Vibrating devices

Abstract

The vibration device (1) includes: a piezoelectric part (2) containing a piezoelectric element (5), a frame (3) holding the piezoelectric part (2), a wiring component (4) electrically connected to the piezoelectric part (2), and a connecting component (P) for connecting the frame (3) to an external device. The frame (3) has a bottom part (11) on which the piezoelectric part (2) is fixed, and a side part (12) erected on the edge of the bottom part (11). The side part (12) has a first surface (F1) formed on the top (12a) of the side part (12) and a second surface (F2) that descends one level from the first surface (F1) through a cutout (33) formed on the top (12a). The connecting component (P) extends along the first surface (F1) in a manner that is mounted on the cutout (33). The wiring component (4) is connected to the connecting component (P) at the position of the first surface (F1) and passes through the cutout (33) in a state of non-connection with the second surface (F2).

Description

Technical Field

[0001] This invention relates to vibration devices. Background Technology

[0002] As an existing vibration device, for example, there is a sound generator described in Japanese Patent Application Publication No. 2017-017426. This existing sound generator includes: a piezoelectric element having a surface electrode, a vibrating body on which the piezoelectric element is mounted, a frame supporting the vibrating body, and a wiring component with one end connected to the surface electrode and the other end fixed to the frame. The width of the other end of the wiring component is wider than the width of the other parts.

[0003] In such vibrating devices, achieving the desired acoustic characteristics through the vibration of the frame becomes a key feature. To obtain these desired acoustic characteristics, stabilizing the chamber characteristics within the frame when the vibrating device is mounted on an external device becomes important. Since wiring components electrically connected to the piezoelectric element exist within the frame, it is considered necessary to find a way to ensure that these wiring components do not affect the chamber design accuracy when the vibrating device is mounted on an external device. Summary of the Invention

[0004] This invention was made to solve the above-mentioned technical problems, and its purpose is to provide a vibration device that improves acoustic characteristics.

[0005] A vibration device according to one aspect of the present invention comprises: a piezoelectric part including a piezoelectric element; a frame holding the piezoelectric part; a wiring member electrically connected to the piezoelectric part; and a connecting member connecting the frame to an external device. The frame has a bottom part on which the piezoelectric part is fixed and a side part erected on the edge of the bottom part. The side part has a first surface formed at the top of the side part and a second surface descending one level from the first surface through a cutout formed at the top. The connecting member extends along the first surface in a manner that it is mounted on the cutout. The wiring member engages with the connecting member at the position of the first surface and passes through the cutout in a state that is not engaged with the second surface.

[0006] In this vibrating device, a connecting member for joining the frame to an external device is disposed on the top first surface of the side portion. This ensures stable installation of the vibrating device to the external device. Furthermore, in this vibrating device, the wiring component engages with the connecting member mounted on the cutout at the top of the side portion on the first surface, while the second surface, one level below the first surface, remains unengaged. By engaging the wiring component with the connecting member on the first surface, wobbling of the wiring component around the piezoelectric element is prevented, avoiding any impact on the accuracy of the cavity design. Additionally, since the wiring component is unengaged on the second surface, even if dimensional errors occur at the cutout or other locations, the flatness of the connecting member on the first surface is maintained, preserving the stability of the vibrating device's installation. Therefore, in this vibrating device, the cavity characteristics around the piezoelectric element can be easily ensured, resulting in improved acoustic characteristics.

[0007] Alternatively, the connecting component may be connected to at least a portion of the second surface. In this case, by connecting the wiring component to both the first and second surfaces, it is possible to more reliably prevent the wiring component from wobbling around the piezoelectric part.

[0008] Alternatively, the joint area between the wiring component and the connecting component may be larger than the joint area between the second surface and the connecting component. In this case, over-joining between the second surface and the connecting component can be avoided, and the flatness of the connecting component on the first surface can be maintained.

[0009] Alternatively, tension can be applied to the wiring components along their extension direction between the piezoelectric part and the cutout part. This suppresses collision noise caused by interference between the wiring components and the frame, even when vibration is applied to the frame. Therefore, the effects of vibration on the chamber characteristics can be avoided.

[0010] Alternatively, the side and bottom portions can be smoothly continuous, and the side portion can be inclined outwards towards the edge relative to the bottom portion. In this case, vibration is effectively transmitted from the bottom portion, where the piezoelectric element is located, to the side portion, and the vibration of the side portion and the vibration of the bottom portion can be fully extracted as output together. Therefore, further improvement in acoustic characteristics can be achieved. Attached Figure Description

[0011] Figure 1 This is a perspective view showing one embodiment of the vibration device of the present invention.

[0012] Figure 2 yes Figure 1 The top view of the vibrating device shown.

[0013] Figure 3 yes Figure 1 The front view of the vibrating device shown.

[0014] Figure 4 yes Figure 1 The cross-sectional view of line IV-IV in the diagram.

[0015] Figure 5 yes Figure 1 The V-V line cross-section diagram.

[0016] Figure 6 This is a schematic cross-sectional view showing another configuration example of the joining components. Detailed Implementation

[0017] Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the vibration device of one aspect of the present invention will be described in detail.

[0018] Figure 1 This is a perspective view illustrating one embodiment of the vibration device of the present invention. The vibration device 1 is used as an audio device, such as a loudspeaker or buzzer. Figure 1 As shown, the vibration device 1 is configured to include a piezoelectric part 2, a frame 3, and a wiring component 4.

[0019] The piezoelectric part 2 is configured to include a piezoelectric element 5. The piezoelectric element 5 has a piezoelectric body and a pair of external electrodes. The piezoelectric element 5 is formed into a flat cuboid shape in the thickness direction. The cuboid shape may also include a shape with chamfered corners and edges, or a shape with rounded corners and edges. The piezoelectric body is composed of a stack of multiple piezoelectric body layers. Each piezoelectric body layer is formed of a piezoelectric material such as piezoelectric ceramic. Examples of piezoelectric ceramic materials include, for example, PZT[Pb(Zr,Ti)O3], PT(PbTiO3), PLZT[(Pb,La)(Zr,Ti)O3], or barium titanate (BaTiO3).

[0020] Each piezoelectric layer is, for example, a sintered body of a ceramic green sheet containing the aforementioned piezoelectric ceramic. In a practical piezoelectric body, each piezoelectric layer is integrated to the point that the boundaries between the piezoelectric layers are indistinguishable. Multiple internal electrodes (not shown) are disposed within the piezoelectric body. Each internal electrode is formed of a conductive material. Examples of conductive materials include Ag, Pd, and Ag-Pd alloys.

[0021] The piezoelectric part 2 can also be a component in which a vibrating plate is combined with the piezoelectric element 5. The vibrating plate is, for example, a plate-shaped component made of a metal material. Examples of metal materials that make up the vibrating plate include, for example, Ni-Fe alloy, Ni, brass, stainless steel, etc. The vibrating plate is, for example, rectangular. The vibrating plate is disposed on the bottom surface (the surface on the side of the frame 3) of the piezoelectric element 5 and can be fixed to the piezoelectric element 5 and the frame 3 using, for example, adhesive materials, double-sided tape, etc.

[0022] The frame 3 is a component that holds the piezoelectric part 2. The frame 3 is formed, for example, by stamping metal. Examples of metal materials constituting the frame 3 include stainless steel, aluminum, and 42Ni alloy. The frame 3 has a bottom portion 11 and multiple side portions 12. The bottom portion 11 is the portion on which the piezoelectric part 2 is fixed. Here, the side portions 12 are erected such that they surround the piezoelectric part 2 at the edge of the bottom portion 11.

[0023] An outwardly extending flange 13 is provided at the top 12a of the side portion 12. The flange 13 extends from the top 12a of the side portion 12 parallel to the bottom portion 11 with a predetermined width. The flange 13 functions as a mounting part for mounting the vibrating device 1 to an external device. Double-sided adhesive tape 41 is attached to one side of the flange 13 (the side opposite to the bottom portion 11).

[0024] Wiring component 4 is a component that electrically connects the piezoelectric part 2 and an external device. Wiring component 4 is, for example, a flexible printed circuit board (FPC). One end of wiring component 4 is electrically connected to a pair of external electrodes of the piezoelectric element 5 on one side 2a of the piezoelectric part 2. The connection between one end of wiring component 4 and the external electrodes of the piezoelectric element 5 can be made, for example, using an anisotropic conductive adhesive material. The other end of wiring component 4 (not shown) is electrically connected to the external device.

[0025] Next, refer to Figure 2 and Figure 3 The structure of the frame 3 and the configuration relationship between the piezoelectric part 2 and the frame 3 will be explained.

[0026] Figure 2 yes Figure 1 The top view of the vibrating device shown. Figure 3 This is a front view. In Figure 2 and Figure 3 For ease of explanation, illustrations of wiring component 4 and the double-sided tape 41 described below are omitted. Figure 3 In the middle, the piezoelectric part 2 is further omitted. For example... Figure 2 and Figure 3 As shown, in this embodiment, the piezoelectric part 2 is rectangular when viewed from above. The planar shape of the piezoelectric part 2 is the planar shape of the piezoelectric element 5 when the piezoelectric part 2 is composed only of the piezoelectric element 5, and the planar shape of the vibrating plate when the piezoelectric part is composed of the piezoelectric element 5 and the vibrating plate.

[0027] The bottom surface 11 of the frame 3 forms a trapezoid when viewed from above. That is, the bottom surface 11 has an upper base 21, a lower base 22, and a pair of hypotenuses 23, 23. Here, as... Figure 2As shown, the planar shape of the bottom surface 11 is an isosceles trapezoid. The lower base 22 of the bottom surface 11 is larger than the upper base 21. That is, the bottom surface 11 expands from the upper base 21 towards the lower base 22. The piezoelectric part 2 is disposed approximately at the center of the bottom surface 11. The bottom surface 11 is the main vibrating part of the frame 3, directly transmitting the vibration of the piezoelectric part 2.

[0028] The upper base 21 and lower base 22 of the bottom surface 11 extend along the long side 24 of the piezoelectric part 2 when viewed from above. The upper base 21 of the bottom surface 11 is shorter than the long side 24 of the piezoelectric part 2, and the lower base 22 of the bottom surface 11 is longer than the long side 24 of the piezoelectric part 2. A certain distance is provided between the lower base 22 of the bottom surface 11 and the long side 24 of the piezoelectric part 2. This distance is, for example, shorter than the short side 25 of the piezoelectric part 2.

[0029] The side portion 12 is provided correspondingly to the upper bottom 21 and a pair of inclined edges 23, 23 of the bottom portion 11. The height of the side portion 12 is greater than the thickness of the piezoelectric portion 2. Thus, the piezoelectric portion 2 disposed on the bottom portion 11 is surrounded by the side portion 12 from three directions other than the lower bottom 22 side. The side portion 12 is smoothly continuous with the bottom portion 11 and is inclined outward relative to the bottom portion 11 in a manner that opens towards the edge. The side portion 12 is a subordinate vibrating part of the frame 3, transmitting the vibration of the piezoelectric portion 2 via the bottom portion 11.

[0030] A first opening 31 is formed on the lower bottom 22 side of the bottom portion 11, thus avoiding the presence of a side portion 12. For example... Figure 3 As shown, the first opening 31 is divided by a bottom portion 11, side portions 12, 12 corresponding to the inclined edges 23, 23 of the bottom portion 11, and an imaginary line connecting one side (the mounting surface facing the external device) of the flange portions 13, 13 on the side portions 12, 12 to each other. When the vibrating device 1 is mounted on the external device, the first opening 31 functions as an outlet for extracting the vibration of the piezoelectric unit 2 to the outside.

[0031] A second opening 32 is formed on the upper bottom 21 side of the bottom portion 11 by cutting a portion of the top 12a of the side portion 12. For example... Figure 3 As shown, the second opening 32 is divided by a cutout 33 formed on the side portion 12 corresponding to the upper bottom 21 of the bottom portion 11, and an imaginary line connecting the tops 12a, 12a of the side portion 12 separated by the cutout 33. The width of the cutout 33 is slightly larger than the width of the wiring component 4. The depth of the cutout 33 from the top 12a of the side portion 12 is the same as or slightly larger than the thickness of the wiring component 4. When the vibrating device 1 is mounted on an external device, the second opening 32 functions as the outlet of the wiring component 4, which is electrically connected to the piezoelectric part 2.

[0032] Next, refer to Figure 1 , Figure 4 and Figure 5 The retaining structure of the wiring component 4 described above will be explained.

[0033] Figure 4 yes Figure 1 The cross-sectional view of line IV-IV in the middle. Figure 5 yes Figure 1 The V-V line cross-sectional diagram in the image. (See also:) Figure 4 and Figure 5 As shown, when holding the wiring component 4, the side portion 12 has a first surface F1 formed on the top 12a of the side portion 12, and a second surface F2 that descends one level from the first surface F1 through the cutout 33 formed on the top 12a.

[0034] In this embodiment, such as Figure 1 As shown, the first surface F1 is divided by the tops 12a of the three side portions 12 corresponding to the upper bottom 21 of the bottom portion 11 and the pair of inclined sides 23, 23, and the three flange portions 13 connected to these tops 12a. When viewed from above, the first surface F1 is divided in three directions surrounding the piezoelectric part 2, except for the location where the cutout 33 is formed. The second surface F2 is divided by the bottom surface 33a of the cutout 33. The second surface F2 is located on the side closer to the bottom portion 11 than the first surface F1, at a distance equal to or slightly greater than the thickness of the wiring component 4. The height of the second surface F2 from the bottom portion 11 is higher than the height of one side 2a of the piezoelectric part 2 from the bottom portion 11.

[0035] A connecting member P for joining the frame 3 to an external device is provided on the first surface F1. Here, the connecting member P is made of double-sided adhesive tape 41. The double-sided adhesive tape 41 is provided across approximately the entire surface of the first surface F1. The double-sided adhesive tape 41 is as follows... Figure 4 As shown, the tape is positioned at the cut portion 33 and is mounted on the cut portion 33. Therefore, the double-sided tape 41 is separated from the second surface F2 at an interval equal to the depth of the cut portion 33. Epoxy adhesives, urethane adhesives, silicone, etc., can also be used as the bonding component P.

[0036] like Figure 4 As shown, the wiring component 4 passes through a cutout 33 between the first surface F1 and the second surface F2. The wiring component 4 is engaged with the double-sided tape 41 at the position of the first surface F1. On the other hand, the wiring component 4 is not engaged with the second surface F2. The wiring component 4 can be in contact with the second surface F2 or in a state separate from the second surface F2.

[0037] The wiring component 4 is connected to one side 2a of the piezoelectric part 2 using an anisotropic conductive adhesive material or the like. Furthermore, the wiring component 4 is bonded to the double-sided tape 41 at the position of the first surface F1 via the cutout 33. Between the piezoelectric part 2 and the cutout 33, the wiring component 4 is arranged at an angle that gradually increases in height towards the cutout 33. Figure 5 As shown, the wiring component 4 is linearly inclined at a certain angle from the edge of the piezoelectric part 2 on the side of the cutout 33 to the edge of the cutout 33 on the side of the piezoelectric part 2. In this state, tension is applied to the wiring component 4 between the piezoelectric part 2 and the cutout 33 along the extending direction of the wiring component 4. Figure 5 Arrow A).

[0038] As explained above, in the vibrating device 1, a double-sided adhesive tape 41 for joining the frame 3 to the external device is disposed on the first surface F1 of the top 12a of the side portion 12. In this embodiment, the side portion 12 is arranged to surround the piezoelectric part 2 from three directions, and the first surface F1 is formed by the top 12a of the side portion 12 and the flange portion 13 provided on the top 12a. Therefore, the frame 3 can be tightly sealed to the external device via the double-sided adhesive tape 41, and the installation state of the vibrating device 1 to the external device can be stabilized.

[0039] Furthermore, in the vibrating device 1, the wiring component 4 is joined to the double-sided tape 41 mounted on the cutout 33 at the position of the first surface F1 via the cutout 33 provided at the top 12a of the side surface 12. On the other hand, it is not joined to the second surface F2, which is one level below the first surface F1. By joining the wiring component 4 to the double-sided tape 41 on the first surface F1, it is possible to prevent the wiring component 4 from shaking around the piezoelectric part 2, thus avoiding any impact on the accuracy of the cavity design. By not joining the wiring component 4 to the second surface F2, even if dimensional errors occur at the cutout, the flatness of the joining component P on the first surface F1 is maintained, thus maintaining the stability of the installation state of the vibrating device 1. Therefore, in the vibrating device 1, the cavity characteristics around the piezoelectric part 2 can be easily ensured, thereby improving the acoustic characteristics.

[0040] In this embodiment, tension is applied to the wiring component 4 between the piezoelectric part 2 and the cutout part 33 along the extending direction of the wiring component 4. Therefore, even when vibration is applied to the frame 3, the generation of collision noise caused by interference between the wiring component 4 and the frame 3 can be suppressed. Thus, the influence of vibration on the characteristics of the cavity can be avoided.

[0041] In this embodiment, the side portion 12 is smoothly continuous with the bottom portion 11, and is inclined outward from the edge relative to the bottom portion 11. Therefore, vibration is effectively transmitted from the bottom portion 11, where the piezoelectric part 2 is disposed, to the side portion 12, and the vibration of the side portion 12 and the vibration of the bottom portion 11 can be fully extracted as output. Thus, the acoustic characteristics are further improved.

[0042] The present invention is not limited to the above embodiments. For example, in the above embodiments, the planar shape of the bottom part 11 of the frame 3 is trapezoidal, but the planar shape of the bottom part 11 is not limited to this, and can also be other shapes such as rectangle, square, circle, ellipse, etc.

[0043] Furthermore, in the above embodiment, the double-sided tape 41 is separated from the second surface F2 at an interval equal to the depth of the cut portion 33, but as... Figure 6 As shown, the double-sided tape 41 can also be bonded to at least a portion of the second side F2. Figure 6 In this example, the double-sided tape 41 flexes towards the cutout 33 on both sides of the wiring component 4, and joins with the second surface F2 near the apex of the flexed portion. With this structure, by joining the wiring component 4 with both the first surface F1 and the second surface F2, it is possible to more reliably prevent the wiring component 4 from wobbling around the piezoelectric part 2.

[0044] When the double-sided tape 41 is bonded to at least a portion of the second surface F2, it is preferable that the bonding area S1 of the wiring component 4 and the double-sided tape 41 is larger than the bonding area S2 of the second surface F2 and the double-sided tape 41. In this case, over-bonding between the second surface F2 and the double-sided tape 41 can be avoided, and the flatness of the double-sided tape 41 on the first surface F1 can be maintained.

Claims

1. A vibrating device, wherein, have: The piezoelectric part includes a piezoelectric element; The frame holds the piezoelectric part; Wiring components, which are electrically connected to the piezoelectric part; and A connecting component that engages the frame with an external device. The frame has a bottom portion on which the piezoelectric part is fixed and a side portion that is erected on the edge of the bottom portion. The side portion has a first surface formed at the top of the side portion and a second surface that descends one level from the first surface through a cutout formed at the top. The joining component extends along the first surface in a manner that it is mounted on the cut-out portion. The wiring component engages with the joining component at the position of the first surface, and passes through the cutout in a state of non-engagement with the second surface.

2. The vibration device according to claim 1, wherein, The engaging component engages with at least a portion of the second surface.

3. The vibration device according to claim 2, wherein, The joint area of ​​the wiring component and the joint component is greater than the joint area of ​​the second surface and the joint component.

4. The vibration device according to any one of claims 1 to 3, wherein, Tension is applied to the wiring component between the piezoelectric portion and the cut portion along the extension direction of the wiring component.

5. The vibration device according to any one of claims 1 to 4, wherein, The side portion is smoothly continuous with the bottom portion and slopes outward relative to the bottom portion in a manner that opens towards the edge portion.

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