JP2011015101A - Flexural-mode tuning-fork type crystal vibrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the propagation of vibration to a supporting part.SOLUTION: A flexural-mode tuning-fork type crystal vibrator includes a base, a pair of vibrating arms extending from the base, and a pair of support arms extending from the base along the vibrating arms where the vibrating arms extend from the base inside the support arms provided in the pair, and the support arms have first concave portions in groove shapes to the overall width in the width direction. The support arms may be provided having the first concave portions at both principal surfaces of the vibrating arms at a predetermined interval without facing each other.

Description

  The present invention relates to a tuning fork-type bent quartz crystal resonator used in electronic equipment.

Conventionally, a piezoelectric vibrator or a piezoelectric oscillator is mounted as an electronic component in an electronic device such as a computer, a mobile phone, or a small information device. This piezoelectric vibrator or piezoelectric oscillator is used as a reference signal source or a clock signal source. In addition, the piezoelectric vibrator and the piezoelectric oscillator have a tuning fork-type bent quartz crystal made of quartz inside.
Hereinafter, a tuning fork-type bending quartz crystal resonator using quartz as a piezoelectric material will be described.

FIG. 11 is a perspective view showing an example of a conventional tuning-fork type bent crystal resonator. FIG. 12 is a perspective view showing an example of a piezoelectric piece used in a conventional tuning fork-type bent crystal resonator.
As shown in FIG. 11, the tuning-fork type bending crystal resonator 400 includes a piezoelectric piece 410 (see FIG. 12), excitation electrodes 421a, 421b, 422a and 422b provided on the surface of the piezoelectric piece 410, and a connection piece. The electrodes 423a and 423b, frequency adjusting metal films 424a and 424b, and conductive wiring patterns 425, 426, and 427 are roughly configured (see, for example, Patent Document 1).

As shown in FIG. 12, the piezoelectric piece 410 has a base portion 411 that is a substantially rectangular flat plate in plan view, a vibrating arm portion 412 that extends from one side of the base portion 411 in the same direction, and further extends from the base portion 411. It is comprised by the support arm part 414 (for example, refer patent document 1).
Hereinafter, since the vibrating arm portion 412 is configured as a pair of two, it will be described as a first vibrating arm portion 412a and a second vibrating arm portion 412b.
The support arm portion 413 is located between the first vibrating arm portion 412a and the second vibrating arm portion 412b. From this position, the first vibrating arm portion 412a and the second vibrating arm portion 412b are connected to the base portion 411. It extends in the same direction.

  The piezoelectric piece 410 includes a base portion 411, a first vibrating arm portion 412a, a second vibrating arm portion 412b, and a supporting arm portion 413 (see, for example, Patent Document 1).

  As shown in FIG. 11, the excitation electrode 421 a is provided on the front and back main surfaces of the first vibrating arm portion 412 a constituting the piezoelectric piece 410 that face each other. The front and back main surfaces are the surfaces formed with the largest surface area of the base part 411, and are two surfaces in which one surface and the other surface are parallel to each other. The surface facing the same direction is also included. 11 and 12, the surface appearing in the drawings is referred to as “front surface”, and the hidden surface is referred to as “back surface”.

  The excitation electrode 421b is provided on both opposing side surfaces of the first vibrating arm portion 412a. Further, the excitation electrode 422a is provided on the front and back main surfaces of the second vibrating arm portion 412b facing each other. Further, the excitation electrode 422b is provided on both opposite side surfaces of the second vibrating arm portion 412b.

Note that the excitation electrodes 421b provided on both side surfaces of the first vibrating arm portion 412a are electrically connected by a frequency adjusting metal film 424a.
Further, the excitation electrodes 422b provided on both side surfaces of the second vibrating arm portion 412b are electrically connected by the frequency adjusting metal film 424b.

The connection electrodes 423a are provided on the front and back main surfaces of the support arm portion 413, one pair at a time and opposed to each other between the main surfaces. The connection electrode 423a is electrically connected to a portion provided on the other main surface of the support arm portion 413. The connection electrode 423a is also electrically connected to the excitation electrode 421b.
The connection electrode 423a is electrically connected to the excitation electrode 422a of the second vibrating arm portion 412b by a conductive wiring pattern 427 provided on the main surface of the base portion 411.

Further, the connection electrodes 423b are provided on the entire front and back main surfaces of the support arm portion 413, one by one, at a position facing each other between the main surfaces. The connection electrode 423b is electrically connected to a portion provided on the other main surface of the support arm portion 413. The connection electrode 423b is also electrically connected to the excitation electrode 422b.
The connection electrode 423b is electrically connected to the excitation electrode 421a through a conductive wiring pattern provided on the main surface of the base 411.

  Note that the connection electrodes 423a and 423b are provided on the front and back main surfaces of the support arm portion 413 so as not to be electrically connected to each other.

The frequency adjusting metal film 424a is provided on the front main surface and the front end of the side surface of the first vibrating arm portion 412a, and is electrically connected to the excitation electrode 421b provided on both side surfaces of the first vibrating arm portion 412a. Connected. The frequency adjusting metal film 424b is provided on the front main surface and the front end of the side surface of the second vibrating arm portion 412b, and the excitation electrode 422b provided on both side surfaces of the second vibrating arm portion 412b. And is electrically connected.
Note that the piezoelectric vibration element 400 can adjust the vibration frequency value to a desired value by increasing or decreasing the amount of the metal constituting the frequency adjusting metal films 424a and 424b.

By the way, the tuning fork type bending crystal resonator has a structure in which vibration leaking from the vibrating arm portion is absorbed by a pair of supporting arm portions extending from both sides of the base portion (see, for example, Patent Document 2). .
Further, as an application mode of the tuning fork-type bent quartz crystal resonator disclosed in Patent Document 2, a notch is provided in the thickness direction of the support arm portion, and the vibration leaking from the vibrating arm portion is attenuated by the notch. The vibration is prevented from propagating (see, for example, Patent Document 3).
Further, as a structure of a tuning fork-type bent crystal resonator, a structure in which a groove-like recess is formed on the main surface of the base has been proposed. This tuning fork type vibration element has a groove-like recess formed so as to attenuate the vibration leaking from the vibrating arm portion and prevent the propagation of vibration (see, for example, Patent Document 4).

Note that these tuning fork-type bent quartz crystal resonators are mounted on, for example, an element connection electrode pad formed on the bottom surface of the recess of an element mounting member having a recess having an opening on one main surface. The opening is hermetically sealed with a lid to form a piezoelectric vibrator (see, for example, Patent Document 5).
In addition, these tuning-fork type bent quartz resonators are mounted on, for example, an element connection electrode pad formed on the bottom surface of the recess of an element mounting member having a recess having an opening on one main surface, The opening is hermetically sealed with a lid, and at least an integrated circuit element including an oscillation circuit is electrically connected to the piezoelectric vibration element to form a piezoelectric oscillator (see, for example, Patent Document 5).

JP 2006-345519 A JP 2005-094724 A JP 2006-148857 A Japanese Utility Model Publication No. 51-138076 JP 2008-252800 A

However, as the tuning fork type bent quartz crystal unit becomes smaller, the outer shape of the element is relied on chemical etching. However, in the chemical etching, the thickness direction of the tuning fork type bent crystal unit provided on the support arm portion is relied on. Since a residue is generated in the notch, it is difficult to form into an accurate shape. Due to such a residue, the vibration is not sufficiently attenuated by the notch and is propagated to the portion where the vibration is supported, and the value of the frequency deviation at a predetermined temperature (hereinafter referred to as “temperature characteristic”) is deteriorated. In addition, the value of crystal impedance (hereinafter sometimes referred to as “CI value”) may be deteriorated.
In addition, the tuning fork-type bending quartz crystal whose supporting arm part is not a part of the constituent element has a groove-like recess in the width direction of the base part, that is, in the direction perpendicular to the direction in which the vibrating arm part extends from the base part. Even if formed, the vibration leaking from the vibrating arm portion cannot be sufficiently attenuated, and the temperature characteristics and the CI value may be deteriorated.

  Accordingly, an object of the present invention is to provide a tuning fork-type bent quartz crystal resonator that solves the above-described problems, attenuates vibration from the vibrating arm portion, and reduces propagation of vibration.

  In order to solve the above-mentioned problem, the present invention includes a base, a pair of vibrating arms extending from the base, and a single supporting arm extending from the base along the vibrating arms. The support arm portion has a groove-shaped first recess across the entire width in the width direction, and the support arm portion is provided between the vibrating arm portions provided in pairs. The tuning-fork type bending crystal resonator.

  Further, the present invention may be configured such that the support arm portion is provided with a predetermined interval without facing each other while having the first concave portion on both main surfaces of the vibrating arm portion.

  In the present invention, the support arm portion may be configured to extend in a direction opposite to the vibrating arm portion extending from the base portion.

  Moreover, the present invention may be configured such that the base portion has a groove-shaped second recess in a direction perpendicular to the extending direction of the vibrating arm portion.

  Further, in the present invention, the base portion may be provided at a predetermined interval without facing each other while having the second concave portion on both main surfaces of the base portion.

  In the present invention, each of the pair of vibrating arm portions may have a groove-shaped third recess that is shorter than the vibrating arm portion.

  In addition, the present invention may be configured such that each of the pair of vibrating arm portions has a groove-shaped third concave portion in which two or more shorter than the vibrating arm portion are arranged.

  According to such a tuning fork type bent quartz crystal resonator, the support arm portion extending from the base portion has the groove-shaped first concave portion in the width direction thereof, so that the first concave portion is formed by chemical etching. Even if formed, the change in shape due to the residue can be reduced. In addition, since the support arm portion extending from the base portion has a groove-shaped first recess in the width direction, vibration leaking from the vibrating arm portion reaches the first recess of the support arm portion. Since the vibration is further attenuated by the first recess after being attenuated by the base or the supporting arm partway, it is possible to reduce the propagation of vibration to the supporting part and prevent deterioration of temperature characteristics and CI value. it can.

  Further, according to the present invention, since the support arm portion has the first recess on the front and back main surfaces of the vibrating arm portion and is provided at a predetermined interval without facing each other, the front main surface side The vibration propagating on the back main surface side can be attenuated while the vibration propagating through is attenuated.

  Further, the present invention is configured such that the support arm portion extends in a direction opposite to the vibrating arm portion extending from the base portion, and vibration leaking from the vibrating arm portion is attenuated by the first recess portion of the support arm portion. Can be made.

  In the present invention, since the second concave portion is provided in the width direction of the base portion, the vibration is attenuated by the first concave portion of the support arm portion and the vibration is attenuated by the second concave portion of the base portion. Damping of vibration leaking from the arm portion can be further improved.

  In the present invention, the second recesses on the front and back main surfaces of the base are provided at predetermined intervals without facing each other. Vibrations propagating on the surface side can be attenuated.

  Further, in the present invention, each of the pair of vibrating arms has a structure having a groove-shaped third recess that is shorter than the vibrating arm portion, and the supporting arm portion has vibration leaking from the vibrating arm portion. It can be attenuated at the first recess.

  Further, the present invention has a structure in which each of the pair of vibrating arms has a groove-shaped third concave portion arranged in two or more shorter than the vibrating arm portion, and vibration leaks from the vibrating arm portion. Can be attenuated by the first concave portion of the support arm portion.

It is a perspective view which shows an example of the tuning fork type bending quartz crystal vibrator concerning a first embodiment of the present invention. It is a perspective view which shows an example of the piezoelectric piece used for the tuning fork type bending quartz crystal vibrator concerning a first embodiment of the present invention. It is a perspective view which shows an example of the tuning fork type | mold bending crystal oscillator based on 2nd embodiment of this invention. It is a conceptual diagram which shows an example of the state of a 1st recessed part. It is a perspective view which shows an example of the piezoelectric piece used for the tuning fork type bending quartz crystal vibrator concerning a third embodiment of the present invention. It is a perspective view which shows an example of the piezoelectric piece used for the tuning fork type bending quartz crystal vibrator concerning the modification of the third embodiment of the present invention. It is a perspective view which shows an example of the piezoelectric piece used for the tuning fork type bending quartz crystal vibrator concerning a 4th embodiment of the present invention. It is a perspective view which shows an example of the piezoelectric piece used for the tuning fork type bending quartz crystal vibrator concerning the modification of the 4th embodiment of the present invention. It is a perspective view which shows an example of the piezoelectric piece used for the tuning fork type bending quartz crystal vibrator concerning a 5th embodiment of the present invention. It is a perspective view which shows an example of the piezoelectric piece used for the tuning fork type bending quartz crystal vibrator concerning a 6th embodiment of the present invention. It is a perspective view which shows an example of the conventional tuning fork type bending crystal oscillator. It is a perspective view which shows an example of the piezoelectric piece used for the conventional tuning fork type bending crystal oscillator.

  The best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described in detail with reference to the drawings as appropriate. Note that each component is exaggerated for easy understanding of the state.

(First embodiment)
As shown in FIG. 1, the tuning-fork type bending crystal resonator 100 according to the first embodiment of the present invention includes a piezoelectric piece 110a (see FIG. 2) and an excitation electrode 121a provided on the surface of the piezoelectric piece 110a. 121b, 122a and 122b, connection electrodes 123a and 123b, frequency adjusting metal films 124a and 124b, and conductive wiring patterns 125, 126 and 127.

As shown in FIGS. 1 and 2, the piezoelectric piece 110 a is made of, for example, quartz and has a flat plate-like base portion 111 and two pairs of vibrating arm portions 112 extending in the same direction from one side of the base portion 111. The support arm 113 extends from the base 111.
In addition, since the vibration arm part 112 is a pair of two, it demonstrates as the 1st vibration arm part 112a and the 2nd vibration arm part 112b.

The support arm portion 113 is between the first vibrating arm portion 112a and the second vibrating arm portion 112b of the base 111, and the direction in which the first vibrating arm portion 112a and the second vibrating arm portion 112b extend. Extends from the base 111 in the same direction.
The support arm 113 is provided with a first recess 31.

The first recess 31 of the support arm 113 is formed in a groove shape and is provided over the entire width of the support arm 113. Such an outer shape of the first recess 31 can be formed by using a well-known photolithography technique and etching technique.
The first recess 31 is provided at a position away from a position where a conductive adhesive used for mounting is attached. For example, when the tip portion of the support arm portion 113 is a portion to which a conductive adhesive can be applied, the support arm portion 113 is provided at a position away from the intermediate portion of the support arm portion 113 toward the base 111 side.

  In the support arm portion 113, the direction perpendicular to the direction extending from the first vibrating arm portion 112a and the second vibrating arm portion 112b is defined as the width, and the extending direction is defined as the length direction.

The cross-sectional shape of the first recess 31 may be formed in, for example, a U-shape, a V-shape, or a cross-sectional shape in which wall surfaces are formed so that the inclination angles are different.
Further, the first recess 31 is formed with a depth exceeding the center of the thickness of the support arm 113.
Accordingly, the first concave portion 31 can attenuate the vibration leaking from the vibrating arm portion 112 and attenuate the vibration propagating to the supporting portion.

As shown in FIG. 1, the excitation electrode 121a is provided on the front and back main surfaces of the first vibrating arm portion 112a. In addition, the excitation electrode 121b is provided on both opposing side surfaces of the first vibrating arm portion 112a.
The frequency adjusting metal film 124a is provided on the front and back main surfaces of the first vibrating arm portion 112a and is electrically connected to the excitation electrodes 121b provided on both side surfaces of the first vibrating arm portion 112a. Connected.
The connection electrode 123a is provided on the front and back main surfaces of the first support arm 113 on the front and back surfaces on the first vibrating arm 112a side.

The excitation electrode 122a is provided on the front main surface and the side surface of the second vibrating arm portion 112b. The excitation electrode 122b is provided on both opposing side surfaces of the second vibrating arm portion 112b.
The frequency adjusting metal film 124b is provided on the front main surface and the front end of the side surface of the second vibrating arm portion 112b, and is electrically connected to the excitation electrode 122b provided on both side surfaces of the second vibrating arm portion 112b. Connected.
Further, the connection electrode 123b is provided on the front and back main surfaces on the second vibrating arm portion 112b side, which is the tip portion of the first support arm portion 113.

  Note that the tuning fork type quartz crystal resonator 100 can adjust the vibration frequency value to a desired value by increasing or decreasing the amount of metal constituting the frequency adjusting metal films 124a and 124b.

As shown in FIG. 1, the excitation electrodes 121a and 122b, the frequency adjusting metal film 124b, and the connection electrode 123b are electrically connected by, for example, a conductive wiring pattern 126 provided on the surface of the piezoelectric piece 110a. Yes.
The connection electrode 123b is electrically connected to the conductive wiring pattern 126. The conductive wiring pattern 126 is provided on both the front and back main surfaces of the base 111. The conductive wiring pattern 126 is electrically connected to the excitation electrode 122b and the frequency adjusting metal film 124b. The conductive wiring pattern 126 provided on the back main surface of the base 111 is electrically connected to the excitation electrode 121a.

  Further, the excitation electrodes 121b and 122a, the frequency adjusting metal film 124a, and the connection electrode 123a are electrically connected by, for example, a conductive wiring pattern 127 provided on the surface of the piezoelectric piece 110a. The connection electrode 123 a is electrically connected to the excitation electrode 121 b and the frequency adjusting metal film 124 a using the side surface of the support arm 113 and the side surface of the base 111. Further, the conductive wiring pattern 127 provided on the front main surface is electrically connected to the excitation electrode 122a. The excitation electrodes 122 a provided on the front and back main surfaces of the second vibrating arm portion 112 b are electrically connected using the side surfaces of the base portion 111.

  Each excitation electrode, connection electrode, frequency adjusting metal film, and conductive wiring pattern are composed of a Cr layer as a base metal and an Au layer provided on the base metal.

  When vibrating the tuning fork-type bent quartz crystal resonator 100, an alternating voltage is applied to the connection electrodes 123a and 123b. When an electrical state after application is instantaneously captured, the excitation electrode 121b of the first vibrating arm portion 112b has a + (plus) potential, the excitation electrode 121a has a-(minus) potential, and changes from + to-. An electric field is generated. On the other hand, the excitation electrodes 122a and 122b of the second vibrating arm portion 112b at this time have a polarity opposite to the polarity generated in the exciting electrodes 121a and 121b of the first vibrating arm portion 112a. These applied electric fields cause an expansion / contraction phenomenon in the first vibrating arm portion 112a and the second vibrating arm portion 112b, and a bending vibration having a resonance frequency set in each vibrating arm portion 112 is obtained.

  The tuning fork-type bent quartz crystal resonator 100 can form the excitation electrode, the connection electrode, the conductive wiring pattern, and the frequency adjusting metal film on the surface of the piezoelectric piece 110a by the photolithography technique and the vapor deposition technique. Further, the tuning fork type bent quartz crystal resonator 100 is mounted on, for example, an element connection electrode pad formed on the bottom surface in the concave portion of a container body provided with a concave portion having an opening portion on one main surface. The opening is hermetically sealed with a lid to form a piezoelectric vibrator.

According to the tuning fork-type bending quartz crystal resonator 100 described above, the first vibrating arm portion 112a and the second vibrating arm portion are provided by providing the first concave portion 31 over the entire width of the support arm portion 113 constituting the piezoelectric piece 110a. After the vibration leaking from 112b reaches the first recess 31 of the support arm 113, it is attenuated by the base 111 or the support arm in the middle, and then the vibration further propagated in the first recess 31 is attenuated. it can. As a result, the first recess 31 reduces reflection of vibration leaking from the first vibrating arm portion 112a and the second vibrating arm portion 112b, and the first vibrating arm portion 112a and the second vibrating arm portion 112b. Inhibiting the vibration of the can be prevented.
In addition, the first recess 31 of the support arm 113 can be easily formed without considering the etching residue.

(Second embodiment)
As shown in FIG. 3, the tuning fork type bent quartz crystal resonator according to the second embodiment of the present invention includes a first concave portion in which the piezoelectric piece 110 b used in the tuning fork type bent crystal resonator is provided in the support arm portion 113. 31 differs from the first embodiment in that 31 is provided on the front and back main surfaces of the support arm 113.
Hereinafter, the description which overlaps about the component same as 1st embodiment is abbreviate | omitted, and attaches | subjects the same code | symbol.

First, as shown in FIG. 3, the first concave portion 31 provided in the support arm portion 113 is formed on the front and back main surfaces of the support arm portion 113, and the first concave portion 31 and the back main surface side on the front main surface side. The first concave portion 31 on the surface side is not opposed to the first concave portion 31 and is provided at a predetermined interval.
That is, for example, the first recess 31 provided on the back main surface is provided at a position closer to the base 111 side than the first recess 31 provided on the front main surface.

The first recess 31 will be specifically described. The depth of the first recess 31 is greater than 50% and less than 90% with respect to the thickness of the base 111.
For example, when the depth of the first concave portion 31 is 50% or less, the vibration propagating through the support arm portion 113 passes through the first concave portion 31 and the vibration leaks, and the CI value is set. It becomes difficult to improve. Moreover, when the depth of the 1st recessed part 31 is 90% or more, the intensity | strength of the support arm part 113 cannot be ensured and there exists a possibility of damaging in the middle of manufacture.
Therefore, as shown in FIG. 4, the first concave portion 31 attenuates the vibration W propagating on the front main surface by the first concave portion 31 provided on the front main surface side, and propagates the vibration W propagating on the back main surface. Is attenuated by the first recess 31 provided on the back main surface side. In addition, since each first recess 31 is formed with a depth exceeding the center CL of the thickness of the support arm 113, vibration propagating through the support arm 113 is also attenuated by the first recess 31. Can do. Accordingly, the first recess 31 can attenuate the vibration leaking from the vibrating arm portion 112 and further attenuate the vibration propagating to the supporting portion in the support arm portion 113.
Thus, since the 1st recessed part 31 of the front and back main surface of the support arm part 113 is provided with the predetermined space | interval, vibration can be attenuate | damped further.

(Third embodiment)
For example, as shown in FIG. 5, the tuning fork-type bent quartz crystal resonator according to the third embodiment of the present invention is configured so that the supporting arm portion 113 of the piezoelectric piece 110 a used in the first embodiment is replaced by the vibrating arm portion 112. The first vibrating arm portion 112a and the second vibrating arm portion 112b are configured to extend from the base portion 111 in opposite directions.
As an example, the piezoelectric piece 110c shown in FIG. 5 will be described.
The piezoelectric piece 110c includes a base 111, a first vibrating arm 112a and a second vibrating arm 112b extending from the base 111, and the first vibrating arm 112a and the second vibrating arm 112b. Comprises a first support arm 113 extending from the base in the opposite direction.
Further, the support arm portion 113 is provided with a first recess 31 over the entire width.

The first recess 31 of the support arm 113 is formed in a groove shape as described above, and is provided over the entire width of the support arm 113. Such an outer shape of the first recess 31 can be formed by using a well-known photolithography technique and etching technique.
The first recess 31 is provided at a position away from a position where a conductive adhesive used for mounting is attached. For example, when the tip portion of the support arm portion 113 is a portion to which the conductive adhesive is applied, the support arm portion 113 is provided at a position away from the intermediate portion of the support arm portion 113 toward the base 111 side.
Thus, even if it comprises 3rd embodiment, there exists an effect similar to 1st embodiment.

(Modification of the third embodiment)
As shown in FIG. 6, the tuning fork-type bent quartz crystal resonator according to the modification of the third embodiment includes a piezoelectric piece 110 d having a first recess 31 provided in the support arm portion 113 on the front and back main surfaces. This is different from the third embodiment.
In other words, the tuning fork-type bent quartz crystal resonator according to the modification of the third embodiment is different from the second embodiment in that the support arm portion 113 extends from the base portion 111 in the direction opposite to the vibrating arm portion 112. And different.
The first recess 31 of the support arm 113 is provided at a predetermined interval so as not to face the front and back main surfaces of the support arm 113.
The first recess 31 provided on the front main surface side is provided closer to the base 111 than the first recess 31 provided on the back main surface side.
Thus, even if it comprises the modification of 3rd embodiment, there exists an effect similar to 2nd embodiment.

(Fourth embodiment)
The tuning fork-type bent quartz crystal resonator according to the fourth embodiment of the present invention is different from the third embodiment in that the base 111 has the second recess 32.
As shown in FIG. 7, a piezoelectric piece 110e used in a tuning fork-type bent quartz crystal resonator according to the fourth embodiment of the present invention includes a base 111 and a first vibrating arm 112a extending from the base 111. A second vibrating arm portion 112b and a first supporting arm portion 113 extending from the base in a direction opposite to the first vibrating arm portion 112a and the second vibrating arm portion 112b are provided.
Here, the base 111 is provided with the second recess 32 over the entire width, leaving a portion where the conductive wiring pattern is provided in the width direction.
Further, the support arm portion 113 is provided with a first recess 31 over the entire width.
As described above, since the fourth embodiment is configured, in addition to the vibration attenuation by the first recess 31 included in the support arm 113, the vibration attenuation by the second recess 32 included in the base 111 can be performed. Reduction of propagation of vibration leaking from the first vibrating arm portion 112a and the second vibrating arm portion 112b can be improved.

(Modification of the fourth embodiment)
As shown in FIG. 8, in the tuning fork-type bent quartz crystal resonator according to the modification of the fourth embodiment, the piezoelectric piece 110 f has second concave portions 32 extending in the width direction on the front and back main surfaces of the base 111. This is different from the fourth embodiment.
The first recess 31 of the support arm 113 is provided at a predetermined interval so as not to face the front and back main surfaces.
The second recess 32 provided on the back main surface side of the base 111 is closer to the first excitation arm portion 112a and the second excitation arm portion 112b than the first recess 32 provided on the front main surface side. Provided.
Even when the modification of the fourth embodiment is configured in this way, in addition to the vibration attenuation by the first concave portion 31 of the front and back main surfaces of the support arm 113, the second of the front and back main surfaces of the base 111 is provided. Since the vibration can be attenuated by the concave portion 32, it is possible to improve the reduction of the propagation of vibration leaking from the first vibrating arm portion 112a and the second vibrating arm portion 112b.

(Fifth embodiment)
The tuning-fork type bending crystal resonator according to the fifth embodiment of the present invention is a first vibrating arm portion 112 of the piezoelectric pieces 110a to 110f used in the first to fourth embodiments and modifications. The vibrating arm portion 112 a and the second vibrating arm portion 112 b are configured to have a third recess 33.
As an example, a piezoelectric piece 110g shown in FIG. 9 will be described.
The piezoelectric piece 110g includes a base portion 111, a first vibrating arm portion 112a and a second vibrating arm portion 112b extending from the base portion 111, the first vibrating arm portion 112a, and the second vibrating arm portion 112b. And a support arm portion 113 extending from the base portion in the same direction.

A groove-shaped third concave portion 33 is provided in the first vibrating arm portion 112a and the second vibrating arm portion 112b.
These third recesses 33 are the same as the extending direction extending from the bases of the first vibrating arm portion 112a and the second vibrating arm portion 112b, and the first vibrating arm has a predetermined depth. It is formed in the part 112a and the 2nd vibration arm part 112b.
The third recess 33 is provided in the first vibrating arm portion 112a and the second vibrating arm portion 112b so as to be shorter than the first vibrating arm portion 112a and the second vibrating arm portion 112b. It is done.
Such a third recess 33 does not play a role of reducing the propagation of vibration, and plays a role of stabilizing the bending vibration between the first vibrating arm portion 112a and the second vibrating arm portion 112b.
The first support arm 113 is provided with a first recess 31 over its entire width.
The first recess 31 of the support arm 113 is provided on the front and back main surfaces at a predetermined interval so as not to face each other.
Thus, even if it comprises 5th embodiment, the vibration which leaks from the vibration arm part 112 can be attenuated.

(Sixth embodiment)
The tuning-fork type quartz crystal resonator according to the sixth embodiment of the present invention is a first vibrating arm portion 112 of the piezoelectric pieces 110a to 110f used in the first to fourth embodiments and the modified examples. Each of the vibrating arm portions 112a and the second vibrating arm portions 112b includes two pairs of third concave portions 33.
As an example, the piezoelectric piece 110h shown in FIG. 10 will be described.
The piezoelectric piece 110h includes a base 111, a first vibrating arm 112a and a second vibrating arm 112b extending from the base 111, the first vibrating arm 112a, and the second vibrating arm 112b. And a support arm portion 113 extending from the base portion in the same direction.

For example, two groove-shaped third concave portions 33 are provided in the first vibrating arm portion 112a and the second vibrating arm portion 112b.
These third recesses 33 are the same as the extending direction extending from the bases of the first vibrating arm portion 112a and the second vibrating arm portion 112b, and the first vibrating arm has a predetermined depth. It is formed in the part 112a and the 2nd vibration arm part 112b.
The third recess 33 is provided in the first vibrating arm portion 112a and the second vibrating arm portion 112b so as to be shorter than the first vibrating arm portion 112a and the second vibrating arm portion 112b. It is done.
Such a third recess 33 does not play a role of reducing the propagation of vibration, and plays a role of stabilizing the bending vibration between the first vibrating arm portion 112a and the second vibrating arm portion 112b.

The support arm 113 is provided with a first recess 31 over its entire width.
The first recess 31 of the support arm 113 is provided on the front and back main surfaces at a predetermined interval so as not to face each other.
Thus, even if it comprises 6th embodiment, the vibration which leaks from the vibration arm part 112 can be attenuated.

In addition, although embodiment of this invention was described, this invention can be changed suitably.
For example, it is needless to say that the present invention includes a tuning fork-type bent quartz crystal having a structure obtained by variously combining the second to sixth embodiments based on the first embodiment.
Moreover, you may provide the 1st recessed part 31 and the 2nd recessed part so that two or more may be arranged in one main surface or both main surfaces.
Even if a tuning fork type bending crystal resonator is configured as described above, the vibration leaking from the vibrating arm portion is attenuated, the propagation of the vibration to the supporting portion is reduced, and the deterioration of the temperature characteristic and the CI value is reduced. Can do.

DESCRIPTION OF SYMBOLS 100 Tuning fork type quartz crystal vibrator 31 1st recessed part 32 2nd recessed part 33 3rd recessed part 110a-110h Piezoelectric piece 111 Base 112 Vibration arm part 112a 1st vibration arm part 112b 2nd vibration arm part 113 Support arm Part

Claims (7)

A base, a pair of vibrating arms extending from the base, and a supporting arm extending from the base along the vibrating arm,
The support arm has a groove-shaped first recess across the entire width in the width direction;
A tuning fork-type bent quartz crystal resonator, characterized in that the support arm portion is provided between the vibrating arm portions provided in pairs. The support arm portion is
2. The tuning fork-type bending crystal resonator according to claim 1, wherein the first concave portion is provided on both main surfaces of the support arm portion, and is provided at a predetermined interval without facing each other.   The tuning fork-type bending crystal resonator according to claim 1, wherein the support arm portion is configured to extend in a direction opposite to the vibrating arm portion extending from the base portion. The base is
4. The tuning fork-type bent quartz crystal resonator according to claim 3, further comprising a groove-shaped second concave portion in a direction perpendicular to a direction in which the vibrating arm portion extends. The base is
5. The tuning-fork type bent quartz crystal resonator according to claim 4, wherein the second concave portion is provided on both main surfaces of the base portion, and is provided at a predetermined interval without facing each other.   6. Each of the two pairs of vibrating arm portions is configured to have a groove-shaped third recess that is shorter than the vibrating arm portion. The tuning-fork type bending crystal resonator according to item.   2. Each of the pair of vibrating arm portions is configured to have a groove-shaped third recess that is arranged at least two shorter than the vibrating arm portion. 6. A tuning-fork type bending crystal resonator according to any one of 5 above.

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