JP2014138414A - Vibration element, vibrator, oscillator, electronic device, and mobile unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration element, a vibrator, an oscillator, an electronic device, and a mobile unit capable of suppressing the occurrence of an unnecessary spurious in the vicinity of a resonance frequency.SOLUTION: A vibration element 1 includes: a vibration part 1; a piezoelectric substrate 2 integrated with the vibration part 21 and including a thick part 22 greater in thickness than the vibration part 21; a first excitation electrode 31 provided on one principal surface of the vibration part 21; a second excitation electrode 32 provided on the other principal surface of the vibration part 21 and facing the first excitation electrode 31; and an extraction electrode 35 extending from the first excitation electrode 31 and led out to one principal surface of the thick part 22. Assuming that, in a plan view of the piezoelectric substrate 2, the area of the first excitation electrode 31 is S1, and the area of a region in which the second excitation electrode 32 and the extraction electrode 35 overlap is S2, then the relationship S2/S1≤0.1 is satisfied.

Description

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

The AT-cut crystal resonator element is a thickness-shear vibration mode of the main vibration to be excited, and is suitable for miniaturization and high frequency, and exhibits a cubic curve with excellent frequency temperature characteristics. Used in many ways.
Patent Document 1 discloses an AT-cut quartz crystal vibrating element having an inverted mesa structure having a thin vibrating portion and a thick portion provided on the entire circumference of the vibrating portion. The AT-cut quartz crystal resonator element of Patent Document 2 has a pair of excitation electrodes provided on both surfaces of the vibration part and a pair of extraction electrodes extending from each excitation electrode. In a plan view of the vibration element, the pair of excitation electrodes have different sizes, and the larger excitation electrode includes the smaller excitation electrode. For this reason, the AT-cut quartz crystal resonator element of Patent Document 2 has a region where the extraction electrode extending from the smaller excitation electrode and the larger excitation electrode overlap each other, and the area of this region is large. This region functions as a vibration region different from the vibration region sandwiched between the pair of excitation electrodes, and causes unnecessary spurious near the resonance frequency.

JP 2004-165743 A JP 2012-253630 A

  An object of the present invention is to provide a vibration element, a vibrator, an oscillator, an electronic device, and a moving body that can reduce generation of unnecessary spurious near the resonance frequency.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following application examples.
[Application Example 1]
The vibration element of the present invention includes a substrate including a first region including a vibration region that vibrates by thickness shear vibration, and a second region that is integrated with the first region and is thicker than the first region.
A first excitation electrode provided on one main surface of the vibrating portion;
A second excitation electrode provided on the other main surface of the vibrating portion and arranged to overlap the first excitation electrode in plan view;
An extraction electrode extending from the first excitation electrode and extending to one main surface of the second region,
In the plan view of the substrate, when the area of the first excitation electrode is S1, and the area of the portion where the second excitation electrode and the extraction electrode overlap is S2, the relationship of S2 / S1 ≦ 0.1 is established. It is characterized by satisfaction.
As a result, it is possible to obtain a vibration element that can reduce the occurrence of unnecessary spurious near the resonance frequency.

[Application Example 2]
In the resonator element according to the aspect of the invention, it is preferable that the length of the overlapping portion along the extending direction of the extraction electrode is 20 μm or less.
Thereby, the resistance of the extraction electrode can be reduced.
[Application Example 3]
In the resonator element according to the aspect of the invention, it is preferable that the first excitation electrode is disposed within the range of the second excitation electrode in a plan view of the substrate.
Thereby, a desired vibration characteristic can be exhibited stably.

[Application Example 4]
In the resonator element according to the aspect of the invention, when the thickness of the substrate is t (mm) and the length of the first excitation electrode along the vibration direction is a (mm),
It is preferable that the relationship −1049t + 57 ≦ a / t ≦ −64.4t + 57 is satisfied.
Thereby, stable vibration characteristics can be obtained.
[Application Example 5]
In the resonator element according to the aspect of the invention, when the thickness of the substrate is t (mm) and the length along the direction orthogonal to the vibration direction of the first excitation electrode is b (mm),
It is preferable to satisfy the relationship −823t + 42 ≦ b / t ≦ −120t + 42.
Thereby, stable vibration characteristics can be obtained.

[Application Example 6]
In the resonator element according to the aspect of the invention, the first region may be spaced apart in the vibration direction, separated from the first outer edge and the second outer edge intersecting the vibration direction, and in a direction orthogonal to the vibration direction, and the vibration direction. Intersecting third and fourth outer edges, and
The second region is provided along the first outer edge, provided with a first thick part provided with a fixing part fixed to an object, provided along the third outer edge, and the first It is preferable to include a second thick part connected to the first thick part.
As a result, the rigidity of the vibration element can be increased, and changes in vibration characteristics and occurrence of unnecessary spurious can be suppressed.
[Application Example 7]
In the resonator element according to the aspect of the invention, it is preferable that the second outer edge and the fourth outer edge are exposed from the second region, respectively.
Thereby, size reduction of a vibration element can be achieved.

[Application Example 8]
In the resonator element according to the aspect of the invention, the substrate may be a crystal axis of quartz, an X axis as an electrical axis, a Y axis as a mechanical axis, and a Z axis as an optical axis, with the X axis as a rotation axis. The axis tilted so that the Z axis rotates in the −Y direction of the Y axis to the + Z side is the Z ′ axis, and the axis tilted so that the Y axis rotates in the + Z direction of the Z axis and the + Y side is rotated is the Y ′ axis. It is preferable that the crystal plate has a plane including the X axis and the Z ′ axis as a main surface and a thickness along a direction along the Y ′ axis.
Thereby, it becomes a vibration element which has the outstanding temperature characteristic.

[Application Example 9]
The vibrator of the present invention includes the vibration element of the present invention,
And a package for housing the vibration element.
Thereby, a highly reliable vibrator is obtained.
[Application Example 10]
The oscillator of the present invention includes the vibration element of the present invention,
And an oscillation circuit for driving the vibration element.
Thereby, a highly reliable oscillator can be obtained.

[Application Example 11]
An electronic apparatus according to the present invention includes the vibration element according to the present invention.
As a result, a highly reliable electronic device can be obtained.
[Application Example 12]
The moving body of the present invention includes the vibration element of the present invention.
Thereby, a mobile body with high reliability is obtained.

1 is a perspective view of a vibration element according to a first embodiment of the present invention. FIG. 2 is a plan view of the vibration element shown in FIG. 1. It is a figure explaining the relationship between an AT cut quartz substrate and the crystal axis of quartz. It is a side view which shows the state which fixed the vibration element shown in FIG. 1 to the target object. It is a graph which shows the relationship between the thickness of a vibration part, and the size of an excitation electrode. It is a graph which shows the relationship between the thickness of a vibration part, and the size of an excitation electrode. FIG. 6 is a perspective view illustrating a modification of the vibration element illustrated in FIG. 1. It is a top view of a vibration element concerning a 2nd embodiment of the present invention. It is a top view of a vibration element concerning a 3rd embodiment of the present invention. It is a top view of a vibration element concerning a 4th embodiment of the present invention. It is a perspective view of the vibration element concerning 5th Embodiment of this invention. It is sectional drawing which shows suitable embodiment of the vibrator | oscillator of this invention. It is sectional drawing which shows suitable embodiment of the oscillator of this invention. 1 is a perspective view illustrating a configuration of a mobile (or notebook) personal computer to which an electronic apparatus of the present invention is applied. It is a perspective view which shows the structure of the mobile telephone (PHS is also included) to which the electronic device of this invention is applied. It is a perspective view which shows the structure of the digital still camera to which the electronic device of this invention is applied. 1 is a perspective view schematically showing an automobile as an example of a moving object of the present invention.

Hereinafter, a resonator element, a vibrator, an oscillator, an electronic device, and a moving body of the present invention will be described in detail based on preferred embodiments shown in the drawings.
1. First, the vibration element of the present invention will be described.
<First Embodiment>
1 is a perspective view of the vibration element according to the first embodiment of the present invention, FIG. 2 is a plan view of the vibration element shown in FIG. 1, and FIG. 3 shows the relationship between the AT-cut quartz substrate and the crystal axis of the crystal. 4 is a side view showing a state in which the vibration element shown in FIG. 1 is fixed to an object, and FIGS. 5 and 6 are graphs showing the relationship between the thickness of the vibration part and the size of the excitation electrode, respectively. FIG. 7 is a perspective view showing a modification of the vibration element shown in FIG.
As illustrated in FIGS. 1 and 2, the vibration element 1 includes a piezoelectric substrate (substrate) 2 and an electrode 3 formed on the piezoelectric substrate 2.

(Piezoelectric substrate)
The piezoelectric substrate 2 is a plate-shaped quartz substrate. Here, the crystal that is the material of the piezoelectric substrate 2 belongs to the trigonal system, and has crystal axes X, Y, and Z orthogonal to each other as shown in FIG. The X axis, the Y axis, and the Z axis are referred to as an electric axis, a mechanical axis, and an optical axis, respectively. The piezoelectric substrate 2 of the present embodiment is a “rotated Y-cut quartz crystal substrate” cut out along a plane obtained by rotating the XZ plane around the X axis by a predetermined angle θ, for example (θ = 35 ° 15 ′). A substrate cut out along a plane rotated only by this is called an AT-cut quartz substrate. By using such a quartz substrate, the vibration element 1 having excellent temperature characteristics is obtained.

However, the piezoelectric substrate 2 is not limited to the AT-cut piezoelectric substrate as long as the thickness-shear vibration can be excited. For example, a BT-cut piezoelectric substrate may be used. In addition to the quartz substrate, various piezoelectric substrates such as lithium niobate and lithium tantalate may be used as the piezoelectric substrate 2.
Hereinafter, the Y axis and the Z axis rotated around the X axis corresponding to the angle θ are referred to as a Y ′ axis and a Z ′ axis. That is, the piezoelectric substrate 2 has a thickness in the Y′-axis direction and has a spread in the XZ ′ plane direction.

  In plan view, the piezoelectric substrate 2 has a long shape in which the direction along the X axis is a long side and the direction along the Z ′ axis is a short side. The piezoelectric substrate 2 has the −X axis direction as the distal end side and the + X axis direction as the proximal end side. When the maximum length L in the direction along the X axis of the piezoelectric substrate 2 is set to W and the maximum width in the direction along the Z ′ axis is set to W, L / W is not particularly limited. It is preferably about 1.4.

  As shown in FIG. 1 and FIG. 2, the piezoelectric substrate 2 is integrated with a vibrating portion (first region) 21 including a thin vibrating region (region in which vibration energy is confined) 219, and the vibrating portion 21. And a thick part (second region) 22 that is thicker than 219. The vibration part 21 can be formed, for example, by forming a concave part on the main surface on the + Y′-axis side of the quartz substrate by wet etching.

  The vibrating part 21 is offset toward the −X axis direction side and the −Z ′ axis direction side with respect to the center of the piezoelectric substrate 2, and a part of the outer edge thereof is exposed from the thick part 22. Here, in the plan view of the vibration element 1, the area of the vibration part 21 is preferably ½ or less of the area of the piezoelectric substrate 2. Thereby, since the thick part 22 which is thicker than the vibration part 21 and has high mechanical strength can be formed sufficiently wide, the rigidity of the vibration part 21 can be sufficiently secured. Therefore, the generation of unnecessary spurious can be effectively reduced.

  The vibration part 21 is spaced apart in the X-axis direction (vibration direction of thickness-shear vibration) and extends in the Z′-axis direction (direction intersecting the X-axis direction) in plan view of the vibration element 1. And a second outer edge 212, and a third outer edge 213 and a fourth outer edge 214 that are spaced apart in the Z′-axis direction and extend in the X-axis direction. Of the first and second outer edges 211 and 212, the first outer edge 211 is located on the + X axis side, and the second outer edge 212 is located on the −X axis side. Of the third and fourth outer edges 213 and 214, the third outer edge 213 is located on the + Z′-axis side, and the fourth outer edge 214 is located on the −Z′-axis side. The third outer edge 213 connects the ends of the first and second outer edges 211 and 212 on the + Z ′ axis side, and the fourth outer edge 214 is the −Z ′ axis side of the first and second outer edges 211 and 212. The ends of are connected.

As shown in FIG. 1, the surface of the thick wall portion 22 (the main surface on the + Y′-axis direction side) protrudes more toward the + Y′-axis direction side than the surface of the vibration portion 21 (the main surface on the + Y′-axis direction side). Is provided. On the other hand, the back surface (the main surface on the −Y ′ axis direction side) of the thick portion 22 is provided on the same plane as the back surface (the main surface on the −Y ′ axis direction side) of the vibration unit 21.
The thick part 22 includes a first thick part 23 disposed along the first outer edge 211 and a second thick part disposed along the third outer edge 213 and connected to the first thick part 23. 24. Therefore, the thick part 22 has a substantially L shape along the vibration part 21. On the other hand, the thick part 22 is not formed along the second outer edge 212 and the fourth outer edge 214 of the vibration part 21, and the second and fourth outer edges 212 and 214 are exposed from the thick part 22. ing. As described above, the thick portion 22 is substantially L-shaped and is not provided along the second outer edge 212 and the fourth outer edge 214, so that the vibration element 1 (vibration portion 21) is kept rigid and the vibration element 1 is small. Can be achieved.

  Here, by providing the first thick part 23 on the + X-axis side with respect to the vibration part 21, compared to the case where it is provided on the −X-axis side, the width of the inclined part 231 (the length in the X-axis direction) to be described later. Can be shortened. Similarly, by providing the second thick portion 24 on the + Z′-axis side with respect to the vibration portion 21, the width (Z′-axis) of the inclined portion 241 to be described later is compared with the case where it is provided on the −Z′-axis side. Direction length) can be shortened. Therefore, according to such a thick portion 22, the vibration element 1 can be downsized.

  The first thick portion 23 is connected to the first outer edge 211, and is connected to an inclined portion (residue portion) 231 whose thickness gradually increases in the + X-axis direction, and an edge of the inclined portion 231 on the + X-axis direction side. And a thick portion main body 232 having a substantially constant thickness. Similarly, the second thick portion 24 is connected to the third outer edge 213 and has an inclined portion (residue portion) 241 that gradually increases in thickness toward the + Z′-axis direction, and the + Z′-axis direction side of the inclined portion 241. And a thick portion main body 242 having a substantially constant thickness connected to the edge. Further, a mount portion 29 is provided on the surface of the thick portion main body 232 of the first thick portion 23, and as shown in FIG. Used to be fixed to the object 92.

(electrode)
The electrode 3 has a pair of excitation electrodes 31 and 32, a pair of pad electrodes 33 and 34, and a pair of extraction electrodes 35 and 36. The excitation electrode (first excitation electrode) 31 is formed on the surface of the vibration region 219. On the other hand, the excitation electrode (second excitation electrode) 32 is disposed on the back surface of the vibration region 219 so as to face the excitation electrode 31. The excitation electrodes 31 and 32 are each substantially rectangular with the X-axis direction as the long side and the Z′-axis direction as the short side.

  The excitation electrodes 31 and 32 have a similar shape, and the excitation electrode 32 on the back side is formed larger than the excitation electrode 31 on the front side. Further, the excitation electrode 31 is included in the excitation electrode 32 in a plan view of the vibration element 1. In other words, the entire region of the excitation electrode 31 is located without the outer edges (contours) of the excitation electrode 32 overlapping each other. Thereby, a desired vibration characteristic can be exhibited stably.

In addition, the excitation electrodes 31 and 32 are arranged so that the centers in the X-axis direction overlap each other in a plan view of the vibration element 1. The excitation electrode 31 is formed on the −Z axis side with respect to the excitation electrode 31. That is, the excitation electrodes 31 and 32 are arranged such that the separation distance D2 between the outer edges 312 and 322 on the −Z axis side is smaller than the separation distance D1 between the outer edges 311 and 321 on the + Z axis side of the excitation electrodes 31 and 32. Is provided.
The pad electrode 33 is formed on the mount portion 29 on the surface of the thick portion main body 232. On the other hand, the pad electrode 34 is formed on the back surface of the thick portion main body 232 so as to face the pad electrode 33.

An extraction electrode 35 extends from the excitation electrode 31, and the excitation electrode 31 and the pad electrode 33 are electrically connected via the extraction electrode 35. The extraction electrode 35 extends from the outer edge 312 facing the third outer edge 213 of the excitation electrode 31, and is extracted to the surface of the thick portion 22 via the inclined portion 241. An extraction electrode 36 extends from the excitation electrode 32, and the excitation electrode 31 and the pad electrode 34 are electrically connected via the extraction electrode 36. The extraction electrode 36 is provided so as not to overlap the extraction electrode 35 through the piezoelectric substrate 2. Thereby, the electrostatic capacitance between the extraction electrodes 35 and 36 can be suppressed. Further, in the plan view of the vibration element 1, the extraction electrodes 35 and 36 do not enter the mount portion 29 more than necessary, and the electrode 3 is formed in the mount portion 29 (particularly the edge portion). There is no region T1. In the present embodiment, the region T1 exists on the distal end side and the proximal end side with the pad electrodes 33 and 34 interposed therebetween. Since the quartz substrate constituting the piezoelectric substrate 2 is light transmissive, by adopting the configuration as described above, the background over the mount portion 29 (behind the vibration element 1) from the back side of the vibration element 1. Side view). Therefore, as shown in FIG. 4, when the adhesive 91 is brought into contact with the mount portion 29, the adhesive 91 can be visually recognized through the vibration element 1, the positioning of the adhesive 91, and the contact area with the adhesive 91. The shape and the like of the adhesive 91 can be accurately controlled.
Such an electrode 3 can be composed of a metal film in which Au (gold) or an alloy containing Au as a main component is laminated on an underlayer such as Cr (chromium) or Ni (nickel).

The configuration of the electrode 3 has been described above. In the vibration element 1, a region (part) T <b> 2 where the second excitation electrode 32 and the extraction electrode 35 overlap is formed in a plan view of the vibration element 1. When the area of the first excitation electrode 31 is S1 and the area of the region T2 is S2, S1 and S2 satisfy the relationship S2 / S1 ≦ 0.1. Thereby, the region T2 can be made sufficiently small, and unnecessary spurious can be further away from the resonance frequency of the vibration element 1. Therefore, the vibration element 1 can stably exhibit excellent vibration characteristics. Specifically, as the inventors infer, the region T2 forms a vibration region different from the original vibration region (the region sandwiched between the excitation electrodes 31 and 32), and unnecessary spurious is generated from this region T2. It is thought to do. Since the unnecessary spurious frequency tends to approach the resonance frequency as the region T2 is larger, the present invention makes the area S2 of the region T2 sufficiently small by satisfying the relationship S2 / S1 ≦ 0.1. Thereby, the unnecessary spurious is further away from the resonance frequency of the vibration element 1. The frequency difference between the unnecessary spurious and the resonance frequency is not particularly limited, but is preferably 1000 ppm or more. Thereby, it becomes the vibration element 1 which can fully exhibit the outstanding vibration characteristic stably. If S2 / S1> 0.1, the area of the region T2 becomes excessive, and unnecessary spurious near the resonance frequency is generated, so that excellent vibration characteristics cannot be exhibited stably.
The vibration element 1 is not particularly limited as long as the relationship of S2 / S1 ≦ 0.1 is satisfied, but it is more preferable that the relationship of S2 / S1 ≦ 0.07 is satisfied, and S2 / S1 ≦ 0.05. It is more preferable to satisfy the following relationship. Thereby, the above can be exhibited more remarkably.

  Next, it is proved based on experimental results that the unnecessary spurious can be sufficiently separated from the resonance frequency by satisfying the relationship of S2 / S1 ≦ 0.1. The size of the piezoelectric substrate 2 of the vibration element 1 used in the experiment is 1 in length (length in the X-axis direction) × width (length in the Z′-axis direction) × thickness (length in the Y′-axis direction). .8 mm x 1.0 mm x 0.050 mm. Moreover, the size of the vibration part 21 is length x width x thickness 1.0 mm x 0.9 mm x 0.002 mm. The size of the excitation electrode 32 is length × width × thickness of 0.36 mm × 0.28 mm × 0.000085 mm. The size of the excitation electrode 31 is length × width × thickness of 0.18 mm × 0.14 mm × 0.000085 mm. Then, four types of samples 1 to 4 in which the excitation electrode 31 was shifted in the Z′-axis direction with respect to the excitation electrode 32 were manufactured. The excitation electrode 31 is positioned on the + Z ′ axis side in the order of sample 1, sample 2, sample 3, and sample 4. For these four types of samples, S2 / S1, and the frequency difference Δf between the unwanted spurious and the resonance frequency were obtained. The results are shown in Table 1 below. In addition, the numerical value shown in Table 1 has shown the average value of ten samples about each sample 1-4.

  From Table 1, it can be seen that those satisfying the relationship of S2 / S1 ≦ 0.1, that is, only Sample 1 satisfies Δf ≧ 1000 ppm, and the unnecessary spurious is sufficiently away from the resonance frequency. From the above experimental results, it was proved that the unnecessary spurious can be sufficiently separated from the resonance frequency by satisfying the relationship of S2 / S1 ≦ 0.1.

  Further, the distance D2 between the outer edges 312 and 322 of the excitation electrodes 31 and 32 described above (that is, the length in the Z′-axis direction of the region T2) is not particularly limited, but is preferably 20 μm or less, and 10 μm or less. It is more preferable that Thereby, since the length of the extraction electrode 35 in the region T2 can be further shortened, the resistance of the extraction electrode 35 can be reduced. Here, when the separation distance D2 is set to 0 (zero), the region T2 is not formed. Therefore, the separation distance D2 is most preferable from the viewpoint of moving the unnecessary spurious away from the resonance frequency. Is preferably not 0 (zero). In manufacturing the vibration element 1, it is conceivable that the formation positions of the excitation electrodes 31 and 32 are deviated from predetermined positions. If the vibration element 1 is viewed in plan, the outer edge 312 of the excitation electrode 31 may be When it protrudes to the + Z′-axis side from 322, the vibration characteristics of the vibration element 1 are significantly changed and the performance is also greatly deteriorated. Therefore, even if the formation positions of the excitation electrodes 31 and 32 are deviated from the predetermined positions, the separation distance D2 so that the outer edge 312 of the excitation electrode 31 does not protrude beyond the outer edge 322 of the excitation electrode 32 toward the + Z ′ axis. Is preferably not 0 (zero).

  Further, the thickness t (mm) of the vibration part 21 is normalized as t (mm) = 1670 (m / s) / vibration frequency (kHz). Further, as shown in Table 2, the lower limit value F1, the upper limit value F2, and the lower limit and upper limit center frequency F3 of the vibration frequency using the same electrode dimensions are set. Further, the thickness of the vibrating portion 21 is standardized as 1670 / F1 = t1, 1670 / F2 = t2, and 1670 / F3 = t3.

  Further, when the length of the first excitation electrode 31 along the X-axis direction is a (mm), a is determined from the vibration frequency. As shown in FIG. 5, t, a, and t3 preferably satisfy the relationship of −1049t3 + 57 ≦ a / t ≦ −64.4t3 + 57. Further, when the length along the Z′-axis direction of the excitation electrode 31 is b (mm), b is determined from the vibration frequency. As shown in FIG. 6, t, b, and t3 preferably satisfy the relationship −823t3 + 42 ≦ b / t ≦ −120t3 + 42. By satisfying these relationships, the vibration element 1 that can stably exhibit excellent vibration characteristics can be obtained.

  If both a / t and b / t are less than the lower limit value, the area of the excitation electrode 31 becomes too small depending on the value of t, and the vibration element 1 is incorporated in the oscillator 100 as described later. In this case, it may be difficult to satisfy the variable characteristics of the oscillator 100. On the other hand, when both a / t and b / t exceed the above upper limit value, depending on the value of t, unnecessary spurious is generated in the vicinity of the resonance frequency, and the vibration element 1 can stably exhibit excellent vibration characteristics. May not be obtained.

  Next, it is proved based on experimental results that unnecessary spurs can be sufficiently separated from the resonance frequency of the vibration element 1 when both a / t and b / t satisfy the above-described relationship. In this experiment, the vibration element 1 under the same conditions except for the size of the sample 1 and the excitation electrode 31 (values of a and b) described above is used, and the sizes of the excitation electrode 31 (values of a and b) are different. Seed samples 5-11 were made. And about these 7 types of samples, the frequency difference (DELTA) f of an unnecessary spurious and a resonant frequency was calculated | required, respectively. The results are shown in Table 3 below. In addition, the numerical value shown in Table 2 has shown the average value of 10 samples about each sample 5-11.

From Table 3, it was proved that the unnecessary spurious can be sufficiently separated from the resonance frequency of the vibration element 1 when both a / t and b / t satisfy the above relationship.
The vibration element 1 has been described above. In the vibration element 1 of the present embodiment, the vibration part 21 is formed by forming a recessed part on the + Y′-axis side of the piezoelectric substrate 2, and the thick-walled part 22 is positioned on the + X-axis side with respect to the vibration part 21. The first thick portion 23 and the second thick portion 24 located on the + Z′-axis side are configured, but the vibration element 1 may be configured so as to be turned upside down. That is, as shown in FIG. 7, the vibrating portion 21 is formed by forming a recessed portion on the −Y′-axis side of the piezoelectric substrate 2, and the thick portion 22 is further on the + X-axis side with respect to the vibrating portion 21. You may be comprised by the 1st thick part 23 located and the 2nd thick part 24 located in the -Z 'axis side. Even with such a configuration, it is possible to achieve the same effect as the present embodiment (particularly, the effect of narrowing the width of the inclined portions 231 and 241).

Second Embodiment
Next, a second embodiment of the resonator element according to the invention will be described.
FIG. 8 is a plan view of the resonator element according to the second embodiment of the invention.
Hereinafter, the resonator element according to the second embodiment will be described focusing on differences from the first embodiment described above, and description of similar matters will be omitted.
The vibration element according to the second embodiment of the present invention is the same as that of the first embodiment described above except that the configuration of the thick portion is different. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment mentioned above.

  As shown in FIG. 8, in the vibration element 1 </ b> A of the present embodiment, the thick portion 22 is further formed on the second outer edge 212 of the vibration portion 21 in addition to the first thick portion 23 and the second thick portion 24. The third thick portion 25 is disposed along the second thick portion 24 and is connected to the second thick portion 24. Therefore, the thick portion 22 has a substantially U shape along the vibrating portion 21. The thick part 22 is not formed along the fourth outer edge 214 of the vibration part 21, and the fourth outer edge 214 is exposed from the thick part 22. Thus, by making the thick portion 22 substantially U-shaped, the vibration element 1 can be reduced in size, and the rigidity of the vibration element 1 (vibration part 21) can be further increased, which is unnecessary. Spurious generation can be effectively prevented.

The third thick portion 25 is connected to the second outer edge 212, and has an inclined portion (residue portion) 251 whose thickness gradually increases in the −X axis direction, and an end edge on the −X axis direction side of the inclined portion 251. A thick portion main body 252 having a substantially constant thickness is provided.
Also according to the second embodiment, the same effects as those of the first embodiment described above can be exhibited.

<Third Embodiment>
Next, a third embodiment of the resonator element according to the invention will be described.
FIG. 9 is a plan view of a resonator element according to the third embodiment of the invention.
Hereinafter, the resonator element according to the third embodiment will be described focusing on differences from the first embodiment described above, and description of similar matters will be omitted.
The vibration element according to the third embodiment of the present invention is the same as the second embodiment described above except that the configuration of the thick portion is different. In addition, the same code | symbol is attached | subjected to the structure similar to 2nd Embodiment mentioned above.

  As shown in FIG. 9, in the vibration element 1 </ b> B according to the present embodiment, the thick portion 22 includes a vibrating portion in addition to the first thick portion 23, the second thick portion 24, and the third thick portion 25. 21 has a fourth thick portion 26 that is disposed along the fourth outer edge 214 and connected to the first and third thick portions 23 and 25. Therefore, the thick part 22 has a substantially square shape along the entire circumference of the vibration part 21, and the outer edge of the vibration part 21 is not exposed from the thick part 22. Thus, by making the thick part 22 into a substantially square shape, the rigidity of the vibration element 1 (vibration part 21) can be further increased, and the occurrence of unnecessary spurious can be effectively prevented.

The fourth thick portion 26 is connected to the fourth outer edge 214 and has an inclined portion (residue portion) 261 whose thickness gradually increases in the −Z′-axis direction, and an end of the inclined portion 261 on the −Z′-axis direction side. A thick portion main body 262 having a substantially constant thickness connected to the edge is provided.
Also according to the third embodiment, the same effects as those of the first embodiment described above can be exhibited.

<Fourth embodiment>
Next, a fourth embodiment of the resonator element according to the invention will be described.
FIG. 10 is a plan view of a resonator element according to the fourth embodiment of the invention.
Hereinafter, the vibration element according to the fourth embodiment will be described focusing on the differences from the first embodiment described above, and description of similar matters will be omitted.
The vibration element according to the fourth embodiment of the present invention is the same as that of the third embodiment described above except that the configuration of the thick portion is different. In addition, the same code | symbol is attached | subjected to the structure similar to 3rd Embodiment mentioned above.

As shown in FIG. 10, in the vibration element 1C of the present embodiment, the third thick portion 25 is omitted from the third embodiment described above. That is, the thick part 22 has a first thick part 23, a second thick part 24, and a fourth thick part 26. Therefore, the thick part 22 has a substantially U shape along the vibration part 21, and the second outer edge 212 of the vibration part 21 is exposed from the thick part 22. Thus, by making the thick portion 22 substantially U-shaped, the vibration element 1 can be reduced in size, and the rigidity of the vibration element 1 (vibration part 21) can be further increased, which is unnecessary. Spurious generation can be effectively prevented.
According to the fourth embodiment, the same effect as that of the first embodiment described above can be exhibited.

<Fifth Embodiment>
Next, a fifth embodiment of the resonator element according to the invention will be described.
FIG. 11 is a perspective view of a resonator element according to the fifth embodiment of the invention.
Hereinafter, the resonator element according to the fifth embodiment will be described focusing on differences from the first embodiment described above, and description of similar matters will be omitted.
The vibration element according to the fifth embodiment of the present invention is the same as that of the first embodiment described above except that the configuration of the vibration unit is different. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment mentioned above.

As shown in FIG. 11, in the vibration element 1 </ b> D of the present embodiment, the vibration part 21 is formed by forming recesses on both main surfaces of the piezoelectric substrate 2. In other words, the surface of the thick portion 22 (the main surface on the + Y′-axis direction side) is provided so as to protrude to the + Y′-axis direction side from the surface of the vibration portion 21 (the main surface on the + Y′-axis direction side). The back surface (the main surface on the −Y′-axis direction side) of the thick wall portion 22 is provided so as to protrude to the −Y′-axis direction side from the back surface (the main surface on the −Y′-axis direction side) of the vibration unit 21. Yes. In this manner, by forming the recessed portions on both main surfaces of the piezoelectric substrate 2 to form the vibrating portion 21, for example, the etching depth of the recessed portions can be made shallower than in the first embodiment described above. Can do. Therefore, etching can be performed with higher accuracy, and the outer shape of the piezoelectric substrate 2 can be obtained with higher accuracy.
According to the fifth embodiment, the same effect as that of the first embodiment described above can be exhibited.

2. Next, a vibrator (the vibrator of the present invention) to which the above-described vibration element 1 is applied will be described.
FIG. 12 is a cross-sectional view showing a preferred embodiment of the vibrator of the present invention.
A vibrator 10 illustrated in FIG. 12 includes the above-described vibration element 1 and a package 4 that houses the vibration element 1.

(package)
The package 4 includes a box-shaped base 41 having a concave portion 411 that opens to the upper surface, and a plate-shaped lid 42 that closes the opening of the concave portion 411 and is joined to the base 41. The vibration element 1 is stored in the storage space S formed by closing the recess 411 with the lid 42. The storage space S may be in a reduced pressure (vacuum) state or may be filled with an inert gas such as nitrogen, helium, or argon.

  The constituent material of the base 41 is not particularly limited, but various ceramics such as aluminum oxide can be used. The constituent material of the lid 42 is not particularly limited, but may be a member whose linear expansion coefficient approximates that of the constituent material of the base 41. For example, when the constituent material of the base 41 is ceramic as described above, an alloy such as Kovar is preferable. In addition, joining of the base 41 and the lid 42 is not specifically limited, For example, you may join via an adhesive agent and may join by seam welding etc.

Connection electrodes 451 and 461 are formed on the bottom surface of the recess 411 of the base 41. External mounting terminals 452 and 462 are formed on the lower surface of the base 41. The connection electrode 451 is electrically connected to the external mounting terminal 452 through a through electrode (not shown) formed in the base 41, and the connection electrode 461 is externally connected through a through electrode (not shown) formed in the base 41. The mounting terminal 462 is electrically connected.
The configurations of the connection electrodes 451 and 461 and the external mounting terminals 452 and 462 are not particularly limited as long as they have electrical conductivity. For example, a metallized layer such as Cr (chrome) or W (tungsten) (lower It can be constituted by a metal film in which each film such as Ni (nickel), Au (gold), Ag (silver), Cu (copper), etc. is laminated on the (layer).

The vibration element 1 housed in the housing space S is fixed to the base 41 by the conductive adhesive 51 in the mount portion 29 with the surface facing the base 41 side. The conductive adhesive 51 is provided in contact with the connection electrode 451 and the pad electrode 33. Thereby, the connection electrode 451 and the pad electrode 33 are electrically connected via the conductive adhesive 51. By supporting the vibration element 1 at one place (one point) using the conductive adhesive 51, for example, stress generated in the vibration element 1 due to a difference in thermal expansion coefficient between the base 41 and the piezoelectric substrate 2 can be suppressed. .
The conductive adhesive 51 is not particularly limited as long as it has conductivity and adhesiveness. For example, a conductive filler is added to an adhesive such as silicone, epoxy, acrylic, polyimide, or bismaleimide. A dispersed product can be used.

  The pad electrode 34 of the vibration element 1 is electrically connected to the connection electrode 461 through the bonding wire 52. As described above, since the pad electrode 34 is disposed to face the pad electrode 33, the pad electrode 34 is located immediately above the conductive adhesive 51 in a state where the vibration element 1 is fixed to the base 41. Therefore, leakage of vibration (ultrasonic vibration) applied to the pad electrode 34 during wire bonding can be suppressed, and the bonding wire 52 can be more reliably connected to the pad electrode 34.

3. Next, an oscillator to which the vibrator of the present invention is applied (the oscillator of the present invention) will be described.
FIG. 13 is a cross-sectional view showing a preferred embodiment of the oscillator of the present invention.
An oscillator 100 illustrated in FIG. 13 includes a vibrator 10 and an IC chip 110 for driving the vibration element 1. Hereinafter, the oscillator 100 will be described with a focus on differences from the above-described vibrator, and description of similar matters will be omitted.

  As shown in FIG. 13, in the oscillator 100, the IC chip 110 is fixed to the recess 411 of the base 41. The IC chip 110 is electrically connected to a plurality of internal terminals 120 formed on the bottom surface of the recess 411. The plurality of internal terminals 120 include those connected to the connection electrodes 451 and 461 and those connected to the external mounting terminals 452 and 462. The IC chip 110 has an oscillation circuit for controlling the driving of the vibration element 1. When the vibration element 1 is driven by the IC chip 110, a signal having a predetermined frequency can be extracted.

4). Next, an electronic device (an electronic device of the present invention) to which the vibrator of the present invention is applied will be described.
FIG. 14 is a perspective view showing the configuration of a mobile (or notebook) personal computer to which the electronic apparatus of the present invention is applied. In this figure, a personal computer 1100 includes a main body portion 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display portion 2000. The display unit 1106 rotates with respect to the main body portion 1104 via a hinge structure portion. It is supported movably. Such a personal computer 1100 has a built-in vibrator 10 (vibrating element 1) that functions as a filter, a resonator, a reference clock, and the like.

  FIG. 15 is a perspective view showing a configuration of a mobile phone (including PHS) to which the electronic apparatus of the invention is applied. In this figure, a cellular phone 1200 includes a plurality of operation buttons 1202, a earpiece 1204, and a mouthpiece 1206, and a display unit 2000 is disposed between the operation buttons 1202 and the earpiece 1204. Such a cellular phone 1200 has a built-in vibrator 10 (vibrating element 1) that functions as a filter, a resonator, or the like.

  FIG. 16 is a perspective view showing a configuration of a digital still camera to which the electronic apparatus of the present invention is applied. In this figure, connection with an external device is also simply shown. Here, an ordinary camera sensitizes a silver halide photographic film with a light image of a subject, whereas a digital still camera 1300 photoelectrically converts a light image of a subject with an imaging device such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.

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

  When the photographer confirms the subject image displayed on the display unit and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory 1308. 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. 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 as necessary. Further, the imaging signal stored in the memory 1308 is output to the television monitor 1430 or the personal computer 1440 by a predetermined operation. Such a digital still camera 1300 has a built-in vibrator 10 (vibrating element 1) that functions as a filter, a resonator, or the like.

  In addition to the personal computer (mobile personal computer) shown in FIG. 14, the mobile phone shown in FIG. 15, 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 Telephone, crime prevention 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 detector, various measuring devices, instruments Class (eg, vehicle, aircraft) Gauges of a ship), can be applied to a flight simulator or the like.

5. Next, a moving body (moving body of the present invention) to which the vibrator of the present invention is applied will be described.
FIG. 17 is a perspective view schematically showing an automobile as an example of the moving object of the present invention. The automobile 1500 is equipped with the vibrator 10 (the vibration element 1). The vibrator 10 includes a keyless entry, an immobilizer, a car navigation system, a car air conditioner, an anti-lock brake system (ABS), an air bag, a tire pressure monitoring system (TPMS), an engine control, a hybrid vehicle, The present invention can be widely applied to electronic control units (ECUs) such as battery monitors for electric vehicles, vehicle body posture control systems, and the like.

  As described above, the resonator element, the vibrator, the oscillator, the electronic device, and the moving body of the present invention have been described based on the illustrated embodiment. However, the present invention is not limited to this, and the configuration of each part is the same. It can be replaced with any configuration having the above function. In addition, any other component may be added to the present invention. Moreover, you may combine each embodiment mentioned above suitably.

  DESCRIPTION OF SYMBOLS 1, 1A, 1B, 1C, 1D ... Vibration element 10 ... Vibrator 100 ... Oscillator 110 ... IC chip 120 ... Internal terminal 2 ... Piezoelectric substrate 21 ... Vibrating part 211 ... 1st outer edge 212 ... 2nd outer edge 213 ... 3rd outer edge 214 ... 4th outer edge 219 ... Vibration region 22 ... Thick part 23 ... 1st thick part 231 ... Inclined part 232 ... Thick part main body 24 ... 2nd thick part 241 ... Inclined part 242 ... Thick part main part 25 ... Third thick part 251 ... Inclined part 252 ... Thick part main body 26 ... Fourth thick part 261 ... Inclined part 262 ... Thick part main body 29 ... Mount part 3 ... Electrode 31, 32 ... Excitation electrode 311, 312, 321 322: outer edge 33, 34 ... pad electrode 35, 36 ... extraction electrode 91 ... adhesive 92 ... object 4 ... package 41 ... base 411 ... recess 42 ... lid 451, 461 ... Connection electrode 452, 462 ... External mounting terminal 51 ... Conductive adhesive 52 ... Bonding wire 1100 ... Personal computer 1102 ... Keyboard 1104 ... Main body 1106 ... Display unit 1200 ... Mobile phone 1202 ... Operation button 1204 ... Earpiece 1206 ... Transmission 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 unit D1, D2 ... Separation distance L ... Maximum length T1, T2 ... Area S ... Storage space W ... Maximum width

Claims (12)

A substrate including a first region including a vibration region that vibrates due to thickness shear vibration, and a second region that is integrated with the first region and is thicker than the first region;
A first excitation electrode provided on one main surface of the vibrating portion;
A second excitation electrode provided on the other main surface of the vibrating portion and arranged to overlap the first excitation electrode in plan view;
An extraction electrode extending from the first excitation electrode and extending to one main surface of the second region,
In the plan view of the substrate, when the area of the first excitation electrode is S1, and the area of the portion where the second excitation electrode and the extraction electrode overlap is S2, the relationship of S2 / S1 ≦ 0.1 is established. A vibration element characterized by being satisfied.   The vibration element according to claim 1, wherein a length of the overlapping portion along a direction in which the extraction electrode extends is 20 μm or less.   3. The resonator element according to claim 1, wherein the first excitation electrode is disposed within a range of the second excitation electrode in a plan view of the substrate. When the thickness of the substrate is t (mm) and the length of the first excitation electrode along the vibration direction is a (mm),
The resonator element according to claim 3, wherein a relationship of −1049t + 57 ≦ a / t ≦ −64.4t + 57 is satisfied. When the thickness of the substrate is t (mm) and the length along the direction perpendicular to the vibration direction of the first excitation electrode is b (mm),
5. The resonator element according to claim 3, wherein a relationship of −823 t + 42 ≦ b / t ≦ −120 t + 42 is satisfied. The first region is spaced apart in the vibration direction and intersects the vibration direction with a first outer edge and a second outer edge, and is spaced apart in a direction perpendicular to the vibration direction and intersects with the vibration direction. 4 outer edges, and
The second region is provided along the first outer edge, provided with a first thick part provided with a fixing part fixed to an object, provided along the third outer edge, and the first The vibration element according to claim 1, further comprising a second thick part connected to the one thick part.   The vibrating element according to claim 6, wherein the second outer edge and the fourth outer edge are exposed from the second region, respectively.   The substrate is a crystal axis of quartz, among an X axis as an electrical axis, a Y axis as a mechanical axis, and a Z axis as an optical axis, the X axis as a rotation axis, and the Z axis as the Y axis The axis tilted so that the + Z side rotates in the −Y direction is the Z ′ axis, the axis tilted so that the + Y side rotates in the + Z direction of the Z axis is the Y ′ axis, the X axis and the 8. The vibration element according to claim 1, wherein the vibration element is a quartz plate having a surface including a Z ′ axis as a main surface and a thickness along a direction along the Y ′ axis. The vibration element according to any one of claims 1 to 8,
And a package for housing the vibration element. The vibration element according to any one of claims 1 to 8,
And an oscillation circuit for driving the vibration element.   An electronic device comprising the vibration element according to claim 1.   A moving body comprising the vibration element according to claim 1.

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