TWI823401B - Piezoelectric vibration plate and piezoelectric vibration device - Google Patents

Abstract

The piezoelectric vibrating plate (10) includes a vibrating part (11), an outer frame part (12) surrounding the outer periphery of the vibrating part (11), and a holding part (13) connecting the vibrating part (11) and the outer frame part (12). ), flat portions (13a, 13b) are respectively provided on a pair of main surface portions facing each other of the holding portion (13), that is, the first main surface portion and the second main surface portion. One flat portion (13b) is located on the holding portion. The width of (13) in the width direction is larger than the width of the other flat portion (13a) in the width direction of the holding portion (13).

Description

Piezoelectric vibration plate and piezoelectric vibration device

The present invention relates to a piezoelectric vibration plate and a piezoelectric vibration device provided with the piezoelectric vibration plate.

In recent years, the operating frequencies of various electronic devices have been increased and packages have been miniaturized (especially low-profile). Therefore, as the frequency increases and packages become smaller, piezoelectric vibration devices (such as crystal vibrators, crystal oscillators, etc.) are required to cope with the increase in frequency and the miniaturization of packages.

The housing of such a piezoelectric vibration device is composed of a substantially rectangular parallelepiped package. The package includes a first sealing member and a second sealing member made of, for example, glass or crystal, and a piezoelectric vibration plate made of, for example, crystal, with excitation electrodes formed on both main surfaces. The first sealing member and the second sealing member The piezoelectric vibration plates are laminated and bonded. Furthermore, the vibrating portion (excitation electrode) of the piezoelectric vibrating plate arranged inside the package (inner space) is hermetically sealed (for example, Patent Document 1). Hereinafter, such a stacked form of piezoelectric vibration devices will be referred to as a sandwich structure.

In the piezoelectric vibration device as described above, the piezoelectric vibration plate includes a vibrating portion, an outer frame portion surrounding the outer periphery of the vibrating portion, and a holding portion (bridge portion) connecting the vibrating portion and the outer frame portion. That is, the piezoelectric vibrating plate has a structure in which the vibration part, the holding part and the outer frame part are integrated through a piezoelectric substrate made of crystal or the like. However, there is a problem that the piezoelectric vibrating plate is easily broken at the holding portion. The reason is that when the piezoelectric vibrating plate is wet-etched, a thin area is formed on the side surface of the holding portion.

[Patent Document 1]: Japanese Patent Application Publication No. 2010-252051

In view of the above circumstances, it is an object of the present invention to provide a piezoelectric vibration plate capable of preventing breakage at a holding portion, and a piezoelectric vibration device including the piezoelectric vibration plate.

As a technical solution to solve the above technical problems, the present invention has the following structure. That is, the present invention is a piezoelectric vibrating plate including a vibrating part, an outer frame surrounding the outer periphery of the vibrating part, and a holding part connecting the vibrating part and the outer frame, wherein the holding part A pair of main surface portions facing each other, that is, a first main surface portion and a second main surface portion are respectively provided with a flat portion, and one of the flat portion of the first main surface portion and the flat portion of the second main surface portion is provided with a flat portion. The width of one flat portion in the width direction of the holding portion is greater than the width of the other flat portion in the width direction of the holding portion.

According to the above structure, when the piezoelectric vibrating plate is wet-etched, the thin region formed at one end in the width direction of the holding portion can be reduced, thereby ensuring the strength of the holding portion. This can prevent the holding portion of the piezoelectric diaphragm from being broken.

Furthermore, the present invention is a piezoelectric vibrating plate including a vibrating part, an outer frame part surrounding the outer periphery of the vibrating part, and a holding part connecting the vibrating part and the outer frame part, wherein the holding part A pair of main surface portions facing each other, that is, a first main surface portion and a second main surface portion are respectively provided with a flat portion, and one of the flat portion of the first main surface portion and the flat portion of the second main surface portion is provided with a flat portion. One end of the flat portion in the width direction of the holding portion is closer to the one end side in the width direction than the other flat portion.

Based on the above structure, when the piezoelectric vibrating plate is wet-etched, the thin region formed at one end in the width direction of the holding portion can be reduced, thereby ensuring the strength of the holding portion. This can prevent the holding portion of the piezoelectric diaphragm from being broken.

In the above-mentioned structure, it is preferable that the other ends of the flat portions of the first main surface portion and the second main surface portion in the width direction of the holding portion are provided in the width direction of the holding portion. Roughly the same location.

In addition, in the above structure, it is preferable that the piezoelectric vibration plate is an AT-cut crystal piece, the first main surface part and the second main surface part are arranged parallel to the AT-cut XZ ' plane, and the first main surface part is The main surface is provided on the +Y direction side, and the second main surface is provided on the -Y direction side. In this case, it is preferable that only one holding portion is provided and the holding portion extends from the corner portion of the vibration portion on the +X direction side and the -Z ' direction side to the -Z ' direction side.

Furthermore, the present invention is a piezoelectric vibration device including a piezoelectric vibration plate adopting any of the above structures, including a first sealing member covering one main surface side of the vibration portion of the piezoelectric vibration plate, and A second sealing member covering the other main surface side of the vibration portion of the piezoelectric vibration plate is joined to the piezoelectric vibration plate through the first sealing member, and the second sealing member is bonded to the piezoelectric vibration plate. The piezoelectric vibration plates are joined, and the vibration portion of the piezoelectric vibration plates is sealed.

The chip piezoelectric vibration device based on the crystal vibration having the above structure can obtain the same effects as the above-mentioned piezoelectric vibration plate. That is, when a piezoelectric vibration plate with a frame is used, in which the vibration part and the outer frame part are connected through the holding part, not only the size and height of the piezoelectric vibration device can be reduced, but also such miniaturization can be achieved. In a thinner piezoelectric vibration device, the holding portion of the piezoelectric vibration plate can be prevented from being broken.

Based on the present invention, it is possible to provide a piezoelectric vibration plate that can prevent breakage at the holding portion, and a piezoelectric vibration device including the piezoelectric vibration plate.

10: Piezoelectric vibration plate (crystal vibration plate)

11:Vibration Department

12:Outer frame part

13:Maintenance Department

13a, 13b: flat part

13c, 13d, 13f: inclined part

13e: Right angle part

13g: Incision part

100: Crystal oscillator (piezoelectric vibration device)

10a: Penetration Department

101, 201, 301: first main surface

102, 202, 302: Second main surface

111: First excitation electrode

112: Second excitation electrode

113: First lead wiring

114: Second lead wiring

115, 116: Sealed path

121, 24: First joint pattern

122, 31: Second joint pattern

123, 124, 14, 15, 25, 261, 261, 262, 263, 34: joint pattern

161: First through hole

162: Second through hole

20: First sealing member

22:First terminal

23: Second terminal

27: Wiring pattern

28:Metal film

211:Third through hole

212: The fourth through hole

213:Fifth through hole

30: Second sealing member

32:External electrode terminal

33: The sixth through hole

The details of one or more embodiments of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects and advantages of the subject matter of this specification will become apparent from the description, drawings and claims, among which:

FIG. 1 is a schematic structural diagram schematically showing each component of the crystal oscillator according to this embodiment.

2 is a schematic plan view of the first main surface side of the first sealing member of the crystal resonator.

3 is a schematic plan view of the second main surface side of the first sealing member of the crystal resonator.

4 is a schematic plan view of the first main surface side of the piezoelectric vibrating plate according to this embodiment.

FIG. 5 is a schematic plan view of the second main surface side of the piezoelectric vibrating plate according to this embodiment.

6 is a schematic plan view of the first main surface side of the second sealing member of the crystal resonator.

7 is a schematic plan view of the second main surface side of the second sealing member of the crystal resonator.

FIG. 8 is a cross-sectional view taken along line A1-A1 in FIG. 4 .

FIG. 9 is a diagram corresponding to FIG. 8 showing the piezoelectric vibrating plate according to Modification 1. FIG.

FIG. 10 is a diagram equivalent to FIG. 8 showing a piezoelectric vibrating plate according to Modification 2. FIG.

FIG. 11 is a diagram corresponding to FIG. 8 showing a piezoelectric vibrating plate according to Modification 3. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, a case will be described in which the piezoelectric vibration device to which the present invention is applied is a crystal oscillator.

First, the basic structure of the crystal oscillator 100 of this embodiment will be described. As shown in FIG. 1 , the crystal oscillator 100 has a structure including a piezoelectric vibrating plate (crystal vibrating plate) 10 , a first sealing member 20 , and a second sealing member 30 . In this crystal oscillator 100, the piezoelectric vibrating plate 10 is joined to the first sealing member 20, and the piezoelectric vibrating plate 10 is joined to the second sealing member 30 to form an approximately rectangular parallelepiped. sandwich structure package. That is, in the crystal oscillator 100 , the first sealing member 20 and the second sealing member 30 are respectively joined to both main surfaces of the piezoelectric vibrating plate 10 to form an internal space (cavity) of the package, and the vibrating portion 11 (see Figure 4, Figure 5) is hermetically sealed in the internal space.

The crystal oscillator 100 of this embodiment has a package size of, for example, 1.0×0.8 mm, achieving miniaturization and low profile. In addition, due to miniaturization, castellation is not formed in the package, and conduction of the electrodes is achieved by using through holes described later. In addition, the crystal oscillator 100 is electrically connected to an external circuit board (not shown) provided outside through solder.

Next, each component of the piezoelectric vibrating plate 10, the first sealing member 20, and the second sealing member 30 in the crystal oscillator 100 will be described with reference to FIGS. 1 to 7 . In addition, the description here is for each member that has not been joined and has a single-piece structure. FIGS. 2 to 7 only show one structural example of each of the piezoelectric vibration plate 10 , the first sealing member 20 , and the second sealing member 30 , and they are not intended to limit the present invention.

As shown in FIGS. 4 and 5 , the piezoelectric vibrating plate 10 of this embodiment is a piezoelectric substrate made of crystal, and its two main surfaces (first main surface 101 , second main surface 102 ) are processed (mirror surface processing). ) is a flat smooth surface. In this embodiment, an AT-cut quartz crystal that undergoes thickness sliding vibration is used as the piezoelectric vibration plate 10 . In the piezoelectric vibrating plate 10 shown in FIGS. 4 and 5 , the two main surfaces (the first main surface 101 and the second main surface 102 ) of the piezoelectric vibrating plate 10 are XZ ' planes. In the XZ ' plane, the direction parallel to the width direction (short side direction) of the piezoelectric vibrating plate 10 is the X-axis direction, and the direction parallel to the length direction (long side direction) of the piezoelectric vibrating plate 10 is the Z ' axis direction. . In addition, AT cut refers to the three crystal axes of the artificial crystal, that is, the electrical axis (X axis), the mechanical axis (Y axis) and the optical axis (Z axis). The X axis circumferential direction is tilted relative to the Z axis. Processing method of cutting at an angle of 35°15 ' . In AT-cut crystal pieces, the X-axis is consistent with the crystal axis of the crystal. The Y ' and Z ' axes are approximately 35°15 ' each from the Y and Z axes of the crystal axis of the crystal (the cutting angle can be slightly changed within the range of adjusting the frequency and temperature characteristics of the AT-cut piezoelectric vibrating plate) And the resulting axes are consistent. The Y' - axis direction and the Z' - axis direction are equivalent to the cutting directions when cutting AT-cut crystal wafers.

A pair of excitation electrodes (first excitation electrode 111 , second excitation electrode 112 ) is formed on the two main surfaces (first main surface 101 , second main surface 102 ) of the piezoelectric vibrating plate 10 . The piezoelectric vibrating plate 10 has a substantially rectangular vibrating part 11, an outer frame part 12 surrounding the outer periphery of the vibrating part 11, and a holding part ( Bridge Department)13. That is, the piezoelectric vibrating plate 10 has a structure in which the vibrating part 11 , the outer frame part 12 and the holding part 13 are integrated. The holding portion 13 extends (projects) toward the −Z′ direction from only one corner portion of the vibrating portion 11 located in the +X direction and the −Z′ direction to the outer frame portion 12 . Furthermore, between the vibrating part 11 and the outer frame part 12, a penetration part (slit) 10a is provided which penetrates the piezoelectric vibrating plate 10 in the thickness direction. In this embodiment, the piezoelectric vibrating plate 10 is provided with only one holding portion 13 that connects the vibrating portion 11 and the outer frame portion 12 , and the through portion 10 a is configured to continuously surround the outer periphery of the vibrating portion 11 . The cross-sectional shape of the holding portion 13 will be described in detail later.

The first excitation electrode 111 is provided on the first main surface 101 side of the vibrating part 11 , and the second excitation electrode 112 is provided on the second main surface 102 side of the vibrating part 11 . The first excitation electrode 111 and the second excitation electrode 112 are connected with input/output lead wires (the first lead wire 113 and the second lead wire 114 ) for connecting these excitation electrodes to external electrode terminals. The first lead-out wiring 113 on the input side is led out from the first excitation electrode 111 and connected to the connection bonding pattern 14 formed on the outer frame portion 12 via the holding portion 13 . The second lead-out wiring 114 on the output side is led out from the second excitation electrode 112 and connected to the connection bonding pattern 15 formed on the outer frame portion 12 via the holding portion 13 .

On the two main surfaces (the first main surface 101 and the second main surface 102 ) of the piezoelectric vibrating plate 10 , there are respectively provided the piezoelectric vibrating plate 10 with the first sealing member 20 and the second sealing member 30 . Diaphragm side seal. As the diaphragm side sealing portion of the first main surface 101, a diaphragm side first contact is formed. Joining pattern 121; a diaphragm-side second joining pattern 122 is formed as the diaphragm-side sealing portion of the second main surface 102. The first bonding pattern 121 on the diaphragm side and the second bonding pattern 122 on the diaphragm side are provided on the outer frame portion 12 and are configured in an annular shape when viewed from above.

In addition, as shown in FIGS. 4 and 5 , the piezoelectric vibrating plate 10 is formed with five through holes penetrating between the first main surface 101 and the second main surface 102 . Specifically, the four first through holes 161 are respectively provided in the areas of the four corners (corner portions) of the outer frame portion 12 . The second through hole 162 is provided on one side of the vibrating part 11 in the Z ′ axis direction of the outer frame part 12 (the −Z ′ direction side in FIGS. 4 and 5 ). Connection bonding patterns 123 are respectively formed around the first through holes 161 . In addition, around the second through hole 162 , a connection joint pattern 124 is formed on the first main surface 101 side, and a connection joint pattern 15 is formed on the second main surface 102 side.

In the first through hole 161 and the second through hole 162, a through electrode for connecting the electrode formed on the first main surface 101 and the electrode formed on the second main surface 102 is formed along the inner wall surface of each of the through hole. In addition, the intermediate portions of each of the first through hole 161 and the second through hole 162 serve as hollow through portions that penetrate between the first main surface 101 and the second main surface 102 . The outer peripheral edge of the first bonding pattern 121 on the diaphragm side is provided close to the outer peripheral edge of the first main surface 101 of the piezoelectric diaphragm 10 (outer frame portion 12 ). The outer peripheral edge of the second bonding pattern 122 on the diaphragm side is provided close to the outer peripheral edge of the second main surface 102 of the piezoelectric diaphragm 10 (outer frame portion 12 ). In addition, in this embodiment, an example in which five through holes are formed penetrating between the first main surface 101 and the second main surface 102 is explained. However, the piezoelectric vibrating plate 10 may be formed without forming the through holes. A part of the side surface is cut off, and a castellation with an electrode attached is formed on the inner wall surface of the cut area (the same is true for the first sealing member 20 and the second sealing member 30 ).

As shown in FIGS. 2 and 3 , the first sealing member 20 is a rectangular parallelepiped substrate formed from an AT-cut crystal. The second main surface 202 of the first sealing member 20 (the surface bonded to the piezoelectric vibration plate 10 ) is Processing (mirror processing) is a flat and smooth surface. In addition, the first sealing member 20 does not have a vibrating portion, but by using an AT-cut crystal like the piezoelectric vibrating plate 10 , the thermal expansion coefficient of the piezoelectric vibrating plate 10 is made the same as that of the first sealing member 20 , thereby suppressing Thermal deformation of the crystal oscillator 100. In addition, the directions of the X-axis, Y-axis, and Z′ - axis of the first sealing member 20 are also the same as those of the piezoelectric vibration plate 10 .

As shown in FIG. 2 , on the first main surface 201 (the outer main surface not facing the piezoelectric vibration plate 10 ) of the first sealing member 20 , first terminals 22 and second terminals 23 for wiring are formed. and a metal film 28 for shielding (grounding). The first terminal 22 and the second terminal 23 for wiring are provided as wiring for electrically connecting the first excitation electrode 111 and the second excitation electrode 112 of the piezoelectric vibration plate 10 and the external electrode terminal 32 of the second sealing member 30 . The first terminal 22 and the second terminal 23 are provided at both ends in the Z ' axis direction. The first terminal 22 is provided on the +Z ' direction side, and the second terminal 23 is provided on the -Z ' direction side. The first terminal 22 and the second terminal 23 are configured to extend in the X-axis direction. The first terminal 22 and the second terminal 23 are configured in an approximately rectangular shape.

The metal film 28 is provided between the first terminal 22 and the second terminal 23 and is arranged at a predetermined distance from the first terminal 22 and the second terminal 23 . The metal film 28 is provided on almost the entire area of the first main surface 201 of the first sealing member 20 where the first terminal 22 and the second terminal 23 are not formed. The metal film 28 extends from the +X-direction end of the first main surface 201 of the first sealing member 20 to the -X-direction end.

As shown in FIGS. 2 and 3 , six through holes penetrating between the first main surface 201 and the second main surface 202 are formed in the first sealing member 20 . Specifically, four third through holes 211 are provided in the areas of the four corners (corner portions) of the first sealing member 20 . The fourth through hole 212 and the fifth through hole 213 are respectively provided in the +Z ' direction and -Z ' direction in FIGS. 2 and 3 .

In the third through hole 211, the fourth through hole 212, and the fifth through hole 213, an electrode formed on the first main surface 201 and the electrode formed on the second main surface 202 are formed along the inner wall surface of each through hole. The electrode conducts through the electrode. In addition, the middle portions of each of the third through hole 211 , the fourth through hole 212 , and the fifth through hole 213 become hollow through portions that penetrate between the first main surface 201 and the second main surface 202 . Furthermore, the two third through holes 211 located at diagonal corners of the first main surface 201 of the first sealing member 20 (the third through holes located at the corners of the +X direction and the +Z ' direction in FIGS. 2 and 3 211, and the third through-hole 211) located at the corner of the −X direction and the −Z ′ direction are electrically connected to each other through the metal film 28. In addition, the through electrodes of the third through hole 211 and the through electrodes of the fourth through hole 212 located at the corners of the −X direction and the +Z ′ direction are electrically connected through the first terminal 22 . The through electrodes of the third through hole 211 and the through electrodes of the fifth through hole 213 located at the corners of the +X direction and the −Z ′ direction are electrically connected through the second terminal 23 .

On the second main surface 202 of the first sealing member 20 , a sealing member side first bonding pattern 24 is formed as a sealing member side first sealing portion bonded to the piezoelectric vibration plate 10 . The sealing member side first bonding pattern 24 is configured in an annular shape when viewed from above. In addition, on the second main surface 202 of the first sealing member 20 , connection joint patterns 25 are respectively formed around the third through holes 211 . A connection joint pattern 261 is formed around the fourth through hole 212 , and a connection joint pattern 262 is formed around the fifth through hole 213 . Furthermore, a connection joint pattern 263 is formed on the side opposite to the long axis direction of the first sealing member 20 (-Z ' direction side) with respect to the connection joint pattern 261, and the connection joint pattern 261 and the connection joint pattern 263 are formed. They are connected via wiring patterns 27 . The outer peripheral edge of the first joint pattern 24 on the sealing member side is disposed close to the outer peripheral edge of the second main surface 202 of the first sealing member 20 .

As shown in FIGS. 6 and 7 , the second sealing member 30 is a rectangular parallelepiped substrate composed of an AT-cut crystal. The first main surface 301 of the second sealing member 30 (the surface bonded to the piezoelectric vibration plate 10 ) The processed (mirror surface) is a flat and smooth surface. In addition, the second sealing member 30 also uses an AT-cut crystal like the piezoelectric vibration plate 10 . Preferably, the directions of the X-axis, Y-axis, and Z ′ are the same as those of the piezoelectric vibration plate 10 .

On the first main surface 301 of the second sealing member 30 , a second sealing member-side bonding pattern 31 is formed as a second sealing member-side sealing portion for bonding to the piezoelectric vibrating plate 10 . The sealing member side second bonding pattern 31 is configured in an annular shape when viewed from above. The outer peripheral edge of the second joint pattern 31 on the sealing member side is disposed close to the outer peripheral edge of the first main surface 301 of the second sealing member 30 .

On the second main surface 302 of the second sealing member 30 (the outer main surface not facing the piezoelectric vibrating plate 10 ), four circuit boards for electrically connecting to an external circuit board provided outside the crystal oscillator 100 are provided. External electrode terminal 32. The external electrode terminals 32 are respectively located at the four corners (corner portions) of the second main surface 302 of the second sealing member 30 .

As shown in FIGS. 6 and 7 , four through holes penetrating between the first main surface 301 and the second main surface 302 are formed in the second sealing member 30 . Specifically, four sixth through holes 33 are provided in the areas of the four corners (corner portions) of the second sealing member 30 . In the sixth through-holes 33 , through-electrodes for connecting the electrodes formed on the first main surface 301 and the electrodes formed on the second main surface 302 are formed along respective inner wall surfaces of the sixth through-holes 33 . In this way, the electrode formed on the first main surface 301 is electrically connected to the external electrode terminal 32 formed on the second main surface 302 through the through electrode formed on the inner wall surface of the sixth through hole 33 . In addition, the middle portions of each of the sixth through holes 33 serve as hollow through portions that penetrate between the first main surface 301 and the second main surface 302 . In addition, on the first main surface 301 of the second sealing member 30 , connection joint patterns 34 are respectively formed around the sixth through holes 33 .

In the crystal oscillator 100 including the piezoelectric vibration plate 10, the first sealing member 20, and the second sealing member 30, the piezoelectric vibration plate 10 and the first sealing member 20 are first joined on the vibration plate side. The pattern 121 and the sealing member side first bonding pattern 24 are diffusion bonded in a state where they overlap; the piezoelectric vibration plate 10 and the second sealing member 30 overlap with the vibration plate side second bonding pattern 122 and the sealing member side second bonding pattern 31. Diffusion bonding is performed in the state to form a sandwich structure package shown in Figure 1 . Thereby, the internal space of the package, that is, the accommodation space of the vibrating part 11 is hermetically sealed.

At this time, the above-described connecting bonding patterns are also diffusion bonded in an overlapping state. In this way, the first excitation electrode 111 , the second excitation electrode 112 , and the external electrode terminal 32 in the crystal resonator 100 can be electrically connected through the bonding between the connection bonding patterns. Specifically, the first excitation electrode 111 passes through the first lead-out wiring 113, the wiring pattern 27, the fourth through hole 212, the first terminal 22, the third through hole 211, the first through hole 161, and the sixth through hole 33. Connected to external electrode terminal 32. The second excitation electrode 112 communicates with the outside via the second lead-out wiring 114 , the second through hole 162 , the fifth through hole 213 , the second terminal 23 , the third through hole 211 , the first through hole 161 , and the sixth through hole 33 in sequence. The electrode terminals 32 are connected. In addition, the metal film 28 is grounded via the third through hole 211 , the first through hole 161 , and the sixth through hole 33 in this order (grounded by a part of the external electrode terminal 32 ).

In the crystal oscillator 100, it is preferable that each bonding pattern is composed of a plurality of layers stacked on a crystal piece, and that a Ti (titanium) layer and an Au (gold) layer are formed by evaporation or sputtering from the lowest layer side. layer. In addition, it is preferable that other wirings and electrodes formed on the crystal resonator 100 also have the same structure as the bonding pattern, so that the bonding patterns, wirings, and electrodes can be patterned simultaneously.

In the crystal oscillator 100 having the above-mentioned structure, the sealing portion (the sealing path 115 and the sealing path 116 ) that hermetically seals the vibrating portion 11 of the piezoelectric vibrating plate 10 is configured in an annular shape in plan view. The sealing path 115 is formed by diffusion bonding (Au-Au bonding) of the diaphragm side first bonding pattern 121 and the sealing member side first bonding pattern 24, and the outer edge shape and the inner edge shape of the sealing path 115 are configured as follows Approximately octagonal. Likewise, the sealing path 116 is formed by passing the second bonding pattern 122 on the diaphragm side and The sealing member side second bonding pattern 31 is formed by diffusion bonding (Au-Au bonding), and the outer edge shape and the inner edge shape of the sealing path 116 are configured to be approximately octagonal.

As described above, in the crystal oscillator 100 in which the sealing path 115 and the sealing path 116 are formed by diffusion bonding, there is a gap of 1.00 μm or less between the first sealing member 20 and the piezoelectric vibrating plate 10 , and the second sealing member 30 and the piezoelectric vibrating plate 10 have a gap of 1.00 μm or less. There is a gap of 1.00 μm or less between the diaphragms 10 . In other words, the thickness of the sealing path 115 between the first sealing member 20 and the piezoelectric vibration plate 10 is 1.00 μm or less, and the thickness of the sealing path 116 between the second sealing member 30 and the piezoelectric vibration plate 10 is 1.00 μm or less ( Specifically, in the case of Au-Au bonding in this embodiment, it is 0.15 μm to 1.00 μm). In addition, as a comparative example, when a conventional metal paste sealing material of Sn (tin) is used, the thickness is 5 μm to 20 μm.

Hereinafter, the piezoelectric vibrating plate 10 of this embodiment will be described with reference to FIGS. 4 , 5 , and 8 .

As shown in FIGS. 4 and 5 , the piezoelectric vibrating plate 10 includes a vibrating part 11 formed in a substantially rectangular shape, an outer frame part 12 surrounding the outer periphery of the vibrating part 11 , and a holding part connecting the vibrating part 11 and the outer frame part 12 13. The holding part 13 has a cross-sectional shape as shown in FIG. 8 .

Specifically, as shown in FIG. 8 , the first main surface part and the second main surface part facing each other of the holding part 13 are arranged parallel to the XZ ′ plane of the AT cut, and the first main surface part is arranged on the +Y direction side. The second main surface is a surface provided on the -Y direction side. The width direction of the holding portion 13 is parallel to the X-axis direction. In addition, illustration of the first lead wiring 113 and the second lead wiring 114 formed on the first main surface part and the second main surface part of the holding part 13 is omitted in FIG. 8 .

Furthermore, flat portions 13a and 13b are respectively provided on the first main surface portion and the second main surface portion facing each other of the holding portion 13 to form surfaces parallel to the XZ ' plane. Among the flat portion 13a of the first main surface and the flat portion 13b of the second main surface, one of the flat portions (the flat portion of the second main surface) 13b is wider in the width direction of the holding portion 13 than the other flat portion ( The width of the flat portion (flat portion) 13a of the first main surface portion in the width direction of the holding portion 13. In addition, one end of the flat portion (the flat portion of the second main surface) 13b in the width direction of the holding portion 13 (the −X direction) is smaller than the other flat portion (the flat portion of the first main surface) 13a. side) closer to one end (-X direction side) of the holding portion 13 in the width direction. The flat portion 13 a of the first main surface portion is at the other end in the width direction of the holding portion 13 (the end on the +X direction side) and the flat portion 13 b of the second main surface portion is at the other end in the width direction of the holding portion 13 (the +X direction side). direction side) are provided at substantially the same position in the width direction of the holding portion 13 .

On the first main surface side of the holding part 13, one end in the width direction of the flat part 13a (one end on the -X direction side) is connected to an inclined part 13c, and the inclined part 13c is inclined at a predetermined angle to the flat part 13a; the flat part 13a The other end in the width direction (the end on the +X direction side) is connected to an inclined portion 13d that is inclined at a predetermined angle with respect to the flat portion 13a.

On the second main surface side of the holding part 13, one end in the width direction of the flat part 13b (one end on the -X direction side) is connected to a right-angled part 13e, which is perpendicular to the flat part 13b, and is incline with the right-angled part 13e. The other end in the width direction of the flat part 13b (one end on the +X direction side) is connected to the inclined part 13f, and the inclined part 13f is inclined at a predetermined angle to the flat part 13b, and the inclined part 13f and the inclined part 13d connection.

In this embodiment, the cross-sectional shape of the holding portion 13 is surrounded by a flat portion 13a, an inclined portion 13c, and an inclined portion 13d on the first main surface side, and a flat portion 13b, a right-angled portion 13e, and an inclined portion 13f on the second main surface side. into shape. Furthermore, the width of the flat portion 13 b of the second main surface portion in the width direction of the holding portion 13 is larger than the width of the flat portion 13 a of the first main surface portion in the width direction of the holding portion 13 . In addition, one end of the flat portion 13 b of the second main surface portion in the width direction of the holding portion 13 is closer to one end of the width direction of the holding portion 13 than the one end of the flat portion 13 a of the first main surface portion in the width direction of the holding portion 13 . end. Such a cross-sectional shape of the holding portion 13 can be achieved by setting the width of the holding portion 13 to have a difference between the first main surface portion and the second main surface portion in the mask design stage when wet etching the piezoelectric vibrating plate 10 . And formed. For example, the width of the mask of the second main surface part may be approximately 20 to 30 μm larger than the width of the mask of the first main surface part.

According to this embodiment, it is possible to prevent the holding portion 13 of the piezoelectric vibrating plate 10 from being broken. Specifically, when the piezoelectric vibrating plate 10 is wet-etched, the thin region (for example, the notch shown in FIG. 9 ) formed on one end side (-X direction side) of the holding portion 13 in the width direction can be reduced. part (contraction part) 13g). In this case, for example, as shown in FIG. 10 , since the width L1 of the notch portion 13 g in the X-axis direction is reduced, the thin region formed on one end side (-X direction side) of the holding portion 13 in the width direction can be reduced. Small, the strength of the holding part 13 can be ensured. This can prevent the holding portion 13 of the piezoelectric vibrating plate 10 from being broken.

In addition, FIG. 8 shows a state in which the cutout portion 13g is not formed in the holding portion 13 and the width L1 of the cutout portion 13g in the X-axis direction is zero. In order to prevent the holding portion 13 of the piezoelectric vibrating plate 10 from being broken, it is preferable to form the holding portion 13 as shown in FIG. 8 .

On the other hand, FIGS. 9 and 10 show a state in which the cutout portion 13g having a substantially rectangular cross-sectional shape is formed on the second main surface side of the holding portion 13. The strength of the holding portion 13 is weakened by the cutout portion 13g. However, in this embodiment, the width of the flat portion 13b of the second main surface portion in the width direction of the holding portion 13 is larger than the width of the flat portion 13a of the first main portion in the width direction of the holding portion 13; the second main surface portion The flat portion 13b is closer to one end of the holding portion 13 in the width direction than the flat portion 13a of the first main surface portion is located closer to one end of the holding portion 13 in the width direction. The flat portion 13b of the second main surface portion provided with the notch portion 13g is longer than the flat portion 13a of the first main surface portion not provided with the notch portion. In addition, one end of the flat portion 13b of the second main surface portion provided with the cutout portion 13g is smaller than the flat portion 13b without the cutout portion 13g. One end of the flat portion 13 a of the first main surface portion of the cutout portion is closer to one end of the holding portion 13 in the width direction. Thereby, the width L1 of the notch part 13g in the X-axis direction can be further reduced and it can approach the holding part shape of FIG. 8, and the strength of the holding part 13 can be ensured by the part of the notch part 13g. This can prevent the holding portion 13 of the piezoelectric vibrating plate 10 from being broken.

In this embodiment, the piezoelectric vibrating plate 10 is configured to include a vibrating part 11, an outer frame part 12 surrounding the outer periphery of the vibrating part 11, and a holding part (bridge part) connecting the vibrating part 11 and the outer frame part 12. 13, and a penetrating portion 10a penetrating in the thickness direction is provided between the vibrating portion 11 and the outer frame portion 12. When using such a framed piezoelectric vibrating plate 10 in which the vibrating part 11 and the outer frame part 12 are connected by the holding part 13, not only the size and height of the crystal oscillator 100 can be reduced, but also such a small size can be achieved. The smaller and thinner crystal oscillator 100 can prevent the holding portion 13 of the piezoelectric vibrating plate 10 from being broken.

However, in the piezoelectric vibrating plate 10 used for high frequencies (for example, 60 to 80 MHz), in order to cope with the increase in frequency, the thickness of the vibrating portion 11 of the piezoelectric vibrating plate 10 is formed thin, and the thickness of the holding portion 13 also becomes smaller. Thin. Therefore, it is difficult to stably form the shape of the holding portion 13 shown in FIG. 8 by wet etching.

However, as shown in FIG. 11 , by forming the end portion of the holding portion 13 in the −X direction into a shape in which the thickness continuously changes, the holding portion 13 can be formed stably, and the strength of the holding portion 13 can be ensured. Therefore, in the crystal oscillator 100 that supports higher frequencies, it is possible to prevent the holding portion 13 of the piezoelectric vibrating plate 10 from being broken.

The holding part 13 shown in FIG. 11 has a shape in which the right-angled part 13e of the holding part 13 shown in FIG. 8 is not provided. The cross-sectional shape of the holding portion 13 is a shape surrounded by the flat portion 13a, the inclined portion 13c, and the inclined portion 13d on the first main surface side, and the flat portion 13b and the inclined portion 13f on the second main surface side. The flat part 13b is connected to the inclined part 13c.

Furthermore, among the flat portion 13a of the first main surface and the flat portion 13b of the second main surface, one of the flat portions (the flat portion of the second main surface) 13b has a wider width in the width direction of the holding portion 13 than the other flat portion. (the flat portion of the first main surface portion) 13 a in the width direction of the holding portion 13 . In addition, one end of the flat portion (the flat portion of the second main surface) 13b in the width direction of the holding portion 13 (the −X direction) is smaller than the other flat portion (the flat portion of the first main surface) 13a. side) closer to one end (-X direction side) of the holding portion 13 in the width direction. In the width direction of the holding portion 13 , the flat portion 13 a of the first main surface portion and the flat portion 13 b of the second main surface portion are each provided at approximately the other end (one end on the +X direction side) of the holding portion 13 in the width direction. Same location.

In the piezoelectric vibrating plate 10 used for high frequency (for example, 60 to 80 MHz), the thickness of the holding portion 13 is, for example, 30 μm, and the flat portion 13 b of the second main surface portion is smaller at one end on the −X direction side than the flat portion of the first main surface portion. One end of 13a on the -X direction side is closer to the -X direction side, that is, it grows by 10 to 20 μm, for example. In other words, the distance L2 in Figure 11 is 10~20 μm.

The embodiments disclosed this time are examples of various aspects and do not constitute a basis for restrictive interpretation. Therefore, the technical scope of the present invention cannot be interpreted solely based on the above-described embodiments, but must be defined based on the description of the claims. In addition, all changes within the meaning and scope of the requested items are included.

In the above embodiment, only one holding part (bridge part) 13 for connecting the vibrating part 11 and the outer frame part 12 is provided on the piezoelectric vibrating plate 10. However, two or more holding parts 13 may be provided. Here, In this case, each holding portion 13 may adopt the structure of the above embodiment.

In the above embodiment, the thickness of the vibrating portion 11 and the holding portion 13 of the piezoelectric vibrating plate 10 may be smaller than the thickness of the outer frame portion 12 .

In the above embodiment, the first sealing member 20 and the second sealing member 30 are composed of crystal plates, but the present invention is not limited thereto. The first sealing member 20 and the second sealing member 30 may also be composed of crystal plates, for example. Made of glass. In addition, they are not limited to brittle materials such as crystal and glass. The first sealing member 20 and the second sealing member 30 may also be composed of a resin plate, a resin film, or the like. In this case, the vibrating part 11 can be sealed by attaching a resin plate, a resin film, or the like to the piezoelectric vibrating plate 10 .

In the above embodiment, a sandwich-structured crystal oscillator in which the piezoelectric vibrating plate 10 is sandwiched between the first sealing member 20 and the second sealing member 30 is used as the crystal oscillator 100 . However, crystal oscillators with other structures may also be used. sub 100. For example, a crystal oscillator having a recess, housing the piezoelectric vibrating plate 10 inside a base made of an insulating material such as ceramic, glass, or quartz, and having a cover joined to the base can be used.

In the above embodiment, the number of external electrode terminals 32 on the second main surface 302 of the second sealing member 30 is four, but it is not limited thereto. The number of external electrode terminals 32 may be, for example, two, six or eight. wait. In addition, in the above-mentioned embodiment, the case where the present invention is applied to the crystal oscillator 100 has been described. However, the present invention is not limited to this. For example, the present invention may also be applied to a crystal oscillator.

This application claims priority based on Japanese Patent Application No. 2021-091598 filed in Japan on May 31, 2021. It goes without saying that all its contents are incorporated into this application.

As used herein and not otherwise defined, the terms "substantially" and "approximately" are used to describe and describe small changes. When used in connection with an event or situation, the term may include the precise moment at which the event or situation occurs, as well as the event or situation occurring to a close approximation. For example, when combined with a numerical value, the term may include a range of variation less than or equal to ±10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%.

The components of several embodiments are summarized above so that those with ordinary skill in the technical field to which the present invention belongs can better understand the concepts of the embodiments of the present invention. In the technical field to which the present invention belongs, there are It should be understood by those of ordinary skill that other processes and structures may be designed or modified using the embodiments of the present invention as a basis to achieve the same purposes and/or achieve the same benefits as the embodiments introduced herein. Those with ordinary skill in the technical field to which the present invention belongs should also understand that these equivalent structures do not deviate from the spirit and scope of the present invention, and that various modifications can be made without departing from the spirit and scope of the present invention. Changes, Substitutions and Alternatives. Therefore, the protection scope of the present invention shall be determined by the appended patent application scope.

13:Maintenance Department

13a, 13b: flat part

13c, 13d: inclined part

13e: Right angle part

Claims (7)

A piezoelectric vibrating plate includes a vibrating part, an outer frame surrounding the outer periphery of the vibrating part, and a holding part connecting the vibrating part and the outer frame, wherein the holding parts are facing each other. A pair of main surface portions, that is, a first main surface portion and a second main surface portion are each provided with a flat portion, and one of the flat portions of the first main surface portion and the second main surface portion is located at the corresponding flat portion. The width of the holding portion in the width direction is greater than the width of the other flat portion in the width direction of the holding portion. A piezoelectric vibrating plate includes a vibrating part, an outer frame surrounding the outer periphery of the vibrating part, and a holding part connecting the vibrating part and the outer frame, wherein the holding parts are facing each other. A pair of main surface portions, that is, a first main surface portion and a second main surface portion are each provided with a flat portion, and one of the flat portions of the first main surface portion and the second main surface portion is located at the corresponding flat portion. One end in the width direction of the holding portion is closer to the one end in the width direction than the other flat portion. The piezoelectric vibration plate according to claim 1 or 2, wherein the other end of the flat portion of each of the first main surface portion and the second main surface portion in the width direction of the holding portion is in the holding portion. are arranged at approximately the same position in the width direction of the parts. The piezoelectric vibration plate according to claim 1 or 2, wherein: the piezoelectric vibration plate is an AT-cut crystal piece, and the first main surface part and the second main surface part are arranged parallel to the AT-cut XZ ' Plane, the first main surface is provided on the +Y direction side, and the second main surface is provided on the -Y direction side. The piezoelectric vibration plate according to claim 4, wherein: only one holding portion is provided, and the holding portion extends from the corners of the vibration portion on the +X direction side and the -Z ' direction side to -Z ' Extend sideways. A piezoelectric vibration device, including the piezoelectric vibration plate according to claim 1 or 2. The piezoelectric vibration device according to claim 6, further comprising: a first sealing member covering one main surface side of the vibration portion of the piezoelectric vibration plate; and the vibration member covering the piezoelectric vibration plate. The second sealing member on the other main surface side of the portion is bonded to the piezoelectric vibration plate through the first sealing member and the second sealing member is bonded to the piezoelectric vibration plate, and the piezoelectric vibration plate The vibrating portion of the plate is sealed.