JP2006197477A - Piezoelectric device package and piezoelectric device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a package for a piezoelectric device in which a piezoelectric vibration reed can be easily mounted with high accuracy, and a piezoelectric device using the package for a piezoelectric device. <P>SOLUTION: In the package for piezoelectric device provided with a cavity S surrounded with two long inner walls 46 and 47 that are parallel to each other and in a lengthwise direction and two short inner walls 48 and 49 that are in a widthwise direction so as to be almost perpendicular to the long inner walls, and two mounted electrodes 31 and 32 provided on the bottom in the cavity S, the two mounted electrodes 31 and 32 are respectively arranged along each of the two long inner walls 46 and 47 so as not to be adjacent at least to the short inner walls 48 and 49. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a piezoelectric device package having a cavity for housing a piezoelectric vibrating piece, and a piezoelectric device using the package.

FIG. 8 is a schematic plan view of a conventional piezoelectric device.
In this figure, the piezoelectric device 1 shows an example of a piezoelectric vibrator, and a piezoelectric vibrating piece 3 is accommodated in a package 2.
The package 2 has a cavity 8 that accommodates the piezoelectric vibrating piece 3. The cavity 8 is surrounded by inner walls 2 a, 2 b, 2 c, 2 d formed so that adjacent inner walls are substantially perpendicular, and a mount electrode 4 a joined to the piezoelectric vibrating reed 3 on the bottom surface of the cavity 8. , 4b are provided.
The mount electrode 4a is disposed at the corner so as to be adjacent to both the inner wall 2d along the short side direction and the inner wall 2a along the long side direction. The mount electrode 4b is also arranged at the corner so as to be adjacent to both the inner wall 2d along the short side direction and the inner wall 2c along the long side direction. The mount electrodes 4a and 4b have different polarities with a predetermined interval W so as not to contact each other.

  The piezoelectric vibrating reed 3 has a base 6 and vibrating arms 7 and 7 extending in parallel with each other from the base 6, and the so-called tuning fork in which the base 6 is joined to the package 2 and fixed in a cantilever manner. This is a type of piezoelectric vibrating piece. That is, the conductive adhesives 5, 5 are applied on the mount electrodes 4 a, 4 b described above, and the base 6 of the piezoelectric device 1 is placed on the conductive adhesives 5, 5. Is mounted on the package 2.

Japanese Patent Laid-Open No. 2004-266763

However, in recent years, the piezoelectric device 1 has been remarkably miniaturized, and the area where the piezoelectric vibrating reed 3 is mounted has to be reduced. That is, in order to ensure a predetermined oscillation frequency, it is preferable not to change the lengths of the vibrating arms 7 and 7 of the piezoelectric vibrating piece 3. For this reason, in order to reduce the size of the piezoelectric device 1, the base 6 is minimized. Therefore, it can be said that the mount electrodes 4a and 4b joined to the minimized base portion 6 are extremely miniaturized.
Therefore, it has become difficult to accurately form the minimized mount electrodes 4a and 4b at the corners of the package 2 as in the prior art. Moreover, it is becoming more difficult to accurately apply the adhesives 5 and 5 to the miniaturized mount electrodes 4a and 4b at the corners to mount the piezoelectric vibrating reed 3 with high accuracy.

  An object of the present invention is to provide a package for a piezoelectric device that can mount a piezoelectric vibrating piece easily and accurately, and a piezoelectric device using the package.

  According to the first invention, the above-described object is achieved by two long inner walls that are parallel to each other and along the longitudinal direction, and two that are along the short direction so as to be substantially perpendicular to the long inner wall. A package for a piezoelectric device comprising a cavity surrounded by a short inner wall and two mount electrodes provided on a bottom surface in the cavity, each of the two mount electrodes being adjacent to at least the short inner wall This is achieved by a package for a piezoelectric device which is arranged along each of the two long inner walls.

According to the configuration of the first invention, the mount electrode is formed so as not to be adjacent to at least the short inner wall. For this reason, at least as long as the mount electrode does not have to be arranged at the corner in the cavity, the mount electrode can be easily formed, and the adhesive can be easily applied to the mount electrode.
In addition, since each of the two mount electrodes is disposed along each of the two long inner walls, the two mount electrodes can be formed larger than disposed along the short inner wall. Further, since the two long inner walls are parallel to each other, the mount electrode can be formed large along the longitudinal direction without worrying about short circuit between the mount electrodes. Therefore, it becomes easy to form the mount electrode, and it becomes easy to apply the adhesive to the mount electrode.
Furthermore, if the mount electrode is formed large along the longitudinal direction, the portion where the adhesive supports the piezoelectric vibrating piece increases in the longitudinal direction, and when the piezoelectric vibrating piece is mounted, the end in the longitudinal direction is inclined in the thickness direction. Can be effectively prevented.
Thus, it is possible to provide a package for a piezoelectric device that can mount the piezoelectric vibrating piece easily and accurately.

According to a second aspect of the present invention, in the configuration of the first aspect, the mount electrode is arranged such that the approximate center in the longitudinal direction is arranged near the center in the longitudinal direction of the long inner wall.
According to the configuration of the second invention, the mount electrode is disposed near the center in the longitudinal direction of the inner wall having a long longitudinal center, so that it approaches the corner portion in the cavity from the first invention. As compared with the first aspect of the invention, it is possible to mount the piezoelectric vibrating piece more easily and accurately.

A third invention is characterized in that, in the configuration of either the first or second invention, the mount electrode is elevated with respect to the bottom surface in the cavity.
According to the configuration of the third aspect of the invention, the mount electrode is raised with respect to the bottom surface in the cavity, so that the piezoelectric vibrating piece bonded and fixed to the mount electrode has a considerable height from the bottom surface in the cavity. Will have. Therefore, even if the piezoelectric vibrating piece swings toward the bottom surface in the cavity, it is possible to effectively prevent the piezoelectric vibrating piece from contacting the bottom surface in the cavity.

According to a fourth aspect of the present invention, in any one of the first to third aspects, a recess is formed in the vicinity of one end in the longitudinal direction on the bottom surface in the cavity.
According to the configuration of the fourth aspect of the invention, since the concave portion is formed near one end in the longitudinal direction on the bottom surface in the cavity, it is assumed that one end in the longitudinal direction of the piezoelectric vibrating piece to be bonded to the package is swung in the thickness direction. Moreover, it can prevent contacting the bottom surface in a cavity.

According to a fifth aspect of the present invention, in any one of the first to third aspects, the bottom surface in the cavity has recesses formed in the vicinity of both ends in the longitudinal direction.
According to the fifth aspect of the invention, since the recesses are formed near both ends in the longitudinal direction on the bottom surface in the cavity, it is assumed that both ends in the longitudinal direction of the piezoelectric vibrating piece to be bonded to the package are swung in the thickness direction. Moreover, it can prevent contacting the bottom surface in a cavity.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, a through-hole that communicates the inside of the cavity with the outside is formed in the bottom surface of the cavity.
According to the configuration of the sixth aspect of the invention, a through hole that connects the inside of the cavity and the outside is formed on the bottom surface in the cavity. For this reason, even after the piezoelectric vibrating piece is bonded to the package with the adhesive and the lid is bonded to the package with the adhesive, the gas emitted from the adhesive can be discharged through the through hole.
By the way, as described in the first aspect of the invention, the volume of the cavity in the package decreases as much as the mount electrode is formed along the longitudinal direction. Accordingly, the gas in the cavity can be easily discharged from the through hole.

  According to the seventh aspect of the present invention, there is provided a piezoelectric vibrating piece having a plurality of vibrating arms extending in parallel from the base, two long inner walls that are parallel to each other along the longitudinal direction, and the long inner wall. And a package having two cavities surrounded by two short inner walls along the short-side direction so as to be substantially perpendicular to each other, and having two mount electrodes provided on the bottom surface in the cavity Each of the two mount electrodes is arranged along each of the two long inner walls so as not to be adjacent to at least the short inner wall, and the piezoelectric vibrating piece includes the mount electrode and The fixed portion to be joined is achieved by the piezoelectric device package configured to be joined to the base portion.

According to the configuration of the seventh invention, since each of the two mount electrodes is arranged along each of the two long inner walls so as not to be adjacent to at least the short inner wall, similarly to the first invention. The mount electrode can be easily formed, and an adhesive can be easily applied to the mount electrode.
In addition, since the fixed part to be joined to the mount electrode is joined to the base, the piezoelectric vibrating piece is mounted with the position of the fixed part and the mount electrode aligned. become. At this time, as described above, the mount electrode is not arranged at the corner in the cavity, and is formed so as to be large along the longitudinal direction. Therefore, the position of the fixed portion of the piezoelectric vibrating piece and the mount electrode The piezoelectric vibrating piece can be mounted with high accuracy.

1 and 2 show a piezoelectric device 30 according to a first embodiment of the present invention. FIG. 1 is a schematic plan view of the piezoelectric device 30, and FIG. 2 is a schematic sectional view taken along line AA of FIG. is there.
Note that the piezoelectric device means all products in which a piezoelectric vibrating piece is accommodated in a package regardless of the name of a piezoelectric vibrator or a piezoelectric oscillator.
Moreover, the part shown by the parallel oblique line of FIG.1 and FIG.2 is shown for the convenience of understanding, and does not represent a cross section.

The piezoelectric device 30 in these drawings shows an example in which a piezoelectric vibrator is configured, and the piezoelectric vibrating piece 20 is accommodated in a package 36.
In this embodiment, the piezoelectric device package 36 is formed by, for example, laminating a first substrate 30a and a second substrate 30b formed by molding an aluminum oxide ceramic green sheet as an insulating material. It is formed by sintering.

The first substrate 30a is formed with a predetermined hole inside thereof, so that when the first substrate 30a is stacked on the second substrate 30b, a predetermined internal space S is formed inside the package 36. This internal space S becomes a cavity S for accommodating the piezoelectric vibrating piece 27.
Specifically, the hole provided in the first substrate 30a has a substantially rectangular horizontal cross section, and therefore the adjacent inner walls in the cavity S are substantially perpendicular to each other. That is, the cavity S is parallel to each other and has long inner walls 46 and 47 along the longitudinal direction, and two short inner walls along the short direction in contact with the long inner walls 46 and 47 so as to be substantially perpendicular to each other. It is formed so as to be surrounded by 48 and 49.

  Further, a brazing material 44 such as low melting point glass is applied to the opening end surface of the first substrate 30a on the side opened to the top in FIG. It is sealed. Even after the lid 39 is sealed, the lid 39 transmits light so that the excitation light or weight provided on the piezoelectric vibrating piece 20 can be irradiated with laser light and the frequency can be adjusted by the mass reduction method. For example, glass.

Further, on the bottom surface in the cavity S, that is, the surface exposed to the cavity S of the second substrate 30b, for example, two mount electrodes 31 and 32 formed by nickel plating and gold plating on a tungsten metallization are provided.
As shown in FIG. 2, each of the mount electrodes 31 and 32 is connected to the mounting terminal portions 38 and 38 through the conductive portion 35 in the via hole of the second substrate 30b, thereby different from each other. It becomes an electrode and serves as an electrode for supplying a drive voltage to the piezoelectric vibrating piece.

Here, each of the pair of mount electrodes 31 and 32 is disposed along each of the two long inner walls 46 and 47 so as not to be adjacent to at least the short inner walls 48 and 49.
Specifically, the mount electrodes 31 and 32 of this embodiment are arranged adjacent to long inner walls 46 and 47 formed in parallel to each other. The mount electrodes 31 and 32 are formed so that the approximate center P3 in the longitudinal direction is disposed near the center in the longitudinal direction of the long inner walls 46 and 47, and extends uniformly from the center P3 toward both ends. Yes.

A conductive adhesive such as silicone, epoxy, or polyimide is applied to the upper surfaces of the mount electrodes 31 and 32 as the adhesives 43 and 43, and the piezoelectric vibrating reed 20 is formed on the adhesives 43 and 43. The mounting electrodes 31 and 32 and the piezoelectric vibrating piece 20 are electrically and mechanically connected by being mounted and the adhesives 43 and 43 being cured.
1 and 2, a conductive adhesive is used as the adhesive 43, but the present invention is not limited to this. For example, electrical connection is performed by wire bonding, and the adhesive is mechanically used. Only an adhesive that is bonded may be used.

The piezoelectric vibrating piece 12 is formed of, for example, quartz or the like, and other piezoelectric materials such as lithium tantalate and lithium niobate can be used.
In the case of the present embodiment, the piezoelectric vibrating piece 20 is formed in a small size, and in order to obtain a required performance, a pair of vibrating arms 24 extending in parallel from the base 26 to the right in FIG. 25.

  The base portion 26 is a portion for supporting the pair of vibrating arms 24 and 25. In addition, the base portion 26 of the present embodiment is also a portion for supporting two fixing portions 27 and 28 for joining the piezoelectric vibrating piece 20 to the mount electrodes 31 and 32. That is, the vibrating arms 24, 25, the base portion 26, and the fixing portions 27, 28 are integrally formed, and the fixing portions 27, 28 are positioned at the positions of the mount electrodes 31, 32 when the piezoelectric vibrating reed 20 is mounted. It is formed to match.

Specifically, a pair of fixing portions 27 and 28 are formed on the outer sides of the pair of vibrating arms 24 and 25 from the base portion 26 so as to sandwich the vibrating arms 24 and 25, and the long inner walls 46 and 47 of the package 36. They are formed to extend in parallel to each other in the same direction.
Then, the vibration arms 24 and 25 are shorter than the vibration arms 24 and 25 by a predetermined length L1 so as to avoid the horizontal vibration of the vibration arms 24 and 25 (so as not to contact the vibration arms 24 and 25 which are vibrated as indicated by the dotted lines in FIG. 1). In addition to being formed, the vibrating arms 24 and 25 are formed away from the outer side surfaces of the vibrating arms 24 and 25 by a predetermined width W1. More preferably, in the width direction (short direction), the position P1 of the tip of the vibrating arms 24, 25 when the vibrating arms 24, 25 vibrate and the position P2 of the fixing portions 27, 28 are made substantially the same. ing.

Each of the vibrating arms 24 and 25 has a long groove (not shown) extending in the longitudinal direction on each of the front and back surfaces thereof, and has a H-shaped cross section. Excitation electrodes 33a and 34a are formed in the long groove, and the excitation electrode 34a is formed on the side surface of the vibrating arm 24 so as to face the excitation electrode 33a in the long groove, and is opposed to the excitation electrode 34a in the long groove. In this way, the excitation electrode 33 a is formed on the side surface of the vibrating arm 25.
The excitation electrode 34a is connected to an electrode part 34b formed on at least the surface of the fixed part 27 on the side of the mount electrode 31 via an extraction electrode 34c drawn to the base part 26, and the excitation electrode 33a is connected to the base part 26 is connected to an electrode part 33 b formed on at least the surface of the fixed part 28 on the side of the mount electrode 32 via an extraction electrode 33 c drawn to 26.
As described above, the long grooves are provided, and the electrodes in the long grooves and the electrodes on the side surfaces facing the long grooves are arranged so as to have different polarities, so that the electric field efficiency in each arm is increased, and the vibrating arms 24 and 25 are reduced in size. It is possible.

The first embodiment of the present invention is configured as described above. Since the mount electrodes 31 and 32 are formed so as not to be adjacent to at least the short inner walls 48 and 49, at least the mount electrodes 31 and 32 are provided. It is not necessary to arrange at the corners in the cavity S.
Each of the mount electrodes 31 and 32 is disposed along each of the two long inner walls 46 and 47, and the long inner walls 46 and 47 are parallel to each other. For this reason, the mount electrodes 31 and 32 can be formed large along the longitudinal direction without worrying about a short circuit between the mount electrodes 31 and 32 having different polarities.
Therefore, the mount electrodes 31 and 32 can be easily formed, and the adhesives 43 and 43 can be easily applied to the mount electrodes 31 and 32.
Furthermore, if the mount electrodes 31 and 32 are formed to be large along the longitudinal direction, when the piezoelectric vibrating piece 20 is mounted, the longitudinal ends 20a and 20b of the piezoelectric vibrating piece 20 as shown by the dotted line in FIG. It can prevent effectively that it joins inclining in the thickness direction.

3 and 4 show a piezoelectric device 50 according to a second embodiment of the present invention, in which FIG. 3 is a schematic plan view of the piezoelectric device 50, and FIG. 4 is a schematic sectional view taken along line BB in FIG. is there.
In FIG. 3, the piezoelectric vibrating reed is omitted for convenience of understanding. 3 and 4 are shown for the convenience of understanding, and do not represent a cross section or the like.
In these drawings, the portions denoted by the same reference numerals as those used in the description of FIG. 1 and FIG. 2 have the same configuration, and therefore, redundant description will be omitted and the following description will focus on the differences.

The piezoelectric device 50 is mainly different from the piezoelectric device 30 of FIGS. 1 and 2 in that the mount electrodes 31 and 32 are raised with respect to the bottom surface in the cavity S.
Specifically, in the second embodiment, the mount electrodes 31 and 32 are connected to the mounting terminal portions 38 and 38 via the conductive pattern 52 provided in the package 36. 4, the conductive pattern 52 exposed in the cavity S of the second substrate 30b is plated with nickel 52b and gold 52c on the metallized tungsten 52a. Is formed.

  Here, the mount electrodes 31 and 32 are also formed using tungsten 52a, nickel 52b, and plating 52c when forming the conductive pattern 52. However, the position where the mount electrodes 31 and 32 are formed is tungsten. Tungsten 54 is further metallized on the metallized 52 a, whereby the mount electrodes 31 and 32 are formed thicker than the conductive pattern 52.

  The second embodiment of the present invention is configured as described above, and thus exhibits the same effects as those of the first embodiment. Furthermore, since the mount electrodes 31 and 32 are higher than the bottom surface in the cavity S, the piezoelectric vibrating piece 20 has a considerable height from the bottom surface in the cavity S. Therefore, even if the distance between the fixing portions 27 and 28 of the piezoelectric vibrating piece 20 and the vibrating arms 24 and 25 is increased, the piezoelectric vibrating piece 20 can easily swing toward the bottom surface in the cavity S. Can be effectively prevented from contacting the bottom surface in the cavity S.

5 to 7 show a piezoelectric device 60 according to a third embodiment of the present invention, in which FIG. 5 is a schematic plan view of the piezoelectric device 60, and FIG. 6 is a schematic cross-sectional view taken along the line CC of FIG. FIG. 7 is a schematic sectional view taken along line DD of FIG.
In FIG. 5, for convenience of understanding, long grooves and excitation electrodes provided in the piezoelectric vibrating piece are omitted. Moreover, the part shown by the parallel oblique line of FIG. 7 has shown each electrode instead of a cross section.
In these drawings, the portions denoted by the same reference numerals as those used in the description of FIG. 1 and FIG. 2 have the same configuration, and therefore, redundant description will be omitted and the following description will focus on the differences.
The piezoelectric device 60 is different from the piezoelectric device 30 of FIGS. 1 and 2 in that a recess and a through hole are provided on the inner bottom surface of the package.

  That is, a first recess 67 is formed near the one end in the longitudinal direction on the bottom surface in the cavity S of the piezoelectric device 60. The first concave portion 67 is formed directly below the tip of the vibrating arms 24 and 25 that most affect the oscillation frequency, corresponding to the vicinity of the tip opposite to the base 26 side. A bottomed hole for preventing the vibrating arms 24 and 25 from coming into contact with the bottom surface in the cavity S even if the end on the end side swings toward the bottom surface in the cavity S (direction F1 in FIG. 6). is there. In the present embodiment, the first recess 67 is formed by forming the bottom of the package 36 by two substrates 36b and 36c, forming a through hole in the substrate 36c on the cavity S side, and laminating the substrate 36c on the substrate 36d. It is formed by doing.

  Further, a second recess 68 is also formed on the bottom surface in the cavity S of the piezoelectric device 60 on the side opposite to the first recess 67 in the longitudinal direction, thereby forming recesses near both ends in the longitudinal direction. It has become so. The second recess 68 is formed corresponding to the vicinity of the end of the piezoelectric vibrating piece 20 opposite to the vibrating arms 24 and 25 side, and the base 26 of the piezoelectric vibrating piece 20 or the base 26 and the fixed portion. Even if the portion that integrally connects with 27 and 28 swings toward the bottom surface in the cavity S, it is a hole with a bottom for preventing contact with the bottom surface in the cavity S. Similarly to the first recess 67, the second recess 68 is formed by forming a through hole in the substrate 36c on the cavity S side and laminating the substrate 36c on the substrate 36d.

Furthermore, a through-hole 62 that connects the inside of the cavity S and the outside is formed on the bottom surface of the cavity S of the piezoelectric device 60. The through-hole 62 is a hole for discharging gas generated from the adhesive 43 and the brazing material 44 after the piezoelectric vibrating piece 20 is mounted with the adhesive 43 and the package 36 is covered with the brazing material 44, for example. Yes, it is sealed with a molten sealing material 64 after the gas is discharged.
Specifically, the through hole 62 is disposed so as to be sandwiched between the mount electrode 31 and the mount electrode 32. The through hole 62b provided in the substrate 36c on the cavity S side and the lowermost substrate 36d with the main surface exposed to the outside are formed from a through hole 62a larger than the through hole 62b. When stacked on the substrate 36d, a step portion 66 is formed. The step portion 66 is a means for preventing the sealing material 64 before melting from passing through the through hole 62 when the sealing material 64 before melting is placed in the through hole 62.

  Further, as shown in FIG. 7, in the third embodiment, the mount electrode 31 is connected to the conductive portion 72 in the via hole of the substrate 36c, and this conductive portion 72 is a conductive pattern 74 provided on the surface of the substrate 36d. It is connected to the mounting terminal part 38 via Similarly, the mount electrode 32 is connected to the mounting terminal portion 38 via a conductive portion or a conductive pattern in the via hole.

The third embodiment of the present invention is configured as described above. For this reason, the same effect as that of the first embodiment is exhibited. In addition, in the bottom surface in the cavity S of the package 36, recesses are formed near both ends in the longitudinal direction of the piezoelectric vibrating piece 20. Therefore, even if the distance between the fixing portions 27 and 28 of the piezoelectric vibrating piece 20 and the vibrating arms 24 and 25 is increased, the piezoelectric vibrating piece 20 can easily swing toward the bottom surface in the cavity S. Can be effectively prevented from contacting the bottom surface in the cavity S.
Furthermore, a through-hole 62 that connects the inside of the cavity S and the outside is formed on the bottom surface of the package 36 in the cavity S. For this reason, the adhesive 43 used for mounting the piezoelectric vibrating piece 20 is used more than in the past, and even if a large amount of gas is generated from the adhesive 43, the gas is discharged from the through-hole 62 to obtain the oscillation frequency. It is possible to prevent adverse effects.

  The present invention is not limited to the above-described embodiment. Each configuration of the embodiment and each modified example can be appropriately combined or omitted, and can be combined with other configurations not shown.

1 is a schematic plan view of a piezoelectric device according to a first embodiment of the present invention. FIG. 2 is a schematic sectional view taken along line AA in FIG. 1. The schematic plan view of the piezoelectric device which concerns on the 2nd Embodiment of this invention. FIG. 4 is a schematic sectional view taken along line B-B in FIG. 3. The schematic plan view of the piezoelectric device which concerns on the 3rd Embodiment of this invention. CC sectional schematic sectional drawing of FIG. FIG. 6 is a schematic sectional view taken along line D-D in FIG. 5. The schematic plan view of the conventional piezoelectric device.

Explanation of symbols

  30, 50, 60 ... Piezoelectric device, 20 ... Piezoelectric vibrating piece, 24, 25 ... Vibrating arm, 26 ... Base, 27, 28 ... Fixed part, 31, 32 ... Mount Electrode 36 ... Package 46,47 ... Long inner wall 48,49 ... Short inner wall S ... Cavity

Claims (7)

A cavity surrounded by two long inner walls parallel to each other along the longitudinal direction and two short inner walls along the short direction so as to be substantially perpendicular to the long inner wall; A package for a piezoelectric device having two mount electrodes provided on the bottom surface,
Each of the two mount electrodes is disposed along each of the two long inner walls so as not to be adjacent to at least the short inner wall. A package for a piezoelectric device, wherein:   2. The package for a piezoelectric device according to claim 1, wherein the mount electrode has a substantially center in a longitudinal direction disposed near a center in a longitudinal direction of the long inner wall.   3. The package for a piezoelectric device according to claim 1, wherein the mount electrode is elevated with respect to a bottom surface in the cavity.   The package for a piezoelectric device according to any one of claims 1 to 3, wherein a concave portion is formed near one end in a longitudinal direction on a bottom surface in the cavity.   The package for a piezoelectric device according to any one of claims 1 to 3, wherein concave portions are formed in the vicinity of both ends in the longitudinal direction on the bottom surface in the cavity.   The package for a piezoelectric device according to any one of claims 1 to 5, wherein a through-hole that communicates the inside of the cavity and the outside is formed in a bottom surface of the cavity. A piezoelectric vibrating piece having a plurality of vibrating arms extending in parallel from the base;
A cavity surrounded by two long inner walls parallel to each other and along the longitudinal direction, and surrounded by two short inner walls along the short direction so as to be substantially perpendicular to the long inner wall; A piezoelectric device comprising: a package having two mount electrodes provided on an inner bottom surface thereof;
Each of the two mount electrodes is disposed along each of the two long inner walls so as not to be adjacent to at least the short inner wall,
The piezoelectric device is characterized in that the piezoelectric vibrating piece is configured such that a fixed portion joined to the mount electrode is joined to the base.

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