JP5632627B2 - Quartz crystal - Google Patents

Description

  The present invention relates to a crystal resonator element constituting a crystal resonator.

Various materials are known as materials that can be expected to have a piezoelectric effect. Conventionally, quartz that can obtain a stable and accurate frequency is preferably used. A crystal resonator is known as one of devices using this crystal.
This crystal unit is mainly composed of a crystal resonator element in which an electrode film is formed on a crystal diaphragm formed in a predetermined shape, and a holder for packaging the crystal resonator element in an airtight state. Built in various electronic devices.

  The quartz crystal resonator element is a surface-mounted component that is mounted in a cage, and is mounted via a mounting member. At this time, the crystal vibrating piece is not only mechanically held by the mounting member, but also its own electrode film and the inner electrode on the cage side are electrically connected via the mounting member. . Therefore, as the mounting member, a conductive adhesive, a gold bump or the like is preferably used.

In addition, when mounting a crystal resonator element, it is important to ensure high mounting strength and maintain quality, but at the same time, it is important to mount without affecting the excited vibration as much as possible. It is said that. That is, it is important to mount without deteriorating the vibration characteristics.
For this reason, it is necessary to determine the position of the mounting member with respect to the quartz crystal resonator element based on a viewpoint in consideration of strength and vibration characteristics.

Incidentally, quartz has various vibration modes depending on its crystallinity and piezoelectricity, and parameters for determining the frequency differ depending on the vibration mode. Among these, an AT vibrating piece that performs thickness-slip vibration is known as a quartz crystal vibrating piece whose thickness is a parameter.
This AT vibrating piece is formed into a predetermined thickness and rectangular shape after AT is cut (cut so that the main surfaces of the front and back surfaces are at an angle of about 35 degrees 15 minutes from the Z axis in the counterclockwise direction around the X axis). It is a vibration piece composed of an externally formed AT diaphragm (quartz crystal diaphragm) and an electrode film formed on the main surface of the AT diaphragm. When a voltage is applied to the electrode film, the AT diaphragm Oscillates in thickness and thickness.

  In such an AT resonator element, if the thickness is gradually reduced from the center toward the end, the attenuation of vibration displacement at the end increases, and the effect of confining vibration energy in the center can be expected. It has been known. This effect leads to improvement of frequency characteristics such as CI value and Q value. Therefore, it is preferable to make such a shape when manufacturing the AT vibrating piece. Specifically, a convex shape in which the main surface of the AT diaphragm is a convex curved surface, a bevel shape in which a central portion and an end portion of the main surface are connected by an inclined surface, and the like.

Among these, when mounting a quartz vibrating piece subjected to beveling, a piezoelectric vibrator is known in consideration of the mounting strength and vibration characteristics described above (see Patent Document 1).
In this piezoelectric vibrator, bumps are employed as mounting members, and a plurality of positions are arranged along contour lines along the beveling arc. Moreover, the size of the bump is changed in accordance with the curvature of the piezoelectric vibrating piece to absorb the difference in height when it is held.
As described above, since a plurality of bumps are arranged in a contour line and the difference in height when the bumps are held is absorbed, high mounting strength is ensured. In addition, since the bump is positioned at the beveled portion that hardly affects the vibration characteristics, the vibration is not easily inhibited by the bump, and the vibration characteristics are not easily affected.

Japanese Patent No. 3432951

By the way, this type of piezoelectric vibrator is required to be further miniaturized with the recent trend toward downsizing and downsizing of electronic devices. This also applies to a crystal resonator that is also one of piezoelectric resonators.
For this reason, it is required to further reduce the size of the crystal resonator element itself that can determine the size of the crystal resonator. Conventionally, when producing a quartz crystal vibrating piece, it is common to form a quartz crystal vibrating piece by mechanically forming a quartz crystal plate cut out from a quartz crystal at a predetermined cutting angle. However, machining has a limit in machining accuracy, and it is becoming difficult to produce a finer and smaller quartz crystal resonator element. Therefore, at present, the processing method of the crystal vibrating piece is changing from mechanical processing to a method using a photolithography technique and an etching processing technique.

  However, when using a photolithography technique or an etching process, it is difficult to form a convex shape or a bevel shape on the crystal vibrating piece, and practically it is almost impossible. Therefore, a conventional mounting method in which bumps are arranged in a beveled portion cannot be adopted, and a new mounting method is demanded instead.

  The present invention has been made in view of such circumstances, and its purpose is to mount with high mounting strength while suppressing deterioration of vibration characteristics even when the outer shape is formed by etching. It is to provide a crystal vibrating piece that can be performed.

The present invention provides the following means in order to solve the above problems.
(1) The quartz crystal resonator element according to the present invention is formed on a quartz diaphragm in which an AT-cut quartz plate is formed in a rectangular shape in a plan view by wet etching, and on the front and back main surfaces of the quartz diaphragm. A pair of electrode films and a pair of mountings formed on the pair of electrode films on one main surface of the crystal diaphragm, respectively, to conduct the external electrode and the pair of electrode films and to hold the crystal diaphragm Members, and the crystal diaphragm has an inclined surface inclined at an obtuse angle with respect to the one main surface in at least a part of the side surface, and at least one of the pair of mounting members is It is formed on a ridge line formed between the inclined surface and the one main surface or on an extension line of the ridge line.

  In the quartz crystal resonator element according to the present invention, it is held (mounted) by a pair of mounting members, and the electrode film is electrically connected to the external electrode through the mounting members. Here, when a voltage is applied from the external electrode through the pair of mounting members, the voltage is applied to the pair of electrode films respectively formed on the front and back main surfaces of the crystal diaphragm. Then, the quartz diaphragm is excited and vibrates in thickness. For this reason, the quartz crystal vibrating piece vibrates in a thickness-shear manner while being held by a pair of mounting members.

By the way, the crystal diaphragm is formed by applying a wet etching process to a crystal plate obtained by AT-cutting the crystal. Therefore, unlike machining, it is possible to cope with miniaturization and miniaturization.
In addition, an inclined surface that is inclined at an obtuse angle with respect to one main surface on which the mounting member is provided is formed on a part of the side surface of the crystal diaphragm by wet etching. That is, the inclined surface is formed by utilizing the etching anisotropy unique to quartz. In particular, since this inclined surface is formed at an obtuse angle with respect to one main surface, vibration excited by the electrode film can be attenuated by the inclined surface. That is, the vibration can be attenuated on the ridge line or an extension line of the ridge line.

  Therefore, it is possible to make it difficult to inhibit the excited vibration by forming at least one of the pair of mounting members on the ridgeline or an extension of the ridgeline. Therefore, the quartz crystal resonator element can be mounted while suppressing the deterioration of the vibration characteristics. Moreover, since mounting can be performed using a mounting member as in the conventional case, high mounting strength can be ensured.

(2) The quartz crystal resonator element according to the invention is the quartz crystal resonator element according to the invention, wherein the inclined surface is formed over the entire length of the side surface along the X-axis direction of the quartz crystal. It is formed on the ridgeline.

In the quartz crystal resonator element according to the present invention, since the inclined surface is formed over the entire length of the side surface, it is easy to form the inclined surface during wet etching. Further, since at least one mounting member of the pair of mounting members is formed on the ridgeline, it is difficult to inhibit the excited vibration, and the deterioration of the vibration characteristics can be more effectively suppressed.
Furthermore, since the inclined surface is formed over the entire length of the side surface along the X-axis direction of the quartz crystal,
Contour vibration hardly occurs on the ridgeline. Therefore, it is possible to suppress the thickness-shear vibration from being hindered by the contour vibration, and in this respect as well, it is easy to more effectively suppress the deterioration of the vibration characteristics.

(3) The quartz crystal resonator element according to the invention is the quartz crystal resonator element according to the invention, wherein the inclined surface is formed over the entire length of the side surface along the Z′-axis direction of the quartz crystal, and the mounting member is Both are formed on the ridge line.

In the quartz crystal resonator element according to the present invention, since the inclined surface is formed over the entire length of the side surface, it is easy to form the inclined surface during wet etching. In addition, since both the pair of mounting members are formed on the ridgeline, it is difficult to inhibit the vibration excited by the electrode film, and the deterioration of the vibration characteristics can be more effectively suppressed.
By the way, the phase of the excited vibration is equal to zero on the side surface along the Z′-axis direction of the quartz crystal. And since the inclined surface is formed along this side surface and the pair of mounting members are formed on the ridgeline of the inclined surface, it is easy to suppress the deterioration of the vibration characteristics more effectively.

(4) The quartz crystal resonator element according to the invention is the quartz crystal resonator element according to the invention, wherein the inclined surface is partially formed on the side surface along the X-axis direction of the quartz crystal, and the mounting member is It is formed so that it may be located on one main surface and the extended line of the said ridgeline.

In the quartz crystal resonator element according to the present invention, the inclined surface is not formed over the entire length of the side surface along the X-axis direction, but is formed partially. At least one mounting member of the pair of mounting members is formed not on the ridge line of the inclined surface but on a flat portion on one main surface and on the extension line of the ridge line. Therefore, the mounting member can be formed more stably using the flat portion while suppressing the deterioration of the vibration characteristics, and the mounting quality can be further improved.
Furthermore, since the inclined surface is formed on the side surface along the X-axis direction of the quartz crystal, contour vibration hardly occurs on the ridgeline. Therefore, it is possible to suppress the thickness-shear vibration from being hindered by the contour vibration, and it is easy to suppress the deterioration of the vibration characteristics.

(5) The crystal vibrating piece according to the present invention is characterized in that, in the crystal vibrating piece of the present invention, the electrode film is also formed on the inclined surface.

  In the quartz crystal resonator element according to the present invention, since the electrode film is also formed on the inclined surface, even if the mounting member spreads from the flat portion on one main surface to the inclined surface side during mounting, Conductivity with the electrode film can be ensured. Therefore, the electrical connection between the electrode film and the external electrode can be ensured, the mounting quality can be improved, and stable vibration characteristics can be maintained.

  According to the quartz crystal resonator element according to the present invention, since the outer shape is formed by using etching processing, it is possible to cope with miniaturization and miniaturization, and mounting with high mounting strength while suppressing deterioration of vibration characteristics. It can be performed.

It is a figure for demonstrating embodiment which concerns on this invention, Comprising: It is a disassembled perspective view of the surface mount-type crystal resonator which has a thickness shear vibration piece. It is a perspective view of a rough lumbard stone for explaining a cutting angle of a quartz plate and a coordinate axis of a quartz crystal. It is the perspective view which looked at the thickness sliding vibration piece shown in FIG. 1 from the back side. It is the top view which looked at the thickness shear vibration piece shown in FIG. 3 from the arrow A direction. It is the side view which looked at the thickness shear vibration piece shown in FIG. 4 from the arrow B direction. FIG. 4 is a process diagram for explaining a manufacturing method of the thickness-shear vibrating piece shown in FIG. It is sectional drawing which shows the state of the initial stage which carried out the wet etching process on both surfaces of the quartz plate after the state shown in FIG. FIG. 8 is a cross-sectional view illustrating a state in which wet etching has progressed after the state illustrated in FIG. 7. FIG. 9 is a cross-sectional view illustrating a state in which wet etching has further progressed after the state illustrated in FIG. 8. FIG. 10 is a cross-sectional view showing a state in which an inclined surface is formed by further progressing wet etching after the state shown in FIG. 9. It is a figure which shows the modification of the thickness shear vibration piece which concerns on this invention, Comprising: It is a top view from the back side. It is sectional drawing along CC line of the thickness shear vibration piece shown in FIG. It is the side view which looked at the thickness sliding vibration piece shown in FIG. 11 from the arrow D direction. It is a figure which shows another modification of the thickness sliding vibration piece shown in FIG. It is the side view which looked at the thickness sliding vibration piece shown in FIG. 14 from the arrow E direction. It is a figure which shows another modification of the thickness sliding vibration piece shown in FIG. It is a figure which shows another modification of the thickness sliding vibration piece shown in FIG. It is a figure which shows the modification of the thickness shear vibration piece which concerns on this invention, Comprising: It is a top view from the back side. It is the side view which looked at the thickness sliding vibration piece shown in FIG. 18 from the arrow F direction. FIG. 20 is a diagram illustrating another modification of the thickness-shear vibration piece illustrated in FIG. 19. It is a figure which shows another modification of the thickness sliding vibration piece shown in FIG.

  Hereinafter, embodiments according to the present invention will be described with reference to FIGS. In the present embodiment, a surface-mounted crystal resonator having a thickness-shear resonator element (crystal resonator element) will be described as an example.

As shown in FIG. 1, the crystal resonator 1 according to the present embodiment is formed in a box shape in which a base substrate 2 and a lid substrate 3 are laminated in two layers. 4 is mounted. FIG. 1 is an exploded perspective view of the crystal unit 1.
The thickness-sliding vibration piece 4 is mainly composed of a crystal diaphragm 10 and a pair of electrode films 20 formed on the front and back main surfaces of the crystal diaphragm 10.

As shown in FIG. 2, the quartz diaphragm 10 is formed by AT-cutting the quartz lambard ore 6 in which the coordinate axes of the quartz crystal are defined by the X axis, the Y axis, and the Z axis (the front and back main surfaces are rotated from the Z axis around the X axis). The quartz plate 7 obtained by cutting the lens so as to have an angle of about 35 degrees 15 minutes in the counterclockwise direction is formed into a rectangular shape in plan view by wet etching after that.
FIG. 2 is a perspective view of the lumbar raw stone 6 for explaining the cutting angle of the quartz plate 7 and the coordinate axes of the quartz crystal. Further, in the present embodiment, the Z ′ axis is a crystal axis in a direction orthogonal to the X axis on the front and back main surfaces of the crystal diaphragm 10 as shown in FIG. 1, and the Y ′ axis is the X axis and the Z axis. 'A crystal axis perpendicular to the axis.

The crystal diaphragm 10 will be described in detail.
As shown in FIGS. 3 to 5, the quartz crystal plate 10 of the present embodiment is wet so that the long side extends along the X-axis direction and the short side extends along the Z′-axis direction. It is a diaphragm formed into a rectangular shape in plan view by etching.
Both the front and back main surfaces 10a and 10b (the front-side main surface (the other main surface) 10a and the back-side main surface (the one main surface) 10b) of the quartz crystal plate 10 are flat surfaces.

  FIG. 3 is a perspective view of the thickness-shear vibration piece 4 shown in FIG. 1 as viewed from the back side. 4 is a plan view of the thickness-shear vibration piece 4 shown in FIG. FIG. 5 is a side view of the thickness-shear vibration piece 4 shown in FIG.

Further, since the quartz diaphragm 10 is formed in a rectangular shape in plan view, it has four side surfaces. That is, it has two long side surfaces along the X-axis direction and two short side surfaces along the Z′-axis direction.
Among these, the side surface along the X-axis direction is an inclined surface (hereinafter referred to as an inclined surface 11) inclined at an obtuse angle with respect to the front and back main surfaces 10 a and 10 b over the entire length. At this time, one inclined surface 11 is provided on the + side in the Z′-axis direction on the main surface 10a on the front side, and the other inclined surface 11 is on the − side in the Z′-axis direction on the main surface 10b on the back side. Is provided. These inclined surfaces 11 are m-planes that are natural surfaces of quartz crystals, and an angle θ (see FIG. 5) formed with the front and back main surfaces 10a and 10b is about 150 degrees.

The pair of electrode films 20 are composed of an excitation electrode 21, an extraction electrode 22, and a mount electrode 23, respectively, as shown in FIGS.
Among these, the excitation electrode 21 is formed in the substantially center part of the front and back main surfaces 10a and 10b of the quartz crystal plate 10, and is formed so as to face each other with the quartz plate 10 interposed therebetween. In addition, mount electrodes 23 are formed on the end portions (the negative side in the X-axis direction) of the front and back main surfaces 10a and 10b of the quartz crystal plate 10 at intervals along the short side. At this time, the mount electrode 23 formed on the front-side main surface 10a and the mount electrode 23 formed on the back-side main surface 10b are electrically connected via the side electrode 23a formed on the inclined surface 11. Has been.

Of the mount electrodes 23, one mount electrode 23 is electrically connected to one excitation electrode 21 formed on the front main surface 10 a via the extraction electrode 22, and the other mount electrode 23 is an extraction electrode. 22 is electrically connected to the other excitation electrode 21 formed on the main surface 10 b on the back side.
The electrode film 20 composed of the excitation electrode 21, the extraction electrode 22 and the mount electrode 23 is a single layer film such as gold, or a laminate in which a metal layer such as gold is laminated on a metal such as chromium. It is formed of a film.

The thickness-shear vibrating piece 4 configured as described above is formed on the upper surface of the base substrate 2 as shown in FIG. 1 using a pair of mounting members 25 such as bumps and conductive adhesives shown in FIGS. Mounted (held). More specifically, with respect to the inner electrode (external electrode) 30 formed on the upper surface of the base substrate 2, the pair of mount electrodes 23 formed on the main surface 10 b on the back side of the quartz crystal plate 10 is a pair of mounting members. 25 in a state where they are in contact with each other.
Accordingly, the thickness shear vibrating piece 4 is mechanically held on the upper surface of the base substrate 2, and the inner electrode 30 and the mount electrode 23 are electrically connected to each other.

By the way, the above-described pair of mounting members 25 are respectively formed on the pair of mount electrodes 23 on the main surface 10b on the back side of the crystal diaphragm 10, and as described above, the inner electrode 30 and the mount electrode which are also external electrodes 23 are connected to each other, and the quartz diaphragm 10 is mechanically held.
In addition, one mounting member 25 of the pair of mounting members 25 is formed so as to straddle the ridge line E formed between the main surface 10 b on the back side of the quartz crystal plate 10 and the inclined surface 11. The other mounting member 25 is formed on a flat portion on the main surface 10 b on the back side of the crystal diaphragm 10.

The base substrate 2 is a transparent substrate made of, for example, soda lime glass, and is formed in a plate shape having a rectangular shape in plan view. Similar to the base substrate 2, the lid substrate 3 is a transparent substrate made of, for example, soda lime glass, and is formed in a plate shape with a size that can be superimposed on the base substrate 2.
In addition, a rectangular recess 2 a in which the thickness shear vibration piece 4 is accommodated is formed on the side of the base substrate 2 where the lid substrate 3 is joined (surface to which the lid substrate 3 is joined). The recess 2 a is a cavity recess that becomes a cavity C that accommodates the thickness-shear vibration piece 4 when the substrates 2 and 3 are overlapped.
The base substrate 2 is anodically bonded to the lid substrate 3 with the concave portion 2a facing the lid substrate 3 side. A bonding film 31 for anodic bonding is formed on the bonding surface of the base substrate 2 so as to surround the recess 2a.

  Further, the inner electrode 30 described above is electrically connected to a pair of external electrodes (not shown) formed on the lower surface of the base substrate 2 using a through hole (not shown) penetrating the base substrate 2. At this time, one external electrode is electrically connected to one mount electrode 23 of the thickness-shear vibrating piece 4 via one inner electrode 30. The other external electrode is electrically connected to the other mount electrode 23 of the thickness-shear vibrating piece 4 via the other inner electrode 30.

When the crystal resonator 1 configured as described above is operated, a predetermined drive voltage is applied to the external electrode formed on the base substrate 2. As a result, a voltage can be applied to the excitation electrode 21 of the thickness-shear vibration piece 4 via the mounting member 25 and the mount electrode 23, and thickness-shear vibration can be caused in a state of being mounted by the mounting member 25.
The thickness shear vibration can be suitably used as, for example, a control having an oscillation frequency in the MHz band, a vibration source for a communication device, or the like.

Next, a method for manufacturing the above-described thickness shear vibrating piece 4 will be described below.
First, after preparing a lumbard raw stone 6 shown in FIG. 2 which is a raw crystal of quartz, an angle measurement for performing AT cut is performed by an X-ray diffraction method or the like. Next, the quartz plate 7 is produced by AT-cutting the lumbar raw stone 6 at the measured cutting angle. Next, the quartz plate 7 is appropriately lapped and adjusted to a desired thickness.

Next, as shown in FIG. 6, a process of forming a mask M for performing wet etching on the front and back main surfaces 7a and 7b of the crystal plate 7 is performed.
Specifically, first, chromium is formed on the front and back main surfaces 7a and 7b of the crystal plate 7 to form a Cr film, and then gold is formed on the Cr film to overlap the Au film. Then, the Cr film and the Au film are etched by a photolithographic technique to form a mask M as shown in FIG.
At this time, in the present embodiment, the mask M formed on the front main surface 7a is shifted by a predetermined amount (several μm) H in the Z′-axis direction with respect to the mask M formed on the back main surface 7b. Form.

Next, the quartz plate 7 is wet-etched from both sides. Then, due to the etching anisotropy peculiar to quartz, the exposed surface of the unmasked quartz plate 7 has an m-plane 35 that is a natural plane of the quartz crystal and a crystal plane 36 other than that as shown in FIG. It begins to appear. That is, on the front side of the crystal plate 7, the m-plane 35 appears on the + side in the Z′-axis direction, and the crystal plane 36 begins to appear on the − side in the Z′-axis direction. On the other hand, on the back side of the crystal plate 7, the crystal plane 36 appears on the + side in the Z′-axis direction and the m-plane 35 begins to appear on the − side in the Z′-axis direction, in point symmetry with the front side.
Then, the etching progresses as time passes as shown in FIG. 8, and the unmasked portion is completely removed as shown in FIG. 9 as further progressing, and finally, as shown in FIG. Thus, the m-plane 35 remains. Thereby, this m surface 35 can be utilized as the inclined surface 11.

  At this time, the crystal plate 7 can be formed in a rectangular shape in plan view, and the crystal diaphragm 10 shown in FIG. 1 can be obtained. In particular, the inclined surface 11 can be formed over the entire length of the side surface along the X-axis direction. Finally, a pair of electrode films 20 including the excitation electrode 21, the extraction electrode 22, and the mount electrode 23 are formed on the outer surface of the manufactured quartz crystal plate 10 by using a photolithography technique or the like. Thereby, the thickness shear vibration piece 4 shown in FIG. 1 can be obtained.

As described above, the quartz diaphragm 10 of the present embodiment is formed by applying wet etching to the quartz plate 7, and therefore, unlike machining, it can cope with miniaturization and miniaturization. Is possible.
In addition, an inclined surface 11 is formed on the side surface on the long side along the X-axis direction of the crystal vibrating plate 10 by utilizing etching anisotropy peculiar to crystal. In particular, since the inclined surface 11 is formed at an obtuse angle with respect to the front and back main surfaces 10a and 10b, the vibration excited by the excitation electrode 21 can be attenuated by the inclined surface 11. That is, vibration can be attenuated on the ridge line E.

  Therefore, by forming one mounting member 25 on the ridge line E, it is possible to make it difficult to inhibit the excited vibration. Therefore, the thickness-shear vibrating piece 4 can be mounted while suppressing a decrease in vibration characteristics. Moreover, since mounting can be performed using the mounting member 25 as in the conventional case, high mounting strength can be ensured.

As described above, according to the thickness-shear vibrating piece 4 of the present embodiment, since the outer shape is formed by using etching processing, it is possible to cope with miniaturization and miniaturization, and suppress deterioration of vibration characteristics. However, mounting can be performed with high mounting strength.
Furthermore, in this embodiment, since the inclined surface 11 is formed over the entire length of the side surface along the X-axis direction, contour vibration hardly occurs on the ridge line E. Therefore, it is possible to prevent the thickness-shear vibration from being hindered by the contour vibration, and in this respect also, it is easy to more effectively suppress the deterioration of the vibration characteristics.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the surface mount type has been described as an example of the crystal resonator 1, but a cylinder package type may be used.

  In the above-described embodiment, both side surfaces along the X-axis direction are the inclined surfaces 11, but one side surface may be the inclined surface 11 that is inclined with respect to the main surface 10 b on the back side of the crystal diaphragm 10. . Even in this case, mounting can be performed with high mounting strength while suppressing a decrease in vibration characteristics. However, it is preferable that both the side surfaces along the X-axis direction be the inclined surfaces 11 in that the contour vibration can be effectively suppressed.

Moreover, in the said embodiment, although the inclined surface 11 was formed over the full length of the side surface along a X-axis direction, you may form partially.
For example, as shown in FIGS. 11 to 13, an inclined surface 11 inclined at an obtuse angle with respect to the main surface 10 b on the back side of the crystal diaphragm 10 is partially formed on one side surface along the X-axis direction. The thickness-shear vibrating piece (quartz vibrating piece) 40 formed may be used.
At this time, one mounting member 25 is on the main surface 10b on the back side of the crystal diaphragm 10, and is formed between the partially formed inclined surface 11 and the main surface 10b on the back side. It is formed so as to be located on an extension line of E. That is, one mounting member 25 is formed not on the ridge line E of the inclined surface 11 but on the extended line of the ridge line E while riding on the flat portion (mounting flat surface portion) of the main surface 10b on the back side.

  Therefore, one mounting member 25 can be formed more stably using the flat portion while suppressing the deterioration of the vibration characteristics, and the mounting quality can be improved. Moreover, since the weight at the time of mounting can be equally loaded with respect to both of a pair of mounting members 25, mounting quality can be improved also in this point.

  When the thickness-shear vibrating piece 40 is configured as described above, the X-axis is also applied to the inclined surface 11 inclined with respect to the main surface 10a on the front side of the crystal vibrating plate 10, as shown in FIGS. You may form partially on the side surface along a direction. By doing so, both the front and back of the negative side end in the X-axis direction where the pair of mounting members 25 are formed can be flattened, so that the mechanical strength of the crystal diaphragm 10 can be increased, Mount reliability at the time of mounting can be improved.

By the way, it is generally known that quartz has “optical rotation” and is divided into a right crystal and a left crystal depending on how crystal planes appear. When the crystal plate 7 AT cut from the right crystal is wet-etched, a notch 41 appears at the corner of the crystal diaphragm 10 due to the crystal structure of the crystal as shown in FIG. It has been known.
Therefore, when the inclined surface 11 is partially formed, it is preferable to use a corner portion having a small cutout portion 41 as a mounting plane portion.
In addition, when the crystal plate 7 AT-cut from the left crystal is subjected to wet etching, the cutout portion 41 at the corner on the negative side in the X-axis direction of the crystal vibration plate 10 becomes small. Therefore, in this case, the inclined surface 11 or the like may be formed in accordance with the position of the notch 41. That is, when the left crystal is used, it is preferable that the negative side in the X-axis direction of the crystal diaphragm 10 is a mounting plane part as shown in FIG. In the case of the right crystal, on the contrary, it is preferable to set the + side in the X-axis direction as the mounting plane part.

When the inclined surface 11 is partially formed, it is preferable to form the mount electrode 23 on the inclined surface 11 as shown in FIG.
By doing so, even if the mounting member 25 spreads from the flat portion of the main surface 10b on the back side to the inclined surface 11 side during mounting, electrical connection with the mount electrode 23 can be ensured. Therefore, the electrical continuity between the mount electrode 23 and the inner electrode 30 can be ensured, the mounting quality can be improved, and stable vibration characteristics can be maintained.

In the above-described embodiment, the inclined surface 11 is formed on the side surface along the X-axis direction, but may be formed on the side surface along the Z′-axis direction.
For example, as shown in FIGS. 18 and 19, the inclined surface 11 may be formed over the entire length of the side surface along the Z′-axis direction. In this case, the pair of mounting members 25 can be formed together on the ridge line E between the inclined surface 11 and the main surface 10b on the back side.
When the thickness-shear vibrating piece (quartz crystal vibrating piece) 50 is configured in this way, since both the pair of mounting members 25 are formed on the ridge line E, it is more difficult to inhibit the excited vibration and vibration characteristics. Can be more effectively suppressed.

  In particular, it is known that the vibration excited by the excitation electrode 21 has a phase equal to zero on the side surface along the Z′-axis direction. Therefore, by forming the inclined surface 11 along this side surface and forming the pair of mounting members 25 on the ridge line E of the inclined surface 11, it is easy to more effectively suppress the deterioration of the vibration characteristics.

  Of the side surfaces along the Z′-axis direction, the side surface positioned on the + side in the X-axis direction may be a vertical surface as shown in FIG. 20, or may be formed as a gable as shown in FIG. It doesn't matter. In either case, the same effects can be achieved.

E ... Ridge line 4, 40, 50 ... Thickness sliding vibration piece (crystal vibration piece)
7 ... Crystal plate 10 ... Crystal plate 10b ... Main surface on the back side (one main surface of the crystal plate)
DESCRIPTION OF SYMBOLS 11 ... Inclined surface 20 ... Electrode film 25 ... Mounting member 30 ... Inner electrode (external electrode)

Claims (2)

A quartz crystal plate in which an AT-cut quartz plate is formed in a rectangular shape in plan view by wet etching;
A pair of electrode films respectively formed on the front and back main surfaces of the crystal diaphragm;
A pair of mounting members that are respectively formed on the pair of electrode films on one main surface of the crystal diaphragm, and that conduct the external electrode and the pair of electrode films and hold the crystal diaphragm,
The quartz crystal plate has an inclined surface that is inclined at an obtuse angle with respect to the one main surface as a part of the side surface,
At least one of the pair of mounting members is formed on the one main surface and on an extension line of a ridge line formed between the inclined surface and the one main surface,
The inclined surface is formed along the X-axis direction of the quartz crystal. The quartz crystal resonator element according to claim 1 ,
The quartz crystal resonator element, wherein the electrode film is also formed on the inclined surface.

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