JP6286842B2 - Bending vibration piece, vibration device, electronic device, and moving body - Google Patents

Description

  The present invention relates to a bending vibration piece having a pair of vibrating arms, a vibration device including the bending vibration piece, an electronic apparatus, and a moving body.

Bending vibration pieces using piezoelectric materials are widely used in communication devices such as portable terminals, information devices such as personal computers, and various other electronic devices.
In general, a tuning fork type bending vibration piece that vibrates in a bending vibration mode has a structure in which grooves are formed in the longitudinal direction of the front and back surfaces of a vibrating arm and an excitation electrode is formed on the inner main surface side in order to suppress the CI value. Widely adopted.

  Further, a tuning fork-type bending vibration piece having a structure in which a support arm extending in parallel with the vibrating arm from the base is provided in a frame shape and fixedly supported by the support arm is known. This tuning fork-type flexural vibration piece is reduced in size by shortening the length of the base portion in the longitudinal direction, and the distance from the vibrating arm to the fixing position of the support arm is increased to suppress vibration leakage.

  In addition, with further downsizing of electronic devices and the like, tuning fork-type bending vibration pieces including a pair of vibrating arms extending from the base and a supporting arm extending from the base along the vibrating arm are known. As a bending vibrator using such a tuning fork type bending vibration piece, there is a tuning fork type bending vibrator disclosed in Patent Document 1. A tuning fork-type bending vibrator disclosed in Patent Literature 1 includes a base, a pair of vibrating arms extending from the base, and a support arm extending from the base along the vibrating arm between the vibrating arms. A groove-shaped first recess is formed over the entire width of the arm in the width direction.

  According to the tuning fork type bending vibrator having such a configuration, the vibration leaking from the vibrating arm can be attenuated by the first recess of the support arm, the propagation of vibration to the support arm can be reduced, the temperature characteristics and Deterioration of the CI value can be prevented.

JP 2011-15101 A

The flexural vibration piece that vibrates in the flexural vibration mode causes vibration leakage from the vibration arm to the support arm through the base, resulting in an increase in CI value and poor vibration characteristics.
Therefore, it is conceivable to reduce the vibration leakage by increasing the shape of the support arm or the base and increasing the distance between the vibration arm and the support arm, but this is contrary to the demand for downsizing the flexural vibration piece.

  In order to reduce vibration leakage with a small mass element while reducing the shape of the support arm or the base, the present applicant has made various studies on the flexural vibration piece provided with a protrusion on the base. As a result, it was found that vibration leakage can be reduced as compared with a conventional vibrating piece having no protrusion at the base.

  In view of the above problems, an object of the present invention is to provide a bending vibration piece, a vibration device, an electronic apparatus, and a moving body that can reduce vibration leakage of a vibrating arm.

  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.

Application Example 1 A base, a first vibrating arm extending from one end of the base, a second vibrating arm aligned with the first vibrating arm in plan view, and the first vibrating arm And a support arm extending from the one end side of the base, and in a direction orthogonal to the extending direction of the first vibrating arm. Bending vibration characterized in that a protrusion is provided on at least one of the range of the width of the vibrating arm and the range of the width of the support arm on the other end side of the base portion with the direction along the width as the width direction. Fragment.
The flexural vibrating piece that supports a pair of vibrating arms with a supporting arm between them is because the supporting arms are fixed to the package via the electrode pad and conductive adhesive when the pair of vibrating arms are bent and deformed in opposite phases to each other. The base portion bends and deforms in the extending direction of the vibrating arm, and in particular, the base portion located between the base end of the supporting arm and the proximal end of the vibrating arm, and the extending direction of the vibrating arm. The base portion located in the opposite direction is greatly bent. If a weight such as a protrusion is formed in this area, the vibration changes easily because the moment changes due to the protrusion and the left and right vibrating arms are flexibly vibrating with a good balance around the support arm. Become. However, when the protrusion at the other end of the base portion according to the above configuration is formed in a region that overlaps at least one of the width of the support piece and the width of the support arm at one end of the base portion with the base portion interposed therebetween, the support arm is the center. In a state where the left and right vibrating arms are flexibly oscillating in a well-balanced manner, a balanced state can be maintained without changing the moment due to the protrusion, and the occurrence of vibration leakage can be reduced.

Application Example 2 The support arm includes a tapered portion at a base portion with the base portion, and the protrusion excludes a range of a boundary width along the width direction between the tapered portion and the base portion. The bending vibration piece according to Application Example 1, wherein the bending vibration piece is provided on the other end side in a range of a width defined by both side surfaces of the support arm.
According to the above configuration, in a state where the left and right vibrating arms are flexibly oscillating in a well-balanced manner with the support arm as the center, a balanced state is maintained without changing the moment due to the protrusion, and in particular, the occurrence of vibration leakage is reduced. Can do.

[Application Example 3] The bending according to Application Example 1 or 2, wherein the width of the other end of the base portion gradually decreases in the direction opposite to the extending direction of the support arm. Vibrating piece.
According to the said structure, the rigidity of the connection position periphery of a support arm and a base can be improved, and a vibration leak can be reduced. Further, the vibration at the base caused by the bending vibration of the vibrating arm is canceled (relaxed / absorbed) by the reduced width portion, so that the vibration of the support arm connected to the base is reduced. Therefore, vibration leakage can be suppressed as compared with a flexural vibration piece having a base portion without a reduced width portion when the fixing portion to be mounted on the package is provided on the support arm.

Application Example 4 The vibrating arm includes a tapered portion on a side close to an end portion in the width direction of the base portion, and the protrusion extends in the width direction between the tapered portion and the base portion of the vibrating arm. The bending vibration piece according to Application Example 3, wherein the bending vibration piece is provided on the other end side in a range of a boundary width along the boundary.
According to the said structure, since it is a location which is hard to receive the influence of the bending deformation of a base, generation | occurrence | production of a vibration leak can be reduced.

Application Example 5 A vibration device comprising the bending vibration piece according to any one of Application Examples 1 to 4.
According to the above configuration, it is possible to provide a vibration device that reduces vibration leakage and reduces the CI value and has excellent vibration characteristics.

[Application Example 6] An electronic apparatus comprising the flexural vibration piece according to any one of Application Examples 1 to 4.
According to the above configuration, various electronic devices with reduced vibration leakage and reduced CI value and excellent vibration characteristics are provided.

Application Example 7 A moving body comprising the flexural vibration piece according to any one of Application Examples 1 to 4.
According to the above configuration, according to the above configuration, various moving bodies having excellent vibration characteristics can be provided by reducing vibration leakage and reducing the CI value.

It is a top view of the bending vibration piece of this invention. It is the elements on larger scale of the bending vibration piece of this invention. It is a top view of the bending vibration piece of a modification. It is a graph which shows the relationship between the vibration leakage index | exponent of the bending vibration piece of this invention, and the formation location of protrusion of a base other end.

  Embodiments of a flexural vibration piece (also referred to as a vibration piece), a vibration device, an electronic apparatus, and a moving body according to the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a plan view of a flexural vibration piece of the present invention. FIG. 2 is a partially enlarged view of the flexural vibration piece of the present invention. As shown in FIG. 1, the flexural vibration piece 10 of the present invention includes a base 20, a pair of vibrating arms 30 extending from one end 22 of the base 20, and a pair of vibrating arms 30. A support arm 40 extending from one end 22 of the base 20 is provided.

  In the base portion 20 shown in FIG. 1, the side surface on the back side with respect to the one end 22 is the other end 24, and a protruding projection 50 exists on the other end 24 side. The other end 24 extends in a direction perpendicular to the direction in which the vibrating arm 30 extends. In the present embodiment, the one end 22 is, for example, a linear region existing between the vibrating arm 30 and the support arm 40, and the one end 22 and the other end 24 are parallel to each other with the base body interposed therebetween. Is formed. Such a base 20 is formed to have the same length in the length direction parallel to the extending direction of the vibrating arm 30 and the support arm 40.

  In the pair of two vibrating arms 30 (first and second vibrating arms), the arm portion 32 extends in parallel from the proximal end toward the distal end, and is connected to one end 22 of the base portion 20 at each proximal end. Each has a proximal end. Groove portions 34 having, for example, a substantially rectangular shape in plan view are formed on the front and back main surfaces of the vibrating arm 30 as grooves extending in the longitudinal direction.

  The vibration arm 30 has a weight portion at the tip of the arm portion 32, and is a hammer head portion that is a widened portion having a width larger than the width of the arm portion 32 along a direction orthogonal to the extending direction of the vibration arm 30 in plan view. 36 is formed. The hammer head portion 36 has a width wider than the width of the arm portion 32 and is formed in a substantially rectangular shape in plan view, but is not limited to this shape, and faces the tip of the hammer head portion 36. The width may be gradually or stepwise widened. For the purpose of reducing the size of the resonator element, the vibrating arm 30 having such a hammer head portion 36 is less than the conventional type even if the length extending from the base portion 20 is shorter than the conventional type. By setting the mass on the distal end side of the vibrating arm 30 to be large, it is possible to suppress bending vibration at an unnecessarily high frequency. For example, it is possible to maintain the same vibration regardless of the length of the vibrating arm 30. That is, when the hammer arm 36 is provided on the vibrating arm 30, the desired bending vibration frequency can be easily obtained by adjusting the number of times the vibrating arm 30 is bent and deformed by changing the mass of the hammer head 36. Can do. In addition, in the length of the proximal half of the vibrating arm 30 that is flexibly vibrated, the width of the vibrating arm 30 is predominantly the effect of rigidity against bending deformation, whereas the length of the half of the distal end side of the vibrating arm 30 is large. In this case, since the mass load effect is dominant in the width of the vibrating arm 30, the hammer head portion is formed in the area on the tip half side of the vibrating arm 30. It is desirable to form including a high tip region. Further, the length of the hammer head portion 36 formed at the tip of the vibrating arm 30 with respect to the entire length of the vibrating arm 30 is set to 30% to 50%. Further, the width of the arm portion 32 is increased so as to compensate for the decrease in the bending vibration frequency due to the hammer head. As a result, the thermoelastic loss is reduced and the Q value is remarkably increased. Further, the length of the hammer head portion 36 is 1.2% or more and smaller than 30%, so that the excitation formed on the arm portion 32 is increased. Since the area of the electrode (described later) can be increased, the CI value is drastically reduced.

  Exciting electrodes (not shown) are formed on the surfaces of the arm portion 32 and the groove portion 34, and the vibrating arm 30 is formed at a predetermined frequency by applying a predetermined driving voltage to the excitation electrode via an electrode pad 44 described later. It bends and vibrates in directions toward or away from each other.

  The support arm 40 is between the pair of vibrating arms 30, and an arm portion 42 extends from the base portion 20 at one end 22 along the extending direction of the vibrating arm 30. The length of the support arm 40 in the extending direction is shorter than the length of the vibrating arm 30 in the extending direction, and the distal end of the support arm 40 is disposed closer to the base 20 than the connection portion between the arm portion 32 and the hammer head portion 36. It is set to be. That is, it is desirable that the support arm 40 does not exist between the two hammer head portions 36, but it is sufficient that the support arm 40 does not reach the narrowest portion between the two hammer head portions 36. A pair of electrode pads 44 are formed on the bottom surface of the support arm 40. The bending vibration piece 10 can be adhered to a mounting surface such as a package using a conductive adhesive, and the pair of vibration arms 30 can be fixedly supported by the central support arm 40. In addition, the minimum distance between the support arm 40 and the vibrating arm 30 is preferably longer than the minimum distance between the electrode pad 44 and the hammer head portion 36. By doing so, even if the conductive adhesive formed on the electrode pad 44 is formed larger, the possibility of adhering to the vibrating arm 30 is lower than that of the hammer head portion 36, that is, the loss is larger than that of quartz. Since the possibility that the conductive adhesive adheres to the bending deformation portion of the vibrating arm 30 having a great influence on the vibration characteristics is reduced, no fatal characteristic deterioration is caused.

  The connecting positions of the vibrating arm 30 and the supporting arm 40 and the one end 22 of the base 20 are respectively reduced in plan view, and the width of the vibrating arm 30 and the width of the supporting arm 40 decrease from the boundary with the base 20 toward the extending direction. Tapered portions 38 and 46 are formed. The arm portion 32 of the vibrating arm 30 and the arm portion 42 of the support arm 40 extend in a substantially straight line so as to be parallel to each other from the proximal end to the distal end. A region where the width of the support arm 40 becomes narrow may be provided. By doing this, the vibration frequency of the mode in which the two vibrating arms 30 both bend and vibrate in the same direction (hereinafter referred to as the in-phase mode) is changed to the mode in which the two vibrating arms 30 alternately repeat the approach and the separation from each other (hereinafter referred to as the following) Main mode) can be separated from the vibration frequency, and the coupling strength between the in-phase mode and the main mode can be reduced, thereby preventing the main mode vibration leakage from increasing. In particular, when the vibration frequency of the common mode is f1 and the vibration frequency of the main mode is f0, | f1-f0 | / f0 ≧ 10%, more preferably | f1-f0 | / f0 ≧ 20%, The coupling | bonding of both can be suppressed significantly. The arm portion 32 of the vibrating arm 30 and the arm portion 42 of the support arm 40 are not bent at a right angle or an acute angle from the distal end to the proximal end at the connection position with the one end 22 of the base portion 20, but the width thereof. Rounded taper portions 38 and 46 may be provided so that the diameter gradually increases. The tapered portions 38 and 46 are formed between both side surfaces of the vibrating arm 30 and the support arm 40 and one end 22 of the base portion 20. By providing the tapered portions 38 and 46, the strength of the connection position is increased, impact resistance can be improved, and concentration of strain when bending vibration occurs can be avoided. That is, concentration of temperature change (temperature increase or temperature decrease) associated with the occurrence of strain can be avoided and increase in heat flow can be suppressed, so that increase in thermoelastic loss can be suppressed. Note that the width of the vibrating arm 30 of the present embodiment is a region including the width of the arm portion 32 of the vibrating arm 30 and the width of the tapered portions 38 formed on both side surfaces of the arm portion 32. In addition, the width of the support arm 40 in the present embodiment is a region including the width of the arm portion 42 of the support arm 40 and the width of the tapered portions 46 formed on both side surfaces of the arm portion 42.

The other end 24 of the base 20 is formed with one protrusion 50 that protrudes in a direction opposite to the direction in which the vibrating arm 30 and the support arm 40 extend. The protrusion 50 has a protrusion length from the other end 24 of the base 20 as an example of about 30 μm, and the resonance frequency is set higher than the resonance frequency of the pair of vibration arms 30 so as not to resonate with the vibration arms 30. Yes. Further, the width of the protrusion 50 is set smaller than the width of the vibrating arm 30 and the support arm 40.
Then, as shown in FIG. 2, the length from the center line in the extending direction of the support arm 40 to the end of the base portion 20 is L, and the protrusions 50 (projections 50) are formed at the other end of the base 20 from the center line of the support arm 40. (The center line in the projecting direction) of X, the projection 50 is sandwiched between the width of the support arm 40 and the base 20, and the other end of the base 20 is overlapped with a. A range on the side of the projection 50 with the center line as a base point, a range excluding the tapered portion 46, and a range including the tapered portion 38 from the end of the base portion 20 on the side where the projection 50 exists with the support arm 40 as a boundary. The region of the other end 24 is defined as c.

  FIG. 3 is a plan view of a bending vibration piece according to a modification. As shown in the figure, the bending vibration piece 10A of the modification is different from the bending vibration piece 10 shown in FIG. Other configurations are the same as those of the bending vibration piece 10 shown in FIGS. 1 and 2, and the same reference numerals are given and detailed description thereof is omitted. The bending vibration piece 10A of the modified example protrudes from the other end 24A of the base portion 20A in the direction opposite to the extending direction of the support arm 40, and the length in the direction in which the vibrating arms 30 are arranged gradually decreases in the protruding direction. A reduced width portion 26 is provided. According to the flexural vibration piece 10A of the modified example having such a configuration, the vibration at the base caused by the flexural vibration of the vibrating arm is canceled (relaxed / absorbed) by the reduced width portion 26. Therefore, the support arm connected to the base The vibration of becomes small. Therefore, vibration leakage can be suppressed as compared with a flexural vibration piece having a base portion without a reduced width portion when the fixing portion to be mounted on the package is provided on the support arm.

  In addition, the bending vibration pieces 10 and 10A of the present embodiment are made of a known photo-etching technique using a piezoelectric material such as quartz, lithium tantalate, lithium niobate, lithium tetraboat, potassium niobate, potassium phosphate, or langasite. And can be formed into a desired outer shape. As an example, in the case of forming with a crystal having an X axis (electrical axis), a Y axis (mechanical axis), and a Z axis (optical axis) as crystal axes, 0 ° or more and 15 ° or less with respect to the Y axis centering on the X axis. If the coordinate axis forming the angle is the Y ′ axis, the thickness direction in the direction orthogonal to the Y ′ axis and the X axis is generally oriented, and the Y ′ axis direction is orientated in the longitudinal direction of the vibrating arm (hereinafter referred to as this). Called a crystal Z plate).

  The bending vibration pieces 10 and 10A having such a configuration are manufactured by the following process when using quartz as an example. The bending vibration pieces 10 and 10A are manufactured based on a wafer-like base material by polishing the surface of a crystal Z plate to form a flat plate shape. A protective film in which a Cr film or a Ni film is formed on the surface of the quartz wafer and an Au film is laminated on the surface is formed by vapor deposition or sputtering. Then, after applying a resist film on the surface of the protective film, the resist film is patterned by photolithography into a shape slightly wider than the outer shape of the bending vibration pieces 10 and 10A. Next, the protective film is etched away using the patterned resist film as a mask. After peeling off the resist film, the resist film is applied again, and the outer shape and the groove shape including the protrusions 50 are patterned. In this state, the exposed portion of the quartz wafer is etched with hydrofluoric acid to form the outer shape of the bending vibration pieces 10 and 10A.

  Next, the protective film formed in the groove 34 is etched. The crystal surface thus etched and exposed corresponds to the planar shape of the groove 34 formed in the vibrating arm 30. Then, the exposed portion of the quartz wafer is half-etched with hydrofluoric acid for a predetermined time to form a groove 34 in the vibrating arm 30. After the etching of the groove 34, the resist film and the protective film are peeled off.

  The electrode is formed on the entire surface of the quartz wafer with a Cr film or Ni film as a base, and then an electrode film in which an Au film is disposed thereon is formed. Thereafter, the electrode film corresponds to the excitation electrode pattern. After forming the resist film and etching the electrode film to form the excitation electrode, the resist film is peeled off and formed.

  Next, a weight is attached to the tip of the vibrating arm 30. In this method, a metal film such as Au is formed as a weight adjusting film for frequency adjustment on a part or the entire surface of the hammer head portion 36 by vapor deposition or sputtering.

In the rough adjustment of the frequency, a part of the weighting film is irradiated with a laser beam or the like to partially evaporate, and the mass of the hammer head portion 36 is adjusted. Thereby, the bending vibration frequency of the plurality of bending vibration pieces 10 formed on the quartz wafer 60 can be roughly adjusted so as to approach a desired frequency (for example, 32.768 kHz).
Finally, the bending vibration pieces 10 and 10A are separated. That is, the thin connecting portion in the quartz wafer is broken, and the bending vibration piece in the connected state is made into individual pieces.

FIG. 4 is a graph showing the relationship between the vibration leakage index of the flexural vibration piece of the present invention and the location of the protrusion at the other end of the base. Here, as an example, the shape of the bending vibration piece 10 used for the calculation is 860 μm in total length, 248 μm in length L from the center line in the extending direction of the support arm 40 to the end of the base 20, and the center of the support arm 40. The length from the line to the side of the support arm 40 is 50 μm, and the length from the center line of the support arm 40 to the side of the vibrating arm 30 on the support arm 40 side (the side on the inside of the vibrating piece) is 155 μm. The length from the center line of the arm 40 to the side of the vibrating arm 30 on the end side of the base 20 (side of the outside of the vibrating arm 30) is 207 μm, and the projection 50 at the other end of the base 20 from the center line of the support arm 40 The length to the formation location (center line in the protruding direction of the protrusion 50) is X, the protrusion 50 is square in plan view, the length in the protruding direction is 30 μm, the depth of the groove 34 is 45 μm, the hammer head portion The width of 36 is 198 μm and the length of the hammer head 46 is 237 μm. , It is set to 32.768kHz near the bending vibration frequency as. The vibration leakage is calculated as follows assuming that the bending vibration piece 10 is mounted on the package with a 20 μm-thick silicon conductive adhesive and mounted on the ceramic package. .
The elastic energy resulting from the flexural vibration of the flexural vibration piece 10 reaches the conductive adhesive via the support arm 40 and is virtually provided on the back surface (opposite side of the flexural vibration piece 10). The calculation is made on the condition that the bending vibration piece 10 is not returned while being transmitted to the semi-infinite medium having the material constant of the package.
Since this energy transmitted to the semi-infinite medium does not contribute to bending vibration again in the bending vibration piece 10, it becomes a loss due to vibration leakage. The Q value considering only the loss due to the vibration leakage is defined as QLeak (when the vibration leakage increases, QLeak decreases). Further, as can be easily imagined from the mechanism described later, the present invention does not depend on the absolute value of the dimensions, the bending vibration frequency, or the material described above.

  The vertical axis of the graph is the vibration leakage index (Q0 / QLeak). Here, Q0 is a Q value considering only vibration leakage when the projection 50 is not formed on the other end 24 of the base 20, and QLeak is a case where one projection 50 is formed on the other end 24 of the base 20. The Q value considering only vibration leakage is shown. The horizontal axis of the graph is the position (X / L) where the protrusion 50 is formed at the other end 24 of the base 20, and when X / L = 0, the center line of the support arm 40 and the center of the protrusion 50 overlap each other. When L = 1, the end of the base 20 and the center of the protrusion 50 overlap each other. A straight line A passing through the vibration leakage index 1.0 of the graph and parallel to the vertical axis indicates a case where there is no protrusion at the other end of the base of the bending vibration piece. The ◇ plot is the bending vibration piece 10 shown in FIG. 1 in which the one end 22 and the other end 24 of the base 20 are formed in parallel with the base body interposed therebetween. A plot is the bending vibration piece 10A shown in FIG. 3 having the reduced width portion 26 at the other end 24A of the base portion 20A.

  When the vibration leakage index is smaller than 1.0, the vibration leakage is smaller than that of the bending vibration piece in which no protrusion is formed on the other end of the base. In the case of the bending vibration piece 10 shown in FIG. 1, the range of X / L in which the vibration leakage index is smaller than 1.0 is 0 ≦ X / L ≦ 0.17. That is, the protrusion 50 is formed in the region of the other end of the base 20 (arrow a in FIGS. 1 and 2) that overlaps the width of the support arm 40 and the base 20 therebetween.

  The vibrating arm 30 is configured such that the vibrating arm 30 bends and vibrates in an opposite phase at a predetermined frequency by applying a predetermined driving voltage to the excitation electrode. When the pair of vibrating arms 30 is bent and deformed in opposite phases, the support arm 40 is fixed to the package via the electrode pad 44 and the conductive adhesive, so that the base portion 20 is bent and deformed in the extending direction of the vibrating arms 30. In particular, the portion of the base 20 positioned between the base end of the support arm 40 and the base end of the vibrating arm 30 and the base 20 positioned in the direction opposite to the direction in which the vibrating arm extends are connected to the portion. The part will be bent greatly. When a weight such as the protrusion 50 is formed in this region, the moment is changed by the protrusion 50 and becomes unbalanced in a state where the left and right vibrating arms 30 are flexibly oscillating with the support arm 40 as the center. Is likely to occur.

  On the other hand, when the protrusion 50 of the other end 24 of the base 20 is formed in a region overlapping with the width of the support arm 40 of the one end 22 of the base 20 across the base 20, the left and right vibrating arms 30 centering on the support arm 40. In a state where the bending vibration is in a balanced manner, it is possible to maintain a balanced state without the moment being changed by the protrusion, and to reduce the occurrence of vibration leakage.

  Next, in the case of the bending vibration piece 10A shown in FIG. 3, the range of X / L in which the vibration leakage index is smaller than 1.0 is 0 ≦ X / L ≦ 0.12 and 0.8 ≦ X / L ≦ 1. .0. That is, the protrusion 50 of the other end 24A of the base portion 20A is in a width range defined by both side surfaces of the support arm 40 excluding the boundary width range along the width direction between the taper portion 46 and the base portion 20. The region on the end 24A side (arrow b in FIG. 2) and the vibrating arm 30 include a tapered portion 38 on the side close to the end portion in the width direction of the base portion 20, and the tapered portion 38 and the base portion of the vibrating arm 30 are provided. This is a case where it is formed in a region (arrow c in FIG. 2) on the other end 24A side in the range of the width of the boundary along the width direction with 20. 3A and 3B, the protrusion 50 has both sides of the arm portion 42 of the support arm 40 except for the tapered portion 46 provided at the connecting position between the side surface of the arm portion 42 of the support arm 40 and the one end 22A of the base portion 20. The form formed in the area | region (arrow b of the figure) inside a surface is shown.

  The flexural vibration piece 10A shown in FIG. 3 projects toward the other end 24A of the base portion 20A in the direction opposite to the extending direction of the support arm 40, and the length in the direction in which the vibrating arms 30 are arranged gradually decreases in the projecting direction. A reduced width portion 26 is provided. In the flexural vibration piece 10A, the rigidity of the connecting portion between the support arm 40 and the base 20 is increased, and the vibration at the base due to the flexural vibration of the vibration arm is canceled (relaxed / absorbed) by the reduced width portion 26. The bending vibration piece 10A shown in FIG. 3 can significantly reduce vibration leakage compared to the bending vibration piece 10 of FIG. However, when the pair of vibrating arms 30 is bent and deformed in opposite phases, the base portion 20A is bent and deformed in the extending direction of the vibrating arms 30. In particular, the base end of the support arm 40A and the base end of the vibrating arm 30 The portion of the base portion 20A located between the two and the portion of the base portion 20A located in the direction opposite to the extending direction of the vibrating arm is bent slightly. For this reason, when a weight such as the protrusion 50 is formed in this region, in the state where the left and right vibrating arms 30 are flexibly vibrating in a balanced manner with the support arm 40 as the center, the moment is changed by the protrusion, resulting in an unbalance and vibration leakage. Is likely to occur.

  On the other hand, both side surfaces of the arm portion 42 of the support arm 40 excluding the tapered portion 46 provided at the connection position between the side surface of the arm portion 42 of the support arm 40 and the one end 22A of the base portion 20 at the other end 24A of the base portion 20A. If the left and right vibrating arms 30 are flexibly oscillating in a well-balanced manner with the support arm 40 as the center, the moment does not change due to the protrusion. Therefore, the balanced state can be maintained and the occurrence of vibration leakage can be reduced. Furthermore, when the protrusion 50 of the other end 24A of the base 20A is formed in a region (arrow c in FIG. 2) that overlaps the width of the vibrating arm 30 of the one end 22A of the base 20A across the base 20A, Since this is a part that is not easily affected by bending deformation, the occurrence of vibration leakage can be reduced.

  According to such a flexural vibration piece of the present invention, the protrusion at the other end of the base is formed in a region overlapping with at least one of the width of the support piece and the width of the support arm at one end of the base with the base interposed therebetween. Therefore, in a state where the left and right vibrating arms are flexibly vibrating in a well-balanced manner with the support arm as the center, it is possible to maintain a balanced state without changing the moment due to the protrusions and reduce the occurrence of vibration leakage.

  The present invention is not limited to the above embodiments, and can be implemented with various modifications or changes within the technical scope thereof. For example, the pair of two vibrating arms can be applied even when the arm portion is extended substantially linearly from the proximal end to the distal end without forming the hammer head portion at the distal end.

  Further, the flexural vibration piece of the present invention can be mounted on packages having various structures, and can be applied to various vibration devices other than vibrators such as an oscillator combined with a circuit element having an oscillation circuit.

  In addition, the bending vibration piece of the present invention is combined with a circuit element having an oscillation circuit, so that a digital mobile phone, a personal computer, a (mobile personal computer), an electronic watch, a video recorder, a video camera, a television, a digital still camera, Inkjet dispenser (for example, inkjet printer), laptop personal computer, car navigation device, pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic game device, word processor, workstation, videophone, crime prevention TV monitors, electronic binoculars, POS terminals, medical devices (eg, electronic thermometers, blood pressure monitors, blood glucose meters, electrocardiogram measuring devices, ultrasonic diagnostic devices, electronic endoscopes), fish detectors, various measuring devices, instruments (eg, ,vehicle Aircraft instruments and a ship), it can be used widely as an electronic device such as a flight simulator.

  Moreover, the bending vibration piece of the present invention is mounted on an automobile. Bending vibration pieces include keyless entry, immobilizer, car navigation system, car air conditioner, anti-lock brake system (ABS), air bag, tire pressure monitoring system (TPMS), engine control, hybrid car and It can be widely applied to electronic control units (ECUs) such as battery monitors for electric vehicles, vehicle body posture control systems, and the like.

10, 10A ......... Bending vibration piece, 20, 20A ......... Base, 22, 22A ......... One end, 24, 24A ......... Other end, 26 ......... Reduced width portion, 30 ......... Vibrating arm, 32... Arm portion 34... Groove portion 36... Hammer head portion 40... Support arm 42 42 Arm portion 44 Electrode pad 50 Projection

Claims (8)

One end and a base opposite to the one end and having the other end that is linear in plan view ;
A first vibrating arm and the second vibrating arm extends in one direction from the one end side of the base,
And it extends in the one direction from the one end side of the base, support arms which are disposed between the first vibrating arm and the second vibrating arms in the width direction orthogonal to the one direction When,
A front Symbol other end side, and a single projection provided on the range of the width of the front Symbol support arms,
A flexural vibration piece comprising: The support arm is provided with support arm taper portions on both side surfaces that intersect the width direction at a base portion with the base portion,
The bending vibration piece according to claim 1, wherein the range of the width of the support arm is a range including a width defined by the both side surfaces of the support arm and a width of the taper portion of the support arm. A base having one end and the other end opposite to the one end;
A first vibrating arm and a second vibrating arm extending along one direction from the one end side of the base;
A support arm that extends along the one direction from the one end side of the base and is disposed between the first vibrating arm and the second vibrating arm in a width direction orthogonal to the one direction. When,
With
The width in the width direction of the other end is gradually reduced toward the opposite direction to the one direction,
The first vibrating arm has a first vibrating arm taper portion on a side surface opposite to the support arm side among both side surfaces intersecting in the width direction,
The second resonating arm has a second resonating arm taper portion on a side surface opposite to the support arm side among both side surfaces intersecting in the width direction,
A single projection on either the other end side of the width range of the first vibrating arm tapered portion, the width range of the second vibrating arm tapered portion, or the width range of the support arm. A bending vibration piece characterized in that is provided. The support arm is provided with support arm taper portions on both side surfaces that intersect the width direction at a base portion with the base portion,
The bending vibration piece according to claim 3 , wherein a range of the width of the support arm is a range of a width defined by the both side surfaces of the support arm. Vibrating device characterized in that it comprises a bending vibration piece according to any one of claims 1 to 4. The bending vibration piece according to any one of claims 1 to 4 ,
A package having a mounting surface to which the bending vibration piece is fixed;
With
An electrode pad is provided on one main surface of the support arm of the bending vibration piece,
The vibration device, wherein the electrode pad is fixed to the mounting surface via an adhesive. An electronic apparatus comprising: a bending vibration piece according to any one of claims 1 to 4. Mobile, characterized in that it comprises a bending vibration piece according to any one of claims 1 to 4.

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