JP2001053573A - Piezoelectric component and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize airtightness of a high level by including a piezoelectric substrate, at least one front electrode and at least one rear electrode, including a first cavity layer and a first sealing layer in a first sealing structure body and including a second cavity layer and a second sealing layer in a second shielding structure body. SOLUTION: A front electrode 12 includes a front reed electrode 14, which is continued to the electrode 12 and whose end part is led out to the side end edge of a piezoelectric substrate 11. A rear electrode 13 includes a rear reed electrode 15, which is continued to the electrode 13 and whose end part is led out to the side end edge of the substrate 11. A first sealing structure body 2 is adhered to the front surface of the substrate 11 to form a first cavity 6 for vibration around the electrode 12 and to seal the cavity 6. A second sealing structure body 3 is adhered to the rear surface of the substrate 11 to form a second cavity 7 for vibration around the electrode 13 and to seal the cavity 7. The structure 3 includes a second cavity layer 31 and a second sealing layer 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a filter, for example,
The present invention relates to a piezoelectric component used as a resonator or an oscillator and a method for manufacturing the same.

[0002]

2. Description of the Related Art In a piezoelectric component of this kind, a closed vibration space must be formed around a front electrode and a back electrode. The airtightness of the vibration space, and its internal volume,
It directly affects the characteristics of piezoelectric components. Therefore, in the formation of the vibration space, to form a vibration space having a high degree of air tightness, to form a vibration space supported by a sealing structure that does not cause a failure in air tightness, and to a certain space volume It is extremely important to form a vibrating space. Further, the fact that no residue due to the manufacturing process remains in the vibration space is also an important point for preventing the occurrence of characteristic defects.

[0003] Known documents that disclose techniques for forming a vibration space include, for example, JP-A-64-41309 and JP-A-5-167381. JP 6
In Japanese Patent Application Laid-Open No. 4-41309, after a resist resin is applied to a vibrating portion of a piezoelectric element, an opening communicating with a partial edge of the resist resin is secured on the surface of the piezoelectric element, and a cover resin (cavity) is formed. Layer). Next, after drying the resin for the cover, the resist resin is dissolved with an organic solvent or the like,
The resin is discharged to the outside through the opening of the cover resin, and the cavity after the resist resin is removed is cleaned by means of ultrasonic cleaning or the like. Thereafter, the closed vibration space is formed by sealing the opening.

In Japanese Patent Application Laid-Open No. Hei 5-167381, after a resist resin is applied to a vibrating portion of a piezoelectric element, a resin layer (cavity layer) having an opening smaller than the plane area of the resist resin layer is formed on the resist resin. To form Next, after drying the resin layer (hollow layer), the resist resin is dissolved,
Discharge to the outside through the opening of the cover resin. Then, the sealed vibration space is formed by sealing the opening with the sealing layer. The sealing layer includes a first sealing layer and a second sealing layer. The first encapsulation layer has a recess surrounding the cavity area and is laminated on the cavity layer. A second encapsulation layer is laminated over the first encapsulation layer;
The concave portion of the first sealing layer and the opening connected to the cavity are sealed.

[0005] However, it is difficult to satisfy the above-mentioned conditions required for the vibration space by the above-mentioned known techniques. For example, in JP-A-64-41309,
Since the opening for removing and cleaning the resist resin is located at the edge of the cavity layer, the residue of the resist resin is easily generated in the cavity. In addition, since the thickness of the peripheral portion of the opening in the hollow layer becomes extremely thin, cracks and the like may occur in this portion, and airtightness may be impaired.

In Japanese Patent Application Laid-Open No. Hei 5-167381, when a position shift occurs between an opening portion connected to a hollow portion and a hollow region and a concave portion of the first sealing layer, airtightness tends to be broken. Become.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a piezoelectric component having a highly airtight vibration space and a method for manufacturing the same.

It is another object of the present invention to provide a piezoelectric component having a vibration space in which airtightness is unlikely to break down, and a method of manufacturing the same.

Still another object of the present invention is to provide a piezoelectric component having a vibration space having a certain space volume and a method for manufacturing the same.

Still another object of the present invention is to provide a piezoelectric component having a structure in which a residue due to a manufacturing process hardly remains in a vibration space, and a method of manufacturing the same.

[0011]

In order to solve the above-mentioned problems, the present invention discloses two types of piezoelectric components.

<Piezoelectric Component According to First Aspect> A piezoelectric component according to a first aspect includes a piezoelectric element, a first sealing structure,
A second sealing structure.

[0014] The piezoelectric element includes a piezoelectric substrate, at least one front electrode, and at least one back electrode. The front electrode is provided on a front surface of the piezoelectric substrate, and the back electrode is provided on a back surface of the piezoelectric substrate and faces the front electrode.

[0014] The first sealing structure includes a first cavity layer and a first sealing layer. The first cavity layer has a first cavity which is adjacent to the surface of the piezoelectric substrate on one surface and penetrates around the vibrating portion including the front electrode with the same width in the layer thickness direction. One surface of the first sealing layer is adjacent to the other surface of the first cavity layer, and seals the first cavity.

[0015] The second sealing structure includes a second cavity layer and a second sealing layer. The second cavity layer has one surface adjacent to the back surface of the piezoelectric substrate, and forms a second cavity penetrating around the vibrating portion including the back electrode with the same width in the layer thickness direction. One surface of the second sealing layer is adjacent to the other surface of the second cavity layer, and seals the second cavity.

As described above, in the piezoelectric component according to the present invention, the front electrode is provided on the surface of the piezoelectric substrate.
The back electrode is provided on a back surface of the piezoelectric substrate and faces the front electrode. The front electrode and the back electrode constitute a vibrating part. Therefore, piezoelectric vibration characteristics by the front and back electrodes can be obtained.

The first cavity layer forming the first sealing structure forms a first cavity around the vibrating portion including the front electrode. The first sealing layer constituting the first sealing structure has a first sealing layer.
And sealing the first cavity. The second cavity layer forming the second sealing structure forms a second cavity around the vibrating portion including the back electrode. The second sealing layer constituting the second sealing structure is provided on the second cavity layer and seals the second cavity. Therefore, the piezoelectric vibration is performed in the first cavity and the second cavity sealed by the first sealing structure and the second sealing structure.

Since the first cavity penetrates the same width in the thickness direction of the first cavity layer, it is possible to completely remove the resist resin usually used for forming the first cavity. For this reason, it is possible to avoid poor characteristics due to residues of the resist resin.

A first sealing layer is deposited on one surface of the first cavity layer and seals the first cavity. Such a first sealing layer may be provided in a plane with respect to one surface of the first cavity layer, and thus the position of the first sealing layer with respect to the first cavity layer, which has been conventionally required. No alignment is required. Therefore, there is no possibility that the airtightness is broken due to the displacement.

Further, the first sealing layer may be provided in a plane with respect to one surface of the first hollow layer, so that a vibration space having a high degree of airtightness can be formed. In addition, a sufficient overlapping area is ensured by the planar arrangement of the first sealing layer with respect to the first cavity layer, so that a vibration space in which airtightness does not easily break down can be obtained.

Further, the inner volume of the first cavity (vibration space) is set to a constant space volume determined by its plane area and the thickness of the first cavity layer. For this reason, certain characteristics can be secured.

It is clear that the second sealing structure can also obtain the above-described effects with respect to the first sealing structure.

The method for manufacturing a piezoelectric component according to the first aspect described above includes a step of forming the first sealing structure and the second sealing structure.

The step of forming the first sealing structure includes:
A first resist resin is applied to the front surface and the back surface of a piezoelectric substrate having a large number of sets of electrodes each consisting of a front electrode and a back electrode opposed to each other so as to individually cover the front electrodes. I do. Then, a first resin layer for a first cavity layer is formed on the surface of the piezoelectric substrate around the first resist resin. Next, a step of removing the first resist resin to form a hole for each of the front electrodes, and then forming the first sealing layer on the first resin layer is included.

The step of forming the second sealing structure includes:
A second resist resin is applied to the back surface of the piezoelectric substrate so as to individually cover each of the back electrodes. Then, a second resin layer for a second cavity layer is formed on the back surface of the piezoelectric substrate around the second resist resin.
Next, a step of removing the second resist resin to form a second hole for each of the back electrodes, and thereafter forming a second sealing layer on the second resin layer. Including.

According to this step, little residue from the manufacturing process remains in the vibration space. Further, it is possible to manufacture a piezoelectric component having a high degree of airtightness, hardly causing breakdown in airtightness, and having a vibration space having a certain space volume.

<Piezoelectric Component According to Second Aspect> A piezoelectric component according to a second aspect includes a piezoelectric element, a first sealing structure,
It includes a second sealing structure and a third sealing structure. The piezoelectric element, a piezoelectric substrate, at least one front electrode,
At least one back electrode.

The front electrode is provided on a surface of the piezoelectric substrate. The back electrode is provided on a back surface of the piezoelectric substrate and faces the front electrode. The front electrode and the back electrode constitute a vibrating part.

[0029] The first sealing structure includes a first cavity layer and a first sealing layer. The first cavity layer includes two first divided layers that are spaced apart. One surface of the first division layer is adjacent to the surface of the piezoelectric substrate, and forms a first cavity at the interval around a vibrating portion including the front electrode. One surface of the first sealing layer is the first sealing layer.
Adjacent to the other surface of the divided layer.

[0030] The second sealing structure includes a second cavity layer and a second sealing layer. The second cavity layer includes two second division layers that are spaced apart. The second division layer has one surface adjacent to the back surface of the piezoelectric substrate,
Around the vibrating portion including the back electrode,
To form a cavity. One surface of the second sealing layer is adjacent to the other surface of the second division layer.

The third sealing structure includes the piezoelectric element,
Attached to both sides of the assembly including the first sealing structure and the second sealing structure, sealing the first cavity and the second cavity at the two sides.

In the piezoelectric component according to the second aspect, the front electrode is provided on a surface of the piezoelectric substrate. The back electrode is provided on a back surface of the piezoelectric substrate and faces the front electrode. Therefore, piezoelectric vibration characteristics by the front and back electrodes can be obtained.

The first cavity layer constituting the first sealing structure forms a first cavity around the front electrode. A first encapsulation layer is deposited over the first cavity layer. The second cavity layer forming the second sealing structure forms a second cavity around the vibrating portion including the back electrode. The second sealing layer is a second sealing layer.
Is adhered on the cavity layer. The third sealing structure is
A first cavity and a second cavity are attached to both sides of the assembly including the piezoelectric element, the first sealing structure and the second sealing structure.
Is sealed on both sides. Therefore, the piezoelectric element performs piezoelectric vibration in the first cavity and the second cavity sealed by the first sealing structure, the second sealing structure, and the third sealing structure. become.

The first cavity layer forming the first sealing structure includes two first divided layers spaced from each other, and the first divided layer adheres to the surface of the piezoelectric substrate. In addition, since the first cavity is formed around the front electrode by the distance, a resist resin generally used for forming the first cavity is unnecessary. For this reason, it is possible to avoid poor characteristics due to residues of the resist resin.

The first sealing layer constituting the first sealing structure is attached to the two first divided layers. Such a first sealing layer may be formed in a plane with respect to one surface of the first divided layer, and thus the position of the first sealing layer with respect to the first cavity layer, which has been conventionally required. No alignment is required. Therefore, there is no possibility that the airtightness is broken due to the displacement.

In addition, the first sealing layer may be formed in a plane with respect to one surface of the two divided layers constituting the first cavity layer, so that a highly airtight vibration space is formed. it can. In addition, since a sufficient lamination area is ensured by the planar arrangement of the first sealing layer with respect to the two divided layers constituting the first cavity layer, a vibration space in which the hermeticity does not easily break down can be obtained.

Further, the internal volume of the first cavity (vibration space) is set to a constant space volume determined by the plane area of the gap generated between the first divided layers and the layer thickness of the divided layers.
For this reason, certain characteristics can be secured.

[0038] The second cavity layer constituting the second sealing structure includes two second divided layers spaced from each other, and the second divided layer adheres to the surface of the piezoelectric substrate. In addition, since the second cavity is formed around the vibrating portion including the back electrode by the distance, a resist resin generally used for forming the second cavity is unnecessary. For this reason, it is possible to avoid poor characteristics due to residues of the resist resin.

The second sealing layer constituting the second sealing structure is attached on the two second division layers. Such a second sealing layer may be formed in a plane with respect to one surface of the second divided layer, and thus, the position of the second sealing layer with respect to the second cavity layer, which has been conventionally required. No alignment is required.
Therefore, there is no possibility that the airtightness is broken due to the displacement.

Moreover, the second sealing layer may be formed in a plane with respect to one surface of the second divided layer constituting the second cavity layer, so that a vibration space having a high degree of airtightness can be formed. Can be formed. In addition, since a sufficient lamination area is secured by planar lamination of the second sealing layer with respect to the second division layer forming the second cavity layer, a vibration space that does not easily break in airtightness is provided. can get.

Further, the internal volume of the second cavity (vibration space) is set to a constant space volume determined by the plane area of the space generated between the second divided layers and the layer thickness of the divided layers.
For this reason, certain characteristics can be secured.

The first sealing structure formed by the first sealing structure
And the second cavity formed by the second sealing structure is sealed by the third sealing structure. Since the third sealing structure is attached to both sides of the assembly including the piezoelectric element, the first sealing structure, and the second sealing structure, sufficient Since a sufficient bonding or bonding area can be ensured, a vibration space in which airtightness is unlikely to be broken can be obtained. Further, since the third sealing structure is attached to both side surfaces, the inner capacities of the first cavity and the second cavity do not fluctuate. The inner volumes of the first cavity and the second cavity are set to a constant spatial volume determined by the plane area of the space generated between the divided layers and the layer thickness of the divided layers. For this reason, certain characteristics can be secured.

The method for manufacturing a piezoelectric component according to the second aspect is as follows.
Forming a first sealing structure and the second sealing structure. The step of forming the first sealing structure includes:
On the front surface and the back surface of the piezoelectric substrate provided with a large number of sets of electrodes each consisting of a front electrode and a back electrode opposed to each other, a first resist resin is strip-shaped so as to cover a plurality of the front electrodes in common. Apply to. Thereafter, a first resin layer for a first cavity layer is formed on the surface of the piezoelectric substrate around the first resist resin, and then the first resist resin is removed, A hole including a plurality of the front electrodes is formed, and then the first sealing layer is formed on the first resin layer.

The step of forming the second sealing structure includes:
A second resist resin is applied to the back surface of the piezoelectric substrate in a strip shape so as to cover a plurality of the back electrodes in common. Thereafter, a second resin layer for a second cavity layer is formed on the back surface of the piezoelectric substrate around the second resist resin, and then the second resist resin is removed. Forming a second hole including a plurality of back electrodes;
A second sealing layer is formed on the above resin layer.

According to this step, little residue from the manufacturing process remains in the first and second cavities (vibration spaces). Further, it is possible to manufacture a piezoelectric component having a high degree of airtightness, hardly causing breakdown in airtightness, and having a vibration space having a certain space volume.

The present invention further discloses a specific application example to a piezoelectric component used as, for example, a filter, a resonator or an oscillator. Other objects, configurations and advantages of the present invention will be described in more detail with reference to the accompanying drawings. The accompanying drawings are merely illustrative.

[0047]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS <Piezoelectric Component According to First Aspect> FIG. 1 is an exploded perspective view of a piezoelectric component according to a first aspect, and FIG. 2 is a perspective view showing an assembled state of the piezoelectric component shown in FIG. FIG. 3 is a sectional view taken along line 3-3 in FIG. The illustrated embodiment shows an example of a piezoelectric component suitable for use as a resonator or an oscillator. The illustrated piezoelectric component is a piezoelectric element 1
And a first sealing structure 2 and a second sealing structure 3.

The piezoelectric element 1 comprises a piezoelectric substrate 11 and a front electrode 1
2 and a back electrode 13. The front electrode 12 has a front lead electrode 14 and is provided on the surface of the piezoelectric substrate 11. The front lead electrode 14 is electrically connected to the front electrode 12, and the end is led out to the side edge of the piezoelectric substrate 11. The back electrode 13 is a piezoelectric substrate 1
1 and is opposed to the front electrode 12. Front electrode 1
2 and the back electrode 13 constitute a vibrating part.

The back lead electrode 15 is electrically connected to the back electrode 13, and its end is led out to the side edge of the piezoelectric substrate 11. As a constituent material of the piezoelectric substrate 11, a conventionally well-known material can be used. Front electrode 12, back electrode 13, front lead electrode 14
The back lead electrode 15 can be formed by applying a thin film technique such as sputtering or a thick film technique.

In the embodiment, the front electrode 12 includes the front lead electrode 14. The front lead electrode 14 is electrically connected to the front electrode 12, and the end is led out to the side edge of the piezoelectric substrate 11. The back electrode 13 includes a back lead electrode 15 and the back lead electrode 15.
Are conducted to the back electrode 13, and the end is led out to the side edge of the piezoelectric substrate 11.

The first sealing structure 2 is attached to the surface of the piezoelectric substrate 11, forms a first cavity 6 for vibration around the front electrode 12, and seals the first cavity 6. I do.

The first sealing structure 2 includes a first hollow layer 21
And a first sealing layer 22. The first hollow layer 21
The first cavity 6 is formed around the front electrode 12 by being attached to the surface of the piezoelectric substrate 11. The first cavity layer 21 has a first hole at the center, and the first hole constitutes the first cavity 6. The first sealing layer 22 has a sheet shape, is attached on one surface of the first cavity layer 21, and seals the first cavity 6.

The thickness of the first hollow layer 21 is, for example, 10
It is selected in the range of μm to 80 μm. The thickness of the first sealing layer 22 is set, for example, in a range of 3 μm to 50 μm.

The second sealing structure 3 is attached to the back surface of the piezoelectric substrate 11, forms a second cavity 7 around the back electrode 13 for vibration, and seals the second cavity 7. I do.
The second sealing structure 3 includes a second cavity layer 31 and a second sealing layer 32. The second hollow layer 31 is formed on the piezoelectric substrate 11.
To form a second cavity 7 around the back electrode 13. The second cavity layer 31 has a second hole in the center, and the second hole constitutes the second cavity 7. The second sealing layer 32 is provided on the second cavity layer 31 and seals the second cavity 7.

The thickness of the second cavity layer 31 is, for example, 10
It is selected in the range of μm to 80 μm. The thickness of the second sealing layer 32 is set, for example, in the range of 3 μm to 50 μm.

The first hollow layer 21, the first sealing layer 22, the second hollow layer 31, and the second sealing layer 32 can be formed by applying a synthetic resin by screen printing, for example.

As described above, in the piezoelectric component according to the first embodiment, the front electrode 12 is provided on the surface of the piezoelectric substrate 11. The back electrode 13 is provided on the back surface of the piezoelectric substrate 11 and faces the front electrode 12. Front electrode 12 and back electrode 13
Constitutes a vibrating section. Therefore, the front electrode 12 and the back electrode 1
The piezoelectric vibration characteristics according to No. 3 are obtained.

The first cavity layer 21 forming the first sealing structure 2 forms the first cavity 6 around the vibrating portion including the front electrode 12. The first sealing layer 22 constituting the first sealing structure 2 is provided on the first cavity layer 21 and seals the first cavity 6. The second forming the second sealing structure 3
The cavity layer 31 forms the second cavity 7 around the vibrating portion including the back electrode 13. The second sealing layer 32 constituting the second sealing structure 3 is provided on the second cavity layer 31 and seals the second cavity 7. Therefore, the first sealing structure 2
In addition, the piezoelectric vibration is performed in the first cavity 6 and the second cavity 7 sealed by the second sealing structure 3.

The first cavity layer 21 constituting the first sealing structure 2 has a first hole which penetrates the same width in the layer thickness direction and has a first hole around the front electrode 12. A first cavity 6 is formed by a hole. Since the first holes forming the first cavity 6 penetrate through the first cavity layer 21 with the same width in the thickness direction of the first cavity layer 21, the resist resin usually used for forming the first cavity 6 is completely filled. Can be removed. For this reason,
It is possible to avoid poor characteristics due to residues of the resist resin.

In the embodiment, the first sealing layer 22 has a sheet shape and is attached on one surface of the first cavity layer 21 to seal the first cavity 6. Such a first sealing layer 22 may be attached to one surface of the first cavity layer 21 in a planar manner.
It is not necessary to align the first sealing layer 22 with the first sealing layer 22. Therefore, there is no possibility that the airtightness is broken due to the displacement.

Further, the first sealing layer 22 may be stuck on one surface of the first cavity layer 21 in a plane, so that a vibration space having a high degree of airtightness can be formed. Further, since the first sealing layer 22 is attached to the first cavity layer 21 in a planar manner, a sufficient attaching area is ensured, so that a vibration space in which the hermeticity does not easily break down can be obtained.

The first sealing layer 22 can also be formed by means such as screen printing. Also in this case, the first
The sealing layer 22 may be formed in a plane with respect to one surface of the first cavity layer 21, so that the alignment of the first sealing layer 22 with respect to the first cavity layer 21 which has been conventionally required is performed. Becomes unnecessary. Therefore, there is no possibility that the airtightness is broken due to the displacement.

The thickness of the first and second cavity layers 21 and 31 is selected in the range of 10 μm to 80 μm,
When the layer thickness of the sealing layers 22 and 32 is set in the range of 3 μm to 50 μm, a particularly high airtightness maintaining function can be obtained.

Further, the internal volume of the first cavity 6 is a constant space defined by the plane area of the first hole provided in the first cavity layer 21 and the layer thickness of the first cavity layer 21. Set to volume. For this reason, certain characteristics can be secured.

Although the description is omitted, it is clear that the above-described effects of the first sealing structure 2 can be obtained in the second sealing structure 3 as well.

The embodiment further includes a top plate 23, a base substrate 4, and two connection electrodes 51 and 52. Top plate 23
Is bonded onto the first sealing layer 22 with an adhesive. The top plate 23 can be made of a ceramic sheet or an aramid sheet.

The base substrate 4 includes an insulating substrate 40, a first terminal electrode 41, and a second terminal electrode 42. In the embodiment, the third terminal electrode 43 is also illustrated. The base substrate 4 includes the piezoelectric element 1 and the first
An assembly constituted by the sealing structure 2 and the second sealing structure 3 is supported. Thereby, the reinforcing effect by the base substrate 4 is obtained, and a piezoelectric component having high mechanical strength is obtained.

The first terminal electrode 41 is composed of the base substrate 4, the second sealing layer 32, the second cavity layer 31, the piezoelectric substrate 1, the first
In the assembly composed of the hollow layer 21 and the first sealing layer 22, the front lead electrode 14 is formed on the side end surface from which the lead electrode 14 is led out, and is formed on a side end surface different from the side end surface.

The first terminal electrode 42 includes the base substrate 4, the second sealing layer 32, the second cavity layer 31, the piezoelectric substrate 1,
In the assembly composed of the hollow layer 21 and the first sealing layer 22, the rear lead electrode 15 is formed on the lead-out side end face, and further formed on a side end face different from this side end face. The base 40 constituting the base substrate 4 can be made of ceramic.

The first terminal electrode 41 and the second terminal electrode 4
2, a part drawn to a side end face different from the side end face from which the front lead electrode 14 and the lead electrode 15 are led out,
It is used for external solder connection when mounted on a circuit board or the like. Therefore, it is desirable to have characteristics excellent in solderability. Specifically, the lowermost layer in contact with the insulating substrate 40 is a silver layer formed by baking, and a nickel plating layer is provided thereon to serve as a solder erosion prevention layer for the silver layer. A composite plating film structure in which a plating layer is provided to improve solderability can be given.

In the embodiment, the first terminal electrodes 41 to the third
Are formed in a band shape around the assembly at a distance from each other. The first terminal electrode 41 is disposed so that its edge is along the side edge of the piezoelectric substrate 11, and the second terminal electrode 42 has its side edge that is different from the first terminal electrode 41. On the opposite side, it is arranged along the side edge of the piezoelectric substrate 11.

The connection electrodes 51 and 52 are attached to the side surface of the assembly, and the end of the first terminal electrode 41 is connected to the front lead electrode 14.
, And the end of the second terminal electrode 42 is connected to the end of the back lead electrode 15. In the case of the embodiment, the connection electrodes 51 and 52 are attached to opposing side surfaces of the assembly and the base substrate 4. The connection electrodes 51 and 52 are, for example,
A thin film can be formed by employing a thin film forming process such as sputtering or vapor deposition. Connection electrode 51,
52 may be a part of the terminal electrodes 41 and 42,
It may be different from the terminal electrodes 41 and 42.

According to the above-described structure, it is apparent that a through conductor penetrating the piezoelectric substrate 11 in the front and back directions and a land (conductor pattern) for connecting the through conductor are not required, and therefore, the size is reduced. A piezoelectric component suitable for the above can be obtained.

Moreover, by providing the connection electrodes 51 and 52 at positions different from the external soldering regions of the first terminal electrode 41 and the second terminal electrode 42, the connection electrodes 51 and 52 are provided.
52 can be placed outside the influence of the solder attached to the external connection terminal electrodes 41 to 42, and the reliability can be improved.
In the case of the illustrated embodiment, of the four side surfaces of the insulating substrate 40,
The connection electrodes 51 and 52 are attached to other side surfaces that are different from the side surfaces on which the first terminal electrode 41 and the second terminal electrode 42 appear by approximately 90 degrees, so that the first terminal electrode 41 and the second When the second terminal electrode 42 is soldered on the circuit board,
The solder does not flow around the connection electrodes 51 and 52.

Further, since the connection electrodes 51 and 52 can be kept out of the influence of the solder attached to the external connection terminal electrodes, the connection electrodes 51 and 52 are formed by the first and second terminal electrodes 41 and 42. It can be made of a conductive material different from the above, for example, a thin film or the like. First and second terminal electrodes 4
Each of the reference numerals 1 and 42 can have a multi-layered plating film structure in consideration of the adhesion to the base substrate 4 and the soldering characteristics. Therefore, a piezoelectric component having excellent solderability can be obtained.

Further, in the embodiment, the front lead electrode 14 and the back lead electrode 15 have end electrodes 16 and 17 at the ends led out to the side edges of the piezoelectric substrate 11, and the film thickness is different from that of other parts It is thicker than. According to such a structure, the front lead electrode 14 and the rear lead electrode 15 and the connection electrodes 51, 5
2 can be increased, and the reliability of the electrical connection and the mechanical connection can be improved.

The thickness including the front lead electrode 14 and the end electrode 16, and the thickness including the back lead electrode 15 and the end electrode 17 are 0.5 μm when viewed from the end face appearing outside.
It is preferable to select the range of m to 20 μm. With such a thickness, disconnection failure due to thermal shock or the like can be reliably avoided.

The piezoelectric substrate 11, the base substrate 4, and the top plate 23
Is set so that the difference between the thermal expansion coefficients is within ± 5 ppm. Specifically, the thermal expansion coefficient of the piezoelectric substrate 11 is α
1, the coefficient of thermal expansion of the base substrate 4 is α2,
Assuming that the thermal expansion coefficient of No. 3 is α3, it is to satisfy −5 ppm ≦ α1−α2 ≦ 5 ppm−5 ppm ≦ α2-α3 ≦ 5 ppm−5 ppm ≦ α1-α3 ≦ 5 ppm. When the difference between the coefficients of thermal expansion satisfies such a condition, it is possible to suppress the deviation of the characteristics caused by the thermal stress to a minimum value. In such a combination, the base substrate 4 is made of ceramic, the piezoelectric substrate 11 is made of piezoelectric ceramic,
The top plate 23 is made of ceramic or aramid fiber. Another combination is that the base substrate 4 and the top plate 23 are made of a ceramic material having the same composition as the piezoelectric substrate 11.

FIG. 4 is an exploded perspective view showing another embodiment of the piezoelectric component according to the present invention, FIG. 5 is a perspective view of the piezoelectric component shown in FIG. 4 in an assembled state, and FIG. 6 is a line 6-6 in FIG. FIG. In the figures, the same components as those shown in FIGS. 1 to 3 are denoted by the same reference numerals. The illustrated embodiment shows an example of a piezoelectric component suitable for use as a filter or the like.

The piezoelectric element 1 comprises a piezoelectric substrate 11 and a front electrode 1
2 and a back electrode 13. The front electrode 12 and the back electrode 13 have an electrode structure suitable for use as a filter or the like. In the embodiment, two front electrodes 12 are provided.

FIG. 7 is a plan view of the piezoelectric element 1, and FIG. 8 is a bottom view of the piezoelectric element 1 shown in FIG. As shown, each of the front electrodes 12, 12 has two divided electrodes 121,
122. Of the two divided electrodes 121 and 122,
The split electrodes 122 are connected to each other between the front electrodes 12-12. In the embodiment, the divided electrodes 1 of the front electrodes 12 and 12 are used.
The reference numerals 22 and 122 are connected to each other via a capacitor electrode 123 in the middle.

In the two front electrodes 12, 12, two divided electrodes 1 included in the front electrode 12 on the left side (in the figure)
Of the electrodes 21 and 122, the split electrode 121 that is not connected between the front electrodes 12-12 has the first front lead electrode 141. The end of the first front lead electrode 141 is led out to the side edge of the piezoelectric substrate 11. In the embodiment, it is led to the left corner (in FIG. 7).

The right front electrode 12 has two divided electrodes 12
Of the electrodes 1 and 122, the split electrode 121 that is not connected between the front electrodes 12 and 12 has the second front lead electrode 142. The end of the second front lead electrode 142 is led out to the side edge of the piezoelectric substrate 11. Each end of the first front lead conductor 141 and the second front lead conductor 142 is led out to the opposite side edges of the piezoelectric substrate 11. In the embodiment, it is led to the right corner (in FIG. 7).

The back electrode 13 is provided on the back surface of the piezoelectric substrate 11 and faces the front electrodes 12 and 12. In the case of the embodiment, the back electrode 13 also overlaps with the capacitor electrode 123 on the front side, and also functions as a capacitor electrode.

The back electrode 13 has a back lead electrode 15. The back lead electrode 15 is electrically connected to the back electrode 13, and an end is led out to a side edge of the piezoelectric substrate 11. In the case of the embodiment, the back lead electrode 15 is guided to a substantially intermediate portion between both side edges of the piezoelectric substrate 11.

The description will be continued with reference to FIGS. 4 to 6 again. The first sealing structure 2 is attached to the surface of the piezoelectric substrate 11,
First cavity 6 for vibration around front electrodes 12, 12
1 and 62 are formed, and the first cavities 61 and 62 are sealed. The first hollow layer 21 constituting the first sealing structure 2 has two first holes in portions corresponding to the front electrodes 12, 12, and the first holes are the first holes. One cavity 61, 62 is formed. The first sealing layer 22 has a sheet shape and is attached on one surface of the first cavity layer 21 to seal the first cavities 61 and 62.

The second cavity layer 31 forming the second sealing structure 3 has two second holes in a portion corresponding to the vibrating portion of the back electrode 13. The holes form the second cavities 71 and 72. The second sealing layer 32 has a sheet shape and is attached on one surface of the second cavity layer 31 to seal the second cavities 71 and 72.

As described above, the first cavity layer 21 forming the first sealing structure 2 forms the first cavities 61 and 62 around the front electrodes 12 and 12. The first sealing layer 22 constituting the first sealing structure 2 includes a first hollow layer 21.
And seals the first cavities 61 and 62. Second
Is formed around the back electrode 13 facing the front electrode 12, the second cavity 71,
72 is formed. The second sealing layer 32 constituting the second sealing structure 3 is provided on the second cavity layer 31 and seals the second cavities 71 and 72. Therefore, piezoelectric vibration is performed in the first cavities 61 and 62 and the second cavities 71 and 72 sealed by the first sealing structure 2 and the second sealing structure 3.

The first cavity layer 21 constituting the first sealing structure 2 has a first hole that penetrates the same width in the layer thickness direction and has a first hole around the front electrode 12. First cavities 61 and 62 are formed by the holes. Since the two first holes forming the first cavities 61 and 62 penetrate with the same width in the thickness direction of the first cavity layer 21, it is usual to form the first cavities 61 and 62. The resist resin used can be completely removed. For this reason, it is possible to avoid poor characteristics due to residues of the resist resin.

The first sealing layer 22 has a sheet shape,
Adhered on one side of the first cavity layer 21 and sealing the two first cavities 61,62. Such a first sealing layer 22
May be attached to one surface of the first cavity layer 21 in a planar manner, so that the alignment of the first sealing layer 22 with respect to the first cavity layer 21 which is conventionally required is unnecessary. Therefore, there is no possibility that the airtightness is broken due to the displacement.

Moreover, the first sealing layer 22 may be stuck to one surface of the first cavity layer 21 in a plane, so that a highly airtight vibration space can be formed. Further, since the first sealing layer 22 is attached to the first cavity layer 21 in a planar manner, a sufficient attaching area is ensured, so that a vibration space in which the hermeticity does not easily break down can be obtained.

Further, the first cavities 61 and 62 (vibration space)
Is set to a constant space volume determined by the plane area of the first hole provided in the first cavity layer 21 and the layer thickness of the first cavity layer 21. For this reason, certain characteristics can be secured.

Although the description is omitted, it is clear that the second sealing structure 3 can also obtain the above-described effects with respect to the first sealing structure 2.

The first terminal electrode 41 and the second terminal electrode 42 provided on the base substrate 4 are arranged on opposite sides of the insulating substrate 40, and the respective ends are connected to the front lead electrode 1.
41, 142 are led out to the side edges facing the led-out side edges. The first terminal electrode 41 and the second terminal electrode 42 are cut off on the surface side on which the assembly including the piezoelectric element 1, the first sealing structure 2, and the second sealing structure 3 is mounted. .

The third terminal electrode 43 is formed on the insulating substrate 40, and the end is led out to a side edge facing the side edge from which the back lead electrode 15 is led out. In the embodiment, a cross-shaped pattern is formed on one surface of the insulating substrate 40 on which the assembly is mounted, and both ends thereof are led out to both side ends of the insulating substrate 40.

Of the connection electrodes 51 to 54, the connection electrode 51
Is attached to the side surface of the assembly and the base substrate 4, and connects the end of the first terminal electrode 41 to the end of the first front lead electrode 141. The connection electrode 52 is attached to the side surface of the assembly and the base substrate 4, and connects the end of the second terminal electrode 42 to the end of the second front lead electrode 142. The connection electrodes 53 and 54 conduct both ends of the third terminal electrode 43 to both ends of the back lead electrode 15.

It is apparent that the piezoelectric components shown in FIGS. 4 to 6 also do not require a through conductor penetrating the piezoelectric substrate 11 in the front-to-back direction and a land (conductor pattern) for connecting the through conductor. Yes, and therefore, a piezoelectric component suitable for miniaturization can be obtained.

Moreover, by providing the connection electrodes 51 to 54 at positions different from the external soldering regions of the first terminal electrode 41 to the third terminal electrode 43, the connection electrodes 51 to 54 are provided.
4 can be placed outside the influence of the solder attached to the external connection terminal electrodes 41 to 43, and the reliability can be improved. In the case of the illustrated embodiment, of the four side surfaces of the insulating substrate 40, the connection electrodes 51 to 54 are different from the side surfaces on which the surfaces of the first terminal electrode 41 to the third terminal electrode 43 appear by approximately 90 degrees. Since the first terminal electrode 41 to the third terminal electrode 43 are soldered on the circuit board because they are attached to the side surfaces, the solder does not flow around the connection electrodes 51 and 52.

Further, since the connection electrodes 51 to 54 can be kept out of the influence of the solder attached to the external connection terminal electrodes, the connection electrodes 51 to 54 are formed by the first terminal electrodes 41 to the third terminal electrodes. It can be formed of a conductive material different from the electrode 43, for example, a thin film or the like. First terminal electrodes 41 to 41
The third terminal electrode 43 can have a multi-layered plating film structure in consideration of the adhesion to the base substrate 4 and the soldering characteristics, and therefore, a piezoelectric component having excellent solderability can be obtained.

<Embodiment of Second Embodiment> FIG. 9 is an exploded perspective view of the piezoelectric component according to the second embodiment, FIG. 10 is a perspective view of the piezoelectric component shown in FIG. 9 in an assembled state, and FIG. Of 1
FIG. 12 is a sectional plane view taken along line 1-11. In the figure, FIG.
8, the same reference numerals are given to the same components. The piezoelectric component according to the second aspect includes a piezoelectric element 1, a first sealing structure 2, a second sealing structure 3, and third sealing structures 24 and 25.

The piezoelectric element 1 includes a piezoelectric substrate 11 and a front electrode 1.
2 and a back electrode 13. The front electrode 12 is provided on the surface of the piezoelectric substrate 11. The back electrode 13 is provided on the back surface of the piezoelectric substrate 11 and faces the front electrode 12.

The first sealing structure 2 includes a first hollow layer 21
And a first sealing layer 22. The first hollow layer 21
First divided layers 211 and 21 arranged at an interval d1
2 inclusive. The first divided layers 211 and 212 are
Around the vibrating part including the front electrode 12 attached to the surface of
First cavities 6 are formed with a distance d1. The first sealing layer 22 is in a sheet shape, straddles the first division layers 211 and 212 constituting the first cavity layer 21, and is attached thereon.

The second sealing structure 3 includes a second cavity layer 31.
And a second sealing layer 32. The second cavity layer 31
Second divided layers 311, 31 arranged at an interval d2
2 inclusive. The second divided layers 311 and 312 correspond to the piezoelectric substrate 1.
A second cavity 7 with a distance d2 is formed around the vibrating portion including the back electrode 13 and attached to the back surface of the first cavity 7. The second sealing layer 32 straddles and is attached to the second divided layers 311, 312 constituting the second cavity layer 31.

The third sealing structures 24 and 25 are attached to both sides of the assembly including the piezoelectric element 1, the first sealing structure 2 and the second sealing structure 3, Cavity 6 and and second
Is sealed on both sides.

In the piezoelectric component according to the second aspect, the front electrode 12 is provided on the surface of the piezoelectric substrate 11. Back electrode 1
3 is provided on the back surface of the piezoelectric substrate 11 and faces the front electrode 12. The front electrode 12 and the back electrode 13 constitute a vibrating part. Therefore, the piezoelectric vibration characteristics by the front electrode 12 and the back electrode 13 can be obtained.

The first cavity layer 21 forming the first sealing structure 2 forms the first cavity 6 around the front electrode 12. The first sealing layer 22 is attached on the first cavity layer 21. The second cavity layer 31 forming the second sealing structure 3 forms the second cavity 7 around the front electrode 12. The second sealing layer 32 is attached on the second cavity layer 31. Third sealing structures 24 and 25 are attached to both sides of the assembly including the piezoelectric element 1, the first sealing structure 2 and the second sealing structure 3, and the first cavity 6 and And the second
Is sealed on both sides. Therefore, the piezoelectric element 1 has the first cavity 6 and the second cavity sealed by the first sealing structure 2, the second sealing structure 3, and the third sealing structures 24 and 25. 7, the piezoelectric vibration is performed.

The first cavity layer 21 forming the first sealing structure 2 is formed of the first divided layer 2 arranged at a distance d1.
11, 212, and the first divided layers 211, 212 include:
Attached to the surface of the piezoelectric substrate 11, around the front electrode 12,
Since the first cavities 6 are formed at the interval d1, it is possible to omit a resist resin that is generally used for forming the first cavities 6. For this reason, it is possible to avoid poor characteristics due to residues of the resist resin.

When a resist resin is used to form the first cavity 6, the resist resin can be completely removed from between the first divided layers 211 and 212.
For this reason, it is possible to avoid poor characteristics due to residues of the resist resin.

The first sealing layer 22 forming the first sealing structure 2 is formed of the first divided layer 2 forming the first hollow layer 21.
11 and 212, and are attached on it. Such a first sealing layer 22 includes first divided layers 211, 2
Since it is only necessary to stick it on one side of 12 in a plane,
The positioning of the first sealing layer 22 with respect to the first cavity layer 21, which is conventionally essential, is not required. Therefore, there is no possibility that the airtightness is broken due to the displacement.

In addition, the first sealing layer 22 may be attached to one surface of the first divided layers 211 and 212 constituting the first cavity layer 21 in a planar manner, so that high airtightness is achieved. Can be formed. Also, the first cavity layer 2
1 for the two divided layers 211 and 212 constituting
A sufficient bonding area is secured by planarly bonding the sealing layer 22 to a vibration space in which airtightness is unlikely to be broken.

The first sealing layer 22 can be formed by means such as screen printing. Also in this case, the first
The sealing layer 22 may be formed in a plane with respect to one surface of the first cavity layer 21, so that the alignment of the first sealing layer 22 with respect to the first cavity layer 21 which has been conventionally required is performed. Becomes unnecessary. Therefore, there is no possibility that the airtightness is broken due to the displacement.

Further, the internal volume of the first cavity 6 (vibration space) is a constant area determined by the plane area of the interval d1 generated between the divided layers 211 and 212 and the layer thickness of the first divided layers 211 and 212. Set to the space volume. For this reason, certain characteristics can be secured.

In the second sealing structure 3, the same function and effect as described in the first sealing structure 2 can be obtained.

The first cavity 6 formed by the first sealing structure 2 and the second cavity 7 formed by the second sealing structure 3 are connected to the third sealing structures 24 and 25. Sealed. Since the third sealing structures 24, 25 are attached to both sides of the assembly including the piezoelectric element 1, the first sealing structure 2, and the second sealing structure 3, sufficient adhesion or Affixing area can be secured. Therefore, a vibration space in which the hermeticity hardly breaks down can be obtained. Also, the third sealing structure 2
4 and 25 are attached to both side surfaces, so that the inner volumes of the first cavity 6 and the second cavity 7 do not fluctuate. The internal volumes of the first cavity 6 and the second cavity 7 are the same as those of the first division layer (2
11-212) and the plane areas of the distances d1 and d2 generated between the second divided layers (311-312) and the divided layers (21
1, 212) and (311, 312) are set to a constant space volume determined by the layer thickness. For this reason, certain characteristics can be secured.

Next, a method for manufacturing a piezoelectric component according to the present invention will be described.

<Method of Manufacturing Piezoelectric Component According to First Aspect>
12 to 30 show a manufacturing process of the piezoelectric component according to the first embodiment. First, as shown in FIG. 12, a large number of front electrodes 12 are formed on a large wafer-like piezoelectric substrate 11 in a predetermined pattern. The front electrode 12 can be formed by a high-precision pattern forming technique using photolithography, or can also be formed by screen printing or the like. The front electrode 12 is formed as a pattern having the front lead electrode 14.

Next, as shown in FIG. 13, an end electrode 16 made of the same electrode material as the front electrode 12 is laminated on the end of the front lead electrode 14.

A similar process is performed on the back surface of the piezoelectric substrate 11. 14 and 15 show the wafer-shaped piezoelectric substrate 11 thus obtained. The front electrode 12 and the front lead electrode 14 are formed on the surface of the piezoelectric substrate 11, and the back electrode 1 is formed on the back surface.
3 and the back lead electrode 15 are formed.

Next, as shown in FIGS. 16 and 17, resist resins 60 and 70 that cover the front electrode 12 and the back electrode 13 in a range larger than the outer diameter are applied and dried. As the resist resins 60 and 70, those which can be easily dissolved and removed with water, an alkali or an organic solvent are used.

Next, as shown in FIGS. 18 and 19, a resist resin 60
The resins 21 and 31 are applied so as to fill the area without 70, dried, and fixed. The resins 21 and 31 constitute the first and second hollow layers 21 and 31 (see FIGS. 1 to 3).

Next, as shown in FIGS. 20 and 21, the resist resins 60 and 70 are removed. Resist resin 60, 70
Can be easily dissolved and removed with water, an alkali or an organic solvent as described above. Resist resin 60, 70
Are removed, spaces 6 and 7 serving as the first cavity and the second cavity are generated. The first hole constituting the first cavity 6 and the second hole constituting the second cavity 7 have the same width in the thickness direction of the first cavity layer 21 and the second cavity layer 31. Since it penetrates, the resist resins 60 and 70 are
The first cavity layer 21 and the second cavity layer 31 can be discharged in the plane direction and completely removed. For this reason, it is possible to avoid poor characteristics due to residues of the resist resins 60 and 70.

Next, as shown in FIGS. 22 and 23, a first sealing layer 22 and a second sealing layer 32 are laminated. As the laminating means, means such as sheet pasting or screen printing can be used. Thereby, an assembly including the wafer-shaped piezoelectric substrate 11, the first sealing layer 22, and the second sealing layer 32 is obtained. In this case, the first and second sealing layers 2
The first and second hollow layers 21 and 31 may be formed in a plane with respect to one surface of the first and second hollow layers 21 and 31. In addition, the positioning of the second sealing layers 22 and 32 becomes unnecessary. Therefore, there is no possibility that the airtightness is broken due to the displacement.

Further, the first and second sealing layers 22 and 32
With respect to one surface of the first and second cavity layers 21 and 31,
Since the vibration space may be formed in a plane, a vibration space having high airtightness can be formed. Also, the first and second hollow layers 21,
The planar lamination of the first and second sealing layers 22 and 32 with respect to 31 secures a sufficient lamination area, so that a vibration space in which airtightness does not easily break down can be obtained.

Further, the inner volumes of the first and second cavities 6 and 7 are the same as the first and second cavities 21 and 31 provided in the first and second cavity layers 21 and 31, respectively.
Area of the first and second holes, and the first and second hollow layers 2
It is set to a constant space volume determined by the layer thicknesses 1 and 31. For this reason, certain characteristics can be secured.

Next, as shown in FIGS. 24 and 25, the base substrate 4 is bonded to the second sealing layer 32, and the top plate 23 is bonded to the first sealing layer 22. Base substrate 4 and top plate 23
In bonding, the adhesive force of the second sealing layer 32 and the first sealing layer 22 is used, or the second sealing layer 3
The adhesive force of the adhesive layer applied to the surfaces of the second and first sealing layers 22 can be used.

The base substrate 4 is manufactured in a step different from the step of manufacturing an assembly including the piezoelectric element 1, the first sealing structure 2, and the second sealing structure 3. This base substrate 4 preferably has a first terminal electrode 41,
The second terminal electrode 42 and the third terminal electrode 43 are formed in a belt shape. Between the adjacent piezoelectric elements, the first terminal electrode 41 and the second terminal electrode 42 are formed integrally.
Next, as shown in FIG. 26, the base substrate 4, the wafer-shaped piezoelectric substrate 11, the first cavity layer 21, the first sealing layer 22, the second cavity layer 31, the second sealing layer 32, and The assembly including the top plate 23 is connected to the X1-X1 line, the X2-X2 line and the (Y1-Y
(Line 1) to (Y3-Y3 line). As the cutting means, a dicing saw can be used. Through this cutting step, a single piezoelectric component is obtained as shown in FIG.

Next, the first terminal electrode 4 is provided on the side of the assembly.
First, a second terminal electrode 42, a third terminal electrode 43, and connection electrodes 51 and 52 are formed. As a result, the end of the first terminal electrode 41 is conducted to the end of the front lead electrode 14,
The end of the second terminal electrode 42 is conducted to the end of the back lead electrode 15 (see FIGS. 1 to 3). First terminal electrodes 41 to 41
The third terminal electrode 43 and the connection electrodes 51 and 52 can be formed by forming a thin film by a thin film forming means such as sputtering and then plating.

FIG. 29 shows another efficient cutting method. In the case of FIG. 29, the base substrate 4 and the wafer-like piezoelectric substrate 1
26, when cutting the assembly including the first hollow layer 21, the first sealing layer 22, the second hollow layer 31, the second sealing layer 32, and the top plate 23, in FIG. Y1 line, Y2-Y
2 lines, Y3-Y3 lines,. . . To obtain a strip-shaped assembly in which a plurality of sets of electrodes including a front electrode and a back electrode are arranged in a line.

Next, as shown in FIG. 30, a first terminal electrode 41, a second terminal electrode 42, and a third terminal electrode 43 are formed on the side surfaces of the strip-shaped assembly. Thereafter, X in FIG.
Cut the strip assembly along the line 1-X1, X2-X2. Then, as shown in FIG. 28, connection electrodes 51 and 52 are formed on the cut surface. As a result, the end of the first terminal electrode 41 is conducted to the end of the front lead electrode 14,
The end of the terminal electrode 42 is electrically connected to the end of the back lead electrode 15 (see FIGS. 1 to 3). According to the manufacturing method shown in FIGS. 29 and 30, the first terminal electrode 41 to the third terminal electrode 43 can be simultaneously formed on a plurality of piezoelectric elements included in the strip-shaped assembly. The efficiency of the terminal electrode forming step is improved.

Although not shown, the piezoelectric components shown in FIGS. 4 to 6 can be manufactured by the same steps. Of course, FIG.
When manufacturing the piezoelectric component of FIG. 6, the pattern of the front and back electrodes, the number of connection electrodes, the pattern of the terminal electrodes, and the like must be changed.

<Method of Manufacturing Piezoelectric Component According to Second Aspect>
FIGS. 31 to 48 show a manufacturing process of the piezoelectric component according to the second embodiment. Also in the method for manufacturing a piezoelectric component according to the second aspect, the manufacturing steps illustrated in FIGS. 12 to 15 are adopted, and the front electrode 12 and the back electrode 1 are placed on the wafer-shaped piezoelectric substrate 11.
3. A front lead electrode 14, a back lead electrode 15, and end electrodes 16 and 17 are formed. After the electrode formation process is completed,
The first sealing structure forming step, the second sealing structure forming step, and the third sealing structure forming step are performed.

In the first sealing structure forming step, FIG.
As shown at 32, a first resist resin 60 having a width d1 is applied to the surface of the wafer-shaped piezoelectric substrate 11 in a band shape so as to cover a plurality of the front electrodes 12 in common.

Also in the step of forming the second sealing structure, the second resist resin 70 is formed in a band shape with a width d2 on the back surface of the piezoelectric substrate 11 so as to cover a plurality of the back electrodes 13 in common. Apply.

Next, as shown in FIGS. 33 and 34, the surface of the piezoelectric substrate 11 around the first resist resin 60 is
The first resin layer 210 is formed. In addition, a second resin layer 310 is formed on the back surface of the piezoelectric substrate 11 around the second resist resin 70.

Next, as shown in FIGS. 35 and 36, on the surface side of the piezoelectric substrate 11, the first resist resin 60 is removed, and the first hole 6 including a plurality of front electrodes 12 is formed. Form. The second resist resin 70 is also removed on the back surface side of the piezoelectric substrate 11 to form a second hole 7 including a plurality of back electrodes 13. As described above, the resist resins 60 and 70 can be easily dissolved and removed with water, an alkali or an organic solvent. After the resist resins 60 and 70 are removed, first and second holes 6 and 7 serving as a first cavity and a second cavity are formed. Resist resin 60, 7
0 can be completely removed by discharging in three directions of the front surface, the back surface, and the side surface. Therefore, the resist resin 60,
It is possible to avoid characteristic failure due to the residue of No. 70.

Next, as shown in FIGS. 37 and 38, the first resin layer 2 is formed as a continuation step of the first sealing structure forming step.
The first sealing layer 22 is formed on the first resin layer 10, and the second sealing layer 32 is formed on the second resin layer 310 as a continuation step of the second sealing structure forming step. The first sealing layer 22
It has a sheet shape, is straddled over the first divided layers 211 and 212 constituting the first hollow layer 21, and is attached thereon. As described above, the first sealing layer 22 may be stuck on one surface of the first divided layers 211 and 212 in a planar manner. The positioning of the sealing layer 22 becomes unnecessary. Therefore, there is no possibility that the airtightness is broken due to the displacement. The same applies to the second sealing layer 32.

In addition, since the first sealing layer 22 has only to be planarly attached to one surface of the first divided layers 211 and 212 constituting the first cavity layer 21, a high degree of airtightness is obtained. Can be formed. Also, the first cavity layer 2
1 for the first divided layers 211 and 212 constituting
A sufficient bonding area is secured by planarly bonding the sealing layer 22 to a vibration space in which airtightness is unlikely to be broken. A similar operation and effect is obtained by the second sealing layer 3
2 can also be obtained.

Further, the internal volume of the first cavity 6 is a constant space determined by the plane area of the interval d1 generated between the first divided layers 211 and 212 and the layer thickness of the first divided layers 211 and 212. Set to volume. For this reason, certain characteristics can be secured. The same applies to the internal volume of the second cavity 7.

As described above, the first and second sealing layers 22 and 32 can also be formed by means such as screen printing. Also in this case, the first and second sealing layers 2
The first and second cavity layers 21 and 31 may be formed in a plane with respect to one surface of the first and second cavity layers 21 and 31. And the second sealing layer 3 with respect to the second cavity layer 31
The alignment of 2 is unnecessary. Therefore, there is no possibility that the airtightness is broken due to the displacement.

Next, as shown in FIGS. 39 and 40, the base substrate 4 is bonded to the second sealing layer 32, and the top plate 23 is bonded to the first sealing layer 22. Base substrate 4 and top plate 23
In bonding, the adhesive force of the second sealing layer 32 and the first sealing layer 22 is used, or the second sealing layer 3
The adhesive force of the adhesive layer applied to the surfaces of the second and first sealing layers 22 can be used.

The base substrate 4 is manufactured in a step different from the step of manufacturing an assembly including the piezoelectric element 1, the first sealing structure 2, and the second sealing structure 3. This base substrate 4 preferably has a first terminal electrode 41,
The second terminal electrode 42 and the third terminal electrode 43 are formed in a belt shape. Between the adjacent piezoelectric elements, the first terminal electrode 41 and the second terminal electrode 42 are formed integrally.

Next, as shown in FIGS. 41 and 42, the base substrate 4, the wafer-shaped piezoelectric substrate 11, the first cavity layer 21, the first sealing layer 22, the second cavity layer 31, and the second Sealing layer 32
The assembly including the top plate 23 and the X1-X1 line, X2-X
Cut along line 2 and lines (Y1-Y1) to (Y3-Y3). As the cutting means, a dicing saw can be used. Through this cutting step, FIG.
As shown in (1), a single piezoelectric component (unfinished) is obtained.

Next, as shown in FIG. 44, third sealing layers 24 and 25 are formed. In this step, third sealing layers 24 and 25 are attached to both side surfaces of the assembly. The first cavity 6 formed by the first sealing structure 2 and the second cavity 7 formed by the second sealing structure 3
Is sealed by the sealing structures 24 and 25. Since the third sealing layers 24 and 25 are attached to both sides of the assembly including the piezoelectric element 1, the first sealing structure 2 and the second sealing structure 3, sufficient bonding or bonding is performed. The mounting area can be secured.
Therefore, a vibration space in which the hermeticity hardly breaks down can be obtained. In addition, since the third sealing layers 24 and 25 are attached to both side surfaces, the inner volumes of the first cavity 6 and the second cavity 7 do not fluctuate. The inner volumes of the first cavity 6 and the second cavity 7 are divided layers (211-212) and (311-31).
2) The plane area of the gap generated between them and the divided layer (211
212) and (311, 312) are set to a constant space volume determined by the layer thickness. For this reason, certain characteristics can be secured.

Next, as shown in FIG. 45, a first terminal electrode 41, a second terminal electrode 42, a third terminal electrode 43, and connection electrodes 51 and 52 are formed on the side surface of the assembly.
As a result, the end of the first terminal electrode 41 is conducted to the end of the front lead electrode 14, and the end of the second terminal electrode 42 is conducted to the end of the back lead electrode 15. First to third terminal electrodes 41 to 43, and connection electrodes 51 and 52
Can be formed by forming a thin film by a thin film forming means such as sputtering and then plating.

FIG. 46 shows another efficient cutting method. In the case of FIG. 46, the base substrate 4 and the wafer-like piezoelectric substrate 1
41, when cutting the assembly including the first cavity layer 21, the first sealing layer 22, the second cavity layer 31, the second sealing layer 32 and the top plate 23, in FIG. Y1 line, Y2-Y
2 lines, Y3-Y3 lines,. . . To obtain a strip-shaped assembly in which a plurality of sets of electrodes including a front electrode and a back electrode are arranged in a line.

Next, as shown in FIG. 47, third sealing layers 24 and 25 are formed on the side surfaces of the strip-shaped assembly. next,
As shown in FIG. 48, the first terminal electrode 41, the second terminal electrode 42, and the third terminal electrode 4
Form 3 Thereafter, the strip assembly is cut along the lines X1-X1 and X2-X2 in FIG. And FIG.
As shown in (1), connection electrodes 51 and 52 are formed on the cut surface. As a result, the end of the first terminal electrode 41 is conducted to the end of the front lead electrode 14, and the end of the second terminal electrode 42 is conducted to the end of the back lead electrode 15. Figures 46 to 4
According to the manufacturing method shown in FIG. 8, the first terminal electrode 41 to the third terminal electrode 43 can be simultaneously formed on the plurality of piezoelectric elements included in the strip-shaped assembly. The efficiency of the process is improved.

Although not shown, the filter piezoelectric components shown in FIGS. 4 to 6 and having the second aspect can be manufactured by the same process.

[0148]

As described above, according to the present invention, the following effects can be obtained. (A) It is possible to provide a piezoelectric component having a highly airtight vibration space and a method of manufacturing the same. (B) It is possible to provide a piezoelectric component having a vibration space in which airtightness is unlikely to break down, and a method for manufacturing the same. (C) It is possible to provide a piezoelectric component having a vibration space having a certain space volume and a method for manufacturing the same. (D) It is possible to provide a piezoelectric component having a structure in which a residue due to a manufacturing process hardly remains in a vibration space, and a method for manufacturing the same.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a piezoelectric component according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a piezoelectric component according to the present invention.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is an exploded perspective view showing another embodiment of the piezoelectric component according to the present invention.

5 is a perspective view of the piezoelectric component shown in FIG. 4 in an assembled state.

FIG. 6 is a sectional view taken along line 6-6 in FIG. 5;

FIG. 7 is a plan view of a piezoelectric element included in the piezoelectric component shown in FIGS.

FIG. 8 is a bottom view of a piezoelectric element included in the piezoelectric component shown in FIGS.

FIG. 9 is an exploded perspective view of a piezoelectric component according to a second embodiment of the present invention.

10 is a perspective view of the piezoelectric component shown in FIG. 9 in an assembled state.

FIG. 11 is a sectional view taken along line 11-11 of FIG. 10;

FIG. 12 is a perspective view illustrating a manufacturing process of the piezoelectric component according to the first embodiment.

FIG. 13 is a perspective view showing a manufacturing step after the step shown in FIG. 12;

FIG. 14 is a perspective view showing a manufacturing step after the step shown in FIG. 13;

FIG. 15 is an enlarged cross-sectional view showing the step shown in FIG. 14;

FIG. 16 is a perspective view showing a manufacturing process after the process shown in FIGS. 14 and 15;

FIG. 17 is an enlarged cross-sectional view showing the step shown in FIG. 16;

FIG. 18 is a perspective view showing a manufacturing step after the step shown in FIGS.

FIG. 19 is an enlarged cross-sectional view showing the step shown in FIG. 18;

FIG. 20 is a perspective view showing a manufacturing process after the process shown in FIGS. 18 and 19;

FIG. 21 is an enlarged cross-sectional view showing a step shown in FIG. 20;

FIG. 22 is a perspective view showing a manufacturing step after the step shown in FIGS.

FIG. 23 is an enlarged cross-sectional view showing the step shown in FIG. 22;

FIG. 24 is a perspective view showing a manufacturing process after the process shown in FIGS. 22 and 23.

FIG. 25 is an enlarged cross-sectional view showing a step shown in FIG. 24;

FIG. 26 is a perspective view showing a manufacturing step after the step shown in FIGS. 24 and 25.

FIG. 27 is a perspective view of a piezoelectric component (unfinished) obtained by the cutting step shown in FIG. 26;

FIG. 28 is a perspective view of a piezoelectric component (completed) obtained by applying electrodes to the piezoelectric component (unfinished) shown in FIG. 27;

FIG. 29 is a perspective view showing another cutting method.

30 is a perspective view showing a manufacturing process after the process shown in FIG. 29.

FIG. 31 is a perspective view illustrating a manufacturing process of the piezoelectric component according to the second embodiment.

FIG. 32 is an enlarged cross-sectional view showing the step shown in FIG. 31;

FIG. 33 is a perspective view showing a manufacturing step after the step shown in FIGS. 31 and 32;

FIG. 34 is an enlarged cross-sectional view showing a step shown in FIG. 33;

FIG. 35 is a perspective view showing a manufacturing step after the step shown in FIGS. 33 and 34;

FIG. 36 is an enlarged cross-sectional view showing the step shown in FIG. 35;

FIG. 37 is a perspective view showing a manufacturing step after the step shown in FIGS. 35 and 36.

38 is an enlarged cross-sectional view showing a step shown in FIG. 37;

FIG. 39 is a perspective view showing a manufacturing step after the step shown in FIGS. 37 and 38.

40 is an enlarged cross-sectional view showing the step shown in FIG. 39;

FIG. 41 is a perspective view showing a manufacturing step after the step shown in FIGS. 39 and 40.

FIG. 42 is an enlarged cross-sectional view showing a step shown in FIG. 41;

43 is a perspective view of a piezoelectric component (unfinished) obtained through the steps shown in FIGS. 41 and 42. FIG.

FIG. 44 is a perspective view of a piezoelectric component (unfinished) obtained by attaching a third sealing layer to the piezoelectric component (unfinished) shown in FIG. 43.

FIG. 45 is a perspective view of a piezoelectric component (completed) obtained by applying electrodes to the piezoelectric component (unfinished) shown in FIG. 44;

FIG. 46 is a perspective view showing another cutting method.

FIG. 47 is a perspective view showing a manufacturing step after the step shown in FIG. 46.

FIG. 48 is a perspective view showing a manufacturing step after the step shown in FIG. 47.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric element 2 1st sealing structure 3 2nd sealing structure 6, 61, 62 1st cavity 7, 71, 72 2nd cavity

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Souichi Kiriyama 1-1-13 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation (72) Inventor Seiichi Tajima 1-13-1 Nihonbashi, Chuo-ku, Tokyo Within TDK Corporation (72) Inventor Ikuo Kato 1-13-1 Nihombashi, Chuo-ku, Tokyo F-term within TDK Corporation (reference) MM14

Claims (22)

[Claims] 1. A piezoelectric element, a first sealing structure, and a second sealing structure.
Wherein the piezoelectric element includes a piezoelectric substrate, at least one front electrode, and at least one back electrode, and the front electrode is a piezoelectric substrate of the piezoelectric substrate. The back electrode is provided on the front surface, the back electrode is provided on the back surface of the piezoelectric substrate, and is opposed to the front electrode. The first sealing structure includes a first cavity layer, A first cavity layer, one surface of which is adjacent to the surface of the piezoelectric substrate and penetrates around the vibrating portion including the front electrode with the same width in the layer thickness direction. The first sealing layer has one surface adjacent to the other surface of the first cavity layer and seals the first cavity, and the second sealing structure Includes a second cavity layer and a second encapsulation layer, wherein the second cavity layer has one surface adjacent to the back surface of the piezoelectric substrate, A second cavity penetrating the same width in the layer thickness direction around the vibrating portion, the second sealing layer having one surface adjacent to the other surface of the second cavity layer. , A piezoelectric component sealing the second cavity. 2. A piezoelectric element, a first sealing structure, and a second sealing structure.
And a third sealing structure, wherein the piezoelectric element includes a piezoelectric substrate, at least one front electrode, and at least one back electrode, The front electrode is provided on the front surface of the piezoelectric substrate, the back electrode is provided on the back surface of the piezoelectric substrate, and faces the front electrode, and the front electrode and the back electrode constitute a vibrating portion. Wherein the first sealing structure includes a first hollow layer and a first sealing layer, wherein the first hollow layer includes two first spaced-apart layers. A splitting layer, wherein the first splitting layer has one surface adjacent to the surface of the piezoelectric substrate and forms a first cavity at the interval around the vibrating portion including the front electrode; One sealing layer has one surface adjacent to the other surface of the first division layer, and the second sealing structure has a second surface. A cavity layer and a second sealing layer, wherein the second cavity layer includes two second divided layers arranged at a distance, and the second divided layer has one surface, A second cavity is formed adjacent to the back surface of the piezoelectric substrate and around the vibrating portion including the back electrode, the second cavity being formed by the space, and the second sealing layer has one surface formed of the second divided layer. The third sealing structure is attached to both sides of an assembly including the piezoelectric element, the first sealing structure, and the second sealing structure, The first cavity and the second cavity,
A piezoelectric component sealed on both side surfaces. 3. The piezoelectric component according to claim 1, wherein the front electrode of the piezoelectric element is one, and the first cavity and the second cavity are: Each one is a piezoelectric component. 4. The piezoelectric component according to claim 1, wherein the front electrode of the piezoelectric element is plural, and the first cavity and the second cavity are respectively , A plurality of piezoelectric components. 5. The piezoelectric component according to claim 1, further comprising a base substrate, wherein the base substrate is adjacent to another surface of the second sealing layer. 6. The piezoelectric component according to claim 5, further comprising a top plate, wherein the top plate is adjacent to another surface of the first sealing layer. 7. The piezoelectric component according to claim 6, wherein the piezoelectric substrate, the base substrate, and the top plate have a difference in thermal expansion coefficient between -5 ppm and +5 ppm. parts. 8. The piezoelectric component according to claim 1, wherein the front electrode has a front lead electrode, and an end of the front lead electrode is led to a side edge of the piezoelectric substrate. Conducting to a first terminal electrode provided on a side end surface of the assembly, wherein the back electrode has a back lead electrode, and the back lead electrode has an end portion at a side edge of the piezoelectric substrate. A piezoelectric component which is led out and is electrically connected to a second terminal electrode provided on a side end surface of the assembly. 9. The piezoelectric component according to claim 8, further comprising a connection electrode, wherein the connection electrode causes the first terminal electrode to conduct to the end of the front lead electrode. And a piezoelectric component for conducting the second terminal electrode to the end of the back lead electrode. 10. The piezoelectric component according to claim 9, wherein the front lead electrode and the back lead electrode have a different thickness at the end portion led to a side edge of the piezoelectric substrate. Piezoelectric parts thicker than the part. 11. A method for manufacturing a piezoelectric component, comprising a step of forming a first sealing structure and a second sealing structure, wherein the step of forming the first sealing structure comprises: A first resist resin is applied to the front surface and the back surface of a piezoelectric substrate having a large number of sets of electrodes each consisting of a front electrode and a back electrode opposed to each other so as to individually cover the front electrodes. Thereafter, a first resin layer for a first cavity layer is formed on the surface of the piezoelectric substrate around the first resist resin, and then the first resist resin is removed. To form a hole for each front electrode,
Forming the first sealing layer on the first resin layer, forming the second sealing structure, forming the back electrode on the back surface of the piezoelectric substrate. Apply a second resist resin to cover individually, then
Forming a second resin layer for a second cavity layer on the back surface of the piezoelectric substrate around the second resist resin, and then removing the second resist resin to form the back electrode; Forming a second sealing hole on each of the second resin layers; and forming a second sealing layer on the second resin layer. 12. The manufacturing method according to claim 11, further comprising: bonding a base substrate to the second sealing layer; bonding a top plate to the first sealing layer; Cutting the assembly of the base substrate, the first sealing layer, the first cavity layer, the piezoelectric substrate, the second cavity layer, the second sealing layer, and the top plate. Manufacturing method for piezoelectric components including: 13. The manufacturing method according to claim 12, wherein the step of cutting the assembly includes the steps of:
A method for manufacturing a piezoelectric component, comprising a step of obtaining strip-shaped assemblies arranged in a line. 14. The manufacturing method according to claim 13, wherein after obtaining the strip-shaped assembly, in each of the sets of electrodes, a side end surface of the strip-shaped assembly, A method for manufacturing a piezoelectric component, comprising a step of forming a first terminal electrode that is conductive and a second terminal electrode that is conductive to the back electrode. 15. The manufacturing method according to claim 14, wherein the strip-shaped assembly on which the first terminal electrode and the second terminal electrode are formed is cut to form the electrode. A method for manufacturing a piezoelectric component, comprising a step of dividing each set. 16. A method for manufacturing a piezoelectric component, comprising: forming a first sealing structure and the second sealing structure; wherein forming the first sealing structure is A plurality of pairs of front and back electrodes facing each other on the front and back surfaces of the first hollow layer on the front surface of the piezoelectric substrate provided with a plurality of sets of front and rear electrodes at intervals including a plurality of the front electrodes; Forming a first sealing layer on the first resin layer for forming a first sealing layer on the first resin layer, and then forming the second sealing structure. Forming a second resin layer for a second cavity layer in a band shape on the back surface of the piezoelectric substrate at intervals including a plurality of the back electrodes, and thereafter, forming a second resin layer of the second resin layer. A method for manufacturing a piezoelectric component, comprising a step of forming the second sealing layer thereon. 17. The method for manufacturing a piezoelectric component according to claim 16, wherein the step of forming the first sealing structure includes: forming a plurality of the front electrodes on the surface of the piezoelectric substrate. After applying a first resist resin in a strip shape so as to cover the first resist resin in common, the first resin layer is formed on the surface of the piezoelectric substrate around the first resist resin. 1
Removing the resist resin, and forming a hole including a plurality of the front electrodes, the step of forming the second sealing structure, the back surface of the piezoelectric substrate, the back electrode After applying a second resist resin in a strip shape so as to cover a plurality of the common resists, on the back surface of the piezoelectric substrate around the second resist resin,
A method for manufacturing a piezoelectric component, comprising: forming the second resin layer, and then removing the second resist resin to form a second hole including a plurality of the back electrodes. 18. The manufacturing method according to claim 16, further comprising: bonding a base substrate to the second sealing layer, and attaching a top plate to the first sealing layer. Bonding, and then cutting the assembly of the base substrate, the first sealing structure, the piezoelectric substrate, the second sealing structure, and the top plate. 19. The manufacturing method according to claim 18, wherein the step of cutting the assembly includes the steps of:
A method for manufacturing a piezoelectric component, comprising a step of obtaining strip-shaped assemblies arranged in a line. 20. The manufacturing method according to claim 19, further comprising a step of forming the third sealing structure, wherein the step of forming the third sealing structure includes the step of: A method of manufacturing a piezoelectric component, comprising: attaching a third sealing layer to both side surfaces of a strip-shaped assembly, and sealing the first cavity and the second cavity at the both side surfaces. 21. The manufacturing method according to claim 20, wherein the strip-shaped assembly on which the third sealing layer is formed is connected to the front electrode in each of the sets of electrodes. 1
And forming a second terminal electrode electrically connected to the back electrode. 22. The manufacturing method according to claim 21, wherein the strip-shaped assembly on which the first terminal electrode and the second terminal electrode are formed is cut to form the electrode. A method for manufacturing a piezoelectric component, comprising a step of dividing each set.