阅读说明：本技术 振动元件以及振荡器 (Vibration element and oscillator ) 是由 西泽龙太 松尾敦司 山口启一 柳炳学 于 2020-10-16 设计创作，主要内容包括：本发明提供振动元件以及振荡器,该振动元件以及振荡器的温度检测精度高。振动元件具有：石英基板,其具有第1振动部和第2振动部；一对第1激励电极,它们在第1振动部处形成在石英基板的两个主面上；以及一对第2激励电极,它们在第2振动部处形成为在石英基板的厚度方向上夹着第2振动部,一对第2激励电极中的至少一个第2激励电极形成在相对于两个主面中的至少一个主面倾斜的倾斜面上。(The invention provides a vibrating element and an oscillator, which have high temperature detection accuracy. The vibration element has: a quartz substrate having a 1 st vibrating section and a 2 nd vibrating section; a pair of 1 st excitation electrodes formed on both principal surfaces of the quartz substrate at the 1 st vibrating portion; and a pair of 2 nd excitation electrodes formed at the 2 nd vibrating portion so as to sandwich the 2 nd vibrating portion in a thickness direction of the quartz substrate, at least one 2 nd excitation electrode of the pair of 2 nd excitation electrodes being formed on an inclined surface inclined with respect to at least one of the two main surfaces.)

1. A vibrating element, comprising:

a quartz substrate having a 1 st vibrating section and a 2 nd vibrating section;

a pair of 1 st excitation electrodes formed on both principal surfaces of the quartz substrate at the 1 st vibrating portion; and

a pair of 2 nd excitation electrodes formed at the 2 nd vibrating portion so as to sandwich the 2 nd vibrating portion in a thickness direction of the quartz substrate,

at least one of the pair of 2 nd excitation electrodes, the 2 nd excitation electrode, is formed on an inclined surface inclined with respect to the two main surfaces.

2. The vibratory element of claim 1, wherein,

the two main surfaces and the inclined surface have different cutting angles.

3. The vibration element according to claim 1 or 2,

the 1 st vibration part and the 2 nd vibration part have different frequency-temperature characteristics.

4. The vibration element of claim 3,

the frequency-temperature characteristic of the 2 nd vibrating portion has a larger amount of frequency change than the frequency-temperature characteristic of the 1 st vibrating portion.

5. The vibratory element of claim 1, wherein,

the inclined surface is inclined so that the thickness of the 2 nd vibrating portion becomes thinner as the inclined surface is farther from the 1 st vibrating portion.

6. The vibratory element of claim 1, wherein,

the inclined surface is inclined so that the thickness of the 2 nd vibrating portion becomes thinner as the 1 st vibrating portion approaches.

7. The vibratory element of claim 1, wherein,

the 1 st vibrating portion has a convex portion formed on at least one of the two main surfaces.

8. The vibratory element of claim 1, wherein,

the vibrating element has a fixing portion for fixing the vibrating element to a package, and at least one of a through hole and a narrow portion is provided between the fixing portion and the 1 st vibrating portion and the 2 nd vibrating portion.

9. The vibratory element of claim 1, wherein,

at least one of a through hole and a thin-walled portion is provided between the 1 st vibrating portion and the 2 nd vibrating portion.

10. An oscillator, having:

the vibration element of any one of claims 1 to 9;

a 1 st oscillation circuit electrically connected to the 1 st excitation electrode and outputting a 1 st oscillation signal;

a 2 nd oscillation circuit electrically connected to the 2 nd excitation electrode and outputting a 2 nd oscillation signal; and

and a control signal output circuit that outputs a control signal for controlling an oscillation frequency of the 1 st oscillation signal based on the 2 nd oscillation signal.

Technical Field

The present invention relates to a vibration element and an oscillator.

Background

Since a quartz resonator having excitation electrodes formed on both principal surfaces of a quartz substrate has stable frequency-Temperature characteristics, it is used as a reference frequency source for an output frequency signal in an Oscillator such as a Temperature Compensated Crystal Oscillator (TCXO). The TCXO includes a temperature compensation circuit using a temperature sensor, and can obtain a stable frequency signal over a wide temperature range. However, since the quartz crystal resonator is housed in a package, a difference in heat transfer time occurs between the quartz crystal substrate and the temperature sensor, and the following problems arise: the temperature measured by the temperature sensor and the temperature of the quartz substrate are different from each other, and the temperature compensation accuracy is lowered.

Therefore, for example, patent document 1 discloses the following structure: a1 st vibrating part for outputting an oscillation signal and a 2 nd vibrating part for detecting temperature are provided on a common piezoelectric plate, and 2 vibrators for outputting an oscillation signal and detecting temperature are formed on 1 piezoelectric plate, so that a difference in heat transfer time between the 2 vibrators is eliminated, and the temperature of the vibrator for outputting an oscillation signal is accurately measured.

Patent document 1: japanese patent laid-open publication No. 2013-98841

However, in the oscillator described in patent document 1, since the excitation electrode for oscillation signal output and the excitation electrode for temperature detection are formed on the same principal surface having the same cut angle, the oscillator for oscillation signal output and the oscillator for temperature detection have the same frequency-temperature characteristics. Since the oscillator for the oscillation signal is set at the cut-off angle such that the frequency change is small with respect to the temperature change, the frequency change of the oscillator for temperature detection is also small with respect to the temperature change, and therefore, there is a problem that the resolution of the temperature change with respect to the frequency change is low, and the temperature of the oscillator for oscillation signal output cannot be detected with high accuracy.

Disclosure of Invention

The vibration element is characterized by comprising: a quartz substrate having a 1 st vibrating section and a 2 nd vibrating section; a pair of 1 st excitation electrodes formed on both principal surfaces of the quartz substrate at the 1 st vibrating portion; and a pair of 2 nd excitation electrodes formed at the 2 nd vibrating portion so as to sandwich the 2 nd vibrating portion in a thickness direction of the quartz substrate, at least one of the 2 nd excitation electrodes of the pair of 2 nd excitation electrodes being formed on an inclined surface inclined with respect to the two principal surfaces.

In the above-described vibration element, it is preferable that the cutting angles of the two main surfaces and the inclined surface are different.

In the above-described vibration element, it is preferable that the 1 st vibration part and the 2 nd vibration part have different frequency-temperature characteristics.

In the above-described vibration element, it is preferable that the frequency-temperature characteristic of the 2 nd vibration part has a larger frequency change amount than the frequency-temperature characteristic of the 1 st vibration part.

In the above-described vibration element, it is preferable that the inclined surface is inclined so that a thickness of the 2 nd vibration portion becomes thinner as the inclined surface becomes farther from the 1 st vibration portion.

In the above-described vibration element, it is preferable that the inclined surface is inclined so that a thickness of the 2 nd vibration portion becomes thinner as the inclined surface approaches the 1 st vibration portion.

In the above-described vibration element, it is preferable that the 1 st vibration part has a convex portion formed on at least one of the two main surfaces.

In the above-described vibration element, it is preferable that the vibration element has a fixing portion for fixing the vibration element to a package, and at least one of a through hole and a narrow width portion is provided between the fixing portion and the 1 st vibration portion and the 2 nd vibration portion.

In the above-described vibration element, it is preferable that at least one of a through hole and a thin-walled portion is provided between the 1 st vibration portion and the 2 nd vibration portion.

The oscillator is characterized by comprising: the above-mentioned vibrating element; a 1 st oscillation circuit electrically connected to the 1 st excitation electrode and outputting a 1 st oscillation signal; a 2 nd oscillation circuit electrically connected to the 2 nd excitation electrode and outputting a 2 nd oscillation signal; and a control signal output circuit that outputs a control signal for controlling an oscillation frequency of the 1 st oscillation signal based on the 2 nd oscillation signal.

Drawings

Fig. 1 is a plan view showing a schematic structure of a vibration element according to embodiment 1.

Fig. 2 is a sectional view taken along line a-a of fig. 1.

Fig. 3 is a view illustrating a cutting angle of the quartz substrate.

Fig. 4 is a graph showing frequency-temperature characteristics of the quartz substrate with respect to the cut angle.

Fig. 5 is a graph showing frequency-temperature characteristics of the vibration element.

Fig. 6 is a flowchart showing a main manufacturing process of the vibration element.

Fig. 7 is a sectional view illustrating a manufacturing process of the vibration element.

Fig. 8 is a sectional view illustrating a manufacturing process of the vibration element.

Fig. 9 is a sectional view illustrating a manufacturing process of the vibration element.

Fig. 10 is a sectional view illustrating a manufacturing process of the vibration element.

Fig. 11 is a sectional view illustrating a manufacturing process of the vibration element.

Fig. 12 is a sectional view illustrating a manufacturing process of the vibration element.

Fig. 13 is a plan view showing a schematic configuration of the vibration element according to embodiment 2.

Fig. 14 is a sectional view taken along line B-B of fig. 13.

Fig. 15 is a plan view showing a schematic configuration of the vibration element according to embodiment 3.

Fig. 16 is a sectional view taken along line C-C of fig. 15.

Fig. 17 is a plan view showing a schematic structure of the vibration element according to embodiment 4.

Fig. 18 is a sectional view taken along line D-D of fig. 17.

Fig. 19 is a plan view showing a schematic configuration of the vibration element according to embodiment 5.

Fig. 20 is a sectional view taken along line E-E of fig. 19.

Fig. 21 is a plan view showing a schematic configuration of an oscillator according to embodiment 6.

Fig. 22 is a sectional view taken along line F-F of fig. 21.

Fig. 23 is a block diagram showing a circuit configuration of the oscillator.

Description of the reference symbols

1.1 a, 1b, 1c, 1 d: a vibrating element; 10: a quartz substrate; 11: 1 st vibration part; 12: a 2 nd vibrating part; 11 a: a 1 st main surface; 11 b: a 2 nd main surface; 12 a: an inclined surface; 13: a fixed part; 14: 1 st through hole; 15: a 2 nd through hole; 16a, 16b, 16 c: a narrow-width portion; 21: 1 st excitation electrode; 22: a 2 nd excitation electrode; 23. 24: a lead electrode; 25. 26: a terminal; 100: an oscillator; x1: 1 st vibration element; x2: a 2 nd vibrating element; θ, θ 1, θ 2: the cut-off angle.

Detailed Description

1. Embodiment 1

First, a vibration element 1 according to embodiment 1 will be described with reference to fig. 1 and 2.

Fig. 1 is a plan view showing a schematic structure of a vibration element 1 according to embodiment 1. Fig. 2 is a sectional view taken along line a-a of fig. 1. In the figure, the X, Y, and Z 'axes are crystal axes of quartz perpendicular to each other, and the Y, Z' axes are axes when the Y, Z axes are rotated around the X axis. The direction along the X axis is referred to as "X direction", the direction along the Y 'axis is referred to as "Y' direction", the direction along the Z 'axis is referred to as "Z' direction", and the direction of the arrow is the positive direction. The positive direction in the Y 'direction is referred to as "up" or "upper", and the negative direction in the Y' direction is referred to as "down" or "lower".

The vibration element 1 of the present embodiment includes: a quartz substrate 10; a 1 st excitation electrode 21 formed on the 1 st vibrating portion 11; a 2 nd excitation electrode 22 formed on the 2 nd vibrating portion 12; terminals 25, 26 formed on the fixing portion 13; and lead electrodes 23, 24 electrically connecting the 1 st excitation electrode 21 and the 2 nd excitation electrode 22 to terminals 25, 26, respectively.

In the vibration element 1, the 1 st vibration element X1 is constituted by the 1 st vibration section 11 in which the pair of 1 st excitation electrodes 21 are formed, the 2 nd vibration element X2 is constituted by the 2 nd vibration section 12 in which the pair of 2 nd excitation electrodes 22 are formed, and the 1 st vibration element X1 and the 2 nd vibration element X2 are coupled.

The quartz substrate 10 is a flat plate having an XZ 'plane as a main surface and a thickness direction in a Y' direction, and includes: a 1 st vibrating portion 11 formed with a 1 st excitation electrode 21; a 2 nd vibrating portion 12 formed with a 2 nd excitation electrode 22; and a fixing portion 13 for fixing the quartz substrate 10 inside a package or the like, not shown.

Between the 1 st vibrating portion 11 and the 2 nd vibrating portion 12 and the fixing portion 13, a 1 st through hole 14, a 2 nd through hole 15, and narrow portions 16a, 16b, and 16c are provided, respectively. Therefore, it is possible to reduce the transmission of stress from the fixing portion 13 to the 1 st vibration portion 11 and the 2 nd vibration portion 12, which is caused by the mounting to the package. The narrow portion is a portion whose length in the Z 'direction of the narrow portion is shorter than the length in the Z' direction of the quartz substrate 10.

The 1 st main surface 11a and the 2 nd main surface 11b of the 1 st vibrating portion 11 are parallel to each other, and a pair of 1 st excitation electrodes 21 are formed on each of the 1 st main surface 11a and the 2 nd main surface 11b so as to overlap in a plan view. In the present embodiment, the 1 st main surface 11a and the 2 nd main surface 11b correspond to two main surfaces.

The 2 nd vibrating portion 12 has an inclined surface 12a inclined with respect to the 1 st main surface 11a, and a pair of 2 nd excitation electrodes 22 are formed on each of the inclined surface 12a and the 2 nd main surface 11b so as to overlap in a plan view. The inclined surface 12a of the 2 nd vibrating portion 12 is inclined so that the thickness of the 2 nd vibrating portion 12 becomes thinner as the distance from the 1 st vibrating portion 11 increases.

The 1 st main surface 11a of the 1 st vibrating portion 11 is formed with: the 1 st excitation electrode 21; a terminal 25 for electrical connection to an oscillation circuit not shown; and a lead electrode 23 for electrically connecting the 1 st excitation electrode 21 and the terminal 25.

The 1 st excitation electrode 21, the terminal 25, and the lead electrode 23 for electrically connecting the 1 st excitation electrode 21 and the terminal 25 are formed on the 2 nd main surface 11b of the 1 st vibrating portion 11.

The 2 nd excitation electrode 22, the terminal 26, and the lead electrode 24 electrically connecting the 2 nd excitation electrode 22 and the terminal 26 are formed on the inclined surface 12a of the 2 nd vibration portion 12.

The 2 nd excitation electrode 22, the terminal 26, and the lead electrode 24 for electrically connecting the 2 nd excitation electrode 22 and the terminal 26 are formed on the 2 nd main surface 11b of the 2 nd vibrating portion 12.

The pair of 1 st excitation electrodes 21 of the 1 st vibration element X1 is formed on the 1 st main surface 11a and the 2 nd main surface 11b of the 1 st vibration portion 11, and the 1 st vibration portion 11 can be vibrated by applying a voltage to the terminal 25.

The 2 nd vibrating element X2 is formed such that the pair of 2 nd excitation electrodes 22 sandwich the 2 nd vibrating portion 12 in the thickness direction of the quartz substrate 10, that is, the pair of 2 nd excitation electrodes 22 are formed on the inclined surface 12a and the 2 nd main surface 11b of the 2 nd vibrating portion 12, and the 2 nd vibrating portion 12 can be vibrated by applying a voltage to the terminal 26.

Next, the quartz substrate 10 of the present embodiment will be described in detail with reference to fig. 3, 4, and 5.

Fig. 3 is a diagram illustrating a cutting angle θ of the quartz substrate 10. Fig. 4 is a graph showing the frequency-temperature characteristics of the quartz substrate 10 with respect to the cut angle θ. Fig. 5 is a graph showing the frequency-temperature characteristics of the vibration element 1.

As shown in fig. 3, the quartz substrate 10 has crystal axes X, Y and Z perpendicular to each other, the X axis is referred to as an electrical axis, the Y axis is referred to as a mechanical axis, the Z axis is referred to as an optical axis, and the quartz substrate 10 is a flat plate cut out along a plane obtained by rotating the XZ plane by a predetermined angle θ around the X axis, and is a so-called rotating Y-cut quartz substrate. The angle θ around the X axis is referred to as a cut-off angle θ. As shown in fig. 4, the frequency-temperature characteristic of the rotating Y-cut quartz substrate is determined by the cut angle θ. Fig. 4 shows frequency-temperature characteristics of the rotating Y-cut quartz substrate with respect to the cutting angle θ at intervals of 2'. According to fig. 4, with respect to the change in temperature T, a characteristic in which the frequency change amount Δ f/f is small and a characteristic in which the frequency change amount Δ f/f is large can be selected by the cutoff angle θ.

When the cutting angle θ of the Y-cut quartz substrate is 35.25 ° (35 ° 15'), the substrate is referred to as an AT-cut quartz substrate, and has excellent frequency-temperature characteristics. Here, the AT-cut quartz substrate has crystal axes X, Y ' and Z ' perpendicular to each other, and the thickness direction is the Y ' direction, and a plane including the X axis and the Z ' axis perpendicular to the Y ' axis is a main surface on which thickness shear vibration is excited as main vibration.

In the quartz substrate 10 of the present embodiment, the 1 st main surface 11a of the 1 st vibrating portion 11 is at a cutting angle θ 1, and the inclined surface 12a of the 2 nd vibrating portion 12 is at a cutting angle θ 2. Since the 2 nd main surface 11b is parallel to the 1 st main surface 11a, the cutting angle is θ 1. Therefore, the 1 st oscillating portion 11 can obtain the frequency-temperature characteristic corresponding to the cutting angle θ 1, and the 2 nd oscillating portion 12 can obtain the frequency-temperature characteristic corresponding to the intermediate angle (θ 1+ θ 2)/2 between the cutting angle θ 2 of the inclined surface 12a and the cutting angle θ 1 of the 2 nd main surface 11 b. When cutoff angle θ 1 of 1 st oscillating portion 11 is set to 35.25 ° (35 ° 15'), frequency-temperature characteristic of 2 nd oscillating portion 12 has a larger frequency change amount Δ f/f than that of 1 st oscillating portion 11.

As shown in fig. 5, the temperature T of the 1 st vibration element X1 can be detected with high accuracy by setting the 1 st vibration element X1 including the 1 st vibration part 11 to be for outputting an oscillation signal having a frequency-temperature characteristic with a small frequency change amount Δ f/f with respect to a temperature change, and setting the 2 nd vibration element X2 including the 2 nd vibration part 12 including the inclined surface 12a to be for detecting a temperature having a frequency-temperature characteristic with a large frequency change amount Δ f/f with respect to a temperature change. Further, since the 1 st oscillation element X1 for outputting the oscillation signal and the 2 nd oscillation element X2 for detecting the temperature are formed on the same quartz substrate 10, there is no difference in heat transfer time, and the temperature T of the 1 st oscillation element X1 can be detected more accurately.

In the present embodiment, the inclined surface 12a is provided on one surface of the 2 nd vibrating portion 12, but the present invention is not limited thereto, and the inclined surface may be provided on the other surface, and the inclined surfaces may be provided on both surfaces of the 2 nd vibrating portion 12.

In the vibration element 1 of the present embodiment, since the 2 nd vibration part 12 has the inclined surface 12a inclined with respect to the 1 st main surface 11a, the 2 nd excitation electrode 22 is formed, so that the frequency-temperature characteristics different from those of the 1 st vibration part 11 can be obtained. Therefore, the temperature T of the 1 st oscillating portion 11 for oscillation signal output can be detected with high accuracy by setting the 1 st oscillating portion 11 for oscillation signal output to have a stable frequency-temperature characteristic and setting the 2 nd oscillating portion 12 for temperature detection to have a frequency-temperature characteristic in which the frequency change amount Δ f/f with respect to temperature change is larger than that of the 1 st oscillating portion 11.

Further, since the cutting angle θ between the 1 st main surface 11a and the inclined surface 12a is different, the frequency-temperature characteristic of the 2 nd vibrating portion 12 having the inclined surface 12a having the cutting angle θ different from that of the 1 st main surface 11a can be made different from that of the 1 st vibrating portion 11.

Further, since the 1 st vibration unit 11 and the 2 nd vibration unit 12 have different frequency-temperature characteristics, the accuracy of temperature detection can be improved by using a vibration unit having a frequency-temperature characteristic in which the frequency change amount Δ f/f based on the temperature T is large for temperature detection.

Further, since the inclined surface 12a is inclined so as to reduce the thickness of the 2 nd vibrating portion 12 as it is separated from the 1 st vibrating portion 11, the cutting angle θ of the 2 nd vibrating portion 12 is different from that of the 1 st vibrating portion 11, and the 2 nd vibrating portion 12 can be made to have a different frequency-temperature characteristic from that of the 1 st vibrating portion 11.

Further, since the frequency-temperature characteristic of the 2 nd oscillating portion 12 has a larger frequency change amount Δ f/f than the frequency-temperature characteristic of the 1 st oscillating portion 11, if the 2 nd oscillating portion 12 is used for temperature detection, the resolution of the temperature change with respect to the frequency change becomes high, and the temperature T of the 1 st oscillating portion 11 can be detected with high accuracy.

Next, a method for manufacturing the vibration element 1 according to the present embodiment will be described with reference to fig. 6 to 12.

Fig. 6 is a flowchart showing a main manufacturing process of the vibration element 1. Fig. 7 to 12 are cross-sectional views for explaining the manufacturing process of the vibration element 1.

As shown in fig. 6, the method for manufacturing the vibration element 1 includes a quartz substrate preparation step, a resist coating step, a pattern forming step, a dry etching step, a singulation step, and an electrode forming step.

1.1 Quartz substrate preparation Process

First, in step S1, a large quartz substrate 80 capable of manufacturing a plurality of vibration elements 1 from a large substrate in a batch process is prepared in consideration of mass productivity and manufacturing cost of the vibration elements 1. The quartz stone of the large quartz substrate 80 is cut at a predetermined cutting angle θ 1, for example, 35.25 ° (35 ° 15'), and is subjected to polishing, buffing, or the like to have a desired thickness.

1.2 resist coating procedure

Next, in step S2, as shown in fig. 7, a resist 82 is applied on the large quartz substrate 80.

1.3 Pattern Forming Process

Next, in step S3, as shown in fig. 8, a photomask 84 having a so-called region where a light-shielding film such as chrome is not patterned, which is a region where the inclined surface 12a is formed on the resist 82, is disposed on the resist 82, and light is irradiated using an exposure apparatus or the like. At this time, the resist 82 is exposed and developed under the condition that the amount of light irradiated to the portion of the large quartz substrate 80 with the reduced thickness is larger than the portion without the reduced thickness, whereby the resist 82 having a film thickness distribution in which the thickness gradually decreases from the portion of the resist 82 with the large thickness toward the portion with the small thickness can be formed. This exposure method is called gray-scale exposure, and in other words, exposure is performed by adjusting the intensity of exposure.

1.4 Dry etching Process

Next, in step S4, when the resist 82 is removed by dry etching from above the large quartz substrate 80 using a plasma etching apparatus or the like, the shape having the inclination formed in fig. 9 is transferred onto the large quartz substrate 80 as shown in fig. 10, and the inclined surface 12a is formed on the large quartz substrate 80. The inclined surface 12a may be formed by a method other than the above-described method. For example, a photosensitive resin may be filled in a mold having a recess corresponding to the shape of the inclined surface 12a, transferred onto the large quartz substrate 80, cured, and then the inclined surface 12a may be formed by a dry etching method.

1.5 singulation Process

Next, in step S5, the large quartz substrate 80 having the inclined surface 12a is cut by, for example, a dicing blade or the like, and singulated, as shown in fig. 11.

1.6 electrode formation Process

Next, in step S6, as shown in fig. 12, the 1 st excitation electrode 21, the 2 nd excitation electrode 22, the lead electrodes 23, 24, and the terminals 25, 26 are formed on the singulated quartz substrate 10 by, for example, a sputtering apparatus, a vapor deposition apparatus, or the like. Through the above steps, the vibration element 1 having the inclined surface 12a is obtained.

The electrode may be formed by photolithography before the singulation step.

2. Embodiment 2

Next, a vibration element 1a according to embodiment 2 will be described with reference to fig. 13 and 14.

Fig. 13 is a plan view showing a schematic configuration of the vibration element 1a according to embodiment 2. Fig. 14 is a sectional view taken along line B-B of fig. 13.

The vibration element 1a of the present embodiment is the same as the vibration element 1 of embodiment 1 except that the shape of the inclined surface 17a provided in the 2 nd vibration part 17 is different from that of the vibration element 1 of embodiment 1. Differences from embodiment 1 will be mainly described, and descriptions of the same matters will be omitted.

As shown in fig. 13 and 14, in the vibrating element 1a, the inclined surface 17a of the 2 nd vibrating portion 17 provided on the quartz substrate 10a is inclined so that the thickness of the 2 nd vibrating portion 17 becomes thinner as it approaches the 1 st vibrating portion 11.

With such a configuration, the cutting angle θ of the 2 nd vibrating portion 17 is different from that of the 1 st vibrating portion 11, and the 2 nd vibrating portion 17 can have a different frequency-temperature characteristic from that of the 1 st vibrating portion 11. Therefore, the temperature T of the 1 st oscillating portion 11 for oscillation signal output can be detected with high accuracy by setting the 1 st oscillating portion 11 for oscillation signal output to have a stable frequency-temperature characteristic and setting the 2 nd oscillating portion 17 for temperature detection to have a frequency-temperature characteristic in which the frequency change amount Δ f/f with respect to temperature change is larger than that of the 1 st oscillating portion 11. Further, since a step is formed between the 1 st main surface 11a of the 1 st vibrating portion 11 and the inclined surface 17a of the 2 nd vibrating portion 17, the vibration energy of the 1 st vibrating portion 11 can be confined in the 1 st vibrating portion 11, and the leakage of vibration from the 1 st vibrating portion 11 to the 2 nd vibrating portion 17 can be reduced. Further, since the substantial vibration region of the 2 nd vibration part 17 can be separated from the 1 st vibration part 11 in the Z' direction in fig. 13 which is the direction in which the 1 st vibration part 11 and the 2 nd vibration part 17 are arranged, the vibrations of the 1 st vibration part 11 and the 2 nd vibration part 17 can be stabilized.

3. Embodiment 3

Next, the vibration element 1b according to embodiment 3 will be described with reference to fig. 15 and 16.

Fig. 15 is a plan view showing a schematic configuration of the vibration element 1b according to embodiment 3. Fig. 16 is a sectional view taken along line C-C of fig. 15.

The vibration element 1b of the present embodiment is the same as the vibration element 1 of embodiment 1 except that the shape of the 1 st vibration part 18 is different from the vibration element 1 of embodiment 1. Differences from embodiment 1 will be mainly described, and descriptions of the same matters will be omitted.

As shown in fig. 15 and 16, in the vibrating element 1b, 2 convex portions 18a are formed on the 1 st vibrating portion 18 of the quartz substrate 10b, and the 1 st excitation electrode 21 is disposed on the convex portions 18 a. One of the projections 18a projects upward from the 1 st main surface 11a of the 1 st vibrating portion 18 in cross section, and the other projection 18a projects downward from the 2 nd main surface 11b in cross section. The convex portion 18a may be formed on either one of the 1 st main surface 11a and the 2 nd main surface 11 b.

With such a configuration, the vibration energy of the 1 st vibration part 18 can be confined in the convex part 18 a. Therefore, the vibration leakage from the 1 st vibration part 18 to the fixing part 13 can be reduced, and the vibration of the 1 st vibration part 18 can be stabilized.

4. Embodiment 4

Next, a vibration element 1c according to embodiment 4 will be described with reference to fig. 17 and 18.

Fig. 17 is a plan view showing a schematic configuration of a vibration element 1c according to embodiment 4. Fig. 18 is a sectional view taken along line D-D of fig. 17.

The vibration element 1c of the present embodiment is the same as the vibration element 1 of embodiment 1 except that the shape of the quartz substrate 10c is different from that of the vibration element 1 of embodiment 1. Differences from embodiment 1 will be mainly described, and descriptions of the same matters will be omitted.

As shown in fig. 17 and 18, the vibrating element 1c has a through hole 19 whose longitudinal direction is the X direction between the 1 st vibrating portion 11 and the 2 nd vibrating portion 12 of the quartz substrate 10 c.

With such a configuration, it is possible to reduce leakage of the vibration of each of the 1 st vibration part 11 and the 2 nd vibration part 12 to the 2 nd vibration part 12 and the 1 st vibration part 11. Therefore, the vibrations of the 1 st vibration part 11 and the 2 nd vibration part 12 can be stabilized more.

5. Embodiment 5

Next, a vibration element 1d according to embodiment 5 will be described with reference to fig. 19 and 20.

Fig. 19 is a plan view showing a schematic configuration of a vibration element 1d according to embodiment 5. Fig. 20 is a sectional view taken along line E-E of fig. 19.

The vibration element 1d of the present embodiment is the same as the vibration element 1 of embodiment 1 except that the shape of the quartz substrate 10d is different from that of the vibration element 1 of embodiment 1. Differences from embodiment 1 will be mainly described, and descriptions of the same matters will be omitted.

As shown in fig. 19 and 20, the vibration element 1d has a recess 20 which is formed between the 1 st vibration part 11 and the 2 nd vibration part 12 of the quartz substrate 10d, has a longitudinal direction in the X direction, and is open downward in cross section, and has a thin portion 30.

With such a configuration, it is possible to reduce leakage of the vibration of each of the 1 st vibration part 11 and the 2 nd vibration part 12 to the 2 nd vibration part 12 and the 1 st vibration part 11. Therefore, the vibrations of the 1 st vibration part 11 and the 2 nd vibration part 12 can be stabilized more.

6. Embodiment 6

Next, an oscillator 100 having vibration elements 1, 1a, 1b, 1c, and 1d according to embodiment 6 will be described with reference to fig. 21 and 22. In the following description, the structure to which the vibration element 1 is applied will be described by way of example.

Fig. 21 is a plan view showing a schematic configuration of an oscillator 100 according to embodiment 6. Fig. 22 is a sectional view taken along line F-F of fig. 21.

As shown in fig. 21, the oscillator 100 includes: a vibrator 40 having a vibration element 1 built therein; an IC chip 60 having oscillation circuits 61, 62 for driving the vibration element 1 and a control signal output circuit 63; a package body 50 that houses the vibrator 40 and the IC chip 60; and a lid member 57 made of glass, ceramic, metal, or the like.

As shown in fig. 22, the package body 50 is formed by stacking the mounting terminal 45, the 1 st substrate 51, the 2 nd substrate 52, and the seal ring 53. In addition, the package body 50 has a cavity 58 opened upward. In addition, the inside of the cavity 58 in which the oscillator 40 and the IC chip 60 are housed is hermetically sealed in a reduced pressure atmosphere or an inert gas atmosphere such as nitrogen gas by bonding the lid member 57 with the seal ring 53.

The mounting terminals 45 are provided in plurality on the outer bottom surface of the 1 st substrate 51. The mounting terminal 45 is electrically connected to the connection electrode 43 and the connection terminal 44 provided above the 1 st substrate 51 via a through electrode and an interlayer wiring, not shown.

Vibrator 40 and IC chip 60 are housed in cavity 58 of package body 50. The vibrator 40 is fixed to the connection electrode 43 provided above the 1 st substrate 51 by solder or a conductive adhesive. The IC chip 60 is fixed above the 1 st substrate 51 via a bonding member 55 such as an adhesive. In addition, a plurality of connection terminals 44 are provided in the chamber 58. The connection terminals 44 are electrically connected to the connection terminals 46 provided above the IC chip 60 by bonding wires 56.

The IC chip 60 includes: a 1 st oscillation circuit 61 that oscillates the 1 st oscillation element X1 and outputs a 1 st oscillation signal; a 2 nd oscillation circuit 62 that oscillates the 2 nd oscillation element X2 and outputs a 2 nd oscillation signal; and a control signal output circuit 63 for outputting a control signal for controlling the oscillation frequency of the 1 st oscillation signal based on the 2 nd oscillation signal.

Next, a circuit configuration of the oscillator 100 will be described with reference to fig. 23.

Fig. 23 is a block diagram showing a circuit configuration of the oscillator 100. In the following description, an example of the oscillator 100 will be described with reference to TCXO.

The oscillator 100 is used for outputting a set frequency f to the outside₀Is configured to be independent of oscillationThe set frequency f is outputted in a manner that the external temperature of the device 100 is changed₀Or the set frequency f can be outputted with suppressing the influence of the external temperature change₀. The set frequency f₀Is at a reference temperature T₀(e.g., 25 ℃ C.) under a reference voltage V₁₀The output frequency obtained when applied to the 1 st oscillation circuit 61.

The 1 st oscillation circuit 61 is electrically connected to the pair of 1 st excitation electrodes 21 of the 1 st vibration element X1 via the terminal 25, and the 2 nd oscillation circuit 62 for detecting temperature is electrically connected to the pair of 2 nd excitation electrodes 22 of the 2 nd vibration element X2 via the terminal 26 in the same manner. A control signal output circuit 63 is provided between the 1 st oscillation circuit 61 and the 2 nd oscillation circuit 62, and the control signal output circuit 63 estimates the temperature of the 1 st oscillation element X1 from the oscillation frequency f as the 2 nd oscillation signal for temperature compensation output from the 2 nd oscillation circuit 62, and calculates the set frequency f that the 1 st oscillation circuit 61 can obtain as the 1 st oscillation signal at the temperature₀Control voltage V of_C(V_CV- Δ V). The reference voltage V is input from the input terminal 64 to the 2 nd oscillation circuit 62₁₀A set frequency f is outputted from an output terminal 65₀. In addition, the control voltage V is stabilized by the varactor 66_CAnd a reference voltage V stabilized by a varactor 66₁₀To the 1 st oscillation circuit 61 and the 2 nd oscillation circuit 62, respectively.

Specifically, the control signal output circuit 63 includes: a frequency detection unit 67 configured by, for example, a frequency counter for measuring an oscillation frequency f from a frequency signal input from the 2 nd oscillation circuit 62; a temperature estimating unit 68 that estimates a temperature T from the oscillation frequency f measured by the frequency detecting unit 67, and a compensation voltage calculating unit 69 that calculates a compensation voltage Δ V from the temperature T estimated by the temperature estimating unit 68; and an addition unit 70 for adding the slave reference voltage V₀A control voltage V obtained by subtracting the compensation voltage DeltaV calculated by the compensation voltage calculation unit 69_CAnd outputs to the 1 st oscillation circuit 61. The temperature estimating unit 68 stores the frequency-temperature characteristics of the 2 nd oscillation circuit 62 shown by the following expression (1), for example, a 3 rd order functionThe temperature of the 1 st vibrating element X1 is obtained from the temperature characteristics and the oscillation frequency f of the 2 nd oscillating circuit 62.

[ formula 1]

f＝f₁₀{1+α₂(T-T₁₀)³+β₂(T-T₁₀)+γ₂}…(1)

The compensation voltage calculation unit 69 has a generator that is a 3-order function, for example, of the temperature characteristic of the 1 st oscillation circuit 61, and is configured to obtain the compensation voltage Δ V from the following expressions (2) to (4) and the temperature T.

[ formula 2]

ΔV＝V₀(Δf/f₀)…(2)

[ formula 3]

Δf/f₀＝α₁(T-T₀)³+β₁(T-T₁₀)+γ₁…(3)

[ formula 4]

ΔV＝V₀{α₁(T-T₀)³+β₁(T-T₀)+γ₁}…(4)

α₁、β₁、γ₁And alpha₂、β₂、γ₂The constants are specific to the 1 st oscillation circuit 61 and the 2 nd oscillation circuit 62, and are obtained by measuring the output frequency while variously changing the temperature and the reference voltage. Further, Δ f ═ f-f₀And f is and₁₀is at a reference temperature T₁₀Lower applied reference voltage V₁₀The output frequency obtained in the 2 nd oscillation circuit 62.

In the oscillator 100, when the reference voltage V is inputted to the input terminal 64₁₀In this case, the 2 nd oscillation circuit 62 oscillates at the thickness-shear vibration of the fundamental wave at the oscillation frequency f obtained by the above equation (1) in accordance with the temperature T of the 2 nd oscillation element X2. The oscillation frequency f is input to the temperature estimating unit 68 via the frequency detecting unit 67, and the temperature T of the 1 st vibrating element X1 is estimated in the temperature estimating unit 68. Then, the compensation voltage calculating unit 69 calculates the compensation voltage Δ V based on the temperature T obtained by the temperature estimating unit 68, and the control voltage V is added via the adding unit 70_CTo the 1 st oscillation circuit 61. In the 1 st oscillation circuit 61, the temperature T and the control voltage V at the 1 st oscillation element X1_CCorresponding oscillation frequency f, i.e. set frequency f₀Next, vibration is performed by thickness shear vibration. That is, it is assumed that the 1 st oscillation circuit 61 is to sum the reference temperature T and the 3 rd order function of the frequency-temperature characteristic of the 1 st oscillation circuit 61 at the temperature T₀Difference (T-T)₀) Correspondingly, the oscillation frequency f is set from the set frequency f₀And (4) offsetting. However, since the set frequency f will be obtained₀Control voltage V of_CApplied to the 1 st oscillating circuit 61, i.e. a reference voltage V₀A control voltage V that is low or high by an amount corresponding to the difference_CSo that the set frequency f can be obtained with the difference being cancelled₀。

The oscillator 100 of the present embodiment outputs a set frequency f as a 1 st oscillation signal to the 1 st oscillation signal based on the oscillation frequency f as a 2 nd oscillation signal oscillated from the 2 nd oscillation element X2₀Since the 2 nd vibrating element X2 has a frequency-temperature characteristic in which the frequency change amount Δ f/f based on the temperature T is larger than that of the 1 st vibrating element X1 as a control signal for controlling, the set frequency f can be set with high accuracy₀Temperature compensation is performed, and the oscillator 100 with high accuracy can be obtained.

Hereinafter, the contents derived from the embodiments are described.

The vibration element is characterized by comprising: a quartz substrate having a 1 st vibrating section and a 2 nd vibrating section; a pair of 1 st excitation electrodes formed on both principal surfaces of the quartz substrate at the 1 st vibrating portion; and a pair of 2 nd excitation electrodes formed at the 2 nd vibrating portion so as to sandwich the 2 nd vibrating portion in a thickness direction of the quartz substrate, at least one of the 2 nd excitation electrodes of the pair of 2 nd excitation electrodes being formed on an inclined surface inclined with respect to the two principal surfaces.

According to this configuration, since the 2 nd vibrating portion has the inclined surface inclined with respect to the main surface, the 2 nd excitation electrode is formed, so that the frequency-temperature characteristic different from that of the 1 st vibrating portion can be obtained. Therefore, by setting one of the 1 st and 2 nd vibrating portions to have stable frequency-temperature characteristics for oscillation signal output and setting the other vibrating portion to have frequency-temperature characteristics having a larger frequency change amount with respect to temperature change than the vibrating portion for oscillation signal output, it is possible to detect the temperature of the vibrating portion for oscillation signal output with high accuracy.

In the above-described vibration element, it is preferable that the cutting angles of the two main surfaces and the inclined surface are different.

According to this configuration, since the cutting angle between the main surface and the inclined surface is different, the frequency-temperature characteristic of the 2 nd vibrating portion having the inclined surface having the cutting angle different from the main surface can be made different from the frequency-temperature characteristic of the 1 st vibrating portion.

In the above-described vibration element, it is preferable that the 1 st vibration part and the 2 nd vibration part have different frequency-temperature characteristics.

According to this configuration, since the 1 st vibration unit and the 2 nd vibration unit have different frequency-temperature characteristics, the accuracy of temperature detection can be improved by using a vibration unit having a frequency-temperature characteristic in which the amount of frequency change with respect to temperature change is large for temperature detection.

In the above-described vibration element, it is preferable that the frequency-temperature characteristic of the 2 nd vibration part has a larger frequency change amount than the frequency-temperature characteristic of the 1 st vibration part.

According to this configuration, since the frequency-temperature characteristic of the 2 nd vibrating portion has a larger amount of frequency change than the frequency-temperature characteristic of the 1 st vibrating portion, if the 2 nd vibrating portion is used for temperature detection, the resolution of the temperature change with respect to the frequency change becomes high, and the temperature of the 1 st vibrating portion can be detected with high accuracy.

In the above-described vibration element, it is preferable that the inclined surface is inclined so that a thickness of the 2 nd vibration portion becomes thinner as the inclined surface becomes farther from the 1 st vibration portion.

According to this configuration, since the inclined surface is inclined so that the thickness of the 2 nd vibrating portion becomes thinner as the inclined surface is farther from the 1 st vibrating portion, the cutting angle of the 2 nd vibrating portion is different from that of the 1 st vibrating portion, and the 2 nd vibrating portion can be made to have a different frequency-temperature characteristic from that of the 1 st vibrating portion.

In the above-described vibration element, it is preferable that the inclined surface is inclined so that a thickness of the 2 nd vibration portion becomes thinner as the inclined surface approaches the 1 st vibration portion.

According to this configuration, since the inclined surface is inclined so that the thickness of the 2 nd vibrating portion becomes thinner as it approaches the 1 st vibrating portion, the cutting angle of the 2 nd vibrating portion is different from that of the 1 st vibrating portion, and the 2 nd vibrating portion can be made to have a different frequency-temperature characteristic from that of the 1 st vibrating portion. Further, since the substantial vibration region of the 2 nd vibration part can be separated from the 1 st vibration part in the direction in which the 1 st vibration part and the 2 nd vibration part are arranged, the vibrations of the 1 st vibration part and the 2 nd vibration part can be stabilized.

In the above-described vibration element, it is preferable that the 1 st vibration part has a convex portion formed on at least one of the two main surfaces.

According to this configuration, the convex portion is formed on the main surface of the 1 st vibrating portion, whereby the vibrational energy of the 1 st vibrating portion can be confined in the convex portion. Therefore, the leakage of vibration from the 1 st vibrating portion to the fixed portion can be reduced, and the vibration of the 1 st vibrating portion can be stabilized.

In the above-described vibration element, it is preferable that the vibration element has a fixing portion for fixing the vibration element to a package, and at least one of a through hole and a narrow width portion is provided between the fixing portion and the 1 st vibration portion and the 2 nd vibration portion.

According to this configuration, since the through-hole and the narrow portion are provided between the 1 st vibrating portion and the 2 nd vibrating portion and the fixing portion, it is possible to reduce vibration leakage from the 1 st vibrating portion and the 2 nd vibrating portion to the fixing portion, and it is possible to reduce transmission of stress associated with mounting to the package from the fixing portion to the 1 st vibrating portion and the 2 nd vibrating portion.

In the above-described vibration element, it is preferable that at least one of a through hole and a thin-walled portion is provided between the 1 st vibration portion and the 2 nd vibration portion.

According to this configuration, since the through hole and the thin portion are provided between the 1 st vibrating portion and the 2 nd vibrating portion, it is possible to reduce the leakage of the vibration of each of the 1 st vibrating portion and the 2 nd vibrating portion to the 2 nd vibrating portion and the 1 st vibrating portion.

The oscillator is characterized by comprising: the above-mentioned vibrating element; a 1 st oscillation circuit electrically connected to the 1 st excitation electrode and outputting a 1 st oscillation signal; a 2 nd oscillation circuit electrically connected to the 2 nd excitation electrode and outputting a 2 nd oscillation signal; and a control signal output circuit that outputs a control signal for controlling an oscillation frequency of the 1 st oscillation signal based on the 2 nd oscillation signal.

According to this configuration, since the control signal for controlling the oscillation frequency of the 1 st oscillation signal is output based on the 2 nd oscillation signal oscillated by the 2 nd oscillation unit having the frequency-temperature characteristic in which the frequency change amount with respect to the temperature change is larger than that of the 1 st oscillation unit, the 1 st oscillation signal can be temperature-compensated with high accuracy, and the high-accuracy oscillator can be obtained.