JP5585240B2 - Vibrating piece and vibrating device - Google Patents

Description

  The present invention relates to a piezoelectric vibrating piece and a piezoelectric device including the piezoelectric vibrating piece.

  In Patent Document 1, a piezoelectric vibrating reed main body having a base and a vibrating arm portion extending from one end of the base, and a short side and a short side provided along the other end of the base provided to be connected to the base Provided on a support portion (hereinafter referred to as a holding portion) having a long side portion extending along the longitudinal direction of the piezoelectric vibrating reed body from the end portion of the piezoelectric portion, and on the distal end side and the short side portion of the long side portion There is disclosed a piezoelectric vibrating piece having a mounted portion (hereinafter referred to as a support portion).

JP 2004-343541 A (FIGS. 1 and 4)

According to Patent Literature 1, the piezoelectric vibrating piece is formed in an asymmetric shape with respect to the piezoelectric vibrating piece main body in order to reduce the size of the piezoelectric vibrating piece compared to the conventional configuration (see FIGS. 1 and 4 of Patent Literature 1). ).
The piezoelectric vibrating piece is bonded to the inner bottom surface of the package in which the piezoelectric vibrating piece is accommodated by bonding support portions provided on the front end side and the short side portion of the long side portion of the holding portion. It is possible to be mounted on a package while maintaining parallelism.

However, Patent Document 1 does not describe or suggest the positional relationship between the support portion of the piezoelectric vibrating piece and the center of gravity of the piezoelectric vibrating piece. From this, it is considered that the conventional technology of Patent Document 1 does not consider this point.
As a result, the piezoelectric vibrating piece generates a force that tilts toward the center of gravity due to its own weight when the center of gravity of the piezoelectric vibrating piece is not located in the region connecting the support portions of the holding portion that is asymmetric in plan view. There is a possibility that it is difficult to mount the package in a state in which the parallelism with the inner bottom surface of the package is maintained.

As a result, the piezoelectric device including the piezoelectric vibrating piece needs to be set with a wider gap in consideration of the inclination of the piezoelectric vibrating piece so that the inner bottom surface of the package and the piezoelectric vibrating piece do not interfere with each other. For this reason, there is a problem that the package for accommodating the piezoelectric vibrating piece becomes thick and it is difficult to reduce the total thickness.
In addition, in the piezoelectric device, since the piezoelectric vibrating piece is easily inclined, the productivity (yield) when the piezoelectric vibrating piece is bonded to the package may be lowered.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.
A resonator element according to an embodiment of the present invention includes a base, a vibrating portion including a vibrating arm extending in a first direction from one end of the base, and the one end of the base. A holding portion connected to the other end opposite to the first portion, and the holding portion is along the first direction so that the vibrating portion is disposed therebetween in plan view. A first arm portion including a first support portion and a second support portion disposed closer to the base end side than the first support portion; and extending along the first direction. A second arm portion that is extended and is provided with a third support portion and shorter in length than the first arm portion, the base portion, the vibration portion, and the holding portion, Is a region surrounded by an imaginary line connecting the first support portion, the second support portion, and the third support portion in the plan view. Characterized in that it is located within.
In the resonator element according to another aspect of the invention, the distance from the base end of the first arm portion to the second support portion is greater than the distance from the base end of the second arm portion to the third support portion. It is also characterized by its long length.
A vibrating piece according to another embodiment of the present invention is characterized in that the center of the vibrating portion is disposed closer to the first arm portion in the plan view.
A resonator element according to another aspect of the invention includes a width along a second direction intersecting the first direction where the first support portion of the first arm portion is disposed, and the The width along the second direction where the second support portion is disposed is greater than the width along the second direction where the third support portion of the second arm portion is disposed. It is also characterized by its wideness.
According to another aspect of the invention, the vibrator includes a plurality of vibrating arms.
In the resonator element according to another aspect of the invention, the vibrating arm is provided on at least one of the first main surface and the second main surface in a front-back relationship along the first direction. It is characterized by including the groove part which is.
In the resonator element according to another aspect of the invention, the vibrating arm is connected to an arm portion disposed on the one end portion side of the base portion and a distal end side of the arm portion in the first direction. And a weight portion having a width wider than that of the arm portion.
A resonator element according to another aspect of the invention includes a resonator element, wherein the base portion is disposed between the one end portion and the other end portion, and is cut out along the second direction. A notch is provided.
A vibrating device according to another embodiment of the present invention includes the vibrating piece and a package in which the vibrating piece is housed, and the first supporting portion, the second supporting portion, and the third The support portion is supported by the package.

  [Application Example 1] A piezoelectric vibrating piece according to this application example is a piezoelectric vibrating piece including a base, at least one vibrating arm extending from the base, and a holding part connected to the base. The base portion has a cutout portion cut out in a direction intersecting with the extending direction of the vibrating arm, and the vibrating arm includes an arm portion located on the base side and a distal end side from the arm portion. A weight portion that is positioned and wider than the arm portion, and a groove portion that is formed along at least one of the main surfaces along a direction in which the vibrating arm extends, and the holding portion is one of the vibrating arms. A first arm portion extending along the side, and a second arm portion extending along the other side of the vibrating arm and shorter than the first arm portion, and a distal end side and a root of the first arm portion A support portion supported by an external member is provided on the side and the second arm portion. The center of gravity of the piezoelectric vibrating piece is located in the bent region, and the distance from the base of the first arm to the support on the base of the first arm is from the base of the second arm to the first. It is longer than the distance to the said support part of 2 arms.

According to this, the piezoelectric vibrating reed is provided with support portions on the distal end side and the base side and the second arm portion of the first arm portion of the holding portion, and in a region connecting the support portions in plan view. The center of gravity of the piezoelectric vibrating piece is located.
As a result, when the piezoelectric vibrating piece is supported by the external member, inclination due to its own weight is avoided, so that the piezoelectric vibrating piece can be joined to the external member while maintaining parallelism with the support surface of the external member. It becomes possible.
Piezoelectric vibrating pieces with grooves and weights on the vibrating arm tend to be located closer to the tip of the vibrating arm, so the piezoelectric vibrating piece is bonded to the external member while maintaining parallelism with the support surface of the external member. In order to achieve this, the above configuration is extremely effective.

Further, the piezoelectric vibrating piece has a distance from the base of the first arm portion of the holding portion to the support portion on the base side of the first arm portion from the distance from the base of the second arm portion to the support portion of the second arm portion. It is configured to be long.
As a result, the piezoelectric vibrating piece is less likely to resonate between the first arm and the second arm during normal vibration of the vibrating arm or an external impact. The vibration characteristics can be improved.

  Application Example 2 In the piezoelectric vibrating piece according to the application example described above, the vibrating arm is disposed closer to the first arm portion than between the first arm portion and the second arm portion of the holding portion. Preferably it is.

  According to this, since the vibrating arm is arranged closer to the first arm than the middle between the first arm and the second arm of the holding portion, the center of gravity of the piezoelectric vibrating piece is the first. It becomes close to one arm part, and it becomes easy to position the center of gravity of the piezoelectric vibrating piece in the region connecting the support parts.

  Application Example 3 In the piezoelectric vibrating piece according to the application example described above, the width of the portion of the holding portion including the support portions of the first arm portion is the width of the portion of the second arm portion including the support portions. A wider one is preferred.

  According to this, since the width of the portion including each support portion of the first arm portion in the holding portion is wider than the width of the portion including the support portion of the second arm portion, the piezoelectric vibrating piece has the first arm portion. As the mass increases, the center of gravity of the piezoelectric vibrating piece becomes closer to the first arm portion, and it becomes easier to position the center of gravity of the piezoelectric vibrating piece within the region connecting the support portions.

  Application Example 4 In the piezoelectric vibrating piece according to the application example described above, it is preferable that a plurality of the vibrating arms are provided, and the tuning fork is configured to include the plurality of vibrating arms and the base portion.

  According to this, since the piezoelectric vibrating piece includes a plurality of vibrating arms and a base, and constitutes a tuning fork, it becomes a tuning fork type piezoelectric vibrating piece that easily obtains excellent vibration characteristics, and thus the vibration characteristics are improved. be able to.

  Application Example 5 A piezoelectric device according to this application example includes the piezoelectric vibrating piece according to any one of the application examples described above and a package that accommodates the piezoelectric vibrating piece, and the support portion of the piezoelectric vibrating piece includes It is supported by the package.

According to this, since the piezoelectric device includes the piezoelectric vibrating piece according to any one of the application examples described above, and the support portion of the piezoelectric vibrating piece is supported by the package, the piezoelectric device has a support surface of the package as an external member. The piezoelectric vibrating piece can be bonded to the package while maintaining parallelism.
As a result, the piezoelectric device does not need to have a wide gap between the two, so that the total thickness can be reduced.
In addition, since the piezoelectric device can hold the piezoelectric vibrating piece parallel to the support surface of the package, the productivity when the piezoelectric vibrating piece is bonded to the package can be improved.

  Application Example 6 In the piezoelectric device according to the application example described above, when the weight portion of the vibrating arm is displaced beyond a predetermined displacement amount in a plan view, the tip portion of the first arm portion on the one side The distance between the weight portion, the first arm portion, and the buffer portion is in contact with the buffer portion formed on the other side so as to protrude from the inner wall of the package toward the vibrating arm side. Is preferably set.

According to this, in the piezoelectric device, when the weight portion of the vibrating arm is displaced beyond a predetermined displacement amount, the piezoelectric device comes into contact with the distal end portion of the first arm portion on one side and the buffer portion of the package on the other side. Surface contact.
Therefore, in the piezoelectric device, the impact force applied to the weight portion of the vibrating arm at the time of impact such as dropping is alleviated by the bending of the tip of the first arm portion on one side, and the buffer portion of the package on the other side. Can be dispersed by the surface contact with each other, and damage to the weight portion (vibrating arm) can be reduced.

It is a schematic diagram which shows schematic structure of the crystal oscillator of this embodiment, (a) is a top view, (b), (c) is sectional drawing of (a). It is a schematic diagram which shows schematic structure of the crystal oscillator of the modification 1, (a) is a top view, (b), (c) is sectional drawing of (a). FIG. 9 is a schematic plan view showing a schematic configuration of a crystal resonator according to Modification 2.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings.

(Embodiment)
FIG. 1 is a schematic diagram showing a schematic configuration of a crystal resonator as a piezoelectric device of the present embodiment. 1A is a plan view seen from the lid (lid) side, FIG. 1B is a cross-sectional view taken along the line AA in FIG. 1A, and FIG. 1C is FIG. It is sectional drawing in the BB line of (a). In the plan view, the lid is omitted for convenience.

As shown in FIG. 1, the crystal resonator 1 includes a crystal vibrating piece 10 as a piezoelectric vibrating piece and a package 20 as an external member that supports and accommodates the crystal vibrating piece 10.
The quartz crystal resonator element 10 has a wafer-like quartz substrate cut out from a quartz crystal or the like at a predetermined angle as a base material, and has an outer shape formed by wet etching using a photolithography technique.
The quartz crystal resonator element 10 includes a base portion 11, a pair of vibrating arms 12 that extend substantially in parallel with each other from one end of the base portion 11, and the other end that is opposite to the one end side of the base portion 11 in the extending direction of the pair of vibrating arms 12. And a holding portion 13 connected to the side.

The other end side of the base portion 11 of the quartz crystal vibrating piece 10 was cut out from both sides along a direction (here, a substantially orthogonal direction) intersecting the extending direction (longitudinal direction) of the pair of vibrating arms 12. A pair of notch parts (constriction part) 14 is formed.
The pair of resonating arms 12 of the quartz crystal resonator element 10 includes an arm portion 15 positioned on the base 11 side, a weight portion 16 positioned on the distal end side of the arm portion 15 and wider than the arm portion 15, and both main surfaces (crystal And a longitudinal direction of the pair of vibrating arms 12 formed along at least one (here, both) of the vibrating arms 12 extending in the longitudinal direction. And a groove portion 19 having a substantially H-shaped cross-sectional shape cut along a plane orthogonal thereto.

Here, the quartz crystal vibrating piece 10 is a tuning fork type quartz vibrating piece that includes a pair (two) of vibrating arms 12 and a base portion 11 and constitutes a tuning fork.
When it is necessary to describe the pair of vibrating arms 12 individually, one (upper side of the drawing) is the vibrating arm 12a and the other (lower side of the drawing) is the vibrating arm 12b.

  The holding portion 13 of the quartz crystal vibrating piece 10 is formed from the holding portion base portion (the portion extending in the direction substantially orthogonal to the longitudinal direction of the pair of vibrating arms 12 from the other end side of the base portion 11) of the vibrating arm 12a. A first arm portion 13a extending to the vicinity of the tip of the weight portion 16 along one side (upper side of the paper surface) and a second arm extending along the other side (lower side of the paper surface) of the vibrating arm 12b and shorter than the first arm portion 13a. 2 arms 13b.

The holding portion 13 is provided with support portions 13c, 13d, and 13e supported by the package 20 on the distal end side and the root side of the first arm portion 13a and the second arm portion 13b.
More specifically, the holding portion 13 is provided with a support portion 13c near the tip of the first arm portion 13a and in the vicinity of the connection portion between the arm portion 15 of the vibrating arm 12a and the weight portion 16, and the first arm portion 13a. A support portion 13d is provided at a position closer to the root, and a support portion 13e is provided at the tip of the second arm portion 13b.
In addition, the part in which each support part 13c, 13d, 13e of the 1st arm part 13a and the 2nd arm part 13b is provided is formed more widely than the part by the side of a base in order to ensure sufficient support area.

The quartz crystal resonator element 10 has a crystal oscillation in a region (in a substantially triangular range surrounded by a two-dot chain line in FIG. 1A) connecting the outer circumferences of the support portions 13c, 13d, and 13e in plan view. It is formed so that the center of gravity G of the piece 10 is located.
The crystal vibrating piece 10 has a distance L1 from the root of the first arm portion 13a to the support portion 13d on the root side of the first arm portion 13a so that the support portion of the second arm portion 13b extends from the root of the second arm portion 13b. It is configured to be longer than the distance L2 up to 13e.

The package 20 includes a package base 21 having a recess that supports and accommodates the crystal resonator element 10 therein, a lid 22 that covers the recess of the package base 21, a bonding material 23 that hermetically bonds the package base 21 and the lid 22, and It has.
The package base 21 is made of an aluminum oxide sintered body obtained by forming, laminating and firing ceramic green sheets.
The lid 22 is made of a metal such as Kovar, 42 alloy, stainless steel, glass, ceramic, or the like.
For the bonding material 23, when the lid 22 is a metal, a brazing material such as a seam ring made of Kovar, silver brazing, solder, gold / tin alloy is used, and when the lid 22 is glass, ceramic or the like, a low melting point glass is used. Adhesives are used.

On the inner bottom surface (inner bottom surface) 24 of the package base 21, internal electrodes 24 c that support the support portions 13 c, 13 d, and 13 e at positions facing the support portions 13 c, 13 d, and 13 e of the quartz crystal vibrating piece 10, 24d and 24e are formed.
Specifically, on the inner bottom surface 24, an internal electrode 24c is formed at a position facing the support portion 13c of the quartz crystal vibrating piece 10, an internal electrode 24d is formed at a position facing the support portion 13d, and faces the support portion 13e. The internal electrode 24e is formed at the position where
The planar shape of each internal electrode 24c, 24d, 24e is not particularly limited, such as a circle, an ellipse, a rectangle, or a polygon. Further, the internal electrodes 24c and 24d may be connected to each other by a conductor wired on the surface of the inner bottom surface 24 of the package base 21 to form an integrated electrode.

A pair of external terminals 26 are formed in a substantially rectangular shape on the outer bottom surface (outer bottom surface) 25 of the package base 21.
One of the pair of external terminals 26 is connected to the internal electrode 24d by an internal wiring (not shown), and the other is connected to the internal electrode 24e.
The internal electrode 24c may not be connected to the external terminal 26.
Each of the internal electrodes 24c, 24d, 24e and the pair of external terminals 26 is made of a metal film in which a film of nickel, gold or the like is laminated on a metallized layer of tungsten or the like by plating.

  The package base 21 is in a position that does not overlap with the quartz crystal vibrating piece 10 in a plan view, the other side of the vibrating arm 12b (the lower side in the drawing), the tip of the second arm portion 13b, and the package base 21 In a space surrounded by the lower surface of the paper and the inner wall on the right side of the paper surface, a buffer portion 21a that protrudes from the inner wall of the package base 21 on the lower surface of the paper surface toward the vibrating arm 12b is disposed.

The buffer portion 21a is set so that the height from the inner bottom surface 24 is equal to or higher than the height of the main surface 17 of the vibrating arm 12b (in the sectional view, the height of the buffer portion 21a is equal to or higher than the height of the vibrating arm 12b. To be formed.
The buffer portion 21a is formed such that the distance between the vibrating arm 12b and the weight portion 16 in plan view increases as it goes toward the tip of the vibrating arm 12b. In other words, the contour line facing the weight portion 16 in the buffer portion 21a is inclined downward to the right with respect to the horizontal contour line of the weight portion 16 on the paper surface.

  The quartz resonator 1 is configured so that the weight portions 16 of the pair of vibrating arms 12 are displaced in a plan view (for example, the side surface in the longitudinal direction of the package 20) exceeding a predetermined displacement amount (for example, the maximum amplitude during normal vibration). When an impact is applied from the outside, such as a drop that becomes a collision surface), one side (the upper side of the paper surface) contacts (collises) the tip portion 13f of the first arm portion 13a of the holding portion 13 and the other side On the side (the lower side in the drawing), the interval between the weight portion 16, the first arm portion 13a, and the buffer portion 21a is set so as to contact (collision) with the buffer portion 21a.

More specifically, in the crystal resonator 1, the interval W1 between the tip portion 13f of the first arm portion 13a of the holding portion 13 and the weight portion 16 of the vibrating arm 12a is set so that the weight portion 16 is predetermined on one side (upper side of the paper surface). The distance is set such that the side surface of the weight portion 16 comes into contact with the side surface of the distal end portion 13f of the first arm portion 13a when the displacement exceeds the above displacement amount.
Then, when the interval W2 between the buffer portion 21a and the weight portion 16 of the vibrating arm 12b is displaced to the other side (the lower side of the drawing surface) by the weight portion 16 exceeding the predetermined displacement amount, The distance at which the side surface of the weight portion 16 contacts the side surface of the buffer portion 21a is set.

At this time, as described above, the crystal unit 1 is formed so that the distance between the buffer portion 21a and the weight portion 16 becomes wider toward the tip of the vibrating arm 12b. As shown by a two-dot chain line in a), the displaced side surface of the weight portion 16 'can be brought into surface contact with the side surface of the buffer portion 21a.
Further, the buffer portion 21 a is packaged from the weight portion 16 at a position closer to the arm portion 15 than the distal end portion of the weight portion 16 so that the distal end portion of the weight portion 16 is not damaged during surface contact with the weight portion 16. It is preferably formed so as to be away from the inner wall side of the base 21.
In addition, in order to avoid easily the damage at the time of the contact with the weight part 16, the corner | angular part by the side of the weight part 16 of the front-end | tip part 13f of the 1st arm part 13a is preferably rounded circularly.

Incidentally, the package base 21 is provided with a sealing portion 27 for sealing the inside of the package 20 in the buffer portion 21a.
The sealing portion 27 has a spherical shape made of gold / germanium alloy, solder, or the like in a through hole (a stepped through hole having a larger hole diameter on the outer bottom surface 25 side than a hole diameter on the inner bottom surface 24 side) formed in the package base 21. The inside of the package 20 is hermetically sealed by charging the sealing material 29, curing after heating and melting.

The quartz crystal vibrating piece 10 is supported by each support portion 13c of the holding portion 13 via a conductive adhesive 30 such as an epoxy type, bismaleimide type, silicone type, or polyimide type mixed with a conductive material such as a metal filler. 13d and 13e are joined to the internal electrodes 24c, 24d and 24e of the package base 21, respectively.
Thereby, in the quartz crystal vibrating piece 10, an excitation electrode (not shown) is electrically connected to the external terminal 26 via the internal electrodes 24 d and 24 e.

The support portion 13c facing the internal electrode 24c that is not electrically connected to the external terminal 26 may be supported by the internal electrode 24c but not joined.
In this case, the thickness of the internal electrode 24c may be corrected (thickened) in consideration of the thickness of the conductive adhesive 30 to avoid an inclination when the crystal vibrating piece 10 is joined.
Further, the internal electrode 24c and the internal electrode 24d may be connected by the outflow of the conductive adhesive 30 or the like.
In addition, as described above, the quartz vibrating piece 10 may be fixed by applying the conductive adhesive 30 to two places on the electrode having a configuration in which the internal electrode 24c and the internal electrode 24d are integrated. The conductive adhesive 30 applied to the substrate may flow out after application and bond to each other.
In other words, the crystal vibrating piece 10 may be fixed to the package base 21 via the conductive adhesive 30 applied so as to straddle between the support portion 13c and the support portion 13d.

In the crystal resonator 1, the crystal vibrating piece 10 is bonded to the internal electrodes 24 c, 24 d, 24 e of the package base 21, and then the lid 22 is bonded to the package base 21 via the bonding material 23.
In plan view, if each corner of the inner wall of the package base 21 is formed in an arc shape (corner radius portion), each corner portion of the crystal vibrating piece 10 facing the corner radius portion is in an arc shape. It is preferably rounded.

Such a configuration is effective for preventing damage to the crystal resonator element 10 when the crystal resonator element 10 is mounted on the package 20.
That is, in the crystal resonator 1, for example, when each corner of the inner wall of the package base 21 is formed in an arc shape in consideration of an improvement in stress resistance performance, the corner portion has a crystal vibration compared to a shape having a 90 ° corner. The position is close to the piece 10.
On the other hand, in the crystal resonator 1, the crystal resonator element 10 that is formed in an arc shape compared with the corner portion of the crystal resonator element 10 having an acute angle of 90 ° or less has a corner on the inner wall of the package base 21. The distance from the corner of the crystal vibrating piece 10 can be increased.

From such a relationship, in the crystal resonator 1, even if each corner of the inner wall of the package base 21 has an arc shape, if the corner portion of the crystal resonator element 10 has an arc shape, the distance between the two is determined by the crystal resonator element 10. It is possible to make the corners wider than when the corners are acute.
Therefore, when the crystal resonator element 1 is mounted on the package 20 when the corners of the inner wall of the package base 21 and the corner portions of the crystal resonator element 10 are both arcuate, Even if some deviation occurs, it is possible to make it difficult for the quartz crystal vibrating piece 10 and the package 20 to contact each other.

  In the crystal unit 1, after the lid 22 is joined, the sealing material 29 is filled in the through hole 28 of the sealing portion 27 in a state where the inside of the package 20 is decompressed (high vacuum state). The inside is hermetically sealed.

The crystal resonator 1 is applied with a drive signal from the outside via a pair of external terminals 26, internal electrodes 24d and 24e, a conductive adhesive 30, and an excitation electrode. The vibrating arm 12 bends and vibrates in the direction of arrow C at a predetermined frequency (for example, 32 kHz).
At this time, since the quartz resonator 1 is in a state where the inside of the package 20 is decompressed (a state with a high degree of vacuum), the bending vibration of the quartz crystal resonator element 10 is less likely to be inhibited compared to the case where the decompression is not performed. Therefore, it is possible to obtain a stable bending vibration.

As described above, the crystal resonator 1 according to this embodiment includes the support portions 13c and 13d on the distal end side and the root side of the first arm portion 13a of the holding portion 13 of the crystal vibrating piece 10 and the second arm portion 13b. 13e are provided, and the center of gravity G of the quartz crystal vibrating piece 10 is located in a region connecting the outer circumferences of the support portions 13c, 13d, and 13e in plan view.
As a result, when the crystal vibrating piece 10 is supported by the package 20, inclination due to its own weight is avoided, so that the parallelism with the inner bottom surface 24 of the package base 21 that is the support surface of the package 20 is maintained. Thus, it can be joined to the package 20.
As a result, the quartz crystal resonator 1 has a conventional configuration in which the gap L3 (see FIG. 1B) between the quartz crystal vibrating piece 10 and the inner bottom surface 24 of the package base 21 is likely to be inclined due to its own weight (the center of gravity G is supported by each). The configuration can be set to be less than the configuration in which the outer circumferences of the portions 13c, 13d, and 13e are connected to each other, so that the total thickness can be reduced.
In addition, since the crystal resonator element 1 can hold the crystal resonator element 10 in parallel with the inner bottom surface 24 of the package base 21, the productivity when the crystal resonator element 10 is bonded to the package 20 can be improved.

  Since the crystal vibrating piece 10 of the type having the groove portion 19 and the weight portion 16 in the vibrating arm 12 has a tendency that the center of gravity G is located closer to the tip of the vibrating arm 12, the parallelism with the inner bottom surface 24 of the package base 21. In order to be bonded to the package 20 while maintaining the above, this configuration is extremely effective.

Further, the quartz crystal resonator element 10 has a distance L1 from the root of the first arm portion 13a of the holding portion 13 to the support portion 13d on the root side of the first arm portion 13a, and the second arm portion from the root of the second arm portion 13b. It is comprised so that it may become longer than the distance L2 to the support part 13e of 13b.
As a result, the quartz crystal resonator element 10 is less likely to resonate between the first arm portion 13a and the second arm portion 13b during normal vibration of the vibrating arm 12 or during an external impact such as dropping. For example, it is possible to improve vibration characteristics such as frequency stability.
Further, since the distance L1 is longer than the distance L2, the crystal resonator 1 is configured to bond the support portion 13d on the base side of the first arm portion 13a of the crystal vibrating piece 10 to the package 20 with the conductive adhesive 30. Adhesion of the conductive adhesive 30 to the base portion 11 can be reduced as compared with the case where the support portion 13e of the second arm portion 13b is joined to the package 20.

  Further, when the support portion 13c of the crystal resonator element 10 is supported by the internal electrode 24c but not joined, the crystal resonator 1 reduces the inhibition of the bending vibration of the crystal resonator element 10 caused by the support portion 13c. it can.

  Further, the crystal resonator 1 is a tuning fork type crystal vibrating piece in which excellent vibration characteristics can be easily obtained by forming a tuning fork by including a pair (two) of vibrating arms 12 and a base portion 11. Therefore, vibration characteristics can be improved.

Further, when the weight portion 16 of the vibrating arm 12 is displaced beyond a predetermined displacement amount, the quartz crystal resonator 1 contacts the tip portion 13f of the first arm portion 13a on one side (the upper side in the drawing) of the vibrating arm 12a. The intervals W1 and W2 are set so that the other side of the vibrating arm 12b (the lower side in the drawing) is in surface contact with the buffer portion 21a of the package base 21.
Therefore, in the crystal resonator 1, the impact force applied to the weight portion 16 of the vibrating arm 12 at the time of impact such as dropping is alleviated by the bending of the tip portion 13f of the first arm portion 13a on one side of the vibrating arm 12a. Then, the other side of the vibrating arm 12b is dispersed by surface contact with the buffer portion 21a of the package base 21, and damage to the weight portion 16 (vibrating arm 12) can be reduced.

At this time, when the support portion 13c of the first arm portion 13a is only supported without being joined to the internal electrode 24c by the conductive adhesive 30, the tip portion 13f of the first arm portion 13a is more easily bent. Thus, the impact force applied to the weight portion 16 of the vibrating arm 12a is further alleviated.
The quartz crystal resonator element 10 has a configuration in which the weight portion 16 is in contact with the first arm portion 13a and the buffer portion 21a because the weight portion 16 is stronger than the arm portion 15 having the groove portion 19. .

Moreover, since the sealing part 27 is provided in the buffer part 21a, the quartz resonator 1 can aim at the efficient utilization of the space of the package 20. FIG.
As a result, the crystal unit 1 can suppress an increase in the planar size due to the arrangement of the sealing portion 27.

Further, in the crystal resonator 1, each corner portion of the quartz crystal resonator element 10 facing each corner radius portion of the inner wall of the package base 21 in a plan view is rounded into an arc shape. Damage due to contact between the quartz vibrating piece 10 and the quartz vibrating piece 10 can be reduced.
In addition, the crystal resonator 1 can reduce damage to the crystal resonator element 10 during transportation or the like by the above configuration even in a wafer state before the crystal resonator element 10 is singulated.

In addition, since the quartz vibrating piece 10 is provided with the weight portion 16 on the vibrating arm 12, the Q value (a dimensionless number representing the state of vibration) due to the increase of the inertial mass of the weight portion 16, For example, the vibration arm 12 can be shortened while maintaining the Q value.
As a result, the crystal resonator 1 can be further reduced in size while maintaining the Q value of the crystal resonator element 10.

On the other hand, when the quartz crystal vibrating piece 10 has the weight portion 16, for example, distortion in flexural vibration becomes larger than when the weight portion 16 is not present (generated compressive stress and tensile stress are increased).
However, since the crystal vibrating piece 10 has the groove portion 19 in the vibrating arm 12, it is possible to delay the equilibrium (thermal conduction) of the thermal gradient generated by the distortion in the bending vibration. Loss of vibration energy caused by heat conduction generated between the compression part and the extension part of the vibrating piece that vibrates can be suppressed.

  Further, the crystal vibrating piece 10 has a notch portion 14 formed in the base portion 11 and a holding portion 13 connected to the base portion 11, so that vibration leakage to the outside due to bending vibration of the vibrating arm 12 is prevented. Can be reduced.

In the above embodiment, the support portion 13c and the internal electrode 24c do not have to be joined. However, the present invention is not limited to this, and the support portion 13c and the internal electrode 24c are joined and the support portion 13d. And the internal electrode 24d may not be joined. In this case, the connection with the external terminal 26 is also changed.
In the crystal resonator element 10, each corner portion facing each corner radius portion of the inner wall of the package base 21 may not be rounded.

Here, the modification of the said embodiment is demonstrated.
(Modification 1)
FIG. 2 is a schematic diagram showing a schematic configuration of the crystal resonator of the first modification. 2A is a plan view seen from the lid side, FIG. 2B is a cross-sectional view taken along the line DD in FIG. 2A, and FIG. 2C is a cross-sectional view of FIG. It is sectional drawing in the EE line | wire. In the plan view, the lid is omitted for convenience. Moreover, about the common part with the said embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted and it demonstrates centering on a different part from the said embodiment.

As shown in FIG. 2, in the crystal resonator 2, the pair of vibrating arms 12 of the crystal vibrating piece 110 has a first arm portion 113 a that is intermediate between the first arm portion 113 a and the second arm portion 13 b of the holding portion 113. It is arranged closer.
In other words, in the crystal resonator 2, the pair of vibrating arms 12 of the quartz crystal vibrating piece 110 has an interval W3 between the vibrating arm 12a and the first arm portion 113a, and an interval W4 between the vibrating arm 12b and the second arm portion 13b. It arrange | positions so that it may become narrower.

Here, the center line CL1 in the width direction (up and down direction in the drawing) of the pair of vibrating arms 12 and the middle between the first arm portion 113a and the second arm portion 13b of the holding portion 113, that is, the width direction of the holding portion 113 (in the drawing surface). The offset amount (shift amount) OS with respect to the center line CL2 in the vertical direction is preferably within 10% of the width W5 of the holding portion 113.
This numerical value is derived based on knowledge obtained from the inventors' experimental results and simulation analysis results.
As an example, the crystal vibrating piece 110 has a total length of about 1.5 mm and a total width (W5) of about 0.6 mm.

Further, with the movement of the pair of vibrating arms 12, the crystal resonator 2 has a shorter first arm portion 113a in order to avoid interference between the first arm portion 113a and the weight portion 16 of the vibrating arm 12a. Is formed.
Specifically, the first arm portion 113a is formed to have a length such that the tip portion 113f is located in the vicinity of the connection portion between the arm portion 15 and the weight portion 16 of the vibrating arm 12a.
And the support part 113c of the front end side of the 1st arm part 113a is provided in the front-end | tip part 113f.
If the offset amount OS is small and interference between the first arm portion 113a and the weight portion 16 of the vibrating arm 12a can be avoided, the length of the first arm portion 113a need not be changed.

  In the crystal resonator 2, the vibration of the buffer portion 121a is maintained in order to maintain the distance W2 between the buffer portion 121a and the weight portion 16 of the vibrating arm 12b by the amount of movement of the pair of vibrating arms 12 closer to the first arm portion 113a. The amount of protrusion toward the arm 12b increases.

As described above, in the crystal resonator 2, the pair of vibrating arms 12 is disposed closer to the first arm portion 113 a than the middle between the first arm portion 113 a and the second arm portion 13 b of the holding portion 113. The center of gravity G of the quartz crystal vibrating piece 110 is closer to the first arm portion 113a, and it becomes easy to position the center of gravity G of the quartz crystal vibrating piece 110 in a region connecting the outer circumferences of the support portions 113c, 13d, and 13e.
In addition, the said structure is applicable also to the following modification 2.

(Modification 2)
FIG. 3 is a schematic plan view showing a schematic configuration of the crystal resonator of the second modification. In FIG. 3, the lid is omitted for convenience. Moreover, about the common part with the said embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted and it demonstrates centering on a different part from the said embodiment.

As shown in FIG. 3, the quartz resonator 3 has a width W6 of a portion including the support portion 213c on the distal end side of the first arm portion 213a and the support portion 213d on the root side in the holding portion 213 of the quartz crystal vibrating piece 210. It is formed wider than the width W7 of the portion including the support portion 13e of the two arm portions 13b.
Note that the portion of the first arm portion 213a from the support portion 213c (on the tip portion 13f side) may remain thin.

According to this, in the crystal resonator 3, the width W6 of the portion including the support portions 213c and 213d of the first arm portion 213a in the holding portion 213 of the crystal vibrating piece 210 is different from the support portion 13e of the second arm portion 13b. Since the included portion is wider than the width W7, the mass of the first arm portion 213a is increased and the center of gravity G of the quartz crystal vibrating piece 210 is closer to the first arm portion 213a than in the above embodiment.
As a result, the quartz crystal resonator 3 can easily position the center of gravity G of the quartz crystal vibrating piece 210 within a region connecting the outer circumferences of the support portions 213c, 213d, and 13e of the quartz crystal vibrating piece 210.

Further, in the crystal resonator 3, the width W6 of the portion including the support portions 213c and 213d of the first arm portion 213a in the holding portion 213 of the crystal vibrating piece 210 is widened. The support portions 213c and 213d can be enlarged.
As a result, the quartz crystal resonator 3 can more reliably support the quartz crystal vibrating piece 210 by the internal electrodes 24c, 24d, and 24e of the package base 21.
The above configuration can also be applied to the first modification.

In the above-described embodiment and each modification, the number of support portions (13c, etc.) of the quartz crystal vibrating piece (10, etc.) is three. However, the present invention is not limited to this. Four or more may be provided.
Moreover, in the said embodiment and each modification, although the number of the vibrating arms 12 of the quartz crystal vibrating piece (10 etc.) was two, it is not limited to this, One or three or more may be sufficient.

In the above-described embodiment and each modification, the piezoelectric vibrating piece is made of quartz, but is not limited to this. For example, lithium tantalate (LiTaO ₃ ), lithium tetraborate (Li ₂ B ₄ O ₇ ) , Piezoelectric materials such as lithium niobate (LiNbO ₃ ), lead zirconate titanate (PZT), zinc oxide (ZnO), and aluminum nitride (AlN), or piezoelectric materials such as zinc oxide (ZnO) and aluminum nitride (AlN) It may be silicon or the like provided with a coating.

  1, 2, 3... Crystal resonator as a piezoelectric device, 10... Crystal vibrating piece as a piezoelectric vibrating piece, 11... Base, 12, 12a, 12b... Vibrating arm, 13. 13b ... second arm, 13c, 13d, 13e ... support, 13f ... tip, 14 ... notch, 15 ... arm, 16 ... weight, 17, 18 ... main surface, 19 ... groove, 20 ... Package as an external member, 21 ... Package base, 21a ... Buffer portion, 22 ... Lid, 23 ... Joint material, 24 ... Inner bottom surface, 24c, 24d, 24e ... Internal electrode, 25 ... Outer bottom surface, 26 ... External terminal, 27 DESCRIPTION OF SYMBOLS ... Sealing part, 28 ... Through-hole, 29 ... Sealing material, 30 ... Conductive adhesive agent, 110 ... Quartz vibrating piece, 113 ... Holding part, 113a ... First arm part, 113c ... Supporting part, 113f ... Tip part , 210... Crystal vibrating piece, 213... Holding part, 21 a ... first arm part, 213c, 213d ... support part, CL1 ... center line of a pair of vibrating arms, CL2 ... center line of holding part, G ... center of gravity, L1, L2 ... distance, L3 ... gap, OS ... offset amount , W1, W2, W3, W4... Spacing between each component, W5, W6, W7... Width of each component.

Claims (8)

The base,
A vibrating portion comprising a vibrating arm extending along a first direction from one end of the base;
A first arm connected to the other end of the base opposite to the one end , and extending along the first direction; and along the first direction. A second arm portion that is extended and shorter in length than the first arm portion, and is arranged so that the vibrating portion is located between the first arm portion and the second arm portion in plan view; A holding part,
Including
The first arm portion includes a first support portion, and a second support portion that is disposed on a proximal end side with respect to the first support portion,
The second arm portion includes a third support portion,
The distance from the base end of the first arm part to the second support part is longer than the distance from the base end of the second arm part to the third support part,
The center of gravity of the system including the base, the vibrating part, and the holding part is
In the planar view, the resonator element is located within a region surrounded by an imaginary line connecting the first support portion, the second support portion, and the third support portion. In claim 1 ,
The center of the vibration part is arranged closer to the first arm part than the middle between the first arm part and the second arm part in the plan view. In claim 1 or 2 ,
Where the first arm portion of the first support portion is disposed above the place is the first second direction along the width intersecting the direction in which and the second supporting portion is arranged resonator element said second width along the direction, and wherein the wider than the second arm portion of the third support portion along said second direction where is located the width. In any one of Claims 1 thru | or 3 ,
The vibrating piece includes a plurality of vibrating arms. In any one of Claims 1 thru | or 4 ,
The vibrating arm is
A resonator element comprising a groove portion provided along at least one of the first main surface and the second main surface in a front-back relationship along the first direction. In any one of Claims 1 thru | or 5 ,
The vibrating arm is
An arm portion disposed on the one end side of the base portion;
A weight portion connected to a tip side of the arm portion in the first direction and having a width wider than the arm portion;
A vibrating piece comprising: In any one of Claims 1 thru | or 6 ,
The base is provided with a notch that is disposed between the one end and the other end and is notched along a second direction that intersects the first direction. A vibrating piece characterized by having The resonator element according to any one of claims 1 to 7 ,
A package containing the resonator element;
With
The vibration device, wherein the first support portion, the second support portion, and the third support portion are supported by the package.

Images