JP2020014257A - Vibration element, vibrator, oscillator, electronic device, and mobile unit - Google Patents

Abstract

To provide a vibration element capable of exerting excellent vibration characteristics with low power consumption, and a vibrator, an oscillator, an electronic device, and a mobile unit having the vibration element.SOLUTION: A vibration element 2 comprises: a stem 4; a pair of vibration arms 5 and 6 extending from the stem 4; and a crystal substrate 3 having a supporting arm 71 extending from the stem 4 to a side same as the vibration arms side between the vibration arms 5 and 6. The vibration arm 5 has an arm part 51, and a hammer head 59 provided on a tip of the arm part 51. The arm part 51 has a pair of main surfaces, and a groove with a bottom surface opened to these main surfaces. Width of bank parts arranged across the groove along a width direction perpendicular to a longer direction of the vibration arm of the main surface, is 6 μm or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vibrating element, a vibrator, an oscillator, an electronic device, and a moving body.

Conventionally, a vibrating element using quartz has been known (for example, see Patent Document 1). Such a vibrating element has been widely used as a reference frequency source and a transmission source of various electronic devices because of its excellent frequency-temperature characteristics.
The vibration element described in Patent Literature 1 has a tuning fork shape, and has a base and a pair of vibrating arms extending from the base. Each vibrating arm is formed with a pair of grooves that are open on the upper and lower surfaces. Therefore, each vibrating arm has a substantially H-shaped cross-sectional shape. By forming the vibrating arm in such a shape, thermoelastic loss can be reduced, and excellent vibration characteristics can be exhibited. However, conventionally, the shape (including the size) of the vibrating arm around the groove has not been sufficiently studied.

JP-A-2-32229

  An object of the present invention is to provide a vibrating element capable of exhibiting excellent vibration characteristics with low power consumption, and a vibrator, an oscillator, an electronic device, and a moving body including the vibrating element.

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 application examples.
[Application Example 1]
A vibration element of the present invention includes a first end and a base including a second end opposite to the first end in plan view;
The base is provided integrally with the base, and extends along the first direction from the base on the first end side of the base, and is arranged along a second direction orthogonal to the first direction. A pair of vibrating arms,
Each said vibrating arm,
Arms and
A wide portion that is located on the opposite side of the base portion side of the arm portion and has a greater length along the second direction than the arm portion;
Each said vibrating arm,
A pair of main surfaces in a front-to-back relationship,
A bottomed groove provided in each of the main surfaces,
In the main surface of each of the arm portions, a width of each of the portions arranged along the second direction with the groove interposed therebetween is 6 μm or less.
As a result, the equivalent series resistance R1 (CI value) can be sufficiently reduced while maintaining the Q value of the resonator element relatively high. As a result, it is possible to obtain a vibration element that can exhibit excellent vibration characteristics with low power consumption.

[Application Example 2]
In the vibration element according to the aspect of the invention, it is preferable that the width be 1 μm or more and 3 μm or less.
Thereby, R1 (CI value) of the vibration element can be made smaller, and the vibration element can be driven with lower power consumption.
[Application Example 3]
In the vibration element of the present invention, the maximum depth of the groove is t [μm],
When the thickness of the vibrating arm is T [μm],
Η represented by 2t / T is preferably 0.6 or more.
Accordingly, the area for forming the driving electrode can be increased, so that R1 (CI value) of the vibration element can be further reduced, and the vibration element can be obtained with lower power consumption.
[Application Example 4]
In the vibrating element of the present invention, it is preferable that the thickness of the vibrating arm is 50 μm or more.
Thereby, R1 of the vibration element can be made smaller.

[Application Example 5]
In the vibration element according to the aspect of the invention, it is preferable that the vibration element include a support portion that supports the base.
Thereby, vibration leakage of the vibration element can be more effectively reduced.
[Application Example 6]
In the vibration element according to the aspect of the invention, it is preferable that the support section include a support arm extending along the first direction from the base between the pair of vibrating arms.
Thereby, vibration leakage of the vibration element can be more effectively reduced.

[Application Example 7]
In the vibration element according to the aspect of the invention, it is preferable that the support portion include a support arm extending from the base on the second end side of the base.
Thereby, vibration leakage of the vibration element can be more effectively reduced. Further, since there is no need to provide a support arm between the vibrating arms, the length (width) of the vibrating element along the second direction can be reduced.

[Application Example 8]
In the vibration element according to the aspect of the invention, it is preferable that the support portion includes a frame body that surrounds at least the base portion, the vibrating arm, and the support arm, and is connected to the support arm.
Thus, the vibration element can be accurately fixed to the base of the package via the frame, for example. Therefore, the size of the vibration element can be increased, and as a result, its R1 can be further reduced.

[Application Example 9]
In the vibration element according to the aspect of the invention, it is preferable that the support portion include a frame body that surrounds at least the base portion and the vibrating arm.
Thus, the vibration element can be accurately fixed to the base of the package via the frame, for example. Therefore, the size of the vibration element can be increased, and as a result, its R1 can be further reduced.

[Application Example 10]
In the vibration element according to the aspect of the invention, the base may have a length along the second direction on at least one of the first end side and the second end side between the pair of vibrating arms. It is preferable to include a reduced width portion that decreases continuously or stepwise as the distance from the center of the base portion increases along the center line of the base portion.
When the base has the reduced width portion, vibration leakage of the vibration element can be effectively suppressed.

[Application Example 11]
The vibrator of the present invention is a vibrating element of the present invention,
And a package on which the vibration element is mounted.
As a result, a highly reliable oscillator can be obtained.

[Application Example 12]
An oscillator according to the present invention includes a vibrating element according to the present invention,
And an oscillation circuit.
Thereby, a highly reliable oscillator can be obtained.

[Application Example 13]
An electronic device according to another aspect of the invention includes the vibration element according to the aspect of the invention.
Thereby, a highly reliable electronic device can be obtained.
[Application Example 14]
A moving object according to the present invention includes the vibration element according to the present invention.
Thereby, a highly reliable moving object can be obtained.

FIG. 2 is a plan view of the vibrator according to the first embodiment of the present invention. It is AA sectional drawing in FIG. It is a top view explaining the principle of vibration leak reduction. It is BB sectional drawing in FIG. It is sectional drawing of the resonating arm explaining the heat conduction at the time of bending vibration. It is a graph which shows the relationship between Q value and f / fm. It is sectional drawing which shows the resonating arm formed by wet etching. It is a graph which shows the relationship between W3 and Q value. It is a graph which shows the relationship between W3 and 1 / R1. It is a top view of a vibration element which a transducer concerning a 2nd embodiment of the present invention has. It is a top view of a vibrator concerning a 3rd embodiment of the present invention. It is CC sectional view taken on the line in FIG. It is a top view of the vibration element which the transducer concerning a 4th embodiment of the present invention has. FIG. 2 is a cross-sectional view showing a preferred embodiment of the oscillator according to the present invention. FIG. 11 is a perspective view illustrating a configuration of a mobile (or notebook) personal computer to which an electronic device including the vibration element according to the invention is applied. FIG. 2 is a perspective view showing a configuration of a mobile phone (including a PHS) to which an electronic device including the vibration element of the invention is applied. FIG. 2 is a perspective view illustrating a configuration of a digital still camera to which an electronic device including the vibration element according to the invention is applied. FIG. 1 is a perspective view schematically showing an automobile as an example of a moving object of the present invention.

Hereinafter, a vibrating element, a vibrator, an oscillator, an electronic device, and a moving body of the present invention will be described in detail based on preferred embodiments shown in the drawings.
First, a vibrator to which the vibrating element of the present invention is applied (vibrator of the present invention) will be described.

<First embodiment>
1 is a plan view of a vibrator according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a plan view for explaining the principle of vibration leakage reduction. 4 is a cross-sectional view taken along the line BB in FIG. 1, FIG. 5 is a cross-sectional view of the vibrating arm for explaining heat conduction during flexural vibration, and FIG. 6 is a graph and a graph showing the relationship between the Q value and f / fm. 7 is a sectional view showing a vibrating arm formed by wet etching, FIG. 8 is a graph showing a relationship between W3 and a Q value, and FIG. 9 is a graph showing a relationship between W3 and 1 / R1. In the following, for convenience of explanation, as shown in FIG. 1, three axes orthogonal to each other are defined as an X axis (electric axis of quartz), a Y axis (mechanical axis of quartz), and a Z axis (optical axis of quartz). .

1. 1. Vibrator The vibrator 1 shown in FIGS. 1 and 2 includes a vibrating element 2 (the vibrating element of the present invention) and a package 9 that houses the vibrating element 2. Hereinafter, the vibration element 2 and the package 9 will be sequentially described in detail.
(Vibration element 2)
As shown in FIGS. 1, 2 and 4, the vibrating element 2 has a quartz substrate 3 and first and second driving electrodes 84 and 85 formed on the quartz substrate 3. 1 and 2, illustration of the first and second driving electrodes 84 and 85 is omitted for convenience of explanation.
The crystal substrate 3 is made of a Z-cut crystal plate. Thereby, the vibration element 2 can exhibit excellent vibration characteristics. The Z-cut quartz plate is a quartz substrate having the Z axis in the thickness direction. The Z axis preferably coincides with the thickness direction of the quartz substrate 3, but may be slightly inclined with respect to the thickness direction from the viewpoint of reducing the frequency temperature change near room temperature.

  That is, when the angle of inclination is θ degrees (−5 degrees ≦ θ ≦ 15 degrees), an orthogonal coordinate system composed of an X axis as an electric axis of the quartz crystal, a Y axis as a mechanical axis, and a Z axis as an optical axis. With the X axis as the rotation axis, the Z axis is inclined by θ degrees so that the + Z side rotates in the −Y direction of the Y axis, the Z ′ axis, and the Y axis rotates in the + Z direction of the Z axis on the + Y side. Assuming that the axis inclined by θ degrees is the Y ′ axis, the thickness along the Z ′ axis is the thickness, and the crystal substrate 3 has a main surface including the X axis and the Y ′ axis.

As shown in FIG. 1, the quartz substrate 3 includes a base 4, a pair of vibrating arms 5, 6 extending from the base 4 on the tip (first end) side of the base 4, and vibrating arms 5, 6. And a supporting arm (supporting portion) 71 extending from the base 4 on the same side as these. Therefore, the base 4, the vibrating arms 5, 6 and the support arm 71 are formed integrally.
The base 4 has a plate shape having a spread in the XY plane and a thickness in the Z-axis direction. The base 4 has a portion (main body 41) for supporting and connecting the vibrating arms 5, 6, and a reduced width portion 42 for reducing vibration leakage.

  The reduced width portion 42 is provided on the base end (second end) side of the main body 41, that is, on the side opposite to the side on which the vibrating arms 5 and 6 extend. The reduced width portion 42 has a width (length along the X-axis direction) from the vibrating arms 5 and 6 along the center line C1 between the vibrating arms 5 and 6, that is, the center of the base 4. It gradually decreases as the distance from the (main body portion 41) increases, and its contour (edge) has an arch shape (arc shape). By having such a reduced width portion 42, vibration leakage of the vibration element 2 can be effectively suppressed.

This will be specifically described as follows. For the sake of simplicity, it is assumed that the shape of the vibration element 2 is symmetric with respect to a predetermined axis (center line C1) parallel to the Y axis.
First, a case where the reduced width portion 42 is not provided as shown in FIG. When the vibrating arms 5 and 6 are bent and deformed so as to be separated from each other, a displacement close to a clockwise rotation occurs as shown by an arrow in the main body portion 41 near where the vibrating arm 5 is connected. In the main body 41 near the arm 6 is connected, a displacement close to a counterclockwise rotation occurs as shown by an arrow (however, strictly speaking, the movement is not a rotation that can be called a rotation movement). , For convenience, "close to rotational movement").

  Since the X-axis direction components of these displacements are opposite to each other, they are offset at the center of the main body 41 in the X-axis direction, and the displacement in the + Y-axis direction remains (however, strictly speaking, the Z-axis direction). Although the displacement in the direction remains, it is omitted here). That is, the main body 41 bends and deforms such that the central portion in the X-axis direction is displaced in the + Y-axis direction. The support arm 71 extends from the main body 41 having the displacement in the + Y-axis direction, and the support arm 71 performs a motion having the displacement in the + Y-axis direction. When the package is fixed to the package via an adhesive, elastic energy accompanying the displacement in the + Y-axis direction leaks to the outside via the adhesive. This is a loss of vibration leakage, which causes a deterioration of the Q value, and consequently a deterioration of the CI value.

  On the other hand, as shown in FIG. 3B, in the case where the reduced width portion 42 is provided, since the reduced width portion 42 has an arched (curved) contour, the rotation described above is performed. Displacements that are close to motion will be stuck together at the reduced width portion 42. That is, the displacement in the X-axis direction is offset at the X-axis central portion of the reduced width portion 42 in the same manner as the X-axis central portion of the main body portion 41, and at the same time, the displacement in the Y-axis direction is suppressed. Become. Further, since the contour of the reduced width portion 42 is arch-shaped, the displacement in the + Y-axis direction that is to be generated in the main body portion 41 is also suppressed. As a result, the displacement in the + Y-axis direction at the center of the base 4 in the X-axis direction when the reduced width portion 42 is provided is much smaller than when the reduced width portion 42 is not provided. That is, a vibration element with small vibration leakage can be obtained.

  Here, the contour of the reduced width portion 42 has an arch shape, but the present invention is not limited to this as long as it exhibits the above-described operation. For example, the width is gradually reduced along the center line C1 in plan view, and the width is reduced along the center line C1 in plan view, and the contour is formed in a stepped (stair-like) shape by a plurality of straight lines. The width is reduced linearly (continuously), and the outline is formed into a mountain shape (triangular shape) by two straight lines, and the width is linear (continuous) along the center line C1 in plan view. And a reduced width portion or the like having an outline formed by three or more straight lines.

  The vibrating arms 5 and 6 are arranged in the X-axis direction (second direction) and extend from the tip of the base 4 along the Y-axis direction (first direction) so as to be parallel to each other. Each of these vibrating arms 5 and 6 has a longitudinal shape, and its base end is a fixed end and its distal end is a free end. The vibrating arms 5 and 6 are respectively provided at the arms 51 and 61 and at the tips (opposite to the base 4) of the arms 51 and 61, and have a substantially rectangular hammer head (arm) when viewed in XY plane. Wide portions 59, 69 having a longer length along the X-axis direction than 51, 61.

  As shown in FIG. 4, the arm portion 51 includes a pair of main surfaces 511 and 512 configured by an XY plane and a pair of side surfaces 513 and 514 configured by a YZ plane and connecting the pair of main surfaces 511 and 512. have. The arm 51 has a groove 52 with a bottom opening to the main surface 511 and a groove 53 with a bottom opening to the main surface 512. Each of the grooves 52 and 53 extends in the Y-axis direction, and the tip is located at the boundary between the arm 51 and the hammer head 59, and the base is located at the base 4. Such an arm portion 51 has a substantially H-shaped cross section at a portion where the grooves 52 and 53 are formed.

  By forming the grooves 52 and 53 in the vibrating arm 5 in this way, it is possible to reduce the thermoelastic loss and exhibit excellent vibration characteristics (described in detail later). The length of the grooves 52, 53 is not limited, and the tip of each groove 52, 53 may be located at the boundary between the arm 51 and the hammer head 59 as in the present embodiment. When the ends of the grooves 52 and 53 are configured to extend to the hammer head 59, stress concentration occurring around the ends of the grooves 52 and 53 is reduced, and there is a risk of breakage or chipping that occurs when an impact is applied. Decrease. Alternatively, when the distal ends of the grooves 52 and 53 are located closer to the base side than in the present embodiment, the stress concentration generated near the boundary between the arm 51 and the hammer head 59 is reduced, so that an impact is applied. The possibility of breakage or chipping occurring at the time is reduced.

  In addition, since the base ends of the grooves 52 and 53 extend to the base 4, stress concentration at these boundaries is reduced. Therefore, the possibility of breakage or chipping occurring when an impact is applied is reduced. Alternatively, if the base ends of the grooves 52 and 53 are configured so as to be located in the Y-axis direction (the direction in which the vibrating arm 5 extends) from the boundary between the base 4 and the arm 51, the vicinity of the boundary between the base 4 and the arm 51 can be obtained. Since the generated stress concentration is reduced, the possibility of breakage or chipping occurring when an impact is applied is reduced.

The positions of the grooves 52 and 53 are adjusted in the X-axis direction with respect to the position of the vibrating arm 5 such that the center of gravity of the cross section of the vibrating arm 5 coincides with the center of the cross-sectional shape of the vibrating arm 5. It is preferably formed. By doing so, unnecessary vibration of the vibrating arm 5 (specifically, oblique vibration having an out-of-plane component) is reduced, so that vibration leakage can be reduced. Further, in this case, since the occurrence of unnecessary vibration is reduced, the driving area is relatively increased and the CI value can be reduced.
The center of the hammer head 59 in the X-axis direction may be slightly shifted from the center of the vibrating arm 5 in the X-axis direction. By doing so, it is possible to reduce the vibration of the base 4 in the Z-axis direction, which is caused by the vibrating arm 5 being twisted at the time of the bending vibration, and thus it is possible to suppress the vibration leakage.

The resonating arm 5 has been described above. The vibrating arm 6 has the same configuration as the vibrating arm 5. That is, the arm portion 61 has a pair of main surfaces 611 and 612 configured on the XY plane and a pair of side surfaces 613 and 614 configured on the YZ plane and connecting the pair of main surfaces 611 and 612. . The arm 61 has a groove 62 with a bottom opening to the main surface 611 and a groove 63 with a bottom opening to the main surface 612. Each of the grooves 62 and 63 extends in the Y-axis direction, the tip is located at the boundary between the arm 61 and the hammer head 69, and the base is located at the base 4. Such an arm portion 61 has a substantially H-shaped cross-sectional shape in a portion where the grooves 62 and 63 are formed.
Further, the center of the hammer head 69 in the X-axis direction may be slightly shifted from the center of the vibrating arm 6 in the X-axis direction. By doing so, it is possible to reduce the vibration of the base 4 in the Z-axis direction caused by the torsion of the vibrating arm 6 at the time of bending vibration, so that it is possible to suppress vibration leakage.

As shown in FIG. 4, a pair of first driving electrodes 84 and a pair of second driving electrodes 85 are formed on the vibrating arm 5. Specifically, one of the first driving electrodes 84 is formed on the inner surface (side surface) of the groove 52, and the other is formed on the inner surface (side surface) of the groove 53. One of the second drive electrodes 85 is formed on the side surface 513, and the other is formed on the side surface 514. Similarly, a pair of first driving electrodes 84 and a pair of second driving electrodes 85 are also formed on the vibrating arm 6. Specifically, one of the first driving electrodes 84 is formed on the side surface 613, and the other is formed on the side surface 614. One of the second drive electrodes 85 is formed on the inner surface (side surface) of the groove 62, and the other is formed on the inner surface (side surface) of the groove 63.
When an alternating voltage is applied between the first and second drive electrodes 84 and 85, the vibrating arms 5 and 6 vibrate at a predetermined frequency in the in-plane direction (XY plane direction) so as to repeat approaching and separating from each other. I do.

  The configuration of the first and second driving electrodes 84 and 85 is not particularly limited, and gold (Au), a gold alloy, platinum (Pt), aluminum (Al), an aluminum alloy, silver (Ag), a silver alloy, Chromium (Cr), chromium alloy, nickel (Ni), nickel alloy, copper (Cu), molybdenum (Mo), niobium (Nb), tungsten (W), iron (Fe), titanium (Ti), cobalt (Co) , Zinc (Zn), zirconium (Zr) and the like, and a conductive material such as indium tin oxide (ITO).

  As a specific configuration of the first and second driving electrodes 84 and 85, for example, a configuration in which an Au layer of 700 ° or less is formed on a Cr layer of 700 ° or less can be used. In particular, since Cr and Au have large thermoelastic loss, the Cr layer and the Au layer are preferably set to 200 ° or less. When the dielectric breakdown resistance is to be increased, the Cr layer and the Au layer are preferably set to 1000 ° or more. Further, since Ni has a coefficient of thermal expansion close to that of quartz crystal, by using a Ni layer as a base instead of a Cr layer, thermal stress caused by the electrodes is reduced, and the vibrating element 2 having good long-term reliability (aging characteristics). Can be obtained.

As described above, in the vibration element 2, the thermoelastic loss is reduced by forming the grooves 52, 53, 62, 63 in the vibration arms 5, 6. Hereinafter, this will be specifically described using the vibrating arm 5 as an example.
As described above, the vibrating arm 5 bends and vibrates in the in-plane direction by applying an alternating voltage between the first and second driving electrodes 84 and 85. As shown in FIG. 5, in this bending vibration, when the side surface 513 of the arm portion 51 contracts, the side surface 514 expands, and when the side surface 513 expands, the side surface 514 contracts. When the vibrating arm 5 does not generate the Gough-Joule effect (energy elasticity is dominant over entropy elasticity), of the side surfaces 513 and 514, the temperature on the shrinking surface side increases, and the temperature on the expanding surface side increases. Because of the lowering, a temperature difference occurs between the side surface 513 and the side surface 514, that is, inside the arm 51. Vibration energy loss occurs due to heat conduction resulting from such a temperature difference, and as a result, the Q value of the vibration element 2 decreases. Energy loss accompanying such a decrease in the Q value is called thermoelastic loss.

When the bending vibration frequency (mechanical bending vibration frequency) f of the vibrating arm 5 changes in the vibrating element that vibrates in the bending vibration mode such as the vibration element 2, the bending vibration frequency of the vibrating arm 5 changes to the thermal relaxation frequency fm. , The Q value becomes minimum. The thermal relaxation frequency fm can be obtained by fm = 1 / (2πτ) (where π is a pi, and if e is a Napier number, τ is a temperature difference due to heat conduction and e ^{− This} is the relaxation time required to multiply by ¹ ).

Further, assuming that the thermal relaxation frequency is fm0 when the vibrating arm 5 is considered to have a flat plate structure (a structure having a rectangular cross section), fm0 can be obtained by the following equation.
fm0 = πk / (2ρCpa ² ) ‥‥ (1)
Here, π is the circular constant, k is the thermal conductivity of the vibrating arm 5 in the vibration direction, ρ is the mass density of the vibrating arm 5, Cp is the heat capacity of the vibrating arm 5, and a is the width of the vibrating arm 5 in the vibration direction (effective Width). When the constant of the material of the vibrating arm 5 (that is, quartz) is input to the thermal conductivity k, the mass density ρ, and the heat capacity Cp of the equation (1), the obtained thermal relaxation frequency fm0 is obtained by forming the grooves 52 and 53 in the vibrating arm 5. This is the value when not provided.

  In the vibrating arm 5, grooves 52 and 53 are formed so as to be located between the side surfaces 513 and 514. Therefore, a heat transfer path for balancing the temperature difference between the side surfaces 513 and 514 generated at the time of bending vibration of the vibrating arm 5 by heat conduction is formed so as to bypass the grooves 52 and 53, and the heat transfer path is formed on the side surfaces 513 and 514. It is longer than the linear distance (shortest distance) between them. Therefore, the relaxation time τ becomes longer and the thermal relaxation frequency fm becomes lower than when the grooves 52 and 53 are not provided in the vibrating arm 5.

  FIG. 6 is a graph showing the f / fm dependency of the Q value of the vibration element in the bending vibration mode. In the figure, a curve F1 indicated by a dotted line indicates a case where a groove is formed in the vibrating arm like the vibrating element 2 (when the cross-sectional shape of the vibrating arm is H-shaped), and is indicated by a solid line. Curve F2 indicates a case where no groove is formed in the vibrating arm (when the cross-sectional shape of the connecting arm is rectangular). As shown in the figure, although the shapes of the curves F1 and F2 do not change, the curve F1 shifts in the frequency decreasing direction with respect to the curve F2 with the decrease in the thermal relaxation frequency fm as described above. Therefore, assuming that the thermal relaxation frequency when the groove is formed in the vibrating arm like the vibrating element 2 is fm1, by satisfying the following expression (2), the vibration in which the groove is formed in the vibrating arm is always satisfied. The Q value of the element becomes higher than the Q value of the vibrating element having no groove formed in the vibrating arm.

Furthermore, a higher Q value can be obtained by limiting the relationship to f / fm0> 1.
In FIG. 6, a region where f / fm <1 is also referred to as an isothermal region. In this isothermal region, the Q value increases as f / fm decreases. This is because the lower the mechanical frequency of the vibrating arm (the slower the vibration of the vibrating arm), the more difficult it is for the temperature difference in the vibrating arm to occur. Therefore, in the limit when f / fm approaches 0 (zero) without limit, an isothermal quasi-static operation is performed, and the thermoelastic loss approaches 0 (zero) without limit. On the other hand, a region where f / fm> 1 is also called an adiabatic region, and in this adiabatic region, the Q value increases as f / fm increases. This is because, as the mechanical frequency of the vibrating arm increases, the switching between the temperature rise and the temperature effect on each side surface becomes faster, and the time required for heat conduction as described above is eliminated. Therefore, in the limit when f / fm is increased without limit, adiabatic operation is performed, and the thermoelastic loss approaches 0 (zero) without limit. Accordingly, satisfying the relationship of f / fm> 1 can be rephrased as f / fm being in the adiabatic region.

  Note that the constituent material (metal material) of the first and second drive electrodes 84 and 85 has a higher thermal conductivity than quartz, which is a constituent material of the vibrating arms 5 and 6, so that the vibrating arm 5 has Heat conduction via the first driving electrode 84 is actively performed, and heat conduction via the second driving electrode 85 is actively performed on the vibrating arm 6. If the heat conduction via the first and second driving electrodes 84 and 85 is actively performed, the relaxation time τ becomes short. Therefore, in the vibrating arm 5, the first driving electrode 84 is divided into the side surfaces 513 and 514 at the bottom surfaces of the grooves 52 and 53. In the vibrating arm 6, the second driving electrode 84 is divided at the bottom surfaces of the grooves 62 and 63. It is preferable to divide the electrode 85 for use into the side surface 613 side and the side surface 614 side to prevent or suppress the above-described heat conduction. As a result, it is possible to prevent the relaxation time τ from becoming short, and to obtain the vibrating element 2 having a higher Q value.

Next, the relationship between the total length of the vibrating arms 5 and 6 and the length and width of the hammer heads 59 and 69 will be described. Since the vibrating arms 5 and 6 have the same configuration, the vibrating arm 5 will be described below as a representative, and the description of the vibrating arm 6 will be omitted.
As shown in FIG. 1, when the total length (length in the Y-axis direction) of the vibrating arm 5 is L [μm] and the length (length in the Y-axis direction) of the hammer head 59 is H [μm], The vibrating arm 5 preferably satisfies the relationship of 0.012 <H / L <0.3, and more preferably satisfies the relationship of 0.046 <H / L <0.223. By satisfying such a relationship, the CI value of the vibrating element 2 can be suppressed to be low, so that the vibrating element 2 has a small vibration loss and excellent vibration characteristics.

  Here, in the present embodiment, the base end of the vibrating arm 5 is defined by a line segment connecting a position where the side surface 514 is connected to the base 4 and a position where the side surface 513 is connected to the base 4. Is set at a position located at the center of the width (length in the X-axis direction). The free end of the arm 51 has a tapered shape whose width gradually increases toward the free end, and the width (length in the X-axis direction) of the tapered portion is equal to the width of the arm 51 (X If the arm 51 has a portion that is 1.5 times or more the axial length), this portion is also included in the length H of the hammer head 59.

  Further, when the width (length in the X-axis direction) of the arm portion 51 is W1 [μm] and the width (length in the X-axis direction) of the hammer head 59 is W2 [μm], It is preferable to satisfy the relationship of 0.5 ≦ W2 / W1 ≦ 10.0, and it is more preferable that the relationship of 1.6 ≦ W2 / W1 ≦ 7.0 is satisfied. By satisfying such a relationship, a wide width of the hammer head 59 can be ensured. Therefore, even if the length H of the hammer head 59 is relatively short as described above (less than 30% of L), the mass effect of the hammer head 59 can be sufficiently exerted. Therefore, by satisfying the relationship 1.5 ≦ W2 / W1 ≦ 10.0, the total length L of the vibrating arm 5 is suppressed, and the size of the vibrating element 2 can be reduced.

As described above, in the vibrating arm 5, by satisfying the relationship of 0.012 <H / L <0.3 and the relationship of 1.5 ≦ W2 / W1 ≦ 10.0, a synergistic relationship between these two relationships is obtained. By virtue of the effect, it is possible to obtain a vibrating element 2 whose CI value is sufficiently suppressed by miniaturization.
By setting L to 2 mm or less, preferably 1 mm or less, a small vibrating element 2 used for an oscillator mounted on a portable music device or an IC card can be obtained. Further, by setting W1 to 100 μm or less, preferably 50 μm or less, it is possible to obtain a vibration element 2 that resonates at a low frequency and is used in an oscillation circuit that achieves low power consumption even in the above range of L.

  In the adiabatic region, when the vibrating arm extends in the Y-axis direction on the Z-cut quartz plate and flexurally vibrates in the X-axis direction, W1 is preferably 12.8 μm or more. When the vibrating arm extends in the axial direction and bends and vibrates in the Y-axis direction, W1 is preferably 14.4 μm or more, and the vibrating arm extends in the Y-axis direction and vibrates in the Z-axis direction with an X-cut quartz plate. In this case, W1 is preferably 15.9 μm or more. By doing so, the heat insulating region can be reliably formed, so that the formation of the grooves 52 and 53 reduces the thermoelastic loss and improves the Q value, and at the same time, in the region where the grooves 52 and 53 are formed. By driving, (the electric field efficiency is high and the driving area can be increased), the CI value decreases.

  In addition, the bank portions (the main surfaces sandwiching the groove 52 along the width direction orthogonal to the longitudinal direction of the vibrating arm) 511a and the grooves of the main surface 512 located on both sides of the groove 52 of the main surface 511 in the X-axis direction. When the width (length in the X-axis direction) of the bank portions 512a located on both sides in the X-axis direction of 53 is W3 [μm], W3 is set to 6 μm or less. Thereby, the equivalent series resistance R1 (CI value) can be sufficiently reduced while maintaining the Q value of the vibrating element 2 relatively high. As a result, it is possible to obtain the vibration element 2 that can exhibit excellent vibration characteristics with low power consumption.

  Here, the grounds for setting the width W3 of the bank portions 511a and 512a to 6 μm or less will be described based on simulation results performed by the inventors. In the following, a simulation using a vibration element 2 having a Z-cut quartz plate patterned and having a bending vibration frequency (mechanical bending vibration frequency) f = 32.768 kHz will be used as a representative example. It has been confirmed that when the bending vibration frequency f is in the range of 32.768 kHz ± 1 kHz, there is almost no difference from the simulation results shown below.

  In this simulation, the vibrating element 2 in which a Z-cut quartz plate (rotation angle 0 °) is patterned by wet etching is used. Therefore, as shown in FIG. 7, the grooves 52 and 53 have a shape in which a crystal plane of quartz crystal appears. FIG. 7 shows a cross section corresponding to a cross section taken along line BB in FIG. Since the etching rate in the −X-axis direction is lower than the etching rate in the + X-axis direction, the side surface in the −X-axis direction has a relatively gentle slope, and the side surface in the + X-axis direction has a near vertical slope.

The size of the vibrating arm 5 of the vibrating element 2 used in this simulation is such that the total length L is 930 μm, the thickness T is 120 μm, the width W1 of the arm 51 is 80 μm, the width W2 of the hammer head 59 is 138 μm, and the hammer head 59 Has a length H of 334 μm. In such a vibration element 2, a simulation was performed by changing the width W3 of the bank portions 511a and 512a.
It has been confirmed by the inventors that even if the total length L, the thickness T, the width W1, the width W2, and the length H are changed, the same tendency as the simulation result shown below is obtained. In this simulation, the vibrating element 2 in which the first and second driving electrodes 84 and 85 were not formed was used.

  FIG. 8 shows the widths W3 and Q of the bank portions 511a and 512a when the maximum depth t of the grooves 52 and 53 is 0.208T, 0.292T, 0.375T, 0.458T, and 0.483T, respectively. FIG. 9 is a graph showing the relationship between the maximum depth t of the grooves 52 and 53 at 0.208T, 0.292T, 0.375T, 0.458T and 0.458T, respectively. 6 is a graph showing the relationship between the width W3 of the bank portions 511a and 512a and the reciprocal of R1 (1 / R1) when .483T is set.

  The graphs shown in FIGS. 8 and 9 are created as follows. First, a Q value is determined by the finite element method considering only thermoelastic loss. Since the Q value has frequency dependence, the obtained Q value is converted to a Q value at 32.768 kHz (Q value after F conversion). FIG. 8 is a graph created by plotting the Q value after the F conversion on the vertical axis and W3 on the horizontal axis. Further, R1 is calculated based on the Q value after the F conversion. Since R1 also has frequency dependence, the obtained R1 was converted to R1 at 32.768 kHz, and the reciprocal thereof was plotted on the vertical axis and W3 was plotted on the horizontal axis. It is a graph shown in FIG. The larger the Q value is, the higher the vibration characteristics of the vibrating element 2 can be. The smaller R1 (1 / R1 increases), the lower the power consumption of the vibrating element 2 can be.

The conversion of the Q value to the Q value after the F conversion can be performed as follows using the above equation (1) and the following equation (3).
Q = {ρCp / (Cα ² H)} × [{1+ (f / fm0) ² } / (f / fm0)]
Ρ (3) where ρ in the formula (3) is the mass density of the vibrating arm 5, Cp is the heat capacity of the vibrating arm 5, C is the elastic stiffness constant of expansion and contraction in the longitudinal direction of the vibrating arm 5, and α is the vibrating arm. 5, the coefficient of thermal expansion in the length direction, H is the absolute temperature, and f is the natural frequency. Note that a is a width (effective width) when it is assumed that the vibrating arm 5 has a flat plate structure (flat plate shape). be able to.

First, the natural frequency of the vibrating arm 5 used in the simulation is set to F1, the obtained Q value is set to Q1, and using the equations (1) and (3), a value of a such that f = F1 and Q = Q1 is satisfied. Find the value. Next, using the obtained a and setting f = 32.768 kHz, a Q value is calculated from the equation (3). The Q value thus obtained is the Q value after the F conversion.
As shown in FIG. 8, the Q value takes a maximum value when the width W3 of the bank portions 511a and 512a is 7 μm, regardless of the depths of the grooves 52 and 53. On the other hand, as shown in FIG. 9, R1 tends to decrease as the width W3 of the bank portions 511a and 512a decreases. The vibrating element is usually designed so that the Q value is as large as possible, that is, the width W3 of the bank portions 511a and 512a is about 7 μm. However, in this case, the power consumption of the vibration element 2 cannot be sufficiently reduced.

  Therefore, in the present invention, the design value of the width W3 of the bank portions 511a and 512a is not intentionally set to the value normally used (7 μm at which the Q value becomes the maximum), and even if the Q value is somewhat sacrificed, the R1 becomes larger. A smaller value (6 μm or less) is preferentially adopted. Thereby, the equivalent series resistance R1 (CI value) can be sufficiently reduced while maintaining the Q value of the vibrating element 2 relatively high. As a result, it is possible to obtain the vibration element 2 that can exhibit excellent vibration characteristics with low power consumption.

  The width W3 of the bank portions 511a and 512a may be 6 μm or less, but is preferably 0.1 μm or more and 6 μm or less, more preferably 0.5 μm or more and 4 μm or less, and is more preferably 1 μm or more and 3 μm or less. Is more preferred. By setting the width W3 in such a range, R1 (CI value) of the vibration element 2 can be further reduced, and the vibration element 2 can be driven with lower power consumption. In addition, it is difficult to form the bank portions 511a and 512a having the width W3 smaller than the above lower limit value, or a very high-precision processing technique is required, so that the cost increases.

  Further, the thickness T of the vibrating arm 5 (arm portion 51) and the maximum depth t of the grooves 52 and 53 satisfy the relationship of 0.458T ≦ t ≦ 0.483T, and the bank portions 511a and 512a. Is expressed as −36.000η + 39.020 ≦ W3 [μm] ≦ 26.000η−15.320 (provided that 0.916 ≦ η ≦ 0.966). It is preferable to satisfy. Thereby, the vibration element 2 exhibiting more excellent vibration characteristics can be obtained.

  In particular, the depth of the grooves 52 and 53, that is, η, is preferably as large as possible, specifically, preferably 0.6 or more, more preferably 0.75 or more, and 0.9 or more. Is more preferred. Thereby, since the formation area of the first and second driving electrodes 84 and 85 can be increased, R1 (CI value) of the vibration element 2 can be further reduced, and the vibration driven with lower power consumption can be achieved. Element 2 can be obtained.

  Since η satisfies the relation of 2t / T, when η is constant, t can be increased as the thickness T of the vibrating arm 5 (crystal substrate 3) is increased. Accordingly, the formation area of the first and second driving electrodes 84 and 85 can be further increased, so that R1 of the vibration element 2 can be further reduced. Specifically, the thickness T of the vibrating arm 5 (quartz substrate 3) is preferably 50 μm or more, more preferably 110 μm or more, and even more preferably 160 μm or more. The upper limit of the thickness T of the vibrating arm 5 is not particularly limited, but is preferably 300 μm or less. When the thickness T of the vibrating arm 5 exceeds the upper limit, the shape asymmetry of the vibrating element 2 tends to increase, depending on the processing conditions (wet etching conditions) of the quartz substrate 3.

  Between the pair of vibrating arms 5 and 6 (arms 51 and 61) as described above, a support arm 71 extending from the base 4 (main body 41) along the center line C1 (Y-axis direction). Is provided. The support arm 71 has a substantially rectangular shape in XY plan view, and the vibration element 2 is fixed to the package 9 via the conductive adhesive 11 by the support arm 71 as shown in FIGS. However, the present invention is not particularly limited, and may be fixed to the package 9 via a metal such as Au. With such a configuration, vibration leakage of the vibration element 2 can be more effectively reduced.

  Further, the support arm 71 has, near the boundary with the base 4, a concave portion 711 having a reduced length (width) along the X-axis direction. Thereby, the resonance frequency of the X common mode in which the vibrating arms 5 and 6 bend and vibrate in the same direction in the XY plane is changed from the resonance frequency of the main mode in which the vibrating arms 5 and 6 bend and vibrate so as to be separated and approach each other. Can be separated. As a result, when the vibration element 2 bends and vibrates in the main mode, the so-called coupled vibration in which the vibration mode generated in the X in-phase mode overlaps with the main mode is less likely to occur, and vibration leakage can be reduced.

  Such a vibrating element 2 can be obtained by processing a quartz substrate by, for example, a wet etching method such as alkali wet etching, a laser beam etching, or a dry etching method such as reactive gas etching. It is preferably obtained by processing by a wet etching method. According to the wet etching method, a quartz substrate can be processed accurately with a simple device.

(package)
The package 9 has a box-shaped base 91 having a concave portion 911 opened on the upper surface, and a plate-shaped lid 92 joined to the base 91 so as to close the opening of the concave portion 911. Such a package 9 has a storage space formed by closing the concave portion 911 with the lid 92, and the vibration element 2 is hermetically stored in this storage space. The vibrating element 2 is fixed to the bottom surface of the concave portion 911 by a support arm 71 via a conductive adhesive 11 in which a conductive filler is mixed with an epoxy-based or acrylic-based resin, for example.
The inside of the storage space may be in a reduced pressure (preferably vacuum) state, or may be filled with an inert gas such as nitrogen, helium, or argon. Thereby, the vibration characteristics of the vibration element 2 are improved.

  The constituent material of the base 91 is not particularly limited, but various ceramics such as aluminum oxide can be used. The constituent material of the lid 92 is not particularly limited, but may be a member having a linear expansion coefficient similar to that of the base 91. For example, when the constituent material of the base 91 is a ceramic as described above, it is preferable to use an alloy such as Kovar. The connection between the base 91 and the lid 92 is not particularly limited. For example, the base 91 and the lid 92 may be connected via an adhesive or by seam welding.

In addition, connection terminals 951 and 961 are formed on the bottom surface of the concave portion 911 of the base 91. Although not shown, the first drive electrode 84 of the vibrating element 2 is drawn out halfway in the Y-axis direction of the support arm 71, and the conductive adhesive 11 is electrically connected to the connection terminal 951 at this portion. Have been. Similarly, although not shown, the second drive electrode 85 of the vibrating element 2 is drawn out halfway in the Y-axis direction of the support arm 71, and at this portion, the connection terminal 961 is connected via the conductive adhesive 11. Is electrically connected to
The connection terminal 951 is electrically connected to an external terminal 953 formed on the bottom surface of the base 91 via a through electrode 952 penetrating the base 91, and the connection terminal 961 is connected to a through electrode penetrating the base 91. It is electrically connected via 962 to an external terminal 963 formed on the bottom surface of the base 91.

  The configuration of the connection terminals 951 and 961, the through electrodes 952 and 962, and the external terminals 953 and 963 is not particularly limited as long as it has conductivity. For example, Cr (chromium), W (tungsten), or the like is used. Can be constituted by a metal film in which respective films such as Ni (nickel), Au (gold), Ag (silver), and Cu (copper) are laminated on the metallized layer (underlayer).

<Second embodiment>
Next, a second embodiment of the vibrator of the present invention will be described.
FIG. 10 is a plan view of a vibrating element included in the vibrator according to the second embodiment of the present invention.
Hereinafter, the resonator according to the second embodiment will be described focusing on the differences from the first embodiment described above, and description of the same items will be omitted.
The vibrator of the second embodiment is the same as the above-described first embodiment except that the configuration of the vibrating element is different. The same components as those in the first embodiment are denoted by the same reference numerals.

  As shown in FIG. 10, the base 4 </ b> A of the vibrating element 2 </ b> A includes a main body 41, a reduced width portion 42 provided on the base end (second end) side of the main body 41, and the vibrating arms 5 and 6. And a reduced width portion 43 provided on the front end (first end) side of the main body portion 41. Such a vibration element 2A is fixed to the package 9 via the conductive adhesives 11, 11 at the main body 41. Therefore, the support arm 71 is omitted.

  The width of the reduced width portion 43 (the length along the X-axis direction) gradually decreases along the center line C1 between the vibrating arms 5 and 6 as the distance from the center of the base 4 (the main body portion 41) increases. The outline (edge) has an arch shape (arc shape). Such a reduced width portion 43 has the same function as the reduced width portion 42. Further, in the present embodiment, the conductive adhesives 11, 11 are arranged along the center line C1, but may be arranged along a direction (X-axis direction) orthogonal to the center line C1.

  According to the second embodiment, the same effects as those of the first embodiment can be exerted. In particular, according to the second embodiment, since the support arm 71 can be omitted, the length (width) of the vibration element 2A along the X-axis direction can be reduced. In addition, the base 4 may not have the reduced width portion 42 and may have only the reduced width portion 43, or may not have the reduced width portion 43 and may have only the reduced width portion 42. .

<Third embodiment>
Next, a third embodiment of the vibrator of the present invention will be described.
FIG. 11 is a plan view of a vibrator according to a third embodiment of the present invention, and FIG. 12 is a cross-sectional view taken along line CC in FIG.
Hereinafter, the vibrator of the third embodiment will be described focusing on differences from the above-described first embodiment, and description of similar items will be omitted.
The vibrator of the third embodiment is the same as the above-described first embodiment except that the configuration of the support portion and the configuration of the package are different. The same components as those in the first embodiment are denoted by the same reference numerals.

As shown in FIG. 11, the supporting portion of the vibration element 2B includes a substantially square frame 72 surrounding the base 4, the vibrating arms 5, 6, and the supporting arm 71B. The distal end of 71B (the end opposite to the base 4) is connected. The frame 72 is a portion to be joined to the package 9B.
As shown in FIG. 12, the package 9B has a box-shaped base 91B having a concave portion 911B opened on the upper surface and a box-shaped lid 92B having a concave portion 921B opened on the lower surface. The vibrating element 2B is fixed to the package 9B by holding and joining the frame body 72 to the outer peripheral portion of the lid 92B. Further, a connection terminal 961 (951) provided on the bottom surface of the concave portion 911B of the base 91B and a predetermined portion of the vibration element 2B are connected by a wire 12 made of, for example, gold.
According to the third embodiment, the same effects as those of the first embodiment can be obtained. In particular, according to the third embodiment, since the vibration element 2B is fixed to the package 9B via the frame 72, this fixing can be performed with high accuracy. Therefore, the size of the vibration element 2B can be increased, and as a result, its R1 can be further reduced.

<Fourth embodiment>
Next, a fourth embodiment of the vibrator of the present invention will be described.
FIG. 13 is a plan view of a vibrating element included in a vibrator according to a fourth embodiment of the present invention.
Hereinafter, the vibrator of the fourth embodiment will be described focusing on the differences from the above-described first to third embodiments, and the description of the same items will be omitted.
The vibrator according to the fourth embodiment is the same as the above-described third embodiment except that the configuration of the support portion is different. The same components as those in the third embodiment are denoted by the same reference numerals.

As shown in FIG. 13, the support portion of the vibration element 2C is a support that extends along the center line C1 on the base end (opposite to the pair of vibration arms 5 and 6) side of the base 4C instead of the support arm 71B. An arm 73 is provided. The support arm 73 is connected to the frame 72. The base 4C has the same configuration as the base 4A of the second embodiment.
According to the fourth embodiment, the same effects as those of the first embodiment can be exerted. In particular, according to the fourth embodiment, since the vibration element 2C is fixed to the package 9 via the frame 72, the fixing can be performed with high accuracy. Therefore, the size of the vibration element 2C can be increased, and as a result, its R1 can be further reduced. Further, according to the fourth embodiment, since the supporting arm 71B can be omitted, the length (width) of the vibration element 2C along the X-axis direction can be reduced.
The support arm 73 may be omitted, and the base 4C may be directly connected to the frame 72. Alternatively, the frame 72 may be omitted, and the vibration element may be attached to the support arm 73 using the conductive adhesive 11. 2C may be fixed to the package 9.

2. Oscillator Next, an oscillator to which the vibration element of the present invention is applied (an oscillator of the present invention) will be described.
FIG. 14 is a sectional view showing a preferred embodiment of the oscillator of the present invention.
The oscillator 10 shown in FIG. 14 has a vibrator 1 and an IC chip 8 for driving the vibrating element 2. Hereinafter, the oscillator 10 will be described focusing on differences from the above-described vibrator, and a description of the same items will be omitted.

  As shown in FIG. 14, the package 9 has a box-shaped base 91 having a concave portion 911 and a plate-shaped lid 92 for closing an opening of the concave portion 911. Further, the concave portion 911 of the base 91 includes a first concave portion 911a opening to the upper surface of the base 91, a second concave portion 911b opening to the bottom surface of the first concave portion 911a, and a third concave portion 911c opening to the bottom surface of the second concave portion 911b. And

Connection terminals 95 and 96 are formed on the bottom surface of the first concave portion 911a. The IC chip 8 is disposed on the bottom surface of the third recess 911c. The IC chip 8 has an oscillation circuit for controlling driving of the vibration element 2. When the vibration element 2 is driven by the IC chip 8, a signal of a predetermined frequency can be taken out.
Further, a plurality of internal terminals 93 electrically connected to the IC chip 8 via wires are formed on the bottom surface of the second concave portion 911b. The plurality of internal terminals 93 are electrically connected to external terminals 94 formed on the bottom surface of the package 9 through vias (not shown) formed in the base 91 and vias and wires (not shown). A terminal electrically connected to the connection terminal 95 and a terminal electrically connected to the connection terminal 96 via a not-shown via or wire are included.
In the configuration of FIG. 14, the configuration in which the IC chip 8 is arranged in the storage space has been described. However, the arrangement of the IC chip 8 is not particularly limited. For example, the outside of the package 9 (the bottom surface of the base 91). May be arranged.

3. Next, an electronic device (an electronic device of the present invention) to which the vibration element of the present invention is applied will be described.
FIG. 15 is a perspective view showing a configuration of a mobile (or notebook) personal computer to which an electronic device including the vibration element of the invention is applied. In this figure, a personal computer 1100 includes a main body 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display unit 2000. The display unit 1106 rotates with respect to the main body 1104 via a hinge structure. It is movably supported. Such a personal computer 1100 incorporates a vibrating element 2 (2A to 2C) that functions as a filter, a resonator, a reference clock, and the like.

  FIG. 16 is a perspective view illustrating a configuration of a mobile phone (including a PHS) to which an electronic device including the vibration element of the invention is applied. In this figure, a mobile phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and a display unit 2000 is arranged between the operation buttons 1202 and the earpiece 1204. Such a mobile phone 1200 incorporates a vibrating element 2 (2A to 2C) that functions as a filter, a resonator, or the like.

  FIG. 17 is a perspective view illustrating a configuration of a digital still camera to which an electronic device including the vibration element according to the invention is applied. In this figure, connection with an external device is also simply shown. Here, a normal camera exposes a silver halide photographic film with an optical image of a subject, whereas a digital still camera 1300 photoelectrically converts an optical image of the subject with an image sensor such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.

  A display unit 2000 is provided on the back of a case (body) 1302 in the digital still camera 1300, and is configured to perform display based on an imaging signal from a CCD. The display unit 2000 displays a subject as an electronic image. Functions as a viewfinder. A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side (back side in the figure) of the case 1302.

  When the photographer checks the subject image displayed on the display unit 2000 and presses the shutter button 1306, the imaging signal of the CCD at that time is transferred and stored in the memory 1308. In the digital still camera 1300, a video signal output terminal 1312 and a data communication input / output terminal 1314 are provided on the side surface of the case 1302. As shown, a television monitor 1430 is connected to the video signal output terminal 1312, and a personal computer 1440 is connected to the input / output terminal 1314 for data communication as necessary. Further, the imaging signal stored in the memory 1308 is output to the television monitor 1430 or the personal computer 1440 by a predetermined operation. Such a digital still camera 1300 incorporates a vibrating element 2 (2A to 2C) that functions as a filter, a resonator, or the like.

  The electronic device provided with the vibration element of the present invention may be, for example, an ink jet type ejection device (for example, a personal computer (mobile personal computer) in FIG. 15, a mobile phone in FIG. 16, a digital still camera in FIG. 17). Inkjet printers), laptop personal computers, televisions, video cameras, video tape recorders, car navigation devices, pagers, electronic organizers (including those with communication functions), electronic dictionaries, calculators, electronic game machines, word processors, workstations, televisions Telephone, crime prevention television monitor, electronic binoculars, POS terminal, medical equipment (for example, electronic thermometer, sphygmomanometer, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish finder, various measuring devices, instruments Class (eg, vehicle, aircraft Gauges of a ship), can be applied to a flight simulator or the like.

4. Moving body Next, a moving body to which the vibration element of the present invention is applied (moving body of the present invention) will be described.
FIG. 18 is a perspective view schematically showing an automobile as an example of the moving object of the present invention. The vibration element 2 is mounted on the automobile 1500. The vibration element 2 (2A to 2C) is a keyless entry, immobilizer, car navigation system, car air conditioner, anti-lock brake system (ABS), airbag, tire pressure monitoring system (TPMS: Tire Pressure Monitoring System), engine The present invention can be widely applied to electronic control units (ECUs) such as a control, a battery monitor of a hybrid vehicle or an electric vehicle, a vehicle body posture control system, and the like.

  As described above, the resonator element, the resonator, the oscillator, the electronic device, and the moving body of the present invention have been described based on the illustrated embodiment. However, the present invention is not limited to this, and the configuration of each unit is the same. Any configuration having a function can be used. Further, other arbitrary components may be added to the present invention. Further, the embodiments may be appropriately combined.

  1, 1B: Vibrator 10: Oscillator 11: Conductive adhesive 12: Wire 2, 2A, 2B, 2C: Vibrating element 3: Crystal substrate 4, 4A, 4C: Base 41: Main body 42, 43 ... Reduced width portion 5 Vibrating arm 51 Arm 511, 512 Main surface 511a, 512a Bank 513, 514 Side surface 52, 53 Groove 59 Hammerhead 6 Vibrating arm 61 Arm 611, 612 Main surface 613 614 ... side surface 62, 63 ... groove 69 ... hammer head 71, 71B, 73 ... support arm 711 ... crooked portion 72 ... frame body 8 ... IC chip 84, 85 ... drive electrode 9 ... package 91, 91B ... base 911, 911B , 921B ... concave portion 911a ... first concave portion 911b ... second concave portion 911c ... third concave portion 92, 92B ... lid 93 ... internal terminal 94 ... external end Child 95, 96 connection terminal 951, 961 connection terminal 952, 962 through electrode 953, 963 external terminal 1100 personal computer 1102 keyboard 1104 body unit 1106 display unit 1200 mobile phone 1202 operation buttons 1204 Earpiece 1206 Mouthpiece 1300 Digital still camera 1302 Case 1304 Light receiving unit 1306 Shutter button 1308 Memory 1312 Video signal output terminal 1314 Input / output terminal 1430 Television monitor 1440 Personal computer 1500 Automotive 2000 Display part L: Total length H: Hammer head length W1, W2, W3: Width t: Depth T: Thickness C1: Center line

Claims (14)

A base including a first end and a second end opposite to the first end in plan view;
The base is provided integrally with the base, and extends along the first direction from the base on the first end side of the base, and is arranged along a second direction orthogonal to the first direction. A pair of vibrating arms,
Each said vibrating arm,
Arms and
A wide portion that is located on the opposite side of the base portion side of the arm portion and has a greater length along the second direction than the arm portion;
Each said vibrating arm,
A pair of main surfaces in a front-to-back relationship,
A bottomed groove provided in each of the main surfaces,
A vibrating element, wherein, on the main surface of each of the arm portions, the width of each part arranged along the second direction with the groove interposed therebetween is 6 μm or less.   The vibrating element according to claim 1, wherein the width is 1 μm or more and 3 μm or less. The maximum depth of the groove is t [μm],
When the thickness of the vibrating arm is T [μm],
The vibrating element according to claim 1, wherein η represented by 2t / T is 0.6 or more.   The vibrating element according to claim 1, wherein the vibrating arm has a thickness of 50 μm or more.   The vibrating element according to claim 1, further comprising a supporting portion that supports the base.   The vibrating element according to claim 5, wherein the support portion includes a support arm extending from the base along the first direction between the pair of vibrating arms.   The vibrating element according to claim 5, wherein the support portion includes a support arm extending from the base on the second end side of the base.   The vibrating element according to claim 6, wherein the supporting portion includes a frame that surrounds at least the base, the vibrating arm, and the supporting arm and is connected to the supporting arm.   The vibrating element according to any one of claims 5 to 8, wherein the supporting portion includes a frame surrounding at least the base and the vibrating arm.   The base has a length along the second direction on at least one of the first end side and the second end side, along a center line between the pair of vibrating arms, The vibrating element according to any one of claims 1 to 9, further comprising a reduced width portion that decreases continuously or stepwise as the distance from the center of the base increases. A vibration element according to any one of claims 1 to 10,
A package on which the vibrating element is mounted. A vibration element according to any one of claims 1 to 10,
An oscillator circuit.   An electronic device comprising the vibration element according to claim 1.   A moving body comprising the vibration element according to claim 1.

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