Piezoelectric vibration plate, piezoelectric vibration device, and method for manufacturing piezoelectric vibration device

Abstract

The present invention includes: first and second excitation electrodes formed on two main surfaces of a piezoelectric substrate; and first and second mounting terminals respectively connected to the first and second excitation electrodes. The first and second mounting terminals have: a mounting metal film including a solder resist metal film formed on the piezoelectric substrate; and excitation metal films constituting the first and second excitation electrodes formed on the mounting metal film so as to be respectively connected to the first and second excitation electrodes.

Description

Technical Field

[0001] The present invention relates to a piezoelectric vibrating plate having mounting terminals, a piezoelectric vibrating device using the piezoelectric vibrating plate, and a method for manufacturing the piezoelectric vibrating device. Background Art

[0002] As a piezoelectric vibrating device, for example, as a piezoelectric oscillator, a surface-mount type crystal oscillator is widely used. Such a surface-mount type crystal oscillator is, for example, as described in Patent Document 1, in which electrodes led out from excitation electrodes on both surfaces of a crystal vibrating piece are fixed to holding electrodes in a box-shaped base made of ceramics and having an open upper surface by a conductive adhesive, thereby mounting the crystal vibrating piece on the base. At the opening of the base on which the crystal vibrating piece is mounted in this way, a lid body is joined for airtight sealing. In addition, mounting terminals for surface-mounting the crystal oscillator are formed on the outer bottom surface of the base.

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2005-184325

[0004] As described above, since most of the piezoelectric oscillators are packages formed by joining a metal or glass lid to a ceramic base, the packages become expensive and the piezoelectric oscillators become expensive.

[0005] In a surface-mount type piezoelectric oscillator, since its mounting terminals are mounted by joining with a joining material such as solder to a circuit board or the like, it is necessary to avoid conduction failure caused by so-called solder corrosion due to diffusion of the metal constituting the mounting terminals into the attached solder. Summary of the Invention

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a piezoelectric vibrating plate and a piezoelectric vibrating device that do not cause conduction failure and are inexpensive.

[0007] In the present invention, in order to achieve the above object, the following configuration is adopted.

[0008] (1) The piezoelectric vibrating plate of the present invention includes: a piezoelectric substrate having a substantially rectangular shape in plan view; first and second excitation electrodes formed on two main surfaces of the piezoelectric substrate; and first and second mounting terminals respectively connected to the first and second excitation electrodes at both ends in the direction of a set of opposite sides of the piezoelectric substrate along the substantially rectangular shape in plan view. The first and second mounting terminals have: a mounting metal film including an anti-solder metal film formed on the piezoelectric substrate; and excitation metal films constituting the first and second excitation electrodes formed on the mounting metal film so as to be respectively connected to the first and second excitation electrodes.

[0009] In the piezoelectric vibrating plate according to the present invention, since the first and second mounting terminals joined to a circuit board or the like by a joining material such as solder have a mounting metal film including an anti-solder metal film, the anti-solder metal film of the mounting metal film can suppress the diffusion of solder corrosion to prevent conduction failure. On the other hand, since the excitation metal films constituting the first and second excitation electrodes are formed on the mounting metal films of the first and second mounting terminals so as to be respectively connected to the first and second excitation electrodes, the first and second mounting terminals can be respectively connected to the first and second excitation electrodes.

[0010] In addition, since the piezoelectric vibrating plate has the first and second mounting terminals respectively connected to the first and second excitation electrodes, it is not necessary to accommodate and mount a piezoelectric vibrating piece in a box-shaped base having a mounting terminal and an open upper surface as in the prior art, and an expensive base is not required.

[0011] (2) In a preferred embodiment of the present invention, in the mounting metal film and the excitation metal film on the mounting metal film, by dividing a part of the mounting metal film and the excitation metal film, a dividing groove exposing the anti-solder metal film is formed in a manner crossing the direction along the set of opposite sides of the piezoelectric substrate.

[0012] The mounting terminals are provided at both ends in the direction of one set of opposite sides of the piezoelectric substrate that is substantially rectangular in plan view. According to this embodiment, a part of the mounting metal film and the excitation metal film of the mounting terminals at both ends are divided in a manner crossing the direction along the opposite sides by the dividing groove exposing the anti-solder metal film.

[0013] Therefore, in the piezoelectric substrate that is substantially rectangular in plan view, a part of the mounting metal film and the excitation metal film of the mounting terminals at each end are divided into an outer region and an inner region close to the opposite sides with the dividing groove as a boundary.

[0014] Thus, the diffusion of solder corrosion generated in the outer region of the mounting metal film and the excitation metal film of the mounting terminal to the inner region can be suppressed by the dividing groove exposing the anti-solder metal film.

[0015] (3) In an embodiment of the present invention, the anti-solder metal film includes at least one of Ni and Ni alloy.

[0016] According to this embodiment, the diffusion of solder corrosion can be suppressed by the anti-solder metal film including at least one of Ni and Ni alloy.

[0017] (4) The piezoelectric vibration device of the present invention includes: a piezoelectric vibration plate having first and second excitation electrodes formed on two main surfaces of a piezoelectric substrate that is substantially rectangular in plan view, and first and second mounting terminals connected to the first and second excitation electrodes respectively at both ends in the direction of one set of opposite sides of the piezoelectric substrate along the two sets of opposite sides that are substantially rectangular in plan view; and first and second sealing members that are joined to the two main surfaces of the piezoelectric vibration plate so as to cover the first and second excitation electrodes of the piezoelectric vibration plate respectively, and at least one of the first and second sealing members is a resin film. The first and second mounting terminals of the piezoelectric vibration plate have: a mounting metal film including an anti-solder metal film formed on the piezoelectric substrate; and excitation metal films that form the first and second excitation electrodes and are formed on the mounting metal film so as to be connected to the first and second excitation electrodes respectively.

[0018] In the piezoelectric vibration device according to the present invention, since the first and second mounting terminals joined to a circuit board or the like by a bonding material such as solder have a mounting metal film including an anti-solder metal film, the anti-solder metal film of the mounting metal film can suppress the spread of solder corrosion to prevent conduction failure. On the other hand, since the excitation metal films that form the first and second excitation electrodes are formed on the mounting metal films of the first and second mounting terminals so as to be connected to the first and second excitation electrodes respectively, the first and second mounting terminals can be connected to the first and second excitation electrodes respectively.

[0019] In addition, since the piezoelectric vibration plate has the first and second mounting terminals connected to the first and second excitation electrodes respectively, it is not necessary to accommodate and mount a piezoelectric vibration piece in a box-shaped base having a mounting terminal and an open upper surface as in the prior art, and an expensive base is not required.

[0020] Furthermore, since at least one of the first and second sealing members joined to the two main surfaces of the piezoelectric vibration plate is a resin film, the cost can be reduced compared with a structure sealed with a metal or glass cover.

[0021] (5) In a preferred embodiment of the present invention, the two sealing members, i.e., the first and second sealing members, are the resin films.

[0022] According to this embodiment, since the two sealing members are constructed of resin films, an expensive base and cover are not required, and the cost can be further reduced.

[0023] (6) In one embodiment of the present invention, in the mounting metal film and the excitation metal film on the mounting metal film, by dividing a part of the mounting metal film and the excitation metal film, a dividing groove exposing the solder resist metal film is formed in a manner crossing the direction along a set of opposite sides of the piezoelectric substrate.

[0024] The mounting terminals are provided at both ends in the direction of a set of opposite sides among two sets of opposite sides that are substantially rectangular in plan view of the piezoelectric substrate. According to this embodiment, a part of the mounting metal film and the excitation metal film of the mounting terminals at both ends are divided by the dividing groove in a manner crossing the direction along the opposite sides. Therefore, in the piezoelectric substrate that is substantially rectangular in plan view, a part of the mounting metal film and the excitation metal film of the mounting terminals at each end are divided into a region closer to the outside and a region closer to the inside in the direction along the opposite sides with the dividing groove as the boundary.

[0025] Thus, it is possible to suppress the spread of solder corrosion generated in the region closer to the outside of the mounting metal film and the excitation metal film of the mounting terminal to the region closer to the inside through the dividing groove exposing the solder resist metal film.

[0026] (7) In another embodiment of the present invention, the resin thin film is joined to the piezoelectric vibrating plate so as to cover the dividing groove.

[0027] According to this embodiment, since the resin thin film is joined so as to cover the dividing groove of the mounting terminal of the piezoelectric vibrating plate, it is possible to prevent solder for joining the mounting terminal to a circuit board or the like from entering the dividing groove of the mounting terminal, and it is possible to effectively suppress the spread of solder corrosion through the dividing groove.

[0028] (8) In one embodiment of the present invention, the piezoelectric vibrating plate has: a vibrating portion in which the first and second excitation electrodes are respectively formed on two main surfaces of the piezoelectric substrate; and an outer frame portion connected to the vibrating portion through a connecting portion, the outer frame portion surrounds the outer periphery of the vibrating portion that is thinner than the outer frame portion at intervals, and the peripheral end portion of the thin film is joined to the outer frame portion to seal the vibrating portion.

[0029] According to this embodiment, by joining the peripheral end portion of the thin film to the outer frame portion surrounding the outer periphery of the vibrating portion, it is possible to seal the vibrating portion that is thinner than the outer frame portion without contacting the thin film joined to the outer frame portion.

[0030] (9) In another embodiment of the present invention, a first sealing pattern is formed on one of the two main surfaces of the outer frame portion. The first sealing pattern connects the first excitation electrode and the first mounting terminal. The first sealing pattern surrounds the vibrating portion and is joined to the thin film. A second sealing pattern is formed on the other of the two main surfaces of the outer frame portion. The second sealing pattern connects the second excitation electrode and the second mounting terminal. The second sealing pattern surrounds the vibrating portion and is joined to the thin film.

[0031] According to this embodiment, through the first and second sealing patterns respectively formed on the two main surfaces of the outer frame portion, the first and second excitation electrodes can be electrically connected to the first and second mounting terminals respectively, and the thin film can be firmly joined to the first and second sealing patterns surrounding the vibrating portion to seal the vibrating portion.

[0032] (10) In yet another embodiment of the present invention, the first and second mounting terminals are respectively formed on the two main surfaces of the outer frame portion. The first mounting terminals on the two main surfaces are connected to each other, and the second mounting terminals on the two main surfaces are connected to each other.

[0033] According to this embodiment, since the mounting terminals on the two main surfaces are electrically connected to each other respectively, when the piezoelectric vibration device is mounted on a circuit board or the like, it can be mounted on either of the two main surfaces.

[0034] (11) In a preferred embodiment of the present invention, the solder-resistant metal film includes at least one of Ni and Ni alloys.

[0035] According to this embodiment, through the solder-resistant metal film including at least one of Ni and Ni alloys, the spread of solder corrosion can be suppressed.

[0036] (12) Method for manufacturing a piezoelectric vibration device of the present invention. To manufacture a piezoelectric vibration plate, a piezoelectric wafer is prepared in advance. The piezoelectric vibration plate has: first and second excitation electrodes formed on two main surfaces of a piezoelectric substrate that is substantially rectangular in plan view; and first and second mounting terminals respectively connected to the first and second excitation electrodes at both ends in the direction of one set of opposite sides among two sets of opposite sides of the piezoelectric substrate that is substantially rectangular in plan view. The method for manufacturing the piezoelectric vibration device includes: an outer shape forming process of forming the outer shapes of a plurality of piezoelectric substrates on the piezoelectric wafer; a mounting metal film forming process of patterning a mounting metal film including an anti-solder metal film on the plurality of piezoelectric substrates formed in the outer shape forming process, so as to form the mounting metal film in the regions that become the first and second mounting terminals; a metal film forming process of patterning an excitation metal film on the plurality of piezoelectric substrates and on the mounting metal film on which the mounting metal film is formed in the mounting metal film forming process, so as to form the excitation metal film in the regions that become the first and second mounting terminals and the regions that become the first and second excitation electrodes to construct a piezoelectric vibration plate; a bonding process of bonding a resin thin film to at least one of the two main surfaces of the plurality of piezoelectric vibration plates on which the excitation metal film is formed in the metal film forming process to seal at least one of the first and second excitation electrodes; and a singulation process of singulating each piezoelectric vibration plate to which the thin film is bonded in the bonding process. In the metal film forming process, the excitation metal film is formed on the mounting metal film in the regions that become the first and second mounting terminals in a manner that is respectively connected to the excitation metal film in the regions that become the first and second excitation electrodes.

[0037] According to the method for manufacturing a piezoelectric vibration device of the present invention, since in the mounting metal film forming process, the mounting metal film is formed in the regions that become the first and second mounting terminals on the piezoelectric substrate, and in the metal film forming process, the excitation metal film is formed in the regions that become the first and second mounting terminals and the regions that become the first and second excitation electrodes on the piezoelectric substrate and on the anti-solder metal film, and the excitation metal film is formed on the mounting metal film in a manner that is respectively connected to the excitation metal film in the regions that become the first and second excitation electrodes, therefore, through the anti-solder metal film of the mounting metal film of the first and second mounting terminals, the diffusion of solder corrosion can be suppressed to prevent conduction failure. On the other hand, through the formation of the excitation metal film, the first and second mounting terminals can be respectively connected to the first and second excitation electrodes.

[0038] In addition, since the piezoelectric vibration plate has the first and second mounting terminals respectively connected to the first and second excitation electrodes, it is not necessary to accommodate and mount a piezoelectric vibration piece in a box-shaped base having a mounting terminal and an open upper surface as in the prior art, and an expensive base is not required.

[0039] Furthermore, in the bonding process, a resin film is bonded to at least one of the two main surfaces of the plurality of piezoelectric vibrating plates for sealing. Therefore, compared with the structure sealed with a lid made of metal or glass, the cost can be reduced.

[0040] (13) For a preferred embodiment of the present invention, in the bonding process, resin films are respectively bonded to the two main surfaces of the plurality of piezoelectric vibrating plates on which the excitation metal films are formed in the metal film forming process to respectively seal the first and second excitation electrodes.

[0041] According to this embodiment, since resin films are respectively bonded to the two main surfaces of the piezoelectric vibrating plate for sealing, expensive bases and lids are not required, and the cost can be further reduced.

[0042] (14) For an embodiment of the present invention, in the metal film forming process, in the mounting metal film and the excitation metal film formed on the mounting metal film, a dividing groove exposing the solder resist metal film is formed by dividing a part of the mounting metal film and the excitation metal film in a direction crossing a set of opposite sides of the piezoelectric substrate.

[0043] The mounting terminals are provided at both ends in the direction of a set of opposite sides of the piezoelectric substrate that is substantially rectangular in plan view. According to this embodiment, a part of the mounting metal film and the excitation metal film of the mounting terminals at both ends are divided by the dividing groove exposing the solder resist metal film in a direction crossing the direction of the opposite sides. Therefore, in the piezoelectric substrate that is substantially rectangular in plan view, a part of the mounting metal film and the excitation metal film of the mounting terminals at each end are divided into a region close to the outside and a region close to the inside in the direction of the opposite sides with the dividing groove as the boundary.

[0044] Thereby, the diffusion of solder corrosion generated in the region close to the outside of the mounting metal film and the excitation metal film of the mounting terminal to the region close to the inside can be suppressed by the dividing groove exposing the solder resist metal film.

[0045] (15) For another embodiment of the present invention, in the bonding process, the resin film is bonded to the piezoelectric vibrating plate so as to cover the dividing groove.

[0046] According to this embodiment, since the resin film is bonded so as to cover the dividing groove of the mounting terminal of the piezoelectric vibrating plate, solder used for bonding the mounting terminal to a circuit board or the like can be prevented from entering the dividing groove of the mounting terminal, and the diffusion of solder corrosion can be effectively suppressed by the dividing groove.

[0047] According to the present invention, since the first and second mounting terminals joined to a circuit board or the like by a joining material such as solder have a mounting metal film including an anti-solder metal film, the anti-solder metal film of the mounting metal film can suppress the spread of solder corrosion to prevent conduction failure. On the other hand, since the excitation metal films constituting the first and second excitation electrodes are formed on the mounting metal films of the first and second mounting terminals so as to be respectively connected to the first and second excitation electrodes, the first and second mounting terminals can be respectively connected to the first and second excitation electrodes.

[0048] In addition, since the piezoelectric vibrating plate has the first and second mounting terminals respectively connected to the first and second excitation electrodes, it is not necessary to house and mount the piezoelectric vibrating piece in a box-shaped base having a mounting terminal and an opening on the upper surface as in the prior art, and an expensive base is not required.

[0049] In addition, since at least one of the first and second sealing members joined to the two main surfaces of the piezoelectric vibrating plate is a resin thin film, the cost can be reduced as compared with a structure sealed by a metal or glass cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 is a schematic perspective view of a crystal oscillator according to an embodiment of the present invention.

[0051] Figure 2 is Figure 1 a schematic top view of the crystal oscillator.

[0052] Figure 3 is a schematic cross-sectional view taken along line A-A of Figure 2 the crystal oscillator.

[0053] Figure 4 is Figure 1 a schematic bottom view of the crystal oscillator.

[0054] Figure 5 is an enlarged Figure 3 schematic cross-sectional view showing the metal film structure.

[0055] Figure 6 is Figure 5 a cross-sectional view obtained by enlarging and vertically inverting the rectangular portion A of the crystal oscillator.

[0056] Figure 7A is a schematic cross-sectional view showing Figure 1 the manufacturing process of the crystal oscillator.

[0057] Figure 7B is a schematic cross-sectional view showing Figure 1 the manufacturing process of the crystal oscillator.

[0058] Figure 7C is a schematic cross-sectional view showing the manufacturing process of a crystal oscillator Figure 1 .

[0059] Figure 7D is a schematic cross-sectional view showing the manufacturing process of a crystal oscillator Figure 1 .

[0060] Figure 7E is a schematic cross-sectional view showing the manufacturing process of a crystal oscillator Figure 1 .

[0061] Figure 7F is a schematic cross-sectional view showing the manufacturing process of a crystal oscillator Figure 1 .

[0062] Figure 7G is a schematic cross-sectional view showing the manufacturing process of a crystal oscillator Figure 1 .

[0063] Figure 7H is a schematic cross-sectional view showing the manufacturing process of a crystal oscillator Figure 1 .

[0064] Figure 8 is a schematic top view of a crystal vibration plate constituting another embodiment of the present invention.

[0065] Figure 9 is Figure 8 a schematic bottom view of the crystal vibration plate. Detailed Embodiment

[0066] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this embodiment, a crystal oscillator applied as a piezoelectric vibration device will be described.

[0067] Figure 1 is a schematic perspective view of a crystal oscillator according to an embodiment of the present invention, Figure 2 is its schematic top view, Figure 3 is a schematic cross-sectional view along the A-A line of Figure 2 , Figure 4 is its schematic bottom view. In addition, in Figure 3 and the following Figure 5 , Figure 6 , Figures 7A to 7H , for ease of explanation, the thicknesses of the resin film and the metal film are exaggeratedly shown.

[0068] The crystal oscillator 1 of this embodiment includes: an AT-cut crystal vibration plate 2 as a piezoelectric vibration plate; a first resin film 3 as a first sealing member, which covers and seals one of the front and back main surfaces of the crystal vibration plate 2; and a second resin film 4 as a second sealing member, which covers and seals the other main surface side of the crystal vibration plate 2.

[0069] The crystal oscillator 1 has a rectangular parallelepiped shape and is rectangular in plan view. The crystal oscillator 1 of this embodiment is, for example, 1.2 mm × 1.0 mm in plan view and 0.2 mm in thickness, achieving miniaturization and low profile.

[0070] In addition, the size of the crystal oscillator 1 is not limited to the above, and different sizes can also be applied.

[0071] Next, the crystal vibration plate 2 and each structure of the first and second resin films 3 and 4 that constitute the crystal oscillator 1 will be described.

[0072] The crystal vibration plate 2 of this embodiment is an AT-cut crystal plate obtained by rotating a crystal plate 35° 15′ around the X-axis, which is the crystal axis of the crystal, and the new axes after rotation are referred to as the Y′-axis and the Z′-axis. In the AT-cut crystal plate, its front and back main surfaces are the XZ′ planes.

[0073] In this XZ′ plane, the short side direction ( Figure 2 、 Figure 4 the up and down direction) of the crystal vibration plate 2, which is rectangular in plan view, is the X-axis direction, and the long side direction ( Figure 2 、 Figure 4 the left and right direction) of the crystal vibration plate 2 is the Z′-axis direction. The long side direction (Z′-axis direction) of the crystal vibration plate 2 is along one of the two sets of opposite sides of the crystal vibration plate 2, which is rectangular in plan view.

[0074] The crystal vibration plate 2 includes: a vibration portion 21 that is substantially rectangular in plan view, an outer frame portion 23 that surrounds the periphery of the vibration portion 21 with a through portion 22 interposed therebetween, and a connecting portion 24 that connects the vibration portion 21 and the outer frame portion 23. The vibration portion 21, the outer frame portion 23, and the connecting portion 24 are integrally formed. The vibration portion 21 and the connecting portion 24 are formed thinner than the outer frame portion 23. That is, the vibration portion 21 is thinner than the outer frame portion 23. In order to cover the thin vibration portion 21, an internal space is formed and sealed by joining the peripheral portions of the first and second resin films 3 and 4 to the outer frame portion 23.

[0075] In this embodiment, since the vibration portion 21, which is substantially rectangular in plan view, is connected to the outer frame portion 23 by a connecting portion 24 provided at one corner thereof, the stress acting on the vibration portion 21 can be reduced as compared with a structure in which the connection is made at two or more locations.

[0076] In addition, in this embodiment, the connecting portion 24 protrudes from one side in the X-axis direction among the inner circumferences of the outer frame portion 23 and is formed along the Z'-axis direction. The first and second mounting terminals 27 and 28 formed at both ends of the crystal vibrating plate 2 in the Z'-axis direction are directly joined to a circuit board or the like by solder or the like. Therefore, it can be considered that shrinkage stress acts in the long side direction (Z'-axis direction) of the crystal oscillator, and since this stress propagates to the vibrating portion, the oscillation frequency of the crystal oscillator is likely to change.

[0077] In contrast, in this embodiment, since the connecting portion 24 is formed in the direction along the shrinkage stress, the propagation of this shrinkage stress to the vibrating portion 21 can be suppressed. As a result, the change in the oscillation frequency when the crystal oscillator 1 is mounted on the circuit board can be suppressed.

[0078] A pair of first and second exciting electrodes 25 and 26 are respectively formed on the front and back main surfaces of the vibrating portion 21. On the outer frame portion 23 at both ends in the long side direction ( Figures 2 to 4 the left-right direction) of the crystal vibrating plate 2 having a rectangular shape in plan view, along the short side direction of the crystal vibrating plate 2 ( Figure 2 , Figure 4 the up-down direction), the above-mentioned first and second mounting terminals 27 and 28 respectively connected to the first and second exciting electrodes 25 and 26 are formed. Each of the mounting terminals 27 and 28 is a terminal for mounting the crystal oscillator 1 on a circuit board or the like.

[0079] As Figure 2 shown, on one of the two main surfaces, the first mounting terminal 27 is provided in connection with a rectangular ring-shaped first sealing pattern 201 to be described later. As Figure 4 shown, on the other main surface, the second mounting terminal 28 is provided in connection with a rectangular ring-shaped second sealing pattern 202 to be described later.

[0080] In this way, the first and second mounting terminals 27 and 28 are respectively formed at both ends of the crystal vibrating plate 2 in the long side direction (Z'-axis direction) with the vibrating portion 21 interposed therebetween.

[0081] The first mounting terminals 27 between the two main surfaces of the crystal vibrating plate 2 and the second mounting terminals 28 are respectively electrically connected. In this embodiment, the first mounting terminals 27 between the two main surfaces and the second mounting terminals 28 are respectively electrically connected by lead electrodes wound around the side surfaces on the opposite long side of the crystal vibrating plate 2, and are respectively electrically connected by lead electrodes wound around the side surfaces on the opposite short side of the crystal vibrating plate 2.

[0082] On the front side of the crystal vibrating plate 2, a first sealing pattern 201 of a first resin film 3 is joined to form a rectangular ring surrounding a substantially rectangular vibrating portion 21. The first sealing pattern 201 includes: a connecting portion 201a connected to the first mounting terminal 27; first extending portions 201b, 201b respectively extending along the long side direction of the crystal vibrating plate 2 from both end portions of the connecting portion 201a; and a second extending portion 201c extending along the short side direction of the crystal vibrating plate 2 and connecting the extending ends of the first extending portions 201b, 201b. The second extending portion 201c is connected to a first lead-out electrode 203 led out from the first exciting electrode 25. Therefore, the first mounting terminal 27 is electrically connected to the first exciting electrode 25 through the first sealing pattern 201 and the first lead-out electrode 203. An electrode-free region 205a where no electrode is formed is provided between the second extending portion 201c extending along the short side direction of the crystal vibrating plate 2 and the second mounting terminal 28 to achieve insulation between the first sealing pattern 201 and the second mounting terminal 28. The electrode-free region 205a constitutes an insulating groove 36 described later between the second extending portion 201c of the first sealing pattern 201 and the second mounting terminal 28.

[0083] As Figure 4 shown, on the back side of the crystal vibrating plate 2, a second sealing pattern 202 of a second resin film 4 is joined to form a rectangular ring surrounding a substantially rectangular vibrating portion 21. The second sealing pattern 202 includes: a connecting portion 202a connected to the second mounting terminal 28; first extending portions 202b, 202b respectively extending along the long side direction of the crystal vibrating plate 2 from both end portions of the connecting portion 202a; and a second extending portion 202c extending along the short side direction of the crystal vibrating plate 2 and connecting the extending ends of the first extending portions 202b, 202b. The connecting portion 202a is connected to a second lead-out electrode 204 led out from the second exciting electrode 26. Therefore, the second mounting terminal 28 is electrically connected to the second exciting electrode 26 through the second sealing pattern 202 and the second lead-out electrode 204. An electrode-free region 206a where no electrode is formed is provided between the second extending portion 202c extending along the short side direction of the crystal vibrating plate 2 and the first mounting terminal 27 to achieve insulation between the second sealing pattern 202 and the first mounting terminal 27. The electrode-free region 206a constitutes an insulating groove 37 described later between the second extending portion 202c of the second sealing pattern 202 and the first mounting terminal 27.

[0084] As Figure 2 shown, the widths of the first extending portions 201b, 201b of the first sealing pattern 201 respectively extending along the long side direction of the crystal vibrating plate 2 are narrower than the width of the outer frame portion 23 extending along the long side direction. In the width direction of the first extending portions 201b, 201b ( Figure 2On both sides in the up-down direction), there are non-electrode regions 205b, 205b; 207b, 207b where no electrodes are formed.

[0085] Among the non-electrode regions 205b, 205b; 207b, 207b on both sides of the first extension portions 201b, 201b, one end side of the outer non-electrode regions 205b, 205b extends to the first mounting terminal 27, and the other end side is connected to the non-electrode region 205a(36) between the second mounting terminal 28 and the second extension portion 201c. Thus, the connection portions 201a of the first sealing pattern 201, the first extension portions 201b, 201b, and the outer sides of the second extension portions 201c are surrounded by non-electrode regions having substantially equal widths. This non-electrode region extends from the outside of one end of the connection portion 201a extending along the short side direction of the crystal vibration plate 2 along one first extension portion 201b, and extends from the extended end of this one first extension portion 201b along the second extension portion 201c, and extends from the extended end of this second extension portion 201c along the other first extension portion 201b to the outside of the other end of the connection portion 201a.

[0086] A non-electrode region 207a is formed inside the connection portion 201a of the first sealing pattern 201 in the width direction, and both ends of this non-electrode region 207a are connected to the non-electrode regions 207b, 207b inside the first extension portions 201b, 201b. Inside the second extension portion 201c in the width direction, except for the first lead electrode 203 of the connection portion 24, a non-electrode region 207c is formed, and this non-electrode region 207c is connected to the non-electrode regions 207b, 207b inside the first extension portions 201b, 201b. Thus, inside the connection portion 201a of the first sealing pattern 201, the first extension portions 201b, 201b, and the second extension portion 201c in the width direction, except for the first lead electrode 203 of the connection portion 24, are surrounded by non-electrode regions 207a, 207b, 207c, 207b having substantially equal widths and in a rectangular ring shape when viewed from above.

[0087] As Figure 4 shown, the widths of the first extension portions 202b, 202b of the second sealing pattern 202 that respectively extend along the long side direction of the crystal vibration plate 2 are narrower than the width of the outer frame portion 23 that extends along the long side direction. On both sides in the width direction ( Figure 4 of the up-down direction) of the first extension portions 202b, 202b, there are non-electrode regions 206b, 206b; 208b, 208b where no electrodes are formed.

[0088] On both sides of the first extension portions 202b and 202b, there are electrodeless regions 206b and 206b; among 208b and 208b, one end side of the outer electrodeless regions 206b and 206b extends to the second mounting terminal 28, and the other end side is connected to the electrodeless region 206a(37) between the first mounting terminal 27 and the second extension portion 202c. Thus, the connection portions 202a of the second sealing pattern 202, the outer sides of the first extension portions 202b and 202b, and the second extension portion 202c are surrounded by electrodeless regions having substantially equal widths. The electrodeless region extends from the outside of one end of the connection portion 202a extending along the short side direction of the crystal vibration plate 2 along one first extension portion 202b, and extends from the extended end of the one first extension portion 202b along the second extension portion 202c, and extends from the extended end of the second extension portion 202c along the other first extension portion 202b to the outside of the other end of the connection portion 202a.

[0089] Inside the width direction of the connection portion 202a of the second sealing pattern 202, except for the second lead electrode 204 of the connection portion 24, there is an electrodeless region 208a formed, and both ends of the electrodeless region 208a are connected to the electrodeless regions 208b and 208b inside the first extension portions 202b and 202b. An electrodeless region 208c is formed inside the width direction of the second extension portion 202c, and the electrodeless region 208c is connected to the electrodeless regions 208b and 208b inside the first extension portions 202b and 202b. Thus, inside the width direction of the connection portion 202a of the second sealing pattern 202, the first extension portions 202b and 202b, and the second extension portion 202c, except for the second lead electrode 204 of the connection portion 24, are surrounded by electrodeless regions 208a, 208b, 208c, and 208b having substantially equal widths and in a rectangular ring shape when viewed from above.

[0090] As described above, the first extension portions 201b, 201b; 202b, 202b of the first and second sealing patterns 201, 202 are narrower than the width of the outer frame portion 23. Electrode-free regions 205b, 207b; 206b, 208b are provided on both sides in the width direction of the first extension portions 201b, 201b; 202b, 202b, and electrode-free regions 207a, 207c; 208a, 208c are provided on the inner sides in the width direction of the connection portions 201a, 202a and the second extension portions 201c, 202c. The electrode-free regions 205b, 207a, 207b, 207c; 206b, 208a, 208b, 208c are formed in the following manner: that is, the first and second sealing patterns 201, 202 that wrap around the side surface of the outer frame portion 23 during sputtering are patterned by photolithography technology, and the first and second sealing patterns 201, 202 are removed by metal etching. Thus, it is possible to prevent a short circuit caused by the first and second sealing patterns 201, 202 wrapping around the side surface of the outer frame portion 23.

[0091] As described above, since the first mounting terminals 27 between the two main surfaces and the second mounting terminals 28 between the two main surfaces are electrically connected respectively, when the crystal oscillator 1 is mounted on a circuit board or the like, it can be mounted on either of the front and back main surfaces.

[0092] The first and second resin films 3, 4 that are respectively joined to the front and back main surfaces of the crystal vibration plate 2 and respectively seal the vibration portion 21 of the crystal vibration plate 2 are rectangular films. The sizes of the rectangular first and second resin films 3, 4 are such that they cover the rectangular region of the crystal vibration plate 2 except for the first and second mounting terminals 27, 28 at both ends in the long side direction, and the rectangular first and second resin films 3, 4 are joined to the rectangular region.

[0093] In this embodiment, the first and second resin films 3, 4 are heat-resistant resin films, for example, films made of polyimide resin, and have a heat resistance of about 300°C. The polyimide resin-made first and second resin films 3, 4 are transparent, but may become opaque depending on the heat press bonding conditions described later. In addition, the first and second resin films 3, 4 may also be transparent, opaque, or semi-transparent.

[0094] The first and second resin films 3, 4 are not limited to polyimide resin, and resins classified as super engineering plastics, such as polyamide resin or polyether ether ketone resin, etc., can also be used.

[0095] On the entire front and back surfaces of the first and second resin films 3 and 4, a thermoplastic adhesive layer is formed. The rectangular peripheral ends of the first and second resin films 3 and 4 are respectively heat-pressed and bonded to the outer frame portions 23 of the front and back main surfaces of the crystal vibrator plate 2 by hot pressing, for example, to seal the vibration portion 21.

[0096] Thus, since the first and second resin films 3 and 4 are heat-resistant resin films, they can withstand the high temperature of the solder reflow process when the crystal oscillator 1 is soldered and mounted on a circuit board or the like, and the first and second resin films 3 and 4 will not be deformed or the like.

[0097] In this embodiment, when the crystal oscillator 1 is soldered and mounted on a circuit board or the like, Au of the laminated metal film constituting the first and second mounting terminals 27 and 28 diffuses into the solder attached to the first and second mounting terminals 27 and 28, resulting in so-called solder corrosion, and thus conduction failure occurs. To prevent this phenomenon, it is configured as follows.

[0098] Figure 5 It is a schematic cross-sectional view after magnification to show the film structures of the first and second excitation electrodes 25 and 26, the first and second mounting terminals 27 and 28, etc. Figure 3 It is a schematic cross-sectional view after magnification. Figure 6 It is a magnified view of Figure 5 the rectangular portion A in Figure 5 It is a view obtained by inverting the upper and lower sides of

[0099] Each of the mounting terminals 27 and 28 includes a mounting metal film 13 formed on the crystal substrate constituting the crystal vibrator plate 2 and an excitation metal film 14 formed on the mounting metal film 13.

[0100] The mounting metal film 13 of this embodiment has a Ti film 30 as a base film, a Ni·Ti alloy film 31 as an anti-solder metal film, and an Au film 32 for improving solder wetting property. The anti-solder metal film is not limited to the Ni·Ti alloy film 31, and other metal films such as Ni films can also be used.

[0101] The excitation metal film 14 on the mounting metal film 13 includes a Ti film 33, an Au film 34, and a Ti film 35. The Ti films 33 and 35 of the excitation metal film 14 can also be other metal films such as Cr films.

[0102] Since the uppermost layer of the excitation metal film 14 on the mounting metal film 13 of the first and second mounting terminals 27 and 28 is the Ti film 35, the bonding strength with the first and second resin films 3 and 4 is improved compared with the case where the Au film 34 is the uppermost layer.

[0103] The excitation metal film 14 has the same film structure as the first and second excitation electrodes 25 and 26, and is formed by connecting the excitation metal films 14 on the mounting metal films 13 of the first and second mounting terminals 27 and 28 to the excitation metal films 14 constituting the first and second excitation electrodes respectively.

[0104] Therefore, the first lead electrode 203 and the first sealing pattern 201 that electrically connect the first mounting terminal 27 to the first excitation electrode 25 are also constituted by the excitation metal film 14. Similarly, the second lead electrode 204 and the second sealing pattern 202 that electrically connect the second mounting terminal 28 to the second excitation electrode 26 are also constituted by the excitation metal film 14.

[0105] On the front side of the crystal vibrating plate 2, which is one of the two main surfaces, an insulating groove 36 that constitutes the non-electrode region 205a for insulating the first sealing pattern 201 from the second mounting terminal 28 is formed. On the back side of the crystal vibrating plate 2, which is the other main surface, an insulating groove 37 that constitutes the non-electrode region 206a for insulating the second sealing pattern 202 from the first mounting terminal 27 is formed.

[0106] A dividing groove 38 is formed on the first mounting terminal 27 at a position directly opposite to the insulating groove 37 (206a) on the back side. The dividing groove 38 divides the Au film 32, which is a part of the mounting metal film 13 of the first mounting terminal 27, and the excitation metal film 14 on the mounting metal film 13 into inner and outer parts along the long side direction of the crystal vibrating plate 2 ( Figure 5 the left and right direction), exposing the Ni·Ti alloy film 31, which is the solder-resistant metal film. Similarly, a dividing groove 39 is formed on the second mounting terminal 28 at a position directly opposite to the insulating groove 36 (205a) on the front side. The dividing groove 39 divides the Au film 32, which is a part of the mounting metal film 13 of the first mounting terminal 28, and the excitation metal film 14 on the mounting metal film 13 into inner and outer parts along the long side direction of the crystal vibrating plate 2 ( Figure 5 、 Figure 6 the left and right direction), exposing the Ni·Ti alloy film 31, which is the solder-resistant metal film.

[0107] As Figure 2 、 Figure 4 shown, the dividing grooves 38 and 39 are formed in a manner that crosses the long side direction of the crystal vibrating plate 2, and in this example, they are formed perpendicular to the long side direction.

[0108] As Figure 5 shown, the dividing groove 38 divides the Au film 32 and the excitation metal film 14 of the mounting metal film 13 of the first mounting terminal 27 into a region closer to the outside, that is, a region closer to one edge in the long side direction ( Figure 5the region near the left side) and the region near the inner side, i.e., the region near the vibrating portion 21 ( Figure 5 the region near the right side). Similarly, the dividing groove 39 divides the Au film 32 of the mounting metal film 13 and the exciting metal film 14 of the second mounting terminal 28 into a region near the outer side, i.e., the region near the other edge in the long side direction ( Figure 5 the region near the right side) and the region near the inner side, i.e., the region near the vibrating portion 21 ( Figure 5 the region near the left side). Therefore, the Au film 32 of the mounting metal film 13 and the exciting metal film 14 of the first and second mounting terminals 27 and 28 are divided into a region near the outer side and a region near the inner side by the dividing grooves 38 and 39 where the Ni·Ti alloy film 31 serving as an anti-solder metal film is exposed.

[0109] Thus, even if solder corrosion occurs in the Au film 32 of the mounting metal film 13 or the Au film 34 of the exciting metal film 14 in the region near the outer side of the first and second mounting terminals 27 and 28, the solder corrosion can be suppressed from spreading to the inner region closer to the vibrating portion 21 side than the dividing grooves 38 and 39 by the dividing grooves 38 and 39 where the Ni·Ti alloy film 31 serving as an anti-solder metal film is exposed.

[0110] In addition, since the first and second mounting terminals 27 and 28 are completely separated from the inner metal film by the insulating grooves 36 (205a) and 37 (206a), even if solder corrosion occurs in the Au film 32 of the mounting metal film 13 or the Au film 34 of the exciting metal film 14 of the first and second mounting terminals 27 and 28, the solder corrosion can be prevented from spreading to the inner side on the vibrating portion 21 side.

[0111] Furthermore, since the first and second resin films 3 and 4 are joined to the front and back main surfaces of the crystal vibrating plate 2 in such a way as to respectively cover the insulating grooves 36 (205a), 37 (206a) and the dividing grooves 38 and 39 located at corresponding positions on the front and back, solder does not penetrate into the inside of the insulating grooves 36 (205a), 37 (206a) and the dividing grooves 38 and 39. Thus, solder corrosion in the insulating grooves 36 (205a), 37 (206a) and the dividing grooves 38 and 39 can be prevented.

[0112] Next, a method for manufacturing the crystal oscillator 1 of this embodiment will be described.

[0113] Figures 7A to 7H is a schematic cross-sectional view showing the process of manufacturing the crystal oscillator 1, showing a part in the wafer state.

[0114] First, prepare Figure 7AThe crystal wafer (AT-cut crystal plate) 5 before processing as shown. For this crystal wafer 5, using photolithography technology and etching technology, for example, wet etching is performed, as Figure 7B shown, the outer shapes such as a plurality of crystal substrate portions 2a and a frame portion (not shown) supporting them are formed, and further, the outer shapes such as an outer frame portion 23a and a vibrating portion 21a thinner than the outer frame portion 23a are formed in the crystal substrate portion 2a, that is, the outer shape forming process is performed.

[0115] Next, as Figure 7C shown, by sputtering technology or evaporation technology, and photolithography technology, an installation metal film 13 including a Ni·Ti alloy film 30 as an anti-solder metal film is formed on the entire surface of the crystal substrate portion 2a.

[0116] Furthermore, as Figure 7D shown, an installation metal film forming process for patterning the installation metal film 13 is performed, and the metal films of unnecessary portions such as the vibrating portion 21a and the insulating grooves 36a, 37a other than the first and second installation terminals 27a, 28a are removed.

[0117] Next, as Figure 7E shown, by sputtering technology or evaporation technology, and photolithography technology, an excitation metal film 14 is formed on the entire surface of the crystal substrate portion 2a.

[0118] Furthermore, as Figure 7F shown, a metal film forming process is performed, that is, patterning of the excitation metal film 14 to remove unnecessary portions in the excitation metal film 14, and insulating grooves 36, 37 and dividing grooves 38, 39 are formed to construct a crystal vibrating plate.

[0119] In this embodiment, furthermore, as Figure 7G shown, a bonding process is performed, that is, the resin films 3a, 4a are heated and pressed in such a way that the front and back main surfaces of the crystal substrate portion 2a are respectively covered with the continuous resin films 3a, 4a to seal each vibrating portion 21a of each crystal substrate portion 2a.

[0120] The sealing of each vibrating portion 21a by the resin films 3a, 4a is performed in an inert gas atmosphere such as nitrogen.

[0121] Next, as Figure 7H shown, a singulation process is performed, that is, the continuous resin films 3a, 4a are cut corresponding to each crystal vibrating plate 2 so that a part of the first and second installation terminals 27, 28 is exposed, and unnecessary portions are removed, and each crystal vibrating plate 2 is separated and made single-chip.

[0122] Accordingly, a plurality of Figure 1 、 Figure 5 such as the crystal oscillators 1 shown are obtained.

[0123] As described above, according to the present embodiment, since the first and second mounting terminals 27 and 28 joined to a circuit board or the like by soldering have the mounting metal film 13 including the Ni·Ti alloy film 31 as the solder-resistant metal film, even if so-called solder corrosion occurs due to the diffusion of the Au film 32 of the mounting metal film 13 or the Au film 34 of the excitation metal film 14 on the mounting metal film 13 into the solder, the diffusion of the solder corrosion can be suppressed by the Ni·Ti alloy film 31, and conduction failure can be prevented from occurring.

[0124] In addition, on the mounting metal film 13 of the first and second mounting terminals 27 and 28 and the excitation metal film 14 on the mounting metal film 13, by dividing the Au film 32 of the mounting metal film 13 and the excitation metal film 14, dividing grooves 38 and 39 exposing the Ni·Ti alloy film 31 as the solder-resistant metal film are formed in a manner perpendicular to the long side direction of the crystal vibration plate 2. Therefore, the Au film 32 of the mounting metal film 13 and the excitation metal film 14 of each mounting terminal 27 and 28 are divided into an outer region near each end edge in the long side direction and an inner region near the vibration portion 21.

[0125] Thus, even if solder corrosion occurs in the Au film 32 of the mounting metal film 13 or the Au film 34 of the excitation metal film 14 in the outer region of the first and second mounting terminals 27 and 28, the diffusion of the solder corrosion into the inner region on the side closer to the vibration portion 21 than the dividing grooves 38 and 39 can be suppressed by the dividing grooves 38 and 39 exposing the Ni·Ti alloy film 31 as the solder-resistant metal film.

[0126] Furthermore, since the first and second resin films 3 and 4 are respectively joined to the front and back main surfaces of the crystal vibration plate 2 to cover the dividing grooves 38 and 39, solder can be prevented from entering the inside of the dividing grooves 38 and 39, and thus the diffusion of solder corrosion in the dividing grooves 38 and 39 can be prevented.

[0127] In addition, since the crystal vibration plate 2 has the first and second mounting terminals 27 and 28 respectively connected to the first and second excitation electrodes 25 and 26, there is no need to house and mount the piezoelectric vibration piece in a box-shaped base made of an insulating material such as ceramics having a mounting terminal and an upper surface opening as in the past, and an expensive base is not required.

[0128] Furthermore, since the first and second resin films 3 and 4 are bonded to the front and back main surfaces of the crystal vibration plate 2 to seal the first and second excitation electrodes 25 and 26, there is no need to accommodate and airtight seal the piezoelectric vibration piece in a box-shaped base with an opening on the upper surface as in the prior art, which can further reduce costs and achieve a thinner (lower height) compared with the existing examples.

[0129] In the crystal oscillator 1 of the present embodiment, since the vibration part 21 is sealed by the first and second resin films 3 and 4, the airtightness is poor compared with the existing examples in which a metal or glass cover is bonded to the base for airtight sealing, and the time-dependent change of the resonance frequency of the crystal oscillator 1 is likely to occur.

[0130] However, for example, in applications such as low-power Bluetooth (BLE, Bluetooth (registered trademark) Low Energy) for short-range wireless communication, since the standards such as frequency deviation are relatively loose, in related applications, an inexpensive crystal oscillator 1 sealed with a resin film can be used.

[0131] In the above embodiment, the dividing grooves 38 and 39 are formed so as to cross the long side direction of the crystal vibration plate 2 at a right angle, but are not limited to a right angle, and may be formed so as to obliquely cross the long side direction of the crystal vibration plate 2. In addition, the dividing grooves 38 and 39 are not limited to a linear shape and may be a curved shape.

[0132] As another embodiment of the present invention, the dividing grooves 38 and 39 may be omitted.

[0133] In the above embodiment, the connecting portion 24 is provided at one corner of the vibration portion 21 that is substantially rectangular in plan view, but the formation position and the number of formations of the connecting portion 24 are not limited thereto. Furthermore, the width of the connecting portion 24 may not be constant.

[0134] In addition, instead of having a through portion, it may be applied to an inverted boss-type crystal vibration plate in which the vibration portion is thin and its peripheral portion is thick.

[0135] In the above embodiment, the first and second resin films 3 and 4 are bonded to the two main surfaces of the crystal vibration plate 2 to seal the vibration portion 21, but a resin film may be bonded only to one main surface of the crystal vibration plate 2, and a conventional cover may be bonded to the other main surface to seal the vibration portion 21. In this case, the uppermost Ti film 35 on the main surface on the side where the cover is to be bonded may also be omitted.

[0136] In the above-described embodiment, the first mounting terminals 27 between the two main surfaces and the second mounting terminals 28 are electrically connected by the lead electrodes on the side surface or end surface of the crystal vibrating plate 2, but they may also be electrically connected by through electrodes penetrating the two main surfaces, or may be electrically connected by through electrodes while being electrically connected by the lead electrodes on the side surface or end surface.

[0137] In the above-described embodiment, as Figure 2 shown, on one of the two main surfaces of the crystal vibrating plate 2, the first sealing pattern 201 is formed in a rectangular ring shape so as to surround the substantially rectangular vibrating portion 21, and as Figure 4 shown, on the other of the two main surfaces of the crystal vibrating plate 2, the second sealing pattern 202 is formed in a rectangular ring shape so as to surround the substantially rectangular vibrating portion 21, but the rectangular ring-shaped first and second sealing patterns 201 and 202 may be omitted.

[0138] Figure 8 And Figure 9 are a schematic top view and a schematic bottom view of the crystal vibrating plate 21 in which the first and second sealing patterns 201 and 202 are omitted.

[0139] In this crystal vibrating plate 21, as Figure 8 shown, the first mounting terminal 27 is electrically connected to the first exciting electrode 25 through the lead electrode 209 and the first lead-out electrode 203.

[0140] As Figure 9 shown, the second lead-out electrode 204 of the second mounting terminal 28 is extended and electrically connected to the second exciting electrode 26.

[0141] In the connection portion between the lead electrode 209 and the first mounting terminal 27 and the connection portion between the extended second lead-out electrode 204 and the second mounting terminal 28, split grooves 381 and 391 are respectively formed.

[0142] Other structures are the same as those in the above-described embodiment.

[0143] In addition, in the crystal vibrating plate 21 in which the rectangular ring-shaped first and second sealing patterns 201 and 202 are omitted, a photosensitive resin film may be used as the resin film.

[0144] For example, as described above Figure 7G shown, a crystal wafer in which a plurality of crystal vibrating plates 21 are arranged and supported in a matrix may also be prepared, photosensitive resin films are respectively pasted on the two main surfaces of the crystal wafer, the photosensitive resin films are exposed and developed, the first and second exciting electrodes of the crystal vibrating plates 21 are respectively covered, and patterning and hardening of removing unnecessary portions are performed, and then the crystal wafer is singulated into each crystal vibrating plate.

[0145] The crystal vibration plate only needs to be approximately rectangular when viewed from above, and is not limited to the above-mentioned rectangular shape when viewed from above. For example, it can also be a shape with chamfered corners of the crystal vibration plate, or a shape with a castle-shaped structure, etc. The castle-shaped structure is formed by cutting the peripheral portion of the crystal vibration plate in the thickness direction and covering the cut portion with an electrode.

[0146] The present invention is not limited to piezoelectric vibrators such as crystal oscillators, and can also be applied to other piezoelectric vibration devices such as piezoelectric oscillators.

[0147] Description of reference numerals

[0148] 1 Crystal oscillator

[0149] 2 Crystal vibration plate

[0150] 3 First resin film

[0151] 4 Second resin film

[0152] 5 Crystal wafer

[0153] 13 Mounting metal film

[0154] 14 Excitation metal film

[0155] 21 Vibration part

[0156] 23 Outer frame part

[0157] 24 Connection part

[0158] 25 First excitation electrode

[0159] 26 Second excitation electrode

[0160] 27 First mounting terminal

[0161] 28 Second mounting terminal

[0162] 30, 33, 35 Ti film

[0163] 31 Ni·Ti alloy film (anti-solder metal film)

[0164] 32, 34 Au film

[0165] 38, 39 Partition groove

[0166] 201 First sealing pattern

[0167] 202 Second sealing pattern

Claims

1. A piezoelectric vibrating plate, comprising: a piezoelectric substrate having a rectangular shape in plan view; first and second exciting electrodes formed on two main surfaces of the piezoelectric substrate; and first and second mounting terminals respectively connected to the first and second exciting electrodes at both ends in the direction of one set of opposite sides of the piezoelectric substrate along the two sets of opposite sides having a rectangular shape in plan view, The first and second mounting terminals each have: a mounting metal film including a solder-resistant metal film formed on the piezoelectric substrate; and exciting metal films constituting the first and second exciting electrodes formed on the mounting metal film so as to be respectively connected to the first and second exciting electrodes, In the mounting metal film and the exciting metal films on the mounting metal film, a dividing groove is formed in a manner crossing the direction of the one set of opposite sides of the piezoelectric substrate, and the dividing groove divides a part of the mounting metal film and the exciting metal films and exposes the solder-resistant metal film.

2. The piezoelectric vibration plate according to claim 1, wherein, The solder-resistant metal film includes at least one of Ni and Ni alloys.

3. A piezoelectric vibrating device, comprising: A piezoelectric vibrating plate having first and second exciting electrodes formed on two main surfaces of a piezoelectric substrate having a rectangular shape in plan view, and first and second mounting terminals respectively connected to the first and second exciting electrodes at both ends in the direction of one set of opposite sides of the piezoelectric substrate along the two sets of opposite sides having a rectangular shape in plan view; and First and second sealing members that are respectively joined to the two main surfaces of the piezoelectric vibrating plate so as to cover the first and second exciting electrodes of the piezoelectric vibrating plate, At least one of the first and second sealing members is a resin thin film, The first and second mounting terminals of the piezoelectric vibrating plate each have: a mounting metal film including a solder-resistant metal film formed on the piezoelectric substrate; and exciting metal films constituting the first and second exciting electrodes formed on the mounting metal film so as to be respectively connected to the first and second exciting electrodes, In the mounting metal film and the exciting metal films on the mounting metal film, a dividing groove is formed in a manner crossing the direction of the one set of opposite sides of the piezoelectric substrate, and the dividing groove divides a part of the mounting metal film and the exciting metal films and exposes the solder-resistant metal film.

4. The piezoelectric vibration device according to claim 3, wherein, Both of the first and second sealing members are the resin thin films.

5. The piezoelectric vibration device according to claim 3, wherein, The resin thin film is joined to the piezoelectric vibrating plate so as to cover the dividing groove.

6. The piezoelectric vibration device according to claim 4, wherein, The resin thin film is joined to the piezoelectric vibrating plate so as to cover the dividing groove.

7. The piezoelectric vibration device according to claim 3, wherein, The piezoelectric vibrating plate has: a vibrating portion in which the first and second exciting electrodes are respectively formed on two main surfaces of the piezoelectric substrate; and an outer frame portion connected to the vibrating portion through a connecting portion, and the outer frame portion surrounds the outer periphery of the vibrating portion that is thinner than the outer frame portion with a space therebetween, The peripheral end portion of the thin film is joined to the outer frame portion to seal the vibrating portion.

8. The piezoelectric vibration device according to claim 4, wherein, The piezoelectric vibrating plate has: a vibrating portion in which the first and second exciting electrodes are respectively formed on two main surfaces of the piezoelectric substrate; and a frame portion connected to the vibrating portion through a connecting portion, the frame portion surrounding the outer periphery of the vibrating portion, which is thinner than the frame portion, at an interval. The peripheral end portion of the thin film is joined to the frame portion to seal the vibrating portion.

9. The piezoelectric vibration device according to claim 5, wherein, The piezoelectric vibrating plate has: a vibrating portion in which the first and second exciting electrodes are respectively formed on two main surfaces of the piezoelectric substrate; and a frame portion connected to the vibrating portion through a connecting portion, the frame portion surrounding the outer periphery of the vibrating portion, which is thinner than the frame portion, at an interval. The peripheral end portion of the thin film is joined to the frame portion to seal the vibrating portion.

10. The piezoelectric vibration device according to claim 6, wherein, The piezoelectric vibrating plate has: a vibrating portion in which the first and second exciting electrodes are respectively formed on two main surfaces of the piezoelectric substrate; and a frame portion connected to the vibrating portion through a connecting portion, the frame portion surrounding the outer periphery of the vibrating portion, which is thinner than the frame portion, at an interval. The peripheral end portion of the thin film is joined to the frame portion to seal the vibrating portion.

11. The piezoelectric vibration device according to any one of claims 7 to 10, wherein, A first sealing pattern is formed on one of the two main surfaces of the frame portion, the first sealing pattern connecting the first exciting electrode and the first mounting terminal, the first sealing pattern surrounding the vibrating portion and being joined to the thin film, and a second sealing pattern is formed on the other of the two main surfaces of the frame portion, the second sealing pattern connecting the second exciting electrode and the second mounting terminal, the second sealing pattern surrounding the vibrating portion and being joined to the thin film.

12. The piezoelectric vibration device according to any one of claims 7 to 10, wherein, The first and second mounting terminals are respectively formed on two main surfaces of the frame portion, the first mounting terminals on the two main surfaces being connected to each other, and the second mounting terminals on the two main surfaces being connected to each other.

13. The piezoelectric vibration device according to any one of claims 3 to 10, wherein, The solder resistive metal film includes at least one of Ni and Ni alloys.

14. A method of manufacturing a piezoelectric vibration device In order to manufacture a piezoelectric vibrating plate, a piezoelectric wafer is prepared in advance, the piezoelectric vibrating plate having: first and second exciting electrodes formed on two main surfaces of a piezoelectric substrate having a rectangular shape in plan view; and first and second mounting terminals respectively connected to the first and second exciting electrodes at both end portions in the direction of a set of opposite sides of the piezoelectric substrate among two sets of opposite sides having a rectangular shape in plan view. The method of manufacturing the piezoelectric vibration device includes: An outer shape forming step of forming the outer shapes of a plurality of piezoelectric substrates on the piezoelectric wafer; A mounting metal film forming step of patterning a mounting metal film including a solder resistive metal film on the plurality of piezoelectric substrates formed in the outer shape forming step, so as to form the mounting metal film in the regions to be the first and second mounting terminals; A metal film forming step of patterning an exciting metal film on the plurality of piezoelectric substrates on which the mounting metal film has been formed in the mounting metal film forming step and on the mounting metal film, so as to form the exciting metal film in the regions to be the first and second mounting terminals and the regions to be the first and second exciting electrodes to construct a piezoelectric vibrating plate. Bonding step: A resin film is bonded to at least one of the two main surfaces of a plurality of the piezoelectric vibrating plates on which the excitation metal film is formed in the metal film forming step to seal at least one of the first and second excitation electrodes; and Slicing step: Each piezoelectric vibrating plate bonded with the film in the bonding step is sliced; In the metal film forming step, the excitation metal film is formed on the mounting metal film in the region that becomes the first and second mounting terminals in such a manner that it is respectively connected to the excitation metal film in the region that becomes the first and second excitation electrodes; In the metal film forming step, in the mounting metal film and the excitation metal film formed on the mounting metal film, a dividing groove is formed in a direction crossing the direction along the pair of opposite sides of the piezoelectric substrate. The dividing groove divides a part of the mounting metal film and the excitation metal film and exposes the solder resist metal film.

15. The manufacturing method of the piezoelectric vibration device according to claim 14, wherein, In the bonding step, resin films are bonded to the two main surfaces of a plurality of the piezoelectric vibrating plates on which the excitation metal film is formed in the metal film forming step to respectively seal the first and second excitation electrodes.

16. The manufacturing method of the piezoelectric vibration device according to claim 14, wherein, In the bonding step, the resin film is bonded to the piezoelectric vibrating plate so as to cover the dividing groove.

Images