JP2010219992A - Vibrating reed and vibrator - Google Patents

Abstract

The present invention provides a resonator element and a vibrator capable of stably obtaining good frequency temperature characteristics by suppressing diffusion of an underlayer.
A temperature characteristic correction unit having at least one of an inflection point and an extreme value on a temperature characteristic curve of at least one of a Young's modulus and a thermal expansion coefficient is provided on the surface of a vibrating body having frequency temperature dependency. On the opposite side of the temperature characteristic correction unit 28 from the vibrating body 11, an electrode unit 24 having a property that the base layer 32 constituting the temperature characteristic correction unit 28 diffuses is laminated, and the temperature characteristic correction unit 28, the electrode unit 24, Is provided with a diffusion preventing layer 26 for preventing the diffusion of the underlayer 32, and a temperature characteristic correcting unit 28.
At least one of the temperature at which at least one of the Young's modulus and the coefficient of thermal expansion at the point of inflection becomes an inflection point and the temperature at which the extreme value occurs are within the operating temperature range of the vibrator.
[Selection] Figure 1

Description

The present invention relates to a resonator element and a vibrator on which the resonator element is mounted, and more particularly to a resonator element and a vibrator having good frequency temperature characteristics.

In a vibrating body having frequency temperature dependency, it has long been a problem to improve frequency temperature characteristics. In particular, with respect to a bending vibration piece using a quartz crystal whose frequency temperature characteristic curve is known to change in a quadratic function, various techniques for improving the frequency temperature characteristic have been disclosed.

For example, the technique disclosed in Patent Document 1 is a technique related to a tuning fork-type vibrating piece. The bending direction of the vibrating arm is set to two directions of the XY ′ plane and the Y′Z ′ plane. By generating vibrations and combining them, the frequency temperature characteristics of either one of the vibrations are improved.

In addition, the technique disclosed in Patent Document 2 is also related to a tuning fork type resonator element,
By increasing the film thickness of Cr, which has been conventionally formed as a contact metal under the Au or Ag layer, within a predetermined range, the stress generated in the Cr forming part affects the vibration characteristics and the frequency temperature characteristics are improved. Is.

JP 54-40589 A JP 2005-136499 A

The citation source of FIG. 3 is as follows.
R. Street, “Elasticity and Anelasticity of Chromium”, Physical Review Letters, Vol. 10, No. 6, pp. 210-211, 1963. DFMcMorrow, J. Jensen, HMRonnow, “Magnetism in Metals”, Mat.Fys.Medd.Dan.Vid.Selsk.45 (1997).

According to the above technique, the improvement of the frequency temperature characteristic can certainly be seen. However, the technique disclosed in Patent Document 1 combines two vibrations, which causes a problem that it is difficult to control each vibration.

In addition, the technique disclosed in Patent Document 2 is unclear about the cause of improving the frequency temperature characteristics, and Cr formed in the lower layer (underlayer) with respect to Au or Ag formed as the electrode layer. This causes a problem that the characteristics of the metal film change and the frequency temperature characteristic changes over time or becomes unstable.

Therefore, in the present invention, while investigating the factor that the frequency temperature characteristic is improved by the change in the thickness of the metal film, the resonator element that can stably obtain a favorable frequency temperature characteristic by suppressing the diffusion of the underlayer, An object is to provide a vibrator.

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 forms or application examples.

Application Example 1 A first metal layer having at least one of an inflection point and an extreme value on a temperature characteristic curve of at least one of Young's modulus and thermal expansion coefficient is provided on the surface of a vibrating body having frequency temperature dependency. A diffusion preventing layer for laminating the first metal layer between the first metal layer and the second metal layer by laminating a second metal layer on the opposite side of the first metal layer to the vibrator side. And at least one of the Young's modulus and the thermal expansion coefficient of the first metal layer has at least one of an inflection point and an extreme temperature within the operating temperature range of the vibrator. A vibrating piece.
If the resonator element has such characteristics, it is possible to stably obtain good frequency temperature characteristics.

[Application Example 2] The resonator element according to Application Example 1, wherein the first metal layer is an alloy layer made of multiple elements or an alloy layer generated by diffusion between metal films made of a plurality of single elements, Second
The resonator element, wherein the metal layer is a metal layer made of a single element or an alloy layer made of multiple elements.
According to the resonator element having such characteristics, the temperature within the operating temperature range of the resonator element is taken into consideration based on the temperature that becomes the inflection point or the extreme value of at least one of the Young's modulus and the thermal expansion coefficient. Therefore, it is possible to manufacture a resonator element that can obtain good frequency temperature characteristics according to the purpose and use environment.

[Application Example 3] The vibration piece according to Application Example 1 or Application Example 2, wherein the temperature at the inflection point or the temperature at the extreme value is a Neel temperature.
Since the Neel temperature is a temperature at which the antiferromagnetic material transitions to the paramagnetic state, an extreme value of Young's modulus appears, and the frequency-temperature characteristics can be reliably improved.

Application Example 4 The resonator element according to any one of Application Examples 1 to 3, wherein the first resonator element is the first resonator element.
The resonator element according to claim 1, wherein the metal layer is made of a metal layer composed of Cr as a base layer and an upper layer made of Au or a metal layer made of a Cr-Au alloy, and the second metal layer is made of Au.
In such a configuration, diffusion occurs between Cr and Au constituting the first metal layer in the manufacturing stage, and an alloy as a temperature characteristic correction unit is generated in the first metal layer, and the frequency temperature characteristic is improved. Figured. Since a diffusion preventing layer is provided between the first metal layer and the second metal layer, there is no possibility that Cr will cause diffusion to Au constituting the second metal layer, and an alloy is formed in the first metal layer. There is no possibility that the frequency-temperature characteristic will change with time after.

[Application Example 5] The resonator element according to Application Example 4, wherein the content of Au with respect to Cr in the metal layer formed of the Cr-Au alloy is 0.5% atm or less in atomic percentage. A vibrating piece.
If the Cr film and the Au film are formed at such a ratio, Cr can diffuse into Au in the manufacturing stage. As a result, even if heat or the like is applied after the resonator element is formed, there is no possibility of fluctuations in the frequency temperature characteristics accompanying the progress of Cr diffusion with respect to Au.

[Application Example 6] The vibration piece according to any one of Application Examples 1 to 5, wherein the diffusion prevention layer is one of Ag and Ni.
Ag and Ni do not cause diffusion to Au or Cr and have high conductivity, so that a high Q value when viewed as a vibrator can be maintained.

Application Example 7 A vibrator in which the resonator element according to any one of Application Examples 1 to 6 is mounted inside a package.
According to the vibrator having such a feature, it is possible to obtain a highly reliable vibrator capable of obtaining a favorable frequency temperature characteristic in a wide temperature range.

It is a figure which shows the structure of the vibration piece which concerns on 1st Embodiment. It is a graph which shows the change of the frequency temperature characteristic with respect to the film thickness change of Cr as a temperature characteristic correction | amendment part. It is a graph which shows the relationship between the change of the Young's modulus of Cr, and temperature. It is a graph which shows the relationship between the change of the Neel temperature of Cr, and the metal content rate in alloying. It is a figure which shows the structure of the vibration arm as a characteristic part of the vibration piece which concerns on 2nd Embodiment. It is a figure which shows the structure of the vibration arm as a characteristic part of the vibration piece which concerns on 3rd Embodiment. It is a figure which shows the structure of the vibration arm as a characteristic part of the vibration piece which concerns on 4th Embodiment. It is a figure which shows the example of the vibration piece which makes thickness shear vibration the main vibration. It is a figure which shows the example of the vibration piece which makes a surface acoustic wave the main vibration. It is a figure which shows the cross-sectional structure of the vibrator | oscillator which concerns on invention.

Hereinafter, embodiments of the resonator element and the vibrator according to the present invention will be described in detail with reference to the drawings.
First, a first embodiment according to the resonator element of the invention will be described with reference to FIG. In FIG. 1, FIG. 1A is a plan view of the resonator element, and FIG. 1B is a diagram illustrating a cross section taken along the line AA in FIG.

The resonator element 10 according to the present embodiment will be described by taking as an example a case where crystal is used as a material of an element element that constitutes a vibration body having frequency temperature dependency. Further, the vibration mode will be described by taking a tuning fork type configuration in which bending vibration is the main vibration as an example.

A resonator element 10 according to this embodiment includes a vibrating body 11 and a metal film 1 formed on the vibrating body 11.
6 and. The vibrating body 11 is made of a crystal having a piezoelectric effect, and includes a base portion 12 and the base portion 1.
2 forms a so-called tuning-fork type body having a pair of vibrating arms 14a, 14b extending from 2.
The metal film 16 includes a temperature characteristic correction unit 28 serving as a first metal layer and an electrode unit 24 serving as a second metal layer, and a diffusion prevention layer is provided between the first metal layer and the second metal layer. 26 is provided. In other words, the temperature characteristic correction unit 28 is formed on the surface of the vibration body 11, and the electrode unit 24 is provided on the opposite side of the temperature characteristic correction unit 28 from the vibration body 11. It can be said that the diffusion preventing layer 26 is formed therebetween. The electrode unit 24 is an excitation electrode for exciting vibration, 18a and 18b, and an input / output electrode 2 for inputting and outputting drive signals and detection signals.
2a, 22b, and extraction electrodes 20a, 20b connecting the excitation electrodes 18a, 18b and the input / output electrodes 22a, 22b.

In the present embodiment, the temperature characteristic correction unit 28 as the first metal layer is configured by the base layer 32 (for example, chromium (Cr)) and the upper layer 30 (for example, gold (Au)), the electrode unit 24 is configured by Au, The diffusion prevention layer 26 is made of silver (Ag) or nickel (Ni). Of the metals constituting the temperature characteristic correction unit 28, Cr as the base layer 32 has good adhesion to the quartz used as the vibrator 11 and is excellent as a contact metal, and Au as the upper layer 30 will be described in detail later. For some reason, the Neel temperature, the spin flip temperature, and the like are controlled by intentionally diffusing Cr. In addition, Au has a very low electric resistance, is stable, is not easily affected by oxidation, etc., and has little property change due to aging, so it has been adopted as a constituent member of the electrode portion 24. Further, the use of Ag or Ni as the diffusion preventing layer 26 prevents the diffusion of Cr into the Au (diffusion from the first metal layer to the second metal layer) even when a high temperature is applied. This is because it is possible to prevent the change of the frequency temperature characteristic with time.

Here, the relationship between Cr and Au constituting the temperature characteristic correction unit 28 is as follows.
The ratio of Au as the upper layer 30 may be determined based on the above. Specifically, it is preferable that the content of Au is 0.5% atm or less of Cr in atomic percentage (atomic percent:% atm). By depositing Cr and Au at such a ratio, Cr can be completely diffused with respect to Au in the manufacturing stage, and there is no possibility of diffusion of undiffused Au after the metal film 16 is formed. Can do it.

It can be read from FIG. 2 obtained by experiment that Cr affects the frequency temperature characteristics. The experiment was performed by forming a Cr film on the surface of the vibrating body and an Au film on the upper layer of the Cr film. As shown in FIG. 2, the film thickness of Au was constant (500 mm) and the film thickness of Cr was 1500 mm. (
FIG. 2 (A)), 2000 mm (FIG. 2B), and 2500 mm (FIG. 2C) are recorded to show how the frequency temperature characteristics of the vibrator change. .
The frequency temperature characteristic is changed by increasing the Cr film thickness to the left of the apex temperature (the temperature at which the tangential slope becomes 0), that is, on the temperature side lower than the apex temperature. It can be seen that there is less.

Here, the resonance frequency of the vibrator can be calculated from factors such as the length, width, and thickness of the vibrating portion of the vibrating body 11, the density of the substance constituting the vibrating body 11, boundary conditions, and an elastic constant. . An example of an element that varies due to a change in film thickness or characteristics of the metal film formed on the vibration part is an elastic constant. Among the elements constituting the elastic constant, Young's modulus and thermal expansion coefficient exist as elements that vary with temperature changes. For this reason, it is considered that the temperature dependence of the resonance frequency of the vibrator is also brought about by changes in Young's modulus and thermal expansion coefficient.

Hereinafter, the improvement of the frequency temperature characteristic on the low temperature side accompanying the change in the Cr film thickness will be considered.
FIG. 3 is a graph showing changes in Young's modulus of solid Cr. As can be seen from FIG. 3, it can be seen that the Young's modulus of Cr shows a rapid change at 120 K (spin flip temperature: inflection point) and 310 K (Neil temperature: extreme value).

When the operating temperature range of the vibrator is −55 ° C. to + 125 ° C., preferably −40 ° C. to + 85 ° C., 120K is −153 ° C. and 310K is + 37 ° C. It can be said that it exists within the operating temperature range of the child. Here, the Neel temperature refers to the temperature at which the antiferromagnetic material transitions to the paramagnetic state. Note that antiferromagnetism is a property of magnetism in which adjacent spins are aligned in opposite directions and have no magnetic moment as a whole. Paramagnetism is magnetism that does not have magnetization when there is no external magnetic field and magnetizes weakly in that direction when a magnetic field is applied. That is, it can be said that the rapid change in Young's modulus occurs with the state transition of the magnetic material.

Antiferromagnets are known to cause large volume changes due to the disappearance of magnetic moment by undergoing transition from paramagnetic material at the Neel temperature. With temperature, it can be said that the coefficient of thermal expansion also changes.

It is known that the Neel temperature changes with changes in compressive stress and extensional stress due to differences in film thickness. Specifically, the Neel temperature of Cr thinned compared with solid Cr shifts to the low temperature side or the high temperature side depending on the thermal expansion coefficient of the vibrating body 11 and the Cr film thickness. In consideration of FIG. 2, inflection points that contribute to the improvement of the frequency fluctuation amount (reduction of the frequency fluctuation amount) cannot be seen in FIG. 2A, and in FIG. 2B and FIG. An inflection point occurs on the lower temperature side than the vertex temperature. Each time the film thickness is increased as shown in FIGS. 2B and 2C, the inflection point approaches the apex temperature (shifts to the high temperature side), and the temperature range in which the amount of frequency fluctuation is improved (as the temperature decreases). The temperature range in which the slope of the tangential line becomes smaller also approaches the vertex temperature. This is because the Neel temperature is shifted to the high temperature side by increasing the film thickness of the thinned Cr. From FIG. 2, it is clear that the frequency fluctuation amount is reduced by setting the Cr film thickness to 2000 mm or more and 2500 mm or less, but even when the Cr film thickness is 2500 mm or more, the Neel temperature of the Cr film oscillates. If it is within the operating temperature range of the child, the frequency variation can be reduced.

And, it is considered that the following phenomenon is also caused by the decrease in the Neel temperature accompanying the reduction in the thickness of Cr. Here, an alloy layer in which Au diffuses into the Cr layer exists between Cr and Au. Here, it can be read that an increase in the content of Au leads to a decrease in the Neel temperature of Cr when the change in the Neel temperature accompanying the alloying of Cr shown in FIG. 4 is taken into consideration.

That is, when the film thickness of Cr is thin, the proportion of Au diffused, that is, A in the alloy layer
Since the content of u is increased, it is considered that the Neel temperature is lower than when Cr is simply thinned. When the Cr film thickness is increased, the Au content is naturally reduced and an unalloyed layer is also formed. Therefore, the effective Neel temperature is increased, and the Cr film thickness is increased to 2
When it is set to 500 Å, it is considered that the Neel temperature has reached around 0 ° C. In addition, from the said experiment, the effect as a temperature characteristic correction | amendment part by making the film thickness of Cr 2000 mm or more,
That is, it can be said that there is an effect of improving the frequency temperature characteristic.

Therefore, in the present embodiment, the film thickness of Au constituting the temperature characteristic correction unit 28 is Cr
What is necessary is just to determine so that it may become content of 0.5% atm or less in atomic percent, when it is 2000 tons. By adopting such a configuration, it is possible to improve the frequency temperature characteristics, and after the metal film 16 is formed, the diffusion of undiffused Au cannot occur and the frequency temperature characteristics may change over time. Disappears. In addition, since the Ag film as the diffusion preventing layer 26 is provided between Au as the second metal layer and the first metal layer, there is no possibility that the diffusion of Cr spreads on the second metal layer on the surface.

Further, according to the resonator element 10 according to the embodiment, as described above, the cause of the improvement of the frequency temperature characteristic has been clarified. Therefore, the vibration characteristic can be analyzed by simulation, and the development cost can be reduced. It becomes.

Next, a second embodiment according to the resonator element of the invention will be described with reference to FIG. Note that most of the configuration of the resonator element according to the present embodiment is the same as that of the resonator element according to the first embodiment described above. Therefore, the portions having the same function are denoted by the same reference numerals in the drawings, and detailed description thereof is omitted. For the entire structure of the resonator element, the diagram shown in FIG. .

The resonator element according to the present embodiment is characterized in that the metal film constituting the temperature characteristic correction unit 28 is previously made of an alloy mainly composed of Cr, specifically, a Cr—Au alloy. Cr
As in the first embodiment, the content ratio of Au is less than 0.5% atm in atomic percentage.

According to such a configuration, it is not necessary to determine the film thickness ratio of Cr and Au, and in the manufacturing process, it is possible to reduce the film forming process by one and improve productivity. . In order to obtain the effect of improving the frequency temperature characteristic, the film thickness of the temperature characteristic correction unit 28 according to the present embodiment is set to the temperature characteristic correction unit 28 (underlayer) in the resonator element 10 according to the first embodiment described above. 32 (Cr film) + upper layer 30 (Au film)).

Next, a third embodiment according to the resonator element of the invention will be described with reference to FIG. Note that most of the configuration of the resonator element according to the present embodiment is the same as that of the above-described resonator element according to the first embodiment. Therefore, the portions having the same function are denoted by the same reference numerals in the drawings, and detailed description thereof is omitted. For the entire structure of the resonator element, the diagram shown in FIG. .

As described above, it can be understood that the improvement effect of the frequency temperature characteristic by the temperature characteristic correction unit changes due to the difference in film thickness or alloying. Therefore, in the resonator element 10 according to the present embodiment, the vibrating arm 14a.
, 14b, the metal film 1 having different potentials when applying a voltage.
6, the film thickness of the temperature characteristic correction units 28 a and 28 b, that is, the film thickness of Cr (underlayer 32) and the film thickness of Au (upper layer 30) for diffusing it, or the film thickness of Cr—Au alloy or The content of Au in the Cr—Au alloy was made different.

With such a configuration, two (two types) temperature characteristic correction units 28a and 28b having different Neel temperatures are provided for one vibrating body 11. Thereby, the improvement of the frequency temperature characteristic of the vibrator is achieved by the Neel temperature in each temperature characteristic correction unit 28a, 28b. Therefore, the amount of frequency fluctuation within the operating temperature range is even smaller than when corrected by one type of temperature characteristic correction unit, and the curve indicating the frequency temperature characteristic can be made flatter.

Next, a fourth embodiment according to the resonator element of the invention will be described with reference to FIG. Note that most of the configuration of the resonator element according to the present embodiment is the same as that of the above-described resonator element according to the first embodiment. Therefore, the portions having the same function are denoted by the same reference numerals in the drawings, and detailed description thereof is omitted. For the entire structure of the resonator element, the diagram shown in FIG. .

The resonator element 10 according to the present embodiment is characterized in that the temperature characteristic correcting portions 28a and 28b of the electrode portions having different potentials in the bent portion are configured using different types of metals.

Here, the two types of temperature characteristic correction units 28a and 28b are assumed to have an extreme value of Young's modulus located on the higher temperature side than the apex temperature of the frequency temperature characteristic of the vibrator and located on the lower temperature side. desirable. In the Cr used as the temperature characteristic correction unit in the first embodiment or the like, the Neel temperature, which is an extreme value of Young's modulus, is located on the lower temperature side than the apex temperature of the frequency temperature characteristic. For this reason, the frequency-temperature characteristics are exclusively improved on the lower temperature side than the peak temperature.
For this reason, by adopting a member whose extreme value of Young's modulus is higher than the apex temperature of the frequency temperature characteristic as one of the temperature characteristic correction members, on the higher temperature side than the apex temperature of the frequency temperature characteristic This is because it is considered that the frequency temperature characteristics can be improved.

Specifically, the temperature characteristic correction unit 28 of the excitation electrode 18a formed on the front and back surfaces of the vibrating arm 14a.
When a is composed of Cr (underlayer 32a) and Au (upper layer 30), the temperature characteristic correction unit 28b of the excitation electrode 18b formed on the side surface of the vibrating arm 14a is CrO ₂ (chromium dioxide: underlayer 32b) and Au. (Upper layer 30).

Here, since CrO ₂ is a ferromagnetic material, the temperature at which the Young's modulus exhibits an extreme value is called the Curie temperature. The Curie temperature is a transition temperature at which a ferromagnetic material changes to a paramagnetic material.
Since the Curie temperature of CrO ₂ is 386 K (113 ° C.), it is located on the higher temperature side than the apex temperature (about 30 ° C.) of the frequency temperature characteristic shown in FIG. 2, and the operating temperature range of the vibrator is −55 ° C.
If it is set to ˜ + 125 ° C., the temperature falls within the range, the temperature is lowered by alloying with Au, and it is considered that the temperature falls within the operating temperature range of −40 ° C. to + 85 ° C. Therefore, when the temperature characteristic correction units 28a and 28b are configured by such a combination, it is possible to promote a decrease in the amount of frequency fluctuation on both the high temperature side and the low temperature side of the peak temperature in the frequency temperature characteristic, and within the operating temperature range. The frequency temperature characteristics can be improved over the entire range.

Of course, the two temperature characteristic correction portions 28a and 28b are made of an alloy of Cr—Au and CrO ₂ —A.
You may comprise with the alloy of u.

Further, in the above-described embodiments, it has been described that the temperature characteristic correcting unit is configured on the premise of diffusion into Au mainly composed of Cr or CrO ₂ . However, the temperature characteristic correction unit may be made of a single substance as long as it is a conductor whose Neel temperature or Curie temperature of the thin film is within the operating temperature range of the vibrator. Even in such a case, since the diffusion prevention layer is arranged between the temperature characteristic correction unit as the first metal layer and the electrode unit as the second metal layer, the frequency associated with the diffusion between the two layers This is because changes in temperature characteristics over time can be prevented, and the effect of the present invention is not changed.

In the above embodiments, the main vibration has been described as bending vibration, and the form of the resonator element has been described as a tuning fork type. However, the form of the resonator element according to the invention is not limited to this.

For example, when the main vibration is a thickness shear vibration, a vibration piece as shown in FIG. 8 may be used. Specifically, it is composed of a flat plate-like vibrating body 41 cut out at a cut angle called AT cut, and a metal film 42. The metal film 42 includes a temperature-specific correction unit 50 that is a first metal layer formed on the surface of the vibrating body 41, an electrode unit 49 as a second metal layer that is provided above the temperature characteristic correction unit 50, and an electrode unit. 49 and a diffusion prevention layer 56 disposed between the temperature characteristic correcting unit 50 and the temperature characteristic correcting unit 50. Here, the temperature characteristic correction unit 50 forms a Cr film as the underlayer 54 on the surface of the vibrating body 41 and an Au film as the upper layer 52 on the main surface of the Cr film on the side opposite to the vibrating body 11. The electrode portion 49 can be divided into the excitation electrode 44, the input / output electrode 48, and the extraction electrode 46, and the excitation electrode 44 is formed at a corresponding position on the main surface on the front and back of the vibrating body 41. Further, the temperature characteristic correction unit 50 may be provided only in the lower layer of the electrode unit 49 that constitutes the excitation electrode 44.

In the vibrating piece 40 having such a configuration, the member constituting the temperature characteristic correction unit 50 may be Cr or an alloy mainly composed of Cr as in the above-described various embodiments. Also,
A member constituting the electrode portion 49 may be Au. In addition, the vibration piece 4 having such a configuration
In 0, the main metal constituting the temperature characteristic correction unit 50 may be a material exhibiting a different Neel temperature or Curie temperature on the front and back surfaces of the vibrating body 41.

If the main vibration is a surface acoustic wave, a vibration piece (surface acoustic wave element piece) as shown in FIG. 9 may be used. In FIG. 9, FIG. 9A is a plan view showing the surface acoustic wave element piece, and FIG. 9B is a view showing a cross section AA in FIG. 9A.

The surface acoustic wave element piece 60 has, for example, an element piece called ST cut as a vibrating body 61, and functions as an IDT 64 as an excitation electrode, an input / output electrode 68, and a reflector 66 on one main surface of the vibrating body 61. Is formed. The metal film is composed of the temperature characteristic correction unit 70 as the first metal layer made of Cr as the underlayer 74 and Au as the upper layer 72, or a Cr—Au alloy mainly composed of Cr, and an electrode as the second metal layer The portion 78 may be made of Al, and the diffusion prevention layer 76 made of Ag may be formed between the first metal layer and the second metal layer.

In addition, with respect to the configuration of the resonator element whose main vibration is the lame mode, which is the contour vibration, if a crystal fragment cut at a cut angle called LQ1T cut or LQ2T cut is used as the vibrator, the thickness slipping as a form of forming the metal film By adopting a form similar to that of the vibration piece whose main vibration is vibration, a part of the vibration piece of the present invention can be obtained.

In addition to the vibrating piece having such a vibration mode as a main vibration, a vibrating piece having a main vibration such as a torsional vibration or a boundary wave (Stonley wave or Merfell-Turnuwa wave) is also used as described above. Can be regarded as a part of the present invention.
Moreover, in the said embodiment, although the crystal was used as a vibrating body, regarding the improvement of a frequency temperature characteristic,
If the same effect as the above embodiment can be obtained, lead zirconate titanate (P
bZrTiO ₃₎ or lithium niobate (LiNbO _3), lithium tantalate (LiTa
A piezoelectric body such as O ₃ ), lithium triborate (LiB ₃ O ₅ ), and potassium nitrate (KNO ₃ ), or a semiconductor, that is, a substance other than the piezoelectric body may be used.

Next, a vibrator according to the present invention will be described with reference to FIG.
The vibrator 100 according to this embodiment includes any one of the above-described vibrating bars 10 (40, 60),
A package 110 that accommodates the resonator element 10 and a lid 120 that seals an opening of the package 110 are main components.

The package 110 is a box body obtained by laminating and firing ceramic green sheets and the like, and an internal mounting electrode 112 for mounting the resonator element 10 is formed inside the cavity formed in a concave shape. External mounting terminals 114 are formed on the bottom surface outside the package 110. The external mounting terminal 114 is connected to the internal mounting electrode 11 through a through hole (not shown).
2 is electrically connected.

In the present embodiment, the lid 120 has a flat plate shape. As the constituent member, a metal or glass is often employed. Whatever member is employed, it is desirable to employ a member whose linear expansion coefficient approximates that of the component of the package 110.

The resonator element 10 is mounted on the package 110 configured as described above. A conductive adhesive 116 is used for mounting the resonator element 10. The conductive adhesive 116 is applied to the internal mounting electrode 112, and the input / output electrodes of the resonator element 10 are bonded to the applied conductive adhesive 116.

When the opening of the package 110 on which the resonator element 10 is mounted is sealed, the lid 120 is bonded via the bonding member 118. The joining member 118 differs depending on the members constituting the lid 120. For example, when the lid 120 is a metal, a seal ring made of a low melting point metal is used for the joining member 118. On the other hand, when the lid is made of glass, low-melting glass is used for the bonding member 118.

The vibrator having such a configuration has improved frequency temperature characteristics and can be a vibrator having high reliability in a wide temperature range.

DESCRIPTION OF SYMBOLS 10 ......... Vibrating piece, 11 ......... Vibrating body, 12 ......... Base, 14a, 14b ......... Vibrating arm, 16 ......... Metal film, 18a, 18b ......... Excitation electrode, 20a, 20b ... ... Extraction electrodes, 22a, 22b ......... Input / output electrodes, 24 ......... Electrode portions, 26 ......... Diffusion prevention layer, 28
......... Temperature characteristics correction unit, 30 ......... Upper layer, 32 ...... Underlayer.

Claims (7)

A first metal layer having at least one of an inflection point and an extreme value on a temperature characteristic curve of at least one of Young's modulus and thermal expansion coefficient is provided on the surface of the vibrator having frequency temperature dependency,
Laminating a second metal layer on the opposite side of the first metal layer to the vibrator side;
Providing a diffusion preventing layer for preventing diffusion of the first metal layer between the first metal layer and the second metal layer;
The vibration characterized in that at least one of the Young's modulus and the thermal expansion coefficient in the first metal layer has at least one of an inflection point and an extreme temperature within an operating temperature range of the vibrator. Fragment. The resonator element according to claim 1,
The first metal layer is an alloy layer made of a multielement or an alloy layer generated by diffusion between metal films made of a plurality of single elements, and the second metal layer is a metal layer made of a single element or an alloy made of a multielement. A vibrating piece characterized by being a layer. The resonator element according to claim 1 or 2,
The resonator element according to claim 1, wherein the temperature at the inflection point or the temperature at the extreme value is a Neel temperature. The vibration piece according to any one of claims 1 to 3,
The resonator element according to claim 1, wherein the first metal layer is made of a metal layer made of Cr or an upper layer made of Au or a metal layer made of a Cr—Au alloy, and the second metal layer is made of Au. The resonator element according to claim 4,
The resonator element according to claim 1, wherein the content of Au in the metal layer composed of the Cr—Au alloy with respect to Cr is 0.5% atm or less in atomic percentage. The vibration piece according to any one of claims 1 to 5,
The resonator element, wherein the diffusion preventing layer is one of Ag and Ni. A vibrator comprising the resonator element according to claim 1 mounted inside a package.

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