JP6552149B1 - Ultrasonic transducer and manufacturing method thereof - Google Patents

Abstract

An ultrasonic transducer according to the present invention includes an elastic plate that can vibrate in a plate thickness direction, a plurality of piezoelectric elements fixed in parallel to a first surface of the elastic plate, and a polymer material that covers the plurality of piezoelectric elements And the elastic plate includes a plurality of vibration regions to which the plurality of piezoelectric elements are respectively attached, a plurality of low rigidity regions surrounding each of the plurality of vibration regions, and a plurality of low rigidity regions. A plurality of constraining regions surrounding each other, and a boundary region that divides one constraining region and an outer region positioned radially outward from the one constraining region, and the boundary region includes the one constraining region and the one constraining region A slit portion for dividing the outer region; and a bridge portion for mechanically connecting the one constraining region to the outer region. The sealing member is a plurality of cylindrical portions surrounding each of the plurality of piezoelectric elements in a plan view, and a plurality of cylindrical shapes joined to the first surface of the elastic plate at a position where the base end surface straddles the slit portion. A plurality of closed portions that respectively close the free ends of the plurality of cylindrical portions, and a filling portion that extends from the base end surface of the cylindrical portion to the inside of the slit portion.

Description

  The present invention relates to an ultrasonic transducer that includes a plurality of piezoelectric elements arranged in parallel and can be suitably used as a phased array sensor, and a manufacturing method thereof.

  An ultrasonic transducer in which a plurality of vibrators including a piezoelectric element and a diaphragm are arranged in parallel is suitably used as a phased array sensor for detecting the shape of an object or detecting the presence or absence of an object over a wide range. In this case, the following items are required for the ultrasonic transducer.

  That is, in order to suppress the occurrence of the grating lobe phenomenon between the plurality of vibrators, the arrangement pitch of the plurality of vibrators needs to be ½ or less of the wavelength λ of the ultrasonic wave emitted by the vibrators. There is.

  On the other hand, in order to detect an object several meters ahead, it is necessary to set the frequency of the ultrasonic wave radiated by the vibrator used for the ultrasonic transducer to a low frequency of about 40 kHz.

  Since the wavelength λ of the ultrasonic wave with a frequency of 40 kHz is 8.6 mm, in order to suppress the occurrence of the grating lobe phenomenon while setting the frequency of the ultrasonic wave emitted by the oscillator to 40 kHz, the arrangement pitch of the plurality of oscillators It is necessary to make 8.6 mm / 2 = 4.3 mm or less.

  However, at present, the diameter of a vibrating body capable of emitting ultrasonic waves of 40 kHz is about 10 mm, and therefore, it is impossible to satisfy the above-described demand using the current vibrating body.

  In this regard, a configuration (hereinafter referred to as a first conventional configuration) in which a waveguide (acoustic tube) is combined with a normal vibrating body that radiates 40 kHz ultrasonic waves has been proposed.

  In the first conventional configuration, the one end side opening of the waveguide is connected to each of the plurality of vibrators arranged in parallel, and the vibrator radiates the arrangement pitch of the other end side openings of the waveguide. It is comprised so that it may be set to 1/2 or less of the wavelength of an ultrasonic wave.

However, in the first conventional configuration, there is a problem that the overall size of the sensor including the waveguide increases.
Also, there is a problem that the reflection of the ultrasonic waves generated in the waveguide adversely affects the radiation profile of the ultrasonic waves.

  As a configuration different from the first conventional configuration, an ultrasonic transducer (hereinafter, referred to as a second conventional configuration) including a plurality of vibrators manufactured using MEMS (Micro Electro Mechanical Systems) technology has been proposed (hereinafter, referred to as a second conventional configuration). For example, see Patent Documents 1 and 2 below).

  In the second conventional configuration, the size of the vibrating plate vibrated by the piezoelectric element can be set to 400 to 800 μm, and a plurality of vibrating bodies can be arranged at an arrangement pitch of λ / 2 or less.

However, in the second conventional configuration, the size of the diaphragm becomes too small, and it becomes difficult to generate a low frequency ultrasonic wave of about 40 kHz required to detect an object several meters away.
In addition, there is also a problem that the manufacturing cost increases with the complexity of the manufacturing process.

JP 2010-164331 A JP 2013-046086 A

The present invention is made in view of such prior art, and is an ultrasonic transducer provided with a plurality of piezoelectric elements arranged in parallel, and an array of a plurality of vibrators formed by each of the plurality of piezoelectric elements. An object of the present invention is to provide an ultrasonic transducer capable of preventing vibration propagation between the plurality of vibrating bodies as much as possible while narrowing the pitch.
Another object of the present invention is to provide a manufacturing method capable of efficiently manufacturing the ultrasonic transducer.

  In order to achieve the object, an elastic plate having a first surface and a second surface facing the one side and the other side in the plate thickness direction, respectively, and in parallel with the first surface of the elastic plate can vibrate in the plate thickness direction. A plurality of piezoelectric elements fixed in a state, and a sealing member made of a polymer material provided on the first surface of the elastic plate so as to cover the plurality of piezoelectric elements; A plurality of vibration regions on which the piezoelectric elements are mounted, a plurality of low rigidity regions respectively surrounding the plurality of vibration regions in plan view, and a plurality of restraint regions respectively surrounding the plurality of low rigidity regions in plan view; The low-rigidity region includes the boundary region that defines one restraint region and an outer region located radially outward from the one restraint region, and the low-rigidity region is the vibration region located radially inward of the region. And the restraint area located radially outward of the area The boundary region has a slit portion for dividing one restraint region and the outer region, and a bridge portion for mechanically coupling the one restraint region to the outer region. And the sealing member is a plurality of cylindrical portions disposed so as to surround each of the plurality of piezoelectric elements in plan view, the first end surface of the elastic plate being at a position straddling the slit portion. A plurality of cylindrical portions joined to the surface, a plurality of closed portions respectively closing the free end sides of the plurality of cylindrical portions, and a filling portion extending from the proximal end surface of the cylindrical portion to the inside of the slit portion An ultrasonic transducer is provided.

According to the ultrasonic transducer in accordance with the present invention, while narrowing the arrangement pitch of the plurality of vibration regions, it is possible to propagate vibrations through the elastic plate between the plurality of vibrators by the slits in the boundary region. It can be prevented or reduced.
Therefore, low frequency ultrasonic waves can be effectively emitted while effectively preventing or reducing mutual interference among the plurality of piezoelectric elements.

Furthermore, in the ultrasonic transducer, the vibration area is flexibly supported via the low rigidity area, and a low resonance frequency can be realized even if the area of the vibration area is reduced. Sound pressure can be increased.
Further, in the ultrasonic transducer, since the slit filling portion of the sealing member made of a polymer material is filled in the slit portion, the posture stabilization of the restraint region can be achieved, and the ultrasonic transducer Reliability can be improved.

In one form, the said sealing member is formed with the 1st polymer material, and is formed with the 1st sealing member which integrally forms the said filling part and the said cylindrical part, and a 2nd polymer material, The said obstruction | occlusion And a second sealing member forming the portion.
Preferably, the first polymeric material has a viscosity lower than that of the second polymeric material based on the state before curing.

  In another embodiment, the plurality of cylindrical parts, the closed part and the filling part are integrally formed of the same polymer material.

In one form, the low stiffness region comprises a groove that opens to the first surface of the elastic plate.
According to such a configuration, the groove can be used as an alignment mark when the piezoelectric element is mounted in the vibration region.

In another embodiment, the low-rigidity region includes an opening that divides the vibration region and the constraining region, and a connection portion that connects the vibration region and the constraining region. The parts and the connection parts are alternately provided along the outer peripheral edge of the vibration area.
According to such a configuration, the opening and the connection can be used as alignment marks when the piezoelectric element is mounted in the vibration area.

  In still another embodiment, the low-rigidity region is a concave thin region in which the first surface is closer to the second surface than the first surface of the vibration region and the restraining region.

In this case, the piezoelectric element includes a central portion overlapping with the vibration region in a plan view, and an extending portion extending radially outward from the central portion and terminating in the low rigidity region in a plan view The lower surface electrode layer in the central portion is fixed to the first surface of the vibration region by an insulating adhesive, and the lower surface electrode layer in the extension portion is a first surface of the low rigidity region by a conductive adhesive. Electrically and mechanically connected to the surface.
According to such a configuration, the outer peripheral edge of the low-rigidity region can be used as an alignment mark when the piezoelectric element is mounted on the vibration region.

  Preferably, the bottom surface of the thin region is provided with a ridge lower than the first surface of the vibration region, and co-operating with the inner surface of the thin region to form an adhesive retention region. The conductive adhesive that electrically and mechanically connects the lower surface electrode layer in the extending portion and the first surface of the low-rigidity region is provided in the adhesive retention region.

  According to such a configuration, the insulating adhesive for mechanically joining the central portion of the piezoelectric element and the vibration region, and the lower electrode layer of the extension portion of the piezoelectric element and the low rigidity region are electrically connected. Mixing against the meaning of the conductive adhesive can be effectively prevented, and the reliability of electrical connection between the lower electrode layer of the piezoelectric element and the elastic plate can be improved.

  In the various configurations, preferably, the ultrasonic transducer according to the present invention is fixed to the first surface of the elastic plate so as to open the first surface of the vibration region, the low rigidity region and the boundary region. Mass members can be provided.

  According to such a configuration, it is possible to suppress the vibration of the restraint region, reduce the cross stroke between the plurality of vibration regions, and increase the vibration amplitude of the vibration region to increase the sound pressure of the generated sound wave. .

  Preferably, the mass member and the cylindrical portion are provided such that the upper end portion is separated from the first surface of the elastic plate than the upper surface of the piezoelectric element, and the closed portion is an upper surface electrode layer of the piezoelectric element A housing space for covering the piezoelectric element, which covers the mass member and the cylindrical portion so as to have a gap therebetween, and is surrounded by the first surface of the elastic plate, the mass member, and the closing portion; Is filled with a sound absorbing material made of foamable resin.

  According to such a configuration, sound wave leakage from the side of the first surface of the elastic plate can be effectively suppressed.

  In one form, the ultrasonic transducer according to the present invention is a protective member joined to the second surface of the elastic plate, comprising a protective member having an opening that opens the vibration area outward. it can.

  According to such a configuration, external contact with the elastic plate can be effectively prevented, and damage to the elastic plate can be effectively prevented.

  In one form provided with the said protection member, Preferably, the rigid protection board which has a through-hole in the position corresponding to the said opening is joined to the outer end surface of the said protection member.

  According to such a configuration, it is possible to effectively prevent damage to the surface of the protective member and to suppress vibration of the surface of the protective member.

  In one mode provided with the protective member, preferably, the ultrasonic transducer according to the present invention can comprise a rigid reinforcing plate fixed to the outer surface of the closed portion.

In the configuration including the protection member, the protection plate, and the reinforcing plate, preferably, the protection plate is fixed to an outer surface of the protection member, and extends outward from the center portion in the plate surface direction. The reinforcing plate is provided with a central portion fixed to the outer surface of the closed portion, and an extended portion extending outward in the plate surface direction from the central portion. .
And the extension part of the said reinforcement board and the extension part of the said guard plate are connected via the spacer.

  According to such a configuration, deformation of the elastic plate due to external force can be more effectively suppressed, and damage to the elastic plate and the piezoelectric element can be effectively prevented or reduced.

A protective container can be provided instead of the protective plate.
The protective container extends along the outer surface of the protective member, and surrounds an end wall portion provided with a through hole at a position corresponding to the opening of the protective member, and an outer periphery of the protective member and the elastic plate. And a peripheral wall extending from the end wall.
In this case, the reinforcing plate is connected to the peripheral wall portion so as to close the free end opening of the peripheral wall portion of the protective container while covering the outer surface of the closing portion.

  Also with such a configuration, deformation of the elastic plate due to external force can be more effectively suppressed, and damage to the elastic plate and the piezoelectric element can be effectively prevented or reduced.

  For example, the reinforcing plate is provided with a through hole that communicates the inner surface and the outer surface.

  In the various configurations, the elastic plate is a conductive metal plate, and the piezoelectric element has a piezoelectric body, and a pair of upper and lower electrode layers disposed on both sides in the thickness direction of the piezoelectric body. It is said.

  In this case, preferably, the elastic plate is provided with a wiring body including an insulating layer provided on the first surface and a plurality of wiring conductors stacked on the insulating layer, and the lower surface electrode layer is conductive. The upper surface electrode layer is electrically connected to the corresponding wiring conductor by a conductive adhesive or solder, and is mechanically and electrically bonded to the first surface of the elastic plate by a conductive adhesive.

  According to such a configuration, electrical connection between the piezoelectric element and the external voltage can be realized with a simple structure.

  Preferably, an insulating adhesive is interposed between the conductive adhesive or solder electrically connecting between the upper surface electrode layer and the corresponding wiring conductor and the first surface of the elastic plate.

  According to such a configuration, it is possible to effectively prevent the upper surface electrode layer and the lower surface electrode layer from short circuiting due to the conductive adhesive or the solder unintentionally contacting the first surface of the elastic plate. Can do.

  In the above-described various configurations, for example, the plurality of constraining areas is a constraining area group formed by m (m is an integer of 1 or more) constraining areas arranged along the first plate surface direction of the elastic plate. It is assumed that n rows (n is an integer of 1 or more) are provided in the second plate surface direction orthogonal to the first plate surface direction, and m × n constrained regions appear by being provided.

  In this case, preferably, the slit portions are located on both sides in the second plate surface direction of one piezoelectric element mounted in the vibration region in the one restraint region, and extend along the first plate surface direction. A first plate surface direction slit, and a pair of second plate surface direction slits located on both sides of the first piezoelectric element in the first plate surface direction and extending along the second plate surface direction, The pair of first plate surface direction slits is longer than the first plate surface direction length of the one piezoelectric element, and the pair of second plate surface direction slits is longer than the second plate surface direction length of the pair of piezoelectric elements It is long, and it is comprised so that four places demarcated by between the end parts of the 1st plate surface direction slit which adjoins the peripheral direction, and the 2nd plate surface direction slit may form the above-mentioned bridge part.

  More preferably, a single common slit is provided between adjacent constraining areas, and the single common slit defines the outer peripheral edges of both of the adjacent constraining areas.

  Further, according to the present invention, an elastic plate having first and second surfaces respectively facing one side and the other side in the thickness direction and capable of vibrating in the thickness direction, each having a piezoelectric main body and the thickness direction of the piezoelectric main body A plurality of piezoelectric elements having an upper surface electrode layer and a lower surface electrode layer disposed on both sides, wherein the lower surface electrode layer is fixed to the first surface of the plurality of vibration regions provided in the elastic plate; A wiring body including a plurality of wiring conductors provided on an insulating layer and electrically connected to upper surface electrode layers of the plurality of piezoelectric elements, and a first surface of the elastic plate so as to cover the plurality of piezoelectric elements A sealing member made of a polymer material, and a protective member fixed to the second surface of the elastic plate, the protective member having an opening for opening the vibration area outward. The elastic plate has the plurality of vibration regions in plan view, respectively. A plurality of low rigidity regions, a plurality of restraint regions respectively surrounding the plurality of low rigidity regions in a plan view, a restraint region in a plan view and an outer region radially outward from the one restraint region And a boundary portion that mechanically connects the first restriction region to the outer region, and the slit portion that divides the first restriction region and the outer region. And the sealing member is a plurality of cylindrical portions respectively surrounding the plurality of vibration areas in a plan view, and the base end surface is joined to the first surface of the elastic plate at a position including the boundary area A plurality of cylindrical portions, a plurality of closed portions respectively closing the openings on the free end side of the plurality of cylindrical portions, and a filling portion extending from the proximal end surface of the cylindrical portion to the inside of the slit portion; How to make an ultrasonic transducer A step of preparing a conductive elastic plate forming body for forming the elastic plate, a wiring body setting step for installing the wiring body, and etching the elastic plate forming body to form the slit portion. And an elastic plate etching step of forming the low rigidity region, a piezoelectric element mounting step of adhering lower surface electrode layers of the plurality of piezoelectric devices to the first surface of the plurality of vibration regions with a conductive adhesive, and Electrically connecting the front end portion of the wiring conductor with the upper surface electrode layer of the corresponding piezoelectric element with a conductive adhesive or solder, and opening the vibration area outward through the opening. The method further includes a protection member installation step of fixing the protection member to the second surface of the elastic plate so as to close the second surface side of the slit portion, and a sealing member installation step of mounting the sealing member, Body setting And the elastic plate etching step and the piezoelectric element mounting step can be performed in any order, and the sealing member setting step is a first sealing member integrally forming the filling portion and the cylindrical portion. And a second sealing member installation step of installing a second sealing member forming the closed portion, wherein the first sealing member installation step includes A process of installing a cylindrical part formwork that defines an area where a part is to be provided in a state in which the upper part is open, and a first height in the cylindrical part formwork from the side of the first surface of the elastic plate A first method of manufacturing an ultrasonic transducer is provided which includes the steps of applying and curing a molecular material.

  According to such a first manufacturing method, an ultrasonic transducer having the above-described configuration can be manufactured at a low cost and with a high yield.

  In the first manufacturing method, before or after the first sealing member installation step, and before the second sealing member installation step, a foamable resin is applied to surround the piezoelectric element. And a sound absorbing material installing step of installing the sound absorbing material by curing.

  For example, in the first sealing member installation step, the first sealing member is installed such that the upper end portion of the cylindrical portion is positioned above the upper surface of the piezoelectric element, and the sound absorbing material The installation step can be performed after the first sealing member installation step and before the second sealing member installation step.

  According to such a manufacturing method, the first sealing member can be used as a mold for a sound absorbing material, and the sound absorbing material can be installed with good controllability.

  In the first manufacturing method, preferably, the second sealing member installation step is higher than the first polymer material on the upper surface of the cylindrical portion and the sound absorbing material on the basis of the state before curing. A second polymeric material of viscosity is applied and configured to cure.

  The present invention also includes an elastic plate having a first surface and a second surface facing the one side and the other side in the plate thickness direction, respectively, and capable of vibrating in the plate thickness direction, respectively, the piezoelectric body, and the thickness direction of the piezoelectric body. A plurality of piezoelectric elements having an upper surface electrode layer and a lower surface electrode layer disposed on both sides, wherein the lower surface electrode layer is fixed to the first surface of the plurality of vibration regions provided in the elastic plate; A wiring body including a plurality of wiring conductors provided on the insulating layer and electrically connected to the upper surface electrode layers of the plurality of piezoelectric elements; a mass member fixed to the first surface of the elastic plate; A sealing member made of a polymer material provided on the first surface of the elastic plate so as to cover a plurality of piezoelectric elements, and a protective member fixed to the second surface of the elastic plate, wherein the vibration region is A protective member provided with an opening that opens to the outside, the elastic plate, A plurality of low rigidity regions respectively surrounding the plurality of vibration regions in a planar view, a plurality of constrained regions respectively surrounding the plurality of low rigid regions in a planar view, and a base region surrounding the entire plurality of constrained regions in a planar view And a boundary area located between one adjacent restriction area and the other restriction area and between the adjacent restriction area and the base area, which demarcates the plurality of restriction areas, and the boundary area Has a slit portion for dividing the one constraining region from the periphery and a bridge portion for mechanically connecting the one constraining region to the periphery, and the mass members are respectively fixed to the plurality of constraining regions A plurality of restraining area mass members and a base area mass member fixed to the base area, wherein the sealing member surrounds the plurality of vibration areas in plan view. A plurality of cylindrical portions joined to the first surface of the elastic plate at a position where the base end surface includes the boundary area, and an opening on the free end side of the plurality of cylindrical portions. What is claimed is: 1. A method of manufacturing an ultrasonic transducer, comprising: a plurality of closed parts that close and a filling part extending from the proximal end face of the cylindrical part to the inside of the slit part, wherein the conductive plate forms the elastic plate. A step of preparing an elastic plate forming body, a wiring body installing step of installing the wiring body, and an elastic plate etching step of etching the elastic plate forming body to form the slit portion and the low rigidity region And a piezoelectric element mounting step of adhering lower surface electrode layers of the plurality of piezoelectric elements to the first surface of the plurality of vibration regions with a conductive adhesive, and the piezoelectric element corresponding to the tips of the plurality of wiring conductors Conductive on top electrode layer An electrical connection step of electrically connecting by an adhesive or a solder, a process of fixing the mass member for the restriction area to each of the plurality of restriction areas, and a process for fixing the mass element for the base area to the base area A mass member installation step, and a protection member fixed to the second surface of the elastic plate so as to close the second surface side of the slit portion while opening the vibration area outward through the opening And a sealing member setting step of setting the sealing member, wherein the wiring member setting step, the elastic plate etching step and the piezoelectric element mounting step can be performed in any order, the mass member The installing step and the protecting member installing step can be performed in any order, and the sealing member installing step installs a first sealing member integrally forming the filling portion and the cylindrical portion. And a second sealing member installing step of installing a second sealing member forming the closed portion, wherein the first sealing member installing step includes a mass member for one restraint region adjacent to the first sealing member installing step. The first polymeric material is applied from the side of the first surface of the elastic plate between the other mass members for the restriction area and between the adjacent mass elements for the restriction area and the mass members for the base area, and cured. A second method of manufacturing an ultrasonic transducer configured to be provided is provided.

  According to the second manufacturing method, the ultrasonic transducer having the above-described configuration can be manufactured at a low cost and with a high yield.

  In the second manufacturing method, preferably, in the mass member installation step, the plurality of restraint region mass members, the base region mass member, and one adjacent restraint region mass member and another restraint region. A mass plate is provided that includes an inter-restraint area bridge that connects upper ends of mass members, and an inter-base area bridge that connects upper ends of adjacent restraining area mass members and base area mass members. Processing, securing the mass plate at a predetermined position on the first surface of the elastic plate, cutting the inter-restraint area bridge and the restraining area / base area bridge, the plurality of restraining area masses And a process of separating the member and the mass member for the base region.

  According to such a configuration, it is possible to simplify and speed up the installation process of the plurality of restriction region mass members and the base region mass member.

  For example, the process of preparing the mass plate includes the process of preparing a plate-like metal block having a thickness corresponding to the height of the restraint area mass member and the base area mass member, and one side of the metal block And a process of half-etching a region corresponding to the bridge between the constrained regions and the bridge between the constrained regions / base regions from the surface.

  In the second manufacturing method, before or after the first sealing member installing step, and before the second sealing member installing step, the second manufacturing method is performed in the space surrounded by one restraint area mass member. A sound absorbing material installing step of installing a sound absorbing material by applying and curing a foamable resin so as to surround the piezoelectric element can be provided.

  For example, the restraint region mass member has an upper end portion located above the upper surface of the piezoelectric element, and the sound absorbing material installation step is performed after the first sealing member installation step and the second sealing member installation step. 2 It can carry out before a sealing member installation process.

  In one form, the second manufacturing method is characterized in that the central portion polymerizes to the protective member in plan view, either before or after the protective member is fixed to the second surface of the elastic plate. A protective plate is provided which has an extending portion extending outward in the plate surface direction from the central portion, and provided with a through hole communicating the opening of the protective member outward, and the central portion of the protective plate is A protective plate installation step of fixing to the outer surface of the protective member in a state where the hole and the opening are aligned, a central portion overlapping with the elastic plate in plan view and an extension extending outward in the plate surface direction from the central portion A reinforcing plate is provided which has a recessed portion and is provided with a through hole communicating the inner surface and the outer surface, and connects the extending portion of the reinforcing plate and the extending portion of the protective plate via a spacer An installation step.

  In this case, in the second sealing member installation step, the second polymer material whose viscosity before curing is higher than that of the first polymer material is applied and cured through the through hole of the reinforcing plate. Configured.

  In another embodiment, the second manufacturing method extends along the outer surface of the protective member either before or after the protective member is fixed to the second surface of the elastic plate. Providing a protective container having an end wall portion provided with a through hole corresponding to the opening and a peripheral wall portion extending from the end wall portion so as to surround the outer periphery of the protective member and the elastic plate; A protective container setting step of fixing the end wall portion to the outer surface of the protective member with the opening aligned, and a through hole extending along the elastic plate and connecting the inner surface and the outer surface And a reinforcing plate installation step of connecting the reinforcing plate to the peripheral wall portion so as to close a free end opening of the peripheral wall portion of the protective container.

  In this case, in the second sealing member installation step, the second polymer material whose viscosity before curing is higher than that of the first polymer material is applied and cured through the through hole of the reinforcing plate. Configured.

  In the other embodiment, the peripheral wall portion of the protective container may surround the outer periphery of the protective member and the elastic plate in a state where there is a gap between the protective member and the outer periphery of the elastic plate.

  In this case, in the second sealing member installation step, the second polymer material is added to the region located above the elastic plate in plan view, and the peripheral wall portion of the protective container, the protective member, and the elastic plate It is comprised so that it may apply | coat also to the clearance gap between the outer periphery of.

  Alternatively, the peripheral wall portion of the protective container may surround the outer periphery of the protective member and the elastic plate in a state of being in contact with the outer periphery of the protective member and the elastic plate.

  In various configurations of the first and second manufacturing methods, the low rigidity region may be a groove opened to the side of the first surface provided along the outer peripheral edge of the vibration region, or the outside of the vibration region. It may be a plurality of openings provided along the peripheral edge, wherein a plurality of openings are left between the openings adjacent in the circumferential direction.

  In this case, the elastic plate etching step is configured to form the groove or the plurality of openings in the low rigidity region in addition to the formation of the slit portion.

  Instead, the low-rigidity region has a concave thin wall that opens to the first surface side where the first surface of the low-rigidity region is closer to the second surface than the first surface of the vibration region and the restraining region. The bottom surface of the thin area is a raised portion lower than the vibration area and the first surface of the constraining area, and forms an adhesive retention area in cooperation with the inner side surface of the thin area. A protruding portion is provided, and the piezoelectric element is overlapped with the vibration region in a plan view, and a central portion joined to the first surface of the vibration region by the insulating adhesive, and radially outward from the central portion And extending in the planar view and end in the low rigidity region, the extension portion being joined to the first surface of the low rigidity region by the conductive adhesive disposed in the adhesive retention region. The

  In this case, the elastic plate etching step includes a full etching process in which the elastic plate forming body is etched to form the slit portion, and a region corresponding to the low rigidity region from the first surface side. A half etching process is performed which performs half etching to form the low rigidity area which is a concave thin area.

  In the half etching process, the region corresponding to the vibration region and the region corresponding to the restricted region are covered with a mask, and the region corresponding to the raised portion is covered with a mask having a width smaller than twice the side etching amount. In this state, the raised portion lower than the vibration region and the constraining region is left on the bottom surface of the concave thin region while the low rigidity region is a concave thin region that opens to the first surface side. The

  In various configurations of the first and second manufacturing methods, preferably, the wiring body installation step includes an insulating layer forming member that forms the insulating layer on the first surface of the elastic plate and the plurality of wiring conductors. A wiring conductor forming member to be formed is provided, and the insulating layer forming member and unnecessary portions of the wiring conductor forming member are etched away to form the insulating layer and the plurality of wiring conductors.

  More preferably, the first and second manufacturing methods may include a step of applying an insulating resin between tip portions of the plurality of wiring conductors and the corresponding piezoelectric elements before the electrical connection step. .

  In this case, the conductive adhesive or the solder in the electrical connection step is in a state in which the insulating resin is interposed between the conductive adhesive or the solder and the first surface of the elastic plate. The tip portions of the plurality of wiring conductors are electrically connected to the top electrode layer of the corresponding piezoelectric element.

FIG. 1 is a longitudinal cross-sectional view of an ultrasonic transducer according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 3 is an enlarged view of a portion III in FIG. FIG. 4 is an enlarged view of a portion IV in FIG. 2 and shows a state in which the sealing member is removed. FIG. 5 is a partially enlarged plan view of the ultrasonic transducer according to the first modification of the first embodiment, showing a state in which some of the constituent members are removed. FIG. 6 is a partially enlarged plan view of the ultrasonic transducer according to the second modification of the first embodiment, and shows a state in which some constituent members are removed. FIG. 7 is a plan view of an ultrasonic transducer according to a third modification of the first embodiment, showing a state in which some components are removed. FIG. 8 is a plan view of an ultrasonic transducer according to a fourth modification of the first embodiment, showing a state in which some constituent members are removed. 9 (a) to 9 (c) are process diagrams of the method of manufacturing the ultrasonic transducer according to the first embodiment. FIG.10 (a)-(c) are process drawings of the said manufacturing method following FIG.9 (c). FIG. 11 is a process diagram of the manufacturing method subsequent to FIG. FIG. 12 is a process diagram of the manufacturing method following FIG. FIG. 13 is an enlarged view of a portion XIII in FIG. FIG. 14 is a process diagram of the manufacturing method subsequent to FIG. FIG. 15 is a process diagram of the manufacturing method following FIG. FIG. 16 is a process diagram of the manufacturing method following FIG. FIG. 17 is a longitudinal sectional view of an ultrasonic transducer according to a fifth modification of the first embodiment. FIG. 18 is a longitudinal sectional view of an ultrasonic transducer according to a sixth modified example of the first embodiment. FIG. 19 is a longitudinal sectional view of a modified configuration relating to the sealing member of the first embodiment. FIG. 20 is a longitudinal sectional view of a modified configuration relating to the sealing member of the fifth modified example of the first embodiment. FIG. 21 is a longitudinal sectional view of a modified configuration relating to the sealing member of the sixth modified example of the first embodiment. FIG. 22 is a longitudinal sectional view of an ultrasonic transducer according to Embodiment 2 of the present invention. FIG. 23 is a cross-sectional view taken along line XXIII-XXIII in FIG. FIG. 24 is an enlarged view of a portion XXIV in FIG. FIG. 25 is a process drawing of the method of manufacturing an ultrasonic transducer according to the second embodiment, and shows the process following FIG. 12. FIG. 26 is a process diagram of the manufacturing method continued from FIG. 25. FIG. 27 is a process diagram of the manufacturing method continued from FIG. FIG. 28 is a process diagram of the manufacturing method continued from FIG. FIG. 29 is a process diagram of the manufacturing method continued from FIG. FIG. 30 is a process diagram of the method of manufacturing an ultrasonic transducer according to the second embodiment, and is a plan view of a state in which a mass plate is fixed. 31 is a longitudinal sectional view taken along the line XXXI-XXXI in FIG. FIG. 32 is an enlarged view of a portion XXXII in FIG. FIG. 33 is an enlarged view corresponding to FIG. 32, and shows a state in which the inter-restraint area bridge and the restraining area / base area bridge in the mass plate are cut. FIG. 34 is a longitudinal cross-sectional view of an ultrasonic transducer according to a first modification of the second embodiment. FIG. 35 is a longitudinal cross-sectional view of an ultrasonic transducer according to a second modified example of the second embodiment. FIG. 36 is a longitudinal sectional view of an ultrasonic transducer according to a third modification of the second embodiment. FIG. 37 is a longitudinal cross-sectional view of an ultrasonic transducer according to a third modification of the second embodiment. FIG. 38 is a partial longitudinal sectional view of an ultrasonic transducer according to Embodiment 3 of the present invention. FIG. 39 is a cross-sectional plan view of the ultrasonic transducer taken along the line XXXIX-XXXIX in FIG. 40 (a) to 40 (c) are process drawings of the method of manufacturing an ultrasonic transducer according to the third embodiment.

Embodiment 1
Hereinafter, an embodiment of an ultrasonic transducer according to the present invention will be described with reference to the attached drawings.
FIG. 1 shows a longitudinal sectional view of an ultrasonic transducer 1A according to the present embodiment.
2 and 3 show a cross-sectional view and an enlarged view of a portion III, respectively, along the line II-II in FIG.

  The ultrasonic transducer 1A according to the present embodiment is suitably used as a phased array sensor used for detection of the shape of an object, detection of an object over a wide range, and the like.

  Specifically, as shown in FIG. 1 to FIG. 3, the ultrasonic transducer 1A includes an elastic plate 10 having a first surface 10a and a second surface 10b facing the one side and the other side in the plate thickness direction, It is provided on the first surface 10 a of the elastic plate 10 so as to cover the plurality of piezoelectric elements 30 fixed in parallel to the first surface 10 a of the elastic plate 10 in the plate surface direction and the plurality of piezoelectric elements 30. And a sealing member 40.

The elastic plate 10 is made of various materials such as stainless steel, Ni-Fe alloy, aluminum alloy, titanium alloy or other metal plate, carbon fiber reinforced plastic and ceramics as long as it has elasticity capable of vibrating in the thickness direction. obtain.
The elastic plate 10 has, for example, a thickness of 0.03 mm to 0.1 mm.
In the present embodiment, the elastic plate 10 is formed of a conductive metal plate.

The piezoelectric element 30 has a piezoelectric body made of PZT (lead zirconate titanate), and a pair of upper and lower electrode layers disposed on both sides in the thickness direction of the piezoelectric body.
The piezoelectric body has a thickness of 0.05 mm to 0.3 mm, for example, and the upper electrode layer and the lower electrode layer are made of Ag or Au having a thickness of 0.05 μm to several μm, for example.

  The plurality of piezoelectric elements 30 are fixed in parallel to the first surface 10 a in a state in which the lower electrode layer is opposed to the first surface 10 a of the elastic plate 10.

  Specifically, as shown in FIGS. 1 to 3, the elastic plate 10 encloses a plurality of vibration areas 12 to which the plurality of piezoelectric elements 30 are respectively attached, and a plurality of the vibration areas 12 in plan view. A plurality of low rigidity regions 26, a plurality of restraint regions 14 respectively surrounding the plurality of low rigidity regions 26 in plan view, a single restraint region 14, and an outward located radially outward from the single restraint region 14 A boundary area 16 is provided to partition the area.

  As shown in FIG. 2, m (five in the illustrated embodiment) of the ultrasonic transducers 1A according to the present embodiment are arranged along the first plate surface direction D1 of the elastic plate 10. In the second plate surface direction D2 orthogonal to the first plate surface direction D1, n rows (three rows in the illustrated embodiment), and m of the restricted region groups 14A formed by the restraint regions 14 are provided It has x n (in the illustrated embodiment, 5 x 3 = 15) the restraint regions 14.

Similarly, m × n of the plurality of low-rigidity regions 26 each surrounded by the plurality of constraining regions 14 are provided, and the plurality of vibration regions 12 each surrounded by the plurality of low-rigidity regions 26 are similarly m × n. n pieces are provided.
The piezoelectric element 30 is attached to each of the m × n vibration regions 12.

  In the present embodiment, as shown in FIG. 2, the elastic plate 10 has a base region 11 that surrounds the entire plurality of restraint regions 14 in a plan view.

  In this case, among the plurality of constraining areas 14, the constraining areas 14 located at the outermost periphery, for example, the constraining areas 14 (1-1) positioned in the first row from the top and the first column from the left in FIG. , A constraint area 14 adjacent to the right (constraint area 14 (1-2) located in the first row from the top and the second column from the left), a constraint area 14 (the second row from the top) The constraint area 14 (2-1)) positioned in the first row from the left and the base area 11 adjacent to the upper side and the left side are the outer areas opposed to each other with the boundary area 16 interposed therebetween.

  And, for the constraint area 14 (2-2) located in the second row from the top and the second column from the left in FIG. Adjacent restraint region 14 (the first row from the top and the second restraint column 14 (1-2) from the left), and a restraint region 14 adjacent to the right (the second row from the top and the third row from the left) Constraint area 14 (2-3)), Constraint area 14 adjacent to the lower side (the third line from the top (bottom line) and the constraint area 14 (3-2) in the second column from the left), and Adjacent restraint regions 14 (the second row from the top and the first restraint region 14 (2-1) from the left) are the outer regions facing each other across the boundary region 16.

  In the present embodiment, as shown in FIG. 2, the plurality of constrained regions 14 are arranged in a lattice, but it goes without saying that the plurality of vibration regions 12 are limited to such an arrangement. Instead, they may be arranged in a staggered or radial manner.

  In the present embodiment, as described above, the elastic plate 10 is a conductive metal plate, and in the piezoelectric element 30, the lower electrode layer is the elastic plate by the conductive adhesive 38 (see FIG. 3). It is mechanically fixed to the first surface 10 a of the elastic plate 10 in a state of being electrically connected to the first surface 10 a of 10.

FIG. 4 is an enlarged view of a portion IV in FIG. 2 and is an enlarged view of the state where the sealing member 40 is removed.
As shown in FIG. 4, the boundary region 16 divides one constraining region 14 where the boundary region 16 defines the outer peripheral edge and the outer region adjacent to the radially outward direction of the one constraining region 14. It has a slit portion 17 and a bridge portion 18 which maintains the mechanical connection of the one restraint area 14 to the outward area.

The sealing member 40 is, as shown in FIG. 3, a plurality of cylindrical portions 42 respectively surrounding the plurality of vibration regions 12 in a plan view, and the elastic plate at a position where the base end surface includes the boundary region 16. A plurality of cylindrical portions 42 joined to the first surface 10a of 10, a plurality of closed portions 44 respectively closing the openings on the free end side of the plurality of cylindrical portions 42, and a proximal end surface of the cylindrical portion 42 And a filling portion 41 extending into the inside of the slit portion 17.
The sealing member 40 is formed of, for example, a polymer material such as silicone.

  Thus, in the ultrasonic transducer 1A according to the present embodiment, a plurality of vibrations vibrated by the plurality of piezoelectric elements 30 by mounting the plurality of piezoelectric elements 30 on the single elastic plate 10 The slit portion 17 causes the vibration of one vibration region 12 to propagate to an outward region located radially outward of the one vibration region 12 while realizing as close arrangement as possible between the regions 12. It can be effectively prevented or reduced.

  Therefore, ultrasonic waves of low frequency (for example, 30 kHz to 40 kHz) can be emitted from the piezoelectric element 30 and the vibration area 12, and it is effective that the grating lobe phenomenon occurs between the plurality of piezoelectric elements 30. Can be prevented or reduced.

  Furthermore, in the ultrasonic transducer 1A, as described above, the filling portion 41 of the sealing member 40 made of a polymer material is filled in the slit portion 17, whereby one vibration region 12 is obtained. The posture stabilization of the constraining region 14 and hence the operation stabilization of the vibrating region 12 are obtained while obtaining the effect of effectively preventing or reducing the propagation of the vibration to the adjacent vibrating region 12 by the slit portion 17. Can be implemented.

  In the present embodiment, as shown in FIG. 4, the slit portion 17 is positioned on both sides in the second plate surface direction D2 of one piezoelectric element 30 mounted in the vibration area 12 in the one constraining area 14. A pair of first plate surface direction slits 17a extending along the first plate surface direction D1 and both sides of the first plate surface direction D1 of the one piezoelectric element 30 in the second plate surface direction D2 And a pair of second plate surface direction slits 17b extending along the same.

  The pair of first plate surface direction slits 17 a is longer than the first plate surface direction length 30 a of the one piezoelectric element 30, and the pair of second plate surface direction slits 17 b is the second of the one piezoelectric element 30. At four locations defined by the end portions of the first plate surface direction slit 17a and the second plate surface direction slit 17b which are longer than the plate surface length 30b and which are adjacent in the circumferential direction The bridge portion 18 is provided.

  According to such a configuration, it is possible to stably hold the plurality of constraining regions 14 while effectively preventing the propagation of vibration among the plurality of piezoelectric elements 30 arranged in a rectangular shape.

  Further, in the present embodiment, as described above, only a single boundary region 16 exists between adjacent restraint regions 14, and the restraint regions where the slits 17 of the single boundary region 16 are adjacent to each other. The two outer rims of 14 are drawn.

  According to such a configuration, the installation area of the plurality of constraining regions 14 can be reduced as much as possible while effectively preventing the vibration propagation between the plurality of piezoelectric elements 30.

The slit portion 17 and the bridge portion 18 can have various configurations.
FIG. 5 shows a partially enlarged plan view of an ultrasonic transducer 1B according to a first modification including the slit portion 21 and the bridge portion 22 having different configurations.

In the first modification 1B shown in FIG. 5, the slit portion 21 has an arc shape.
The four slit portions 21 surround one restricted area 14, and the bridge portion 22 is provided between two adjacent slit portions 21 in the circumferential direction.

  Further, FIG. 6 shows a partially enlarged plan view of an ultrasonic transducer 1C according to a second modified example provided with the slit portion 23 and the bridge portion 24 having different configurations.

In the second modification 1C shown in FIG. 6, the slit portion 23 is substantially L-shaped in plan view.
The four slit portions 23 surround one restricted area 14.

  Specifically, two L-shaped slits 23 adjacent in the circumferential direction overlap in the circumferential direction with the portion 23a of one slit 23 positioned radially inward of the portion 23b of the other slit 23 The radial gap between the portion 23 a of the one slit 23 and the portion 23 b of the other slit 23 forms the bridge portion 24.

  In the slit portion 17 (21, 23) and the bridge portion 18 (22, 24) of various configurations, preferably, when the circumferential direction length of the boundary region 16 is L, the plurality of slit portions 17 (21 , 23) can be configured to satisfy La ≧ 0.9 × L.

  As described above, in the ultrasonic transducer 1A according to the present embodiment, the low-rigidity region 26 having a lower rigidity than the vibration region 12 and the restraining region 14 is provided around the vibration region 12. It is done.

By providing such a configuration, the vibration characteristic of the vibration area 12 can be enhanced.
Therefore, it is possible to generate low-frequency sound waves while reducing the size of the vibration region 12 and reducing the arrangement pitch of the plurality of vibration regions 12.

  In the present embodiment, as shown in FIGS. 2 and 4, the outer shape of the vibration region 12 and the outer shape of the piezoelectric element 30 are the same, and the first surface 10 a of the elastic plate 10 is the same. A groove 27 is provided in an area along the outer peripheral edge of the vibration area 12, and the low rigidity area 26 is formed by the groove 27.

  According to such a configuration, the groove 27 can be used as an alignment mark when the piezoelectric element 30 is mounted on the vibration region 12 while the low rigidity region 26 is formed by the groove 27.

  FIG. 7 shows a partially enlarged plan view of an ultrasonic transducer 1D according to a third modification in which the low rigidity regions 26 are formed by different structures.

In a third modification 1D shown in FIG. 7, an opening 28 a for dividing the inside and the outside of the vibration area 12 into a region along the outer peripheral edge of the vibration area 12 of the elastic plate 10 and the inside and the outside of the vibration area 12 Are connected alternately in the circumferential direction, and the low rigidity region 26 is formed by the opening 28a and the connecting portion 28b.
Similarly to the groove 27, the opening 28a and the connecting portion 28b can also be used as alignment marks when the piezoelectric element 30 is mounted in the vibration region 12.

In the present embodiment, the vibration region 12 has a circular shape in a plan view, and the piezoelectric element 30 has a circular shape in a plan view having the same shape as that of the vibration region 12. It is not limited to this form.
FIG. 8 is a plan view of an ultrasonic transducer 1E according to a fourth modification including a vibration region 12 and a piezoelectric element 30 that are rectangular in plan view, and the sealing member 40 and the sound absorbing material 50 are omitted. The top view of a state is shown.

  As shown in FIG. 1 and FIG. 3 etc., the ultrasonic transducer 1A according to the present embodiment further includes a sound absorbing material 50 covering the top electrode layer of the piezoelectric element 30.

  Specifically, in the present embodiment, as shown in FIG. 3, the cylindrical portion 42 is provided such that the upper end portion is separated from the first surface 10 a of the elastic plate 10 rather than the upper surface of the piezoelectric element 30. In addition, the closing portion 44 is provided so as to leave a gap between the upper surface electrode layer of the piezoelectric element 30.

  In addition, in the housing space for housing the piezoelectric element 30, which is surrounded by the first surface 10a of the elastic plate 10, the cylindrical portion 42, and the closing portion 44, it is formed of a foamable resin such as foamable silicone. The sound absorbing material 50 is filled.

  By providing the sound absorbing material 50, it is possible to prevent or reduce the leakage of the ultrasonic wave from the vibration area 12 to the rear (the first surface 10a side with respect to the thickness direction of the elastic plate 1). The echo of the ultrasonic wave can be effectively suppressed after the radiation is emitted.

As shown in FIGS. 1 and 3, the ultrasonic transducer 1A according to the present embodiment further has a reinforcing plate 60 fixed to the outer surface of the closed portion 44 of the sealing member 40.
The reinforcing plate 60 is formed of a rigid plate such as stainless steel.

  By providing the reinforcing plate 60, the strength of the ultrasonic transducer 1A can be increased without disturbing the vibration characteristics.

The ultrasonic transducer 1A according to the present embodiment further includes a protective member 70 joined to the second surface 10b of the elastic plate 10 and has an opening 72 that opens the vibration region 12 outward. A member 70 is provided.
The protective member 70 is formed of, for example, silicone having a thickness of about 0.5 mm to 1.5 mm.

  By providing the protective member 70, the elastic plate 10 can be protected without impairing vibration characteristics.

The ultrasonic transducer 1 </ b> A further includes a rigid protective plate 75 joined to the outer surface of the protective member 70.
The protective plate 75 is provided with a through hole 77 at a position corresponding to the opening 72 of the protective member 70.
The protective plate 75 is formed of a metal plate such as stainless steel, Ni-Fe alloy, aluminum alloy, titanium alloy, etc. having a thickness of about 0.1 mm to 0.5 mm.

  By providing the protective plate 75, it is possible to effectively prevent the protective member 70 from vibrating unintentionally while preventing or reducing damage to the protective member 70 effectively.

  Furthermore, as shown in FIGS. 1 to 4, the ultrasonic transducer 1 </ b> A according to the present embodiment includes a wiring body 80 for applying a voltage to the upper surface electrode layer of the piezoelectric element 30.

The wiring body 80 includes an insulating layer 82 fixed on the first surface 10 a of the elastic plate 10 and a conductor layer 84 laminated on the insulating layer 82.
The insulating layer 82 is formed of, for example, a polyimide having a thickness of about 18 μm to 25 μm.
The conductor layer 84 is formed of, for example, Cu / Au with a thickness of about 12 μm to 18 μm.

  The conductor layer 84 has a plurality of wiring conductors 85 electrically connected to the upper surface electrode layers of the plurality of piezoelectric elements 30.

  As shown in FIG. 3, the plurality of wiring conductors 85 are electrically connected to the top electrode layer of the piezoelectric element 30 corresponding to the tip through the conductive adhesive or the solder 87, and the base end Form a pad 86 (see FIG. 2) for connection to the outside.

  In the present embodiment, as shown in FIG. 3, the conductive adhesive or the solder 87 and the elastic plate 10 that electrically connect the tip end portion of the wiring conductor 85 and the upper electrode layer of the piezoelectric element 30. An insulating resin 88 is interposed between the first surface 10a and the first surface 10a, thereby effectively preventing the wiring conductor 85 and the upper electrode layer from shorting to the elastic plate 10.

As described above, the lower surface electrode layers of the plurality of piezoelectric elements 30 are electrically connected to the conductive elastic plate 10 via the conductive adhesive 38.
The elastic plate 10 is provided with a lower surface electrode layer pad 89 (see FIG. 2) in a state of being electrically connected to the elastic plate 10.

  The wiring body 80 may be provided with an insulating cover layer (not shown) surrounding the conductor layer 84 in order to effectively prevent the conductor layer 84 from coming into contact with the outside.

Next, an example of a method of manufacturing the ultrasonic transducer 1A will be described.
The manufacturing method includes a step of preparing a conductive elastic plate forming body 110 for forming the elastic plate 10 and a wiring body installation step for providing the wiring body 80.

  In the manufacturing method, the wiring body installation step includes the insulating layer forming member 182 forming the insulating layer 82 on the first surface on one side in the thickness direction of the elastic plate forming body 110 and the plurality of wiring conductors 85. A step of providing a wiring body forming member 180 including a wiring conductor forming member 185 to be formed (FIG. 9A), and unnecessary portions of the wiring body forming body 180 are removed by etching to remove the insulating layer 82 and the plurality of wiring conductors. Forming the wiring body 80 including 85 (FIGS. 9B and 9C).

  In the present embodiment, in the step of forming the wiring body 80, first, unnecessary portions of the wiring conductor forming member 185 are etched away to form the plurality of wiring conductors 85 (FIG. 9B). Thereafter, unnecessary portions of the insulating layer forming member 182 are removed by etching to form the insulating layer 82 (FIG. 9C).

  The manufacturing method further includes an elastic plate etching step (FIGS. 10A and 10B) of etching the elastic plate forming body 110 to form the slit portion 17.

  In the present embodiment, in the elastic plate etching step, in addition to the formation of the slit portion 17, a groove 27 to a region along the outer peripheral edge of the vibration region 12 in the first surface 10 a of the elastic plate 10. (See FIG. 10 (a)).

  In the present embodiment, first, the groove 27 is formed by half etching, and then the slit portion 17 is formed. However, the formation order of the groove 27 and the slit portion 17 does not matter.

  Further, when the low-rigidity region 26 is caused to appear by the plurality of openings 28a as in the modification 1D, the elastic plate etching step is performed in place of the formation of the groove 27 instead of the vibration region 12. The plurality of openings 28a are formed along the outer peripheral edge of the opening 28a between the openings 28a adjacent to each other in the circumferential direction.

  The manufacturing method further includes a piezoelectric element mounting step of adhering lower surface electrode layers of the plurality of piezoelectric elements 30 to the first surface 10 a of the plurality of vibration areas 12 with a conductive adhesive 38.

  Specifically, the piezoelectric element mounting step includes a step (FIG. 10 (c)) of applying a conductive adhesive 38 to the first surface 10a of the plurality of vibration regions 12, and a top of the conductive adhesive 38. And the step of curing the conductive adhesive 38 (FIG. 11).

  10 (a) to 10 (c), reference numeral 39 denotes gold plating provided on the first surface 10a of the vibration area 12 before the application of the conductive adhesive 38, and the conductive adhesive 38 and the vibration are illustrated. This is for improving the reliability of the electrical connection of the region 12 with the first surface 10a.

  In addition, the said wiring body installation process, the said elastic board etching process, and the said piezoelectric element mounting process can be implemented in arbitrary order.

  The manufacturing method further includes an electrical connection step of electrically connecting the tip portions of the plurality of wiring conductors 85 to the corresponding upper surface electrode layers of the piezoelectric elements 30 with a conductive adhesive or solder 87 (FIGS. 12 and 13). )have.

  Here, in the present embodiment, in order to effectively prevent the upper surface electrode layer and the lower surface electrode layer from shorting when the conductive adhesive 87 contacts the elastic plate 10, the manufacturing method Before the electrical connection step, the step of applying an insulating adhesive 88 between the tip end portions of the plurality of wiring conductors 85 and the corresponding piezoelectric elements 30 (FIG. 13).

  In this case, the conductive adhesive or the solder 87 in the electrical connection step has the insulating adhesive 88 interposed between the conductive adhesive or the solder 87 and the first surface 10 a of the elastic plate 10. It is applied so as to electrically connect the top end portions of the plurality of wiring conductors 85 to the top electrode layer of the corresponding piezoelectric element 30 in the inserted state.

  The manufacturing method further includes a protective member installation step of installing the protective member 70 and a protective plate installation step (FIG. 14) of installing the protective plate 75.

  The protective member 70 is fixed to the second surface 10 b of the elastic plate 10 so as to close the second surface side of the slit portion 17 while opening the vibration region 12 outward through the opening 72. Be done.

  In the present embodiment, the protective member installation step and the protective plate installation step include a process of preparing the protective member 70 and a protective pre-assembly by previously bonding the protective plate 75 to the outer surface of the protective plate 70. And a process of adhering the protective pre-assembly to the second surface 10 b of the elastic plate 10.

  Needless to say, the protective member installation step and the protective plate installation step are performed by bonding the protective member 70 to the second surface 10b of the elastic plate 10 and bonding the protective plate 75 to the outer surface of the protective member 70. It is also possible to deform so as to have a process of

Next, the manufacturing method includes a sealing member installation step of installing the sealing member 40.
In the present embodiment, in the sealing member installation step, the installation step of the first sealing member 40 a integrally forming the filling portion 41 and the cylindrical portion 42 and the closing portion 44 are formed. And 2) installing the sealing member 40b.

  In the present embodiment, as shown in FIG. 15, in the first sealing member installation step, the area where the cylindrical portion 42 is to be provided (cylindrical portion installation area) is exposed in the state where the upper portion is opened. A process for installing the cylindrical part mold 49 to be applied, and a first polymer material such as silicone is applied into the cylindrical part mold 49 from the first surface 10a side of the elastic plate 10 and cured. And processing.

  As the first polymer material, for example, a liquid silicone having a relatively low viscosity of about 400 mPa · s to about 1000 mPa · s before curing can be suitably used.

  As described above, by using a liquid silicone with low viscosity in the state before curing as the first polymer material, generation of a gap is effectively prevented in the inside of the slit portion 17 and the cylindrical portion installation region. Can be filled with the first polymer material while being reduced.

At this time, the opening on the lower side (the second surface side of the elastic plate) of the slit portion 17 is closed by the protective member 70.
Therefore, even if the viscosity before curing of the first polymer material injected into the slit portion 17 is low, the first polymer material is on the lower side (second surface side) of the slit portion 17. The outflow from the opening is effectively prevented.

  When the first polymer material is a thermosetting type, heating at a curing temperature (for example, 100 ° C. to 150 ° C.) is performed after the application of the first polymer material to the tubular portion installation region. The curing process can be carried out.

  In the present embodiment, the manufacturing method includes a sound absorbing material installing step of installing the sound absorbing material 50 after the first sealing member installing step and before the second sealing member installing step. Have (Figure 16).

  At this time, the region where the sound absorbing material 50 is to be installed is surrounded by the cylindrical portion 42. Therefore, in the sound absorbing material installing step, the sound absorbing material 55 is formed in the space surrounded by the cylindrical portion 42. A foamable resin such as foamable silicone is applied and cured, whereby the sound absorbing material can be stably installed.

As described above, in the present embodiment, the sound absorbing material installation process is configured to be performed after the first sealing member installation process, but the sound absorbing material installation process is performed as the first sealing member installation. It is also possible to configure it to run before the process.
In this case, the cylindrical member form 49 is omitted.

  In the present embodiment, the second sealing member installation step is performed after the first sealing member installation step and the sound absorbing material installation step.

  In the second sealing member installation step, after the cylindrical portion 42 and the sound absorbing material 50 are installed, a second polymer material such as silicone is applied to the upper surface of the cylindrical portion 42 and the sound absorbing material 50 Configured to cure (see FIGS. 1 and 3).

  In this case, the second polymer material is a liquid silicone having a viscosity before curing higher than that of the first polymer material, for example, a high viscosity liquid having a viscosity before curing of about 1000 mPa · s to 100,000 mPa · s. Silicone can be used.

  When the second polymer material is a thermosetting type, a curing temperature (for example, 100 ° C. to 150 ° C.) is applied after the second polymer material is applied to the upper surface of the cylindrical portion 42 and the sound absorbing material 50. The curing treatment can be carried out by performing the heating in the above.

  The manufacturing method includes a reinforcing plate installation step of bonding the reinforcing plate 60 to the outer surface of the closed portion 44 after the closed portion 44 (the second sealing member 40b) is installed (FIG. 1). And Figure 3).

Instead of this, the installation of the second sealing member 40 b and the installation of the reinforcing plate 60 can be simultaneously performed.
That is, the second sealing member 40b forming the closed portion 44 is separately prepared, and the reinforcing plate 60 is adhered to the outer surface of the second sealing member 40b to form a second sealing member with a reinforcing plate. The second sealing member 40b and the reinforcing plate 60 can be installed by forming in advance and bonding the second sealing member with the reinforcing plate to the upper surfaces of the cylindrical portion 42 and the sound absorbing member 50. It is.

  Although the ultrasonic transducer 1A according to the present embodiment has a flat protective plate 75 (see FIG. 1 and the like), a protective container 175 may be provided instead of the protective plate 75.

  FIG. 17 is a longitudinal sectional view of an ultrasonic transducer 1F according to a fifth modification including the protective container 175.

  The protective container 175 is fixed to the outer surface of the protective member 70, and an end wall portion 176 provided with a through hole 177 at a position corresponding to the opening 72 of the protective member 70, the protective member 70, and the elastic member The peripheral wall 178 extends from the end wall 176 so as to surround the side walls of the plate 10 and the sealing member 44.

  In the modification 1F, the reinforcing plate 60 is fixed to the peripheral wall portion 178 so as to close the free end side opening of the peripheral wall portion 178.

The protective container 175 also acts as a mold when applying the cylindrical portion 42 and the closed portion 44.
The protective container 175 is preferably formed of, for example, a resin material such as an epoxy resin, or a metal such as stainless steel, a Ni—Fe alloy, an aluminum alloy, or a titanium alloy.

  FIG. 18 is a longitudinal sectional view of an ultrasonic transducer 1G according to a sixth modification including another protective container 175 '.

  In Modification 1F shown in FIG. 17, the peripheral wall portion 178 of the protective container 175 is configured to be in contact with the side surfaces of the protective member 70, the elastic plate 10, and the cylindrical portion 42.

Instead of this, a protective container 175 ′ of the modified example 1G shown in FIG. 18 has a peripheral wall 178 ′ instead of the peripheral wall 178 in comparison with the protective container 175.
The peripheral wall portion 178 ′ is configured such that a gap exists between the protective member 70, the elastic plate 10, and the side surface of the cylindrical portion 42.
The gap is filled with the second polymeric material forming the closed portion 44.

  In Embodiment 1A, the fifth modification 1F, and the sixth modification 1G, the sound absorbing material 50 is provided on the upper surface of the piezoelectric element 30, and the sealing member 40 is filled. Although it has the 1st sealing member 40a which forms the part 41 and the said cylindrical part 42, and the 2nd sealing member 40b which forms the said closed part 44, this invention is limited to such a form is not.

  For example, it is possible to provide a single sealing member 40 'instead of the sound absorbing member 50, the first sealing member 40a and the second sealing member 40b.

19, 20 and 21 show ultrasonic transducers 1A, 1F and 1G according to the present embodiment (FIG. 1), the fifth modification (FIG. 17) and the sixth modification (FIG. 18), respectively. A single seal integrally having the filling portion 41, the cylindrical portion 42 and the closing portion 44 in place of the sound absorbing material 50, the first sealing member 40a and the second sealing member 40b The longitudinal cross-sectional view of ultrasonic transducer 1A ', 1F', 1 G 'provided with member 40' is shown.
The single sealing member 40 may be formed of the first polymer material of the same material as the first sealing member 40a.

Embodiment 2
Hereinafter, other embodiments of the ultrasonic transducer according to the present invention will be described with reference to the attached drawings.
FIG. 22 shows a longitudinal sectional view of an ultrasonic transducer 2A according to the present embodiment.
Further, FIGS. 23 and 24 respectively show a cross-sectional view along line XXIII-XXIII in FIG. 22 and an enlarged view of a portion XXIV.
In the figure, the same members as those in the first embodiment are denoted by the same reference numerals, and the detailed description thereof is appropriately omitted.

  As shown in FIGS. 22 to 24, the ultrasonic transducer 2A according to the present embodiment mainly includes a mass member 210 fixed to the first surface 10a of the elastic plate 10, and Instead of the reinforcing plate 60 and the protective plate 75, the ultrasonic transducer 1A according to the first embodiment is provided with a reinforcing plate 260 and a protective plate 275 connected to each other via the spacer 250. And is different.

  The mass member 210 is fixed to the first surface 10 a of the elastic plate 10 so as to open the first surfaces of the vibration region 12, the low rigidity region 26, and the boundary region 16.

  In the present embodiment, as shown in FIGS. 22 to 24, the mass member 210 is fixed to the first surface of the constraining region 14 so as to surround the vibration region 12 and the low-rigidity region 26 in plan view. The vibration region mass member 210a includes a base region mass member 210b fixed to the base region 11 so as to surround the whole of the plurality of restraint regions 14 in a plan view.

The mass member 210 is a metal such as stainless steel, Ni-Fe alloy or the like with a thickness of about 0.1 mm to 1.0 mm.
The mass member 210 is fixed to a desired position of the elastic plate by spot welding with an adhesive or a laser.

  By providing the mass member 210, it is possible to effectively or reduce the vibration of the restraint area 14 due to the vibration propagating from the vibration area 12.

  As shown in FIG. 24, a portion of the base end surface of the restraining region mass member 210a located on the wiring body 80 is provided with a recess or notch 211 that prevents interference with the wiring body 80. It is done.

  By providing such a configuration, it is possible to effectively prevent contact between the restraint region mass member 210 and the wiring body 80 while providing the restraint region mass member 210 a over the entire circumference of the vibration region 12. Can.

  As shown in FIGS. 22 and 24, in the present embodiment, the mass member 210 is provided such that the upper end portion is separated from the first surface 10 a of the elastic plate 10 rather than the upper surface of the piezoelectric element 30. It is done.

  In the present embodiment, the first sealing member 40 a that integrally forms the filling portion 41 and the cylindrical portion 42 is a restraint region fixed to one restraint region 14 that surrounds one low-rigidity region 26. Mass member 210a and a mass fixed to an outer area (an adjacent other restricted area 14 or an adjacent adjacent base area 11) opposite to the one restricted area 14 across the boundary area 16 A space sandwiched between the members 210 (the restraint region mass member 210a or the base region mass member 210b) is filled, and the upper end portion is located at the same position as the mass member 210.

  Further, the sound absorbing material 50 uses the mass region member 210a for restraint area fixed to the restraint region 14 surrounding the vibration region 12 to which the corresponding piezoelectric element 30 is fixed as a mold, and the piezoelectric element in the mass member 210a 30 so that the upper end portion is in the same position as the mass member 210a.

  As shown in FIG. 22, the protective plate 275 is overlapped with the protective member 70 in a plan view and has a central portion 276 provided with the through hole 77, and an extension extending outward from the central portion 276 in the plate surface direction. The central portion 276 is fixed to the outer surface of the protective member 70 in a state where the through hole 77 and the opening 72 are aligned.

  The reinforcing plate 260 has a central portion 262 that overlaps the elastic plate 10 in a plan view, and an extending portion 264 that extends outward from the central portion 262 in the plate surface direction.

The extending portion 264 of the reinforcing plate 260 and the extending portion 278 of the protection plate 275 are connected to each other via a spacer 250 having a predetermined length.
The spacer 250 can be made of metal such as stainless steel, for example.
Here, the predetermined length of the spacer 250 is set according to the thickness of the ultrasonic transducer 2A.

  In the present embodiment, as shown in FIG. 22, the spacer 250 is a hollow cylindrical body, and the reinforcing plate 260 is extended through a screw member 255 inserted into the hollow portion of the spacer 250. The recess 264 and the extension 278 of the protection plate 275 are connected.

  Alternatively, the spacer 250 may be bonded to the extension 264 of the reinforcing plate 260 and the extension 278 of the guard plate 275.

  Thus, by connecting the reinforcing plate 260 and the protective plate 275 via the spacer 250, the strength of the ultrasonic transducer 2A can be improved.

  As a matter of course, the configuration in which the reinforcing plate 260 and the protective plate 275 are connected via the spacer 250 can also be applied to the ultrasonic transducer 1A according to the first embodiment.

Next, an example of a method of manufacturing the ultrasonic transducer 2A will be described.
The manufacturing method has the same steps as the manufacturing method in the first embodiment up to the electrical connection step (FIGS. 12 and 13).

  The manufacturing method includes a mass member installation step of fixing the mass member 210 to predetermined positions of the restraining region 14 and the base region 11 after the electrical connection step (FIG. 25).

  In the present embodiment, as shown in FIG. 23, the mass member installation step includes a process of fixing the restraint region mass members 210a to the plurality of restraint regions 14, respectively, and the entire restraint regions 14 as a whole. And a process of fixing the base region mass member 210b at a predetermined position of the base region 11 surrounding the above.

  As described above, the restraint region mass member 210a and the base region mass member 210b that constitute the mass member 210 are made of a metal such as stainless steel or a Ni-Fe alloy having a thickness of about 0.1 mm to 1.0 mm. It is fixed to each predetermined position by spot welding with an adhesive or laser.

Next, the manufacturing method has a sound absorbing material installation step of installing the sound absorbing material 50 (FIG. 26).
At this time, the area where the sound absorbing material 50 is to be installed is surrounded by the restraint area mass member 210a, and therefore, the foam is formed to cover the piezoelectric element 30 in the space surrounded by the restraint area mass member 210a. The sound absorbing material 50 can be stably installed by being filled with a foamable resin such as silicone.

  The manufacturing method further includes a protective member installation step of installing the protective member 70 and a protective plate installation step (FIG. 27) of installing the protective plate 275.

  In the present embodiment, the protective member installation step and the protective plate installation step include a process of preparing the protective member 70 and a protective pre-assembly in which the protective plate 275 is bonded in advance to the outer surface of the protective member 70. And a process of adhering the protective pre-assembly to the second surface 10 b of the elastic plate 10.

  Needless to say, the protective member installation step and the protective plate installation step are performed by bonding the protective member 70 to the second surface 10b of the elastic plate 10 and bonding the protective plate 275 to the outer surface of the protective member 70. It is also possible to deform so as to have a process of

The protective member installation step and the protective plate installation step may be performed after the mass member installation step and the sound absorbing material installation step, or may be performed before the mass member installation step and the sound absorption material installation step. You can also.
Alternatively, the protective member installation step and the protective plate installation step may be performed between the mass member installation step and the sound absorbing material installation step.

  The manufacturing method includes a sealing member installation step of installing the sealing member 40 after at least the mass member installation step and the protection member installation step are completed.

  In the sealing member installation step, the installation step of the first sealing member 40a integrally forming the filling portion 41 and the cylindrical portion 42, and the installation of the second sealing member 40b forming the closed portion 44 And a process.

  The first sealing member installation step is configured to apply and cure the first polymer material in a region where the cylindrical portion 42 is to be provided, using the mass members 210a and 210b as molds. (Figure 28).

  Specifically, the first sealing member installation step is performed between the adjacent constraining area mass member 210a and the other constraining area mass member 210a, and between the constraining area mass part 210a and the base region. The first sealing member 40a that integrally forms the filling portion 41 and the tubular portion 42 is installed between the mass members 210b by applying and curing the first polymer material. ing.

  The manufacturing method includes a step of installing the reinforcing plate 260 before the second sealing member installation step and after at least the protection plate 275 is installed (FIG. 29).

  The reinforcing plate installation step is configured to install the reinforcing plate 260 by connecting the extending portion 278 of the protective plate 275 and the extending portion 264 of the reinforcing plate 260 via the spacer 250. There is.

  The said manufacturing method performs a said 2nd sealing member installation process after the said reinforcement board installation process (FIG. 22).

In the present embodiment, as shown in FIG. 22, FIG. 24 and FIG. 29, the reinforcing plate 260 is provided with a through hole 263 communicating the inner surface and the outer surface, and the second sealing member The installation step is configured to inject the second polymer material from the outside through the through hole 263 of the reinforcing plate 260.
According to such a configuration, the thickness of the closed portion 44 can be formed with good controllability.

  As described above, in the present embodiment, the mass member installation step includes a process of fixing the restraint region mass member 210a to each of the plurality of restraint regions 14 and the base region for the base region 11 at a predetermined position. And a process of fixing the mass member 210b.

  As described above, in the present embodiment, the first sealing member installation step is performed after the sound absorption member installation step, but instead of this, the first sound absorption member installation step is performed. It is also possible to carry out the process after the first sealing member installation process.

  That is, after the mass members 210a and 210b are installed and the protection member 70 is installed, the first sealing member 40a is installed before the sound absorbing material 50, and then the sound absorbing material 50 is installed. It is also possible.

  Here, the plurality of restraint area mass members 210a and the base area mass members 210b are separate from each other, and accordingly, the plurality of restraint area mass members 210a and the base area mass members 210b. For each of the above, alignment processing and fixing processing are required.

  In this regard, if the mass plate 200 in which the plurality of mass region members 210a and the base region mass members 210b are integrally connected via the bridges 215 and 216 described below, the mass member installation step is performed. Simplification and speeding up can be achieved.

FIG. 30 shows a plan view of a pre-assembly in which the mass plate 200 is fixed to the elastic plate 10 after the electrical connection step.
31 and 32 show a cross-sectional view along the line XXXI-XXXI in FIG. 30 and an enlarged view of the XXXII part in FIG. 31, respectively.

  As shown in FIGS. 30 to 32, the mass plate 200 includes a plurality of restraint area mass members 210a, a base area mass member 210b, an adjacent restraint area mass member 210a, and other restraint areas. A constrained-area bridge 215 that connects the upper ends of the area mass members 210a, and a constrained area / base-area bridge 216 that connects the upper ends of the adjacent restricted area mass members 210a and base area mass members 210b. have.

  The restraint region bridge 215 and the restraint region / base region bridge 216 are thinner than the restraint region mass member 210a and the base region mass member 210b so as to be easily broken.

  The mass plate 200 is, for example, a plate-like metal block such as stainless steel having a thickness (for example, 0.2 mm to 1.0 mm) according to the height of the restraint area mass member 210a and the base area mass member 210b. Can be efficiently formed by half etching a region corresponding to the inter-restraint region bridge 215 and the restraining region / base region bridge 216 from the surface on one side of the metal block.

  The restraint inter-region bridge 215 and the restraint / base region bridge 216 may have a thickness of, for example, about 0.03 mm to 0.07 mm.

  In the mass member installation step using the mass plate 200, a process of fixing the mass plate 200 to the first surface 10a of the elastic plate 10 at a predetermined position, the inter-restraint area bridge 215, and the restraining area / base area The bridge 216 is cut to separate the plurality of restraint region mass members 210a and the base region mass member 210b.

  FIG. 33 shows a longitudinal cross-sectional view corresponding to FIG. 32 in a state where the inter-restraint area bridge 215 and the restraining area / base area bridge 216 are cut.

  The cutting between the restraint region bridge 215 and the restraint region / base region bridge 216 can be performed by, for example, laser light irradiation.

  According to the mass member installation process using the mass plate 200, when installing the mass members 210a and 210b, the alignment process and the fixing process may be performed only once, and the installation of the mass members 210a and 210b may be simplified and performed at high speed. Can be implemented.

Various modifications can be made to the ultrasonic transducer 2A according to the present embodiment.
In FIG. 34, compared to the ultrasonic transducer 2A according to the present embodiment, a modification in which the protective container 175 is replaced with the protective plate 275, and a reinforcing plate 60 'is replaced with the reinforcing plate 260 instead of the protective plate The longitudinal cross-sectional view of ultrasonic transducer 2B concerning an example is shown.

  The reinforcing plate 60 'has the same configuration as the reinforcing plate 60 except that a through hole 63 communicating the inner surface and the outer surface is provided.

  Further, FIG. 35 shows a longitudinal cross-sectional view of an ultrasonic transducer 2C according to a modification including the other protection container 175 'instead of the protection container 175, as compared to the modification 2B.

  In addition, in the structure provided with the said protection container 175 or the said protection container 175 ', the said sealing member 40' which has the said filling part 41, the said cylindrical part 42, and the said closing part 44 integrally can be provided. .

FIG. 36 shows a longitudinal sectional view of a modification 2C ′ including the sealing member 40 ′ integrally including the filling portion 41, the cylindrical portion 42, and the closing portion 44 in the modification 2C.
The sealing member 40 ′ may be used in the protective container 175 ′ even if the first polymer material having a low viscosity in the state before curing is used in consideration of the filling of the filling portion 41 in the slit portion 17. The presence can prevent the first polymeric material from flowing out before curing.

  Further, in FIG. 37, as compared with the ultrasonic transducer 2A according to the present embodiment, the protection plate 275 is provided instead of the protection plate 275 and the reinforcement plate 260 is omitted. The longitudinal cross-sectional view of sound wave transducer 2D is shown.

Third Embodiment
Hereinafter, still another embodiment of the ultrasonic transducer according to the present invention will be described with reference to the attached drawings.
FIG. 38 shows a partial longitudinal sectional view of an ultrasonic transducer 3A according to the present embodiment.
Further, FIG. 39 shows a cross-sectional plan view of the ultrasonic transducer 3A along the line XXXIX-XXXIX in FIG.
In the figure, the same members as those in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

  The ultrasonic transducer 3A according to the present embodiment mainly includes the elastic plate 310 and the plurality of piezoelectric elements 330 instead of the elastic plate 10 and the plurality of piezoelectric elements 30 in the embodiment. This differs from the ultrasonic transducer 1A according to 1.

  The elastic plate 310 has a first surface 310a and a second surface 310b respectively facing one side and the other side in the thickness direction, and is formed of a conductive metal plate that can vibrate in the thickness direction.

  As shown in FIGS. 38 and 39, the elastic plates 310 are provided in parallel in the plate surface direction, and a plurality of vibration regions 312 to which the plurality of piezoelectric elements 330 are respectively attached, and the plurality of the plurality of A plurality of low-rigid regions 326 that respectively surround the vibration region 312, a constraining region 314 that respectively surrounds the plurality of low-rigid regions 326 in plan view, and one constraining region 314 and one constraining region 314 that is radially outward. And a boundary region 316 that divides the outer region located.

Similar to the elastic plate 10, the elastic plate 310 has a base region 311 that surrounds the entire plurality of constraining regions 314.
Therefore, for one constrained region 314, the other constrained region 314 and the adjacent base region 311 are the outer regions.

  The boundary region 316 includes the slit portion 17 and the bridge portion 18 in the same manner as the boundary region 16.

  The low rigidity region 326 is a concave thin wall region in which the first surface is closer to the second surface than the first surface of the vibration region 312 and the restraint region 314 and opens on the first surface side.

  That is, the second surface 310 b of the elastic plate 310 is flush with the vibration region 312, the low rigidity region 326, and the restraining region 314, while the first surface 310 a is the low rigidity region 326. Are recessed in the

The piezoelectric element 330 has an outer diameter larger than the vibration area 312 and smaller than the low rigidity area 326.
That is, the piezoelectric element 330 includes a central portion 331 that overlaps with the vibration region 312 in a plan view, and an extending portion that extends radially outward from the central portion 331 and ends in the low-rigidity region 326 in a plan view. And 333.

  As shown in FIG. 38, the lower surface electrode layer in the central portion 331 is fixed to the first surface of the vibration region 312 with an insulating adhesive 340, and the lower surface electrode layer in the extending portion is a conductive adhesive 345. Are electrically and mechanically connected to the first surface of the low rigidity region 326.

  Note that the wiring conductor 85 corresponding to the upper electrode layer of the piezoelectric element 330 is made of a conductive adhesive or solder 87, as in the first embodiment, and the conductive adhesive or solder. An insulating adhesive 88 is interposed between the first surface 310 a of the elastic plate 310 and the conductive adhesive 345.

  In the present embodiment, as shown in FIG. 39, the vibration area 312 has a circular shape in a plan view, the piezoelectric element 330 has a rectangular shape in a plan view, and the low rigidity area 326 has a rectangular shape in a plan view. Of course, the present invention is not limited to such a shape.

  That is, as long as the outer diameter of the piezoelectric element 330 is larger than the outer diameter of the vibration area 312 and smaller than the outer diameter of the low-rigidity area 326, the vibration area 312, the piezoelectric element 330, and the low diameter are reduced. Various shapes are possible, such as making all rigid regions 326 circular in plan view.

Preferably, the low-rigidity region 326 has the same outer shape as the piezoelectric element 330 and an outer diameter slightly larger than the outer diameter of the piezoelectric element 330.
According to such a configuration, the outer peripheral edge of the low-rigidity region 326 can be used as an alignment mark when the piezoelectric element 330 is mounted on the vibration region 312.

  As described above, in the present embodiment, mechanical stability between the vibration area 312 and the central portion 331 of the piezoelectric element 330 is performed by the insulating adhesive 340 while the support stabilization of the piezoelectric element 330 is achieved. The low-rigidity region 326 and the lower electrode layer of the extending portion 333 of the piezoelectric element 330 are connected by a conductive adhesive 345 to electrically connect the lower electrode layer of the piezoelectric element 330 and the elastic plate 310. You are getting

  Furthermore, in the ultrasonic transducer 3A, as shown in FIG. 38, the bottom surface (first surface) of the thin region forming the low rigidity region 326 is lower than the first surface 310a of the vibration region 312. A raised portion 328 is provided which co-operates with the inner surface of the thinned region to form an adhesive retention region.

  The conductive adhesive 345 electrically connecting the lower surface electrode layer in the extension portion 333 and the first surface 310 a of the low rigidity region 326 is provided in the adhesive retention region.

  According to such a configuration, the insulating adhesive 340 for mechanically joining the central portion 331 of the piezoelectric element 330 and the vibrating region 312, the lower electrode layer of the extending portion 333 of the piezoelectric element 330, and the low rigidity The conductive adhesive 345 that electrically connects the region 326 is mixed unexpectedly and effectively prevents the reliability of the electrical connection between the lower electrode layer of the piezoelectric element 330 and the elastic plate 310 from being impaired. can do.

  In the present embodiment, as shown in FIG. 38 and FIG. 39, the raised portions 328 are provided at two places, but the present invention is not limited to such a form. It is also possible to provide the raised portion 328 only at one place or at three or more places.

  The ultrasonic transducer 3A according to the present embodiment can be suitably manufactured, for example, by a manufacturing method to which the following modification is added, as compared with the method for manufacturing the ultrasonic transducer 1A according to the first embodiment.

  That is, in the manufacturing method of the present embodiment, the elastic plate etching step of forming the slit portion 17 half-etches the low rigidity region 326 in addition to the full etching process of etching away the slit portion 17. It has a half etching process (FIG. 40 (a)).

  In the half etching process, the region corresponding to the raised portion 328 is covered with a resist mask having a width slightly smaller than twice the side etching amount. Thereby, the ridge 328 can be left so that the position of the top thereof is lower than the vibration area 312 and the first surface 310 a of the restraint area 314, thereby preventing the contact with the lower surface of the piezoelectric element 330. it can.

  Next, the conductive adhesive 328 is applied in the adhesive retention area, and the insulating adhesive 340 is applied to the vibration area 312 (FIG. 40 (b)), and after the piezoelectric element 330 is attached (FIG. c) curing the conductive adhesive 328 and the insulating adhesive 340.

  Note that reference numeral 346 in FIG. 38 indicates that the conductive adhesive 345 is applied to the adhesive retention area in order to improve the reliability of the electrical connection between the conductive adhesive 345 and the elastic plate 310. Au plating is provided on the first surface of the adhesive retention area.

1A to 1 G, 2A to 2D, 3A Ultrasonic Transducer 10, 310 Elastic Plate 10a, 310a First Surface 10b, 310b Second Surface 11, 311 Base Region 12, 312 Vibration Region 14, 314 Restraint Region 16, 316 Boundary Region 17 slit part 17a, 17b first and second plate surface direction slit 18 bridge part 26, 326 low rigidity area 27 groove 28a opening part 28b connecting part 30, 330 piezoelectric element 40 sealing member 40a first sealing member 40b second Sealing member 41 Filled portion 42 Tubular portion 44 Closed portion 50 Sound absorbing material 60, 260 Rigid reinforcing plate 70 Protective member 72 Opening 75, 175, 275 Protective plate 77, 177 Through hole 80 Wiring body 82 Insulating layer 85 Wiring conductor 87 Conductivity Adhesive or Solder 88 Insulating Adhesive 110 Elastic Plate Forming Body 182 Insulating Layer Forming Member 185 Wiring Conductor Forming Material 210 Mass member 210a Mass member for restraint area 210b Mass member for base area 215 Bridge between restraint areas 216 Bridge between restraint area / base area 250 Spacer 262 Central part 263 Through hole 264 Extension part 276 Center part 278 Extension part 328 Bump Part 331 Central part 333 Extension part 340 Insulating adhesive 345 Conductive adhesive

Claims (36)

An elastic plate having a first surface and a second surface respectively facing the thickness direction one side and the other side, and capable of vibrating in the thickness direction;
A plurality of piezoelectric elements fixed in parallel to the first surface of the elastic plate;
A sealing member made of a polymer material provided on the first surface of the elastic plate so as to cover the plurality of piezoelectric elements;
The elastic plate includes a plurality of vibration regions in which the plurality of piezoelectric elements are mounted, a plurality of low rigidity regions respectively surrounding the plurality of vibration regions in plan view, and a plurality of low rigidity regions in plan view A plurality of constraining regions that surround, and a boundary region that divides one constraining region and an outer region located radially outward from the one constraining region,
The low-rigidity region is low-rigidity compared to the vibration region located radially inward of the region and the restraining region located radially outward of the region,
The boundary region has a slit portion that divides one constraining region and an outer region, and a bridge portion that mechanically connects the one constraining region to the outer region,
The sealing member is a plurality of cylindrical portions disposed so as to surround each of the plurality of piezoelectric elements in a plan view, and the first end face of the elastic plate crosses the slit portion on the first surface of the elastic plate A plurality of joined cylindrical portions, a plurality of closed portions respectively closing the free end sides of the plurality of cylindrical portions, and a filling portion extending from the proximal end surface of the cylindrical portion to the inside of the slit portion An ultrasonic transducer characterized by being.   The sealing member is formed of a first polymer material, and is formed of a first sealing member integrally forming the filling portion and the tubular portion, and a second polymer material, and the sealing portion is formed The ultrasonic transducer according to claim 1, further comprising: two sealing members.   The ultrasonic transducer according to claim 2, wherein the first polymer material has a lower viscosity than the second polymer material on the basis of a state before curing.   The ultrasonic transducer according to claim 1, wherein the plurality of cylindrical parts, the closed part and the filling part are integrally formed of the same polymer material.   The ultrasonic transducer according to any one of claims 1 to 4, wherein the low rigidity region has a groove that opens to the first surface of the elastic plate.   The low rigidity region includes an opening separating the vibration region and the restraining region, and a connecting portion connecting the vibration region and the restraining region, the opening and the connecting portion being the vibration. The ultrasonic transducer according to any one of claims 1 to 4, wherein the ultrasonic transducer is alternately provided along an outer peripheral edge of the region. The low-rigidity region is a concave thin-walled region in which the first surface is closer to the second surface than the first surface of the vibration region and the constraint region,
The piezoelectric element includes a central portion that overlaps with the vibration region in a plan view, and an extending portion that extends radially outward from the central portion and ends in the low-rigidity region in a plan view,
The lower surface electrode layer in the central portion is fixed to the first surface of the vibration region by an insulating adhesive, and the lower surface electrode layer in the extension portion is electrically connected to the first surface of the low rigidity region by a conductive adhesive. The ultrasonic transducer according to any one of claims 1 to 4, wherein the ultrasonic transducer is mechanically and mechanically connected. The bottom surface of the thin region is provided with a raised portion that is lower than the first surface of the vibration region and forms an adhesive retention region in cooperation with the inner surface of the thin region,
The conductive adhesive for electrically and mechanically connecting the lower surface electrode layer in the extension portion and the first surface of the low rigidity region is provided in the adhesive retention region. Item 8. The ultrasonic transducer according to Item 7.   The mass member fixed to the 1st surface of the said elastic board is provided so that the 1st surface of the said vibration area | region, the said low-rigid area | region, and the said boundary area | region may be open | released, The any one of Claim 1 to 8 characterized by the above-mentioned. Ultrasonic transducer described in. The mass member and the cylindrical portion are provided such that the upper end portion is separated from the first surface of the elastic plate than the upper surface of the piezoelectric element,
The closing portion covers the mass member and the cylindrical portion so that there is a gap between the upper surface electrode layer of the piezoelectric element,
A sound absorbing material made of a foamable resin is filled in a housing space for housing the piezoelectric element, which is surrounded by the first surface of the elastic plate, the mass member, and the closing portion. Ultrasonic transducer as described in. The cylindrical portion is provided such that the upper end portion is separated from the first surface of the elastic plate than the upper surface of the piezoelectric element, and the closed portion is a gap between the upper surface and the upper electrode layer of the piezoelectric element Provided to be
A sound absorbing material made of a foamable resin is filled in a housing space for housing the piezoelectric element, which is surrounded by the first surface of the elastic plate, the cylindrical portion, and the closing portion. The ultrasonic transducer according to any one of 1 to 8.   The ultrasonic transducer according to claim 1, wherein a protective member having an opening that opens the vibration region outward is fixed to the second surface of the elastic plate.   The ultrasonic transducer according to claim 12, wherein a rigid protective plate having a through hole provided at a position corresponding to the opening is fixed to an outer surface of the protective member.   The ultrasonic transducer according to any one of claims 1 to 13, wherein a rigid reinforcing plate is fixed to the outer surface of the closed portion. A protective member fixed to the second surface of the elastic plate, wherein the protective member is provided with an opening for opening the vibration area outward;
A rigid protective plate provided on the outer surface of the protective member, the protective plate having a through hole at a position corresponding to the opening of the protective member;
And a rigid reinforcing plate provided on the outer surface of the closed portion,
The protective plate has a central portion fixed to the outer surface of the protective member, and an extending portion extending outward in the plate surface direction from the central portion,
The reinforcing plate has a central portion fixed to the outer surface of the closed portion, and an extending portion extending outward in the plate surface direction from the central portion.
The ultrasonic transducer according to any one of claims 1 to 11, wherein the extension portion of the reinforcing plate and the extension portion of the protective plate are connected via a spacer. A protective member fixed to the second surface of the elastic plate, wherein the protective member is provided with an opening for opening the vibration area outward;
An end wall portion extending along the outer surface of the protection member and provided with a through hole at a position corresponding to the opening of the protection member, and the end wall portion surrounding the periphery of the protection member and the elastic plate A protective container including an extending peripheral wall portion;
The reinforcing plate connected to the peripheral wall portion so as to close the free end opening of the peripheral wall portion of the protective container in a state of covering the outer surface of the closed portion. Ultrasonic transducer described in.   The ultrasonic transducer according to claim 15 or 16, wherein the reinforcing plate is provided with a through hole communicating the inner surface and the outer surface. The elastic plate is a conductive metal plate,
The piezoelectric element has a piezoelectric body and a pair of upper surface electrode layers and lower surface electrode layers disposed on both sides in the thickness direction of the piezoelectric body,
The elastic plate is provided with a wiring body including an insulating layer provided on the first surface and a plurality of wiring conductors stacked on the insulating layer,
The lower electrode layer is mechanically and electrically bonded to the first surface of the elastic plate by a conductive adhesive, and the upper electrode layer is electrically connected to the corresponding wiring conductor by a conductive adhesive or solder. The ultrasonic transducer according to any one of claims 1 to 17, characterized in that:   Insulating adhesive is interposed between the conductive adhesive or solder electrically connecting the top electrode layer and the corresponding wiring conductor and the first surface of the elastic plate The ultrasonic transducer according to claim 18, characterized in that: The plurality of constraining regions are a constraining region group formed by m constraining regions (m is an integer of 1 or more) arranged along the first plate surface direction of the elastic plate, and orthogonal to the first plate surface direction. Having n rows (n is an integer of 1 or more) in the second plate surface direction, and m.times.n number of constrained regions developed by being provided,
The slit portion is positioned on both sides of the second plate surface direction of one piezoelectric element mounted in the vibration region in the one restraint region, and the pair of first plate surface directions extending along the first plate surface direction Including a slit and a pair of second plate surface direction slits located on both sides in the first plate surface direction of the one piezoelectric element and extending along the second plate surface direction,
The pair of first plate surface direction slits is longer than the first plate surface direction length of the one piezoelectric element, and the pair of second plate surface direction slits is longer than the second plate surface direction length of the pair of piezoelectric elements Long and
The bridge portion is formed at four locations defined by the end portions of the first plate surface direction slit and the second plate surface direction slit adjacent in the circumferential direction. The ultrasonic transducer in any one of 19.   21. The apparatus according to claim 20, wherein a single common slit is provided between the adjacent restraint areas, and the single common slit delimits both outer peripheries of the adjacent restraint areas. Ultrasonic transducer. An elastic plate having a first surface and a second surface respectively facing one side and the other side in the thickness direction and capable of vibrating in the thickness direction, and an upper surface disposed on both sides of the piezoelectric main body and the piezoelectric main body in the thickness direction A plurality of piezoelectric elements having an electrode layer and a lower surface electrode layer, wherein the lower surface electrode layer is fixed to the first surface of the plurality of vibration regions provided on the elastic plate, and provided on an insulating layer and the insulating layer A wiring body including a plurality of wiring conductors electrically connected to the upper electrode layers of the plurality of piezoelectric elements, and a polymer provided on the first surface of the elastic plate so as to cover the plurality of piezoelectric elements A sealing member made of a material, and a protective member fixed to the second surface of the elastic plate, wherein the protective member is provided with an opening for opening the vibration region outward, A plurality of low stiffnesses respectively surrounding the plurality of vibration regions in plan view A boundary that defines a region, a plurality of constrained regions respectively surrounding the plurality of low rigidity regions in a plan view, a constrained region in a plan view, and an outer region located radially outward from the constrained region The boundary region includes a slit portion separating the one constraining region and the outer region, and a bridge portion mechanically coupling the one constraining region to the outer region; The sealing member is a plurality of cylindrical portions respectively surrounding the plurality of vibration regions in plan view, and the plurality of cylinders joined to the first surface of the elastic plate at a position where the base end surface includes the boundary region. , A plurality of closed sections respectively closing the openings on the free end side of the plurality of cylindrical sections, and a filling section extending from the proximal end surface of the cylindrical section to the inside of the slit section. A method of manufacturing an acoustic transducer, comprising
Preparing a conductive elastic plate-forming body for forming the elastic plate;
A wiring body installation step of installing the wiring body;
An elastic plate etching step of etching the elastic plate forming body to form the slit portion and the low rigidity region;
A piezoelectric element mounting step in which the lower surface electrode layers of the plurality of piezoelectric elements are respectively bonded to the first surfaces of the plurality of vibration regions by a conductive adhesive;
Electrically connecting the tip portions of the plurality of wiring conductors to a corresponding upper surface electrode layer of the piezoelectric element with a conductive adhesive or solder;
A protection member installation step of fixing the protection member to the second surface of the elastic plate so as to close the second surface side of the slit portion while opening the vibration region outward through the opening;
And a sealing member installation step of installing the sealing member,
The wiring body installation step, the elastic plate etching step, and the piezoelectric element mounting step can be performed in any order.
The sealing member installation step includes a first sealing member installation step of installing a first sealing member that integrally forms the filling portion and the cylindrical portion, and a second sealing member that forms the blocking portion. And a second sealing member installation step of installing
In the first sealing member installation step, a process for installing a cylindrical part form frame that defines the area where the cylindrical part should be provided in a state where the upper part is open, and the side of the first surface of the elastic plate A method of manufacturing an ultrasonic transducer, comprising: applying a first polymer material to the inside of the cylindrical part form and curing it.   Before or after the first sealing member installation step and before the second sealing member installation step, a sound absorbing material is applied by applying and curing a foamable resin so as to surround the piezoelectric element. The method for manufacturing an ultrasonic transducer according to claim 22, further comprising a sound absorbing material setting step of setting.   In the second sealing member installation step, a second polymer material having a viscosity higher than that of the first polymer material is applied to the upper surface of the cylindrical portion and the sound absorbing material based on the state before curing. The method of claim 23, wherein the method is configured to cure. An elastic plate having a first surface and a second surface respectively facing one side and the other side in the thickness direction and capable of vibrating in the thickness direction, and an upper surface disposed on both sides of the piezoelectric body and the thickness direction of the piezoelectric body A plurality of piezoelectric elements having an electrode layer and a lower surface electrode layer, wherein the lower surface electrode layer is fixed to the first surface of the plurality of vibration regions provided on the elastic plate, and provided on an insulating layer and the insulating layer A wiring body including a plurality of wiring conductors electrically connected to upper surface electrode layers of the plurality of piezoelectric elements, a mass member fixed to the first surface of the elastic plate, and the plurality of piezoelectric elements A sealing member made of a polymer material provided on the first surface of the elastic plate, and a protection member fixed to the second surface of the elastic plate, the opening opening the vibration area outward And the elastic plate has a front surface in a plan view. A plurality of low rigidity regions respectively surrounding a plurality of vibration regions, a plurality of constrained regions respectively surrounding the plurality of low rigid regions in plan view, and a base region surrounding the entire plurality of constrained regions in plan view; A boundary region that is located between one constraining region and another constraining region and between adjacent constraining regions and a base region, and that delimits each of the plurality of constraining regions, A plurality of restraints respectively fixed to the plurality of restraint regions, and a slit portion that divides the restraint region from the periphery and a bridge portion that mechanically connects the one restraint region to the periphery; A mass member for a region and a mass member for a base region fixed to the base region, and the sealing member is a plurality of cylindrical portions that respectively surround the plurality of vibration regions in a plan view. A plurality of cylindrical portions joined to the first surface of the elastic plate at a position where the base end surface includes the boundary area, and a plurality of closed portions respectively closing openings on the free end side of the plurality of cylindrical portions A method of manufacturing an ultrasonic transducer, comprising: a filling portion extending from the proximal end surface of the cylindrical portion to the inside of the slit portion,
Preparing a conductive elastic plate-forming body for forming the elastic plate;
A wiring body installation step of installing the wiring body;
An elastic plate etching step of etching the elastic plate forming body to form the slit portion and the low rigidity region;
A piezoelectric element mounting step in which the lower surface electrode layers of the plurality of piezoelectric elements are respectively bonded to the first surfaces of the plurality of vibration regions by a conductive adhesive;
Electrically connecting the tip portions of the plurality of wiring conductors to a corresponding upper surface electrode layer of the piezoelectric element with a conductive adhesive or solder;
A mass member installation step including a process of fixing the mass member for the restraint area to each of the plurality of restraint areas and a process of fixing the mass member for the base area to the base area;
A protection member installation step of fixing the protection member to the second surface of the elastic plate so as to close the second surface side of the slit portion while opening the vibration region outward through the opening;
And a sealing member installation step of installing the sealing member,
The wiring body installation step, the elastic plate etching step, and the piezoelectric element mounting step can be performed in any order.
The mass member installation step and the protection member installation step can be performed in any order,
The sealing member installation step includes a first sealing member installation step of installing a first sealing member that integrally forms the filling portion and the cylindrical portion, and a second sealing member that forms the blocking portion. And a second sealing member installation step of installing
In the first sealing member installation step, the adjacent one of the mass member for the restraint area and the mass member for the other restraint area, and the space between the mass member for the restraint area and the mass member for the base area adjacent to each other, A method of manufacturing an ultrasonic transducer, comprising applying and curing a first polymer material from the side of a first surface of an elastic plate.   The mass member setting step includes connecting the upper end portions of the plurality of restraint region mass members, the base region mass member, and one adjacent restraint region mass member and the other restraint region mass members. A process of preparing a mass plate including an interregion bridge, and a restraint region / base region bridge connecting the upper end portions of adjacent restraint region mass members and base region mass members; A process of fixing to a predetermined position of the first surface of the first, and cutting the bridge between the constraining area and the bridge between the constraining area / base area to separate the mass members for constraining area and the mass members for base area 26. The method of manufacturing an ultrasonic transducer according to claim 25, further comprising processing.   The process of preparing the mass plate includes the process of preparing a plate-like metal block having a thickness corresponding to the height of the restraint area mass member and the base area mass member, and the process from the surface on one side of the metal block The method for manufacturing an ultrasonic transducer according to claim 26, further comprising: half etching the region corresponding to the inter-restraint region bridge and the restraining region / base region bridge.   Before or after the first sealing member installation step and before the second sealing member installation step, foaming is performed so as to surround the piezoelectric element in a space surrounded by one restraint region mass member 28. The method of manufacturing an ultrasonic transducer according to any one of claims 25 to 27, further comprising a sound absorbing material setting step of setting a sound absorbing material by applying and curing a conductive resin. Before or after the protective member is fixed to the second surface of the elastic plate, a central portion overlapping with the protective member in plan view and an extension portion extending outward in the plate surface direction from the central portion either in plan view A protective plate provided with a through hole communicating the opening of the protective member outward, and the protective plate in a state where the central portion of the protective plate is aligned with the through hole and the opening A protective plate setting step of fixing to the outer surface of the member;
Providing a reinforcing plate having a central portion overlapping with the elastic plate in plan view and an extending portion extending outward in the plate surface direction from the central portion, and provided with a through hole communicating the inner surface and the outer surface; And a reinforcement plate installation step of connecting the extension portion of the reinforcement plate and the extension portion of the protection plate via a spacer,
The second sealing member installation step is configured to apply and cure a second polymer material whose viscosity before curing is higher than that of the first polymer material through the through hole of the reinforcing plate. A method of manufacturing an ultrasonic transducer according to any of claims 25 to 28, characterized in that An end wall provided along the outer surface of the protective member either before or after the protective member is fixed to the second surface of the elastic plate and provided with a through hole corresponding to the opening of the protective member And a protective container having a peripheral wall portion extending from the end wall portion so as to surround the outer periphery of the protective member and the elastic plate, and the end wall portion in a state where the through hole and the opening are aligned. Attaching a protective container to the outer surface of the protective member.
A reinforcing plate extending along the elastic plate and provided with a through-hole communicating the inner surface and the outer surface is prepared, and the reinforcing plate is attached to the peripheral wall portion so as to close a free end opening of the peripheral wall portion of the protective container. And a reinforcement plate installation process connected to the
The second sealing member installation step is configured to apply and cure a second polymer material whose viscosity before curing is higher than that of the first polymer material through the through hole of the reinforcing plate. A method of manufacturing an ultrasonic transducer according to any of claims 25 to 28, characterized in that The peripheral wall portion of the protective container surrounds the outer periphery of the protective member and the elastic plate with a gap between the protective member and the outer periphery of the elastic plate,
In the second sealing member installation step, the second polymer material is added to the region located above the elastic plate in plan view, and the peripheral wall portion of the protective container and the outer periphery of the protective member and the elastic plate 31. The method of manufacturing an ultrasonic transducer according to claim 30, wherein the ultrasonic transducer is also applied to a gap between the two.   The ultrasonic transducer according to claim 30, wherein the peripheral wall portion of the protective container surrounds the outer periphery of the protective member and the elastic plate in a state of being in contact with the outer periphery of the protective member and the elastic plate. Manufacturing method. The low rigidity region is a groove opened to the side of the first surface provided along the outer peripheral edge of the vibration region, or a plurality of openings provided along the outer peripheral edge of the vibration region, Between the openings adjacent in the circumferential direction, there are a plurality of openings in which connection parts are left,
The ultrasonic wave according to any one of claims 22 to 32, wherein the elastic plate etching step forms the groove or the plurality of openings in the low rigidity region in addition to the formation of the slit portion. Method of manufacturing a transducer. The low-rigidity area is a concave thin-walled area open toward the first surface side, in which the first surface of the low-rigidity area is closer to the second surface than the vibration area and the first surface of the restraint area. ,
The bottom of the thin region is provided with a ridge which is lower than the vibration region and the first surface of the restraint region and which forms an adhesive retention region in cooperation with the inner surface of the thin region. And
The piezoelectric element overlaps with the vibration region in a plan view, and is joined to the first surface of the vibration region by an insulating adhesive, and extends radially outward from the center portion and in the plan view. And an extension portion terminating in the low rigidity area and joined to the first surface of the low rigidity area by the conductive adhesive disposed in the adhesive retention area;
In the elastic plate etching step, the elastic plate forming body is etched to form the slit portion, and half etching from the first surface side is performed on the region corresponding to the low rigidity region. And performing a half etching process to form the low rigidity area which is a concave thin area.
In the half etching process, the region corresponding to the vibration region and the region corresponding to the restricted region are covered with a mask, and the region corresponding to the raised portion is covered with a mask having a width smaller than twice the side etching amount. By performing in a fixed state, the low rigidity region is configured to be a concave thin region that opens to the first surface side, while leaving the protrusion lower than the vibration region and the restraint region on the bottom of the concave thin region. 33. A method of manufacturing an ultrasonic transducer according to any of claims 22 to 32, characterized in that:   In the wiring body installation step, an insulating layer forming member for forming the insulating layer and a wiring conductor forming member for forming the plurality of wiring conductors are provided on the first surface of the elastic plate, and the insulating layer forming member and the wiring conductor The ultrasonic transducer according to any one of claims 22 to 34, wherein an unnecessary portion of the forming member is removed by etching to form the insulating layer and the plurality of wiring conductors. Method. A step of applying an insulating resin between the tips of the plurality of wiring conductors and the corresponding piezoelectric elements prior to the electrical connection step,
The conductive adhesive or the solder in the electrical connection step is a state in which the insulating resin is interposed between the conductive adhesive or the solder and the first surface of the elastic plate. 36. The method of manufacturing an ultrasonic transducer according to any one of claims 22 to 35, wherein a front end portion of the wiring conductor is electrically connected to a corresponding upper surface electrode layer of the piezoelectric element.

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