JP7439852B2 - Vibrating elements, vibrators, oscillators, electronic equipment, and moving objects - Google Patents

Description

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

2. Description of the Related Art Vibration elements using quartz crystal have been conventionally known (for example, see Patent Document 1). Such a vibrating element has excellent frequency-temperature characteristics, and is therefore widely used as a reference frequency source or oscillation source for various electronic devices.
The vibrating element described in Patent Document 1 has a tuning fork shape and includes a base and a pair of vibrating arms extending from the base. Further, each vibrating arm is formed with a pair of grooves that are open to the upper and lower surfaces thereof. Therefore, each vibrating arm has a substantially H-shaped cross section. By forming the vibrating arm into such a shape, thermoelastic loss can be reduced and excellent vibration characteristics can be exhibited. However, in the past, the shape (including size) of the vibrating arm around the groove has not been sufficiently studied.

Utility Model Publication No. 2-32229

An object of the present invention is to provide a vibrating element that can exhibit excellent vibration characteristics with low power consumption, as well as a vibrator, an oscillator, an electronic device, and a moving object that include this vibrating element.

The present invention has been made to solve at least part of the above-mentioned problems, and can be realized as the following application examples.
[Application example 1]
The vibration element of the present invention includes a base including a first end and a second end opposite to the first end in plan view;
provided integrally with the base, extending along the first direction from the base on the first end side of the base, and arranged along a second direction orthogonal to the first direction. a pair of vibrating arms;
Each said vibrating arm is
The arm and
a wide part located on the side opposite to the base side of the arm and having a longer length along the second direction than the arm;
Each said vibrating arm is
A pair of main surfaces that are front and back,
a bottomed groove provided on each of the main surfaces,
In the main surface of each of the arm parts, the width of each part lined up along the second direction with the groove interposed therebetween is 6 μm or less.
Thereby, the equivalent series resistance R1 (CI value) can be made sufficiently low while maintaining the Q value of the vibrating 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 vibrating element of the present invention, it is preferable that the width is 1 μm or more and 3 μm or less.
Thereby, 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 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],
It is preferable that η expressed by 2t/T is 0.6 or more.
As a result, the formation area of the drive electrode can be increased, so that R1 (CI value) of the vibrating element can be further reduced, and the vibrating element can be obtained with lower power consumption.
[Application example 4]
In the vibrating element of the present invention, it is preferable that the vibrating arm has a thickness of 50 μm or more.
Thereby, R1 of the vibration 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.
Thereby, vibration leakage of the vibration element can be reduced more effectively.
[Application example 6]
In the vibrating element of the present invention, it is preferable that the support section includes a support arm extending from the base along the first direction between the pair of vibrating arms.
Thereby, vibration leakage of the vibration element can be reduced more effectively.

[Application example 7]
In the vibrating element of the present invention, it is preferable that the support section includes a support arm extending from the base on the second end side of the base.
Thereby, vibration leakage of the vibration element can be reduced more effectively. Furthermore, since there is no need to provide a support arm between the vibrating arms, the length (width) of the vibrating element in the second direction can be reduced.

[Application example 8]
In the vibrating element of the present invention, it is preferable that the support section includes a frame that surrounds at least the base, the vibrating arm, and the support arm, and is connected to the support arm.
Thereby, the vibrating element can be accurately fixed to, for example, the base of the package via the frame. Therefore, the size of the vibration element can be increased, and as a result, its R1 can be made smaller.

[Application example 9]
In the vibrating element of the present invention, it is preferable that the support section includes a frame surrounding at least the base and the vibrating arm.
Thereby, the vibrating element can be accurately fixed to, for example, the base of the package via the frame. Therefore, the size of the vibration 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 portion has a length along the second direction on at least one of the first end side and the second end side that is between the pair of vibrating arms. It is preferable that the base portion includes a reduced width portion that becomes smaller continuously or stepwise as it moves away from the center of the base portion along the center line of the base portion.
Since the base portion has the reduced width portion, vibration leakage of the vibration element can be effectively suppressed.

[Application example 11]
The vibrator of the present invention includes a vibrating element of the present invention,
A package in which the vibration element is mounted.
This provides a highly reliable vibrator.

[Application example 12]
The oscillator of the present invention includes the vibration element of the present invention,
An oscillation circuit.
This provides a highly reliable oscillator.

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

FIG. 1 is a plan view of a vibrator according to a first embodiment of the present invention. 2 is a sectional view taken along line AA in FIG. 1. FIG. FIG. 3 is a plan view illustrating the principle of reducing vibration leakage. 2 is a sectional view taken along line BB in FIG. 1. FIG. FIG. 3 is a cross-sectional view of a vibrating arm for explaining heat conduction during bending vibration. It is a graph showing the relationship between Q value and f/fm. FIG. 3 is a cross-sectional view showing a vibrating arm formed by wet etching. It is a graph showing the relationship between W3 and Q value. It is a graph showing the relationship between W3 and 1/R1. FIG. 7 is a plan view of a vibrating element included in a vibrator according to a second embodiment of the present invention. FIG. 7 is a plan view of a vibrator according to a third embodiment of the present invention. 12 is a sectional view taken along line CC in FIG. 11. FIG. 7 is a plan view of a vibrating element included in a vibrator according to a fourth embodiment of the present invention. 1 is a cross-sectional view showing a preferred embodiment of an oscillator according to the present invention. 1 is a perspective view showing the configuration of a mobile (or notebook) personal computer to which an electronic device including a vibration element of the present invention is applied. 1 is a perspective view showing the configuration of a mobile phone (including a PHS) to which an electronic device including a vibration element of the present invention is applied. 1 is a perspective view showing the configuration of a digital still camera to which an electronic device including a vibration element of the present invention is applied. 1 is a perspective view schematically showing an automobile as an example of a moving object of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, a vibrating element, a vibrator, an oscillator, an electronic device, and a moving object 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>
FIG. 1 is a plan view of a vibrator according to a 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 diagram illustrating the principle of vibration leakage reduction. 4 is a sectional view taken along line BB in FIG. 1, FIG. 5 is a sectional view of a vibrating arm explaining heat conduction during bending vibration, and FIG. 6 is a graph showing the relationship between 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 Q value, and FIG. 9 is a graph showing the relationship between W3 and 1/R1. In the following, for convenience of explanation, three axes that are orthogonal to each other are referred to as the X axis (electrical axis of the crystal), Y axis (mechanical axis of the crystal), and Z axis (optical axis of the crystal), as shown in FIG. .

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. The vibration element 2 and the package 9 will be described in detail below.
(Vibration element 2)
As shown in FIGS. 1, 2, and 4, the vibration element 2 includes a crystal substrate 3 and first and second driving electrodes 84 and 85 formed on the crystal substrate 3. Note that in FIGS. 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 composed of a Z-cut crystal plate. Thereby, the vibration element 2 can exhibit excellent vibration characteristics. A Z-cut crystal plate is a crystal substrate whose thickness direction is the Z-axis. Although the Z axis preferably coincides with the thickness direction of the crystal substrate 3, it may be slightly inclined with respect to the thickness direction from the viewpoint of reducing frequency temperature changes near room temperature.

That is, when the tilt angle is θ degrees (-5 degrees ≦ θ ≦ 15 degrees), the orthogonal coordinate system consisting of the X axis as the electrical axis of the crystal, the Y axis as the mechanical axis, and the Z axis as the optical axis. With the X-axis as a rotation axis, the Z-axis is tilted by θ degrees so that the +Z side rotates in the -Y direction of the Y-axis, and the Z' axis is the axis that rotates the +Y side in the +Z direction of the Z-axis. When the axis tilted by θ degrees as shown in FIG.

As shown in FIG. 1, the crystal 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 a pair of vibrating arms 5, 6 extending from the base 4. A support arm (support part) 71 extending from the base part 4 is provided on the same side as these parts. 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 that extends in the XY plane and has a thickness in the Z-axis direction. The base portion 4 includes a portion (main body portion 41) that supports and connects the vibrating arms 5 and 6, and a reduced width portion 42 that reduces vibration leakage.

The reduced width portion 42 is provided on the base end (second end) side of the main body portion 41, that is, on the opposite side to the side from which the vibrating arms 5 and 6 extend. Further, the width reduction portion 42 has a width (length along the It gradually decreases as it moves away from the main body 41, and its outline (edge) has an arch shape. By having such a reduced width portion 42, vibration leakage of the vibration element 2 can be effectively suppressed.

A concrete explanation is as follows. In order to simplify the explanation, it is assumed that the shape of the vibration element 2 is symmetrical with respect to a predetermined axis (center line C1) parallel to the Y-axis.
First, as shown in FIG. 3(a), a case where the width reduction part 42 is not provided will be described. When the vibrating arms 5 and 6 are bent and deformed so as to separate from each other, the main body 41 near the vibrating arm 5 is connected to a displacement close to a clockwise rotational movement as shown by the arrow, and the vibration In the main body 41 near where the arm 6 is connected, a displacement similar to a counterclockwise rotational movement occurs as shown by the arrow (However, strictly speaking, this is not a movement that can be called a rotational movement. , for convenience, it is called "close to rotational motion").

Since these displacements in the X-axis direction are directed in opposite directions, they are canceled out at the center of the main body 41 in the X-axis direction, leaving a displacement in the +Y-axis direction (although strictly speaking, the Z-axis direction component directional displacement also remains, but is omitted here). That is, the main body portion 41 undergoes a bending deformation such that the central portion in the X-axis direction is displaced in the +Y-axis direction. A support arm 71 extends from the main body portion 41 having a displacement in the +Y-axis direction, and since the support arm 71 will perform a movement having a displacement in the +Y-axis direction, an adhesive is formed on the support arm 71, When it is fixed to a package via an adhesive, the elastic energy accompanying the displacement in the +Y axis direction leaks to the outside via the adhesive. This is a loss called vibration leakage, which causes a deterioration of the Q value and, as a result, a deterioration of the CI value.

On the other hand, as shown in FIG. 3(b), in the case where the width reduction part 42 is provided, the width reduction part 42 has an arch-shaped (curved) outline, so that the above-mentioned rotation Displacements close to motion will cause them to jam together in the reduced width section 42. That is, at the center portion of the reduced width portion 42 in the X-axis direction, displacement in the X-axis direction is canceled out in the same manner as in the center portion of the main body portion 41 in the X-axis direction, and at the same time, displacement in the Y-axis direction is suppressed. Become. Furthermore, since the width-reducing portion 42 has an arched outline, displacement in the +Y-axis direction that would 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 width-reducing portion 42 is provided is much smaller than when the width-reducing portion 42 is not provided. That is, a vibration element with small vibration leakage can be obtained.

In addition, although the outline of the width reduction part 42 is arch-shaped here, it is not limited to this as long as it exhibits the above-mentioned effect. For example, in a reduced width section, the width decreases stepwise along the center line C1 in a plan view, and the outline is stepped (step-like) formed by a plurality of straight lines; A reduced width part whose outline is formed in a mountain shape (triangular shape) by two straight lines, and whose width is linear (continuous) along the center line C1 in plan view. It may be a reduced width portion or the like whose outline 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. These vibrating arms 5 and 6 each have a longitudinal shape, with their base ends serving as fixed ends and their distal ends serving as free ends. The vibrating arms 5 and 6 are provided at the tips of the arm portions 51 and 61 (on the opposite side to the base portion 4), respectively, and have approximately rectangular hammer heads (arm portions) in the XY plane view. 59, 69 whose length along the X-axis direction is longer than those of 51, 61.

As shown in FIG. 4, the arm portion 51 has a pair of main surfaces 511 and 512 formed by the XY plane, and a pair of side surfaces 513 and 514 formed by the YZ plane and connecting 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, and has a tip located at the boundary between the arm portion 51 and the hammer head 59, and a base end located at the base portion 4. The arm portion 51 has a substantially H-shaped cross section in the portion where the grooves 52 and 53 are formed.

By forming the grooves 52 and 53 in the vibrating arm 5 in this manner, thermoelastic loss can be reduced and excellent vibration characteristics can be exhibited (described in detail 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. By configuring the tips of the grooves 52 and 53 to extend to the hammer head 59, the stress concentration generated around the tips of the grooves 52 and 53 is alleviated, thereby reducing the risk of breakage or chipping that may occur when an impact is applied. Decrease. Alternatively, if the tips of the grooves 52 and 53 are located closer to the base than in this embodiment, the stress concentration generated near the boundary between the arm portion 51 and the hammer head 59 is alleviated, so that the impact is not applied. This reduces the risk of breakage or chipping that may occur.

Furthermore, since the base ends of each groove 52 and 53 extend to the base 4, stress concentration at the boundary between these grooves is alleviated. 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, Since the stress concentration that occurs is alleviated, the risk of breakage or chipping that occurs 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 so that the cross-sectional center of gravity of the vibrating arm 5 coincides with the center of the cross-sectional shape of the vibrating arm 5. Preferably, it is formed. By doing so, unnecessary vibrations (specifically, oblique vibrations having an out-of-plane component) of the vibrating arm 5 are reduced, so that vibration leakage can be reduced. Further, in this case, since the occurrence of unnecessary vibrations is reduced, the drive range is relatively increased and the CI value can be reduced.
Further, it is preferable that the center of the hammer head 59 in the X-axis direction is 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 twisting of 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 formed on the XY plane, and a pair of side surfaces 613 and 614 formed on the YZ plane and connecting 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, has a distal end located at the boundary between the arm portion 61 and the hammer head 69, and a proximal end located on the base portion 4. The arm portion 61 has a substantially H-shaped cross section in the portion where the grooves 62 and 63 are formed.
Further, it is preferable that the center of the hammer head 69 in the X-axis direction is 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 which is caused by the twisting of the vibrating arm 6 during bending vibration, and therefore it is possible to suppress vibration leakage.

As shown in FIG. 4, a pair of first drive electrodes 84 and a pair of second drive 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 one 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, a pair of first drive electrodes 84 and a pair of second drive electrodes 85 are formed on the vibrating arm 6 as well. Specifically, one of the first drive 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 one 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 that they repeatedly approach and separate from each other. do.

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

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

As described above, in the vibrating element 2, the grooves 52, 53, 62, and 63 are formed in the vibrating arms 5 and 6 to reduce thermoelastic loss. This will be specifically explained below 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 drive electrodes 84 and 85. As shown in FIG. 5, during this bending vibration, when the side surface 513 of the arm section 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 on the contracting side of the side surfaces 513 and 514 increases, and the temperature on the expanding side increases. Because of the downward movement, a temperature difference occurs between the side surfaces 513 and 514, that is, inside the arm portion 51. Heat conduction caused by such a temperature difference causes loss of vibrational energy, which lowers the Q value of the vibrating element 2. Energy loss associated with such a decrease in Q value is called thermoelastic loss.

In a vibrating element configured like the vibrating element 2 that vibrates in a bending vibration mode, 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 changes to the thermal relaxation frequency fm. The Q value is the minimum when it matches. This thermal relaxation frequency fm can be determined by fm = 1/(2πτ) (where π is pi and e is Napier's number, then τ is e ^{- )} .

Furthermore, if the thermal relaxation frequency when the vibrating arm 5 is assumed to have a flat plate structure (a structure with a rectangular cross-sectional shape) is fm0, then fm0 can be determined by the following formula.
fm0=πk/(2ρCpa ² ) (1)
In addition, π is pi, 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 constants of the material of the vibrating arm 5 itself (i.e., crystal) are input into the thermal conductivity k, mass density ρ, and heat capacity Cp of equation (1), the thermal relaxation frequency fm0 found can be calculated by This is the value when it is not provided.

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

FIG. 6 is a graph showing the f/fm dependence 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 a curve F1 indicated by a solid line A curve F2 shown in FIG. 3 shows 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, as the thermal relaxation frequency fm decreases as described above, the curve F1 shifts in the frequency decreasing direction with respect to the curve F2. Therefore, if the thermal relaxation frequency is fm1 when a groove is formed in the vibrating arm as in the case of vibrating element 2, then by satisfying the following formula (2), the vibration with the groove formed in the vibrating arm is always satisfied. The Q value of the element is higher than that of a vibrating element in which a groove is not formed in the vibrating arm.

Furthermore, if the relationship is limited to f/fm0>1, a higher Q value can be obtained.
Note that in FIG. 6, the region where f/fm<1 is also referred to as an isothermal region, and in this isothermal region, the Q value increases as f/fm becomes smaller. This is because as the mechanical frequency of the vibrating arm becomes lower (the vibration of the vibrating arm becomes slower), the temperature difference within the vibrating arm becomes less likely to occur as described above. Therefore, at the limit when f/fm approaches 0 (zero), isothermal quasi-static operation occurs, and the thermoelastic loss approaches 0 (zero) without limit. On the other hand, the 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 becomes higher, the temperature rise and temperature effect on each side surface changes faster, and there is no time for heat conduction to occur as described above. Therefore, in the limit when f/fm is made infinitely large, an adiabatic operation occurs and the thermoelastic loss approaches zero. From this, satisfying the relationship f/fm>1 can be said to mean that f/fm is in an adiabatic region.

Note that the constituent material (metal material) of the first and second driving electrodes 84 and 85 has a higher thermal conductivity than the crystal that is the constituent material of the vibrating arms 5 and 6. Heat conduction is actively conducted through the first drive electrode 84, and heat conduction is actively conducted through the second drive electrode 85 in the vibrating arm 6. If such 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 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 driving electrode 84 is formed on the bottom surface of the grooves 62 and 63. It is preferable to prevent or suppress the above-described heat conduction by dividing the electrode 85 into a side surface 613 side and a side surface 614 side. As a result, the relaxation time τ is prevented from becoming short, and a vibrating element 2 having a higher Q value can be obtained.

Next, the relationship between the overall length of the vibrating arms 5 and 6 and the length and width of the hammer heads 59 and 69 will be explained. Since the vibrating arms 5 and 6 have similar configurations, 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 of the vibrating arm 5 (length in the Y-axis direction) 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 0.012<H/L<0.3, and more preferably satisfies the relationship 0.046<H/L<0.223. By satisfying such a relationship, the CI value of the vibrating element 2 can be kept low, resulting in a vibrating element 2 with low vibration loss and excellent vibration characteristics.

Here, in the present embodiment, the vibrating arm 5 is connected to a line segment connecting the base end of the vibrating arm 5 to a location where the side surface 514 is connected to the base 4 and a location where the side surface 513 is connected to the base 4. It is set at a location located at the center of the width (length in the X-axis direction). Furthermore, the free end portion of the arm portion 51 has a tapered shape whose 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 If 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, the vibrating arm 5 has a width of 1 [μm] when the width of the arm portion 51 (length in the X-axis direction) is W1 [μm], and the width (length in the X-axis direction) of the hammer head 59 is W2 [μm]. It is preferable that the relationship .5≦W2/W1≦10.0 is satisfied, and it is more preferable that the relationship 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 (even if it is 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 can be suppressed, and the vibrating element 2 can be miniaturized.

In this way, in the vibrating arm 5, by satisfying the relationship 0.012<H/L<0.3 and the relationship 1.5≦W2/W1≦10.0, the synergy of these two relationships can be achieved. As a result, it is possible to obtain a vibrating element 2 that is miniaturized and has a sufficiently suppressed CI value.
Note that by setting L to 2 mm or less, preferably 1 mm or less, it is possible to obtain a small vibrating element 2 that is used in an oscillator mounted on something such as a portable music device or an IC card. Furthermore, by setting W1 to 100 μm or less, preferably 50 μm or less, it is possible to obtain a vibrating element 2 that resonates at a low frequency and is used in an oscillation circuit that achieves low power consumption even within the above range of L.

In addition, in an adiabatic region, when a Z-cut crystal plate has vibrating arms extending in the Y-axis direction and bending vibration in the X-axis direction, W1 is preferably 12.8 μm or more; When the vibrating arm extends in the axial direction and bendingly 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 an 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 this, the area can be reliably made adiabatic, so the formation of the grooves 52 and 53 reduces thermoelastic loss and improves the Q value, and at the same time the area 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 is lowered.

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

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

Furthermore, in this simulation, a vibration element 2 is used in which a Z-cut crystal plate (rotation angle of 0°) is patterned by wet etching. Therefore, the grooves 52 and 53 have a shape in which crystal planes of quartz appear, as shown in FIG. Note that FIG. 7 shows a cross section corresponding to the BB line cross section in FIG. 1. 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 nearly vertical slope.

Further, the sizes of the vibrating arm 5 of the vibrating element 2 used in this simulation are as follows: the total length L is 930 μm, the thickness T is 120 μm, the width W1 of the arm portion 51 is 80 μm, the width W2 of the hammer head 59 is 138 μm, and the hammer head 59 has a width W1 of 80 μm. The length H is 334 μm. In such a vibration element 2, a simulation was performed while changing the width W3 of the bank portions 511a and 512a.
The inventors have confirmed that even if the overall length L, thickness T, width W1, width W2, and length H are changed, the same tendency as the simulation results shown below will occur. Further, in this simulation, the vibration 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 (Q value after F conversion), and 0.208T, 0.292T, 0.375T, 0.458T, and 0, respectively. 483T is a graph showing the relationship between the width W3 of the bank portions 511a and 512a and the reciprocal of R1 (1/R1).

The graphs shown in FIGS. 8 and 9 are created as follows. First, by using the finite element method, the Q value is determined considering only the thermoelastic loss. Note that since the Q value has frequency dependence, the obtained Q value is converted into a Q value at 32.768 kHz (Q value after F conversion). The graph shown in FIG. 8 was created by plotting the F-converted Q value on the vertical axis and W3 on the horizontal axis. Furthermore, R1 is calculated based on the Q value after F conversion. Note that R1 also has frequency dependence, so 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 to create Figure 9. This is the graph shown in . The larger the Q value, the higher the vibration characteristics of the vibration element 2, and the smaller R1 (1/R1 becomes larger), the lower the power consumption of the vibration element 2.

Note that the conversion of the Q value to the Q value after F conversion can be calculated as follows using the above formula (1) and the following formula (3).
Q={ρCp/(Cα ² H)}×[{1+(f/fm0) ² }/(f/fm0)]
(3)
However, in equation (3), ρ 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 longitudinal direction of the vibrating arm 5. , H is the absolute temperature, and f is the natural frequency. Note that a is the width (effective width) assuming that the vibrating arm 5 has a flat plate structure (flat plate shape), but the value of a can also be used for conversion to a Q value after F conversion. be able to.

First, let the natural frequency of the vibrating arm 5 used in the simulation be F1, let the obtained Q value be Q1, and use equations (1) and (3) to find the value of a such that f=F1 and Q=Q1. Find the value. Next, using the obtained a and setting f=32.768kHz, the Q value is calculated from equation (3). The Q value obtained in this manner becomes the Q value after F conversion.
As shown in FIG. 8, the Q value takes a maximum value when the width W3 of the bank portions 511a, 512a is 7 μm, regardless of the depth of the grooves 52, 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 vibration 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 approximately 7 μm. However, this does not allow the power consumption of the vibration element 2 to be sufficiently reduced.

Therefore, in the present invention, the design value of the width W3 of the bank portions 511a and 512a is not set to the normally adopted value (7 μm where the Q value is maximum), but even if the Q value is sacrificed to some extent, R1 is improved. It was decided to preferentially adopt a smaller value (6 μm or less). Thereby, the equivalent series resistance R1 (CI value) can be made sufficiently low while maintaining the Q value of the vibrating element 2 relatively high. As a result, it is possible to obtain a 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 1 μm or more and 3 μm or less. is even more preferable. By setting the width W3 within such a range, R1 (CI value) of the vibrating element 2 can be made smaller, and the vibrating element 2 can be driven with lower power consumption. Note that it is difficult to form the bank portions 511a and 512a having a width W3 smaller than the lower limit value, or it requires extremely high precision processing technology, resulting in high costs.

Further, the thickness T of the vibrating arm 5 (arm portion 51) and the maximum depth t of the grooves 52, 53 satisfy the relationship 0.458T≦t≦0.483T, and the bank portions 511a, 512a The relationship between the width W3 and η expressed by 2t/T is -36.000η+39.020≦W3 [μm]≦26.000η-15.320 (however, 0.916≦η≦0.966). It is preferable to be satisfied. Thereby, it is possible to obtain a vibration element 2 that exhibits better vibration characteristics.

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

Furthermore, since η satisfies the relationship 2t/T, when η is constant, the larger the thickness T of the vibrating arm 5 (crystal substrate 3), the larger t can be. Thereby, the formation area of the first and second drive electrodes 84 and 85 can be made larger, so that R1 of the vibration element 2 can be further reduced. 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 even more preferably 160 μm or more. Note that 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 (arm parts 51 and 61) as described above, there is a support arm 71 extending from the base part 4 (main body part 41) along the center line C1 (Y-axis direction). It is provided. The support arm 71 has a substantially rectangular shape in an XY plane view, and the vibrating element 2 is fixed to the package 9 by the support arm 71 via a conductive adhesive 11, as shown in FIGS. 1 and 2. However, it 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 reduced more effectively.

Further, the support arm 71 has a constricted portion 711 near the boundary with the base 4, the length (width) of which is reduced along the X-axis direction. As a result, 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 can be released. As a result, when the vibration element 2 is subjected to bending vibration in the main mode, so-called coupled vibration, in which the vibration state 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 crystal substrate by, for example, a wet etching method such as alkali wet etching, a dry etching method such as laser beam etching, or reactive gas etching, but in particular, Preferably, it is obtained by processing using a wet etching method. According to the wet etching method, a crystal substrate can be processed with high precision using a simple device.

(package)
The package 9 includes a box-shaped base 91 having a recess 911 open to the top 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 a recess 911 with a lid 92, and the vibrating element 2 is airtightly stored in this storage space. The vibration element 2 is fixed to the bottom surface of the recess 911 by the support arm 71 via a conductive adhesive 11 made of, for example, an epoxy or acrylic resin mixed with a conductive filler.
Note that 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. 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 preferably a member having a linear expansion coefficient similar to that of the constituent material of the base 91. For example, when the base 91 is made of ceramic as described above, it is preferably made of an alloy such as Kovar. Note that the connection between the base 91 and the lid 92 is not particularly limited, and for example, the base 91 and the lid 92 may be joined via an adhesive, or may be joined by seam welding or the like.

Furthermore, 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 vibration 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 part. 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 this part, the connection terminal 961 is connected via the conductive adhesive 11. 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 that penetrates the base 91. It is electrically connected to an external terminal 963 formed on the bottom surface of the base 91 via a terminal 962 .

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

<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 a vibrator according to a second embodiment of the present invention.
The vibrator of the second embodiment will be described below, focusing on the differences from the first embodiment described above, and descriptions of similar matters will be omitted.
The vibrator of the second embodiment is the same as the first embodiment described above, except for the configuration of the vibrating element. Note that the same components as in the first embodiment described above are given the same reference numerals.

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

The width of the reduced width portion 43 (length along the X-axis direction) gradually decreases as it moves away from the center of the base portion 4 (main body portion 41) along the center line C1 between the vibrating arms 5 and 6, Its outline (edge) is arch-shaped. Such width reduction section 43 has the same function as width reduction section 42 . Further, in this embodiment, the conductive adhesives 11, 11 are arranged along the center line C1, but they may be arranged along the direction (X-axis direction) orthogonal to the center line C1.

This second embodiment can also achieve the same effects as the first embodiment described above. 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. Note that the base 4 may have only the reduced width portion 43 without the reduced width portion 42, or may have only the reduced width portion 42 without the reduced width portion 43. .

<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 sectional view taken along line CC in FIG.
The vibrator of the third embodiment will be described below, focusing on the differences from the first embodiment described above, and descriptions of similar matters will be omitted.
The vibrator of the third embodiment is similar to the first embodiment described above, except that the structure of the support section and the structure of the package are different. Note that the same components as in the first embodiment described above are given the same reference numerals.

As shown in FIG. 11, the support portion of the vibrating element 2B includes a frame 72 having a substantially square outer shape surrounding the base 4, the vibrating arms 5 and 6, and the support arm 71B. The distal end portion (the end opposite to the base portion 4) of 71B is connected. The frame body 72 is a part that is joined to the package 9B.
As shown in FIG. 12, the package 9B includes a box-shaped base 91B having a recess 911B open to the top surface, and a box-shaped lid 92B having a recess 921B open to the bottom surface, Vibration element 2B is fixed to package 9B by sandwiching and joining frame body 72 to the outer circumference of 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 vibration element 2B are connected by a wire 12 made of, for example, gold.
The third embodiment can also achieve the same effects as the first embodiment described above. In particular, according to the third embodiment, since the vibration element 2B is fixed to the package 9B via the frame 72, this fixation can be performed with high precision. Therefore, the size of the vibration element 2B can be increased, and as a result, its R1 can be made smaller.

<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.
The vibrator of the fourth embodiment will be described below, focusing on the differences from the first to third embodiments described above, and descriptions of similar matters will be omitted.
The vibrator of the fourth embodiment is the same as the third embodiment described above except for the configuration of the support section. Note that the same components as in the third embodiment described above are given the same reference numerals.

As shown in FIG. 13, the support portion of the vibrating element 2C is a support extending along the center line C1 at the base end (opposite to the pair of vibrating arms 5 and 6) of the base portion 4C instead of the support arm 71B. An arm 73 is provided. This support arm 73 is connected to the frame 72. Note that the base 4C has the same configuration as the base 4A of the second embodiment.
Such a fourth embodiment can also exhibit the same effects as the first embodiment described above. In particular, according to the fourth embodiment, since the vibrating element 2C is fixed to the package 9 via the frame 72, this fixing can be performed with high precision. 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.
Note that the support arm 73 may be omitted and the base 4C may be directly connected to the frame 72, or 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 (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 includes a vibrator 1 and an IC chip 8 for driving the vibrating element 2. The oscillator 10 will be described below, focusing on the differences from the above-mentioned vibrator, and descriptions of similar matters will be omitted.

As shown in FIG. 14, the package 9 includes a box-shaped base 91 having a recess 911 and a plate-shaped lid 92 that closes the opening of the recess 911. Furthermore, the recess 911 of the base 91 includes a first recess 911a that opens to the top surface of the base 91, a second recess 911b that opens to the bottom of the first recess 911a, and a third recess 911c that opens to the bottom of the second recess 911b. It has

Connection terminals 95 and 96 are formed on the bottom surface of the first recess 911a. Further, the 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 vibration element 2. When the vibration element 2 is driven by the IC chip 8, a signal of a predetermined frequency can be extracted.
Furthermore, a plurality of internal terminals 93 electrically connected to the IC chip 8 via wires are formed on the bottom surface of the second recess 911b. These plurality of internal terminals 93 include terminals that are electrically connected to external terminals 94 formed on the bottom surface of the package 9 via vias (not shown) formed in the base 91, and terminals that are electrically connected to external terminals 94 formed on the bottom surface of the package 9 via vias or wires (not shown). It includes a terminal electrically connected to the connection terminal 95 and a terminal electrically connected to the connection terminal 96 via a via or wire (not shown).
In the configuration of FIG. 14, the IC chip 8 is arranged in the storage space, but the arrangement of the IC chip 8 is not particularly limited. It may be placed in

3. Electronic Device Next, an electronic device to which the vibration element of the present invention is applied (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, a personal computer 1100 includes a main body 1104 including a keyboard 1102 and a display unit 1106 including a display 2000. The display unit 1106 is rotated with respect to the main body 1104 via a hinge structure. movably supported. Such a personal computer 1100 has built-in vibrating elements 2 (2A to 2C) that function as filters, resonators, reference clocks, and the like.

FIG. 16 is a perspective view showing the configuration of a mobile phone (including a PHS) to which an electronic device including the vibration element of the present 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 section 2000 is arranged between the operation buttons 1202 and the earpiece 1204. Such a mobile phone 1200 has built-in vibrating elements 2 (2A to 2C) that function as filters, resonators, and the like.

FIG. 17 is a perspective view showing the configuration of a digital still camera to which an electronic device including the vibration element of the present invention is applied. Note that this diagram also simply shows connections with external devices. Here, while a normal camera exposes a silver halide photographic film to the light image of the subject, the digital still camera 1300 photoelectrically converts the light image of the subject using an image sensor such as a CCD (Charge Coupled Device). Generate an imaging signal (image signal).

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

When the photographer confirms the subject image displayed on the display unit 2000 and presses the shutter button 1306, the CCD imaging signal at that time is transferred and stored in the memory 1308. Further, in this 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. 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 data communication input/output terminal 1314, as necessary. Furthermore, the image pickup signal stored in the memory 1308 is outputted to a television monitor 1430 or a personal computer 1440 by a predetermined operation. Such a digital still camera 1300 has built-in vibrating elements 2 (2A to 2C) that function as filters, resonators, and the like.

Note that, in addition to the personal computer (mobile type personal computer) shown in FIG. 15, the mobile phone shown in FIG. 16, and the digital still camera shown in FIG. inkjet printers), laptop personal computers, televisions, video cameras, video tape recorders, car navigation devices, pagers, electronic notebooks (including those with communication functions), electronic dictionaries, calculators, electronic game devices, word processors, workstations, televisions Telephones, security TV monitors, electronic binoculars, POS terminals, medical equipment (e.g. electronic thermometers, blood pressure monitors, blood sugar meters, electrocardiogram measuring devices, ultrasound diagnostic devices, electronic endoscopes), fish finders, various measuring devices, meters (for example, instruments for vehicles, aircraft, ships), flight simulators, etc.

4. Moving Body Next, a moving body (moving body of the present invention) to which the vibration element of the present invention is applied will be described.
FIG. 18 is a perspective view schematically showing an automobile as an example of a moving object of the present invention. A vibration element 2 is mounted on the automobile 1500. Vibration elements 2 (2A to 2C) are keyless entry, immobilizer, car navigation system, car air conditioner, anti-lock brake 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 vehicles and electric vehicles, and vehicle attitude control systems.

Although the vibrating element, vibrator, oscillator, electronic device, and moving body of the present invention have been described above based on the illustrated embodiments, the present invention is not limited thereto, and the configurations of each part may be the same. It can be replaced with any functional configuration. Moreover, other arbitrary components may be added to the present invention. Further, each embodiment may be combined as appropriate.

1, 1B... Vibrator 10... Oscillator 11... Conductive adhesive 12... Wire 2, 2A, 2B, 2C... Vibration element 3... Crystal substrate 4, 4A, 4C... Base 41... Main body part 42, 43... Width reduction part 5... Vibrating arm 51... Arm part 511, 512... Main surface 511a, 512a... Bank part 513, 514... Side surface 52, 53... Groove 59... Hammer head 6... Vibrating arm 61... Arm part 611, 612... Main surface 613, 614... Side surface 62, 63... Groove 69... Hammer head 71, 71B, 73... Support arm 711... Neck part 72... Frame body 8... IC chip 84, 85... Drive electrode 9... Package 91, 91B... Base 911, 911B , 921B... Recessed part 911a... First recessed part 911b... Second recessed part 911c... Third recessed part 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 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...TV monitor 1440...Personal computer 1500...Car 2000...Display section L...Overall length H...Hammerhead length W1, W2, W3...Width t... Depth T…Thickness C1…Center line

Claims (8)

The base and
a pair of vibrating arms extending along a first direction from one end side of the base and lined up along a second direction orthogonal to the first direction;
including;
One and the other of the pair of vibrating arms, respectively,
The arm and
a wide portion located on the opposite side of the base side of the arm portion and having a longer length along the second direction than the arm portion;
a pair of main surfaces that are along the first direction and the second direction and are in a front-back relationship;
a pair of side surfaces connecting the pair of main surfaces;
provided along the first direction on each of the main surfaces, the tip in the first direction is closer to the base than the boundary between the arm portion and the wide width portion, and the thickness is perpendicular to each of the main surfaces; a bottomed groove portion having a depth along the direction of the width;
including;
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 100 μm or less,
The thickness of the vibrating arm is 110 μm or more and 300 μm or less,
When the maximum depth of the groove is t, and the thickness of the vibrating arm is T,
2t/T≧0.6,
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,
A first bank portion is connected to one of the pair of side surfaces and is lined up with the groove portion along the second direction on the main surface of the vibrating arm in plan view;
A second bank portion is connected to the other of the pair of side surfaces and is lined up with the groove portion along the second direction on the main surface of the vibrating arm in plan view;
The width of the first bank part and the second bank part is 0.1 μm or more and 6 μm or less,
The groove portion includes a first inner surface extending from the first bank portion and a second inner surface extending from the second bank portion,
The first inner surface and the second inner surface have portions that are inclined with respect to the thickness direction,
In the cross section of the arm portion along the second direction, the depth of the groove portion is a distance from the main surface to the intersection of the first inner surface and the second inner surface. Vibration element. In claim 1,
A vibrating element comprising: a support portion disposed on a side opposite to the one end of the base portion. In claim 1 or 2,
When the length of the vibrating arm along the first direction is L, and the length of the wide portion along the first direction is H,
0.012<H/L<0.3
A vibration element characterized by satisfying the following relationship. In any one of claims 1 to 3,
A vibration element characterized in that the widths of the first bank portion and the second bank portion are 1 μm or more and 3 μm or less. The vibration element according to any one of claims 1 to 4,
a package in which the vibration element is housed;
A vibrator characterized by comprising: The vibration element according to any one of claims 1 to 4,
an oscillation circuit;
An oscillator comprising: An electronic device comprising the vibrating element according to any one of claims 1 to 4. A moving body comprising the vibration element according to claim 1 .

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