Transducer and electronics

Abstract

A transducer includes a diaphragm support portion having a hollow portion, a vibrating diaphragm which is displaceable in a diaphragm thickness direction and is coupled to the diaphragm support portion, and a piezoelectric element on the vibrating diaphragm, having a pair of electrodes and a piezoelectric film sandwiched by the pair of electrodes, in a region overlapping the hollow portion, a plurality of first regions having a first total film thickness which is a sum of a diaphragm thickness of the vibrating diaphragm and a film thickness of the piezoelectric element, and a plurality of second regions having a second total film thickness which is a sum of the diaphragm thickness of the vibrating diaphragm and the film thickness of the piezoelectric element and is different from the first total film thickness, the first regions and the second regions being alternately arranged, one of the first regions being adjacent to a coupling portion of the diaphragm support portion and the vibrating diaphragm.

Description

TECHNICAL FIELD

[0001] The present embodiment relates to a transducer and an electronic device. BACKGROUND

[0002] Conventionally, a transducer that performs transmission or reception of sound waves or ultrasonic waves is known. The transducer is used as, for example, a speaker that transmits sound waves, and is mounted on a headphone or a wearable terminal, or the like.

[0003] For example, a sound emitting device suitable for a headphone is disclosed in Patent Literature 1. The sound emitting device includes a coil that generates a magnetic field, and a magnet that vibrates a diaphragm by interacting with the magnetic field generated by the coil.

[0004] In a speaker using a coil and a magnet, in order to generate a magnetic field, it is necessary to circulate a current in the coil, and power consumption becomes high. Therefore, a speaker using a piezoelectric element configured by sandwiching a piezoelectric film from both sides with a pair of electrodes has attracted attention (for example, Patent Literature 2). Such a speaker is manufactured using a semiconductor manufacturing technology, that is, MEMS (Micro Electro Mechanical Systems), which enables fine processing.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT LITERATURE

[0007] Patent Literature 1: Japanese Patent Application Publication No. 2018-170592

[0008] Patent Literature 2: Japanese Patent Application Publication No. 2012-105170 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] The piezoelectric element alternately repeats displacement to the upper side and displacement to the lower side together with the diaphragm by repeatedly applying a drive voltage to the pair of electrodes. Specifically, displacement in a manner that the front end side of the diaphragm is bent. By the vibration of the diaphragm, the air around the diaphragm vibrates, and the vibration of the air is output as sound waves. However, there is a case where, when a drive voltage is applied to the pair of electrodes, the piezoelectric element contracts, and the piezoelectric film of the piezoelectric element is bent (the diaphragm is also bent) in a direction parallel to the root (joint) of the diaphragm. This bending causes distortion in the vibration of the air. In addition, when the air around the diaphragm vibrates, if the internal space for displacement of the diaphragm is too large, air leakage occurs, and the vibration of the air is distorted. These distortions can affect the vibration of the air. This effect, for example, cancels out a part of the vibration, resulting in an undesirable situation where sound waves cannot be efficiently transmitted, or the like.

[0011] In addition, since the speaker assembly manufactured using the MEMS is small in size and has a fine shape, it is easy to become a fragile configuration. Therefore, due to an impact or the like from the outside, breakage can occur.

[0012] One aspect of the embodiment provides a transducer that can suppress bending of a piezoelectric film in a direction parallel to a joint portion of a diaphragm support portion and a diaphragm. In addition, a transducer that suppresses air leakage and is resistant to impact or the like is provided. In addition, an electronic device having a speaker assembly that makes the housing more compact is provided.

[0013] Technical means for solving the problem

[0014] One aspect of the embodiment is a transducer including a diaphragm support portion having a hollow portion, a diaphragm that is displaced in a film thickness direction and is joined to the diaphragm support portion, and a piezoelectric element on the diaphragm, having a pair of electrodes and a piezoelectric film sandwiched by the pair of electrodes, in a region overlapping the hollow portion, having a plurality of first regions having a first total film thickness that is a sum of a film thickness of the diaphragm and a film thickness of the piezoelectric element, and a plurality of second regions having a second total film thickness that is a sum of the film thickness of the diaphragm and the film thickness of the piezoelectric element different from the first total film thickness, the first regions and the second regions being alternately arranged, one of the first regions being adjacent to a joint portion of the diaphragm support portion and the diaphragm.

[0015] Another aspect of the embodiment is a transducer including a diaphragm support portion having a hollow portion, a diaphragm that is displaced in a film thickness direction and is joined to the diaphragm support portion, and a piezoelectric element on the diaphragm, having a pair of electrodes, a piezoelectric film sandwiched by the pair of electrodes, and a plurality of buffer layers on the pair of electrodes, in a region overlapping the hollow portion, having a first region not containing the buffer layers and a second region containing the buffer layers, the first regions and the second regions being alternately arranged, one of the first regions being adjacent to a joint portion of the diaphragm support portion and the diaphragm.

[0016] Another aspect of the embodiment is a transducer including a diaphragm support portion having a hollow portion, a diaphragm that is displaced in a film thickness direction and is joined to the diaphragm support portion, and a piezoelectric element on the diaphragm, having a pair of electrodes and a piezoelectric film sandwiched by the pair of electrodes, the diaphragm having a plurality of recesses, in a region overlapping the hollow portion, having a first region not containing the recesses and a second region containing the recesses, the first regions and the second regions being alternately arranged, one of the first regions being adjacent to a joint portion of the diaphragm support portion and the diaphragm.

[0017] Another aspect of the present embodiment is a transducer including: a piezoelectric element having a pair of electrodes and a piezoelectric film sandwiched by the pair of electrodes; a film body including a film support portion having a hollow portion and a vibrating film displaceable in a film thickness direction and coupled to the film support portion, and capable of laminating the piezoelectric element on the vibrating film; and an abutting member that restricts displacement of the vibrating film, an end portion of the piezoelectric element having an area overlapping the film support portion.

[0018] Another aspect of the present embodiment is an electronic device having: a speaker assembly including a substrate; and a bottomed cylindrical housing that houses the speaker assembly inside, the housing having a cylindrical portion and a bottom portion in contact with the cylindrical portion, the substrate being disposed at a portion of the cylindrical portion and a portion of the bottom portion, the bottom portion being separated from the cylindrical portion by the speaker assembly, the speaker assembly being provided with a vent in a film thickness direction, a space of the bottom portion communicating with an outside of the housing via the vent.

[0019] Another aspect of the present embodiment is an electronic device having: a speaker assembly including a substrate; and a bottomed cylindrical housing that houses the speaker assembly inside, the housing having a cylindrical portion and a bottom portion in contact with the cylindrical portion, the substrate being disposed at a portion of the cylindrical portion and a portion of the bottom portion, the bottom portion being separated from the cylindrical portion by the speaker assembly, the speaker assembly being provided with a vent in a side surface, a space of the bottom portion communicating with an outside of the housing via the vent.

[0020] Effects of Invention

[0021] According to the present embodiment, a transducer that suppresses bending of a piezoelectric film in a direction parallel to a coupling portion of a film support portion and a vibrating film can be provided. In addition, a transducer that suppresses air leakage and is resistant to impact and the like can be provided. In addition, an electronic device having a speaker assembly that miniaturizes a housing can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a cross-sectional view of one aspect of the transducer of the first embodiment.

[0023] Figure 2 is a plan view of one aspect of the transducer of the first embodiment.

[0024] Figure 3 is a cross-sectional view of another aspect of the transducer of the first embodiment.

[0025] Figure 4 is a plan view of another aspect of the transducer of the first embodiment.

[0026] Figure 5is a cross-sectional view of one aspect of a transducer of the second embodiment.

[0027] Figure 6 is a plan view of one aspect of a transducer of the second embodiment.

[0028] Figure 7 is a cross-sectional view of one aspect of a transducer of the third embodiment.

[0029] Figure 8 is a plan view of one aspect of a transducer of the third embodiment.

[0030] Figure 9 is a cross-sectional view of one aspect of a transducer of the fourth embodiment.

[0031] Figure 10 is a plan view of one aspect of a transducer of the fourth embodiment.

[0032] Figure 11 is a cross-sectional view of another aspect of a transducer of the fourth embodiment.

[0033] Figure 12 is a plan view of another aspect of a transducer of the fourth embodiment.

[0034] Figure 13 is a cross-sectional view of another aspect of a transducer of the fourth embodiment.

[0035] Figure 14 is a plan view of another aspect of a transducer of the fourth embodiment.

[0036] Figure 15 is a cross-sectional view of another aspect of a transducer of the fourth embodiment.

[0037] Figure 16 is a plan view of another aspect of a transducer of the fourth embodiment.

[0038] Figure 17 is a cross-sectional view of another aspect of a transducer of the fourth embodiment.

[0039] Figure 18 is a plan view of another aspect of a transducer of the fourth embodiment.

[0040] Figure 19 is a cross-sectional view of another aspect of a transducer of the fourth embodiment.

[0041] Figure 20 is a plan view of another aspect of a transducer of the fourth embodiment.

[0042] Figure 21 is a cross-sectional view of a transducer of the fifth embodiment.

[0043] Figure 22 is a plan view of the transducer of the fifth embodiment.

[0044] Figure 23 is a sectional view of the transducer of the first modification example.

[0045] Figure 24 is a plan view of the transducer of the first modification example.

[0046] Figure 25 is a sectional view of the transducer of the second modification example.

[0047] Figure 26 is a sectional view of the transducer of the third modification example.

[0048] Figure 27A is a sectional view of the slit 132 in the region 130 of the transducer of the third modification example, as viewed from the air inflow / outflow side.

[0049] Figure 27B is a sectional view of the slit 133 in the region 131 of the transducer of the third modification example, as viewed from the air inflow / outflow side.

[0050] Figure 28 is a sectional view of the transducer of the fourth modification example.

[0051] Figure 29 is a sectional view of the transducer of the fifth modification example.

[0052] Figure 30 is a plan view of the transducer of the fifth modification example.

[0053] Figure 31A is an overall view of an earphone of an example of the electronic device of the sixth embodiment.

[0054] Figure 31B is a view explaining a case of the earphone of the example of the electronic device of the sixth embodiment.

[0055] Figure 32 is a view explaining the structure of the speaker assembly of mounting example 1.

[0056] Figure 33 is a sectional view of the earphone of mounting example 1.

[0057] Figure 34 is a view explaining the structure of the speaker assembly of mounting example 2.

[0058] Figure 35 is a sectional view of the earphone of mounting example 2. DETAILED DESCRIPTION

[0059] Next, the present embodiment will be described with reference to the drawings. In the description of the drawings described below, the same or similar parts are marked with the same or similar reference numerals. However, the drawings are schematic illustrations, and it should be noted that the relationship between the thickness and planar dimensions of each constituent component and the like are different from reality. Therefore, the specific thickness and dimensions should be judged as appropriate with reference to the description below. In addition, of course, the drawings also include parts in which the relationship and proportions of the dimensions are different from each other.

[0060] In addition, the embodiments shown below are examples of devices or methods for embodying the technical idea, and are not content that limits the material, shape, configuration, arrangement, and the like of each constituent component. The present embodiment can be added with various changes within the scope of the claims.

[0061] One mode of the present embodiment will be described as follows.

[0062] <1> A transducer comprising: a film support portion having a hollow portion; a vibrating film which is displaceable in a film thickness direction and which is joined to the film support portion; and a piezoelectric element on the vibrating film, the piezoelectric element having a pair of electrodes and a piezoelectric film sandwiched by the pair of electrodes, the piezoelectric element having, in a region overlapping the hollow portion, a plurality of first regions having a first total film thickness which is a sum of a film thickness of the vibrating film and a film thickness of the piezoelectric element, and a plurality of second regions having a second total film thickness which is a sum of the film thickness of the vibrating film and the film thickness of the piezoelectric element different from the first total film thickness, the first regions and the second regions being alternately arranged, one of the first regions being adjacent to a joining portion of the film support portion and the vibrating film.

[0063] <2> A transducer comprising: a film support portion having a hollow portion; a vibrating film which is displaceable in a film thickness direction and which is joined to the film support portion; and a piezoelectric element on the vibrating film, the piezoelectric element having a pair of electrodes, a piezoelectric film sandwiched by the pair of electrodes, and a plurality of buffer layers on the pair of electrodes, the piezoelectric element having, in a region overlapping the hollow portion, a first region not containing the buffer layers and a second region containing the buffer layers, the first regions and the second regions being alternately arranged, one of the first regions being adjacent to a joining portion of the film support portion and the vibrating film.

[0064] <3> The transducer as recited in <2>, in one of the second regions, the buffer layers are divided.

[0065] <4> The transducer as recited in <2> or <3>, a width of the buffer layers of one of the second regions is greater than a width of the buffer layers of another of the second regions farther from the joining portion than one of the second regions.

[0066] <5> The transducer according to any one of <2> to <4>, wherein the width of the buffer layer of one of the second regions is larger toward the center portion in the longitudinal direction.

[0067] <6> The transducer according to any one of <2> to <5>, wherein the buffer layer comprises a plurality of layers of different materials.

[0068] <7> The transducer according to any one of <2> to <5>, wherein the number of layers constituting the buffer layer of one of the second regions is different from the number of layers constituting the buffer layer of the other of the second regions.

[0069] <8> A transducer comprising: a film support portion having a hollow portion; a vibrating film which is displaceable in a film thickness direction and which is coupled to the film support portion; and a piezoelectric element on the vibrating film, the piezoelectric element having a pair of electrodes and a piezoelectric film sandwiched by the pair of electrodes, the vibrating film having a plurality of recessed portions, a first region not including the recessed portions and a second region including the recessed portions in a region overlapping the hollow portion, the first region and the second region being alternately arranged, one of the first regions being adjacent to a coupling portion of the vibrating film and the film support portion.

[0070] <9> The transducer according to <8>, wherein the recessed portions are arranged on a back surface of the vibrating film.

[0071] <10> The transducer according to <8> or <9>, wherein the width of the recessed portion of one of the second regions is larger than the width of the recessed portion of the other of the second regions farther from the coupling portion than one of the second regions.

[0072] <11> The transducer according to any one of <8> to <10>, wherein the width of the recessed portion of one of the second regions is larger toward the center portion in the longitudinal direction.

[0073] <12> The transducer according to any one of <8> to <11>, wherein the depth of the recessed portion of one of the second regions is different from the depth of the recessed portion of the other of the second regions.

[0074] <13> The transducer according to any one of <1> to <12>, wherein one of the second regions is parallel with respect to the coupling portion.

[0075] <14> The transducer according to any one of <1> to <13>, wherein the width of one of the second regions is different from the width of the other of the second regions.

[0076] <15> The transducer according to any one of <1> to <14>, wherein the piezoelectric element has a piezoelectric gap.

[0077] <16> A transducer comprising: a piezoelectric element having a pair of electrodes and a piezoelectric film sandwiched by the pair of electrodes; a film body including a film support portion having a hollow portion and a vibrating film displaceable in a film thickness direction in connection with the film support portion, and capable of laminating the piezoelectric element on the vibrating film; and an abutting member that restricts displacement of the vibrating film, an end portion of the piezoelectric element having an area overlapping with the film support portion.

[0078] <17> The transducer as recited in <16>, the piezoelectric element and the vibrating film being disposed between the hollow portion and the abutting member.

[0079] <18> The transducer as recited in <16> or <17>, the abutting member having a first opening portion, an end portion of the first opening portion being provided with a circular arc.

[0080] <19> The transducer as recited in any one of <16> to <18>, the abutting member having a first opening portion, the transducer further comprising a first filter covering the first opening portion.

[0081] <20> The transducer as recited in <16> or <17>, the abutting member having a plurality of first through-holes.

[0082] <21> The transducer as recited in <20>, the first through-holes being smaller in hole size as they are farther away from the vibrating film.

[0083] <22> The transducer as recited in any one of <16> to <21>, a second side surface of the abutting member opposite to a first side surface of the abutting member on the end portion side being formed in a tapered shape.

[0084] <23> The transducer as recited in any one of <16> to <22>, the first side surface of the abutting member having a first gap on the end portion side.

[0085] <24> The transducer as recited in <23>, the first gap being a comb-tooth-like configuration.

[0086] <25> The transducer as recited in any one of <16> to <24>, further comprising a base sheet in contact with the film body, the film body being sandwiched by the base sheet and the abutting member.

[0087] <26> The transducer as recited in <25>, the base sheet having a second opening portion, an end portion of the second opening portion being provided with a circular arc.

[0088] <27> The transducer as recited in <25> or <26>, the base sheet having a second opening portion, the transducer further comprising a second filter covering the second opening portion.

[0089] <28> The transducer according to any one of <25> to <27>, wherein the substrate has a plurality of second through-holes.

[0090] <29> The transducer according to <28>, wherein the second through-holes are tapered in size away from the diaphragm.

[0091] <30> The transducer according to any one of <25> to <29>, wherein the first side surface of the membrane support portion is tapered in shape.

[0092] <31> The transducer according to any one of <25> to <30>, wherein the first side surface of the membrane support portion has a second slit on a side opposite the end portion.

[0093] <32> The transducer according to <31>, wherein the second slit is a comb-tooth shaped structure.

[0094] <33> The transducer according to any one of <16> to <32>, further comprising a wiring electrically connected to one of the pair of electrodes.

[0095] <34> The transducer according to <33>, wherein the wiring is electrically connected to one of the pair of electrodes via a through-hole provided in the membrane support portion.

[0096] <35> An electronic device having: a speaker assembly including a substrate; and a bottomed cylindrical housing that houses the speaker assembly inside, the housing having a cylindrical portion and a bottom portion in contact with the cylindrical portion, the substrate being disposed at a portion of the cylindrical portion and a portion of the bottom portion, the bottom portion being separated from the cylindrical portion by the speaker assembly, the speaker assembly being provided with a vent in a film thickness direction, a space of the bottom portion communicating with an outside of the housing via the vent.

[0097] <36> An electronic device having: a speaker assembly including a substrate; and a bottomed cylindrical housing that houses the speaker assembly inside, the housing having a cylindrical portion and a bottom portion in contact with the cylindrical portion, the substrate being disposed at a portion of the cylindrical portion and a portion of the bottom portion, the bottom portion being separated from the cylindrical portion by the speaker assembly, the speaker assembly being provided with a vent in a side surface, a space of the bottom portion communicating with an outside of the housing via the vent.

[0098] <37> The electronic device as recited in <35> or <36>, the speaker assembly having a transducer including: a piezoelectric element having a pair of electrodes and a piezoelectric film sandwiched by the pair of electrodes; a film body including a film support portion having a hollow portion and a vibrating film coupled to the film support portion and displaceable in a film thickness direction, and capable of laminating the piezoelectric element on the vibrating film; and an abutting member that restricts displacement of the vibrating film, an end portion of the piezoelectric element having an area overlapping with the film support portion.

[0099] The transducers of the first to fourth embodiments described below are configured mainly of a piezoelectric element and a film body. In some regions, by adjusting a total film thickness of a sum of a film thickness of the piezoelectric element and a film thickness of a vibrating film of the film body, regions having different total film thicknesses (for example, a first region having a first total film thickness and a second region having a second total film thickness, and the like) are formed, and the regions having different total film thicknesses (for example, the first region and the second region) are alternately arranged.

[0100] The transducers of the first to fourth embodiments are described using the drawings.

[0101] (First Embodiment)

[0102] Use Figure 1 and Figure 2 The structure of the transducer 1 of the present embodiment is described. The transducer 1 of the present embodiment is configured mainly of a piezoelectric element 10 and a film body 15. In the following description, the state of the transducer 1 shown in FIG. 1 is defined as a reference to define the upward and downward directions, but is not limited to the direction in which the transducer 1 is used. Figure 2

[0103] The piezoelectric element 10 is configured of a pair of electrodes 11, 12, a piezoelectric film 13 sandwiched by the pair of electrodes 11, 12, and a plurality of buffer layers 18 on the pair of electrodes 11, 12. The pair of electrodes 11, 12 and the piezoelectric film 13 have shapes corresponding to the shape of a vibrating film 16 described later, and are quadrangular in the example shown in FIG. 1. Figure 1 and Figure 2

[0104] Further, in the present specification and the like, the buffer layer is described as a part of the piezoelectric element, but is not limited thereto, and can be interpreted as not being a part of the piezoelectric element.

[0105] ​​The buffer layer 18 is formed in a strip shape on the electrode 11. The buffer layer 18 is formed parallel to the connection portion 21 between the membrane support portion 17 and the vibrating membrane 16, which will be described later. Furthermore, in this specification, "parallel" means that two straight lines are arranged at an angle of -5° to 5°, and also includes two straight lines forming two circles contained in concentric circles. In addition, if the end of the connection portion 21 and / or the buffer layer 18 is not a straight line, for example, it is wavy or serrated, it may deviate slightly from the parallel as long as it does not hinder the effect of the buffer layer 18 described later.

[0106] in addition, Figure 2 The end of the buffer layer 18 shown is located inside the end of the electrode 11, but it is not limited to this and can also be aligned with the end of the electrode 11.

[0107] The buffer layer 18 can also be formed using the same process as, for example, the wiring layer (not shown) and / or the insulating layer (not shown) formed during the manufacture of the transducer, or it can be formed using a hard material such as titanium. By using a hard material, the bending strength of the buffer layer 18 is increased, which can suppress the bending of the piezoelectric film 13 (and the vibrating film 16) in the direction parallel to the connection portion 21. In addition, the width, film thickness, and spacing between adjacent buffer layers 18 are not particularly limited.

[0108] A pair of electrodes 11 and 12 are formed, for example, thin films of conductive metals such as platinum, molybdenum, indium, or titanium. One electrode 11 is located on the upper side of the piezoelectric film 13 and is connected to an electrode pad 11a, which is a circuit pattern for applying a driving voltage to the electrode 11. The other electrode 12 is located on the lower side of the piezoelectric film 13 and is connected to an electrode pad 12a, which is a circuit pattern for applying a driving voltage to the electrode 12.

[0109] The piezoelectric film 13 is, for example, made of lead zirconate titanate (PZT) film. In addition to lead zirconate titanate, the piezoelectric film 13 can also be made of aluminum nitride (AlN), zinc oxide (ZnO), or lead titanate (PbTiO3).

[0110] The membrane 15 is composed of a vibrating membrane 16 and a membrane support portion 17. The membrane 15 is made of silicon (Si), for example. The vibrating membrane 16 and the membrane support portion 17 are integrally formed by etching the back side of the membrane 15.

[0111] The vibrating diaphragm 16 is composed of a thin film, and is positioned in the thickness direction, i.e., the direction relative to the normal of the vibrating diaphragm 16. Figure 1 The vertical direction on the paper: Z direction, and... Figure 2 The paper is arranged in a way that allows it to be displaced in the direction perpendicular to the front and back sides (Z direction). When viewed from a plane parallel to the diaphragm 16, the vibrating diaphragm 16 has a roughly quadrilateral shape.

[0112] The film support portion 17 has a four-cornered cylindrical inner peripheral surface that forms a cavity (hollow portion) 20. The diaphragm 16 is cut into the inner peripheral surface of the film support portion 17 on one side, whereby the diaphragm 16 is supported by the film support portion 17. The diaphragm 16 is connected to the upper end side of the film support portion 17.

[0113] Further, the transducer 1 has a slit 2. The slit 2 is a cutout that penetrates the vibration body formed by the piezoelectric element 10 and the diaphragm 16 in the thickness direction.

[0114] The diaphragm 16 has a cantilever shape that extends from the film support portion 17. The front end portion of the diaphragm 16 is configured as a free end. However, the diaphragm 16 can also be a double support beam shape in which both ends are fixed by the film support portion 17.

[0115] In the region overlapping the hollow portion 20, when a region not including the buffer layer 18 is taken as a first region 22 and a region including the buffer layer 18 is taken as a second region 23, the first region 22 and the second region 23 are alternately arranged. Further, one first region 22 is adjacent to the connecting portion 21. Also, the sum of the film thickness of the diaphragm 16 and the film thickness of the piezoelectric element 10 not including the buffer layer 18 in the first region 22, that is, the first total film thickness, is different from the sum of the film thickness of the diaphragm 16 and the film thickness of the piezoelectric element 10 including the buffer layer 18 in the second region 23, that is, the second total film thickness, that is, differs by the amount of the film thickness of the buffer layer 18.

[0116] In the transducer 1 thus configured, the piezoelectric element 10 is provided on the diaphragm 16 of the film body 15. That is, the lower electrode 12, the piezoelectric film 13, and the upper electrode 11 are sequentially stacked on the diaphragm 16. When a driving voltage is applied to the pair of electrodes 11, 12, respectively, a potential difference is generated between the pair of electrodes 11, 12. Due to this potential difference, the diaphragm 16 generates displacement. Specifically, displacement is generated in such a manner that the front end side of the diaphragm 16 is bent.

[0117] By repeatedly applying a driving voltage to the pair of electrodes 11, 12, the diaphragm 16 repeatedly and alternately performs displacement to the upper side and displacement to the lower side. The vibration of the diaphragm 16 causes the air around the diaphragm 16 to vibrate, and the vibration of the air is output as a sound wave.

[0118] By providing the above-described buffer layer 18, the buffer layer 18 mitigates the stress of the piezoelectric film 13 in the direction parallel with respect to the connecting portion 21, and can suppress the bending of the piezoelectric film 13 in this direction. Therefore, the occurrence of distortion of the diaphragm 16 can be suppressed, and the diaphragm 16 can be appropriately vibrated.

[0119] Further, in the present embodiment, as described above, Figure 1As shown, the buffer layer 18 is formed from the vicinity of the central portion of the diaphragm 16 to the front end, but is not limited thereto, and, for example, as shown in Figure 3 and Figure 4 As shown, for example, the buffer layer 18 can be formed from the vicinity of the connecting portion 21 to the front end of the transducer 1A.

[0120] (Second Embodiment)

[0121] The structure of the transducer 1B of the present embodiment will be described. The transducer 1B of the present embodiment differs from the transducer 1 of the first embodiment in that a diaphragm having a recess is used instead of using a buffer layer. In the present embodiment, points common to the first embodiment are referred to the description of the first embodiment, and hereinafter, the different points will be described. Figure 5 Figure 6 The diaphragm body 15 is constituted by the diaphragm 16a and the diaphragm support portion 17. The diaphragm 16a has a plurality of recesses 19 on the back surface side. The diaphragm 16a can be formed by etching on the back surface side of the diaphragm 16 of the first embodiment.

[0122] The diaphragm 16a has a bar shape in which a plurality of recesses 19 are arranged, and the recesses 19 are formed in parallel with respect to the connecting portion 21. In addition, the width, depth, and pitch width of the recesses 19 from each other, and the like are not particularly limited.

[0123] The diaphragm 16a has a bar shape in which a plurality of recesses 19 are arranged, and the recesses 19 are formed in parallel with respect to the connecting portion 21. In addition, the width, depth, and pitch width of the recesses 19 from each other, and the like are not particularly limited.

[0124] In the region overlapping with the hollow portion 20, when a region not containing the recesses 19 is the first region 24 and a region containing the recesses 19 is the second region 25, the first region 24 and the second region 25 are arranged alternately. In addition, one first region 24 is adjacent to the connecting portion 21. Further, the sum of the film thickness of the diaphragm 16a in the region other than the recesses in the first region 24 and the film thickness of the piezoelectric element 10 is the first total film thickness, and the sum of the film thickness of the diaphragm 16a in the region of the recesses 19 in the second region 25 and the film thickness of the piezoelectric element 10 is the second total film thickness, and the first total film thickness and the second total film thickness are different, that is, differ by the depth of the recesses 19.

[0125] By providing the recesses 19 described above, the recesses 19 relax the stress of the piezoelectric film 13 in the direction parallel with respect to the connecting portion 21, and the bending of the piezoelectric film 13 in that direction can be suppressed. Therefore, the occurrence of distortion of the diaphragm 16a can be suppressed, and the diaphragm 16a can be appropriately vibrated.

[0126] In addition, in the present embodiment, as shown in Figure 5 As shown, the recesses 19 are arranged from the vicinity of the central portion of the diaphragm 16a to the front end, but are not limited thereto, and, for example, the recesses 19 can be arranged from the vicinity of the connecting portion 21 to the front end.

[0127] ​(Third Embodiment)

[0128] Using Figure 7 and Figure 8 The structure of the transducer 1C of the present embodiment will be described. The transducer 1C of the present embodiment differs from the transducer 1 of the first embodiment in that the piezoelectric element 10 has the piezoelectric slit 14. In the present embodiment, the points common to the first embodiment are referred to the description of the first embodiment, and the following description will be made regarding the different points.

[0129] The piezoelectric element 10 has the piezoelectric slit 14 that penetrates the piezoelectric element 10 in the thickness direction. The piezoelectric slit 14 extends to the slit 2 along a direction perpendicular with respect to the joint portion 21. Further, in the present specification and the like, "perpendicular" means a state in which two straight lines are arranged at an angle of 85° or more and 95° or less. In addition, the perpendicular can be slightly deviated as long as it does not hinder the effects of the piezoelectric slit 14 described later.

[0130] The diaphragm 16 is divided in a direction parallel with respect to the joint portion 21 by the piezoelectric slit 14, and thus the bending of the piezoelectric film 13 in the direction can be suppressed. Therefore, the generation of the distortion of the diaphragm 16 can be suppressed, and the diaphragm 16 can be appropriately vibrated.

[0131] By providing the piezoelectric slit 14 in addition to the buffer layer 18, the bending of the piezoelectric film 13 on the diaphragm 16 can be further suppressed.

[0132] In addition, Figure 7 The buffer layer 18 illustrated is provided in a manner of straddling the piezoelectric slit 14, but is not limited thereto, and the buffer layer 18 can be divided by the piezoelectric slit 14.

[0133] (Fourth Embodiment)

[0134] The shape, pitch width, and the like of the buffer layer (or recess) of the transducer of the above-described embodiments can be appropriately changed, for example, as described below.

[0135] For example, the divided buffer layer 18a can be arranged on the electrode 11 as in the transducer 1D illustrated in Figure 9 and Figure 10 The width of the buffer layer 18b close to the joint portion 21 can be larger than the width of the buffer layer 18 away from the joint portion 21 as in the transducer 1E illustrated in Figure 11 and Figure 12 The buffer layer 18c as in the transducer 1F illustrated in Figure 13 and Figure 14 can be arranged on the electrode 11. The buffer layer 18c is larger in width toward the central portion in the long direction.

[0136] In addition, the buffer layer can also be composed of two or more layers of the same or different materials, for example, it can also be like... Figure 15 and Figure 16 As shown in the transducer 1G, a further buffer layer 18d can be provided on the buffer layer 18, or as... Figure 17 and Figure 18 As shown in the transducer 1H, the buffer layers 18 and 18d have a conical shape. Alternatively, they can be as follows: Figure 19 and Figure 20 As shown in the transducer 1I, a buffer layer 18d is provided on a portion of a plurality of buffer layers 18. For example, the number of buffer layers forming the buffer layer near the connecting portion 21 and the number of buffer layers forming the buffer layer farther away from the connecting portion 21 may be different.

[0137] Furthermore, when a rigid material is used in the buffer layer, the rigid material can hinder the contraction of the piezoelectric film 13 in the direction perpendicular to the connecting portion 21, resulting in reduced air vibration efficiency. Therefore, it is preferable to provide a soft material below the rigid material. Examples of soft materials include insulating layers such as silicon dioxide or resins. Figure 9 and Figure 10 The structure shown is composed of silicon dioxide as a soft material in buffer layer 18a and titanium as a hard material in buffer layer 18d.

[0138] Furthermore, although not shown, in the recess 19 of the second embodiment, for example, the width of the recess near the connecting portion 21 can be greater than the width of the recess away from the connecting portion 21. Also, a recess whose width increases towards the center along its long side can be provided. Additionally, recesses of different depths can be provided.

[0139] (Fifth Implementation Method)

[0140] use Figure 21 and Figure 22 The structure of the transducer 101 in this embodiment will be described. The transducer 101 in this embodiment is mainly composed of a piezoelectric element 110, a membrane 115, a contact member 118, and a substrate 119. In the following description, ... Figure 21 The state of the transducer 101 shown defines the up and down directions as a reference, but does not limit the direction in which the transducer 101 is used.

[0141] The piezoelectric element 110 comprises a pair of electrodes 111, 112 and a piezoelectric film 113 sandwiched between the pair of electrodes 111, 112. The pair of electrodes 111, 112 and the piezoelectric film 113 have shapes corresponding to the shape of the vibrating membrane 116 described later. Figure 21 and Figure 22 The example shown is a quadrilateral shape.

[0142] The abutting member 118 is disposed opposite the diaphragm 116. The abutting member 118 has a function of controlling displacement of the diaphragm 116. That is, the abutting member 118 controls displacement of the diaphragm 116 when the diaphragm 116 is displaced to the space 200 side by the abutting member 118 coming into contact with the diaphragm 116 or the piezoelectric element 110 on the diaphragm 116.

[0143] The distance of the abutting surface of the abutting member 118, which the diaphragm 116 contacts, from the diaphragm 116 is set based on the displacement of the diaphragm 116 when a rated voltage is applied to the piezoelectric element 110 (hereinafter referred to as "maximum displacement"). That is, the abutting surface of the abutting member 118 is set in such a manner that the diaphragm 116 or the piezoelectric element 110 (the stack of these is also referred to as a vibrating body) comes into contact with the abutting surface when a displacement greater than the maximum displacement is generated. Thus, the diaphragm 116 or the piezoelectric element 110 comes into contact with the abutting surface when a large displacement exceeding the maximum displacement is generated in the vibrating body due to a collision or the like, without impeding the usual displacement of the diaphragm 116 based on the vibration of the piezoelectric element 110.

[0144] The shape of the abutting surface is formed based on the displacement shape when the diaphragm 116 has been displaced. Thus, when the diaphragm 116 comes into contact with the abutting surface, the abutting surface comes into contact with the diaphragm 116 by the surfaces. For example, the abutting surface of the abutting member disposed in the space 200 can have a semispherical shape curved to the upper side.

[0145] An opening portion 118a is formed in the center of the abutting member 118. In addition, in the space 200 between the diaphragm 116 and the abutting member 118, air is vibrated due to displacement of the diaphragm 116, and the air circulates to the outside of the transducer 101 via the opening portion 118a. The distance (gap) of the abutting surface of the abutting member 118 from the diaphragm 116 when the air circulates in the space 200 is preferably small as long as the diaphragm 116 can be displaced up and down to that extent. For example, the gap is 5 to 30 μm. By making the gap small, air leakage can be suppressed, and the air can be vibrated efficiently. In addition, as shown in FIG. 2, the opening portion 118a preferably has a circular arc at the end portion. By the end portion of the opening portion 118a having a circular arc, stress concentration at the end portion can be alleviated. Figure 22

[0146] Each of the pair of electrodes 111, 112 is formed of a thin film of a metal having electrical conductivity, such as platinum, molybdenum, indium, or titanium. The one electrode 111 is located on the upper side of the piezoelectric film 113 and is connected to an electrode pad that is a circuit pattern for applying a drive voltage to the electrode 111. The other electrode 112 is located on the lower side of the piezoelectric film 113 and is connected to an electrode pad that is a circuit pattern for applying a drive voltage to the electrode 112.

[0147] ​The piezoelectric film 113 is made of, for example, lead zirconate titanate (PZT). In addition to lead zirconate titanate, aluminum nitride (AlN), zinc oxide (ZnO), or lead titanate (PbTiO3) can also be used for the piezoelectric film 113.

[0148] Electrode 111 is connected to wiring 121 through an opening in insulating film 120. Additionally, insulating film 122 is provided on wiring 121. Electrode 111 is electrically connected to electrode pads through an opening in insulating film 122. A contact member 118 is formed on insulating film 122 and film support portion 117. Furthermore, in this specification, "electrical connection" also includes connections via "components having some electrical functions." Here, "components having some electrical functions" is any component capable of transmitting and receiving electrical signals between connected objects, without particular limitation. For example, "components having some electrical functions" includes electrodes, wiring, switching elements, resistive elements, inductors, capacitors, and other components with various functions.

[0149] Wiring 121 is formed using a thin film of metal, for example. Insulating films 120 and 122 can be made of aluminum oxide, for example.

[0150] The membrane 115 is composed of a vibrating membrane 116 and a membrane support portion 117. The membrane 115 is made of silicon (Si), for example. The vibrating membrane 116 and the membrane support portion 117 are integrally formed by etching the back side of the membrane 115.

[0151] The vibrating diaphragm 116 is composed of a thin film, such that in the film thickness direction, i.e., the direction relative to the normal of the vibrating diaphragm 116 ( Figure 21 The vertical direction on the paper: Z direction, and... Figure 22 The paper is constructed in a way that allows it to move in the direction perpendicular to the front and back sides (Z direction). When viewed from a plane parallel to the diaphragm 116, the vibrating diaphragm 116 has a roughly quadrilateral shape.

[0152] The membrane support portion 117 has a quadrangular cylindrical inner peripheral surface that forms a space (hollow portion, cavity) 201. A vibrating membrane 116 is incised on one side of the inner peripheral surface of the membrane support portion 117, thereby supporting the vibrating membrane 116. The vibrating membrane 116 is connected to the upper end side of the membrane support portion 117.

[0153] Furthermore, the membrane support portion 117 has a region that overlaps with the end of the piezoelectric element 110, and the vibrating diaphragm 116 has a cantilever shape extending from the membrane support portion 117. The front end of the vibrating diaphragm 116 is configured as a free end. However, it is not limited to this; the vibrating diaphragm 116 may also be a double-support beam shape with both ends fixed by the membrane support portion 117.

[0154] The substrate 119 is in contact with the membrane support portion 117. In addition, an opening portion 119a is formed in the center of the substrate 119. In addition, in a space 201 surrounded by the diaphragm 116, the membrane support portion 117, and the substrate 119, air vibrates due to displacement of the diaphragm 116, and the air circulates to the outside of the transducer 101 via the opening portion 119a. In addition, as shown in Figure 22 The opening portion 119a preferably has a circular arc at the end portion. By having a circular arc at the end portion of the opening portion 119a, stress concentration at the end portion can be alleviated. The substrate 119 is composed of, for example, silicon (Si). In addition, the substrate 119 has a function of limiting displacement of the diaphragm 116.

[0155] In the transducer 101 having such a structure, the piezoelectric element 110 is provided on the diaphragm 116 of the membrane body 115. That is, the lower electrode 112, the piezoelectric film 113, and the upper electrode 111 are sequentially stacked on the diaphragm 116. When a drive voltage is applied to the pair of electrodes 111, 112, respectively, a potential difference is generated between the pair of electrodes 111, 112. The diaphragm 116 is displaced due to the potential difference. Specifically, the diaphragm 116 is displaced in a manner that the front end side of the diaphragm 116 is bent.

[0156] By repeatedly applying a drive voltage to the pair of electrodes 111, 112, the diaphragm 116 repeatedly alternately performs displacement to the space 200 side and displacement to the space 201 side. By vibration of the diaphragm 116, the air around the diaphragm 116 vibrates, and the vibration of the air is output as a sound wave.

[0157] In the present embodiment, the transducer 101 has the abutting member 118 that limits displacement of the diaphragm 116 by coming into contact with the diaphragm 116 or the piezoelectric element 110 when the diaphragm 116 is displaced in the film thickness direction. In addition, the substrate 119 also has a function of limiting displacement of the diaphragm 116.

[0158] According to such a structure, air leakage can be suppressed by the abutting member 118 and / or the substrate 119, and air can be efficiently vibrated. In addition, because displacement of the diaphragm 116 can be limited by the abutting member 118 and / or the substrate 119, excessive displacement of the diaphragm 116 due to impact or the like can be suppressed. Thus, occurrence of breakage or the like can be suppressed, so air leakage can be suppressed, and a transducer that is resistant to impact or the like can be obtained.

[0159] The transducer of the present embodiment is not limited to the above-described structure, and various modifications can be made. Hereinafter, modified examples of the transducer of the present embodiment will be described.

[0160] <First Modified Example>

[0161] By Figure 23 andFigure 24 The structure of the transducer 101A in this modified example is described. The transducer 101A in this modified example is similar to that described above. Figure 21 and Figure 22 The difference in the transducer 101 shown is the addition of a wiring 123 that connects to wiring 121. In this variant, with... Figure 21 and Figure 22 The common features of the transducer 101 shown are as described above; the differences will be described below.

[0162] Wiring 123 is connected to wiring 121 via a through hole provided in the membrane support portion 117. That is, wiring 123 is electrically connected to electrode 111 via wiring 121. However, it is not limited to this; for example, wiring 123 may be configured to be electrically connected to electrode 111 using wiring provided on the outer wall of membrane body 115. By providing wiring 123 on the back side of substrate 119, surface mounting is possible. Surface mounting does not occupy space compared to wire bonding, and is therefore suitable for transducer miniaturization.

[0163] <Second Variation>

[0164] use Figure 25 The structure of transducer 101B in this modified example is explained. The transducer 1 in this modified example is similar to the one described above. Figure 21 and Figure 22 The difference in the transducer 101 shown is that a filter 124 covering openings 118a and 119a is newly provided. In this modified example, the... Figure 21 and Figure 22 The common features of the transducer 101 shown are as described above; the differences will be described below.

[0165] The filter 124 is disposed on the upper surface side of the abutment member 118 with the opening 118a closed. Additionally, the filter 124 is disposed on the back side side of the substrate 119 with the opening 119a closed. The filter 124 is formed in a sheet shape and is made of a material that allows air to pass through. As the filter 124, a waterproof and breathable fabric such as non-woven fabric or expanded polytetrafluoroethylene (registered trademark) can be used. Furthermore, the filter 124 can be disposed on the lower surface side of the abutment member 118 or the upper surface side of the substrate 119, and, as in the third modification described later, it can also be disposed on the side of the abutment member 118 or the side of the membrane support 117.

[0166] By providing the filter 124, since the opening portion 118a and / or the opening portion 119a is closed by the filter 124, entry of dust or liquid and the like into the internal spaces 200 and 201 can be suppressed. In addition, since the filter 124 is formed of a material through which air can pass, the circulation of air based on the opening portion 118a and the opening portion 119a can be maintained.

[0167] <Third Modification>

[0168] Utilizing Figure 26 , Figure 27A and Figure 27B The structure of the transducer 101C of the present modification will be described. The transducer 101C of the present modification differs from the transducer 101A of the first modification described above in that an abutting member 128 is used instead of the abutting member 118, a film support portion 127 is used instead of the film support portion 117, and a substrate 129 is used instead of the substrate 119. Instead of the opening portion 118a and the opening portion 119a, the air of the spaces 200 and 201 is circulated to the outside via a slit 132 provided in the abutting member 128 and a slit 133 provided in the film support portion 127. Points common to the transducer 101A of the first modification in the present modification are referred to the description described above, and hereinafter, the points of difference will be described.

[0169] The abutting member 128a can be formed of the same material as the abutting member 118. For example, when a material is etched to form a groove portion that becomes the space 200, the slit is simultaneously formed, whereby the abutting member 128 can be formed. In addition, the material can be etched to form a groove portion that becomes the space 200, and thereafter, a portion of the inner side surface of the groove portion is etched to form the slit, whereby the abutting member 128 can be formed. From the viewpoint of the number of processes and cost, it is preferable to simultaneously form the groove portion that becomes the space 200 and the slit using one photomask.

[0170] In Figure 27A , a cross-sectional view as viewed from the air inflow and outflow side (left side in the drawing) of the slit 132 in the region 130 shown in Figure 26 is shown. As shown in Figure 27A , the slit 132 provided in the abutting member 128 is a comb-tooth shaped structure. If such a structure, entry of foreign matter (dust or liquid and the like) from the outside into the internal space 200 can be suppressed. In addition, the slit 132 can not be a comb-tooth shaped structure as long as it is a structure that can suppress entry of foreign matter from the outside into the internal space 200, and for example, can be a lattice shaped structure.

[0171] The membrane support portion 127 can use the same material as the membrane support portion 117. That is, the membrane body 115 is composed of the vibrating membrane 116 and the membrane support portion 127. Therefore, the vibrating membrane 116 and the membrane support portion 127 are integrally formed by etching the back side of the membrane body 115. When etching the back side of the membrane body 115 to form the groove that becomes the space 201, a slit is formed simultaneously, thereby forming the membrane support portion 127. Alternatively, the groove that becomes the space 201 can be formed by etching the back side of the membrane body 115, and then a portion of the inner side of the groove can be etched to form a slit, thereby forming the membrane support portion 127. From the viewpoint of process quantity and cost, it is preferable to use a single photomask to simultaneously form the groove that becomes the space 201 and the slit.

[0172] exist Figure 27B The middle indicates from Figure 26 A cross-sectional view of the airflow in and out of gap 133 in region 131 (right side of the paper). (See diagram below.) Figure 27B As shown, the slit 133 provided in the membrane support portion 127 has a comb-like structure. With such a structure, foreign objects (dust or liquid, etc.) can be prevented from entering the interior space 201 from the outside. In addition, as long as the slit 133 is a structure that can prevent foreign objects from entering the interior space 201 from the outside, it does not have to be a comb-like structure; for example, it can be a lattice-like structure.

[0173] Furthermore, the slit 133 is located diagonally opposite to the slit 132. Specifically, the side of the membrane support 127 with the slit 133 is located diagonally opposite to the side of the contact member 128 with the slit 132, across the vibrating membrane 116. With this configuration, the inflow and outflow of external air can be efficiently achieved.

[0174] <Fourth Variation>

[0175] use Figure 28 The structure of the transducer 101D in this modified example will be explained. The difference between the transducer 101D in this modified example and the transducer 101A in the first modified example described above is that an abutment member 138 is used instead of an abutment member 118, and a membrane support portion 137 is used instead of a membrane support portion 117. The commonalities between this modified example and the transducer 101A in the first modified example will be explained above; the differences will be explained below.

[0176] The abutting member 138 can use the same material as the abutting member 118. The abutting member 138 has an opening portion 138a, and a side surface of the abutting member 138 in the opening portion 138a is formed in a forward tapered shape. However, the side surface of the abutting member 138 in the opening portion 138a can also be formed in a reverse tapered shape. In addition, the abutting member 138 has a side surface 138b that is a reverse tapered shape as an abutting surface. By having the side surface 138b, it is possible to reduce the distance (gap) from the diaphragm 116. By reducing the gap, it is possible to suppress air leakage and efficiently vibrate air.

[0177] The film support portion 137 can use the same material as the film support portion 117. The film support portion 137 has a side surface 137a that is a tapered shape. The film body 115 is composed of the diaphragm 116 and the film support portion 137. Therefore, by etching the back surface side of the film body 115, the diaphragm 116 and the film support portion 137 are integrally formed. The back surface side of the film body 115 is etched to form a groove portion that becomes the space 201, and then a portion of the inner side surface of the groove portion is etched to form the side surface 137a, so that the film support portion 137 can be formed. By having the side surface 137a, it is possible to reduce the distance (gap) from the diaphragm 116. By reducing the gap, it is possible to suppress air leakage and efficiently vibrate air.

[0178] <5th Modification>

[0179] By using Figure 29 and Figure 30 , the structure of the transducer 101E of the present modification is described. The transducer 101E of the present modification differs from the transducer 101A of the above-described first modification in that the abutting member 148 is used instead of the abutting member 118, and the substrate 139 is used instead of the substrate 119. The points common to the transducer 101A of the first modification in the present modification are described in the above description, and hereinafter, the different points are described.

[0180] The abutting member 148 can use the same material as the abutting member 118. The abutting member 148 has an opening portion 148a in which a through-hole 148b is formed. The through-hole 148b is preferably made smaller in diameter as it is farther from the diaphragm 116. By having such a through-hole 148b, entry of foreign matter (dust or liquid, etc.) from the outside into the inside space 200 can be suppressed. Further, the through-hole 148b is preferably formed so that the diameter of the hole near the front end of the diaphragm 116 is larger, and the air near the front end portion of the diaphragm 116 whose displacement amount is larger can be vibrated more efficiently. Further, the through-hole 148b is preferably formed so that the density of holes of the same diameter near the front end portion of the diaphragm 116 is higher than that of other portions, and the air near the front end portion of the diaphragm 116 can be vibrated more efficiently.

[0181] The substrate 139 can use the same material as the substrate 119. The substrate 139 has an opening portion 139a in which a through-hole 139b is formed. The through-hole 139b is preferably made smaller in diameter as it is farther from the diaphragm 116. By having such a through-hole 139b, entry of foreign matter (dust or liquid, etc.) from the outside into the inside space 201 can be suppressed. Further, the through-hole 139b is preferably formed so that the diameter of the hole near the front end of the diaphragm 116 is larger, and the air near the front end portion of the diaphragm 116 whose displacement amount is larger can be vibrated more efficiently. Further, the through-hole 139b is preferably formed so that the density of holes of the same diameter near the front end portion of the diaphragm 116 is higher than that of other portions, and the air near the front end portion of the diaphragm 116 can be vibrated more efficiently.

[0182] As described above, the description and the drawings constituting a part of the disclosure are illustrative and should not be construed as limiting. Various alternative modifications and applications of the technology can be apparent to those skilled in the art from this disclosure.

[0183] (Sixth Embodiment)

[0184] An electronic device of the present embodiment will be described. The electronic device of the present embodiment has a speaker assembly and a housing that houses the speaker assembly. As an example of the electronic device, an earphone can be exemplified. Figure 31A The earphone 150 shown has an earpiece 151 and a housing 152.

[0185] Figure 31Bis a diagram in which the earphone 150 is removed from the earphone 150, and is a diagram illustrating the shape of the housing 152. The housing 152 is a bottomed cylindrical shape having a cylindrical portion 152a and a bottom portion 152b in contact with the cylindrical portion 152a. A speaker assembly is disposed in a portion of the cylindrical portion 152a and a portion of the bottom portion 152b. Hereinafter, the configuration of the housing 152 and the speaker assembly (mounting of the speaker assembly) will be described.

[0186] <Installation Example 1>

[0187] As shown in Figure 32 , the speaker assembly (transducer 101) is a structure in which the diaphragm 115 and the abutting member 118 are provided on the substrate 119. An air vent (specifically, the opening portion 118a and the opening portion 119a shown in Figure 33 , are provided in the film thickness direction of the transducer 101 (substrate 119, diaphragm 115, and abutting member 118) (direction indicated by an arrow in the drawing).

[0188] Figure 33 is a cross-sectional view of an earphone in which the transducer 101 is mounted in the housing 152. The substrate 119 is disposed in a portion of the cylindrical portion 152a and a portion of the bottom portion 152b, and the diaphragm 115 and the abutting member 118 are provided on the substrate 119. The substrate 119 has the opening portion 119a, and the abutting member 118 has the opening portion 118a. The diaphragm 115 is composed of a vibrating diaphragm and a diaphragm support portion. The bottom portion 152b is separated from the cylindrical portion 152a via the transducer 101, and the space of the bottom portion 152b is in communication with the outside of the housing 152 via the opening portion 118a and the opening portion 119a. The transducer 101 in this installation example can use, for example, the transducer 101 of the first embodiment shown in Figure 21 and Figure 22 , the space of the bottom portion 152b is in communication with the outside of the housing 152 via the opening portion 118a, the space 200, the space 201, and the opening portion 119a.

[0189] By being formed in a configuration in which the cylindrical portion 152a and the bottom portion 152b are separated via the transducer 101, the air flow between the cylindrical portion 152a and the bottom portion 152b is blocked. Thereby, the space in which other devices or a battery and the like can be mounted in the housing 152 can be flexibly used, and the housing 152 can be miniaturized.

[0190] <Installation Example 2>

[0191] As shown in Figure 34 , the speaker assembly (transducer 101) is a structure in which the diaphragm 115 and the abutting member 128 are provided on the substrate 129. An air vent (specifically, the opening portion 128a and the opening portion 129a shown in Figure 35The air flows in the direction indicated by the arrow in the drawing.

[0192] Figure 35 FIG. 13 is a cross-sectional view of an earphone in which the transducer 101 is mounted in the housing 152. The diaphragm 115 and the abutting member 128 are disposed on a part of the cylindrical portion 152a and a part of the bottom portion 152b. The diaphragm 115 is composed of a diaphragm and a diaphragm support portion. The abutting member 128 has a slit 132, and the diaphragm support portion of the diaphragm 115 has a slit 133. The bottom portion 152b is separated from the cylindrical portion 152a via the transducer 101, and the space of the bottom portion 152b is communicated with the outside of the housing 152 via the slit 132 and the slit 133. The transducer 101 of the present mounting example can use, for example, the transducer 101A shown in FIG. 2. Figure 26 The space of the bottom portion 152b is communicated with the outside of the housing 152 via the slit 132, the space 200, the space 201, and the slit 133 in the transducer 101C of the third modified example shown in FIG. 13.

[0193] By forming a configuration in which the cylindrical portion 152a is separated from the bottom portion 152b via the transducer 101, the air flow between the cylindrical portion 152a and the bottom portion 152b can be blocked. Thus, the space in which other devices or a battery or the like are mounted in the housing 152 can be flexibly used, and the housing 152 can be miniaturized.

[0194] (Other Embodiments)

[0195] As described above, the descriptions and the drawings constituting a part of the disclosure are examples and should not be construed as limiting. Various alternative embodiments, examples, and applications of the technology can be apparent to those skilled in the art from this disclosure.

[0196] For example, the transducer can be applied to a use of receiving a sound wave in addition to transmitting a sound wave. In addition, the transducer is not limited to a sound wave and can be applied to a use of transmitting or receiving an ultrasonic wave.

[0197] Explanation of Reference Numerals

[0198] 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 101, 101A, 101B, 101C, 101D, 101E transducer

[0199] 2, 132, 133 slit

[0200] 10, 110 piezoelectric element

[0201] 11, 12, 111, 112 electrode

[0202] 11a, 12a electrode pad

[0203] 13, 113 piezoelectric film

[0204] 14 piezoelectric gap

[0205] 15, 115 film body

[0206] 16, 16a, 116 diaphragm

[0207] 17, 117, 127, 137 film support portion

[0208] 18, 18a, 18b, 18c, 18d cushion layer

[0209] 19 recess

[0210] 20 hollow portion

[0211] 21 connecting portion

[0212] 22, 24 first region

[0213] 23, 25 second region

[0214] 118, 128, 138, 148 abutting member

[0215] 118a, 119a, 138a, 139a, 148a opening

[0216] 119, 129, 139 base sheet

[0217] 120, 122 insulating film

[0218] 121, 123 wiring

[0219] 124 filter

[0220] 130, 131 region

[0221] 137a, 138b side surface

[0222] 139b, 148b through hole

[0223] 150 earphone

[0224] 151 earpiece

[0225] 152 housing

[0226] 152a cylindrical portion

[0227] 152b bottom portion

[0228] 200, 201 space

Claims

1. A transducer, characterized by A piezoelectric element having a pair of electrodes and a piezoelectric film sandwiched by the pair of electrodes; A film body including a film support portion having a hollow portion and a vibrating film which is linked to the film support portion and is displaceable in a film thickness direction, and in which the piezoelectric element is capable of being laminated on the vibrating film; and An abutting member which restricts displacement of the vibrating film, an end portion of the piezoelectric element has an area which overlaps with the film support portion, the abutting member has an opening portion, an end portion of the opening portion is provided with a circular arc.

2. The transducer according to claim 1, wherein the piezoelectric element and the vibrating film are disposed between the hollow portion and the abutting member.

3. The transducer according to claim 1, wherein the opening portion is constituted by a first opening portion.

4. The transducer according to claim 1, wherein the opening portion is constituted by a first opening portion, the abutting member further has a first filter which covers the first opening portion.

5. The transducer according to claim 1, wherein the opening portion is constituted by a plurality of first through-holes.

6. The transducer according to claim 5, wherein the first through-holes become smaller in hole size as they are farther away from the vibrating film.

7. The transducer according to claim 1, wherein a second side surface of the abutting member opposite to a first side surface of the abutting member on the end portion side of the piezoelectric element is formed in a tapered shape. A piezoelectric element having a pair of electrodes and a piezoelectric film sandwiched by the pair of electrodes; A film body including a film support portion having a hollow portion and a vibrating film which is linked to the film support portion and is displaceable in a film thickness direction, and in which the piezoelectric element is capable of being laminated on the vibrating film; and 8. A transducer, characterized by An abutting member which restricts displacement of the vibrating film, an end portion of the piezoelectric element has an area which overlaps with the film support portion, a first side surface of the abutting member on the end portion side of the piezoelectric element has a first slit which allows air in a space on the end portion side to flow.

9. The transducer according to claim 8, wherein the first slit is a comb-tooth-like configuration.

10. The transducer according to any one of claims 1 to 9, further comprising: a substrate which is in contact with the film body, the film body is sandwiched by the substrate and the abutting member.

11. The transducer according to claim 10, wherein the substrate has a second opening portion, an end portion of the second opening portion is provided with a circular arc.

12. The transducer according to claim 10, wherein the substrate has a second opening portion, the transducer further has a second filter which covers the second opening portion.

13. The transducer according to claim 10, wherein the substrate has a plurality of second through-holes.

14. The transducer according to claim 13, wherein the second through-holes become smaller in hole size as they are farther away from the vibrating film.

15. The transducer according to claim 10, wherein a first side surface of the film support portion is formed in a tapered shape.

16. The transducer according to claim 10, wherein ​ ​ ​ ​ ​ The first side surface of the film support portion has a second slit on a side diagonal to the end portion.

17. The transducer according to claim 16, wherein: The second slit is a comb-tooth shaped configuration.

18. The transducer according to any one of claims 1 to 9, wherein: A wiring electrically connected to one of the pair of electrodes is further provided.

19. The transducer according to claim 18, wherein: The wiring is electrically connected to one of the pair of electrodes via a through-hole provided in the film support portion.

20. An electronic device, comprising: There is: A speaker assembly including the transducer according to claim 1 or 8, and a substrate in contact with the diaphragm; and A bottomed cylindrical housing in which the speaker assembly is accommodated inside, The housing has a cylindrical portion and a bottom portion in contact with the cylindrical portion, The substrate is disposed in a part of the cylindrical portion and a part of the bottom portion, The bottom portion is separated from the cylindrical portion by the speaker assembly, The speaker assembly is provided with a vent in a diaphragm thickness direction, The space of the bottom portion communicates with the outside of the housing via the vent.

21. The electronic device according to claim 20, wherein: The speaker assembly has a transducer, The transducer includes: A piezoelectric element having a pair of electrodes and a piezoelectric film sandwiched by the pair of electrodes; A diaphragm including a film support portion having a hollow portion and a vibrating film which is displaceable in a diaphragm thickness direction and is joined to the film support portion, and on which the piezoelectric element is capable of being laminated; and An abutting member which restricts displacement of the vibrating film, An end portion of the piezoelectric element has an area which overlaps with the film support portion.

22. An electronic device, comprising: There is: A speaker assembly including the transducer according to claim 1 or 8, and a substrate in contact with the diaphragm; and A bottomed cylindrical housing in which the speaker assembly is accommodated inside, The housing has a cylindrical portion and a bottom portion in contact with the cylindrical portion, The substrate is disposed in a part of the cylindrical portion and a part of the bottom portion, The bottom portion is separated from the cylindrical portion by the speaker assembly, The speaker assembly is provided with a vent in a side surface, The space of the bottom portion communicates with the outside of the housing via the vent.

23. The electronic device according to claim 22, wherein: The speaker assembly has a transducer, The transducer includes: A piezoelectric element having a pair of electrodes and a piezoelectric film sandwiched by the pair of electrodes; A diaphragm including a film support portion having a hollow portion and a vibrating film which is displaceable in a diaphragm thickness direction and is joined to the film support portion, and on which the piezoelectric element is capable of being laminated; and An abutting member which restricts displacement of the vibrating film, An end portion of the piezoelectric element has an area which overlaps with the film support portion.

Images