lower electrode 3 and a plurality of recesses 7 h are formed in the additional member 7 and then the acoustic matching layer unit 130 is attached to the upper electrode 2, the acoustic matching layer unit for the upper electrode 2 This is because the adhesion of 130 is also performed by pressurization, so that the plurality of columnar portions 7c formed by the recesses 7h are likely to be damaged during pressurization, as described above.

  That is, if the acoustic matching layer unit 130 is bonded to the upper electrode 2 before the additional member 7 is bonded to the lower electrode 3, the acoustic matching is performed before the plurality of recesses 7h are formed in the additional member 7. Since the layer unit 130 can be sufficiently pressed and bonded to the upper electrode 2, the adhesive layer made of the adhesive 19 can be made sufficiently thin as described above, thereby preventing the above-described reflection of sound waves. This is because the sensitivity of the ultrasonic transducer 100 can be improved.

  As described above, in the present embodiment, the lower electrode 3 formed on the bottom surface 1t of the piezoelectric element 1 has the same acoustic impedance as the piezoelectric element 1 and has non-piezoelectricity. It is shown that an additional member 7 that vibrates is provided.

  In addition, when the plurality of columnar portions 7 c and the plurality of connecting portions 7 r vibrate in the height direction Z with the vibration of the piezoelectric element 1, the additional member 7 has the height of the piezoelectric element 1. The total thickness of the thickness Z10 in the direction Z and the thickness Z12 in the height direction Z of the plurality of columnar portions 7c excites strong vibration at a lower frequency than the connecting portion 7r, and the plurality of connecting portions 7r The total thickness of the thickness Z10 in the height direction Z and the thickness Z11 in the height direction Z of a plurality of connecting portions smaller than the thickness Z12 has been shown to excite vibrations having a higher frequency than the columnar portion 7c.

  According to this, by simply laminating the additional member 7 on the piezoelectric element 1 without laminating the composite piezoelectric body on the piezoelectric element or forming a plurality of recesses in the piezoelectric element itself, Since the frequency band of the ultrasonic wave radiated from the piezoelectric element 1 can be widened, it is possible to realize the widening of the frequency band of the radiated ultrasonic wave in a simple configuration that prevents the piezoelectric element 1 from being damaged. The ultrasonic transducer 100 and a method for manufacturing the ultrasonic transducer 100 can be provided.

(Second Embodiment)
FIG. 7 is a cross-sectional view schematically showing a state where an additional member is attached to the piezoelectric element in which the lower electrode and the upper electrode are formed in the ultrasonic transducer of this embodiment, and FIG. 8 is a columnar shape of FIG. It is a fragmentary perspective view which expands and shows a part of a part and a connection part.

  The configuration of the ultrasonic transducer according to the second embodiment includes a plurality of concave portions formed in the additional member as compared with the ultrasonic transducer according to the first embodiment shown in FIGS. The difference is that the bottom surface is formed on a curved surface. Therefore, only this difference will be described, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted.

  As shown in FIGS. 7 and 8, in the additional member 7, the bottom surface 7hm of the plurality of recesses 7h that are in contact with the filler 8 of the connecting portion 7r has a curvature in the width direction X between the columnar portions 7c. And formed into a shape to be connected.

  As shown in FIG. 7, the bottom surface 7hm is formed into a shape having a curvature by forming a plurality of recesses 7h in the additional member 7 by a dicing saw blade 17 having an R surface 17r at the tip. Other configurations are the same as those in the first embodiment described above.

  According to such a configuration, as shown in FIG. 8, the plurality of columnar portions 7c become wider in the width direction X toward the lower electrode 3 side in the height direction Z (X4 < X5 <X6), the mechanical strength of the portion of the plurality of columnar portions 7c adjacent to the lower electrode 3 is improved, and the portion is less likely to be damaged than the first embodiment described above, and as shown in FIG. In addition, the vibration in the direction M that falls in the width direction X and the depth direction Y orthogonal to the height direction Z and the width direction X is less likely to occur in each columnar portion 7c, and the vibration is likely to occur in the height direction Z. For this reason, the vibrator sensitivity in the ultrasonic vibrator 100 is improved. Other effects are the same as those of the first embodiment described above.

(Third embodiment)
FIG. 9 is a cross-sectional view schematically showing a state in which the additional member is attached to the piezoelectric element in which the lower electrode and the upper electrode are formed in the ultrasonic transducer of the present embodiment.

  The configuration of the ultrasonic transducer according to the third embodiment is the same as that of the ultrasonic transducer according to the first embodiment shown in FIGS. 1 to 6 and the second embodiment shown in FIGS. In the additional member 7, the columnar portion 7 c located at the center in the width direction X is narrower than the width of the columnar portion 7 c located on one side and the other side in the width direction X in the additional member 7. Is different. Therefore, only this difference will be described, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted.

  As shown in FIG. 9, in the plurality of columnar portions 7c of the additional member 7, the width of the columnar portion 7c located at the center in the width direction X is the width of the columnar portion 7c located on one side and the other side in the width direction X. (X10 <X11 <X12).

  In other words, the width of the recess 7h located at the center in the width direction X is smaller than the width of the recess 7h located on one side and the other side in the width direction X (X15 <X16 <X17). Other configurations are the same as those of the first and second embodiments described above.

  According to such a configuration, the side lobe described above is reduced, so that the performance of the ultrasonic transducer 100 can be improved. The other effects are the same as those of the first and second embodiments described above.

(Fourth embodiment)
FIG. 10 is a cross-sectional view schematically showing the configuration of the ultrasonic transducer of the present embodiment.

  The configuration of the ultrasonic transducer of the fourth embodiment is the same as that of the first embodiment shown in FIGS. 1 and 2, the ultrasonic transducer of the second embodiment shown in FIGS. Compared with the ultrasonic transducer of the third embodiment shown in FIG. 9, the second wiring 14 is electrically connected to the upper electrode 2 at the bottom surface 1 t of the piezoelectric element 1. Different. Therefore, only this difference will be described, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted.

  In the first embodiment described above, it is shown that the second wiring 14 is electrically connected to the upper electrode 2 via the upper electrode connecting portion 12 provided on the upper surface of the upper electrode 2. It was.

  However, this configuration has a problem that it is difficult to structurally connect the one end side of the second wiring 14 to the upper electrode connection portion 12.

  Therefore, in the present embodiment, as shown in FIG. 10, on the bottom surface 1t of the piezoelectric element 1, one of the width direction different from the region where the lower electrode 3 is provided and the region where the additional member 7 is provided. The upper electrode 2 is pulled out from the upper surface 1j of the piezoelectric element 1 through the side surface 1s on one side in the width direction X in the region on the side, and the upper electrode leading portion 30 is provided in the portion pulled out to the bottom surface 1t. The second wiring 14 is electrically connected to the part 30. Other configurations are the same as those of the first and second embodiments described above.

  According to such a configuration, since the connection portion of the second wiring 14 with respect to the upper electrode 2 is eliminated on the upper surface 1j side, the first acoustic matching layer is formed on the entire upper surface of the upper electrode 2 as shown in FIG. 4 can be bonded, so that the performance of the ultrasonic transducer 100 can be improved. In addition, as in the first embodiment, the upper electrode lead-out portion 30 and the lower electrode connection portion 11 are connected by the additional member 7. Since it can be provided on one side and the other side in the width direction X relative to the provided region, the sensitivity of the ultrasonic transducer is less likely to be lowered due to the arrangement of the wiring.

  Other effects are the same as those of the first and second embodiments described above.

(Fifth embodiment)
FIG. 11 is a cross-sectional view schematically showing the configuration of the ultrasonic transducer according to the present embodiment. FIG. 12 shows only the region where the upper electrode and the lower electrode face the upper electrode and the lower electrode in FIG. It is a fragmentary sectional view which shows roughly the structure which performs a polarization process to.

  The configuration of the ultrasonic transducer of this fifth embodiment is such that the upper electrode 2 and the lower electrode 3 are compared with the upper electrode 2 in comparison with the ultrasonic transducer of the fourth embodiment shown in FIG. The difference is that only the region where 2 and the lower electrode 3 face each other is polarized. Therefore, only this difference will be described, the same reference numerals are given to the same components as those in the fourth embodiment, and the description thereof will be omitted.

  As shown in FIG. 11, the upper electrode 2 and the lower electrode 3 are opposed to the upper electrode 2 and the lower electrode 3 in a configuration in which the upper electrode 2 is drawn from the upper surface 1j to the bottom surface 1t through the side surface 1s. 12 is used only in the region H that overlaps the additional member 7 of the upper electrode 2 and the lower electrode 3 in a state viewed in plan from the acoustic lens 6 side in the height direction Z, as shown in FIG. Polarization processing may be performed so that only the region H of the upper electrode 2 and the lower electrode 3 is polarized. Other configurations are the same as those in the fourth embodiment described above.

  According to such a configuration, the piezoelectric element 1 vibrates in the height direction Z only in the region where the additional member 7 is adhered. Since the vibration is suppressed, the generation of the side lobe described above can be suppressed. Other effects are the same as those of the fourth embodiment described above.

(Sixth embodiment)
FIG. 13 is a cross-sectional view schematically showing a state in which the additional member is attached to the piezoelectric element in which the lower electrode and the upper electrode are formed in the ultrasonic transducer of the present embodiment.

  The configuration of the ultrasonic transducer of the sixth embodiment is the same as that of the ultrasonic transducer of the first embodiment shown in FIGS. 1 to 6 and the second embodiment shown in FIGS. Ultrasonic vibrator, the ultrasonic vibrator of the third embodiment shown in FIG. 9, the ultrasonic vibrator of the fourth embodiment shown in FIG. 10, the fifth embodiment shown in FIGS. The additional member 7 is formed wider than the piezoelectric element 1 in the width direction X and the surface of the additional member 7 in contact with the backing material 9 is compared with the lower electrode 3 in comparison with the ultrasonic transducer of FIG. The first wiring 13 is electrically connected, and the second wiring 14 is electrically connected to the upper electrode 2.

  Therefore, only this difference is demonstrated, the same code | symbol is attached | subjected to the structure similar to 1st-5th embodiment, and the description is abbreviate | omitted.

  As shown in FIG. 13, the upper electrode 2 formed on the upper surface 1 j of the piezoelectric element 1 is formed by being drawn out to the side surface 1 sa on one side in the width direction X. The upper electrode 2 is not electrically connected to the lower electrode 3 because it is not formed on the other side in the width direction X on the upper surface 1j.

  Further, the lower electrode 3 formed on the bottom surface 1t of the piezoelectric element 1 is formed to be drawn to the other side surface 1sb in the width direction X. The lower electrode 3 is not electrically connected to the upper electrode 2 because it is not formed on one side in the width direction X on the bottom surface 1t.

  Moreover, in this Embodiment, the additional member 7 is extended and located in the one side and the other side of the width direction X rather than the some columnar part 7c other than the some columnar part 7c and the some connection part 7r. The extending portions 7e1 and 7e2 are provided. Therefore, the width X7 of the additional member 7 in the width direction X is formed to be larger than the width X2 of the piezoelectric element 1 in the width direction X by the extending portions 7e1 and 7e2 (X2 <X7).

  Further, an electrode 42 is formed on the upper surface 7j, the side surface 7sa, and the bottom surface 7t that is a surface in contact with the backing material 9 in the one-side extended portion 7e1, and the upper surface 7j, the side surface 7sb in the other-side extended portion 7e2, An electrode 43 is also formed on the bottom surface 7t.

  The electrode 43 is also formed on the upper surface 7j of the region where the plurality of columnar portions 7c and the plurality of connecting portions 7r are formed in the width direction X.

  Further, the upper electrode 2 and the electrode 42 are electrically connected by using the conductive adhesive 35 between the upper surface 7j of the extending portion 7e1 and the side surface 1sa of the piezoelectric element 1, and the lower electrode 3 and the electrode 43 are electrically connected by using a conductive adhesive 36 between the upper surface 7j of the extending portion 7e2 and the side surface 1sb of the piezoelectric element 1.

  As a result, the bottom surface 7t of the extended portion 7e2 is provided with the lower electrode lead portion 44 from which the lower electrode 3 is drawn and to which the first wiring 13 is electrically connected, and the extended portion 7e1. The bottom electrode 7t is provided with an upper electrode lead portion 45 from which the upper electrode 2 is drawn and to which the second wiring 14 is electrically connected.

  When forming the ultrasonic transducer configured as described above, first, the electrodes 42 and 43 are disposed on the lower electrode 3 side of the piezoelectric element 1 in which the upper electrode 2 and the lower electrode 3 are formed at the positions described above. The additional member 7 formed at the position is bonded and fixed.

  Next, the electrode 42 of the additional member 7 is electrically connected to the upper electrode 2 via the conductive adhesive 35, and the electrode 43 of the additional member 7 is connected to the lower electrode 3 via the conductive adhesive 36. Connect electrically.

  Thereafter, after the acoustic matching layer unit 130 is bonded to the upper electrode 2 side of the piezoelectric element 1, a plurality of recesses 7h are formed on the bottom surface 7t of the additional member 7 in the same manner as in the first embodiment.

  Thereafter, the first wiring 13 is electrically connected to the lower electrode leading portion 44 using solder or the like, and the second wiring 14 is electrically connected to the upper electrode leading portion 45 using solder or the like. Connecting.

  Next, the housing 10 (see FIG. 1) is filled with the backing material 9, and then the vibrator unit 150 is stuck in the housing 10 so that the bottom surface 7 t of the additional member 7 is in contact with the backing material 9.

  Finally, the acoustic lens 6 is formed on the second acoustic matching layer 5, and the ultrasonic transducer 100 is formed.

  The acoustic lens 6 may be formed before the first wiring 13 and the second wiring 14 are connected. In addition, if the filling material 8 is filled in the recesses 7h of the additional member 7 before placing the vibrator unit 150 on the backing material 9 in the housing 10, the filling condition of the filling material 8 in the recesses 7h is increased. Since it can be confirmed, the reliability of the ultrasonic transducer 100 is further improved.

  According to such a configuration and manufacturing method, since the first wiring 13 and the second wiring 14 are connected to the bottom surface 7t of the additional member 7, the solder is applied to the piezoelectric element 1 during the connection. Since no thermal load is applied at the time of attachment, the deterioration of the piezoelectric element 1 due to soldering and deterioration due to thermal stress can be eliminated, so that the reliability of the ultrasonic transducer 100 is further improved. Other effects are the same as those of the first to fifth embodiments described above.

  Hereinafter, a modification will be described with reference to FIG. FIG. 14 shows a modified example in which a curved concave portion is provided in a region facing the piezoelectric element on the bottom surface of the additional member in FIG. 13, and the additional member is attached to the piezoelectric element in which the lower electrode and the upper electrode are formed. It is sectional drawing shown roughly in the state.

  In the first to sixth embodiments described above, the plurality of columnar portions 7c are formed in the width direction by forming the plurality of concave portions 7h at the set intervals along the width direction X on the bottom surface 7t of the additional member 7. In X, it is shown that it is formed with a set interval.

  Not limited to this, as shown in FIG. 14, for example, in the region facing the piezoelectric element 1 on the bottom surface 7 t of the additional member 7, the thickness in the height direction Z is thinner in the center region in the width direction X, and the width from the center region is reduced. A curved concave portion 7p in which the thickness in the height direction Z increases as it goes to one side and the other side in the direction X may be formed.

  The thickness is not limited to the curved concave portion 7p, and the thickness in the height direction Z is thinner toward the center region in the width direction X, and the thickness in the height direction Z is increased from the center region toward one side and the other side in the width direction X. As long as the shape increases, a step or a known plano concave shape may be used. Other configurations are the same as those in the first to sixth embodiments described above.

  According to such a configuration, when the additional member 7 vibrates with the vibration of the piezoelectric element 1, the thickness in the height direction Z of the central region is thin as in the first to sixth embodiments described above. From the central region of the additional member 7, strong vibrations with high frequency can be excited, and since the extending portions 7 e 1 and 7 e 2 have a large thickness in the height direction Z, strong vibrations with low frequency can be excited. It is possible to easily generate vibration having a distribution using a single piezoelectric element plate. The other effects are the same as those of the first to sixth embodiments described above.

(Seventh embodiment)
FIG. 15 is a cross-sectional view schematically showing a transducer unit in the ultrasonic transducer of the present embodiment.

  The configuration of the ultrasonic transducer of the seventh embodiment is the same as that of the ultrasonic transducer of the first embodiment shown in FIGS. 1 to 6 and the second embodiment shown in FIGS. Ultrasonic vibrator, the ultrasonic vibrator of the third embodiment shown in FIG. 9, the ultrasonic vibrator of the fourth embodiment shown in FIG. 10, the fifth embodiment shown in FIGS. Compared with the ultrasonic vibrator of FIG. 13 and the ultrasonic vibrator of the sixth embodiment shown in FIG. 13, the difference is that the piezoelectric element and the additional member are integrally formed as a piezoelectric element unit.

  Therefore, only this difference is demonstrated, the same code | symbol is attached | subjected to the structure similar to 1st-6th embodiment, and the description is abbreviate | omitted.

  As shown in FIG. 15, in the present embodiment, the piezoelectric element 1 and the additional member 7 are integrally formed as a piezoelectric element unit 25.

  Specifically, the piezoelectric element unit 25 includes a first piezoelectric material 21 that has been subjected to polarization processing, and an upper portion provided in a region excluding one side in the width direction X on the upper surface 21j of the first piezoelectric material 21. On the bottom surface 21 t of the electrode 22 and the first piezoelectric material 21, the lower electrode 23 provided in a region excluding the other side in the width direction X, and the bottom surface 21 t below the height direction Z of the first piezoelectric material 21. The second piezoelectric material 24 having the same acoustic impedance as that of the first piezoelectric material that is in contact with the lower electrode 23 formed on one side surface in the width direction X of the piezoelectric element unit 25 is electrically connected. The first side electrode 26 and a second side electrode 27 formed on the other side surface in the width direction X of the piezoelectric element unit 25 and electrically connected to the upper electrode 22 are provided, and the main part is provided. It is configured. The first wiring 13 is electrically connected to the first side electrode 26, and the second wiring 14 is electrically connected to the second side electrode 27.

  In addition, the acoustic matching layer unit 130 is attached to the surface 25j on the upper electrode 22 side of the piezoelectric element unit 25, specifically, the upper surface 21j of the first piezoelectric material 21, thereby constituting the vibrator unit 150 ′. A surface 25t opposite to the surface 25j of the piezoelectric element unit 25 in the height direction Z, specifically, a bottom surface 24t of the second piezoelectric material 24 has a set interval in the width direction X. By forming the plurality of concave portions 25h, a plurality of columnar portions 25c and a plurality of connecting portions 25r are formed.

  Although not shown, the plurality of recesses 25h are filled with the filler 8 described above. Although not shown, the backing material 9 is located below the surface 25t as in the first to sixth embodiments described above. Other configurations are the same as those in the first to sixth embodiments described above.

  Next, a method for manufacturing the ultrasonic transducer of the present embodiment will be described with reference to FIG. 15 and FIGS.

  16 is a perspective view schematically showing a first green sheet constituting the first piezoelectric material of FIG. 15, and FIG. 17 is a bottom view of an upper electrode formed on the upper surface of the first green sheet of FIG. FIG. 18 is a perspective view schematically showing a state in which a lower electrode is formed on FIG. 18, and FIG. 18 schematically shows a state in which a second green sheet constituting the second piezoelectric material is laminated on the upper surface of the first green sheet in FIG. It is a perspective view shown in FIG.

  19 is a perspective view schematically showing a state in which one side and the other side in the width direction of the piezoelectric element unit in which the second green sheet is stacked on the first green sheet of FIG. 18 are cut. FIG. 21 is a perspective view schematically showing a state where side electrodes are formed on one side and the other side in the width direction of the piezoelectric element unit in FIG. 19, and FIG. 21 is a diagram in which an acoustic matching layer unit is attached to the piezoelectric element unit; It is sectional drawing which shows schematically the state in which the vibrator unit was formed.

  First, as shown in FIG. 16, the 1st green sheet 21 which comprises the 1st piezoelectric material is produced. After that, as shown in FIG. 17, the upper electrode 22 is formed along the depth direction Y on the upper surface 21 j in the height direction Z of the first green sheet 21 except for one region in the width direction X. The lower electrode 23 is formed on the bottom surface 21t along the depth direction Y except for the region on the other side in the width direction X.

  Next, as shown in FIG. 18, the second green sheet 24 constituting the second piezoelectric material is formed on the bottom surface 21 t on the lower electrode 23 side of the first green sheet 21 to form the piezoelectric element unit 25. To do.

  Thereafter, after firing the piezoelectric element unit 25, as shown in FIG. 19, one side and the other side in the width direction X of the piezoelectric element unit 25 are cut along a dotted line D along the depth direction in FIG. The width of the element unit 25 in the width direction X is adjusted. As a result, as shown in FIG. 19, the lower electrode 23 is exposed along the depth direction Y on one side surface of the piezoelectric element unit 25.

  Next, as shown in FIG. 20, a first side electrode 26 is formed on one side surface of the piezoelectric element unit 25 by sputtering, baking, or the like. As a result, the lower electrode 23 exposed on the one side surface and the first side electrode 26 are electrically connected.

  Further, as shown in FIG. 20, a second side electrode 27 is formed on the other side surface of the piezoelectric element unit 25 by sputtering, baking, or the like. As a result, the first side electrode 27 is electrically connected to the upper electrode 22 on the upper surface 21j of the first green sheet 21.

  Then, as shown in FIG. 21, the acoustic matching layer unit 130 is attached to the surface of the piezoelectric element unit 25 on the upper electrode 22 side, and then, as shown in FIG. 15, on the surface 25t of the piezoelectric element unit 25, By forming a plurality of recesses 25h having set intervals along the width direction X, a plurality of columnar portions 25c and a connecting portion 25r are formed.

  Finally, the first wiring 13 is electrically connected to the first side electrode 26 by solder or the like, and the second wiring 14 is electrically connected to the second side electrode 27 by solder or the like to vibrate. A child unit 150 ′ is formed. The subsequent steps are the same as those in the first embodiment described above.

  According to such a configuration, since there is no adhesive layer between the first piezoelectric material 21 and the second piezoelectric material 24, the above-described reflection of the sound wave by the adhesive layer can be eliminated. The sensitivity of the child 100 can be improved. The other effects are the same as those of the first to sixth embodiments described above.

(Eighth embodiment)
FIG. 22 is a perspective view showing a transducer unit in an arrayed ultrasonic transducer, and FIG. 23 shows a state in which a plurality of concave portions are formed by a dicing saw blade along the depth direction on the bottom surface of the additional member in FIG. It is a perspective view shown.

  24 is a cross-sectional view showing a state in which the concave portion of FIG. 23 is filled with a filler, and FIG. 25 is orthogonal to a plurality of concave portions with respect to the additional member, the piezoelectric element, and the first acoustic matching layer of FIG. 26 is a perspective view showing a state in which a plurality of grooves are formed in the width direction, and FIG. 26 is a side view of the state in which the vibrator unit of FIG. 25 is bent as viewed from the direction of IIXVI in FIG.

  The configuration of the ultrasonic transducer according to the eighth embodiment is different from the ultrasonic transducer according to the fourth embodiment shown in FIG. 10 in that the ultrasonic transducer is formed in an array. . That is, since the configuration of the ultrasonic transducer of the fourth embodiment is the same as that of the fourth embodiment except that the ultrasonic transducer is in an array, description thereof is omitted.

  As shown in FIG. 25, the piezoelectric element 51, the first acoustic matching layer 54, the second acoustic matching layer 55, and the additional member 57 of the transducer unit 250 in the ultrasonic transducer 200 of the present embodiment are the fourth The piezoelectric element 1, the first acoustic matching layer 4, the second acoustic matching layer 5, and the additional member 7 of the embodiment are composed of large plates that are formed larger in the width direction X and the depth direction Y, respectively. The plurality of columnar portions 57c, the piezoelectric elements 51, and the first acoustic matching layer 54 are formed in an array in the width direction X and the depth direction Y.

  In addition, since the magnitude | size and arrangement | positioning relationship between each other member are the same as the ultrasonic transducer | vibrator 100 of 4th Embodiment mentioned above, the description is abbreviate | omitted.

Next, a method for manufacturing the ultrasonic transducer 200 of the present embodiment will be described.
First, as shown in FIG. 22, the acoustic matching layer unit 230 is attached to the upper surface 51j of the piezoelectric element 51 on which the upper electrode 52 and the lower electrode 53 are formed at the same position as the ultrasonic transducer 100 of FIG. At the same time, the additional member 57 is attached to the center of the bottom surface 51 t of the piezoelectric element 51 in the width direction X to form the vibrator unit 250.

  Next, as shown in FIG. 23, using the dicing saw blade 60, the depth direction Y has a set interval in the width direction X with respect to the bottom surface 57t of the additional member 57 and is parallel to the width direction X. A plurality of recesses 57h penetrating from one end 57y1 to the other end 57y2 is formed. In FIG. 23, the bottom surface 57hm of the recess 57h is formed in a shape having a curvature, but is not limited to this shape.

  Thereafter, as shown in FIG. 24, a filling material filling step is performed in which each concave portion 57 h is filled with a filling material 58 that is softer than the additional member 57 and has the same configuration as the filling material 8 described above. Each recess 57h may be filled with the backing material 9 as in the first to seventh embodiments. Further, the reason why the filling material 58 and the backing material 9 are filled in the recess 57h is to prevent cracking of each columnar portion 57c when divided into element units to be described later as shown in FIG.

  Next, as shown in FIG. 25, the additional member 57, the piezoelectric element 51, and the first acoustic matching layer 54 have a set interval in the depth direction Y so as to penetrate in the height direction Z, and in the depth direction. A groove forming step of forming a plurality of parallel grooves 63 from one side to the other side along the width direction X is performed again using the dicing saw blade 60 so as to be orthogonal to the plurality of recesses 57h. The groove 63 is not formed in the second acoustic matching layer 55. As a result, in the additional member 7, in the width direction X and the depth direction Y, a plurality of columnar portions 57c, the piezoelectric elements 51, and the first acoustic matching layers 54 are formed in an array.

  Thereafter, as shown in FIG. 26, the vibrator unit 250 is pressed in the depth direction Y and the center in the width direction X downward in the height direction Z, starting from the plurality of grooves 63, along the depth direction Y. Then, a bending process is performed in which the arc is bent at a predetermined angle. In addition, it becomes a convex type ultrasonic vibrator by being bent at a predetermined angle.

  The bending step may be a step of bending the vibrator unit 250 in the depth direction Y so that the one end 57y1 and the other end 57y2 come into contact with each other, starting from the plurality of grooves 63. In addition, a radial type ultrasonic vibrator is obtained by being bent in a circumferential shape.

  Thereafter, as shown in FIG. 10, each lower electrode connecting portion 11 (see FIG. 10) electrically connected to the lower electrode 53 in a row unit (element) along the width direction X of the plurality of columnar portions 57 c. In addition, the first wiring is electrically connected to each other.

  Specifically, in FIG. 25, since 10 elements of a plurality of columnar portions 57c are formed, 10 first wires are connected to 10 lower electrode connection portions 11 for each element. Each is connected individually.

  Further, with respect to the upper electrode 52 serving as the GND electrode, the upper electrode lead portion 30 (see FIG. 10) provided in each element does not need to connect the second wiring 14 to the upper electrode 52 in element units. All elements may be electrically connected to the upper electrode 52 by collective wiring.

  As a specific method, a method in which a common terminal is electrically connected to the upper electrode 52 of the piezoelectric element 51 of each element in advance by solder or the like, or a piezoelectric adhesive of each element is used by using a conductive adhesive. For example, a method of electrically connecting the 51 upper electrodes 52 along the depth direction Y may be used.

  Finally, after wiring, the transducer unit 250 is placed on the bent piezoelectric element 51 shown in FIG. 26 via the backing material 9 in the housing 10, and then the acoustic unit 250 is acoustically placed on the second acoustic matching layer 55. By forming the lens 6, the ultrasonic transducer 200 is formed.

  According to such a configuration, even if the ultrasonic transducer 200 is provided with the plurality of columnar portions 57c, the piezoelectric element 51, and the first acoustic matching layer 54 in an array shape, the additional member 57 is not added as described above. Since it functions similarly to the member 7, the same effect as the ultrasonic transducer 100 of the fourth embodiment described above can be obtained.

  In the present embodiment, since the plurality of recesses 57h are formed in parallel to the width direction X, variation in vibration characteristics can be suppressed in each element unit described above, and therefore, higher performance is achieved. A homogeneous ultrasonic transducer 200 can be formed. Other effects are the same as those of the fourth embodiment described above.

(Ninth embodiment)
FIG. 27 shows a state in which a plurality of grooves intersecting at an angle other than 90 ° are formed in the plurality of recesses in the width direction with respect to the additional member, the piezoelectric element, and the first acoustic matching layer in FIG. 28 is a top view of the additional member of FIG. 27 as viewed from the direction of IIXVIII in FIG. 27, and FIG. 29 is an enlarged perspective view of one columnar portion of FIG.

  Compared with the method of manufacturing the ultrasonic transducer of the eighth embodiment shown in FIGS. 22 to 26 described above, the manufacturing method of the ninth embodiment has an additional member, a piezoelectric element, and a first acoustic matching. The difference is that a plurality of grooves are formed in the width direction intersecting the plurality of recesses at an angle other than 90 ° with respect to the layer. As a result, the shape of each formed columnar part is different.

  Therefore, only this difference will be described, the same reference numerals are given to the same components as those in the eighth embodiment, and description thereof will be omitted.

  In the present embodiment, as shown in FIG. 27, the depth direction Y so as to penetrate the additional member 57, the piezoelectric element 51, and the first acoustic matching layer 54 shown in FIG. As shown in FIG. 28, the dicing saw blade 60 is used to cross the plurality of grooves 63 ′ having a set interval with the plurality of recesses 57 h at an angle θ other than 90 °. Form along X.

  Specifically, as shown in FIG. 28, the plurality of grooves 63 ′ are inclined in the Yb direction as they go in the Xa direction, and each of the grooves 63 ′ parallel to the depth direction Y and in the Xa direction, Each groove 63′b is inclined in the Ya direction and is parallel to the depth direction Y. The grooves 63a ′, 63b ′, 63a ′, 63b ′,... To form. The crossing angle θ of the grooves 63a ′ and 63b ′ with respect to the plurality of recesses 57h is the same. In the present embodiment also, the groove 63 ′ is not formed in the second acoustic matching layer 55.

  As a result, in the additional member 7, a plurality of columnar portions 57 c ′ are formed in an array in the width direction X and the depth direction Y.

  Therefore, as shown in FIG. 29, one columnar portion 57c 'is formed in a shape in which the width in the depth direction Y differs in the width direction X (Y1 <Y2 <Y3). Each columnar portion 57 c ′ has the configuration shown in FIG. 29, and the size in the width direction X and the depth direction Y is different for each columnar portion 57 c ′.

  According to such a configuration, as in the second embodiment described above, vibration in the direction M that falls in the width direction X and the depth direction Y is less likely to occur in each columnar portion 57c ′, and the height direction Since it becomes easy to vibrate to Z, the vibrator sensitivity in the ultrasonic vibrator 200 is improved.

  In addition, since the sizes in the width direction X and the depth direction Y are different for each columnar portion 57c ′, the vibration in the falling direction M is different for each columnar portion 57c ′. In this case, since the resonance frequency in the direction M becomes broad, it becomes difficult to vibrate in the direction M, and hence it becomes easy to vibrate in the height direction Z, so that the vibrator sensitivity in the ultrasonic vibrator 200 is improved. Other effects are the same as those of the above-described eighth embodiment.

  Note that the ultrasonic transducer 100 in the first to seventh embodiments and the ultrasonic transducer 200 in the eighth and ninth embodiments as described above are provided in, for example, an ultrasonic endoscope. Hereinafter, the configuration of the ultrasonic endoscope provided with the radial ultrasonic transducer 200 will be described with reference to FIGS. 30 to 33.

  30 is a diagram showing the appearance of the ultrasonic endoscope, FIG. 31 is an enlarged perspective view showing the ultrasonic vibration part provided at the distal end of the insertion part of the ultrasonic endoscope in FIG. 30, and FIG. 32 is a cross-sectional view of the ultrasonic vibration section taken along line IIIXII-IIIXII in FIG. 31, and FIG. 33 is a cross-sectional view of the ultrasonic vibration section taken along line IIIXIII-IIIXIII in FIG.

  The ultrasonic endoscope 80 is extended from the elongated insertion portion 82 to be inserted into the subject, an operation portion 83 provided at the proximal end of the insertion portion 82 in the insertion direction S, and the operation portion 83. A main part is configured by a universal cord 84 having flexibility and a connector 85 provided at an extended end of the universal cord 84.

  The connector 85 is provided with a light source connector 85a, an electrical connector 85b, an ultrasonic connector 85c, a suction base 85d, and an air / water supply base 85e.

  A light source device for supplying illumination light is detachably attached to the light source connector 85a, and a video processor for performing various signal processing and the like via a signal cable is detachably attached to the electrical connector 85b.

  Further, the ultrasonic observation apparatus can be freely attached to and detached from the ultrasonic connector 85c via an ultrasonic cable 87 connected to the ultrasonic observation apparatus, and a suction pump is attached to and detached from the suction base 85d via a suction tube. Further, a water supply tank can be attached to and detached from the air / water supply base 85e via an air / water supply tube.

  The insertion portion 82 includes, in order from the distal end side in the insertion direction S, a distal end portion 82a, a bending portion 82b configured to be able to bend in the vertical and horizontal directions, and a flexible tube portion that is long and flexible. 82c is continuously provided.

  Although not shown, an illumination lens, an observation lens, a channel opening, and the like are provided at a set position on the outer peripheral side surface of the distal end portion 82a. Furthermore, an imaging unit that captures an image observed by the observation lens is provided in the distal end portion 82a.

  An ultrasonic vibration unit 86 is provided at a position closer to the distal end side in the insertion direction S than the illumination lens, observation lens, and channel opening of the distal end portion 82a.

  As shown in FIGS. 30 and 31, the ultrasonic vibration unit 86 includes the above-described ultrasonic vibrator 200 in a cap 86 c made of, for example, cylindrical polyethylene with a closed end.

  As shown in FIG. 32, the ultrasonic transducer 200 is a radial type ultrasonic transducer wound in a cylindrical shape so that one end 57y1 and the other end 57y2 in the depth direction Y of the additional member 57 are in contact with each other. Yes.

  In the ultrasonic transducer 200 of the ninth embodiment described above, the one end 57y1 and the other end 57y2 are inclined along the width direction X so as to intersect with the plurality of recesses 57h at a predetermined angle. However, even in such a configuration, since the one end 57y1 and the other end 57y2 along the width direction X are positioned in parallel to the depth direction Y, the one end 57y1 and the other end 57y2 are wound even if wound. The abutting surface can be adjusted to be clean and can be formed in a cylindrical shape.

  Further, ring-shaped support members 88 are bonded and fixed to the end faces 57sa and 57sb in the insertion direction S of the additional member 57. The support member 88 has a function of maintaining the strength of the ultrasonic transducer 200 against an external force applied to the acoustic lens 56. The ultrasonic transducer 200 can be easily assembled by positioning the additional member 57 with respect to the support member 88 using the end faces 57sa and 57sb.

  Further, a support member 89 having a T-shaped cross section in the insertion direction S is inserted into the inner peripheral surface side of the support member 88 in the radial direction K. As shown in FIG. A signal cable 90 inserted from the 85 ultrasonic connector 85c through the universal cord 84, the operation portion 83, and the insertion portion 82 to the distal end portion 82a is fitted.

  In the ultrasonic transducer 200, the upper electrode lead portion 30 of the upper electrode 52 is connected to the support member 89 through the second wiring 14 and is connected to the GND wiring of the cable 90 through the support member 89. Yes. The other end of the first wiring 13 having one end connected to the lower electrode connecting portion 11 of the lower electrode 53 is electrically connected to the support member 89, and the support member 89 and the signal cable 90 are electrically connected by the wiring 99. Thus, the lower electrode 53 is electrically connected to the signal cable 90.

  As described above, the ultrasonic transducer 200 is fixed in the cap 86c. The ultrasonic transducer provided in the cap 86c may be the ultrasonic transducer 100 shown in the first to seventh embodiments, and is not limited to the radial type ultrasonic transducer. Needless to say, it may be a convex ultrasonic transducer.

DESCRIPTION OF SYMBOLS 1 ... Piezoelectric element 1j ... Upper surface 1s ... Side surface 1sa ... Side surface 1sb ... Side surface 1t ... Bottom surface 2 ... Upper electrode 3 ... Lower electrode 4 ... 1st acoustic matching layer 5 ... 2nd acoustic matching layer 6 ... Acoustic lens 7 ... Addition Member 7c ... Columnar part 7ct ... End 7e1 ... Extension part 7e2 ... Extension part 7h ... Recess 7hm ... Bottom 7j ... Top 7p ... Recess 7r ... Connecting part 7sa ... Side 7sb ... Side 7t ... Bottom 8 ... Filler 9 ... Backing material 10 ... Housing 11 ... Lower electrode connection part 12 ... Upper electrode connection part 13 ... First wiring 14 ... Second wiring 16 ... Adhesive 17 ... Dicing saw blade 17r ... R surface 19 ... Adhesive 21 ... Piezoelectric material 21j ... Upper surface 21t ... Bottom 22 ... Upper electrode 23 ... Lower electrode 24 ... Piezoelectric material 24t ... Bottom surface 25 ... Piezoelectric element unit 25c ... Columnar part 25h ... Recess 25j ... Upper surface 25r ... Connection part 25t ... Bottom surface 26 ... First side electrode 27 ... Second side electrode 30 ... Upper electrode lead-out part 34 ... Power supply 35 ... Conductive adhesive 36 ... Conductive adhesive 42 ... Electrode 43 ... Electrode 44 ... Lower electrode Lead-out part 45 ... Upper electrode lead-out part 51 ... Piezoelectric element 51j ... Upper surface 51t ... Bottom face 52 ... Upper electrode 53 ... Lower electrode 54 ... First acoustic matching layer 55 ... Second acoustic matching layer 56 ... Acoustic lens 57 ... Additional member 57c ... Columnar part 57h ... Recessed part 57hm ... Bottom face 57sa ... Each end face 57t ... Bottom face 57y1 ... One end 57y2 ... Other end 58 ... Filler 60 ... Dicing saw blade 63 ... Groove 63 '... Groove 63a' ... Groove 63b '... Groove 80 ... Ultrasound endoscope 82 ... Insertion part 82a ... Tip part 82b ... Bending part 82c ... Flexible tube part 83 ... Operation part 84 ... Universal cord 85 ... Connector 85a Light source connector 85b ... Electric connector 85c ... Ultrasonic connector 85d ... Suction cap 85e ... Air supply / water supply cap 86 ... Ultrasonic vibrator 86c ... Cap 87 ... Ultrasonic cable 88 ... Support member 89 ... Support member 90 ... Signal cable 91 ... Housing 99 ... Wiring 100 ... Ultrasonic vibrator 130 ... Acoustic matching layer unit 150 ... Oscillator unit 150 '... Oscillator unit 200 ... Ultrasonic vibrator 230 ... Acoustic matching layer unit 250 ... Oscillator unit D ... Dotted line H ... Area K ... radial direction M ... tilting direction S ... insertion direction X ... width direction Y ... depth direction Z ... height direction ZU ... ultrasonic radiation direction θ ... crossing angle

Claims (21)

A piezoelectric element;
An upper electrode disposed on at least the upper surface of the piezoelectric element;
An acoustic matching layer disposed on the upper surface of the upper electrode;
A lower electrode disposed at least on the bottom surface of the piezoelectric element;
Below the piezoelectric element in the height direction connecting the upper surface and the bottom surface, at least a portion of the piezoelectric element is arranged to be in contact with the lower electrode, and is below the acoustic impedance of the piezoelectric element, the acoustic matching layer An additional member comprising a plurality of columnar portions having an acoustic impedance equal to or higher than the acoustic impedance;
A filler that is filled between the plurality of columnar portions and is softer than the columnar portions; and
Under the piezoelectric element in the height direction, a backing material arranged to cover the additional member from below,
An ultrasonic transducer comprising:   The ultrasonic transducer according to claim 1, wherein an acoustic impedance of the additional member is the same as an acoustic impedance of the piezoelectric element.   The ultrasonic transducer according to claim 2, wherein the additional member is made of the same piezoelectric material as a piezoelectric material that is a base material of the piezoelectric element.   The ultrasonic transducer according to claim 3, wherein the additional member is non-piezoelectric because it is not polarized.   In the plurality of columnar portions, the additional member is connected to each of the end portions in the height direction on the lower electrode side in a width direction orthogonal to the height direction. The ultrasonic transducer according to claim 1, wherein each has a comb shape.   In the additional member, a surface in contact with the filler of each portion connecting the end portions of the columnar portions in the width direction is formed in a shape that connects the columnar portions with a curvature. The ultrasonic transducer according to claim 5, wherein:   The ultrasonic vibration according to claim 1, wherein a width of the additional member in a width direction orthogonal to the height direction is smaller than a width of the piezoelectric element in the width direction. Child. The additional member includes the plurality of columnar portions, and extending portions located on one side and the other side in the width direction with respect to the plurality of columnar portions,
A lower electrode lead portion from which the lower electrode to which the first wiring is electrically connected is drawn is provided on the surface in contact with the backing material on the one side in the extending portion,
The upper electrode lead portion from which the upper electrode to which the second wiring is electrically connected is drawn is provided on a surface of the extension portion that is in contact with the backing material on the other side. Item 7. The ultrasonic transducer according to Item 5 or 6. The additional member is positioned below the piezoelectric element at the center in the width direction orthogonal to the height direction, and the first wiring is electrically connected to a region of the lower electrode where the additional member is not disposed. A lower electrode connection part is provided,
In the bottom surface of the piezoelectric element, an upper electrode lead portion from which the upper electrode to which the second wiring is electrically connected is drawn is provided in a region where the lower electrode is not disposed. The ultrasonic transducer according to claim 1.   The ultrasonic transducer according to claim 9, wherein the upper electrode and the lower electrode are polarized only in a region where the upper electrode and the lower electrode face each other.   In the additional member, a surface in contact with the filler in each portion connecting the end portions of the columnar portions in the width direction is more central in the width direction than surfaces positioned on one side and the other side. The ultrasonic transducer according to any one of claims 5 to 10, wherein the surface to be positioned is recessed toward the piezoelectric element side.   In the plurality of columnar portions, the width in the width direction of the columnar portion located in the center of the width direction orthogonal to the height direction is greater than the width of the columnar portion located on one side and the other side in the width direction. The ultrasonic transducer according to claim 1, wherein the ultrasonic transducer is small.   Each of the columnar portions is formed in a shape in which the depth in the depth direction orthogonal to both the height direction and the width direction orthogonal to the height direction is different in the width direction. The ultrasonic transducer according to any one of 1 to 12.   The ultrasonic wave according to any one of claims 1 to 13, wherein an acoustic matching layer that is at least partially in contact with the upper electrode is disposed above the height direction of the upper electrode. Vibrator. A polarized first piezoelectric material;
An upper electrode disposed on an upper surface of the first piezoelectric material;
A lower electrode disposed on a bottom surface of the first piezoelectric material;
A second piezoelectric material having the same acoustic impedance as the first piezoelectric material, at least part of which is in contact with the lower electrode, below the first piezoelectric material in the height direction connecting the upper surface and the bottom surface When,
The first piezoelectric material and the second piezoelectric material are electrically connected to the lower electrode provided on one side surface in the width direction perpendicular to the height direction, and the first wiring is A first side electrode electrically connected;
The first piezoelectric material and the second piezoelectric material are electrically connected to the upper electrode provided on the other side surface in the width direction, and the second wiring is electrically connected. A second side electrode;
A plurality of recesses formed on the bottom surface of the second piezoelectric material;
A filler that is filled in the recess and is softer than the columnar part; and
Under the piezoelectric element in the height direction, a backing material arranged to cover the first piezoelectric material and the second piezoelectric material from below,
An ultrasonic transducer comprising: Forming an upper electrode on at least the upper surface of the piezoelectric element, and forming a lower electrode on at least the bottom surface; and
An adhesion step of adhering an additional member having the same acoustic impedance as that of the piezoelectric element via an adhesive to the lower electrode;
A columnar portion forming step of forming a plurality of columnar portions by forming a plurality of concave portions on a surface opposite to a surface bonded to the lower electrode of the additional member;
A method for producing an ultrasonic transducer, comprising:   The method of manufacturing an ultrasonic transducer according to claim 16, further comprising a step of bonding an acoustic matching layer to the upper electrode after forming the electrode and before the bonding step. In the columnar part forming step, with respect to the additional member, the plurality of recesses are set in a depth direction perpendicular to both the height direction and the width direction perpendicular to the height direction with a set interval. It is a step of forming from one end to the other end in the depth direction,
After the columnar portion forming step, a filler filling step of filling the concave portion with a softer filler than the columnar portion along the depth direction;
A groove forming step of forming a plurality of grooves with a set interval in the depth direction so as to penetrate at least the additional member and the piezoelectric element in the height direction;
A bending step of bending the additional member, the piezoelectric element, and the acoustic matching layer from the groove as a starting point by pressing the center in the depth direction and the width direction downward in the height direction. When,
The method for manufacturing an ultrasonic transducer according to claim 17, comprising:   The method of manufacturing an ultrasonic transducer according to claim 18, wherein the groove forming step is a step of forming a groove so as to be orthogonal to the concave portion. 19. The method of manufacturing an ultrasonic transducer according to claim 18, wherein the groove forming step is a step of forming a groove so as to intersect with the concave portion at an angle other than 90 degrees.   An ultrasonic endoscope comprising the ultrasonic transducer according to any one of claims 1 to 15.

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