JP7060073B2 - Vibrating elements, oscillators, oscillators, electronic devices and mobiles - Google Patents

Description

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

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

Jitsukaihei No. 2-322229

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

The present invention has been made to solve at least a part of the above-mentioned problems, and can be realized as the following application examples.
[Application Example 1]
The vibrating element of the present invention includes a first end portion and a base portion including a second end portion opposite to the first end portion in a plan view.
It is provided integrally with the base portion, extends from the base portion along the first direction on the first end side of the base portion, and is arranged along a second direction orthogonal to the first direction. Including a pair of vibrating arms,
Each of the vibrating arms
Arms and
Includes a wide portion of the arm that is located on the opposite side of the base and has a larger length along the second direction than the arm.
Each of the vibrating arms
A pair of main faces that are in a front-to-back relationship,
Including a bottomed groove provided on each of the main surfaces,
The main surface of each of the arms is characterized in that the width of each portion arranged across the groove along the second direction is 6 μm or less.
As a result, the equivalent series resistance R1 (CI value) can be sufficiently lowered while maintaining the Q value of the vibrating element relatively high. As a result, it is possible to obtain a vibration element capable of exhibiting excellent vibration characteristics with low power consumption.

[Application example 2]
In the vibrating element of the present invention, the width is preferably 1 μm or more and 3 μm or less.
As a result, the R1 (CI value) of the vibrating element can be made smaller, and the vibrating element can be driven with lower power consumption.
[Application example 3]
In the vibrating element of the present invention, the maximum depth of the groove is t [μm].
When the thickness of the vibrating arm is T [μm],
It is preferable that η represented by 2t / T is 0.6 or more.
As a result, the forming area of the drive electrode can be increased, so that the R1 (CI value) of the vibrating element can be made smaller, and the vibrating element can be obtained with lower power consumption.
[Application example 4]
In the vibrating element of the present invention, the thickness of the vibrating arm is preferably 50 μm or more.
Thereby, R1 of the vibrating element can be made smaller.

[Application Example 5]
The vibrating element of the present invention preferably includes a support portion that supports the base portion.
This makes it possible to more effectively reduce the vibration leakage of the vibrating element.
[Application example 6]
In the vibrating element of the present invention, the support portion preferably includes a support arm extending from the base portion along the first direction between the pair of vibrating arms.
This makes it possible to more effectively reduce the vibration leakage of the vibrating element.

[Application 7]
In the vibrating element of the present invention, the support portion preferably includes a support arm extending from the base portion on the second end side of the base portion.
This makes it possible to more effectively reduce the vibration leakage of the vibrating element. Further, since it is not necessary 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 vibrating element of the present invention, the support portion preferably includes at least the base portion, the vibrating arm, and a frame body that surrounds the vibrating arm and is connected to the support arm.
As a result, the vibrating element can be accurately fixed to, for example, the base of the package via the frame. Therefore, the size of the vibrating element can be increased, and as a result, its R1 can be made smaller.

[Application 9]
In the vibrating element of the present invention, the support portion preferably includes at least the base portion and a frame body surrounding the vibrating arm.
As a result, the vibrating element can be accurately fixed to, for example, the base of the package via the frame. Therefore, the size of the vibrating element can be increased, and as a result, its R1 can be made smaller.

[Application Example 10]
In the vibrating element of the present invention, the base is located on at least one of the first end side and the second end side, and the length along the second direction is between the pair of vibrating arms. It is preferable to include a narrowed portion along the center line of the base, which is continuously or gradually reduced as the distance from the center of the base is increased.
Since the base portion has a narrowed portion, vibration leakage of the vibrating element can be effectively suppressed.

[Application Example 11]
The oscillator of the present invention includes the vibration element of the present invention and the vibration element of the present invention.
It is characterized by including a package in which the vibration element is mounted.
As a result, a highly reliable oscillator can be obtained.

[Application 12]
The oscillator of the present invention is the vibrating element of the present invention and
It is characterized by including an oscillation circuit.
As a result, a highly reliable oscillator can be obtained.

[Application 13]
The electronic device of the present invention is characterized by including the vibrating element of the present invention.
As a result, a highly reliable electronic device can be obtained.
[Application 14]
The moving body of the present invention is characterized by including the vibrating element of the present invention.
As a result, a highly reliable moving body can be obtained.

It is a top view of the oscillator which concerns on 1st Embodiment of this invention. FIG. 3 is a cross-sectional view taken along the line AA in FIG. It is a top view explaining the principle of vibration leakage reduction. It is sectional drawing BB in FIG. It is sectional drawing of the vibrating arm explaining the heat conduction at the time of bending vibration. It is a graph which shows the relationship between a Q value and f / fm. It is sectional drawing which shows the vibrating arm formed by the 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 the vibration element which the oscillator which concerns on 2nd Embodiment of this invention has. It is a top view of the oscillator which concerns on 3rd Embodiment of this invention. 11 is a cross-sectional view taken along the line CC in FIG. It is a top view of the vibration element which the oscillator which concerns on 4th Embodiment of this invention has. It is sectional drawing which shows the preferable embodiment of the oscillator of this invention. It is a perspective view which shows the structure of the mobile type (or notebook type) personal computer which applied the electronic device provided with the vibration element of this invention. It is a perspective view which shows the structure of the mobile phone (including PHS) to which the electronic device provided with the vibration element of this invention is applied. It is a perspective view which shows the structure of the digital still camera to which the electronic device provided with the vibration element of this invention is applied. It is a perspective view which shows typically the automobile as an example of the moving body of this invention.

Hereinafter, the vibrating element, the vibrator, the oscillator, the electronic device, and the mobile body of the present invention will be described in detail based on the preferred embodiments shown in the drawings.
First, an oscillator to which the vibration element of the present invention is applied (the oscillator of the present invention) will be described.
<First Embodiment>
1 is a plan view of the vibrator according to the first embodiment of the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. 3 is a plan view and a view illustrating 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 a vibrating arm for explaining heat conduction during bending vibration, and FIG. 6 is a graph showing the relationship between the Q value and f / fm. 7 is a cross-sectional view showing a vibrating arm formed by wet etching, FIG. 8 is a graph showing the relationship between W3 and the Q value, and FIG. 9 is a graph showing the 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 referred to as an X axis (electric axis of crystal), a Y axis (mechanical axis of crystal), and a Z axis (optical axis of crystal). ..

1. 1. Oscillator The oscillator 1 shown in FIGS. 1 and 2 has a vibrating element 2 (vibrating element of the present invention) and a package 9 for accommodating the vibrating element 2. Hereinafter, the vibrating element 2 and the package 9 will be described in detail in order.
(Vibration element 2)
As shown in FIGS. 1, 2 and 4, the vibrating element 2 has a crystal substrate 3 and first and second drive electrodes 84 and 85 formed on the crystal substrate 3. In FIGS. 1 and 2, for convenience of explanation, the first and second drive electrodes 84 and 85 are not shown.
The crystal substrate 3 is composed of a Z-cut crystal plate. As a result, the vibrating element 2 can exhibit excellent vibration characteristics. The Z-cut quartz plate is a quartz substrate whose thickness direction is the Z axis. The Z-axis is preferably aligned with the thickness direction of the crystal substrate 3, but may be slightly tilted with respect to the thickness direction from the viewpoint of reducing the frequency temperature change in the vicinity of room temperature.

That is, when the tilt angle is θ degree (-5 degrees ≤ θ ≤ 15 degrees), the Cartesian coordinate system including the X axis as the electric axis of the crystal, the Y axis as the mechanical axis, and the Z axis as the optical axis. With the X-axis as the rotation axis, the Z-axis is tilted by θ degrees so that the + Z side of the Y-axis rotates in the −Y direction, and the Y-axis rotates in the + Z direction of the Z-axis. When the axis tilted by θ degrees is the Y'axis, the thickness is the direction along the Z'axis, and the crystal substrate 3 has a surface including the X axis and the Y'axis as the main surface.

As shown in FIG. 1, the crystal substrate 3 has a base 4, a pair of vibrating arms 5, 6 extending from the base 4 on the tip end (first end) side of the base 4, and vibrating arms 5, 6. In between, a support arm (support portion) 71 extending from the base 4 is provided on the same side as these. Therefore, the base 4, the vibrating arms 5 and 6, and the support arm 71 are integrally formed.
The base 4 has a plate shape having an extension in the XY plane and a thickness in the Z-axis direction. The base portion 4 has a portion (main body portion 41) that supports and connects the vibrating arms 5 and 6 and a narrowed portion 42 that reduces vibration leakage.

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

The specific explanation is as follows. For the sake of simplicity, it is assumed that the shape of the vibrating element 2 is symmetrical with respect to a predetermined axis (center line C1) parallel to the Y axis.
First, as shown in FIG. 3A, a case where the narrowed width portion 42 is not provided will be described. 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 rotational motion occurs in the main body 41 near the vibrating arm 5 to which the vibrating arm 5 is connected, and the vibration occurs. In the main body 41 near where the arm 6 is connected, a displacement close to a counterclockwise rotational motion occurs as shown by the arrow (however, since it is not a motion that can be called a rotational motion in a strict sense). , For the sake of convenience, "close to rotary motion").

Since the X-axis direction components of these displacements are oriented in opposite directions, 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). Displacement in the direction remains, but it is omitted here). That is, the main body portion 41 is bent and deformed so that the central portion in the X-axis direction is displaced in the + Y-axis direction. Since the support arm 71 extends from the main body portion 41 having the displacement in the + Y axis direction and the support arm 71 performs the movement having the displacement in the + Y axis direction, an adhesive is formed on the support arm 71. When fixed to the package via an adhesive, the elastic energy associated with the + Y-axis displacement leaks to the outside via the adhesive. This is a loss called vibration leakage, which causes deterioration of the Q value, resulting in deterioration of the CI value.

On the other hand, as shown in FIG. 3B, when the narrowed portion 42 is provided, the narrowed portion 42 has an arch-shaped (curved) contour, so that the rotation described above is performed. Displacements close to motion will stagger each other at the narrowed portion 42. That is, in the central portion of the narrowed portion 42 in the X-axis direction, the displacement in the X-axis direction is canceled out in the same manner as in the central portion in the X-axis direction 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 narrowed width portion 42 is arched, the displacement in the + Y axis direction that is likely to occur in the main body portion 41 is also suppressed. As a result, the displacement of the central portion of the base 4 in the X-axis direction in the + Y-axis direction when the narrowed portion 42 is provided is much smaller than that in the case where the narrowed portion 42 is not provided. That is, it is possible to obtain a vibration element having a small vibration leakage.

Here, the contour of the narrowed portion 42 has an arch shape, but the present invention is not limited to this as long as it exhibits the above-mentioned action. For example, a narrowed portion in which the width gradually decreases along the center line C1 in a plan view and the contour is formed in a stepped shape (step-like) by a plurality of straight lines, and the width in a plan view is along the center line C1. It becomes smaller linearly (continuously), and the contour is formed in a mountain shape (triangular shape) by two straight lines, and the width is linear (continuous) along the center line C1 in a plan view. It may be a narrowed portion or the like whose contour is formed by three or more straight lines.

The vibrating arms 5 and 6 are aligned 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, the base end thereof is a fixed end, and the tip end is a free end. Further, the vibrating arms 5 and 6 are provided at the arm portions 51 and 61 and the tips of the arm portions 51 and 61 (opposite to the base portion 4), respectively, and have a substantially rectangular hammer head (arm portion) in XY plan view. It has 59, 69, which is a wide portion having a larger 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 formed of an XY plane and a pair of side surfaces 513 and 514 which are formed of a YZ plane and connect the pair of main surfaces 511 and 512. have. Further, the arm portion 51 has a bottomed groove 52 that opens to the main surface 511 and a bottomed groove 53 that opens to the main surface 512. Each of the grooves 52 and 53 extends in the Y-axis direction, the tip thereof is located at the boundary between the arm portion 51 and the hammer head 59, and the base end is located at the base portion 4. Such an arm portion 51 has a substantially H-shaped cross-sectional shape 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, the thermal elastic loss can be reduced and excellent vibration characteristics can be exhibited (detailed later). The lengths of the grooves 52 and 53 are not limited, and the tips of the grooves 52 and 53 may be located at the boundary between the arm portion 51 and the hammer head 59 as in the present embodiment. If the tips of the grooves 52 and 53 are configured to extend to the hammer head 59, the stress concentration generated around the tips of the grooves 52 and 53 is alleviated, so that there is a risk of breakage or chipping when an impact is applied. Decrease. Alternatively, if the tips of the grooves 52 and 53 are configured to be located closer to the base than in the present embodiment, the stress concentration generated near the boundary between the arm 51 and the hammer head 59 is alleviated, so that an impact is applied. The risk of breakage or chipping that occurs at the time is reduced.

Further, since the base ends of the grooves 52 and 53 extend to the base portion 4, the stress concentration at the boundary portion thereof is relaxed. Therefore, the risk of breakage or chipping that occurs when an impact is applied is reduced. Alternatively, if the base ends of the grooves 52 and 53 are located in the Y-axis direction (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 is formed. Since the stress concentration that occurs is alleviated, the risk of breakage or chipping that occurs when an impact is applied is reduced.

In the grooves 52 and 53, 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 so 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, diagonal vibration having an out-of-plane component) is reduced, so that vibration leakage can be reduced. Further, in this case, since it is possible to reduce the occurrence of extra vibration, the drive region can be relatively increased and the CI value can be reduced.
Further, it is preferable to slightly shift the center of the hammer head 59 in the X-axis direction 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 caused by twisting the vibrating arm 5 during bending vibration, so that vibration leakage can be suppressed.

The vibrating 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 made of an XY plane and a pair of side surfaces 613 and 614 which are made of a YZ plane and connect the pair of main surfaces 611 and 612. .. Further, the arm portion 61 has a bottomed groove 62 that opens to the main surface 611 and a bottomed groove 63 that opens to the main surface 612. Each of the grooves 62 and 63 extends in the Y-axis direction, the tip thereof is located at the boundary between the arm portion 61 and the hammer head 69, and the base end is located at the base portion 4. Such an arm portion 61 has a substantially H-shaped cross-sectional shape at a portion where the grooves 62 and 63 are formed.
Further, it is preferable to slightly shift the center of the hammer head 69 in the X-axis direction 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 twisting the vibrating arm 6 during bending vibration, so that vibration leakage can be suppressed.

As shown in FIG. 4, the vibrating arm 5 is formed with a pair of first drive electrodes 84 and a pair of second drive electrodes 85. 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. Further, one of the second driving electrodes 85 is formed on the side surface 513, and the other is formed on the side surface 514. Similarly, the vibrating arm 6 is also formed with a pair of first drive electrodes 84 and a pair of second drive electrodes 85. 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. Further, 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 these 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 repeatedly approach and separate from each other. do.

The configurations of the first and second drive electrodes 84 and 85 are not particularly limited, and are gold (Au), gold alloy, platinum (Pt), aluminum (Al), aluminum alloy, silver (Ag), silver alloy, and the like. Chromium (Cr), Chromium alloy, Nickel (Ni), Nickel alloy, Copper (Cu), Molybdenum (Mo), Niob (Nb), Tungsten (W), Iron (Fe), Titanium (Ti), Cobalt (Co) It can be formed of a metal material such as zinc (Zn) or zirconium (Zr), or a conductive material such as indium tin oxide (ITO).

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

As described above, in the vibrating element 2, the grooves 52, 53, 62, 63 are formed in the vibrating arms 5 and 6 to reduce the thermal elastic loss. Hereinafter, this will be specifically described by taking the vibrating arm 5 as an example.
As described above, the vibrating arm 5 flexes and vibrates in the in-plane direction by applying an alternating voltage between the first and second drive electrodes 84 and 85. As shown in FIG. 5, during this bending vibration, when the side surface 513 of the arm portion 51 contracts, the side surface 514 expands, and conversely, 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), the temperature of the contracting surface side of the side surfaces 513 and 514 rises, and the temperature of the expanding surface side increases. As it descends, a temperature difference occurs between the side surface 513 and the side surface 514, that is, inside the arm portion 51. The heat conduction caused by such a temperature difference causes a loss of vibration energy, which lowers the Q value of the vibration element 2. The energy loss associated with such a decrease in the Q value is called thermoelastic loss.

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

Further, if the heat relaxation frequency when the vibrating arm 5 is regarded as having a flat plate structure (a structure having a rectangular cross-sectional shape) is fm0, fm0 can be obtained by the following equation.
fm0 = πk / (2ρCpa ² ) ‥‥ (1)
In addition, π is the pi, k is the thermal conductivity in the vibration direction of the vibrating arm 5, 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 constants of the material itself (that is, the crystal) of the vibrating arm 5 are input to the thermal conductivity k, the mass density ρ, and the heat capacity Cp of the equation (1), the obtained heat relaxation frequency fm0 has grooves 52 and 53 in the vibrating arm 5. It is the value when it is 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, the heat transfer path for adjusting the temperature difference between the side surfaces 513 and 514 generated during the 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 straight line distance (shortest distance) between them. Therefore, the relaxation time τ becomes longer and the heat relaxation frequency fm becomes lower than in the case where the grooves 52 and 53 are not provided in the vibrating arm 5.

FIG. 6 is a graph showing the f / fm dependence of the Q value of the vibrating element in the bending vibration mode. In the figure, the curve F1 shown 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 shown by a solid line. The curved line F2 shows the case where the groove is not formed in the vibrating arm (when the cross-sectional shape of the connecting arm is rectangular). As shown in the figure, the shapes of the curves F1 and F2 do not change, but the curve F1 shifts in the frequency decrease direction with respect to the curve F2 as the heat relaxation frequency fm decreases as described above. Therefore, if the heat relaxation frequency when a groove is formed in the vibrating arm as in the vibrating element 2 is fm1, the vibration in which the groove is always formed in the vibrating arm by satisfying the following equation (2). The Q value of the element is higher than the Q value of the vibrating element in which the groove is not formed in the vibrating arm.

Further, if the relationship is limited to f / fm0> 1, a higher Q value can be obtained.
In FIG. 6, the region of f / fm <1 is also referred to as an isothermal region, and in this isothermal region, the Q value increases as f / fm decreases. This is because the temperature difference in the vibrating arm as described above becomes less likely to occur as the mechanical frequency of the vibrating arm becomes lower (the vibration of the vibrating arm becomes slower). Therefore, in the limit when f / fm is brought as close as possible to 0 (zero), the isothermal quasi-static operation is performed, and the thermoelastic loss approaches 0 (zero) as much as possible. On the other hand, the region where f / fm> 1 is also referred to as 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 temperature rise on each side surface and the switching of the temperature effect become faster, and the time for heat conduction as described above disappears. Therefore, in the limit when f / fm is increased as much as possible, the thermal elastic loss approaches 0 (zero) as much as possible due to the heat insulating operation. From this, it can be said that satisfying the relationship of f / fm> 1 means that f / fm is in the adiabatic region.

Since the constituent materials (metal materials) of the first and second drive electrodes 84 and 85 have higher thermal conductivity than the crystal which is the constituent material of the vibrating arms 5 and 6, the vibrating arm 5 has a higher thermal conductivity. 1 Heat conduction through the drive electrode 84 is positively performed, and heat conduction through the second drive electrode 85 is positively performed in the vibrating arm 6. If heat conduction through the first and second drive electrodes 84 and 85 is positively performed, the relaxation time τ becomes short. Therefore, in the vibrating arm 5, the first drive electrode 84 is divided into the side surface 513 side and the side surface 514 side at the bottom surface of the grooves 52 and 53, and in the vibrating arm 6, the second drive is performed at the bottom surface of the grooves 62 and 63. It is preferable to prevent or suppress the above-mentioned heat conduction by dividing the electrode 85 into a side surface 613 side and a side surface 614 side. As a result, the vibration element 2 having a higher Q value can be obtained by preventing the relaxation time τ from being shortened.

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 as each other, the vibrating arm 5 will be described as a representative below, 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 of the hammer head 59 (length in the Y-axis direction) 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 a low value, so that the vibrating element 2 has a small vibration loss and excellent vibration characteristics.

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

Further, for the vibrating arm 5, when the width of the arm portion 51 (length in the X-axis direction) is W1 [μm] and the width of the hammer head 59 (length in the X-axis direction) is W2 [μm], 1 It is preferable that the relationship of .5 ≦ W2 / W1 ≦ 10.0 is satisfied, and more preferably 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 secured. Therefore, even if the length H of the hammer head 59 is relatively short (less than 30% of L) as described above, the mass effect of the hammer head 59 can be sufficiently exerted. Therefore, by satisfying the relationship of 1.5 ≦ W2 / W1 ≦ 10.0, the total length L of the vibrating arm 5 can be suppressed, and the vibrating element 2 can be miniaturized.

As described above, in the vibrating arm 5, the synergistic effect of these two relationships is satisfied by satisfying the relationship of 0.012 <H / L <0.3 and the relationship of 1.5 ≦ W2 / W1 ≦ 10.0. Due to the effect, the vibrating element 2 whose CI value is sufficiently suppressed by miniaturization can be obtained.
By setting L to 2 mm or less, preferably 1 mm or less, a small vibration 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 used in an oscillation circuit that realizes low power consumption even in the range of L.

Further, in the adiabatic region, when the vibrating arm extends in the Y-axis direction on the Z-cut crystal plate and flexes and vibrates in the X-axis direction, W1 is preferably 12.8 μm or more, and X on the Z-cut crystal plate. 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 with the X-cut crystal plate and bends and vibrates in the Z-axis direction. In this case, W1 is preferably 15.9 μm or more. By doing so, since the adiabatic region can be surely formed, the thermoelastic loss is reduced and the Q value is improved by forming the grooves 52 and 53, 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 earned), the CI value becomes low.

Further, the bank portions (main surfaces arranged with the groove 52 sandwiched 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 of the 53 in the X-axis direction is W3 [μm], W3 is set to 6 μm or less. As a result, the equivalent series resistance R1 (CI value) can be sufficiently lowered while maintaining the Q value of the vibrating element 2 relatively high. As a result, it is possible to obtain a vibration element 2 capable of exhibiting 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 the simulation results performed by the inventors. In the following, a Z-cut crystal plate is patterned and used as a representative of a simulation using a vibration element 2 having a bending vibration frequency (mechanical bending vibration frequency) f = 32.768 kHz. It has been confirmed that there is almost no difference from the simulation results shown below in the range where the bending vibration frequency f is 32.768 kHz ± 1 kHz.

Further, in this simulation, a vibrating element 2 in which a Z-cut crystal 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 the crystal plane of the crystal appears. Note that FIG. 7 shows a cross section corresponding to the cross section taken along the 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 inclination, and the side surface in the + X axis direction has a nearly vertical inclination.

The size of the vibrating arm 5 of the vibrating element 2 used in this simulation is 930 μm in total length L, 120 μm in thickness T, 80 μm in width W1 of arm 51, 138 μm in width W2 of hammer head 59, and hammer head 59. The length H of is 334 μm. In such a vibrating 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 tendency is the same as the simulation result shown below. Further, in this simulation, the vibrating element 2 in which the first and second drive electrodes 84 and 85 are not formed is used.

FIG. 8 shows the widths W3 and Q of the bank portions 511a and 512a when the maximum depths t of the grooves 52 and 53 are 0.208T, 0.292T, 0.375T, 0.458T and 0.483T, respectively. It is a graph showing the relationship with the value (Q value after F conversion), and FIG. 9 shows the maximum depth t of the grooves 52 and 53 to be 0.208T, 0.292T, 0.375T, 0.458T, 0, respectively. It is a graph which shows the relationship between the width W3 of a bank portion 511a, 512a and the reciprocal of R1 (1 / R1) when it is set to .483T.

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

The conversion of the Q value to the Q value after F conversion can be calculated as follows using the above equation (1) and the following equation (3).
Q = {ρCp / (Cα ² H)} × [{1+ (f / fm0) ² } / (f / fm0)]
‥‥ (3)
However, ρ in the equation (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 length direction of the vibrating arm 5, and α is the length direction of the vibrating arm 5. Thermal expansion rate, H is the absolute temperature, and f is the natural frequency. In addition, a is the width (effective width) that the vibrating arm 5 is considered to have a flat plate structure (flat plate shape), but even if this value of a is used, it is converted to the Q value after F conversion. be able to.

First, the natural frequency of the vibrating arm 5 used in the simulation is F1, the obtained Q value is Q1, and the equations (1) and (3) are used so that f = F1 and Q = Q1. Find the value. Next, the obtained a is used, f = 32.768 kHz, and the Q value is calculated from the equation (3). The Q value thus obtained becomes the Q value after F conversion.
As shown in FIG. 8, the Q value takes the maximum value when the width W3 of the bank portions 511a and 512a is 7 μm regardless of the depth of the grooves 52 and 53. On the other hand, as shown in FIG. 9, R1 tends to become smaller as the width W3 of the bank portions 511a and 512a becomes smaller. 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, with this, the power consumption of the vibrating 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 adopted (7 μm at which the Q value is maximum), and even if the Q value is sacrificed to some extent, R1 is more favorable. It was decided to preferentially adopt a smaller value (6 μm or less). As a result, the equivalent series resistance R1 (CI value) can be sufficiently lowered while maintaining the Q value of the vibrating element 2 relatively high. As a result, it is possible to obtain a vibration element 2 capable of exhibiting 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 1 μm or more and 3 μm or less. Is even more preferable. By setting the width W3 in such a range, the R1 (CI value) of the vibrating element 2 can be made smaller, and the vibrating element 2 can be driven with lower power consumption. It should be noted that it is difficult to form the bank portions 511a and 512a having a width W3 smaller than the above lower limit value, or the processing technique with extremely high accuracy is required, so that the cost is high.

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 are satisfied. Width W3 and η represented by 2t / T have a relationship of −36.000η + 39.020 ≦ W3 [μm] ≦ 26.000η-15.320 (however, 0.916 ≦ η ≦ 0.966). It is preferable to be satisfied. As a result, it is possible to obtain a vibration element 2 that exhibits more excellent vibration characteristics.

In particular, the larger the depth of the grooves 52 and 53, that is, the η is preferable, specifically, it is preferably 0.6 or more, more preferably 0.75 or more, and 0.9 or more. Is even more preferable. As a result, the formed area of the first and second drive electrodes 84 and 85 can be increased, so that the R1 (CI value) of the vibration element 2 can be made smaller, and the vibration driven with lower power consumption can be made. The element 2 can be obtained.

Further, since η satisfies the relationship of 2t / T, when η is constant, the larger the thickness T of the vibrating arm 5 (crystal substrate 3), the larger t can be. As a result, the formed area of the first and second drive electrodes 84 and 85 can be made larger, so that the R1 of the vibrating element 2 can be made even smaller. Specifically, the thickness T of the vibrating arm 5 (crystal substrate 3) is preferably 50 μm or more, more preferably 110 μm or more, and further 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 value, the shape asymmetry of the vibrating element 2 tends to increase, although it depends on the processing conditions (wet etching conditions) of the crystal 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. It is provided. The support arm 71 has a substantially rectangular shape in XY plan view, and the vibrating element 2 is fixed to the package 9 by the support arm 71 via the conductive adhesive 11 as shown in FIGS. 1 and 2. However, the present invention is not particularly limited, and the package 9 may be fixed to the package 9 via a metal such as Au. With such a configuration, it is possible to more effectively reduce the vibration leakage of the vibrating element 2.

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

Such a vibrating element 2 can be obtained by processing a crystal substrate by, for example, a wet etching method such as alkaline 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 recess 911 open on the upper surface, and a plate-shaped lid 92 joined to the base 91 so as to close the opening of the recess 911. Such a package 9 has a storage space formed by closing the recess 911 with the lid 92, and the vibration element 2 is airtightly stored in this storage space. The vibrating element 2 is fixed to the bottom surface of the recess 911 by a support arm 71 via, for example, a conductive adhesive 11 in which a conductive filler is mixed with an epoxy-based or acrylic-based resin.
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. This improves the vibration characteristics of the vibration element 2.

The constituent material of the base 91 is not particularly limited, but various ceramics such as aluminum oxide can be used. Further, the constituent material of the lid 92 is not particularly limited, but it is preferable that the constituent material is a member whose linear expansion coefficient is close to that of the constituent material of the base 91. For example, when the constituent material of the base 91 is ceramics as described above, it is preferable to use an alloy such as Kovar. The joining of the base 91 and the lid 92 is not particularly limited, and may be joined via an adhesive, seam welding, or the like.

Further, connection terminals 951 and 961 are formed on the bottom surface of the recess 911 of the base 91. Although not shown, the first drive electrode 84 of the vibrating element 2 is pulled 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. Has been done. Similarly, although not shown, the second drive electrode 85 of the vibrating element 2 is pulled out halfway in the Y-axis direction of the support arm 71, and at that portion, the connection terminal 961 is interposed via the conductive adhesive 11. Is electrically connected to.
Further, 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 a through electrode penetrating the base 91. It is electrically connected to an external terminal 963 formed on the bottom surface of the base 91 via 962.

The configurations of the connection terminals 951 and 961, the through electrodes 952 and 962 and the external terminals 953 and 963 are not particularly limited as long as they have conductivity, but for example, Cr (chromium), W (tungsten) and the like. It can be composed of a metal film in which each film such as Ni (nickel), Au (gold), Ag (silver), Cu (copper) is laminated on the metallized layer (underlayer) of.

<Second Embodiment>
Next, a second embodiment of the oscillator of the present invention will be described.
FIG. 10 is a plan view of a vibrating element included in the oscillator according to the second embodiment of the present invention.
Hereinafter, the oscillator of the second embodiment will be described mainly on the differences from the first embodiment described above, and the description of the same matters will be omitted.
The oscillator of the second embodiment is the same as that of the first embodiment described above, except that the configuration of the vibrating element is different. The same reference numerals are given to the same configurations as those of the first embodiment described above.

As shown in FIG. 10, the base portion 4A of the vibrating element 2A includes a main body portion 41, a narrowing portion 42 provided on the base end (second end portion) side of the main body portion 41, and vibrating arms 5 and 6. In between, it has a narrowed portion 43 provided on the tip end (first end portion) side of the main body portion 41. Such a vibrating element 2A is fixed to the package 9 at the main body 41 via the conductive adhesives 11 and 11. Therefore, the support arm 71 is omitted.

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

Even with such a second embodiment, the same effect as that of the first embodiment described above can be exhibited. In particular, according to the second embodiment, since the support arm 71 can be omitted, the length (width) of the vibrating element 2A along the X-axis direction can be reduced. The base portion 4 may not have the narrowing portion 42 and may have only the narrowing portion 43, or may not have the narrowing portion 43 and may have only the narrowing portion 42. ..

<Third Embodiment>
Next, a third embodiment of the oscillator of the present invention will be described.
11 is a plan view of the oscillator according to the third embodiment of the present invention, and FIG. 12 is a sectional view taken along line CC in FIG.
Hereinafter, the oscillator of the third embodiment will be described mainly on the differences from the first embodiment described above, and the description of the same matters will be omitted.
The oscillator of the third embodiment is the same as that of the first embodiment described above, except that the configuration of the support portion and the configuration of the package are different. The same reference numerals are given to the same configurations as those of the first embodiment described above.

As shown in FIG. 11, the support portion of the vibrating element 2B includes a frame body 72 having a substantially square outer shape, which surrounds the base 4, the vibrating arms 5, 6 and the support arm 71B, and the support arm is attached to the frame body 72. The tip of 71B (the end opposite to the base 4) is connected. The frame body 72 is a portion joined to the package 9B.
As shown in FIG. 12, the package 9B has a box-shaped base 91B having a recess 911B open to the upper surface and a box-shaped lid 92B having a recess 921B to open to the lower surface, and has an outer peripheral portion of the base 91B and a box-shaped lid 92B. The vibrating element 2B is fixed to the package 9B by sandwiching 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 recess 911B of the base 91B and a predetermined portion of the vibrating element 2B are connected by, for example, a wire 12 made of gold or the like.
Even with such a third embodiment, the same effect as that of the above-mentioned first embodiment can be exhibited. In particular, according to the third embodiment, since the vibrating element 2B is fixed to the package 9B via the frame body 72, this fixing can be performed with high accuracy. Therefore, the size of the vibrating element 2B can be increased, and as a result, its R1 can be made smaller.

<Fourth Embodiment>
Next, a fourth embodiment of the oscillator of the present invention will be described.
FIG. 13 is a plan view of the vibrating element included in the oscillator according to the fourth embodiment of the present invention.
Hereinafter, the oscillator of the fourth embodiment will be described mainly on the differences from the first to third embodiments described above, and the same matters will be omitted.
The oscillator of the fourth embodiment is the same as that of the third embodiment described above, except that the configuration of the support portion is different. The same reference numerals are given to the same configurations as those of the third embodiment described above.

As shown in FIG. 13, the support portion of the vibrating element 2C is a support extending along the center line C1 to the base end (opposite to the pair of vibrating arms 5 and 6) side of the base portion 4C instead of the support arm 71B. An arm 73 is provided. The support arm 73 is connected to the frame body 72. The base 4C has the same configuration as the base 4A of the second embodiment.
Even with such a fourth embodiment, the same effect as that of the first embodiment described above can be exhibited. In particular, according to the fourth embodiment, since the vibrating element 2C is fixed to the package 9 via the frame body 72, this fixing can be performed with high accuracy. Therefore, the size of the vibrating element 2C can be increased, and as a result, its R1 can be made smaller. Further, according to the fourth embodiment, since the support arm 71B can be omitted, the length (width) of the vibrating element 2C along the X-axis direction can be reduced.
The support arm 73 may be omitted and the base portion 4C may be directly connected to the frame body 72, or the frame body 72 may be omitted and the support arm 73 may be connected to the vibration element using the conductive adhesive 11. 2C may be fixed to the package 9.

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

As shown in FIG. 14, the package 9 has a box-shaped base 91 having a recess 911 and a plate-shaped lid 92 that closes the opening of the recess 911. Further, the recesses 911 of the base 91 include a first recess 911a that opens to the upper surface of the base 91, a second recess 911b that opens to the bottom surface of the first recess 911a, and a third recess 911c that opens to the bottom surface of the second recess 911b. And have.

Connection terminals 95 and 96 are formed on the bottom surface of the first recess 911a. Further, an IC chip 8 is arranged on the bottom surface of the third recess 911c. The IC chip 8 has an oscillation circuit for controlling the drive of the vibrating element 2. When the vibrating element 2 is driven by the IC chip 8, a signal having a predetermined frequency can be taken out.
Further, a plurality of internal terminals 93 electrically connected to the IC chip 8 via a wire are formed on the bottom surface of the second recess 911b. These plurality of internal terminals 93 are electrically connected to an external terminal 94 formed on the bottom surface of the package 9 via a via (not shown) formed on the base 91, and via a via or a wire (not shown). A terminal electrically connected to the connection terminal 95 and a terminal electrically connected to the connection terminal 96 via a via or a wire (not shown) 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, but the arrangement of the IC chip 8 is not particularly limited, and for example, the outside of the package 9 (bottom surface of the base 91). It may be arranged in.

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

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

FIG. 17 is a perspective view showing a configuration of a digital still camera to which an electronic device including the vibration element of the present invention is applied. It should be noted that this figure also briefly shows the connection with an external device. Here, while a normal camera exposes a silver salt photographic film to a light image of a subject, the digital still camera 1300 photoelectrically converts the light image of a subject by an image pickup device such as a CCD (Charge Coupled Device). Generates an image pickup signal (image signal).

A display unit 2000 is provided on the back surface of the case (body) 1302 of the digital still camera 1300 to display based on an image pickup signal by a CCD, and the display unit 2000 displays a subject as an electronic image. Functions as a finder. Further, on the front side (back side in the drawing) of the case 1302, a light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided.

When the photographer confirms the subject image displayed on the display unit 2000 and presses the shutter button 1306, the image pickup signal of the CCD at that time is transferred and stored in the memory 1308. Further, in the digital still camera 1300, a video signal output terminal 1312 and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302. Then, as shown in the figure, 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, respectively, as needed. Further, the image pickup 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 has a built-in vibration element 2 (2A to 2C) that functions as a filter, a resonator, and the like.

In addition to the personal computer (mobile personal computer) shown in FIG. 15, the mobile phone shown in FIG. 16, and the digital still camera shown in FIG. 17, the electronic device provided with the vibrating element of the present invention includes, for example, an inkjet ejection device (for example,). Inkjet printer), laptop personal computer, TV, video camera, video tape recorder, car navigation device, pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic game equipment, word processor, workstation, TV Telephone, security TV monitor, electronic binoculars, POS terminal, medical equipment (for example, electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish finder, various measuring devices, instruments It can be applied to a class (for example, a vehicle, an aircraft, a ship's instrument), a flight simulator, and the like.

4. Moving body Next, a moving body to which the vibrating 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 a moving body of the present invention. The vibration element 2 is mounted on the automobile 1500. Vibrating element 2 (2A-2C) includes keyless entry, immobilizer, car navigation system, car air conditioner, anti-lock braking system (ABS), airbag, tire pressure monitoring system (TPMS), engine. It can be widely applied to electronic control units (ECUs) such as controls, battery monitors for hybrid and electric vehicles, and body posture control systems.

The vibrating element, oscillator, oscillator, electronic device, and moving body of the present invention have been described above based on the illustrated embodiment, but the present invention is not limited to this, and the configurations of each part are the same. It can be replaced with any configuration having a function. Further, any other constituents may be added to the present invention. Moreover, you may combine each embodiment as appropriate.

1, 1B ... oscillator 10 ... oscillator 11 ... conductive adhesive 12 ... wire 2, 2A, 2B, 2C ... vibration element 3 ... crystal substrate 4, 4A, 4C ... base 41 ... main body 42, 43 ... narrowed portion 5 ... Vibrating arm 51 ... Arm 511, 512 ... Main surface 511a, 512a ... Bank 513, 514 ... Side 52, 53 ... Groove 59 ... Hammer head 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 ... Constriction 72 ... Frame 8 ... IC chip 84, 85 ... Drive electrode 9 ... Package 91, 91B ... Base 911, 911B , 921B ... Concave 911a ... 1st concave 911b ... 2nd concave 911c ... 3rd concave 92, 92B ... Lid 93 ... Internal terminal 94 ... External terminal 95, 96 ... Connection terminal 951, 961 ... Connection terminal 952, 962 ... Through electrode 953, 963 ... External terminal 1100 ... Personal computer 1102 ... Keyboard 1104 ... Main unit 1106 ... Display unit 1200 ... Mobile phone 1202 ... Operation button 1202 ... 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 ... TV monitor 1440 ... Personal computer 1500 ... Automobile 2000 ... Display L ... Overall length H ... Hammer head length W1, W2, W3 ... Width t ... Depth T ... Thickness C1 ... Center line

Claims (8)

At the base,
A pair of vibrating arms extending along a first direction from one end side of the base and lining up along a second direction orthogonal to the first direction.
Including
The base is
A main body having a width equal to or greater than the length along the second direction of the portion to which the pair of vibrating arms at one end are connected, and the main body portion.
The length along the second direction is continuously or stepwise reduced as the distance from the main body portion toward the opposite side to the one end portion, and the arcuate portion in a plan view is formed. With a narrowed part,
Including
The vibrating arm
Arms and
A wide portion located on the side opposite to the base side of the arm portion and having a larger length along the second direction than the arm portion.
Including
One and the other of the pair of vibrating arms, respectively.
A pair of main surfaces that are along the first direction and the second direction and are in a front-to-back relationship.
A pair of side surfaces connecting the pair of main surfaces and
A bottomed groove portion provided on each of the main surfaces along the first direction and having a depth along the direction of the thickness orthogonal to each of the main surfaces.
Including
The portion connected to one of the pair of side surfaces and aligned with the groove portion along the second direction on the main surface of the vibrating arm in a plan view is defined as the first bank portion.
The portion connected to the other of the pair of side surfaces and aligned with the groove portion along the second direction on the main surface of the vibrating arm in a plan view is defined as a second bank portion.
The length of the vibrating arm along the first direction is 1000 μm or less.
The length of the arm portion along the second direction is 12.8 μm or more and 50 μm or less.
The width of the first bank portion and the second bank portion is 6 μm or less.
When the length of the arm portion along the second direction is W1 and the length of the wide portion along the second direction is W2.
1.6 ≤ W2 / W1 ≤ 7.0
Satisfied with the relationship
Let L be the length of the vibrating arm along the first direction, and follow the first direction of the wide portion.
When the length is H,
0.012 <H / L <0.3
A vibrating element characterized by satisfying the relationship . In claim 1,
Includes a support located on the opposite side of the base from the one end.
The narrowed width portion is a vibrating element characterized in that it is connected to the support portion. In claim 1 or 2 ,
A vibrating element having a width of 1 μm or more and 3 μm or less of the first bank portion and the second bank portion. In any one of claims 1 to 3 ,
A vibrating element having a vibrating arm having a thickness of 50 μm or more and 300 μm or less. The vibrating element according to any one of claims 1 to 4 ,
The package that houses the vibrating element and
An oscillator characterized by containing. The vibrating element according to any one of claims 1 to 4 ,
Oscillator circuit and
An oscillator characterized by containing. An electronic device comprising the vibrating element according to any one of claims 1 to 4 . A moving body including the vibrating element according to any one of claims 1 to 4 .

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