JP2006050186A - Piezoelectric vibrating piece and piezoelectric device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric vibrating piece capable of effectively preventing vibration leakage by controlling vibration transmitted to a base and realizing stable vibration characteristics, and a piezoelectric device using the piezoelectric vibrating piece.
A piezoelectric vibrating piece 32 comprising a pair of vibrating arms 34 and 35, and a base 51 having fixed regions 52a and 52b to which the pair of vibrating arms are connected and joined to a package, The pair of vibrating arms 34 and 35 have long grooves 36 and 37 extending along the longitudinal direction, respectively, and the base 51 extends to the vicinity of the center O1 of the long grooves 36 and 37 of the pair of vibrating arms 34 and 35 in the width direction. Extending portions 36a and 37a formed by extending one long groove 36 of the pair of vibrating arms and the other long groove 37 of the pair of vibrating arms extending. The formed extending portion 37a is substantially symmetric about a virtual line Y1 in the longitudinal direction passing through the vicinity of the center O1.
[Selection] Figure 3

Description

  The present invention relates to a piezoelectric vibrating piece having a vibrating arm and a piezoelectric device using the same.

Piezoelectric devices are widely used in small information devices such as HDDs (hard disk drives), mobile computers, and IC cards, and mobile communication devices such as mobile phones, car phones, and paging systems.
FIG. 8 is a schematic perspective view of the piezoelectric vibrating piece 1 used in this piezoelectric device, and FIG. 9 is a schematic cross-sectional view taken along line AA of FIG.
Here, the piezoelectric vibrating piece 1 is formed of quartz and is a so-called tuning fork type piezoelectric vibrating piece having a pair of vibrating arms 2 and 3 and a base portion 4.

  That is, the base portion 4 has fixing regions 5 and 5 (parts indicated by parallel oblique lines in FIG. 8) that are bonded and fixed to the package and an adhesive in the vicinity of the end portion, and is opposite to the fixing regions 5 and 5. In addition, the pair of vibrating arms 2 and 3 are integrally connected to support the vibrating arms 2 and 3.

  The resonating arms 2 and 3 have a width that is smaller than the width of the base portion 4 and extends from the base portion 4 so as to be parallel to each other. Each of the pair of vibrating arms 2 and 3 is formed with long grooves 6 and 6 extending along the longitudinal direction. As shown in FIG. 9, the long grooves 6 and 6 are provided on the front and back of the vibrating arms 2 and 3, and thin portions 7 and 7 are formed in the vibrating arms 2 and 3 along the longitudinal direction, respectively. It is supposed to be. An electric field is efficiently generated in the thin portions 7 and 7 so that a predetermined vibration frequency can be obtained even if the vibrating arms 2 and 3 are downsized (for example, patents). Reference 1).

JP 2002-261575 A

However, the vibrating arms 2 and 3 are connected to the base 4 that is wider than the vibrating arms 2 and 3, and when the vibrations of the vibrating arms 2 and 3 are transmitted to the base 4, the vibration energy is dispersed. The value is small, which causes a state in which vibration is not stable.
Further, the vibrating arms 2 and 3 have a complicated shape, such as when the outer shape and the long grooves 6 and 6 are formed by wet etching, for example, the protrusion 8 is generated as shown in FIG. The shapes of the vibrating arm 2 and the vibrating arm 3 are not symmetrical. Then, the vibration states of the vibrating arm 2 and the vibrating arm 3 are different, and the vibration transmitted from the vibrating arm 2 to the base 4 and the vibration transmitted from the vibrating arm 3 to the base 4 are not the center O in the width direction of the base 4, You will meet at a position shifted from the center O. For this reason, the vibration of the base 4 becomes unstable such that the left and right balance in FIG.

  It is an object of the present invention to provide a piezoelectric vibrating piece that can control vibration transmitted to a base, effectively prevent vibration leakage, and realize stable vibration characteristics, and a piezoelectric device using the piezoelectric vibrating piece. .

  According to the first aspect of the present invention, there is provided a piezoelectric vibrating piece including a pair of vibrating arms and a base having a fixed region to which the pair of vibrating arms are connected and joined to a package. The pair of vibrating arms each have a long groove extending along the longitudinal direction, and the base has an extending portion formed by extending each long groove of the pair of vibrating arms to the vicinity of the center in the width direction. And an elongated portion formed by extending one long groove of the pair of vibrating arms, and an elongated portion formed by extending the other long groove of the pair of vibrating arms, a longitudinal direction passing through the vicinity of the center. This is achieved by a piezoelectric vibrating piece that is substantially symmetrical about a virtual line of direction.

According to the configuration of the first invention, the base portion has the extending portion formed by extending the long grooves of the pair of vibrating arms. For this reason, when the vibration of the pair of vibrating arms is transmitted to the base portion, the vibration is concentrated on a fragile extending portion formed by extending the long groove. Therefore, the Q value can be increased by preventing the vibration of the vibrating arm from being dispersed when transmitted to the base.
Further, the extending portion is extended to near the center in the width direction, and is formed by extending one long groove of the pair of vibrating arms and the other long groove of the pair of vibrating arms. The stretched portion is substantially symmetric about a virtual line in the longitudinal direction passing through the vicinity of the center. For this reason, the vibration transmitted from one vibrating arm to the base and the vibration transmitted from the other vibrating arm to the base are transmitted along the symmetrical extension part to the vicinity of the center in the width direction of the base, and meet near the center. . Therefore, the vibration transmitted to the base is transmitted in a balanced manner on both sides centering on the vicinity of the center in the width direction, and can be made stable vibration such as effectively preventing the twist of the base, thereby preventing vibration leakage. .
Thus, as an effect of the present invention, it is possible to provide a piezoelectric vibrating piece that can control vibration transmitted to the base, effectively prevent vibration leakage, and realize stable vibration characteristics.

According to a second invention, in the configuration of the first invention, the extending portion is formed in a region opposite to the fixed region.
According to the structure of 2nd invention, the extending | stretching part is formed in the area | region on the opposite side to a fixed area | region. Therefore, the vibration of the vibrating arm is transmitted to the extending portion located at a position away from the fixing region of the base portion, thereby further preventing vibration leakage.

According to a third aspect of the present invention, in the configuration according to the first or second aspect, the extending portion is formed along the outer edge so as to have a substantially shortest distance to the vicinity of the center in the width direction of the base portion. It is characterized by.
According to the configuration of the third invention, since the extending portion is formed along the outer edge so as to be approximately the shortest distance to the vicinity of the center in the width direction of the base portion, it transmits vibration to an extra portion of the base portion. To prevent. Therefore, as compared with the first or second invention, it is possible to further prevent the vibration from being dispersed at the base portion to increase the Q value and prevent vibration leakage.

According to a fourth invention, in any one of the first to third inventions, an excitation electrode for vibrating the vibrating arm is not formed in the extending portion.
According to the configuration of the fourth aspect of the invention, since the excitation electrode is not formed in the extending portion, it is possible to prevent a situation in which the base portion where the extending portion is formed vibrates positively and is distorted.

According to a fifth invention, in any one of the first to fourth inventions, the base portion has a notch portion between the fixed region and the extending portion.
According to the structure of 5th invention, a base has a notch between a fixed area | region and an extending | stretching part. Therefore, it is difficult for the vibration of the vibrating arm to be transmitted to the fixed region, and vibration leakage can be prevented more than in the first to fourth inventions.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the long groove is formed to the tip of the vibrating arm.
According to the configuration of the sixth invention, the long groove is formed up to the tip of the vibrating arm. For this reason, the vibrating arm has the same structure from the base to the tip, and the entire vibrating arm performs a stable bending vibration. Therefore, stable vibration is transmitted to the extending portion extending to the base, and vibration leakage can be more effectively prevented as compared with the first to fifth inventions.

According to a seventh invention, in any one of the first to sixth inventions, the resonating arm is provided in the long groove so as to cross in the width direction and separated in the width direction by the long groove. A support portion for integrally connecting the materials is formed.
According to the structure of 7th invention, the support part which connects in the long groove so that the material which comprises the vibration arm provided so that it might cross in the width direction and was separated in the width direction by the long groove may be formed integrally is formed. . As a result, the support portion supports the material constituting the vibrating arm separated in the width direction by the long groove, so that the vibrating arm can reinforce the rigidity in the torsional direction and can stably vibrate. Therefore, stable vibration is transmitted to the extended portion extended to the base, and vibration leakage can be more effectively prevented as compared with the first to sixth inventions.

  According to an eighth aspect of the present invention, there is provided a piezoelectric vibrating piece having a package and a base provided with a fixing region bonded to the package, and having a pair of vibrating arms extending in parallel from the base. Each of the pair of vibrating arms has a long groove extending along a longitudinal direction, and the base has each long groove of the pair of vibrating arms extending to the vicinity of the center in the width direction. An extending portion formed by extending one long groove of the pair of vibrating arms, and an extending portion formed by extending the other long groove of the pair of vibrating arms. Is achieved by a piezoelectric device that is substantially symmetric about a longitudinal imaginary line passing through the vicinity of the center.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.
Note that the embodiments described below are preferred specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise stated, the present invention is not limited to these forms.

1 is a schematic plan view of, for example, a piezoelectric vibrator 30 which is a piezoelectric device according to an embodiment of the present invention, FIG. 2 is a schematic cross-sectional view taken along line BB of FIG. 1, and FIG. FIG. 4 is a cross-sectional view taken along the line CC of FIG. 3. For convenience of drawing, the excitation electrode is not shown in FIGS. 1 and 2.
In these drawings, the piezoelectric vibrator 30 accommodates a piezoelectric vibrating piece 32 in a package 28.

The package 28 is formed by, for example, laminating a plurality of substrates formed by molding a ceramic green sheet made of aluminum oxide as an insulating material, and then sintering the package. An internal space S1 is formed.
Further, a lid 39 is bonded to the open end surface at the open upper end of the package 28 via a bonding material 38 such as low melting point glass, for example, so that the package 28 is sealed.

  In addition, in the vicinity of the left end portion of the package 28 in FIGS. 1 and 2, electrode portions 31a and 31b having Au or Ni plating applied to both ends in the width direction are exposed at a predetermined interval so as to be exposed to the internal space S1. Is formed. The electrode portions 31a and 31b are routed through the package 28 and connected to the mounting terminal portions 33 and 33, and are supplied with a driving voltage having different polarities.

On the electrode portions 31a and 31b, for example, conductive adhesives 43 and 43, which are adhesives, are applied. As the conductive adhesives 43, 43, epoxy-based, polyimide-based, or silicone-based conductive materials in which conductive particles such as silver fine particles are contained in a synthetic resin agent as an adhesive component that exhibits bonding strength. An adhesive or the like can be used.
The piezoelectric vibrating piece 32 is placed on the conductive adhesives 43 and 43. That is, as will be described later, the piezoelectric vibrating piece 32 is provided with lead electrodes 52a and 52b at the ends of the base 51 opposite to the vibrating arms 34 and 35 and near both ends in the width direction of the base 51. The extraction electrodes 52 a and 52 b are placed so as to face the conductive adhesives 43 and 43.
In this way, the piezoelectric vibrating piece 32 is cantilevered and fixed to the package 28 via the conductive adhesives 43 and 43, and the electrode portions 31 a and 31 b provided on the package 28 are connected to the piezoelectric vibrating piece 32. A driving voltage is supplied to the power source.

The piezoelectric vibrating piece 32 is formed of, for example, quartz, and a piezoelectric material such as lithium tantalate or lithium niobate can be used in addition to quartz. In the case of the present embodiment, the piezoelectric vibrating piece 32 has a particularly illustrated shape in order to form a small size and obtain necessary performance.
That is, the piezoelectric vibrating piece 32 includes a base portion 51 and a pair of vibrating arms 34 and 35 extending in parallel from the base portion 51 toward the right side in FIG. A so-called tuning fork type piezoelectric vibrating piece having a simple shape is used.

  As shown in FIG. 3, the pair of vibrating arms 34 and 35 have long grooves 36 and 37 extending along the longitudinal direction, respectively. As shown in FIG. 4, the long grooves 36 and 37 are formed on the front and back surfaces (upper and lower surfaces in FIG. 4) of the vibrating arms 34 and 35, and the end surfaces in the width direction of the vibrating arms 34 and 35 are substantially H-shaped. ing. Excitation electrodes 46 and 46 are provided on the inner surfaces of the long grooves 36 and 36 on the vibrating arm 34 side, and excitation electrodes 47 and 47 are provided on the inner surfaces of the long grooves 37 and 37 on the vibrating arm 35 side. . The excitation electrodes 46 and 47 are electrodes arranged so as to face each other with different polarities, and are electrodes for actively vibrating the vibrating arms 34 and 35.

  That is, as shown in FIG. 3, the excitation electrode 47 in the long groove 37 is drawn out to the surface of the base 51 and is connected to the lead electrode 52a through the vicinity of the center O1 in the width direction of the base 51. 52 a is connected to an excitation electrode 47 provided on the side surface of the vibrating arm 34. The excitation electrode 46 in the long groove 36 passes through the vicinity of the crotch M, which is the free end side of the base 51 that connects the vibration arm 34 and the vibration arm 35, and the excitation electrode 46 provided on the side surface of the vibration arm 35. The excitation electrode 46 is pulled out to the right side surface of the base 51 in FIG. 3 and connected to the extraction electrode 52b.

  In this way, as shown in FIGS. 3 and 4, the electric field is efficiently generated in the portions 34a, 34b, 35a, 35b in which the widths of the vibrating arms 34, 35 separated in the width direction by the long grooves 36, 37 are reduced. It can be generated well and the CI value (cristal impedance value) of the piezoelectric vibrating piece 32 can be kept low. Accordingly, the CI value of the piezoelectric vibrating piece 32 is formed to be the CI value of the conventional piezoelectric vibrating piece, and the lengths of the vibrating arms 34 and 35 can be shortened.

  The base 51 is a part having a fixed region where the pair of vibrating arms 34 and 35 are integrally connected and joined to the package 28. That is, the base 51 is a portion having two functions of connecting the elongated rectangular vibrating arm 34 and the vibrating arm 35 and a function fixed to the package 28, and is an imaginary line in the short direction passing through the crotch M. It is on the fixed region side (lower side in FIG. 3) from X1. In the present embodiment, since the portions of the extraction electrodes 52a and 52b are joined to the package 28 as described above, the region where the extraction electrodes 52a and 52b are provided becomes the fixed region.

Here, the base 51 has extended portions 36a and 37a formed by extending the long grooves 36 and 37 provided in the pair of vibrating arms 34 and 35 to the base 51 as shown in FIG. Yes. Since the extending portions 36 a and 37 a have a groove shape, the extending portions 36 a and 37 a are weaker than other portions of the base 51, and concentrate the vibration transmitted to the base 51.
The extending portions 36a and 37a are also formed on the back surface in FIG. 3. However, the extending portions on the back surface have the same configuration as the extending portions 36a and 37a on the front surface. Only will be described.

The extending portions 36a and 37a are formed integrally with, for example, wet etching at the same time as forming the long grooves 36 and 37 on the vibrating arm side, and in this embodiment, in the vicinity of the boundary between the vibrating portion 34 and 35 of the base 51, It is not a width larger than the width of the long grooves 36 and 37, but is formed from a bottomed groove having the same depth as the long grooves 36 and 37.
The extending portions 36a and 37a are each formed up to the vicinity of the center O1 in the width direction of the base 51, and the long groove 36 of one vibrating arm 34 extends around a virtual line Y1 passing through the vicinity of the center O1 in the longitudinal direction. The extending portion 36a formed in this manner and the extending portion 37a formed by extending the long groove 37 of the other vibrating arm 35 are formed so as to be substantially symmetrical.

That is, the extending portions 36a and 37a not only concentrate the vibration transmitted to the base 51, but also actively guide the concentrated vibration to the vicinity of the center O1, and how the vibration on the extending portion 36a side is guided, The way in which the vibration on the side of the portion 37a is guided is the same, and the left and right balance of the base 51 is balanced around the virtual line Y1.
The central vicinity O1 in the present embodiment is set to be a fulcrum when the vibrating arm 34 and the vibrating arm 35 vibrate. Accordingly, in FIG. 3, the vibrating arm 34 on the left side of the imaginary line Y1 and the right side of the vibrating arm 34 are set. The balance with the vibrating arm 35 is taken.

Further, in order to prevent vibration leakage, the extending portions 36a and 37a are preferably formed at positions away from the fixed regions 52a and 52b. For this reason, the region on the opposite side of the fixed region 52a and 52b of the base 51 is provided. Is formed.
Furthermore, in order to prevent the vibration from being transmitted to an extra portion of the base 51 and reducing the vibration energy, the extending portions 36a and 37a are arranged in a range that does not hinder the functions of the extending portions 36a and 37a described above. It is formed along the outer edge of the piezoelectric vibrating piece 32 so as to have a substantially shortest distance to the vicinity O1. That is, in FIG. 3, since the outer edge from the vibrating arm 34 to the crotch M is formed in a substantially L shape on the left side of the virtual line Y1 of the piezoelectric vibrating piece 32, the extending portion 36a is also formed in a substantially L shape. The extending portion 37a is substantially symmetric with the extending portion 36a about the virtual line Y1.

  Note that the outer edge of the piezoelectric vibrating piece 32 is not neatly arranged in an L shape as shown in FIG. 3 due to the anisotropy of quartz, so the shape along the outer edge is roughly For example, as shown in FIG. 5A, the shape may be curved with a certain curvature. Moreover, as shown in FIG.5 (b), the extending | stretching part 36a and the extending | stretching part 37a may be integrally connected in center vicinity O1.

The extension portions 36a and 37a are not formed with the excitation electrodes 46 and 47 as provided in the vibrating arms 34 and 35, so that the base 51 does not actively vibrate. Yes. That is, as shown in FIG. 3, excitation electrodes 46 and 47 are routed around the base 51 including the extending portions 36a and 37a to form connection electrodes. By arranging the electrodes having different polarities so as not to face each other, it is possible to prevent the base 51 from vibrating positively.
Specifically, the electrode extracted from the excitation electrode 47 to the base passes through the vicinity of the center O1 and is connected to the extraction electrode 52a. The connection electrode passing through the vicinity of the center O1 is different in polarity. It is not arranged so as to face the excitation electrode 46. The excitation electrode 46 in the long groove 36 is formed on the groove-shaped bottom surface (a part of the bottom surface in FIG. 3) of the extending portion 36a and the inner side surface (the inner surface on the groove-like virtual line Y1 side) connected to the bottom surface. Connected to the excitation electrode 46 on the side surface of the vibrating arm 35 so as to avoid the crotch portion M, but connected to the groove-shaped bottom surface and the inner side surface of the extending portion 36a. These electrodes are not arranged so as to face the excitation electrode 47 having a different polarity.

  The base 51 has notches 54 and 54 formed between the fixed regions 52a and 52b and the vibrating arms 34 and 35, and in this embodiment, between the fixed regions 52a and 52b and the extending portions 36a and 37a. As a result, the vibrations of the vibrating arms 34 and 35 are hardly transmitted to the fixed regions 52a and 52b, thereby preventing vibration leakage.

The embodiment of the present invention is configured as described above, and the base 51 has extending portions 36a and 37a formed by extending the long grooves 36 and 37 of the pair of vibrating arms 34 and 35, respectively. When the vibrations 34 and 35 are transmitted to the base 51, they concentrate on the fragile extending portions 36 a and 37 a, thereby preventing vibration energy from being dispersed at the base 51. Therefore, the Q value can be increased by suppressing the base 51 from absorbing vibration energy.
Furthermore, the extending portions 36a and 37a are formed up to the vicinity of the center O1 in the width direction of the base 51, and the extending portions 36a extended from the vibrating arm 34 about the virtual line Y1 in the longitudinal direction passing through the vicinity of the center O1. The extending portion 37a extended from the vibrating arm 35 is substantially symmetric. Therefore, the vibration transmitted to the base 51 is transmitted in a balanced manner around both sides of the virtual line Y1, and stable vibration such as effectively preventing torsion of the base 51 can be achieved. Can be prevented. The vicinity of the center O1 becomes a fulcrum when the vibrating arm 34 and the vibrating arm 35 vibrate, thereby balancing the vibrations of the vibrating arm 34 on the left side and the vibrating arm 35 on the right side of the virtual line Y1, Stable vibration of the entire piezoelectric vibrating piece 32 is enabled.

FIG. 6 is a schematic perspective view of a piezoelectric vibrating piece 60 according to a first modification of the embodiment of the present invention. In FIG. 6, the excitation electrode is not shown for convenience of understanding.
In this figure, the same components as those of the piezoelectric vibrating piece 32 of FIGS. 1 to 5 are denoted by the same reference numerals, and redundant description will be omitted, and differences will be mainly described.

This piezoelectric vibrating piece 60 is mainly different from the above-described embodiment of the present invention in that long grooves 36 and 37 provided in the vibrating arms 34 and 35 are formed up to the tips of the vibrating arms 34 and 35. .
That is, the long grooves 36 and 37 penetrate through the tips of the vibrating arms 34 and 35, and the end surface on the free end side is also formed in an approximately H shape, so that the vibrating arms 34 and 35 are free from the root on the base 51 side. Even if any of the width direction is cut to the tip of the side, the end face is formed to be substantially the same.
By forming the long grooves 36 and 37 to the tip in this way, the frequency of the vibrating arms 34 and 35 is increased. For example, a weight having a specific gravity similar to or higher than that of the vibrating arms 34 and 35 is used. , 37, the frequency can be lowered.

  The first modification of the embodiment of the present invention is configured as described above. Since the long grooves 36 and 37 are formed up to the tips of the vibrating arms 34 and 35, the vibrating arms 34 and 35 are arranged from the root to the tip. Up to this, the entire structure is the same, and the entire vibrating arms 34 and 35 are in a stable bending vibration. Therefore, stable vibration is transmitted to the extending portions 36a and 37a, and vibration leakage can be effectively prevented as compared with the embodiment described above.

FIG. 7 is a schematic perspective view of a piezoelectric vibrating piece 70 according to a second modification of the embodiment of the present invention. In FIG. 7, the excitation electrode is not shown for convenience of understanding.
In this figure, the same components as those of the piezoelectric vibrating reeds 32 and 60 in FIGS. 1 to 6 are denoted by the same reference numerals, and redundant description will be omitted, and differences will be mainly described.

This piezoelectric vibrating piece 70 is mainly different from the above-described embodiment of the present invention and the first modification thereof in that bars along the width direction are provided in the long grooves 36 and 37 provided in the vibrating arms 34 and 35. It is a point that is formed.
That is, as shown in FIG. 7, the long grooves 36 and 37 of the vibrating arms 34 and 35 are each provided with a plurality of side bar-shaped support portions 62.

  Specifically, each support portion 62 is provided so as to cross the inside of each of the long grooves 36 and 37 in the width direction (X direction in FIG. 7). In addition, each support portion 62 includes material portions 34 a and 34 b constituting the vibrating arm 34 separated in the width direction by the long groove 36 and material portion 35 a constituting the vibrating arm 35 separated in the width direction by the long groove 37. , 35b are connected together. Furthermore, the support portion 62 in the present embodiment is integrated with the bottom portions 34 c and 35 c in the long grooves 36 and 37.

  The second modification of the embodiment of the present invention is configured as described above. Since the long grooves 36 and 37 are provided with the support portions 62, the support portions 62 are provided in the long grooves 36 and 37, respectively. The material 34 a, 34 b, 35 a, 35 b constituting the vibrating arm separated in the width direction by the long grooves 36, 37 are supported integrally with the bottom portions 34 c, 35 c of the steel plate so as not to be deformed. For this reason, the vibration arms 34 and 35 have enhanced rigidity in the torsional direction, and stable vibration is possible. Therefore, stable vibration is transmitted to the extending portions 36a and 37b, and vibration leakage can be prevented more than in the above-described embodiment.

The present invention is not limited to the above-described embodiment. Each configuration of each embodiment may be combined with each other as appropriate, or may be omitted and combined with other configurations not shown.
In addition, the piezoelectric device of the present invention can be applied regardless of its name, such as a piezoelectric oscillator, a piezoelectric vibrator, and a filter, as long as the package includes a piezoelectric vibrating piece.

1 is a schematic plan view of, for example, a piezoelectric vibrator that is a piezoelectric device according to an embodiment of the present invention. FIG. 2 is a schematic sectional view taken along line BB in FIG. 1. 1 is a schematic perspective view of a piezoelectric vibrating piece according to an embodiment of the present invention. FIG. 4 is a cross-sectional view taken along line CC in FIG. 3. The figure showing the shape different from FIG. 1 and FIG. 3 about the long groove extended | stretched by the base of this invention. The schematic perspective view of the piezoelectric vibrating piece which concerns on the 1st modification of embodiment of this invention. The schematic perspective view of the piezoelectric vibrating piece which concerns on the 2nd modification of embodiment of this invention. The schematic perspective view of the piezoelectric vibrating piece used for the conventional piezoelectric device. FIG. 9 is a schematic sectional view taken along line AA in FIG. 8.

Explanation of symbols

  28 ... Package, 30 ... Piezoelectric vibrator, 32, 60, 70 ... Piezoelectric vibrating piece, 34, 35 ... Vibrating arm, 36, 37 ... Long groove, 51 ... Base, 52a , 52b... Fixed region (extraction electrode).

Claims (8)

A piezoelectric vibrating piece comprising a pair of vibrating arms and a base having a fixed region connected to the package and connected to the pair of vibrating arms,
Each of the pair of vibrating arms has a long groove extending along the longitudinal direction,
The base has an extended portion formed by extending each long groove of the pair of vibrating arms to the vicinity of the center in the width direction,
An extending portion formed by extending one long groove of the pair of vibrating arms and an extending portion formed by extending the other long groove of the pair of vibrating arms are virtual in the longitudinal direction passing near the center. A piezoelectric vibrating piece characterized by being substantially symmetrical about a line.   The piezoelectric vibrating piece according to claim 1, wherein the extending portion is formed in a region opposite to the fixed region.   3. The piezoelectric vibrating piece according to claim 1, wherein the extending portion is formed along the outer edge so as to have a substantially shortest distance to the vicinity of the center in the width direction of the base portion.   4. The piezoelectric vibrating piece according to claim 1, wherein an excitation electrode for vibrating the vibrating arm is not formed on the extending portion. 5.   5. The piezoelectric vibrating piece according to claim 1, wherein the base portion has a notch portion between the fixed region and the extending portion.   The piezoelectric vibrating piece according to claim 1, wherein the long groove is formed up to a tip of the vibrating arm.   In the long groove, there is formed a support portion which is provided so as to cross in the width direction and integrally connects the materials constituting the vibrating arm separated in the width direction by the long groove. Item 7. The piezoelectric vibrating piece according to any one of Items 1 to 6. A piezoelectric device comprising a package and a piezoelectric vibrating piece having a base provided with a fixed region to be bonded to the package and having a pair of vibrating arms extending in parallel from the base,
Each of the pair of vibrating arms has a long groove extending along the longitudinal direction,
The base has an extended portion formed by extending each long groove of the pair of vibrating arms to the vicinity of the center in the width direction,
An extending portion formed by extending one long groove of the pair of vibrating arms and an extending portion formed by extending the other long groove of the pair of vibrating arms are virtual in the longitudinal direction passing near the center. A piezoelectric device characterized by being substantially symmetrical about a line.

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