JP2017005525A - Ultrasonic device and manufacturing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic device capable of arranging piezoelectric elements highly densely, and a manufacturing method for the same.SOLUTION: An ultrasonic device 101 includes: a substrate 1 having a surface; a plurality of piezoelectric elements 21 which are flat plates having a first main surface 21a facing the surface of the substrate 1 and a second main surface 21b facing opposite the first main surface 21a, include piezoelectric materials 2, and are separated from each other; acoustic matching layers 3 arranged in the way that they are layered on a second main surface 21b in the respective plurality of piezoelectric elements 21; and two or more support members 4 mediated between the first main surface 21a and the surface of the substrate 1 in the respective plurality of piezoelectric elements 21. The respective plurality of piezoelectric elements 21 are supported by two or more support members 4 in the way that they are separated from the substrate 1 and, the piezoelectric elements 21 and the substrate 1 are conducted via the support member 4.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an ultrasonic device and a method for manufacturing the same. The term “ultrasonic device” as used herein includes any of a device for exclusively transmitting ultrasonic waves, a device for exclusively receiving ultrasonic waves, and a device for transmitting and receiving ultrasonic devices. It is a concept.

  Japanese Patent Application No. 61-175778 (Japanese Utility Model Publication No. 63-81273) discloses a device including a piezoelectric vibrator and an acoustic matching layer superimposed on the piezoelectric vibrator. . The acoustic matching layer is fixed to the mouth of the case, and the piezoelectric vibrator is disposed inside the case. Lead wires are drawn out from both main surfaces of the piezoelectric vibrator.

  Japanese Patent Laid-Open No. 4-336799 (Patent Document 2) discloses an apparatus including a transducer element and an acoustic matching layer superimposed on the transducer element. Electrical extraction is performed from two places on both ends of the apparatus by means of conductive wires.

Microfilm of Japanese Utility Model No. 61-175778 (Japanese Utility Model Application No. 63-81273) JP-A-4-336799

  In order to support the piezoelectric elements, when each piezoelectric element is provided with an individual case, it is difficult to arrange the plurality of piezoelectric elements at a high density because the case becomes an obstacle. Even if it can be arranged, the efficiency of the assembly work is poor.

  Therefore, an object of the present invention is to provide an ultrasonic apparatus capable of arranging piezoelectric elements at high density and a method for manufacturing the same.

  To achieve the above object, an ultrasonic apparatus according to the present invention includes a substrate having a surface, a first main surface facing the surface of the substrate, and a flat plate having a second main surface facing the first main surface. A plurality of piezoelectric elements that are separated from each other, include a piezoelectric body, an acoustic matching layer disposed so as to overlap the second main surface of each of the plurality of piezoelectric elements, and the plurality of piezoelectric elements Each having two or more conductive support members interposed between the first main surface and the surface of the substrate, each of the plurality of piezoelectric elements being separated from the substrate. It is supported by two or more support members, and the piezoelectric element and the substrate are electrically connected via the support members.

  Preferably, in the above invention, the piezoelectric element includes the first electrode disposed on the first main surface, the second electrode disposed on the second main surface, and the insulation while maintaining insulation with respect to the first electrode. A second electrode lead portion led out from the second electrode to the first main surface, wherein the first electrode and the second electrode sandwich the piezoelectric body, and the two of the two or more support members Are connected to the first electrode, and at least one of the two or more support members is connected to the second electrode lead-out portion.

In the present invention, preferably, the support member is softer than the piezoelectric body.
Preferably, in the above invention, the acoustic matching layer corresponding to one piezoelectric element is divided into a plurality of parts.

  Preferably, in the above invention, the vibration mode of the piezoelectric element is transverse effect spreading vibration, transverse effect length vibration, longitudinal effect length vibration, thickness longitudinal vibration, harmonic of thickness longitudinal vibration, or expansion / contraction deformation of the piezoelectric element. Alternatively, it is bending vibration in the thickness direction in which spread deformation and the acoustic matching layer are combined.

  In order to achieve the above object, a method for manufacturing an ultrasonic device according to the present invention corresponds to a plurality of piezoelectric elements, and includes a first piezoelectric main substrate having a flat plate shape having a first surface and a second surface facing the opposite side. Bonding the two surfaces and the acoustic matching layer parent substrate to each other, bonding or forming a plurality of conductive support members on the first surface of the piezoelectric parent substrate, By cutting into the first surface to the extent that the acoustic matching layer parent substrate is not completely divided while completely dividing each region corresponding to the piezoelectric element, and by joining the support member to the substrate, A step of creating a state in which the piezoelectric main substrate is supported by two or more of the support members so as to be separated from the substrate, and the individual piezoelectric elements and the substrate are electrically connected via the support members. And the acoustic matching layer parent And a step of cutting the portion that remained without disruption of.

  According to the present invention, since there can be no member around each acoustic transducer element, an ultrasonic device in which piezoelectric elements are arranged at high density can be obtained.

It is a fragmentary top view of the ultrasonic device in Embodiment 1 based on this invention. It is the 1st side view of the ultrasonic device in Embodiment 1 based on the present invention. It is a 2nd side view of the ultrasonic device in Embodiment 1 based on this invention. It is the top view seen from the 1st main surface side of the piezoelectric element with which the ultrasonic device in Embodiment 1 based on this invention is equipped. It is the top view seen from the 2nd main surface side of the piezoelectric element with which the ultrasonic device in Embodiment 1 based on this invention is equipped. It is explanatory drawing of a mode that a support member is joined to a piezoelectric element in order to obtain the acoustic conversion element contained in the ultrasonic device in Embodiment 1 based on this invention. It is explanatory drawing of a lateral effect spreading vibration. It is explanatory drawing of a lateral effect length vibration. It is explanatory drawing of a longitudinal effect length vibration. It is explanatory drawing of a longitudinal effect thickness vibration. It is an exploded view of the acoustic conversion element with which the ultrasonic device in Embodiment 2 based on this invention is equipped. It is sectional drawing of the acoustic conversion element with which the ultrasonic device in Embodiment 2 based on this invention is equipped. It is a perspective view of the acoustic conversion element with which the ultrasonic device in Embodiment 3 based on this invention is equipped. It is a perspective view of the acoustic conversion element with which the ultrasonic device in Embodiment 4 based on this invention is equipped. It is a top view of the 1st piezoelectric material contained in the ultrasonic device in Embodiment 4 based on this invention. It is a top view of the 2nd piezoelectric material contained in the ultrasonic device in Embodiment 4 based on this invention. It is a perspective view of the acoustic conversion element with which the ultrasonic device in Embodiment 5 based on this invention is equipped. It is a flowchart of the manufacturing method of the ultrasonic device in Embodiment 6 based on this invention. It is explanatory drawing of the 1st process of the manufacturing method of the ultrasonic device in Embodiment 6 based on this invention. It is explanatory drawing of the 2nd process of the manufacturing method of the ultrasonic device in Embodiment 6 based on this invention. It is explanatory drawing of the 3rd process of the manufacturing method of the ultrasonic device in Embodiment 6 based on this invention. It is explanatory drawing of the 4th process of the manufacturing method of the ultrasonic device in Embodiment 6 based on this invention. It is explanatory drawing of the 5th process of the manufacturing method of the ultrasonic device in Embodiment 6 based on this invention. It is explanatory drawing of the 6th process of the manufacturing method of the ultrasonic device in Embodiment 6 based on this invention. It is explanatory drawing of the 7th process of the manufacturing method of the ultrasonic device in Embodiment 6 based on this invention. It is explanatory drawing of the 8th process of the manufacturing method of the ultrasonic device in Embodiment 6 based on this invention. It is explanatory drawing of the 9th process of the manufacturing method of the ultrasonic device in Embodiment 6 based on this invention. It is explanatory drawing of the 10th process of the manufacturing method of the ultrasonic device in Embodiment 6 based on this invention.

(Embodiment 1)
(Constitution)
With reference to FIGS. 1-6, the ultrasonic apparatus in Embodiment 1 based on this invention is demonstrated. A partial plan view of the ultrasonic apparatus 101 is shown in FIG. A first side view of the ultrasonic apparatus 101 is shown in FIG. 2, and a second side view is shown in FIG. 2 corresponds to the view from the right side in FIG. 1, and FIG. 3 corresponds to the view from the lower side in FIG.

  The ultrasonic device 101 in the present embodiment is a device for transmitting, receiving, or both transmitting and receiving ultrasonic waves. The ultrasonic apparatus 101 includes an acoustic conversion array 53 and a circuit 55 connected thereto. The circuit 55 is, for example, a transmission drive circuit or a reception signal processing circuit. Alternatively, the circuit 55 may be a circuit that serves as both a transmission drive circuit and a reception signal processing circuit. The acoustic conversion array 53 includes a substrate 1 and a plurality of acoustic conversion elements 51 arranged on the substrate 1. The acoustic conversion element 51 includes the piezoelectric element 21 and the acoustic matching layer 3.

  The ultrasonic apparatus 101 according to the present embodiment includes a substrate 1 having a surface 1u, a flat plate having a first main surface 21a facing the surface 1u of the substrate 1 and a second main surface 21b facing the opposite of the first main surface 21a. A plurality of piezoelectric elements 21 that are in the shape of the piezoelectric body 2 and are spaced apart from each other, an acoustic matching layer 3 that is disposed so as to overlap the second main surface 21b in each of the plurality of piezoelectric elements 21, and a plurality of Each of the piezoelectric elements 21 includes two or more conductive support members 4 interposed between the first main surface 21 a and the surface 1 u of the substrate 1. Each of the plurality of piezoelectric elements 21 is supported by two or more support members 4 so as to be separated from the substrate 1. The piezoelectric element 21 and the substrate 1 are electrically connected via the support member 4. The board | substrate 1 here may have a certain electrode by the electrode pattern etc. on the surface 1u. In that case, the whole including such an electrode is called a “substrate”.

  Furthermore, an example is shown about the detailed structure of the piezoelectric element 21. FIG. FIG. 4 shows the piezoelectric element 21 as viewed from the first main surface 21a side. FIG. 5 shows the piezoelectric element 21 as viewed from the second main surface 21b side. As shown in FIG. 5, the second electrode 6b is provided on the entire surface of the second main surface 21b. As shown in FIG. 4, the first electrode 6a is provided in almost the entire region of the first main surface 21a. The first electrode 6 a on the first main surface 21 a is provided with a notch 17, and the second electrode lead portion 6 c drawn from the second electrode 6 b to the first main surface 21 a enters the notch 17. . The first electrode 6a and the second electrode lead portion 6c are not in contact with each other, and insulation between them is ensured. In addition, the shape of the notch 17 shown here is an example to the last, Comprising: It does not restrict to this shape.

  As shown in FIG. 4, in the center of the first main surface 21a, there is a region where the two support members 4 are to be joined. Each of the two support members 4 has a rectangular joint surface. The two support members 4 are arranged in parallel to each other. In the example shown here, the two support members 4 are parallel to each other. However, the arrangement is not limited to the parallel arrangement, and may be an arrangement having another positional relationship.

  FIG. 6 shows how the support member 4 is bonded to the piezoelectric element 21. Here, the acoustic matching layer 3 is already bonded to the piezoelectric element 21. The support member 4 is bonded to the surface of the piezoelectric element 21 opposite to the acoustic matching layer 3, that is, the first main surface 21a. One of the two support members 4 is joined to the first electrode 6a, and the other is joined to the second electrode lead portion 6c. Thus, the acoustic transducer 51 (see FIG. 3) is obtained.

  As shown in FIGS. 4 to 6, the structure in which the first electrode is provided with some notches and the second electrode lead portion is drawn is also referred to as a “partial electrode structure”.

(Action / Effect)
According to the present embodiment, it is possible to realize an ultrasonic apparatus that can be adapted to various vibration modes.

  In the present embodiment, conduction and support of the piezoelectric element 21 can be performed on the surface of the piezoelectric element 21 on the substrate 1 side, and there can be no member around each acoustic conversion element 51. The layers 3 can be arranged with high density. That is, according to the present embodiment, an ultrasonic device capable of arranging piezoelectric elements at high density can be provided. Therefore, when used for receiving ultrasonic waves, a small and high-resolution ultrasonic device can be obtained. When arranging the plurality of acoustic transducer elements 51 on the surface of the substrate 1, it is of course possible to arrange them in one row or two rows in an elongated manner. However, the arrangement is not limited to this, and arrangement with a larger number of rows is also easy. . Here, a case where a plurality of acoustic transducers are arranged in a matrix of m × n (m and n are integers) on the surface of the substrate has been described. However, the arrangement is not limited to the matrix arrangement, and any other arrangement may be used. There may be.

  As shown in this embodiment, it can be said that the ultrasonic apparatus 101 preferably has the following configuration. The piezoelectric element 21 includes a first electrode 6a disposed on the first main surface 21a, a second electrode 6b disposed on the second main surface 21b, and the second electrode 6b while maintaining insulation with respect to the first electrode 6a. And a second electrode lead portion 6c drawn to the first main surface 21a. The first electrode 6 a and the second electrode 6 b sandwich the piezoelectric body 2. At least one of the two or more support members 4 is connected to the first electrode 6a, and at least one other of the two or more support members 4 is connected to the second electrode lead portion 6c. . By adopting this configuration, the electrodes contributing to voltage application to both surfaces of the piezoelectric element 21 can be concentrated at a desired position on the first main surface 21a, and electrical connection to the piezoelectric element 21 can be efficiently performed. it can.

  When the partial electrode structure is adopted as shown in the present embodiment, the first electrode 6a and the second electrode lead portion 6c are separated by patterning after being formed as an integral conductor film in the same process. Therefore, an increase in processing steps can be avoided. Therefore, the manufacturing cost can be suppressed. In the present embodiment, the piezoelectric element 21 has been described as adopting a partial electrode structure. However, this is merely an example, and another electrode structure may be used. When the partial electrode structure is adopted, the vibration mode can be applied to at least lateral effect spreading vibration, thickness longitudinal vibration, harmonics of thickness longitudinal vibration, and bending vibration.

(Vibration mode)
In the ultrasonic device 101 in the present embodiment, the vibration mode of the piezoelectric element 21 is a transverse effect spreading vibration, a transverse effect length vibration, a longitudinal effect length vibration, a thickness longitudinal vibration, a harmonic of a thickness longitudinal vibration, or Any one of bending vibrations in the thickness direction in which expansion / contraction deformation or spreading deformation of the piezoelectric element and the acoustic matching layer are combined may be used. By adopting this configuration, transmission / reception in various vibration modes can be supported, and the degree of freedom in design is increased.

  The “lateral effect spreading vibration” is as shown in FIG. The piezoelectric element 21 has a plate shape. An arrow 91 indicates the polarization direction of the piezoelectric body included in the piezoelectric element 21. An arrow 95 indicates the vibration direction. As indicated by an arrow 91, the piezoelectric body of the piezoelectric element 21 is polarized in the thickness direction, and as indicated by an arrow 95, the piezoelectric element 21 vibrates so as to repeat expansion and reduction in the surface direction.

  The “lateral effect length vibration” is as shown in FIG. The piezoelectric element 21 has an elongated shape. The piezoelectric body of the piezoelectric element 21 is polarized in the thickness direction as indicated by an arrow 91, and the piezoelectric element 21 vibrates so as to repeat expansion and contraction in the longitudinal direction as indicated by an arrow 95.

  The “longitudinal effect length vibration” is as shown in FIG. The piezoelectric element 21 has an elongated shape, and a plurality of piezoelectric bodies are connected in series. The plurality of piezoelectric bodies included in the piezoelectric element 21 are polarized as indicated by arrows 91. That is, the adjacent piezoelectric bodies are polarized so as to be opposite to each other. Electrodes are arranged at the interfaces between the adjacent piezoelectric bodies, and these electrodes are electrically connected so as to have the same potential every other layer corresponding to the direction of polarization. At the time of transmission, by applying a transmission voltage using electrodes connected every other layer, the piezoelectric element 21 vibrates so as to repeat expansion and contraction in the longitudinal direction as indicated by an arrow 95. On the other hand, at the time of reception, signals are taken out from electrodes connected every other layer by expansion and contraction in the longitudinal direction indicated by an arrow 95.

  The “longitudinal effect thickness vibration” is as shown in FIG. The piezoelectric element 21 has a thick plate shape. As indicated by an arrow 91, the piezoelectric body of the piezoelectric element 21 is polarized in the thickness direction, and as indicated by an arrow 95, the piezoelectric element 21 vibrates so as to repeatedly expand and contract in the thickness direction.

(Embodiment 2)
(Constitution)
With reference to FIGS. 11-12, the ultrasonic apparatus in Embodiment 2 based on this invention is demonstrated. The configuration of the ultrasonic apparatus in the present embodiment is basically the same as that described in the first embodiment. Compared to the first embodiment, the following points are different.

  FIG. 11 shows an exploded view of the acoustic transducer provided in the ultrasonic apparatus according to the present embodiment, and FIG. 12 shows a cross-sectional view thereof. This acoustic conversion element includes a piezoelectric element 21i. Therefore, it can be said that the ultrasonic apparatus according to the present embodiment includes the piezoelectric element 21i. The piezoelectric element 21 i includes an insulating layer 8. As shown in FIG. 11, the first electrode 6a is provided in almost all regions except for the vicinity of one side of the first main surface 21a. As shown in FIGS. 11 and 12, the insulating layer 8 is disposed so as to partially overlap the first electrode 6a, and the second electrode lead portion 6c is disposed so as to partially overlap the insulating layer 8. Is done. The second electrode lead portion 6c is drawn from the second electrode 6b formed on the entire surface of the second main surface 21b, which is the main surface on the acoustic matching layer 3 side of the piezoelectric element 21i, to the first main surface 21a through the end face. It is a thing. Insulation is ensured by the insulating layer 8 between the first electrode 6a and the second electrode lead portion 6c. The point that the two support members 4 are joined to the center of the first main surface 21a is the same as that described in the first embodiment.

  Note that, as shown in FIGS. 11 to 12, a structure in which a portion where two electrodes overlap through some kind of insulating layer is also referred to as an “insulating layer structure”.

(Action / Effect)
In the present embodiment, since the piezoelectric element 21i is provided, more parts of the piezoelectric body 2 can be used as compared with the partial electrode structure described in the first embodiment. In the present embodiment, it is not necessary to provide a notch in the first electrode 6a.

  In the present embodiment, since almost all the part of the piezoelectric body can be used, a high-performance ultrasonic device can be realized.

(Embodiment 3)
(Constitution)
With reference to FIG. 13, the ultrasonic apparatus in Embodiment 3 based on this invention is demonstrated. The configuration of the ultrasonic apparatus in the present embodiment is basically the same as that described in the first embodiment. Compared to the first embodiment, the following points are different.

  FIG. 13 shows a perspective view of the acoustic transducer provided in the ultrasonic apparatus according to the present embodiment. This acoustic conversion element includes a piezoelectric element 21j. Therefore, it can be said that the ultrasonic apparatus according to the present embodiment includes the piezoelectric element 21j. The piezoelectric element 21j includes surface electrodes 7a and 7b on the first main surface 21a. The surface electrodes 7a and 7b are arranged through a gap without contacting each other. The piezoelectric element 21j includes a plurality of internal electrodes 9. The internal electrodes 9 are alternately arranged so as to extend from one end face and to extend from the other end face. That is, when viewed from the side, it seems that the two comb-shaped conductive structures are combined to face each other. By adopting this structure, some of the plurality of internal electrodes 9 are electrically connected to the surface electrode 7a, and the other internal electrodes 9 are electrically connected to the surface electrode 7b. One of the two support members 4 is joined to the surface electrode 7a, and the other one is joined to the surface electrode 7b. The two comb-shaped conductive structures may be formed of the same material, but in FIG. 13, in order to clarify the distinction between those having the same potential as the surface electrode 7a and those having the same potential as the surface electrode 7b , They are displayed with different hatching.

(Action / Effect)
In the present embodiment, since the plurality of internal electrodes 9 are provided in the piezoelectric element 21j, it can be applied to the harmonics of the lateral effect length vibration, the longitudinal effect thickness vibration, and the longitudinal effect thickness vibration.

(Embodiment 4)
(Constitution)
With reference to FIGS. 14-16, the ultrasonic device in Embodiment 4 based on this invention is demonstrated. The configuration of the ultrasonic apparatus in the present embodiment is basically the same as that described in the first embodiment. Compared to the first embodiment, the following points are different.

  FIG. 14 is a perspective view of an acoustic conversion element provided in the ultrasonic apparatus according to the present embodiment. Therefore, it can be said that the ultrasonic apparatus according to the present embodiment includes the piezoelectric element 21k. The piezoelectric element 21 k includes a surface electrode 7. The piezoelectric element 21k has a structure in which a plurality of piezoelectric bodies 2 are stacked. An internal electrode 10 formed as a conductor film is interposed between the piezoelectric bodies 2. The plurality of piezoelectric bodies 2 are polarized in the thickness direction as indicated by arrows 91. As shown in FIG. 14, adjacent ones of the plurality of piezoelectric bodies 2 are polarized in opposite directions. FIG. 15 shows a plan view of one of the plurality of piezoelectric bodies 2 taken out. FIG. 16 shows a plan view of another one of the plurality of piezoelectric bodies 2 taken out. A conductor film as the internal electrode 10 covers most of the surface of the piezoelectric body 2, but a region not covered by the internal electrode 10 is formed at one corner. In this region, an interlayer connection conductor 11 is formed. Interlayer connection conductor 11 is, for example, a via hole or a through hole.

(Action / Effect)
In the present embodiment, since the plurality of internal electrodes 9 are provided in the piezoelectric element 21k, it can be applied to the harmonics of the lateral effect length vibration, the longitudinal effect thickness vibration, and the longitudinal effect thickness vibration. In this embodiment, it is advantageous when a two-dimensional array is formed.

(Embodiment 5)
(Constitution)
With reference to FIG. 17, the ultrasonic apparatus in Embodiment 5 based on this invention is demonstrated. The configuration of the ultrasonic apparatus in the present embodiment is basically the same as that described in the first embodiment. Compared to the first embodiment, the following points are different.

  FIG. 17 is a perspective view of the acoustic conversion element provided in the ultrasonic apparatus according to the present embodiment. Therefore, it can be said that the ultrasonic apparatus according to the present embodiment includes the piezoelectric element 21n. The piezoelectric element 21n includes an electrode 13 on the main surface facing the acoustic matching layer 3, and includes electrodes 12a and 12b on the main surface facing the opposite side to the acoustic matching layer 3. The piezoelectric element 21 n includes the piezoelectric body 2. The piezoelectric body 2 is sandwiched between the electrodes 12 a and 12 b and the electrode 13. The piezoelectric body 2 is polarized in the thickness direction as indicated by an arrow 91. The piezoelectric body 2 may be integrated, but as shown in FIG. 17, the direction of polarization changes for every half of the region. In the piezoelectric body 2 included in the piezoelectric element 21n, the directions of polarization are reversed in the left half and the right half in FIG.

(Action / Effect)
In the present embodiment, a piezoelectric element 21n is provided. In the present embodiment, an increase in processing steps can be avoided. Therefore, the manufacturing cost can be suppressed. In this embodiment, the vibration mode is advantageous for lateral effect spreading vibration and lateral effect length vibration.

  As described above with reference to some embodiments, there are a plurality of options for the wiring structure of the piezoelectric element. It is conceivable to arrange the support member 4 at a position where the amplitude of the piezoelectric body 2 is small. It is also possible to arrange the support member 4 or the interlayer connection conductor at a position suitable for suppressing unnecessary vibration. In this way, it is possible to flexibly respond to the performance requirements. Such a large number of options makes it possible to meet cost requirements.

  The material of the piezoelectric body 2 included in the piezoelectric element may be piezoelectric ceramics such as lead zirconate titanate (PZT), PZT ternary system, lead titanate (PT), potassium sodium niobate (KNN). Alternatively, a piezoelectric single crystal such as quartz, lithium tantalate (LT), lithium niobate (LN), langasite, magnesium niobate / lead tantalate (PMN-PT) solid solution may be used.

  The acoustic matching layer 3 may be a resin alone or a mixture of a substance having a specific gravity smaller than that of the resin and the resin. The substance having a specific gravity smaller than that of the resin here may be, for example, a hollow particle.

  The acoustic matching layer 3 has an acoustic impedance smaller than that of the piezoelectric element and larger than that of the acoustic medium gas. The acoustic matching layer 3 preferably has a thickness corresponding to a quarter wavelength or a vicinity of 3/4 wavelength of a longitudinal wave of an ultrasonic frequency to be used.

  The substrate 1 may be a single printed circuit board in which a conductive film or conductive foil is provided on an insulating base material. Or what attached the electrical wiring board to base materials, such as a hard metal heavy, may be used.

(Embodiment 6)
(Production method)
With reference to FIGS. 18 to 28, a method of manufacturing an ultrasonic apparatus according to the sixth embodiment of the present invention will be described. FIG. 18 shows a flowchart of the method for manufacturing the ultrasonic device in the present embodiment.

  The manufacturing method of the ultrasonic device in the present embodiment corresponds to the plurality of piezoelectric elements 21 and acoustically corresponds to the second surface of the plate-like piezoelectric parent substrate 202 having the first surface and the second surface facing the opposite side. A step S1 for bonding the matching layer parent substrate 203, a step S2 for bonding or forming a plurality of conductive support members 4 on the first surface of the piezoelectric main substrate 202, and the piezoelectric main substrate 202 for each piezoelectric substrate. Step S3 in which the acoustic matching layer parent substrate 203 is cut from the first surface to the extent that the acoustic matching layer parent substrate 203 is not completely divided while being divided for each region corresponding to the element 21, and the support member 4 is bonded to the substrate 1 The piezoelectric main substrate 202 is supported by two or more support members 4 so as to be separated from the substrate 1, and the individual piezoelectric elements 21 and the substrate 1 are electrically connected via the support members 4. Step S4 to create and sound And a step S5 for cutting the portion that remained without disruption of the matching layer mother board 203.

  The method for manufacturing the ultrasonic device in the present embodiment will be described in more detail. Here, as an example, the ultrasonic device 101 described in Embodiment 1 is manufactured. Since the ultrasonic device 101 includes the piezoelectric element 21, the manufacturing process of the piezoelectric element 21 will be described in detail among the manufacturing methods.

  First, as shown in FIG. 19, a flat piezoelectric main substrate 201 is prepared. The surface of the piezoelectric main substrate 201 is preferably increased in smoothness by, for example, lapping.

  As shown in FIG. 20, electrode patterns 206 are formed on both the front and back surfaces of the piezoelectric main substrate 201. The electrode pattern 206 is a conductor film. The electrode pattern 206 is formed by a metal film, for example. The method for forming the electrode pattern 206 may be printing or baking. Of the front and back surfaces of the piezoelectric main substrate 201, a surface that is visible on the upper side in FIG. 20 is a first surface, and a surface that is hidden on the lower side is a second surface. As shown in FIG. 20, on the first surface, the electrode pattern 206 is a combination of a plurality of patterns corresponding to the first main surface 21a (see FIG. 4). On the second surface, the electrode pattern 206 covers the entire surface.

Necessary polarization processing is performed on the piezoelectric main substrate 201.
A strip shape is cut out as shown in FIG. In this way, the piezoelectric main substrate 202 is obtained in place of the piezoelectric main substrate 201. Both the front and back surfaces of the piezoelectric main substrate 202 will be referred to as “first surface” and “second surface”. That is, the surface that is visible on the upper side in FIG. 21 is the first surface, and the surface that is hidden on the lower side is the second surface.

  As shown in FIG. 22, the electrode 14 is formed on the end face. The end face electrode 14 can be formed by performing sputtering as shown by an arrow.

  As step S <b> 1, as shown in FIG. 23, the acoustic matching layer parent substrate 203 is bonded to the piezoelectric parent substrate 202. The acoustic matching layer parent substrate 203 is bonded so as to overlap the piezoelectric parent substrate 202.

  As step S2, a conductive support member 4 is formed as shown in FIG. In forming the support member 4, it may be formed by printing a conductive resin. Alternatively, it may be formed by dispensing and curing. After the material to be the support member 4 is cured, the shape may be corrected by cutting or polishing. The support member 4 may be formed in advance as another solid member and bonded to the surface of the piezoelectric main substrate 202.

  As step S3, as shown in FIG. 25, a cut 209 is provided so that the piezoelectric main substrate 202 is completely divided and the acoustic matching layer parent substrate 203 is cut in the middle of the thickness direction. The “thickness direction” here means the vertical direction in FIG. In step S3, the piezoelectric main substrate 202 is completely divided for each region corresponding to each piezoelectric element, and the acoustic matching layer parent substrate 203 is cut from the first surface to such an extent that it is not completely divided. . In the example shown in FIG. 25, when making a cut from the first surface, the cut is made perpendicular to the first surface, but this is merely an example, and is not necessarily vertical. For example, a cut may be made obliquely from the first surface. When the process up to step S3 is performed, a part of the acoustic matching layer parent substrate 203 is connected, so that the structure shown in FIG.

  In step S4, the structure shown in FIG. 25 is turned over and attached to the substrate 1 as shown in FIG. The substrate 1 is prepared separately. Necessary wiring 16 is formed on the surface of the substrate 1 in advance. At the time of this sticking, it sticks so that support and conduction may be performed through the support member 4. As a result, the individual piezoelectric elements 21 and the substrate 1 are electrically connected via the support member 4. If attention is paid to each region of each piezoelectric element 21, the piezoelectric main substrate is supported by two or more support members 4 so as to be separated from the substrate 1. In FIG. 26, a plurality of structures shown in FIG. 25 are attached to the surface of one substrate 1. Here, the structures shown in FIG. 25 are arranged in a line on one substrate 1, but the arrangement is not limited to this.

  As step S5, as shown in FIG. 27, the portion of the acoustic matching layer parent substrate 203 remaining without being completely divided is cut. That is, as shown by an arrow 96, cutting is performed by a known technique. In this way, an individual acoustic matching layer 3 is obtained.

  As shown in FIG. 28, an acoustic conversion array in which a plurality of acoustic conversion elements 51 are arranged on the surface of the substrate 1 is obtained. Further, a circuit 55 (see FIG. 3) necessary for driving and / or receiving is connected to the acoustic transducer array. In this way, the ultrasonic device 101 (see FIG. 3) is obtained.

In addition, the following can be said about all the embodiments so far.
The support member 4 interposed between the piezoelectric element and the substrate is preferably softer than the piezoelectric body 2 included in the piezoelectric element. The support member 4 may be either a resin having rubber elasticity such as silicone or urethane, or a rigid resin such as epoxy. As already described, the support member 4 has conductivity. Two or more support members 4 are disposed for bipolar use on the entire surface or a part of the surface of the piezoelectric element facing the substrate 1. The installation location of the support member 4 is preferably in the vicinity of a node point when the piezoelectric element vibrates. The position and size of the support member 4 are preferably set to a position and size that do not inhibit the vibration of the piezoelectric element. By securing the support and conduction using the support member 4, it is possible to avoid the problem that the vibration of the piezoelectric element leaks to the substrate, adjacent elements and the like.

  The acoustic matching layer 3 corresponding to one piezoelectric element is preferably divided into a plurality of parts. In order to improve the efficiency of the amplitude and vibration area of the acoustic radiation surface, the acoustic matching layer 3 may be divided into a plurality of parts in one piezoelectric element. Alternatively, the acoustic matching layer 3 may have a step or an inclination in one piezoelectric element. By increasing the efficiency of the amplitude and vibration area of the acoustic radiation surface, it is possible to increase the sound pressure and sensitivity.

In addition, you may employ | adopt combining suitably two or more among the said embodiment.
In addition, the said embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and includes all modifications within the scope and meaning equivalent to the terms of the claims.

  1 substrate, 1u (substrate) surface, 2 piezoelectric body, 3 acoustic matching layer, 4 support member, 6a first electrode, 6b second electrode, 6c second electrode lead-out portion, 7, 7a, 7b surface electrode, 8 insulation Layer, 9, 10 internal electrode, 11 interlayer connection conductor, 12a, 12b, 13 electrode, 14 end face electrode, 16 wiring, 17 notch, 21, 21, i, 21j, 21k, 21n piezoelectric element, 21a (for piezoelectric element) 1 main surface, 21b second main surface (of piezoelectric element), 51 acoustic transducer, 53 acoustic transducer array, 55 circuit, 91, 95, 96 arrow, 101 ultrasonic device, 201, 202 piezoelectric substrate, 203 acoustic Matching layer parent substrate, 206 electrode pattern, 209 cut.

Claims (6)

A substrate having a surface;
A plurality of piezoelectric elements having a first main surface facing the surface of the substrate and a second main surface facing the opposite side of the first main surface, including a piezoelectric body and spaced apart from each other;
An acoustic matching layer disposed to overlap the second main surface in each of the plurality of piezoelectric elements;
Each of the plurality of piezoelectric elements comprises two or more conductive support members interposed between the first main surface and the surface of the substrate;
Each of the plurality of piezoelectric elements is supported by the two or more support members so as to be separated from the substrate, and the piezoelectric elements and the substrate are electrically connected via the support members. Sonic device. The piezoelectric element includes a first electrode disposed on the first main surface, a second electrode disposed on the second main surface, and the second electrode from the second electrode while maintaining insulation with respect to the first electrode. A second electrode lead portion led out to one main surface, the first electrode and the second electrode sandwich the piezoelectric body,
At least one of the two or more support members is connected to the first electrode, and at least one other of the two or more support members is connected to the second electrode lead-out portion. The ultrasonic device according to claim 1.   The ultrasonic device according to claim 2, wherein the support member is softer than the piezoelectric body.   The ultrasonic apparatus according to claim 1, wherein the acoustic matching layer corresponding to one piezoelectric element is divided into a plurality of parts.   The vibration mode of the piezoelectric element is a transverse effect spread vibration, a transverse effect length vibration, a longitudinal effect length vibration, a thickness longitudinal vibration, a harmonic of a thickness longitudinal vibration, or a stretching deformation or a spread deformation of the piezoelectric element and an acoustic matching. The ultrasonic device according to claim 1, wherein the ultrasonic vibration is bending vibration in a thickness direction in which the layers are combined. A step of bonding the second surface of the flat piezoelectric parent substrate having a first surface and a second surface facing the opposite side to the plurality of piezoelectric elements and the acoustic matching layer parent substrate;
Bonding or forming a plurality of conductive support members on the first surface of the piezoelectric main substrate;
A step of cutting from the first surface to such an extent that the acoustic matching layer parent substrate is not completely divided while the piezoelectric body parent substrate is completely divided into regions corresponding to individual piezoelectric elements;
By joining the support member to the substrate, the piezoelectric main substrate is supported by two or more of the support members so as to be separated from the substrate, and between the individual piezoelectric elements and the substrate is the support member. Creating a conductive state through
And a step of cutting a portion of the acoustic matching layer parent substrate remaining without being divided.

Images