JP2020088008A - Vibration device and electronic apparatus - Google Patents

Abstract

To provide a vibration device and electronic apparatus in which electrical reliability is hard to decrease.SOLUTION: A vibration device 100 includes a vibration part 1 having a piezoelectric element 10, and a wiring member 50 electrically connected with the piezoelectric element 10. The piezoelectric element 10 has a piezoelectric body 11, internal electrodes 19, 21, 23, and external electrodes 13, 15. The piezoelectric body 11 has principal surfaces 11a, 11b facing each other, and a lateral face 11e adjoining the principal surfaces 11a, 11b, respectively, and extending in the opposite direction thereof. The external electrodes 13, 15 are placed on the principal surface 11a. The wiring member 50 is located on the external electrodes 13, 15, and has a first region R1 joined to external electrodes 13, 15, a second region R2 joined to the principal surface 11a, and a third region R3 located between the first and second regions R2, and separated from the principal surface 11a.SELECTED DRAWING: Figure 4

Description

One embodiment of the present invention relates to a vibrating device and electronic equipment.

A piezoelectric device including a piezoelectric element, a vibrating member to which the piezoelectric element is joined, and a wiring member electrically connected to the piezoelectric element is known (for example, Patent Document 1). The wiring member has one end connected to the end surface of the vibrating member and the other end connected to an electronic device on which the vibrating device is mounted. One end of the wiring member is physically connected to the diaphragm and is electrically connected to the piezoelectric element. The other end of the wiring member is electrically and physically connected to the connector, for example.

Japanese Patent Laid-Open No. 04-070100

In the vibrating device described in Patent Document 1, the reliability of the vibrating device may be reduced as described below. Since one end of the wiring member is physically connected to the vibrating member, vibration is transmitted from the vibrating member. Since the other end of the wiring member is physically connected to the external device, it does not easily vibrate. Therefore, when the vibrating member vibrates, a mechanical load acts on the connection point between one end of the wiring member and the vibrating member. When a mechanical load acts on the connection point, the connection strength between the wiring member and the vibration member may be reduced. When the connection strength between the wiring member and the vibrating member decreases, for example, the wiring member and the vibrating member may separate from each other, and the electrical connection between the piezoelectric element and the wiring member may be interrupted.

One aspect of the present invention aims to provide a vibrating device in which electrical reliability is less likely to decrease.

A vibrating device according to one aspect of the present invention includes a vibrating portion having a piezoelectric element, and a wiring member electrically connected to the piezoelectric element, and the piezoelectric element includes a piezoelectric element body and a piezoelectric element body. The piezoelectric element has an inner electrode arranged inside and an outer electrode electrically connected to the inner electrode, and the piezoelectric body has a first main surface and a second main surface facing each other, and And a side surface that is adjacent to each of the first main surface and the second main surface and extends in the facing direction of the first main surface and the second main surface, and the external electrode is disposed on the first main surface. And the wiring member is located on the external electrode, and the first region joined to the external electrode, the second region joined to the first main surface, the first region and the second region And a third region that is located between and is separated from the first main surface.

In one of the above aspects, the wiring member has a second region joined to the first main surface of the piezoelectric element body in addition to the first region joined to the external electrode. Therefore, even if the vibrating device vibrates, a mechanical load is unlikely to act on the joint between the first region and the external electrode. Therefore, peeling between the first region and the external electrode is unlikely to occur.

Further, the wiring member has a third region located between the first region and the second region and separated from the first main surface of the piezoelectric element body. Therefore, for example, even when the first region and the external electrode are joined by a conductive joining member and the second region and the first main surface of the piezoelectric element are joined by an insulating joining member, insulation is achieved by the third region. A gap is secured between the flexible joining member and the conductive joining member. As a result, it is possible to prevent the insulating bonding member from pushing away the conductive bonding member and entering between the first region and the external electrode, resulting in poor conduction.

From the above, in the above-described one aspect, electrical connection between the external electrode and the wiring member is secured. Therefore, the electrical reliability of the vibrating device does not easily deteriorate.

In the above one aspect, the first main surface has a rectangular shape, and the wiring member extends along the long side of the first main surface when viewed from the opposite direction, and has a short length of the first main surface. The second region may intersect with the side and be joined to one end of the first main surface in the long side direction. In this case, since the first main surface has a rectangular shape, the displacement amount of the piezoelectric element is the largest at the center of the first main surface in the long side direction, and is the largest at both ends of the first main surface in the long side direction. Get smaller. Therefore, the displacement amount of the second region is smaller than that in the case where the second region is joined to the end portion of the first main surface in the short side direction. In the wiring member, the outer region connected to the opposite side of the second region from the third region tends to be displaced along with the displacement of the second region, but the vibration of the outer region does not coincide with the vibration of the piezoelectric element. Therefore, the vibration of the piezoelectric element may be hindered. In the above-mentioned one aspect, since the displacement amount of the second region is relatively small, the displacement of the external region connected to the second region is suppressed. Therefore, the vibration of the piezoelectric element is less likely to be disturbed, and the amplitude of the piezoelectric element can be increased.

In the above one aspect, the wiring member further has a fourth region supported by the support portion and a fifth region located between the second region and the fourth region, and the long-side direction The interval between the first region and the second region in may be shorter than the interval between the second region and the fourth region in the long side direction. In this case, the third region is easily deformed following the vibration of the piezoelectric element, and the strain of the wiring member can be concentrated in the play of the fifth region. Therefore, the amplitude of the piezoelectric element can be increased.

In the above-mentioned one mode, you may further have a holding part which holds both ends of a vibrating part in the long side direction of the 1st principal surface. In this case, the amplitude at the central portion of the vibrating portion in the long side direction can be further increased.

In the above one aspect, the distance between the second region and the first main surface in the facing direction may be gradually increased as the second region is separated from the third region. In this case, the distance between the second region and the first main surface is between the second region and the first main surface, as compared with the case where the distance between the third region and the first main surface is constant. The volume of the joining member provided can be increased. Thereby, in the wiring member, the vibration of the external region connected to the opposite side of the second region from the third region is easily absorbed. Therefore, the vibration of the piezoelectric element is less likely to be disturbed, and the amplitude of the piezoelectric element can be further increased.

In the above one aspect, a joining member joining the second region to the first main surface may be further provided, and the joining member may have a side surface portion provided on the side surface. In this case, since the bonding member is provided not only on the first main surface but also on the side surface, the bonding strength between the second region and the piezoelectric element is improved. As a result, even when the vibrating device vibrates, the mechanical load is less likely to act on the joint between the first region and the external electrode. Therefore, peeling between the first region and the external electrode does not occur easily.

In the above one aspect, the maximum value of the distance between the first main surface and the second region in the facing direction may be larger than the maximum value of the distance between the first main surface and the first region in the facing direction. In this case, the wiring member is easily deformed smoothly, and the amplitude of the piezoelectric element can be more effectively increased.

In the one aspect, the vibrating section may further include a vibrating member to which the piezoelectric element is joined. In this case, the vibration of the piezoelectric element can be increased.

In the above one aspect, the external electrode may be arranged in the central portion of the first main surface. In this case, the piezoelectric element can be vibrated in good balance.

An electronic apparatus according to one aspect of the present invention includes the above vibrating device.

In the one aspect, since the vibrating device is included, the electrical reliability is unlikely to decrease.

According to one aspect of the present invention, it is possible to provide a vibrating device and an electronic device that provide a vibrating device in which electrical reliability is less likely to decrease.

It is a perspective view of a vibrating device according to an embodiment. It is a disassembled perspective view of the vibration device of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 1. It is sectional drawing which expands and shows a part of FIG. It is an exploded perspective view showing composition of a piezoelectric element. It is a top view of a connection structure and a piezoelectric element. It is a bottom view of a connection structure. It is a partially expanded sectional view of a vibrating device according to a modification.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. In the description, the same elements or elements having the same function will be denoted by the same reference symbols, without redundant description.

FIG. 1 is a perspective view of a vibrating device according to an embodiment. FIG. 2 is an exploded perspective view of the vibrating device of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. FIG. 4 is a cross-sectional view showing a part of FIG. 3 in an enlarged manner. As shown in FIGS. 1 to 4, the vibrating device 100 includes a vibrating section 1, a connecting structure 2 connected to the vibrating section 1, and a case 3 in which the vibrating section 1 is arranged. The vibrating device 100 is used as, for example, a speaker or a buzzer. The vibrating device 100 is provided in an electronic device such as a television or a smartphone.

The case 3 is made of a resin material such as an acrylic resin, a vinyl chloride resin, or a molding resin. The case 3 is, for example, a rectangular parallelepiped box member having an open upper surface. The case 3 has a rectangular plate-shaped bottom portion 3a, a pair of side portions 3b facing each other, and a pair of side portions 3c facing each other.

The bottom portion 3a has a rectangular shape having a pair of long sides and a pair of short sides when viewed in the thickness direction. The rectangular shape includes, for example, a shape in which each corner is chamfered and a shape in which each corner is rounded. In the following, the long side direction of the bottom portion 3a is the X direction, the short side direction of the bottom portion 3a is the Y direction, and the thickness direction of the bottom portion 3a is the Z direction.

The length of the bottom portion 3a in the X direction is 33 mm, for example. The length of the bottom portion 3a in the Y direction is, for example, 18 mm. The length of the bottom portion 3a in the Z direction is, for example, 1.5 mm. A rectangular recess 3d is formed in the center of the upper surface of the bottom 3a when viewed from the Z direction. The length of the recess 3d in the X direction is, for example, 15 mm. The length of the recess 3d in the Y direction is, for example, 10 mm. The length (depth) in the Z direction of the recess 3d is 1.0 mm, for example.

The pair of side portions 3b has a rectangular plate shape and extends along the Z direction from the long side portion of the bottom portion 3a. The facing direction of the pair of side portions 3b coincides with the Y direction. A rectangular through hole 3e that penetrates the side portion 3b in the thickness direction (Y direction) is formed in the one side portion 3b. In FIG. 3, the illustration of the through hole 3e is omitted. The sound generated by the vibrating device 100 is transmitted to the outside of the case 3 mainly through the through hole 3e. The pair of side portions 3c has a rectangular plate shape and extends along the Z direction from the short side portion of the bottom portion 3a. The facing direction of the pair of side portions 3c coincides with the X direction. The lengths of the side portions 3b and 3c in the Z direction are the same, for example, 7.6 mm.

The case 3 further includes a support portion 3f that supports the connection structure 2. The support portion 3f projects from the end of the one side portion 3c opposite to the bottom portion 3a to the outside of the case 3 along the X direction.

The vibrating portion 1 is arranged on the bottom portion 3a. In the present embodiment, the vibrating portion 1 is surrounded by the pair of side portions 3b and the pair of side portions 3c on the bottom portion 3a. The vibrating section 1 is housed in the case 3. The vibrating section 1 includes a piezoelectric element 10 and a vibrating member 12 joined to the piezoelectric element 10.

The vibrating member 12 is made of, for example, a metal such as Ni—Fe alloy, Ni, brass, or stainless steel. In this embodiment, the vibration member 12 is a plate-shaped member. The vibrating member 12 has a pair of main surfaces 12a and 12b facing each other in the Z direction. The vibrating member 12 is arranged such that the outer edge of the vibrating member 12 is located outside the outer edge of the recess 3d when viewed from the Z direction. The vibrating member 12 completely covers the recess 3d.

The main surface 12b faces the bottom portion 3a in the Z direction. The main surface 12b is joined (bonded) to the bottom portion 3a by an adhesive layer 60 made of, for example, an epoxy resin or an acrylic resin. The adhesive layer 60 does not contain a conductive filler and has electrical insulation. The main surface 12b is joined to the peripheral edge of the recess 3d of the bottom 3a and is supported by the peripheral edge of the recess 3d.

In other words, the bottom portion 3a has both end portions 1a of the vibrating portion 1 in the long side direction (X direction) of the main surface 12a and both end portions 1b of the vibrating portion 1 in the short side direction (Y direction) of the main surface 12a. It functions as a holding unit. In the present embodiment, the end portion 1a is the end portion of the vibrating member 12 in the long side direction (X direction), and the end portion 1b is the end portion of the vibrating member 12 in the short side direction (Y direction). The bottom portion 3a may not hold both end portions 1b.

Each main surface 12a, 12b has a rectangular shape having a pair of long sides and a pair of short sides. That is, the vibrating member 12 has a rectangular shape having a pair of long sides and a pair of short sides in a plan view (viewed from the Z direction). In the present embodiment, the long side direction of each main surface 12a, 12b coincides with the X direction. The short side direction of each main surface 12a, 12b corresponds to the Y direction.

The length of the vibrating member 12 in the X direction is, for example, 30 mm. The length of the vibrating member 12 in the Y direction is, for example, 15 mm. The length of the vibrating member 12 in the Z direction is, for example, 100 μm.

The piezoelectric element 10 has a piezoelectric element body 11 and a plurality of external electrodes 13 and 15. In the present embodiment, the piezoelectric element 10 has two external electrodes 13 and 15. The external electrodes 13 and 15 have different polarities.

The piezoelectric body 11 has a rectangular parallelepiped shape. The rectangular parallelepiped shape includes, for example, a rectangular parallelepiped shape with chamfered corners and ridges, and a rectangular parallelepiped shape with rounded corners and ridges. The piezoelectric body 11 has a pair of main surfaces 11a and 11b (first main surface, second main surface) and a side surface 11e. The pair of main surfaces 11a and 11b face each other in the Z direction. That is, the facing direction of the pair of main surfaces 11a and 11b is the Z direction. The facing direction of the pair of principal surfaces 11a and 11b is also an orthogonal direction orthogonal to each of the pair of principal surfaces 11a and 11b.

The side surface 11e is adjacent to each of the pair of main surfaces 11a and 11b. The pair of main surfaces 11a and 11b extend in the facing direction. In the present embodiment, the piezoelectric body 11 has four side surfaces 11e. Each side surface 11e connects the main surface 11a and the main surface 11b to each other. The main surface 11b faces the main surface 12a in the Z direction. The main surface 11b is joined (bonded) to the central portion of the main surface 12a by an adhesive layer 61.

Each main surface 11a, 11b has a rectangular shape. Each main surface 11a, 11b has a rectangular shape having a pair of long sides 11c and a pair of short sides 11d. That is, the piezoelectric element 10 (piezoelectric element body 11) has a rectangular shape having a pair of long sides and a pair of short sides in a plan view (viewed from the Z direction). In the present embodiment, the long side direction of each main surface 11a, 11b coincides with the X direction. The short side direction of each of the main surfaces 11a and 11b coincides with the Y direction.

The length of the piezoelectric body 11 in the X direction is, for example, 20 mm. The length of the piezoelectric body 11 in the Y direction is, for example, 10 mm. The length of the piezoelectric body 11 in the Z direction is, for example, 200 μm.

FIG. 5 is an exploded perspective view showing the configuration of the piezoelectric element. As shown in FIGS. 4 and 5, the piezoelectric element body 11 is configured by laminating a plurality of piezoelectric body layers 17a, 17b, 17c, 17d. That is, the piezoelectric body 11 has a plurality of stacked piezoelectric layers 17a, 17b, 17c, 17d. In the present embodiment, the piezoelectric body 11 has four piezoelectric layers 17a, 17b, 17c and 17d. In the piezoelectric body 11, the direction in which the plurality of piezoelectric layers 17a, 17b, 17c, 17d are stacked coincides with the Z direction. The piezoelectric layer 17a has a main surface 11a. The piezoelectric layer 17d has a main surface 11b. The piezoelectric layers 17b and 17c are located between the piezoelectric layers 17a and 17d.

Each piezoelectric layer 17a, 17b, 17c, 17d is made of a piezoelectric material. In the present embodiment, each piezoelectric layer 17a, 17b, 17c, 17d is made of a piezoelectric ceramic material. Examples of the piezoelectric ceramic material include PZT [Pb(Zr,Ti)O ₃ ], PT(PbTiO ₃ ), PLZT[(Pb,La)(Zr,Ti)O ₃ ], or barium titanate (BaTiO ₃ ). Is used. Each of the piezoelectric layers 17a, 17b, 17c, 17d is made of, for example, a sintered body of a ceramic green sheet containing the above-mentioned piezoelectric ceramic material. In the actual piezoelectric element 11, the piezoelectric layers 17a, 17b, 17c, 17d are integrated so that the boundaries between the piezoelectric layers 17a, 17b, 17c, 17d cannot be recognized.

The piezoelectric element 10 includes a plurality of internal electrodes 19, 21, 23 arranged in the piezoelectric body 11. In the present embodiment, the piezoelectric element 10 includes three internal electrodes 19, 21, 23. Each internal electrode 19, 21, 23 is made of a conductive material. For the conductive material, for example, Ag, Pd, or Ag-Pd alloy is used. Each of the internal electrodes 19, 21 and 23 is formed, for example, as a sintered body of a conductive paste containing the above conductive material. In the present embodiment, the outer shape of each internal electrode 19, 21, 23 is rectangular.

The internal electrodes 19, 21, 23 are arranged at different positions (layers) in the Z direction. The internal electrode 19 and the internal electrode 21 face each other with a space in the Z direction. The internal electrode 21 and the internal electrode 23 face each other with a space in the Z direction. The internal electrode 19 is located between the piezoelectric layer 17a and the piezoelectric layer 17b. The internal electrode 21 is located between the piezoelectric layer 17b and the piezoelectric layer 17c. The internal electrode 23 is located between the piezoelectric layer 17c and the piezoelectric layer 17d. The internal electrodes 19, 21, 23 are not exposed on the surface of the piezoelectric body 11. That is, the internal electrodes 19, 21, 23 are not exposed on the side surfaces 11e. The internal electrodes 19, 21, 23 are separated from all the edges (four sides) of the main surfaces 11a, 11b when viewed from the Z direction.

The plurality of external electrodes 13 and 15 are arranged on the main surface 11a. The external electrode 13 and the external electrode 15 are arranged in the X direction. The external electrode 13 and the external electrode 15 are adjacent to each other in the X direction. The plurality of external electrodes 13 and 15 are arranged at the center of the main surface 11a. The plurality of external electrodes 13 and 15 are separated from all the edges (four sides) of the main surface 11a when viewed in the Z direction. Each of the external electrodes 13 and 15 has a rectangular shape when viewed from the Z direction. Each external electrode 13, 15 is made of a conductive material. For the conductive material, for example, Ag, Pd, or Ag-Pd alloy is used. Each of the external electrodes 13 and 15 is formed, for example, as a sintered body of a conductive paste containing the above conductive material.

The external electrode 13 is electrically connected to the connection conductor 25 through the via conductor 31. The connection conductor 25 is located in the same layer as the internal electrode 19. The connection conductor 25 is located inside the internal electrode 19. An opening is formed in the internal electrode 19 at a position corresponding to the external electrode 13 when viewed from the Z direction. The connection conductor 25 is located in the opening formed in the internal electrode 19. When viewed from the Z direction, the entire edges of the connection conductor 25 are surrounded by the internal electrode 19.

The connection conductor 25 is located between the piezoelectric layer 17a and the piezoelectric layer 17b. The internal electrode 19 and the connection conductor 25 are separated from each other. The connection conductor 25 faces the external electrode 13 in the Z direction. The via conductor 31 is connected to the external electrode 13 and the connection conductor 25. The connection conductor 25 is electrically connected to the internal electrode 21 through the via conductor 33. The connection conductor 25 faces the internal electrode 21 in the Z direction. The via conductor 33 is connected to the connection conductor 25 and the internal electrode 21.

The internal electrode 21 is electrically connected to the connection conductor 27 through the via conductor 35. The connection conductor 27 is located in the same layer as the internal electrode 23. The connection conductor 27 is located inside the internal electrode 23. An opening is formed in the internal electrode 23 at a position corresponding to the external electrode 13 (connection conductor 25) when viewed from the Z direction. The connection conductor 27 is located in the opening formed in the internal electrode 23. When viewed from the Z direction, the entire edges of the connection conductor 27 are surrounded by the internal electrode 23.

The external electrode 15 is electrically connected to the internal electrode 19 through the via conductor 37. The internal electrode 19 faces the external electrode 15 in the Z direction. The via conductor 37 is connected to the external electrode 15 and the internal electrode 19.

The internal electrode 19 is electrically connected to the connection conductor 29 through the via conductor 39. The connection conductor 29 is located in the same layer as the internal electrode 21. The connection conductor 29 is located inside the internal electrode 21. An opening is formed in the internal electrode 21 at a position corresponding to the external electrode 15 when viewed from the Z direction. The connection conductor 29 is located in the opening formed in the internal electrode 21. When viewed from the Z direction, the entire edges of the connection conductor 29 are surrounded by the internal electrode 21.

The connection conductor 29 is located between the piezoelectric layers 17b and 17c. The internal electrode 21 and the connection conductor 29 are separated from each other. The connection conductor 29 faces the internal electrode 19 in the Z direction. The via conductor 39 is connected to the internal electrode 19 and the connection conductor 29. The connection conductor 29 is electrically connected to the internal electrode 23 through the via conductor 41. The connection conductor 29 faces the internal electrode 23 in the Z direction. The via conductor 41 is connected to the connection conductor 29 and also to the internal electrode 23.

The external electrode 13 is electrically connected to the internal electrode 21 through the via conductor 31, the connection conductor 25, and the via conductor 33. The external electrode 15 is electrically connected to the internal electrode 19 through the via conductor 37. The external electrode 15 is electrically connected to the internal electrode 23 through the via conductor 37, the internal electrode 19, the via conductor 39, the connection conductor 29, and the via conductor 41.

The connection conductors 25, 27, 29 and the via conductors 31, 33, 35, 37, 39, 41 are made of a conductive material. Each of the via conductors 31, 33, 35, 37, 39, 41 is a via conductor group including a plurality of via conductors, but may be a single via conductor. The via conductors 31 and 33 arranged in the piezoelectric layers 17a and 17b adjacent to each other in the Z direction are arranged so as to be separated from each other when viewed in the Z direction and do not overlap. The via conductors 37 and 39 arranged on the piezoelectric layers 17a and 17b are arranged so as to be separated from each other when viewed from the Z direction and do not overlap. The via conductors 33 and 35 arranged in the piezoelectric layers 17b and 17c adjacent to each other in the Z direction are arranged so as to be separated from each other when viewed from the Z direction and do not overlap. The via conductors 39 and 41 arranged on the piezoelectric layers 17b and 17c are arranged so as to be separated from each other and not to overlap with each other when viewed from the Z direction.

For the conductive material, for example, Ag, Pd, or Ag-Pd alloy is used. The connection conductors 25, 27, 29 and the via conductors 31, 33, 35, 37, 39, 41 are formed, for example, as a sintered body of a conductive paste containing the conductive material. The connection conductors 25, 27, 29 have a rectangular shape. For the via conductors 31, 33, 35, 37, 39, 41, the conductive paste filled in the through holes formed in the ceramic green sheets for forming the corresponding piezoelectric layers 17a, 17b, 17c is sintered. It is formed by

Neither conductors electrically connected to the internal electrodes 19 and 23 nor conductors electrically connected to the internal electrodes 21 are arranged on the main surface 11b of the piezoelectric body 11. In the present embodiment, when the main surface 11b is viewed from the Z direction, the entire main surface 11b is exposed. The main surfaces 11a and 11b are natural surfaces. The natural surface is a surface formed by the surface of crystal grains grown by firing.

Neither conductors electrically connected to the internal electrodes 19 and 23 nor conductors electrically connected to the internal electrodes 21 are arranged on each side surface 11e of the piezoelectric body 11. In the present embodiment, when each side surface 11e of the piezoelectric element body 11 is viewed from the X direction and the Y direction, the entire side surface 11e except the part covered by the side surface portion 71a of the insulating joining member 71 described later. Exposed. In the present embodiment, each of these side surfaces 11e is also a natural surface.

A region of the piezoelectric layer 17b sandwiched by the internal electrodes 19 and 21 and a region of the piezoelectric layer 17c sandwiched by the internal electrodes 21 and 23 constitute a piezoelectrically active region. .. In the present embodiment, the piezoelectrically active region is located so as to surround the plurality of external electrodes 13 and 15 when viewed from the Z direction. When viewed from the Z direction, the piezoelectric element body 11 includes a piezoelectrically active region in a region located between the external electrode 13 and the external electrode 15. When viewed in the Z direction, the piezoelectric body 11 also includes a piezoelectrically active region outside the region where the external electrodes 13 and 15 are located.

As shown in FIGS. 1 to 4, the connection structure 2 has a strip-shaped wiring member 50 connected to the vibrating section 1 and a plurality of lead wires 80 connected to the wiring member 50. .. In the present embodiment, the connection structure 2 has two lead wires 80.

FIG. 6 is a top view of the connection structure and the piezoelectric element. As shown in FIGS. 1 to 6, the wiring member 50 extends along the long side 11c of the main surface 11a when viewed from the facing direction (Z direction) of the main surfaces 11a and 11b, and the main surface 11a. Intersects the short side 11d. In the present embodiment, the wiring member 50 is arranged so as to be orthogonal to the short side 11d of the main surface 11a. The direction in which the wiring member 50 extends is orthogonal to the Y direction. The wiring member 50 extends in the X direction. The wiring member 50 has one end that is electrically and physically connected to the piezoelectric element 10 and the other end that is electrically and physically connected to the lead wire 80.

The vibration device 100 includes a joining member 70, a joining member 71, and a joining member 72. The wiring member 50 is joined (bonded) to the vibrating portion 1 by the joining member 70 and the joining member 71. The wiring member 50 is joined (bonded) to the case 3 by the joining member 72. The joining member 70, the joining member 71, and the joining member 72 are arranged apart from each other.

The joining member 70 is a resin layer containing a plurality of conductive particles (not shown) and has conductivity. The conductive particles are, for example, metal particles and gold plated particles. The joining member 70 contains, for example, a thermosetting elastomer. The joining member 70 is formed, for example, by curing an anisotropic conductive paste or an anisotropic conductive film. The joining member 71 does not contain conductive particles and has electrical insulation. The joining member 71 contains, for example, nitrile rubber. The joining member 71 may include the same resin material as the resin material included in the joining member 70. The joining member 72 does not contain conductive particles and has electrical insulation. The joining member 72 is made of, for example, an epoxy resin or an acrylic resin.

The wiring member 50 has a first region R1, a second region R2, a third region R3, a fourth region R4, and a fifth region R5.

The first region R1 faces the main surface 11a in the Z direction. The first region R1 is located on the plurality of external electrodes 13 and 15. The first region R1 integrally covers the plurality of external electrodes 13 and 15. The plurality of external electrodes 13 and 15 are not exposed from the first region R1 when viewed in the Z direction. The first region R1 is joined to the plurality of external electrodes 13 and 15 and the main surface 11a by the joining member 70. The joining member 70 is provided between the first region R1 and the piezoelectric element 10 so as to integrally cover the plurality of external electrodes 13 and 15 when viewed from the Z direction. The first region R1 is supported by the piezoelectric element 10.

In the present embodiment, the first region R1 has a rectangular shape when viewed from the Z direction. The long side direction of the first region R1 is the X direction and coincides with the long side direction of the main surface 11a. When viewed from the Z direction, the short side direction of the first region R1 is the Y direction and coincides with the short side direction of the main surface 11a. The length of the first region R1 in the Y direction is shorter than the length of the wiring member 50 in the Y direction.

The second region R2 faces the main surface 11a in the Z direction. The second region R2 is separated from the first region R1 in the X direction. The second region R2 is joined to the main surface 11a by the joining member 71. The joining member 71 joins the entire width direction (Y direction) of the wiring member 50 to the main surface 11a. The second region R2 is joined to one end 11f in the long side direction of the main surface 11a. The second region R2 is supported by the piezoelectric element 10.

The length of the second region R2 in the Y direction is equal to the width of the wiring member 50 (the length of the wiring member 50 in the Y direction). The joining member 71 is provided along one short side 11d of the main surface 11a. The joining member 71 has a main surface portion provided on the main surface 11a (specifically, the end portion 11f) and a side surface portion 71a provided on the side surface 11e. The side surface portion 71a is provided at the end of the side surface 11e on the main surface 11a side.

The distance between the second region R2 and the main surface 11a in the Z direction gradually increases as the second region R2 moves away from the third region R3. The maximum value of the distance between the principal surface 11a and the second region R2 in the Z direction is larger than the maximum value of the distance between the principal surface 11a and the first region R1 in the Z direction.

The third region R3 is located between the first region R1 and the second region R2, and connects the first region R1 and the second region R2 to each other. The third region R3 is adjacent to each of the first region R1 and the second region R2. The third region R3 is separated from the main surface 11a. The third region R3 is not joined to the piezoelectric element 10. The Y-direction length of the third region R3 matches the Y-direction length of the first region R1.

The first region R1, the second region R2, and the third region R3 overlap the main surface 11a when viewed from the Z direction. The region of the wiring member 50 that overlaps the main surface 11a when viewed from the Z direction includes a first region R1, a second region R2, and a third region R3.

The fourth region R4 is supported by the supporting portion 3f. The fourth region R4 overlaps with the support portion 3f when viewed from the Z direction. The fourth region R4 is joined (bonded) to the support portion 3f by the joining member 72. The fourth region R4 is fixed to the support portion 3f. The joining member 72 is provided on the surface of the cover 57 in the fourth region R4.

The fifth region R5 is located between the second region R2 and the fourth region R4, and connects the second region R2 and the fourth region R4 to each other. The fifth region R5 is adjacent to each of the second region R2 and the fourth region R4. The fifth region R5 does not overlap the supporting portion 3f and the main surface 11a when viewed from the Z direction. The fifth region R5 is curved.

The distance L1 between the first region R1 and the second region R2 in the X direction is shorter than the distance L2 between the second region R2 and the fourth region R4 in the X direction. The interval L1 is equal to the length of the third region R3 in the X direction. The distance L2 is equal to the length of the fifth region R5 in the X direction.

FIG. 6 is a top view of the connection structure and the piezoelectric element. FIG. 7 is a bottom view of the connection structure. As shown in FIGS. 1 to 7, the wiring member 50 includes a base 51, a plurality of conductor layers 53 and 55, a cover 57, and a reinforcing member 59. In this embodiment, the wiring member 50 includes two conductor layers 53 and 55. The wiring member 50 is, for example, a flexible printed circuit board (FPC) or a flexible flat cable (FFC).

The base 51 has a strip shape and has a pair of main surfaces 51a and 51b facing each other. The base 51 has electrical insulation. The base 51 is, for example, a resin layer made of a resin such as a polyimide resin. The base 51 has a thickness of 100 μm, for example.

The conductor layers 53 and 55 are arranged on the main surface 51 a of the base 51. The conductor layers 53 and 55 are joined (bonded) to the main surface 51a by an adhesive layer (not shown). Each conductor layer 53, 55 is made of Cu, for example. Each of the conductor layers 53 and 55 may have, for example, a structure in which a Ni plating layer and an Au plating layer are provided in this order on a Cu layer. The conductor layer 53 and the conductor layer 55 are arranged apart from each other. The thickness of each conductor layer 53, 55 is, for example, 20 μm.

The conductor layer 53 includes an end portion 53a connected to the lead wire 80, an end portion 53b connected to the external electrode 13, and a connection portion 53c connecting the end portion 53a and the end portion 53b. There is. The connection portion 53c extends in the direction in which the wiring member 50 extends (X direction). The end portion 53a is adjacent to one end portion of the connecting portion 53c in the direction in which the wiring member 50 extends. The end portion 53b is adjacent to the other end portion of the connecting portion 53c in the width direction (Y direction) of the wiring member 50.

The conductor layer 55 includes an end 55a connected to the lead wire 80, an end 55b connected to the external electrode 15, and a connecting part 55c connecting the end 55a and the end 55b. There is. The connecting portion 55c extends in the direction in which the wiring member 50 extends (X direction). The end 55a is adjacent to one end of the connecting portion 55c in the direction in which the wiring member 50 extends. The end portion 55b is adjacent to the other end portion of the connecting portion 55c in the width direction (Y direction) of the wiring member 50.

The end portion 53a and the end portion 55a are arranged apart from each other in the width direction of the wiring member 50. The end portion 53b and the end portion 55b are arranged apart from each other in the extending direction of the wiring member 50. The connection portion 53c and the connection portion 55c are arranged parallel to each other and separated from each other in the width direction of the wiring member 50.

The joining member 70 exists between the end portion 53 a and the external electrode 13. The end 53a and the external electrode 13 are electrically connected to each other through the conductive particles included in the joining member 70. The joining member 70 exists between the end 55 a and the external electrode 15. The end 55a and the external electrode 15 are electrically connected to each other through the conductive particles included in the joining member 70.

The cover 57 is arranged on the main surface 51a, as particularly shown in FIG. The cover 57 covers the conductor layers 53 and 55 and the main surface 51a. The cover 57 is joined (bonded) to the conductor layers 53, 55 and an area of the main surface 51a exposed from the conductor layers 53, 55 with an adhesive layer (not shown). The cover 57 is, for example, a resin layer made of a resin such as a polyimide resin. The cover 57 has a thickness of 25 μm, for example.

The ends 53a and 53b of the conductor layer 53, the ends 55a and 55b of the conductor layer 55, and a part of the main surface 51a are exposed from the cover 57. A partial region of the main surface 51a is a region arranged between the end portions 53a and 55a and a region arranged between the end portions 53b and 55b when viewed from the Z direction. .. Each of the end portions 53a, 53b, 55a, 55b is plated with nickel and gold flash, for example.

The reinforcing member 59 is arranged at the other end of the wiring member 50. The reinforcing member 59 is arranged on the main surface 51b of the base 51. The reinforcing member 59 is joined (bonded) to the main surface 51b by an adhesive layer (not shown). The reinforcing member 59 is a rectangular plate-shaped member having electrical insulation. The reinforcing member 59 is made of, for example, a polyimide resin.

The lead wire 80 includes a bundle 81 of a plurality of core wires and a covering member 82 that covers the bundle 81. In the present embodiment, the lead wire 80 has twelve core wires. The covering member 82 covers the outer circumference of the bundle 81. The covering member 82 collectively covers the plurality of core wires. The ends of the bundle 81 are exposed from the covering member 82 and are connected to the ends 53a and 55a of the conductor layers 53 and 55, respectively. The ends of the bundle 81 are connected to the ends 53a and 55a by a conductive adhesive. The conductive adhesive is, for example, a hot-melt metal such as solder. The conductive adhesive may be formed using a conductive paste containing Au, Cu or the like as a conductive material.

In an electronic device including the vibrating device 100, a sound is generated by vibrating the piezoelectric element 10. Vibration of the piezoelectric element 10 may generate a tactile sensation as well as a sound.

As described above, the wiring member 50 has the second region R2 joined to the main surface 11a of the piezoelectric body 11 in addition to the first region R1 joined to the external electrodes 13 and 15. .. Therefore, even if the vibrating device 100 vibrates, it is difficult for a mechanical load to act on the joint between the first region R1 and the external electrodes 13 and 15. Therefore, peeling between the first region R1 and the external electrodes 13 and 15 is unlikely to occur.

Further, the wiring member 50 has a third region R3 located between the first region R1 and the second region R2 and separated from the main surface 11a of the piezoelectric element body 11. Therefore, even when the first region R1 and the external electrodes 13 and 15 are joined by the conductive joining member 70 and the second region R2 and the main surface 11a of the piezoelectric element body 11 are joined by the insulating joining member 71. The third region R3 secures a gap between the joining member 70 and the joining member 71. That is, the joining member 70 and the joining member 71 can be kept in a state of being separated from each other. This suppresses the joining member 71 from pushing the joining member 70 and entering between the first region R1 and the external electrodes 13 and 15 to cause poor conduction between the wiring member 50 and the external electrodes 13 and 15. It

From the above, in the vibration device 100, the electrical connection between the external electrodes 13 and 15 and the wiring member 50 is secured. Therefore, the electrical reliability of the vibrating device 100 does not easily deteriorate.

The main surface 11a has a rectangular shape. Therefore, the amount of displacement of the piezoelectric body 11 is greatest at the center of the major surface 11a in the long side direction (X direction), and is smallest at both ends of the major surface 11a in the long side direction, that is, the short sides 11d. When viewed from the Z direction, the wiring member 50 extends along the long side 11c of the main surface 11a and intersects the short side 11d of the main surface 11a. The second region R2 is joined to one end 11f in the long side direction of the main surface 11a. Therefore, the displacement amount of the second region R2 is smaller than that in the case where the second region R2 is joined to the end of the main surface 11a in the short side direction (Y direction), that is, the long side 11c.

Since the second region R2 is supported by the piezoelectric element 10, it is displaced along with the displacement of the piezoelectric element 10. In the wiring member 50, since the fifth region R5 is connected to the second region R2, the fifth region R5 tends to be displaced along with the displacement of the second region R2. However, the fifth region R5 is also connected to the fourth region R4. Since the fourth region R4 is supported by the support portion 3f, it does not displace. Therefore, the vibration of the fifth region R5 does not match the vibration of the piezoelectric element 10 and may hinder the vibration of the piezoelectric element 10. In the vibrating device 100, since the displacement amount of the second region R2 is relatively small, the displacement of the fifth region R5 connected to the second region R2 is suppressed. Therefore, the vibration of the piezoelectric element 10 is less likely to be disturbed, and the amplitude of the piezoelectric element 10 can be increased.

The distance L1 between the first region R1 and the second region R2 in the X direction is shorter than the distance L2 between the second region R2 and the fourth region R4 in the X direction. In this case, the third region R3 easily deforms following the vibration of the piezoelectric element 10, and the strain of the wiring member 50 can be concentrated in the play of the fifth region R5. In this way, the fifth region R5 easily functions effectively, so that the amplitude of the piezoelectric element 10 can be increased.

The bottom portion 3a of the case 3 holds both end portions 1a of the vibrating portion 1 in the X direction. Therefore, the amplitude in the central portion of the vibrating portion 1 in the X direction can be further increased.

The distance between the second region R2 and the main surface 11a in the Z direction gradually increases as the second region R2 moves away from the third region R3. Therefore, as compared with the case where the distance between the second region R2 and the main surface 11a is the same as the distance between the third region R3 and the main surface 11a and is constant, the distance between the second region R2 and the main surface 11a is large. The volume of the joining member 71 provided can be increased. Thereby, in the wiring member 50, the vibration of the fifth region R5 is easily absorbed. Therefore, the vibration of the piezoelectric element 10 is less likely to be disturbed, and the amplitude of the piezoelectric element 10 can be further increased. For example, it is conceivable to provide a stepped portion in the third region R3 and increase the distance between the second region R2 and the main surface 11a, but in this case, the mechanical load tends to concentrate on the stepped portion. On the other hand, in the vibration device 100, since the second region R2 is gradually separated from the main surface 11a, it is not necessary to provide the wiring member 50 with a stepped portion.

The joining member 71 has a side surface portion 71a provided on the side surface 11e. Since the bonding member 71 is provided not only on the main surface 11a but also on the side surface 11e, the bonding strength between the second region R2 and the piezoelectric element body 11 is improved. As a result, even when the vibrating device 100 vibrates, a mechanical load is less likely to act on the joint between the first region R1 and the external electrodes 13 and 15. Therefore, the peeling between the first region R1 and the external electrodes 13 and 15 is further unlikely to occur. Further, since the joining member 71 has an insulating property, the occurrence of a short circuit is suppressed.

The maximum value of the distance between the main surface 11a and the second region R2 in the Z direction is larger than the maximum value of the distance between the main surface 11a and the first region R1 in the X direction. Therefore, the wiring member 50 is easily deformed smoothly, and the amplitude of the piezoelectric element 10 can be more effectively increased.

The vibrating section 1 has a vibrating member 12 to which the piezoelectric element 10 is joined. Therefore, the vibration of the piezoelectric element 10 can be increased.

The external electrodes 13 and 15 are arranged at the center of the main surface 11a. Therefore, the piezoelectric element 10 can be vibrated in a well-balanced manner.

The electronic device according to the present embodiment includes the vibrating device 100, and thus electrical reliability is unlikely to deteriorate.

The present invention is not necessarily limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention.

FIG. 8 is a partially enlarged cross-sectional view of a vibrating device according to a modification. As shown in FIG. 8, in the vibration device 100A according to the modification, the case 3 is not provided with the recess 3d, and the entire main surface 12b of the vibration member 12 is bonded (bonded) to the bottom 3a by the adhesive layer 60. This is different from the vibrating device 100. Even in this case, the electrical connection between the external electrodes 13 and 15 and the wiring member 50 is ensured. Therefore, the electrical reliability of the vibrating device 100A does not easily deteriorate.

In the vibrating devices 100 and 100A, the vibrating section 1 includes the vibrating member 12, but the vibrating section 1 may not include the vibrating member 12. In this case, the structure of the vibrating portion 1 can be simplified.

1... Vibration part, 1a... End part, 3a... Bottom part (holding part), 10... Piezoelectric element, 11... Piezoelectric element, 11a... Main surface (first main surface), 11b... Main surface (second main surface) , 11c...long side, 11d...short side, 11e...side surface, 11f...end, 12...vibrating member, 13,15...external electrode, 19,21,23...internal electrode, 50...wiring member, 71...joining member , 71a... Side portion, 100, 100A... Vibrating device, R1... First area, R2... Second area, R3... Third area, R4... Fourth area, R5... Fifth area.

Claims (10)

A vibrating section having a piezoelectric element,
A wiring member electrically connected to the piezoelectric element,
The piezoelectric element includes a piezoelectric element body, an internal electrode arranged inside the piezoelectric element body, and an external electrode electrically connected to the internal electrode,
The piezoelectric element is adjacent to the first main surface and the second main surface facing each other, the first main surface and the second main surface, respectively, the first main surface and the second main surface And a side surface extending in the opposite direction of,
The external electrode is disposed on the first main surface,
The wiring member is
A first region located on the external electrode and joined to the external electrode;
A second region joined to the first main surface,
A vibrating device, comprising: a third region located between the first region and the second region and spaced from the first main surface. The first main surface has a rectangular shape,
When viewed from the facing direction, the wiring member extends along a long side of the first main surface and intersects with a short side of the first main surface,
The vibrating device according to claim 1, wherein the second region is joined to one end of the first main surface in the long side direction. The wiring member further has a fourth region supported by a supporting portion, and a fifth region located between the second region and the fourth region,
The vibrating device according to claim 2, wherein a distance between the first region and the second region in the long side direction is shorter than a distance between the second region and the fourth region in the long side direction. The vibrating device according to claim 2, further comprising holding portions that hold both end portions of the vibrating portion in a long side direction of the first main surface. The space|interval of the said 2nd area|region and the said 1st main surface in the said opposing direction becomes large gradually, so that the said 2nd area|region separates from the said 3rd area|region. Vibrating device. Further comprising a joining member that joins the second region to the first main surface,
The vibrating device according to claim 1, wherein the joining member has a side surface portion provided on the side surface. The maximum value of the distance between the first main surface and the second region in the facing direction is larger than the maximum value of the distance between the first main surface and the first region in the facing direction. The vibrating device according to any one of 1. The vibrating device according to claim 1, wherein the vibrating unit further includes a vibrating member to which the piezoelectric element is joined. The vibrating device according to claim 1, wherein the external electrode is arranged in a central portion of the first main surface. An electronic apparatus comprising the vibrating device according to claim 1.