JP2018110292A - Piezoelectric vibrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric vibrator capable of making a piezoelectric vibration piece come into contact with a protrusion part without affecting a vibration characteristic of the piezoelectric vibration piece.SOLUTION: A piezoelectric vibrator comprises: a piezoelectric vibration piece 10 formed of an AT cut quartz board; and a mounting board 72 on which the piezoelectric vibration piece 10 is mounted via a mounting member 8. A protrusion part 86 is formed from a bottom face 71a of the mounting board 72 toward the piezoelectric vibration piece 10. The piezoelectric vibration piece 10 comprises: mesa parts 23, 24 swelling in the thickness direction of a piezoelectric plate 11; and a projection part 82 provided on an outer periphery part 28. The projection part 82 is arranged so as to at least overlap part of the protrusion part 86 in the thickness direction of the piezoelectric plate 11.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a piezoelectric vibrator.

In the piezoelectric vibrator, a piezoelectric vibrating piece is mounted on a package with a mounting member. When the piezoelectric vibrator receives an impact, it is considered that the piezoelectric vibrating piece swings relatively large and comes into contact with the bottom surface of the package, and the vibration characteristics fluctuate relatively large. Among piezoelectric vibrators, there are known ones in which a pillow portion (hereinafter referred to as a protrusion) is provided on the bottom surface of a package and a piezoelectric vibrating piece is brought into contact with the protrusion.
The protrusion is provided so as to avoid the excitation electrode and to contact the tip of the piezoelectric vibrating piece. Accordingly, the protrusions do not affect the vibration characteristics of the piezoelectric vibrating piece (see, for example, Patent Document 1).

JP 2000-332561 A

  However, it is conceivable that with the miniaturization of the piezoelectric vibrating piece, it becomes difficult to secure the portion where the protrusion is provided in the piezoelectric vibrating piece, and it becomes difficult to maintain the crystal impedance (hereinafter referred to as the CI value). For this reason, there has been a demand for practical application of a technique that does not affect the vibration characteristics of the piezoelectric vibrating piece when the piezoelectric vibrating piece comes into contact with the protrusion.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a piezoelectric vibrator capable of bringing a piezoelectric vibrating piece into contact with a protrusion without affecting the vibration characteristics of the piezoelectric vibrating piece. Is to provide.

  In order to solve the above problems, a piezoelectric vibrator according to one aspect of the present invention includes a piezoelectric vibrating piece formed of an AT-cut quartz substrate, the piezoelectric vibrating piece mounted via a mounting member, and the piezoelectric vibrator. And a package having a protrusion protruding toward the vibrating piece, and the piezoelectric vibrating piece is mounted at one end in a direction perpendicular to the thickness direction of the piezoelectric vibrating piece and bulges in the thickness direction. A mesa portion and an overhang portion provided on the outer peripheral side of the mesa portion, the overhang portion being provided on the other end side opposite to the one end of the piezoelectric vibrating piece, and It is disposed so as to overlap at least a part of the protrusion in the thickness direction.

According to this configuration, the projecting portion is formed on the package, and the overhang portion is overhanged from the outer peripheral side of the mesa portion. The overhanging portion is disposed so as to overlap at least a part of the protrusion in the thickness direction of the piezoelectric vibrating piece. Therefore, when the piezoelectric vibrator receives an impact, the overhanging portion can be brought into contact with the protruding portion at a position away from the mesa portion. Thereby, it is possible to prevent the vibration characteristics of the piezoelectric vibrating piece from being affected when the projecting portion comes into contact with the protruding portion.
By projecting the projecting portion from the outer peripheral side of the mesa portion, particularly in a small piezoelectric vibrating piece, the projecting portion can be brought into contact with the protruding portion at a position away from the mesa portion. Accordingly, even a small piezoelectric vibrating piece can be prevented from affecting the vibration characteristics of the piezoelectric vibrating piece.

  Further, one end side of the piezoelectric vibrator was mounted with a mounting member, and a protruding portion was provided on the other end side of the piezoelectric vibrator. Therefore, when the piezoelectric vibrator receives an impact, the displacement on the other end side of the piezoelectric vibrator can be suppressed. Thereby, the displacement of the piezoelectric vibrator can be efficiently suppressed, and the vibration characteristics of the piezoelectric vibrating piece can be prevented from being affected.

In the above aspect, the projecting portion may be gradually tapered in a direction away from the mesa portion in a plan view as viewed from the thickness direction.
According to this configuration, the overhanging portion can be reduced in weight by forming the overhanging portion in a plan view. Thereby, propagation of vibration to the overhanging portion can be suppressed.

  In the above aspect, the piezoelectric vibrating piece may have an outer peripheral portion that surrounds the mesa portion, and the overhang portion may be formed to have the same thickness as the outer peripheral portion.

  According to this configuration, the protruding portion is formed to have the same thickness as the outer peripheral portion of the piezoelectric vibrator. In the piezoelectric vibrator, the mesa portion is bulged in the thickness direction of the piezoelectric vibrating piece. Accordingly, the outer peripheral portion has a smaller thickness dimension than the mesa portion. Thereby, the overhang | projection part can be made lightweight by forming an overhang | projection part in the same thickness dimension as an outer peripheral part. Thereby, propagation of vibration to the overhanging portion can be suppressed.

In the above aspect, the piezoelectric vibrating piece has an outer peripheral portion surrounding the periphery of the mesa portion,
The protruding portion may be formed with a thickness dimension larger than that of the outer peripheral portion.

  According to this configuration, the overhanging portion is formed to have a larger thickness dimension than the outer peripheral portion of the piezoelectric vibrator. The height dimension of the protrusion can be kept small. Therefore, the protruding portion can be provided in the vicinity of the inner wall of the package, and the overhanging portion can be further separated from the vibrating portion. Thereby, propagation of vibration to the overhanging portion can be suppressed.

  In the above aspect, the mesa portion may have an inclined surface that is inclined from the outer peripheral edge of the mesa portion toward the center of the piezoelectric vibrating piece.

According to this configuration, the mesa portion includes the inclined surface 26, and the inclined surface 26 is inclined from the outer peripheral edge of the mesa portion toward the center of the piezoelectric vibrating piece. Therefore, the mesa inclined surface can be arranged at a position away from the overhanging portion. Thereby, it can suppress that an overhang | projection part contacts an inclined surface.
Furthermore, the inclined surface of the mesa portion was inclined toward the center of the piezoelectric vibrating piece. Therefore, an inclined surface is formed between the top surface of the mesa portion and the surface of the protruding portion that faces the top surface. Thereby, compared with the case where a 90-degree level | step difference is formed between a top surface and the surface which faces a top surface among protrusions, between a top surface and the surface which faces a top surface among protrusions. It can be connected gently. Therefore, it can suppress that an unnecessary vibration is induced in the boundary part of the top surface of a mesa part, and an inclined surface. As a result, the CI value can be reduced and the vibration characteristics can be improved.

In the above aspect, the mesa portion has a top surface surrounded by the inclined surface, and the projecting portion has an end surface on the one end side provided on the other end side of the piezoelectric vibrating piece from the top surface. May be.
According to this configuration, the end surface on one end side of the overhang portion is provided on the other end side of the piezoelectric vibrating piece from the top surface of the mesa portion. Therefore, the overhanging portion can be separated from the top surface. Thereby, an overhang | projection part can be separated from a top surface and propagation of the vibration to an overhang | projection part can be suppressed.

  In the above aspect, the piezoelectric vibrating piece includes a vibrating portion having an outer peripheral portion formed around the mesa portion, and the vibrating portion is a rectangular plate whose longitudinal direction is the Z′-axis direction of the AT-cut quartz crystal substrate. It may be formed in a shape.

  According to this configuration, a low CI value can be maintained even when the piezoelectric vibrating piece is downsized. That is, the AT-cut quartz crystal substrate is composed of an X axis and a Z ′ axis. Under such a configuration, when the AT-cut quartz substrate is undergoing thickness shear vibration, electric polarization occurs in the X axis and the Z ′ axis. Electric polarization is a charge bias, which is sinusoidal on the X axis and linear on the Z ′ axis. By setting the Z ′ axis in which the electric polarization is linear to the longitudinal direction, the side where the strongest charge is generated can be lengthened. The CI value becomes lower as the region where the strong charge is generated becomes wider. Therefore, a lower CI value can be maintained by setting the Z ′ axis in the longitudinal direction, and more excellent vibration characteristics can be obtained.

  In the above aspect, the piezoelectric vibrating piece includes a vibrating portion having an outer peripheral portion formed around the mesa portion, and a protruding portion protruding from the vibrating portion in a direction orthogonal to the thickness direction. And the protrusion may be attached to the mounting member.

The protruding portion protruded from the vibrating portion in a direction orthogonal to the thickness direction, and the protruding portion was attached to the mounting member. Thereby, a mounting member can be separated from a vibration part and the outstanding vibration characteristic can be acquired.
By the way, the thickness shear vibration, which is the main vibration mode of the AT-cut quartz substrate, is a vibration greatly displaced in the X-axis direction. According to this configuration, by arranging the pair of protrusions along the Z′-axis direction orthogonal to the X-axis direction where the displacement of the vibration part is large, the protrusions fixed to the package via the mounting member are The displacement of the vibrating part in the X-axis direction is not hindered. Thereby, generation | occurrence | production of an unnecessary vibration can be suppressed in a protrusion part. Therefore, more excellent vibration characteristics can be obtained.

According to one aspect of the present invention, the protruding portion is formed on the bottom surface of the package, and the protruding portion is extended from the vibrating portion of the piezoelectric vibrating piece. Therefore, the overhanging portion can be brought into contact with the protrusion at a position away from the vibrating portion. Thereby, it is possible to prevent the vibration characteristics of the piezoelectric vibrating piece from being affected when the projecting portion comes into contact with the protruding portion.
By projecting the overhanging portion from the vibrating portion of the piezoelectric vibrating piece, it is possible to prevent the vibration characteristics of the piezoelectric vibrating piece from being affected particularly in a small piezoelectric vibrating piece.

1 is an exploded perspective view of a piezoelectric vibrator according to a first embodiment of the present invention. 1 is a plan view of a piezoelectric vibrator according to a first embodiment of the present invention. It is sectional drawing in the III-III line of FIG. It is a top view which shows the piezoelectric vibrating piece which concerns on 2nd Embodiment of this invention. It is a top view which shows the piezoelectric vibrating piece which concerns on 3rd Embodiment of this invention. It is a top view which shows the piezoelectric vibrating piece which concerns on 4th Embodiment of this invention. It is a side view which shows the piezoelectric vibrating piece which concerns on 5th Embodiment of this invention. It is a top view which shows the piezoelectric vibrating piece which concerns on 6th Embodiment of this invention. It is a top view which shows the piezoelectric vibrating piece which concerns on 7th Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is an exploded perspective view of the piezoelectric vibrator 1 according to the first embodiment. FIG. 2 is a plan view of the piezoelectric vibrator 1 according to the first embodiment. FIG. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 2 shows a state in which a sealing plate 73 described later is removed.
As shown in FIG. 1, the piezoelectric vibrator 1 includes a piezoelectric vibrating piece 10 and a package 70 on which the piezoelectric vibrating piece 10 is mounted. The piezoelectric vibrating piece 10 is a piezoelectric vibrating piece 10 that vibrates in a thickness-slip mode. The piezoelectric vibrating piece 10 is formed by a piezoelectric plate 11 that forms the outer shape of the piezoelectric vibrating piece 10 and an electrode film 12 formed on the outer surface of the piezoelectric plate 11.

  The piezoelectric plate 11 is formed of an AT cut quartz substrate. Here, the AT cut refers to the X axis relative to the Z axis among the three crystal axes of the electric axis (X axis), the mechanical axis (Y axis), and the optical axis (Z axis), which are crystal axes of artificial quartz. This is a processing method of cutting out in a direction (Z′-axis direction) inclined around 35 degrees and 15 minutes. The piezoelectric vibrating piece 10 having the piezoelectric plate 11 cut out by the AT cut has an advantage that the frequency temperature characteristic is stable, the structure and shape are simple, the processing is easy, and the CI value is low. In the following description, the XY′Z ′ coordinate system is used when describing the configuration of each figure. In this XY′Z ′ coordinate system, the Y ′ axis is an axis orthogonal to the X axis and the Z ′ axis. In the X-axis direction, the Y′-axis direction, and the Z′-axis direction, the arrow direction in the figure is defined as a + direction, and the direction opposite to the arrow is described as a − direction.

The piezoelectric plate 11 includes a vibrating part 20, a projecting part (first projecting part 31 and second projecting part 32), and a projecting part 82 (first projecting part 82A and second projecting part 82B). ing.
The piezoelectric vibrating piece 10 bulges outward in the Y′-axis direction on the front surface 21 facing the Y′-axis direction + side and the back surface 22 facing the Y′-axis direction − side of the vibration unit 20 and becomes a vibration region. It is a so-called mesa type having a mesa portion (a front surface mesa portion 23 and a back surface mesa portion 24 (see FIG. 3)).

As shown in FIG. 2, the vibrating section 20 is formed in a rectangular plate shape having the Y′-axis direction as the thickness direction and the Z′-axis direction as the longitudinal direction. The vibration unit 20 includes a front surface mesa portion 23 formed at the center portion of the front surface 21, a back surface mesa portion 24 (see also FIG. 3) formed at the center portion of the back surface 22, and around each mesa portion 23, 24. And a rectangular frame-shaped outer peripheral portion 28 formed in a uniform thickness.
The plan view refers to a state viewed from the thickness direction of the piezoelectric vibrating piece 10.

  The surface mesa portion 23 bulges in the Y′-axis direction + side with respect to the outer peripheral portion 28. The surface mesa portion 23 is formed in a quadrangular frustum shape. The surface mesa portion 23 has a top surface 25 and an inclined surface 26 surrounding the top surface 25. The top surface 25 is formed in a rectangular shape whose longitudinal direction is the Z′-axis direction in plan view. The top surface 25 is a flat surface extending in a direction orthogonal to the Y′-axis direction. The inclined surface 26 connects the outer peripheral edge of the top surface 25 and the inner peripheral edge of the main surface on the Y′-axis direction + side in the outer peripheral portion 28. The inclination angle of the inclined surface 26 with respect to the top surface 25 is, for example, 30 ° or less.

As shown in FIG. 3, the back surface mesa portion 24 bulges in the Y′-axis direction − side with respect to the outer peripheral portion 28. The back surface mesa portion 24 is formed to be point-symmetric with the front surface mesa portion 23 and is formed at the same position as the front surface mesa portion 23 in plan view.
In addition, the same code | symbol as the top surface 25 and the inclined surface 26 of the surface mesa part 23 is attached | subjected and demonstrated to the top surface and inclined surface of the back surface mesa part 24. FIG.

Returning to FIG. 2, the protruding portions (the first protruding portion 31 and the second protruding portion 32) protrude from the vibrating portion 20 toward the X axis direction + side. Each protrusion 31 and 32 is formed side by side in the Z′-axis direction. The protrusions 31 and 32 are formed at both ends of the vibrating portion 20 in the Z′-axis direction at the end on the + X-axis direction side.
The first protrusion 31 is formed in a parallelogram shape in plan view. The first projecting portion 31 is in a direction perpendicular to the Y′-axis direction from the portion facing the X-axis direction + side at the corner portion located on the X-axis direction + side and the Z′-axis direction + side of the vibrating portion 20. It protrudes. Specifically, the first protrusion 31 is located at the end on the side surface 28d side facing the Z′-axis direction + side of the outer peripheral portion 28 in the base end 11a of the piezoelectric plate 11 (that is, one end of the piezoelectric plate 11). Is formed. The first protrusion 31 is inclined in the Z′-axis direction + side as it goes from the base end 11a toward the X-axis direction + side in plan view. For example, the first protruding portion 31 is formed to have the same thickness as the outer peripheral portion 28 of the vibrating portion 20.

  The 2nd protrusion part 32 is formed in the parallelogram shape in planar view. The second projecting portion 32 extends in a direction orthogonal to the Y′-axis direction from the portion facing the X-axis direction + side at the corner portion located on the X-axis direction + side and the Z′-axis direction − side of the vibration unit 20. It protrudes. Specifically, the second projecting portion 32 is formed at the end portion of the base end 11 a of the piezoelectric plate 11 on the side surface 28 e side facing the Z′-axis direction-side of the outer peripheral portion 28. The second projecting portion 32 is inclined toward the Z′-axis direction − side from the base end 11a toward the X-axis direction + side in plan view. For example, the second protrusion 32 is formed to have the same thickness as the outer peripheral portion 28, similar to the first protrusion 31.

  The electrode film 12 vibrates the piezoelectric plate 11 through thickness. The electrode film 12 includes an excitation electrode (the first excitation electrode 61 and the second excitation electrode 62), a mount electrode (the first mount electrode 63 and the second mount electrode 64), and a lead wiring (the first lead wiring 65 and the second lead electrode). Routing wiring 66). The electrode film 12 is formed of a single layer film such as gold, or a laminated film using chromium or the like as a base layer and gold or the like as an upper layer.

The first excitation electrode 61 is disposed on the top surface 25 of the surface mesa portion 23. The first excitation electrode 61 is formed in a rectangular shape in plan view.
The second excitation electrode 62 is disposed on the top surface 25 (see FIG. 3) of the back surface mesa portion 24. The second excitation electrode 62 is formed in a rectangular shape in plan view and overlaps the first excitation electrode 61 in the Y′-axis direction.

The first mount electrode 63 is disposed over the entire surface of the first protrusion 31.
The second mount electrode 64 is disposed over the entire surface of the second protrusion 32.
The first routing wiring 65 connects the first excitation electrode 61 and the first mount electrode 63 on the surface 21 of the vibration unit 20.
The second routing wiring 66 connects the second excitation electrode 62 and the second mount electrode 64 on the back surface 22 of the vibration unit 20.

Overhang portions 82 (first overhang portion 82A and second overhang portion 82B) are overhanging from the vibrating portion 20 in the Z′-axis direction. The overhang portion 82 includes a first overhang portion 82A and a second overhang portion 82B that are formed side by side in the Z′-axis direction. Of the side surface 28d facing the Z′-axis direction + side of the outer peripheral portion 28, the first overhanging part 82A projects from the end on the X-axis direction − side to the Z′-axis direction + side.
Of the side surface 28e facing the Z′-axis direction − side of the outer peripheral portion 28, the second overhanging part 82B projects from the end on the X-axis direction − side to the Z′-axis direction + side.
The first overhanging portion 82A and the second overhanging portion 82B will be described in detail later.

  As shown in FIG. 1, the package 70 includes a mounting substrate 72 having a recess 71 that accommodates the piezoelectric vibrating piece 10, and a sealing plate 73 that closes the recess 71 of the mounting substrate 72.

  The mounting substrate 72 is formed in a box shape that opens toward the Y′-axis direction + side. The mounting substrate 72 is configured by laminating a first substrate 74, a second substrate 75, and a third substrate 76 made of a ceramic material in the Y′-axis direction. In addition, as a ceramic material used for each board | substrate 74-76, it is possible to use HTCC made from alumina, LTCC made from glass ceramics, etc., for example. HTCC is High Temperature Co-Fired Ceramic. LTCC is Low Temperature Co-Fired Ceramic.

The first substrate 74 is formed in a rectangular shape whose longitudinal direction is the Z′-axis direction in a plan view as viewed from the Y′-axis direction. The main surface (hereinafter referred to as “upper surface”) of the first substrate 74 on the Y′-axis direction + side forms a bottom surface 71 a of the recess 71. Projection portions 86 (first projection portion 86A and second projection portion 86B) are formed on the bottom surface 71a.
A pair of external electrodes (not shown) is formed on the main surface of the first substrate 74 on the Y′-axis direction − side. The external electrode is composed of a single layer film made of a single metal formed by, for example, vapor deposition or sputtering, or a laminated film in which different metals are stacked.
Hereinafter, the bottom surface 71a of the recess 71 is referred to as “the bottom surface 71a of the package 70”.

  The protruding portion 86 includes a first protruding portion 86A that protrudes from the bottom surface 71a toward the first protruding portion 82A, and a second protruding portion 86B that protrudes from the bottom surface 71a toward the second protruding portion 82B. Yes. 86 A of 1st protrusion parts are formed in a column shape, and are arrange | positioned so that a part may overlap with 82 A of 1st overhang | projection parts. Similarly to the first protrusion 86A, the second protrusion 86B is formed in a columnar shape and is disposed so as to partially overlap the second overhang 82B.

The second substrate 75 is integrally bonded to the upper surface of the first substrate 74 by sintering or the like. The second substrate 75 includes a frame portion 77 and a pair of mounting portions 78 (a first mounting portion 78A and a second mounting portion 78B).
The frame portion 77 is formed in a rectangular frame shape having a planar view outer shape viewed from the Y′-axis direction and having a size equivalent to that of the first substrate 74.

  The pair of mounting portions 78 are each formed in a rectangular shape in plan view so as to protrude inward from corners on both sides in the X-axis direction and the Z′-axis direction of the frame portion 77. The mounting portion 78 includes a first mounting portion 78A located on the Z′-axis direction + side and a second mounting portion 78B located on the Z′-axis direction − side. An electrode pad 79 is formed on the mounting portion 78. Similarly to the external electrode (not shown) described above, the electrode pad 79 is configured by a single layer film made of a single metal formed by, for example, vapor deposition or sputtering, or a stacked film in which different metals are stacked. The electrode pad 79 and the external electrode are electrically connected to each other via a wiring (not shown).

  The third substrate 76 is integrally coupled to the end surface on the + side in the Y′-axis direction of the second substrate 75 by sintering or the like. The third substrate 76 is formed in a rectangular frame shape having a size equivalent to the frame portion 77 of the second substrate 75 in a plan view as viewed from the Y′-axis direction.

The outer surfaces of the first substrate 74, the second substrate 75, and the third substrate 76 are formed flush with each other.
The frame portion 77 of the second substrate 75 and the inner surface of the third substrate 76 are formed flush with each other. The inner surfaces of the second substrate 75 and the third substrate 76 constitute an inner surface 71 b of the recess 71.

  The sealing plate 73 is formed in a rectangular plate shape having the same size as the mounting substrate 72 in plan view. The sealing plate 73 is bonded to the opening edge of the mounting substrate 72 (the end surface on the Y′-axis direction side of the third substrate 76) by, for example, seam welding with a seal ring (not shown) interposed therebetween, and the recess 71 is hermetically sealed. It has stopped. The space defined by the mounting substrate 72 and the sealing plate 73 constitutes a hermetically sealed cavity C.

  As shown in FIGS. 2 and 3, the piezoelectric vibrating piece 10 is mounted on each mounting portion 78 via the mounting member 8. The mounting member 8 is a conductive adhesive or the like, and for example, a silver paste or the like is suitable. The piezoelectric vibrating reed 10 is placed so that the mounting member 8 disposed in each mounting portion 78 and the projecting portions 31 and 32 overlap each other.

The mounting member 8 disposed in the first mounting portion 78A includes a main surface 28c of the outer peripheral portion 28 of the piezoelectric plate 11, a side surface 28d of the outer peripheral portion 28, a main surface 31a of the first projecting portion 31, and a first surface. Attached across the side surface 31b of the protruding portion 31.
The main surface 28c of the outer peripheral portion 28 is a main surface on the Y′-axis direction − side. The side surface 28 d of the outer peripheral portion 28 is a side surface facing the Z′-axis direction + side of the outer peripheral portion 28. The main surface 31 a of the first protrusion 31 is a main surface on the Y′-axis direction − side of the first protrusion 31. The side surface 31 b of the first protrusion 31 is a side surface facing the Z′-axis direction + side of the first protrusion 31.
In other words, the mounting member 8 disposed in the first mounting portion 78 </ b> A is provided on the end portion 11 b on the Z′-axis direction + side on the base end 11 a side of the piezoelectric plate 11.

The mounting member 8 disposed in the second mounting portion 78B includes a main surface 28c, a side surface 28e of the outer peripheral portion 28, a main surface 32a of the second projecting portion 32, and a second projecting portion of the outer peripheral portion 28 of the piezoelectric plate 11. Attached across the side surface 32b of the part 32. The main surface 28c of the outer peripheral portion 28 is a main surface on the Y′-axis direction − side. The side surface 28e of the outer peripheral portion 28 is a side surface facing the Z′-axis direction − side. The main surface 32a of the second protrusion 32 is a main surface on the Y′-axis direction − side. The side surface 32b of the second protrusion 32 is a side surface facing the Z′-axis direction − side.
In other words, the mounting member 8 disposed in the second mounting portion 78 </ b> B is provided at the end portion 11 c on the Z′-axis direction − side on the base end 11 a side of the piezoelectric plate 11.
That is, the base end 11a side of the piezoelectric plate 11 is mounted by the mounting member 8 via the first mounting portion 78A and the second mounting portion 78B.

  As described above, the mounting member 8 disposed in the first mounting portion 78A is attached to the side surface 28d of the outer peripheral portion 28, the main surface 31a of the first projecting portion 31, and the side surface 31b of the first projecting portion 31. . The mounting member 8 disposed in the second mounting portion 78B is attached to the side surface 28e of the outer peripheral portion 28, the main surface 32a of the second projecting portion 32, and the side surface 32b of the second projecting portion 32. Therefore, it can suppress that each mounting member 8 adheres to the back surface mesa part 24, and an unnecessary vibration is induced, and can increase the adhesion area of each mounting member 8. FIG. Thereby, it is possible to obtain excellent vibration characteristics while improving the mounting strength of the piezoelectric vibrating piece 10.

  Each mounting member 8 is provided on the base end 11 a side of the piezoelectric plate 11. Each mounting member 8 is disposed at a position separated from the back surface mesa portion 24. Each mounting member 8 adheres to the outer surface of each protrusion 31, 32, thereby electrically connecting each mount electrode 63, 64 on the outer surface of each protrusion 31, 32 and the electrode pad 79 of the package 70. Yes.

Here, the inclined surface 26 of the surface mesa portion 23 is formed along the inner peripheral edge 28 a of the main surface on the Y′-axis direction + side in the outer peripheral portion 28. The inclined surface 26 of the surface mesa portion 23 is inclined in the Y′-axis direction + side from the inner peripheral edge 28 a of the outer peripheral portion 28 (that is, the outer peripheral edge 23 a of the surface mesa portion 23) toward the top surface 25 of the surface mesa portion 23. ing.
In addition, an inclined surface 26 of the back surface mesa portion 24 is formed along the inner peripheral edge 28 b of the main surface on the Y′-axis direction − side in the outer peripheral portion 28. The inclined surface 26 of the back surface mesa portion 24 is inclined in the Y′-axis direction − side from the inner peripheral edge 28 b of the outer peripheral portion 28 (that is, the outer peripheral edge 24 a of the back surface mesa portion 24) toward the top surface 25 of the back surface mesa portion 24. ing.

That is, each mesa portion 23, 24 has an inclined surface 26 that is formed along the inner peripheral edge of the outer peripheral portion 28 and is inclined from the inner peripheral edge toward the top surface 25 (that is, the center of the piezoelectric vibrating piece 10). .
Therefore, the inclined surface 26 of the front surface mesa portion 23 and the inclined surface 26 of the back surface mesa portion 24 are arranged at positions away from the first protruding portion 82A and the second protruding portion 82B. Thereby, it can suppress that the 1st overhang | projection part 82A and the 2nd overhang | projection part 82B contact each inclined surface 26, and can obtain the outstanding vibration characteristic.

  In addition, since the vibration unit 20 is formed in a rectangular plate shape whose longitudinal direction is the Z′-axis direction, a low CI value can be maintained even when the piezoelectric vibrating piece 10 is downsized. That is, the AT-cut quartz crystal substrate is composed of an X axis and a Z ′ axis. Under such a configuration, when the AT-cut quartz substrate is undergoing thickness shear vibration, electric polarization occurs in the X axis and the Z ′ axis. Electric polarization is a charge bias, which is sinusoidal on the X axis and linear on the Z ′ axis. By setting the Z ′ axis in which the electric polarization is linear to the longitudinal direction, the side where the strongest charge is generated can be lengthened. The CI value becomes lower as the region where the strong charge is generated becomes wider. Therefore, a lower CI value can be maintained by setting the Z ′ axis in the longitudinal direction, and more excellent vibration characteristics can be obtained.

Further, an inclined surface 26 of the surface mesa portion 23 is formed between the top surface 25 of the surface mesa portion 23 and the surface of the protruding portions 31 and 32 that faces the top surface 25. Therefore, compared to the case where a step of 90 ° is formed between the top surface 25 and the surface of the protrusions 31 and 32 facing the top surface 25, the top surface 25 and the top of the protrusions 31 and 32 are the same. The surface facing the surface 25 can be gently connected. Similarly, it is possible to gently connect the top surface 25 of the back surface mesa portion 24 and the surface of the protruding portions 31 and 32 facing the top surface 25.
Therefore, it is possible to suppress unnecessary vibrations from being induced at the boundary portion between the top surface 25 and the inclined surface 26 of the surface mesa portion 23. Similarly, unnecessary vibration can be suppressed from being induced at the boundary between the top surface 25 and the inclined surface 26 of the back surface mesa portion 24. Thereby, CI value can be reduced and a vibration characteristic can be improved.

The pair of projecting portions 31 and 32 are projected from the vibrating portion 11 in a direction perpendicular to the thickness direction, and the pair of projecting portions 31 and 32 are attached to the mounting member 8. Thereby, the mounting member 8 can be separated from the vibration part 11, and the outstanding vibration characteristic can be acquired.
Also, the thickness shear vibration, which is the main vibration mode of the AT-cut quartz substrate, is a vibration that is greatly displaced in the X-axis direction. According to the present embodiment, the pair of protrusions 31 and 32 are arranged along the Z′-axis direction orthogonal to the X-axis direction where the displacement of the vibration unit 20 is large. For this reason, the protrusions 31 and 32 fixed to the package 70 via the mounting member 8 do not hinder the displacement of the vibration unit 20 in the X-axis direction. Therefore, it is possible to suppress occurrence of unnecessary vibration in the protrusions 31 and 32. Thereby, the vibration part 20 can obtain a more excellent vibration characteristic.

A first overhanging portion 82A and a second overhanging portion 82B are provided on the outer peripheral side of the front surface mesa portion 23 and the back surface mesa portion 24. The first overhanging portion 82A protrudes from the tip end of the piezoelectric plate 11 (that is, the other end of the piezoelectric plate 11) 11d in the side surface 28d in the Z′-axis direction + side. The tip 11d of the piezoelectric plate 11 is located on the opposite side of the base end 11a of the piezoelectric plate 11 in the X-axis direction.
Further, the first projecting portion 82 </ b> A has an end surface 82 a opposite to the base end 11 a formed on the same plane as the distal end surface of the distal end 11 d of the piezoelectric plate 11. Note that the end surface 82a of the first overhang portion 82A can be protruded from the tip 11d of the piezoelectric plate 11 to the X axis direction-side.
Further, the end surface 82 b on the base end 11 a side of the first overhanging portion 82 </ b> A is provided on the front end 11 d side of the piezoelectric plate 11 from the top surface 25.
Further, the first overhang portion 82A is formed in a rectangular shape in plan view, and is formed to have the same thickness as the outer peripheral portion 28 of the vibration portion 20.

The second projecting portion 82B projects from the tip 11d of the piezoelectric plate 11 to the Z′-axis direction − side of the side surface 28e. Similarly to the first overhanging portion 82A, the second overhanging portion 82B has an end surface 82c opposite to the base end 11a formed on the same surface as the front end surface of the front end 11d of the piezoelectric plate 11. Note that the end surface 82c of the second overhang portion 82B can be protruded from the tip 11d of the piezoelectric plate 11 to the X-axis direction minus side.
Further, the end surface 82d on the base end 11a side of the second overhanging portion 82B is provided on the tip end 11d side of the piezoelectric plate 11 from the top surface 25. The second overhang portion 82B is formed in a rectangular shape in plan view, and has the same thickness as that of the outer peripheral portion 28 of the vibration portion 20.

  According to the first embodiment, the end surface 82b of the first overhang portion 82A is provided on the tip 11d side of the piezoelectric plate 11 from the top surface 25. Further, the end surface 82d of the second overhang portion 82B is provided on the tip 11d side of the piezoelectric plate 11 from the top surface 25. Thereby, the overhang part 82 can be separated from the top surface 25 in the X-axis direction, and propagation of vibration to the overhang part 82 can be suppressed.

  In addition, the mesa portions 23 and 24 of the piezoelectric plate 11 bulge in the thickness direction of the piezoelectric plate 11. Therefore, the outer peripheral portion 28 is smaller in thickness than the mesa portions 23 and 24. Therefore, by forming the first overhanging portion 82A and the second overhanging portion 82B to have the same thickness as the outer peripheral portion 28 of the vibration unit 20, the overhanging portion 82 can be reduced in weight. Thereby, propagation of vibration to the overhang portion 82 can be suppressed.

Furthermore, the first overhanging portion 82A is disposed so as to overlap a part of the first protruding portion 86A. Similarly, the 2nd overhang | projection part 82B is arrange | positioned so that it may overlap with a part of 2nd projection part 86B. By arranging the protruding portion 82 so as to overlap a part of the protruding portion 86, the protruding portion 82 contacts the protruding portion 86 at a position away from the vibrating portion 20 when the piezoelectric vibrator 1 receives an impact. Can be made. Thereby, it is possible to prevent the vibration characteristics of the piezoelectric vibrating piece 10 from being affected when the projecting portion 82 contacts the protrusion 86.
By projecting the overhanging portion 82 from the vibrating portion 20 of the piezoelectric vibrating piece 10, in particular, in the small piezoelectric vibrating piece 10, the overhanging portion 82 can be brought into contact with the protrusion 86 at a position away from the vibrating portion 20. It becomes possible. Thereby, even the small piezoelectric vibrating piece 10 can be prevented from affecting the vibration characteristics of the piezoelectric vibrating piece 10.

  Further, the base end 11 a side of the piezoelectric vibrating piece 10 is mounted by the mounting member 8, and the overhang portion 82 is provided on the tip 11 d side of the piezoelectric vibrating piece 10. Therefore, when the piezoelectric vibrating piece 10 receives an impact, the displacement of the piezoelectric vibrating piece 10 on the tip 11d side can be suppressed. Thereby, the displacement of the piezoelectric vibrating piece 10 can be efficiently suppressed, and the vibration characteristics of the piezoelectric vibrating piece 10 can be prevented from being affected.

  Next, the piezoelectric vibrating reeds 100 to 150 according to the second to seventh embodiments will be described with reference to FIGS. Note that the same reference numerals in the second to seventh embodiments denote the same components as those in the first embodiment, and a detailed description thereof will be omitted.

(Second Embodiment)
FIG. 4 is a plan view showing the piezoelectric vibrating piece 100 according to the second embodiment.
As shown in FIG. 4, the piezoelectric vibrating piece 100 is the same as the piezoelectric vibrating piece 10 of the first embodiment except that the protruding portion 102 is different from the protruding portion 82 of the first embodiment.
The overhang portion 102 includes a first overhang portion 102A and a second overhang portion 102B. The first projecting portion 102A projects from the distal end surface 11e toward the X axis direction minus side at the distal end 11d of the piezoelectric plate 11, and projects from the side surface 28d of the outer peripheral portion 28 toward the Z ′ axis direction plus side. .
The second projecting portion 102B projects from the distal end surface 11e to the X axis direction − side at the distal end 11d of the piezoelectric plate 11 and projects from the side surface 28e of the outer peripheral portion 28 to the Z ′ axis direction − side. .
According to the piezoelectric vibrating piece 100 according to the second embodiment, the same operational effects as those of the piezoelectric vibrating piece 10 according to the first embodiment can be achieved.

(Third embodiment)
FIG. 5 is a plan view showing the piezoelectric vibrating piece 110 according to the third embodiment.
As shown in FIG. 5, the piezoelectric vibrating piece 110 is the same as the piezoelectric vibrating piece 10 of the first embodiment except that the protruding portion 112 is different from the protruding portion 82 of the first embodiment.
The overhang portion 112 includes a first overhang portion 112A and a second overhang portion 112B. 112 A of 1st overhang | projection parts are formed in the end surface 112a by the side of the base end 11a of the piezoelectric plate 11 in the shape of an inclination. The end surface 112a is inclined in the X-axis direction minus side as it is away from the side surface 28d of the outer peripheral portion 28.
Other shapes of the first projecting portion 112A are the same as those of the first projecting portion 82A of the first embodiment.

In the second overhanging portion 112B, the end surface 112b on the base end 11a side of the piezoelectric plate 11 is formed in an inclined shape. The end surface 112b is inclined in the X-axis direction minus side as it is away from the side surface 28e of the outer peripheral portion 28.
Other shapes of the second overhang portion 112B are the same as those of the second overhang portion 82B of the first embodiment.
That is, the overhanging portion 112 is gradually tapered toward the direction away from the mesa portions 23 and 24 in plan view. Thereby, the overhang | projection part 112 can be made lightweight and the propagation of the vibration to the overhang | projection part 112 can be suppressed.

(Fourth embodiment)
FIG. 6 is a plan view showing the piezoelectric vibrating piece 120 according to the fourth embodiment.
As shown in FIG. 6, the piezoelectric vibrating piece 120 is the same as the piezoelectric vibrating piece 10 of the first embodiment except that the protruding portion 122 is different from the protruding portion 82 of the first embodiment.
The overhang portion 122 includes a first overhang portion 122A and a second overhang portion 122B. The first overhanging portion 122A is inclined in the Z′-axis direction + side and in the X-axis direction − side in plan view. The second overhang portion 122B is inclined toward the Z′-axis direction-side and toward the X-axis direction-side in plan view.
The overhanging part 122 is gradually tapered toward the direction away from the mesa parts 23 and 24 in plan view. Thereby, the overhang | projection part 122 can be made lightweight and the propagation of the vibration to the overhang | projection part 122 can be suppressed.

(Fifth embodiment)
FIG. 7 is a side view showing the piezoelectric vibrating piece 130 according to the fifth embodiment.
As shown in FIG. 7, the piezoelectric vibrating piece 130 is the same as the piezoelectric vibrating piece 10 of the first embodiment except that the protruding portion 132 is different from the protruding portion 82 of the first embodiment.
The overhang portion 132 includes a first overhang portion 132A and a second overhang portion 132B. The first overhang portion 132A is formed to have a thickness dimension T1 larger than that of the outer peripheral portion 28. Other shapes of the first overhang portion 132A are the same as those of the first overhang portion 82A of the first embodiment.
The second overhang 132B is formed with a thickness dimension T1 larger than that of the outer peripheral portion 28. Other shapes of the second projecting portion 132B are the same as those of the second projecting portion 82B of the first embodiment.
By forming the thickness dimension T1 of the overhanging portion 132 to be larger than that of the outer peripheral portion 28, the height dimension H1 of the protrusion 86 can be kept small. Therefore, the protrusion 86 can be provided in the vicinity of the inner surface 71 b of the recess 71. Thereby, the overhang | projection part 132 can be further separated from the vibration part 20, and propagation of the vibration to the overhang | projection part 132 can be suppressed.

(Sixth embodiment)
FIG. 8 is a plan view showing a piezoelectric vibrating piece 140 according to the sixth embodiment.
As shown in FIG. 8, the piezoelectric vibrating piece 140 is formed by forming a piezoelectric plate 142 into a rectangular plate shape whose longitudinal direction is the X-axis direction, and other members are the same as those of the piezoelectric vibrating piece 10 of the first embodiment. is there.
The piezoelectric vibrating piece 140 includes a pair of projecting portions 145 and 146 arranged along the Z′-axis direction, and an overhanging portion 147 arranged along the Z′-axis direction (the first overhanging portion 147A and the second overhanging portion). A protruding portion 147B). By arranging the first projecting portion 145 and the second projecting portion 146 along the Z′-axis direction, excellent vibration characteristics can be obtained in the same manner as the piezoelectric vibrating piece 10 of the first embodiment.

(Seventh embodiment)
FIG. 9 is a plan view showing a piezoelectric vibrating piece 150 according to the seventh embodiment.
As shown in FIG. 9, the piezoelectric vibrating piece 150 is the same as the piezoelectric vibrating piece 10 of the first embodiment except that the piezoelectric plate 151 is different from the piezoelectric plate 11 of the first embodiment.
The piezoelectric plate 151 includes mesa portions 152 and 153 and an outer peripheral portion 28. The front surface mesa portion 152 and the back surface mesa portion 153 are surrounded by surfaces 154 and 155 that are orthogonal to the top surface 25 in the Y′-axis direction. The surfaces 154 and 155 that are orthogonal to the top surface 25 are connected to the inner peripheral edge of the outer peripheral portion 28 at the opposite edge of the top surface 25.
Further, each projecting portion 156 has an end surface 156 a on the tip 151 a side of the piezoelectric plate 11 provided on the tip 151 a side of the piezoelectric plate 151 from the mesa portions 152 and 153.
Thereby, each overhang | projection part 156 can be separated from the mesa parts 152 and 153 in the X-axis direction, and the propagation of vibration to the overhang part 82 can be suppressed.

The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
For example, in the first to seventh embodiments, the protruding portions 82, 102, 112, 122, 132, 147, 156 of the piezoelectric vibrating reeds 10, 100, 110, 120, 130, 140, 150 are protrusions. Although the example which overlaps a part of 86 was demonstrated, it does not limit to this. As another example, it is also possible to arrange the overhanging portion so that the entire region of the protruding portion 86 overlaps.

Moreover, although the said 1st Embodiment-7th Embodiment demonstrated the example which formed the overhang | projection part 82,102,112,122,132,147,156 with a fixed thickness dimension, it is limited to this. is not. As another example, it is possible to reduce the thickness dimension of the overhanging portion away from the outer peripheral portion. That is, it is possible to form the overhanging portion in a tapered shape in the thickness direction (Y′-axis direction).
Thereby, the overhanging portion can be reduced in weight, and the propagation of vibration to the overhanging portion can be suppressed.

  Further, in the first to seventh embodiments, the example in which the protrusion 86 is formed in a cylindrical shape has been described. However, the present invention is not limited to this, and the protrusion 86 is formed in another shape such as a rectangular body. Is also possible.

  Moreover, although the said 1st Embodiment-7th Embodiment demonstrated the example which provided the pair of protrusion parts 31 and 32 in the vibration part 20, and mounted the pair of protrusion parts 31 and 32 in the mounting part 78, this. It is not limited. As another example, the vibration part 20 can be mounted on the mounting part 78.

DESCRIPTION OF SYMBOLS 1 ......... Piezoelectric vibrator 8 ......... Mounting member 10,100,110,120,130,140,150 ... piezoelectric vibration piece 11 ... piezoelectric plate 11a ... base end (other end) of piezoelectric plate
11d: tip of piezoelectric plate (one end)
20 …… Vibration part 23,152 …… Surface mesa part (mesa part)
24,153 …… Back side mesa part (mesa part)
25 …… Top surface 26 …… Inclined surface 28 …… Outer peripheral portion 31, 32, 145, 146 ... First and second protrusions 70 …… Package 82, 102, 112, 122, 132, 147, 156 ... Tension Protruding part 82b ... End face on the base end side T1 ... Thickness dimension of the overhanging part

Claims (8)

A piezoelectric vibrating piece formed of an AT-cut quartz substrate;
The piezoelectric vibration piece is mounted via a mounting member, and includes a package having a protrusion protruding toward the piezoelectric vibration piece,
The piezoelectric vibrating piece is
Mounted at one end in a direction perpendicular to the thickness direction of the piezoelectric vibrating piece,
A mesa portion that bulges in the thickness direction;
An overhang part provided on the outer peripheral side of the mesa part,
The overhanging portion is
Provided on the other end side opposite to the one end of the piezoelectric vibrating piece, and disposed so as to overlap at least a part of the protrusion in the thickness direction,
A piezoelectric vibrator characterized by that. The overhanging portion is
In a plan view seen from the thickness direction, formed gradually tapered toward the direction away from the mesa portion,
The piezoelectric vibrator according to claim 1. The piezoelectric vibrating piece is
An outer peripheral portion surrounding the periphery of the mesa portion;
The overhanging portion is
Formed in the same thickness as the outer periphery,
The piezoelectric vibrator according to claim 1, wherein the piezoelectric vibrator is characterized in that The piezoelectric vibrating piece is
An outer peripheral portion surrounding the periphery of the mesa portion;
The overhanging portion is
The thickness dimension was formed larger than the outer periphery,
The piezoelectric vibrator according to claim 1, wherein the piezoelectric vibrator is characterized in that The mesa part is
Having an inclined surface inclined from the outer peripheral edge of the mesa portion toward the center of the piezoelectric vibrating piece;
The piezoelectric vibrator according to claim 1, wherein the piezoelectric vibrator is provided. The mesa part is
A top surface surrounded by the inclined surface;
The overhanging portion is
The end surface on the one end side is provided on the other end side of the piezoelectric vibrating piece from the top surface,
The piezoelectric vibrator according to claim 5. The piezoelectric vibrating piece is
Comprising a vibrating portion having an outer peripheral portion formed around the mesa portion;
The vibrating portion is formed in a rectangular plate shape having the longitudinal direction in the Z′-axis direction of the AT-cut quartz crystal substrate,
The piezoelectric vibrator according to claim 1, wherein the piezoelectric vibrator is provided. The piezoelectric vibrating piece is
Comprising a vibrating portion having an outer peripheral portion formed around the mesa portion;
A protruding portion protruding from the vibrating portion in a direction orthogonal to the thickness direction,
The protrusion is attached to the mounting member;
The piezoelectric vibrator according to claim 1, wherein the piezoelectric vibrator is provided.

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