阅读说明：本技术 压电器件、振动构造体以及压电传感器 (Piezoelectric device, vibration structure, and piezoelectric sensor ) 是由 远藤润 桥本顺一 富永亨 大寺昭三 于 2019-11-19 设计创作，主要内容包括：压电器件具备：具有第1主面与第2主面并具有压电性的膜片(12)、配置于膜片(12)的第1主面侧的第1基板(10)以及连接膜片(12)与第1基板(10)的第1连接部件(15)。第1连接部件(15)是热固性树脂,第1连接部件(15)的固化温度低于膜片(12)进行热收缩的温度。(A piezoelectric device is provided with: a diaphragm (12) having a 1 st main surface and a 2 nd main surface and having piezoelectricity, a 1 st substrate (10) disposed on the 1 st main surface side of the diaphragm (12), and a 1 st connection member (15) connecting the diaphragm (12) and the 1 st substrate (10). The 1 st connecting member (15) is a thermosetting resin, and the curing temperature of the 1 st connecting member (15) is lower than the temperature at which the film (12) undergoes thermal shrinkage.)

1. A piezoelectric device is characterized by comprising:

a diaphragm having a 1 st main surface and a 2 nd main surface and having piezoelectricity;

a 1 st substrate disposed on the 1 st principal surface side of the diaphragm; and

a 1 st connecting member connecting the diaphragm and the 1 st substrate,

the 1 st connecting member is a thermosetting resin,

the curing temperature of the 1 st connecting part is lower than the temperature at which the membrane is subjected to thermal shrinkage.

2. A piezoelectric device according to claim 1,

the curing temperature is 130 ℃ or lower.

3. A vibration structure characterized in that,

a piezoelectric device according to claim 1 or 2,

the diaphragm is deformed in the plane direction by the application of a voltage,

the 1 st substrate is a frame-shaped member,

the vibration structure further includes:

a vibrating portion having an area smaller than an area of an inner side surrounded by the frame-like member in a plan view, the vibrating portion being connected to the diaphragm and vibrating in the plane direction due to deformation of the diaphragm in the plane direction; and

and a support portion connected to the frame-shaped member and supporting the vibration portion.

4. The vibration structure according to claim 3, wherein the vibration structure further comprises a vibration member,

further comprises a 2 nd connecting member for connecting the vibrating portion and the diaphragm,

the 2 nd connecting member is a thermosetting resin,

the curing temperature of the 2 nd connecting part is lower than the temperature at which the membrane is subjected to thermal shrinkage.

5. The vibration structure according to claim 3, further comprising:

a surface base material disposed between the frame-shaped member and the diaphragm; and

a 2 nd connecting member for connecting the surface base material and the frame-like member,

the 1 st connecting member connects the surface base material and the membrane.

6. The vibration structure according to claim 5, wherein the vibration structure further comprises a vibration member,

the 2 nd connecting member is a thermosetting resin,

the curing temperature of the 2 nd connecting part is higher than that of the 1 st connecting part.

7. The vibration structure according to claim 5 or 6, wherein the vibration structure further comprises a vibration suppressing member,

the frame-like member is formed integrally with the 2 nd connecting member.

8. The vibration structure according to claim 5 or 6, wherein the vibration structure further comprises a vibration suppressing member,

the 2 nd connecting member is formed integrally with the surface base material.

9. The vibration structure according to any one of claims 3 to 8,

the frame-like member, the vibrating portion, and the support portion are formed of the same member.

10. A piezoelectric sensor is characterized by comprising:

a piezoelectric device according to claim 1 or 2,

A 2 nd substrate disposed between the 1 st substrate and the diaphragm, and

a 3 rd connecting part connecting the 1 st substrate and the 2 nd substrate,

the 1 st connecting member connects the diaphragm and the 2 nd substrate.

11. The piezoelectric sensor according to claim 10,

the 3 rd connecting member is a thermosetting resin,

the curing temperature of the 3 rd connecting part is lower than the temperature at which the membrane is subjected to thermal shrinkage.

Technical Field

The invention relates to a piezoelectric device, a vibration structure, and a piezoelectric sensor.

Background

Conventionally, a diaphragm having piezoelectricity is often used by being bonded and fixed to a substrate or the like via an adhesive.

For example, japanese patent application laid-open No. 2017-199858 (patent document 1) discloses a piezoelectric actuator in which a piezoelectric body is bonded to a substrate using a thermosetting resin as an adhesive.

Patent document 1: japanese patent laid-open publication No. 2017-199858

However, since the temperature at which the piezoelectric body of ceramic is bonded is high, when a piezoelectric film or the like made of an organic material is used for the piezoelectric body, the piezoelectric film may be thermally denatured at a temperature higher than that of the ceramic (for example, about 150 degrees).

Disclosure of Invention

Accordingly, an object of the present invention is to provide a piezoelectric device, a vibrating structure, and a piezoelectric sensor that can suppress denaturation due to heat generated when a diaphragm is bonded to a substrate or the like.

The piezoelectric device according to the present invention includes: a diaphragm having a 1 st main surface and a 2 nd main surface and having piezoelectricity; a 1 st substrate disposed on the 1 st main surface side of the diaphragm; and a 1 st connection member connecting the diaphragm and the 1 st substrate. The 1 st connecting member is a thermosetting resin, and the curing temperature of the 1 st connecting member is lower than the temperature at which the film thermally contracts.

The vibration structure according to the present invention includes: the piezoelectric device, the vibrating portion, and the supporting portion according to the present invention are described above. The diaphragm is deformed in a plane direction by application of a voltage, and the 1 st substrate is a frame-shaped member. The vibrating portion has an area smaller than an area of an inner side surrounded by the frame-like member in a plan view, is connected to the diaphragm, and vibrates in the plane direction due to deformation of the diaphragm in the plane direction. The support portion is connected to the frame-shaped member and supports the vibration portion.

The piezoelectric sensor according to the present invention includes: a piezoelectric device according to the present invention, a 2 nd substrate disposed between the 1 st substrate and the diaphragm, and a 3 rd connecting member connecting the 1 st substrate and the 2 nd substrate. The 1 st connecting member connects the diaphragm and the 2 nd substrate.

By forming the piezoelectric device, the vibration structure, and the piezoelectric sensor according to the present invention, the diaphragm and the substrate can be bonded to each other while suppressing thermal deformation of the diaphragm.

Drawings

Fig. 1 (a) is a perspective view of the vibration structure 1, fig. 1 (B) is a sectional view of the vibration structure 1, and fig. 1 (C) is a partially enlarged view of fig. 1 (B).

Fig. 2 is a plan view of the vibration structure 1.

Fig. 3 (a) is a perspective view of the vibration structure 2, fig. 3 (B) is a sectional view of the vibration structure 2, and fig. 3 (C) is a partially enlarged view of fig. 3 (B).

Fig. 4 (a) is a perspective view of the vibration structure 3, fig. 4 (B) is a sectional view of the vibration structure 3, and fig. 4 (C) is a partially enlarged view of fig. 4 (B).

Fig. 5 (a) is a perspective view of the vibration structure 4, fig. 5 (B) is a cross-sectional view of the vibration structure 4, and fig. 5 (C) is a partially enlarged view of fig. 5 (B).

Detailed Description

Fig. 1 (a) is a perspective view of the vibration structure 1 according to embodiment 1 of the present invention, and fig. 1 (B) is a sectional view taken along line a-a of the vibration structure 1 in fig. 1 (a). Fig. 1 (C) is an enlarged view of a connection portion where the piezoelectric diaphragm 12 and the frame member 10 are connected in fig. 1 (B).

The vibration structure 1 includes: the piezoelectric element includes a frame-shaped member 10, a region 11 surrounded by the frame-shaped member 10, a piezoelectric diaphragm 12, a support portion 13, a vibrating portion 14, and a 1 st connecting member 15.

The frame-like member 10 has a rectangular shape in plan view, and the frame-like member 10 has an area 11 surrounded by the frame-like member 10. In the region 11 surrounded by the frame-like member 10, the support portion 13 and the vibrating portion 14 are arranged. The region 11 surrounded by the frame-like member 10 is formed with 21 st openings 11A arranged at both ends in the longitudinal direction of the frame- like member 10 and 2 nd openings 11B arranged at both ends in the short direction by the support portion 13 and the vibrating portion 14. The 1 st opening 11A is rectangular and is long in the short side direction of the frame-like member 10. The 2 nd opening 11B is rectangular and is long in the longitudinal direction of the frame-like member 10.

The vibrating portion 14 is rectangular in plan view and is disposed in the region 11 surrounded by the frame-like member 10. The area of the vibrating portion 14 is smaller than the area of the region 11 surrounded by the frame-like member 10.

The support portion 13 connects the vibration portion 14 and the frame member 10, and the vibration portion 14 is supported by the frame member 10. In this example, the support portion 13 is a rectangle that is long in the short side direction of the frame-shaped member 10, which is a direction orthogonal to the direction in which the piezoelectric diaphragm 12 extends and contracts, and holds the vibrating portion 14 at both ends in the long side direction of the vibrating portion 14.

In this example, the frame-shaped member 10, the vibrating portion 14, and the supporting portion 13 are formed of the same member (for example, acrylic resin, PET, Polycarbonate (PC), glass epoxy, FRP, metal, glass, or the like). In other words, the frame-shaped member 10, the vibrating portion 14, and the supporting portion 13 are formed by punching 1 rectangular plate member along the shapes of the 1 st opening 11A and the 2 nd opening 11B. The frame-shaped member 10, the vibrating portion 14, and the supporting portion 13 may be different members, but they can be easily manufactured by forming them from the same member. Alternatively, since the vibration part 14 is formed of the same member, it is not necessary to use another member (a member having creep deterioration) such as rubber for supporting the vibration part 14, and the vibration part 14 can be stably held for a long period of time. In addition, when these are the same member and are punched out, the natural vibration cycles of the plurality of support portions 13 are completely the same, and therefore, variation in vibration of the vibrating portion 14 when the vibrating portion 14 is vibrated can be reduced. However, in the present invention, these components need not be formed of the same component. For example, when different members are used for the plurality of support portions 13, the operation of the vibration portion 14 can be adjusted. For example, if a material having a high elastic modulus such as rubber is used for the support portion 13, the magnitude of the voltage applied to the piezoelectric diaphragm 12 can be reduced.

The piezoelectric diaphragm 12 is connected to the frame member 10 and the vibrating portion 14. The piezoelectric diaphragm 12 is a diaphragm that deforms in the planar direction when a voltage is applied. The piezoelectric diaphragm 12 is a rectangle that is long along the longitudinal direction of the frame-like member 10 in a plan view. The piezoelectric diaphragm 12 is made of polyvinylidene fluoride (PVDF), for example. In addition, the piezoelectric diaphragm 12 may be formed of a chiral polymer. Examples of the chiral polymer include L-type polylactic acid (PLLA) and D-type polylactic acid (PDLA).

In the case where PVDF is used for the piezoelectric diaphragm 12, since PVDF has water resistance, the same vibration can be performed regardless of the humidity environment in which the electronic device provided with the vibration member in this example is placed.

In addition, when PLLA is used for the piezoelectric diaphragm 12, since PLLA is a material having high permeability, if the electrode attached to PLLA and the vibrating portion 14 are transparent materials, the internal state of the device can be visually recognized, and thus the device can be easily manufactured. PLLA has no pyroelectricity, and therefore can vibrate in the same manner regardless of the temperature environment in which it is placed.

When the piezoelectric diaphragm 12 is formed of PLLA, it is cut as follows: the outer peripheries are made to have piezoelectricity by making an angle of approximately 45 degrees with respect to the extending direction.

The 1 st end in the longitudinal direction of the piezoelectric diaphragm 12 is connected to the 1 st end in the longitudinal direction of the frame-like member 10. The 2 nd end of the piezoelectric diaphragm 12 is connected to the 2 nd end in the longitudinal direction of the vibrating portion 14.

As shown in fig. 1 (B) and 1 (C), the piezoelectric diaphragm 12 is connected to the frame member 10 and the vibrating portion 14 via the 1 st connecting member 15. The frame member 10 is rectangular in shape extending along the short side direction in a plan view. The 1 st connecting member 15 has a certain thickness, and connects the piezoelectric diaphragm 12 and the vibrating portion 14 at a position separated by a certain distance without bringing the piezoelectric diaphragm 12 into contact with the vibrating portion 14. Thus, the electrodes, not shown, provided on both main surfaces of the piezoelectric diaphragm 12 are less likely to contact the vibrating portion 14, and therefore, even if the piezoelectric diaphragm 12 expands and contracts to vibrate the vibrating portion 14, the electrodes can be prevented from being scraped.

The 1 st connecting member 15 is made of a thermosetting resin. The thermosetting resin used for the 1 st connecting member 15 is a thermosetting resin having a curing temperature of 130 degrees or less.

PLLA and PVDF used for the piezoelectric membrane 12 cause a decrease or loss of piezoelectricity and reverse piezoelectricity due to thermal shrinkage and a change in molecular arrangement at a temperature around approximately 150 degrees. Therefore, when the curing temperature of the thermosetting resin used for the 1 st connecting member 15 is 150 degrees or lower, the function of the piezoelectric membrane may be impaired.

For example, when the piezoelectric diaphragm 12 is formed of PVDF, thermal contraction may occur at a temperature of 130 degrees or more, and the contraction of the piezoelectric diaphragm 12 may not be sufficiently transmitted to the frame member 10 and the vibrating portion 14.

That is, the 1 st connecting member 15 is preferably made of a thermosetting resin that is cured at 130 degrees or less.

The curing temperature of the thermosetting resin may be set not to exceed a selected reference temperature based on the curie temperature, the melting point, the thermal shrinkage temperature, the temperature of lowering to a predetermined elastic modulus, and the like, depending on the material and the characteristics of the piezoelectric diaphragm 12 to be used.

In this case, when the curing temperature of the thermosetting resin used for the 1 st connecting member 15 is lower than the predetermined selected reference temperature, the vibration part 14 and the frame member 10 can be bonded to each other while suppressing the deterioration of the characteristics of the piezoelectric diaphragm 12. That is, in this way, the piezoelectric diaphragm 12 can be bonded to the frame-shaped member 10 as the 1 st substrate while suppressing the thermal deformation of the piezoelectric diaphragm 12.

The 1 st link member 15 may be formed of 2 or more different members. In this case, by appropriately selecting the combination of the members in accordance with the stress or the like applied to the 1 st connecting member 15, the vibration of the vibration structure 1 can be stabilized.

The 1 st connecting member 15 may be made of a silicon-based adhesive. In this case, the change in the elastic modulus of the silicon-based adhesive with respect to the temperature change is small as compared with other acrylic-based adhesives and the like, and thus the vibration structure 1 is stable in vibration.

Fig. 2 is a plan view of the vibration structure 1. The piezoelectric diaphragm 12 has planar electrodes formed on both principal surfaces. The planar electrode is connected to a drive circuit not shown. The drive circuit applies a voltage to the planar electrode to expand and contract the piezoelectric diaphragm 12. For example, when the drive circuit applies a negative voltage to the piezoelectric diaphragm 12 to contract the piezoelectric diaphragm 12, the vibrating portion 14 is displaced in the longitudinal direction (rightward direction in the drawing) as shown in fig. 2. The 1 st connecting member 15 is very thin and thus transmits force with little deformation. Therefore, when the piezoelectric diaphragm 12 contracts, the vibrating portion 14 is easily displaced.

When the drive circuit applies a positive voltage to the piezoelectric diaphragm 12, for example, the piezoelectric diaphragm 12 expands. However, even if the piezoelectric diaphragm 12 is extended, the vibrating portion 14 is not easily displaced by only the piezoelectric diaphragm 12 being deflected. Therefore, the drive circuit mainly applies a negative voltage to the piezoelectric diaphragm 12, for example, and causes the piezoelectric diaphragm 12 to expand and contract, thereby vibrating the vibrating portion 14. When the piezoelectric diaphragm 12 is connected in a state in which tension is applied thereto, the supporting portion 13 that is deflected by the initial tension tends to return to its original position when the diaphragm is stretched, and the vibrating portion 14 is displaced. Here, the piezoelectric diaphragm 12 may be configured to expand when a negative charge is applied and contract when a positive charge is applied.

The application of the voltage as described above is repeated. In other words, the drive circuit applies an alternating voltage. The drive waveform may be any waveform such as a rectangular wave, a triangular wave, or a trapezoidal wave. For example, if a sine wave is applied, unnecessary vibration can be reduced, and sound generated by the unnecessary vibration can be reduced.

In the vibration structure 1, the vibrating portion 14 vibrates in the planar direction in the region 11 surrounded by the frame-like member 10 of the frame-like member 10. Therefore, as shown in fig. 1 (B), the thickness of the entire vibration structure 1 is only the sum of the thickness of the piezoelectric diaphragm 12, the thickness of the connecting member 15, and the thickness of the vibrating portion 14, and is very thin. In addition, the piezoelectric diaphragm 22 has elasticity, and thus has shock resistance. In the case where the frame-shaped member 10, the vibrating portion 14, and the supporting portion 13 are each formed of 1 rectangular plate member, there is no need to use another member (a member having creep deterioration) such as rubber for supporting the vibrating portion 14. Therefore, the vibration structure 1 can stably vibrate for a long period of time.

The shape of the vibrating portion 14 is not limited to the shape shown in fig. 2. The frame member 10 does not need to be annular in shape surrounding the entire circumference in plan view, and may have a structure partially opened. The frame member 10 and the vibrating portion 14 do not need to be rectangular in plan view. The frame member 10 and the vibrating portion 14 may have a polygonal shape, a circular shape, an elliptical shape, or the like.

Although the vibration structure 1 has been described above as an example using the piezoelectric diaphragm 12, the structure of the present invention can be used when bonding the piezoelectric diaphragm to the substrate using a thermosetting resin in a piezoelectric device including the piezoelectric diaphragm to the substrate such as the frame-shaped member 10 and the vibrating portion 14.

For example, the piezoelectric diaphragm 12 may be used not only as a vibration structure but also as a piezoelectric sensor.

In this case, the piezoelectric diaphragm 12 is bonded to a substrate or the like using a thermosetting resin, as in the case of the vibration structure 1. In this case, as the thermosetting resin used for the vibration structure 1, a thermosetting resin that cures at 130 degrees or less is preferably used. With this configuration, a sensor that suppresses thermal denaturation of the piezoelectric diaphragm 12 can be provided.

Fig. 3 (a) is a perspective view of the vibration structure 2 according to embodiment 2 of the present invention, and fig. 3 (B) is a cross-sectional view of the vibration structure 2 of fig. 3 (a) taken along line B-B. Fig. 3 (C) is an enlarged view of a connection portion where the piezoelectric diaphragm 22 and the frame member 20 are connected in fig. 3 (B).

The vibration structure 2 includes: the piezoelectric element includes a frame-shaped member 20, a region 21 surrounded by the frame-shaped member 20, a piezoelectric diaphragm 22, a support portion 23, a vibrating portion 24, a 1 st connecting member 25, a 2 nd connecting member 26, and a surface base 27.

The vibration structure 2 is different from the vibration structure 1 in that the front surface base 27 and the 2 nd connecting member 26 are provided. Therefore, the same structure as the vibration structure 1 will not be described below.

The 1 st connecting member 25 is made of a thermosetting resin, and the curing temperature thereof is a temperature lower than the temperature at which the piezoelectric diaphragm 22 is denatured or the melting point by heat generation. For example, in the case where the temperature of thermal-induced denaturation of the piezoelectric diaphragm 22 is 150 degrees, the curing temperature is 130 degrees.

The surface base material 27 is connected to the 1 st connecting member 25 by the piezoelectric diaphragm 22. The front surface base material 27 is connected to the frame member 20 via the 2 nd connecting member 26.

The surface substrate 27 is made of an insulating material such as polyimide, for example. The 2 nd connecting member 26 is formed of a thermosetting resin, like the 1 st connecting member 25. The curing temperature of the thermosetting resin used for the 2 nd connecting member 26 is higher than that of the thermosetting resin used for the 1 st connecting member 25.

When the frame-like member 10 is made of a metal member such as SUS, a curable resin such as a thermosetting resin used for the 1 st connecting member 25 that is cured at a relatively low temperature has a smaller elastic modulus than a thermosetting resin that is cured at a high temperature, and thus the vibrating portion 24 and the adhesive bond may be weakened.

Therefore, the surface base material 27 and the piezoelectric diaphragm 22 are connected by the 1 st connecting member 25 which is cured at a relatively low temperature using the surface base material 27, and the piezoelectric diaphragm 22 and the frame-like member 20 can be connected by bonding the surface base material 27 and the frame-like member 20 by the 2 nd connecting member 26 which is cured at a higher temperature than the 1 st connecting member 25.

In the case where the piezoelectric diaphragm 22 and the frame member 20 are connected via the 2 nd connecting member 26 and the surface base material 27, the elastic modulus of the entire connected portion is higher than that in the case where the connection is performed only by the 1 st connecting member 25, and therefore, the vibration of the piezoelectric diaphragm 22 can be suppressed from being absorbed and relaxed in the connected portion.

In the above configuration, the description has been given of the portion connecting the piezoelectric diaphragm 22 and the frame member 20, but the present invention is not limited to this, and the same configuration may be adopted for the portion connecting the piezoelectric diaphragm 22 and the vibrating portion 24.

That is, the surface base material 27 and the vibrating portion 24 are bonded by thermosetting resin, and the curing temperature thereof is higher than the curing temperature of the thermosetting resin bonding the piezoelectric diaphragm 22 and the surface base material 27.

Similarly to the portion connecting the piezoelectric diaphragm 22 and the frame-like member 20, the curing temperature of the thermosetting resin bonding the surface base material 27 and the vibrating portion 24 is set higher than the curing temperature of the thermosetting resin bonding the piezoelectric diaphragm 22 and the surface base material 27 even in the portion connecting the piezoelectric diaphragm 22 and the vibrating portion 24, whereby the vibrating portion 24, and the frame-like member 20 and the piezoelectric diaphragm 22 can be more reliably connected.

The surface base material 27 is made of an insulating material. When the surface base material 27 is made of an insulating base material, if an electrode is formed on the piezoelectric diaphragm 22, the electrode on the piezoelectric diaphragm 22 and the vibrating portion 24 do not come into direct contact with each other with expansion and contraction of the piezoelectric diaphragm 22 due to the presence of the surface base material 27. In other words, even in the case where the vibrating portion 24 is formed of metal, it is possible to suppress the vibrating portion 24 from being short-circuited with the electrode on the piezoelectric diaphragm 22.

In addition, as in the case of the structure of the vibration structure 1, in a piezoelectric device including a piezoelectric diaphragm and a substrate such as the frame-shaped member 20 and the vibration part 24, the structure of the present invention can be used when the piezoelectric diaphragm and the substrate are bonded to each other using a thermosetting resin.

When the structure of the vibration structure 2 is used in a piezoelectric sensor, for example, the vibration structure can be bonded to a substrate without impairing the characteristics of a piezoelectric diaphragm.

That is, the piezoelectric device is provided with a piezoelectric film, an insulating surface base material, and a metal substrate, wherein the piezoelectric film and the surface base material are bonded with a thermosetting resin, the surface base material and the substrate are bonded with a thermosetting resin, and the curing temperature of the thermosetting resin bonding the piezoelectric film and the surface base material is lower than the curing temperature of the thermosetting resin bonding the surface base material and the substrate.

In this configuration, the piezoelectric diaphragm can be reliably bonded to the metal substrate. The substrate is not limited to metal, and may be made of resin or the like.

Fig. 4 (a) is a perspective view of the vibration structure 3 according to embodiment 3 of the present invention, and fig. 4 (B) is a cross-sectional view of the vibration structure 3 of fig. 4 (a) taken along the line C-C. Fig. 4 (C) is an enlarged view of a connecting portion between the piezoelectric diaphragm 32 and the frame member 30 in fig. 4 (B).

As shown in fig. 4 (a), the vibration structure 3 includes: the piezoelectric element includes a frame-shaped member 30, a region 31 surrounded by the frame-shaped member 30, a piezoelectric diaphragm 32, a support portion 33, a vibrating portion 34, a 1 st connecting member 35, a 2 nd connecting member 36, and a surface base 37.

Since the vibration structure 3 is different from the vibration structure 2 in that the 2 nd connecting member 36 is integrally formed with the frame member 30, the same structure is omitted in the vibration structure 3 and the vibration structure 2.

Fig. 4 (B) is a cross-sectional view of the vibration structure 3 in fig. 4 (a), and is an enlarged view of a connection portion where the piezoelectric diaphragm 32 and the frame member 30 are connected.

As shown in fig. 4 (B), the 2 nd connecting member 36 is formed integrally with the frame member 30. In this case, the frame-like member 30 and the 2 nd connecting member 36 are formed of, for example, a thermosetting resin, and are bonded to the surface base material 37.

The curing temperature of the thermosetting resin used for the frame-like member 30 and the 2 nd connecting member 36 is higher than that of the thermosetting resin used for the 1 st connecting member 35.

With this configuration, the frame-like member 30 and the 2 nd connecting member 36 can be reliably bonded to the surface base material 37, and the surface base material 37 can be reliably bonded to the piezoelectric diaphragm 32.

Further, since the frame-shaped member 30 is formed integrally with the 2 nd connecting member 36, the number of components of the entire structure is reduced, and the manufacturing process can be simplified and the cost can be reduced.

Fig. 4 (B) shows a connecting portion between the piezoelectric diaphragm 32 and the frame-shaped member, but the present invention is not limited to this, and the vibrating portion 34 and the 1 st connecting member 45 connecting the vibrating portion 34 and the surface base material 37 are integrally formed in the same manner as the connecting portion between the piezoelectric diaphragm 32 and the vibrating portion 34.

In this case, the vibrating portion 34 is preferably formed integrally with the frame-like member 30 and made of the same thermosetting resin.

With this configuration, in the vibration structure 3, the occurrence of peeling or misalignment at the connecting portion where the frame-like member 30 and the vibrating portion 34 are connected to the piezoelectric diaphragm 32 can be further suppressed.

In addition, the number of components can be further reduced, and further reduction in manufacturing processes and cost can be achieved.

Fig. 5 (a) is a perspective view of the vibration structure 4 according to embodiment 4 of the present invention, and fig. 5 (B) is a D-D sectional view of the vibration structure 4 of fig. 5 (a). Fig. 5 (C) is an enlarged view of a connection portion where the piezoelectric diaphragm 42 and the frame member 40 are connected in fig. 5 (B).

As shown in fig. 5 (a), the vibration structure 4 includes: the piezoelectric element includes a frame-shaped member 40, a region 41 surrounded by the frame-shaped member 40, a piezoelectric diaphragm 42, a support portion 43, a vibration portion 44, a 1 st connection member 45, a 2 nd connection member 46, and a surface base 47.

Since the vibration structure 4 is different from the vibration structure 2 in that the 2 nd connecting member 46 and the surface base material 47 are integrally formed, the same structure is omitted in the vibration structure 4 and the vibration structure 2.

Fig. 5 (B) is a cross-sectional view of the vibration structure 4 in fig. 5 (a), and is an enlarged view of a connection portion where the piezoelectric diaphragm 42 and the frame member 40 are connected.

As shown in fig. 5 (B), the 2 nd connecting member 46 is formed integrally with the surface base material 47.

In this case, the surface base 47 and the 2 nd connecting member 46 are made of, for example, a thermosetting resin, and bonded to the frame member 40.

The curing temperature of the thermosetting resin used for the surface base material 47 and the 2 nd connecting member 46 is higher than that of the thermosetting resin used for the 1 st connecting member 45.

With this configuration, the surface base material 47 and the 2 nd connecting member 46 can be reliably bonded to the frame member 40, and the surface base material 47 and the 2 nd connecting member 46 can be reliably bonded to the piezoelectric diaphragm 42.

Further, the occurrence of peeling and misalignment at the connection portion where the surface base material 47 and the 2 nd connection member 46 are connected can be suppressed.

Further, since the surface base material 47 is formed integrally with the 2 nd connecting member 46, the number of components of the entire structure is reduced, and the manufacturing process can be simplified and the cost can be reduced.

In fig. 5 (B), a connection portion between the piezoelectric diaphragm 42 and the frame-shaped member is shown, but the present invention is not limited to this, and the surface base material 47 and the 1 st connection member 45 connecting the vibration portion 44 and the surface base material 47 may be integrally formed in the same manner as the connection portion between the piezoelectric diaphragm 42 and the vibration portion 44.

With this configuration, in the vibration structure 4, the occurrence of peeling or misalignment at the connection portion where the surface base material 47 and the piezoelectric diaphragm 32 are connected can be further suppressed.

In addition, the number of components can be further reduced, and further reduction in manufacturing processes and cost can be achieved.

The features of embodiments 1 to 4 of the present invention described above can be combined with each other without departing from the spirit of the present invention.

The above embodiments disclosed herein are illustrative in all respects and not restrictive. The technical scope of the present invention is defined by the claims, and includes all modifications equivalent in meaning and within the scope to the description of the claims.

Description of reference numerals

1 … vibration structure; 10 … frame-like member; 11 … area surrounded by frame-like member; 12 … piezoelectric diaphragm; 13 … a support portion; 14 … a vibrating part; 15 … part 1; 26 … part 2; 27 … surface substrate.