JP2014064078A - Vibration piece, vibrator, electronic device, electronic apparatus, and mobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an easy-to-vibrate vibrator, by suppressing increase in additional capacity due to cross wiring in a base.SOLUTION: A tuning-fork vibration piece 1 comprises: lower electrode films 15a, 16a, and 17a provided on vibration arms 11, 12, and 13 extending from the base 14; upper electrode films 15c, 16c, and 17c provided above the lower electrode; and piezoelectric films 15b2, 16b2, and 17b2 provided, as insulation layers, between the lower electrodes and upper electrode. The piezoelectric films 15b2, 16b2, and 17b2 provided above the base 14 has a thickness thicker than that of the piezoelectric films 15b2', 16b2', and 17b2' provided above the vibration arms 11, 12, and 13.

Description

  The present invention relates to a resonator element, and a vibrator, an electronic device, an electronic apparatus, and a moving body using the resonator element.

  With the downsizing of tuning fork vibrators, the following resonator element has been adopted in order to achieve downsizing while maintaining the same characteristics as conventional ones. Specifically, a structure having three vibrating arms extending in the same direction from the base is adopted, and an electrode film and a piezoelectric film are laminated on one surface of each vibrating arm to form a piezoelectric element. Yes. In addition, there has been proposed a resonator element that employs an electrical connection in which two piezoelectric elements located outside and an inner piezoelectric element are in opposite phases (see, for example, Patent Document 1).

JP 2009-5022 A

However, since the above-described resonator element employs an electrical connection in which the two piezoelectric elements located outside and the inner piezoelectric element are in opposite phases, electrodes having different phases in the base portion A so-called cross wiring overlapping with a film (insulating layer) is required. By forming such a cross wiring, an additional capacitance C ₀ ′ is generated in a wiring other than the vibrating arm (driving unit). The effective resistance Re (a numerical value indicating the difficulty of vibration of the vibrator) of the vibrator using the resonator element is represented by R _e = R ₁ (1 + C ₀ / C _L ) ^2. C ₀ 'is the effective resistance R _e of the vibrator is increased by being added, the vibrator has occurred a possibility that it becomes difficult to vibrate.

  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 resonator element according to this application example includes a base, a vibrating arm extending from the base, a lower electrode provided on the base and the vibrating arm, and above the lower electrode. An upper electrode provided; and an insulating layer provided between the lower electrode and the upper electrode; and the thickness of the insulating layer provided above the base is determined by the vibrating arm. It is characterized by being thicker than the thickness of the insulating layer provided above.

According to this application example, the thickness of the insulating layer provided above the base is formed larger than the thickness of the insulating layer provided above the vibrating arm. Since the additional capacitance C ₀ ′ is expressed by the following formula (1), the configuration of this application example is such that the thickness of the insulating layer at the base where the cross wiring is generated is larger than the thickness of the insulating layer provided above the vibrating arm. Then, even if cross wiring occurs in the base, it is possible to prevent the additional capacitance C ₀ ′ from increasing in the base region. Therefore, since the effective resistance R _e of the vibrator does not increase, it is possible to provide a vibration easily vibrator.
C ₀ '= ε · S / d (1)
(Ε: dielectric constant (F / m) [ε = ε ₀ × ε _r ... Ε ₀ : vacuum dielectric constant (F / m), ε _r : relative dielectric constant (F / m)], S: parallel Plate area (m ² ) d: Distance between parallel plates (m))

  Application Example 2 In the resonator element according to the application example described above, a dielectric constant of the insulating layer provided above the base is smaller than a dielectric constant of the insulating layer provided above the vibrating arm. It is characterized by that.

As represented by the above formula (1), the smaller the dielectric constant (ε), the smaller the additional capacitance C ₀ ′. According to this application example, since the dielectric constant of the insulating layer provided above the base is smaller than the dielectric constant of the insulating layer provided above the vibrating arm, even if cross wiring occurs at the base, An increase in the additional capacity C ₀ ′ in the base region can be prevented. Therefore, since no increase in effective resistance R _e of the oscillator even if the cross line at the base, it is possible to provide a vibration easily vibrator.

  Application Example 3 A resonator element according to this application example includes a base, a vibrating arm extending from the base, a lower electrode provided on the base and the vibrating arm, and above the lower electrode. An upper electrode provided, and an insulating layer provided between the lower electrode and the upper electrode, wherein a dielectric constant of the insulating layer provided above the base is determined by the vibrating arm. The dielectric constant of the insulating layer provided above is smaller than the dielectric constant.

According to this application example, since the dielectric constant of the insulating layer provided above the base is smaller than the dielectric constant of the insulating layer provided above the vibrating arm, even if cross wiring occurs at the base, An increase in the additional capacity C ₀ ′ in the base region can be prevented. Therefore, since no increase in effective resistance R _e of the oscillator even if the cross line at the base, it is possible to provide a vibration easily vibrator.

  Application Example 4 In the resonator element according to the application example described above, the vibrating arm includes a first vibrating arm and a second vibrating arm, and extends from the first vibrating arm to the base. The lower electrode and the upper electrode extending from above the second vibrating arm to above the base overlap each other via the insulating layer above the base. To do.

According to this application example, it is possible to prevent an increase in the additional capacitance C ₀ ′ due to the cross wiring at the base. Therefore, since the effective resistance R _e of the vibrator does not increase, it is possible to provide a vibration easily vibrator.

  Application Example 5 In the resonator element according to the application example described above, the insulating layer includes a piezoelectric film.

According to this application example, by including a piezoelectric film in the insulating layer, it is possible to increase the thickness of the insulating layer and to prevent an increase in the additional capacitance C ₀ ′ due to the cross wiring.

  Application Example 6 In the resonator element according to the application example, the base and the vibrating arm are made of quartz.

  According to this application example, it is possible to suppress a decrease in temperature characteristics (characteristics having temperature dependence such as frequency temperature characteristics) due to miniaturization by using quartz.

  Application Example 7 In the resonator element according to the application example described above, the base portion and the vibrating arm are made of a semiconductor.

  According to this application example, the outer shape processing using photolithography or the like is easy, and the etching rate is constant, so that the formed outer shape becomes uniform and stable characteristics can be obtained.

  Application Example 8 A vibrator according to this application example includes the resonator element according to any one of the application examples described above and a container that stores the resonator element.

  According to this application example, since the above-described vibrating piece is used, it is possible to provide a vibrator that easily vibrates.

  Application Example 9 An electronic device according to this application example includes the resonator element according to any one of the application examples described above and a circuit element that drives the resonator element.

  According to this application example, since the above-described vibration piece is used, the vibration piece easily vibrates, and an electronic device with stable vibration can be provided.

  Application Example 10 An electronic apparatus according to this application example includes the resonator element according to any one of the application examples described above.

  According to this application example, since the above-described vibration piece is used, the vibration piece easily vibrates, and thus an electronic apparatus having stable characteristics can be provided.

  Application Example 11 A moving object according to this application example includes the resonator element according to any one of the application examples described above.

  According to this application example, since the above-described resonator element is used, the resonator element is likely to vibrate, and thus a moving body that can exhibit stable performance can be provided.

The tuning fork type vibration piece of 1st Embodiment is shown, (a) is a top view of a tuning fork type vibration piece, (b) is QQ sectional drawing shown to (a), (c) is RR of (a). Sectional drawing. It is a figure explaining the structure of the insulating layer of the tuning fork type vibration piece of 2nd Embodiment, (a) is sectional drawing of the position equivalent to QQ of Fig.1 (a), (b) is FIG. Sectional drawing of the position equivalent to RR of). The circuit diagram explaining the equivalent circuit of a vibration piece. FIG. 3 is a front sectional view showing a vibrator using the resonator element according to the invention. FIG. 5 is a front sectional view showing an oscillator as an electronic device using the resonator element according to the invention. The perspective view which shows the structure of the mobile type personal computer as an example of an electronic device. The perspective view which shows the structure of the mobile telephone as an example of an electronic device. The perspective view which shows the structure of the digital still camera as an example of an electronic device. The perspective view which shows the structure of the motor vehicle as an example of a mobile body.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1A and 1B show a tuning fork type vibrating piece according to a first embodiment of the vibrating piece of the present invention, wherein FIG. 1A is a plan view of the tuning fork type vibrating piece, and FIG. 1B is a QQ cross section shown in FIG. FIG. 4C is an RR cross-sectional view of FIG. 2A and 2B are views for explaining the configuration of an insulating layer of a tuning-fork type resonator element according to the second embodiment of the resonator element of the invention, wherein FIG. 2A is a QQ cross-sectional view of FIG. ) Is an RR cross-sectional view of FIG. FIG. 3 is a circuit diagram illustrating an equivalent circuit of the resonator element.

(First embodiment)
A tuning-fork type resonator element 1 according to this embodiment shown in FIG. 1 includes vibrating arms 11, 12, 13, a base 14 that connects one end of each of the three vibrating arms 11, 12, 13, and a piezoelectric element 15. , 16 and 17.

  The vibrating arm 11 has a first surface 11a arranged in the first direction (Z direction in the drawing). Similarly, the vibrating arm 12 has a first surface 12a arranged in the first direction, and the vibrating arm 13 has a first surface 13a arranged in the first direction. In the present embodiment, each of the first surfaces 11a, 12a, and 13a is a flat surface, but is not limited thereto, and may be a curved surface, an uneven surface, or the like. These vibrating arms 11, 12, and 13 are arranged along a second direction (X direction in the drawing) that intersects the first direction. The resonating arms 11, 12, and 13 are arranged such that the longitudinal direction thereof is along the third direction (Y direction in the drawing). The cross-sectional shapes of the vibrating arms 11, 12, and 13 are rectangular as shown in FIG. 1B, for example, but are not limited to this shape.

  The base portion 14 is connected to one end (one end portion along the Y direction) of each of the three vibrating arms 11, 12, 13, and couples these vibrating arms 11, 12, 13. And the base 14 has comprised the shape where the width | variety (dimension of a 2nd direction) became wide in the middle of the 3rd direction. In the present embodiment, the vibrating arms 11, 12, 13 and the base portion 14 are integrally formed. Each vibrating arm 11, 12, 13 and the base 14 are formed by, for example, processing a shape of a quartz plate. The quartz plate is preferably a Z-cut plate from the viewpoint of the cut angle, but may be an X-cut plate or an AT-cut plate. When a Z-cut plate is used, processing becomes easy.

  The piezoelectric element 15 is provided on the first surface 11 a of the vibrating arm 11. Similarly, the piezoelectric element 16 is provided on the first surface 12 a of the vibrating arm 12, and the piezoelectric element 17 is provided on the first surface 13 a of the vibrating arm 13.

FIG. 1B is a cross-sectional view illustrating the structure of the piezoelectric elements 15, 16, and 17 provided on the first surfaces 11 a, 12 a, and 13 a of the vibrating arms 11, 12, and 13. Since the piezoelectric elements 15, 16, and 17 have the same structure, the piezoelectric element 15 will be described here. The piezoelectric element 15 is disposed on the lower electrode film 15a disposed on the first surface 11a, the piezoelectric film 15b2 serving as an insulating layer disposed on the lower electrode film 15a, and the piezoelectric film 15b2. And the upper electrode film 15c. This piezoelectric film 15b2 is a film containing, for example, any one of ZnO, AlN, PZT, LiNbO ₃ or KNbO ₃ . The film thickness of the piezoelectric film 15b2 is, for example, about 0.2 μm. The film thickness of the piezoelectric film 15b2 is preferably set to about 0.025 to 0.25 times the thickness of the vibrating arm 11.

  FIG. 1C is a cross-sectional view showing the structure of the piezoelectric elements 15 ′, 16 ′, and 17 ′ provided on the first surface 14 a of the base portion 14. Piezoelectric elements 15 ′, 16 ′, and 17 ′ provided on the base portion 14 have thicknesses t1 of the piezoelectric films 15b2, 16b2, and 17b2 provided on the aforementioned vibrating arms 11, 12, and 13 (FIG. 1 ( Compared to b))), the piezoelectric films 15b2 ′, 16b2 ′, and 17b2 ′ have a larger thickness t2. Since the piezoelectric elements 15 ′, 16 ′, and 17 ′ have the same structure, the details will be described using the piezoelectric element 15 ′. The piezoelectric element 15 ′ provided on the base 14 includes a lower electrode film 15a disposed on the first surface 14a, a piezoelectric film 15b2 ′ as an insulating layer disposed on the lower electrode film 15a, and a piezoelectric element. And an upper electrode film 15c disposed on the body film 15b2 ′. The lower electrode film 15 a provided on the first surface 14 a of the base portion 14 extends from the lower electrode film 15 a provided on the first surface 11 a of the vibrating arm 11. The piezoelectric film 15 b 2 ′ provided on the first surface 14 a of the base portion 14 is connected to the piezoelectric film 15 b 2 provided on the vibrating arm 11. The upper electrode film 15 c provided above the base portion 14 extends from the upper electrode film 15 c on the piezoelectric film 15 b 2 ′ disposed on the upper side of the vibrating arm 11.

  The lower electrode films 15a, 16a, 17a and the upper electrode films 15c, 16c, 17c are conductor films such as a chromium film, a gold film, a titanium film, an aluminum film, a molybdenum film, and an ITO film, respectively. Among these, the lower electrode films 15a and 17a of the piezoelectric elements 15 and 17 provided on the two vibrating arms 11 and 13 arranged on the outside in the X direction, and one piece arranged on the inside in the X direction. The upper electrode film 16c of the piezoelectric element 16 provided on the vibrating arm 12 is electrically connected to each other. Further, the upper electrode films 15c and 17c of the piezoelectric elements 15 and 17 provided on the two vibrating arms 11 and 13 arranged on the outer side in the X direction, and one vibrating arm arranged on the inner side in the X direction. 12 are electrically connected to the lower electrode film 16a of the piezoelectric element 16 provided on the substrate 12.

  The connection structure of each electrode film will be further described mainly with reference to FIG. The upper electrode film 15c and the upper electrode film 17c are electrically connected to each other through the electrode pad 24. In the present embodiment, the upper electrode films 15c and 17c and the electrode pad 24 are integrally formed. The lower electrode film 16a is electrically connected to the upper electrode film 17c through a connection portion 18a using, for example, a through-hole wiring. Thus, the upper electrode films 15c and 17c and the lower electrode film 16a are electrically connected to each other. Through this electrode pad 24, electric signals having the same potential can be supplied to the upper electrode films 15c and 17c and the lower electrode film 16a.

  The lower electrode film 15a and the lower electrode film 17a are electrically connected to each other via a connection portion 18b using a through-hole wiring or the like and an electrode pad 26, for example. In the present embodiment, the electrode pad 26 is formed simultaneously with the electrode pad 24 described above. The upper electrode film 16c is electrically connected to the lower electrode film 15a via a connection portion 18c using, for example, a through-hole wiring at a position extending above the base portion 14. Thus, the lower electrode films 15a and 17a and the upper electrode film 16c are electrically connected to each other. Through this electrode pad 26, electric signals having the same potential can be supplied to the lower electrode films 15a and 17a and the upper electrode film 16c.

  By alternately supplying an electric signal having a reverse potential to the electrode pad 24 and the electrode pad 26, the vibrating arms 11 and 13 and the vibrating arm 12 can be alternately vibrated up and down. Specifically, when a voltage is applied between each upper electrode film and lower electrode film, the direction of the electric field applied to each of the outer piezoelectric elements 15 and 17 and the direction of the electric field applied to the inner piezoelectric element 16 And reverse. Therefore, the vibration direction of the vibration arms 11 and 13 and the vibration direction of the vibration arm 12 are opposite to each other, and the vibration arms 11 and 13 and the vibration arm 12 alternately move up and down by applying an electric field. As described above, by using a tripod structure, the Q value can be increased even in a vibration mode using vertical vibration (vibration along the Z direction in the figure).

  As in the above-described configuration, the potential of the electrode of the vibrating arm 12 sandwiched between the two vibrating arms 11 and 13 is reversed, and the electrode pad 24 and the electrode pad 26 provided on the base 14 and the respective electrode films are provided. Connected. Therefore, the lower electrode films 15a, 16a, and 17a and the upper electrode films 15c, 16c, and 17c are opposed to each other through the piezoelectric films 15b2 ′, 16b2 ′, and 17b2 ′ as insulating layers in the base portion 14. The part which becomes cross wiring will arise. This cross wiring portion is indicated by P1, P2, P3, and P4 in FIG.

Here, the influence on the tuning fork type resonator element 1 due to the occurrence of the cross wiring will be described with reference to FIG. FIG. 3 shows an equivalent circuit showing the electrical characteristics of the resonator element (vibration element) when cross wiring is generated (L ₁ : equivalent inductance, C ₁ : equivalent capacitance, R ₁ : equivalent resistance, C ₀ : Capacitance, C ₀ ': Additional capacitance due to cross wiring at the base).

When causing cross line to the base 14 to the above so, the additional capacitance C ₀ 'is added in addition to the electrostatic capacitance C _0. The effective resistance Re (a numerical value indicating the difficulty of vibration of the vibrator) of the resonator element (vibration element, vibrator) is represented by R _e = R ₁ (1 + C ₀ / C _L ) ^2. effective resistance R _e of the vibrator by additional capacitance C ₀ 'is added is increased. As a result, the vibrator is less likely to oscillate, in other words, less likely to vibrate.

However, in the tuning fork type vibrating piece 1 of the present embodiment, the thickness t2 of the piezoelectric films 15b2 ′, 16b2 ′, and 17b2 ′ as the insulating layers provided above the base portion 14 is such that the vibrating arms 11, 12, and 13 Is formed to be larger than the thickness t1 of the piezoelectric films 15b2, 16b2, and 17b2 as insulating layers provided above. Since the additional capacitance C ₀ ′ decreases as the distance d between the parallel plates increases as shown in the following formula (1), in the configuration of the present embodiment, the additional capacitance C ₀ ′ is generated even if cross wiring occurs in the planar region of the base portion 14. An increase in C ₀ ′ can be prevented. Thereby, the tuning fork type vibrating piece 1 having the configuration of the present embodiment can keep the effective resistance _Re small, and thus can be a vibrating piece that easily oscillates.
C ₀ '= ε · S / d (1)
(Ε: dielectric constant (F / m) [ε = ε ₀ × ε _r ... Ε ₀ : vacuum dielectric constant (F / m), ε _r : relative dielectric constant (F / m)], S: parallel Plate area (m ² ) d: Distance between parallel plates (m))

(Second Embodiment)
Next, a tuning fork type vibrating piece according to a second embodiment of the vibrating piece of the present invention will be described with reference to FIG. 2A and 2B are diagrams for explaining the configuration of the insulating layer of the tuning-fork type resonator element according to the second embodiment. FIG. 2A is a cross-sectional view corresponding to the position of QQ in FIG. It is sectional drawing equivalent to the position of RR of Fig.1 (a). The plan view (plan view) of the tuning fork type vibrating piece according to the second embodiment is the same as that of the first embodiment described above. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof may be omitted.

  The piezoelectric elements 15, 16, 17 provided on the first surfaces 11 a, 12 a, 13 a of the vibrating arms 11, 12, 13 of the tuning fork type vibrating piece 1 of the second embodiment shown in FIG. The structure further includes an insulating film. Since the structures of the piezoelectric elements 15, 16, and 17 are the same as described above, the piezoelectric element 17 will be described here.

  The piezoelectric element 17 includes a lower electrode film 17a disposed on the first surface 13a, an insulating layer 17b disposed on the lower electrode film 17a, and an upper electrode film 17c disposed on the insulating layer 17b. Contains.

In the second embodiment, the insulating layer 17b includes an insulating film 17b1 and a piezoelectric film 17b2. The insulating film 17b1 is disposed between the piezoelectric film 17b2 and the lower electrode film 17a. The insulating film 17b1 is, for example, a silicon oxide (SiO ₂ ) film. The insulating film 17b1 functions to prevent a short circuit between the lower electrode film 17a and the upper electrode film 17c. The film thickness of the insulating film 17b1 is desirably 25 nm or more from the viewpoint of short circuit prevention, and is desirably 500 nm or less from the viewpoint of suppressing deterioration in characteristics of the piezoelectric element 15. The piezoelectric film 17b2 is a film containing, for example, any one of ZnO, AlN, PZT, LiNbO _3, or KNbO ₃ . The film thickness of the piezoelectric film 17b2 is, for example, about 0.2 μm. The film thickness of the piezoelectric film 17b2 is preferably set to about 0.025 to 0.25 times the thickness of the vibrating arm 11.

  In addition, the piezoelectric elements 15 ′, 16 ′, and 17 ′ provided on the first surface 14 a of the base portion 14 shown in FIG. As shown in FIG. 2B, the thickness of the insulating film 17b1 ′ in the insulating layer 17b ′ is the same as that of the insulating film 17b1 in the insulating layer 17b provided on the above-described vibrating arms 11, 12, and 13. It is formed larger than the thickness. Therefore, the thickness of the insulating layer 17 b ′ provided on the base portion 14 is also larger than the thickness of the insulating layer 17 b provided on the vibrating arms 11, 12, and 13.

According to the tuning fork type resonator element 1 of the second embodiment, as in the first embodiment, the thickness of the insulating layers 15b ′, 16b ′, and 17b ′ provided above the base portion 14 is such that the vibration is reduced. It is larger than the thickness of the insulating layers 15b, 16b, and 17b provided above the arms 11, 12, and 13. Therefore, similarly to the first embodiment, it is possible to prevent the additional capacitance C ₀ ′ from increasing even if cross wiring occurs in the planar region of the base portion 14. Thereby, the tuning fork type vibrating piece 1 having the configuration of the present embodiment can keep the effective resistance _Re small, and thus can be a vibrating piece that easily oscillates.

  In the present embodiment, the piezoelectric elements 15 ′, 16 ′, and 17 ′ provided on the first surface 14a of the base 14 shown in FIG. 2B are formed on the insulating film 17b1 on the upper surface of the lower electrode film 17a. In the above description, the piezoelectric film 17b2 is provided on the upper surface of the insulating film 17b1 '. However, the piezoelectric film 17b2 is provided on the upper surface of the lower electrode film 17a, and the upper surface of the piezoelectric film 17b2 is insulated. A configuration in which the film 17b1 ′ is provided may also be used.

  In the above-described embodiment, the tuning fork-type vibrating piece 1 having the three vibrating arms 11, 12, and 13 has been described, but the number of vibrating arms may be an odd number of five or more.

The base material of the resonator element is not limited to quartz, but lithium tantalate (LiTaO ₃ ), lithium tetraborate (Li ₂ B ₄ O ₇ ), lithium niobate (LiNbO ₃ ), zirconate titanate It may be a piezoelectric material such as lead (PZT), zinc oxide (ZnO), aluminum nitride (AlN), or a semiconductor material such as silicon.

In addition, in order to suppress the additional capacitance C ₀ ′ due to the cross wiring, a material having a low dielectric constant can be used for the insulating layer based on the above formula (1). The material of the insulating layer used above the base portion 14 that generates the cross wiring may be a material having a smaller dielectric constant than the material of the insulating layer used above the vibrating arms 11, 12, and 13. As a material having a small dielectric constant, for example, SiN, Al anodized film, SiO ₂ (F addition), SiOC, or the like can be used. By using such a material having a low dielectric constant as the insulating layer, it is possible to prevent the additional capacitance C ₀ ′ from becoming large even if cross wiring occurs in the planar region of the base portion 14. Thereby, it becomes possible to keep small the effective resistance R _e, it is possible to provide an oscillation easily vibrating piece. When the material of the insulating layer used above the base portion 14 is a material having a lower dielectric constant than the material of the insulating layer used above the vibrating arms 11, 12, 13, it is used above the vibrating arms 11, 12, 13. The thickness of the insulating layer and the thickness of the insulating layer used above the vibrating arms 11, 12, 13 may be the same or different.

(Vibrator)
Next, a vibrator including the resonator element described in each of the above embodiments will be described using an example in which the tuning fork type resonator element 1 of the first embodiment is used. FIG. 4 is a front sectional view schematically showing a schematic configuration of the vibrator. In addition, the same code | symbol is attached | subjected to a common part with the said 1st Embodiment, detailed description is abbreviate | omitted, and it demonstrates centering on a different part from the said 1st Embodiment.

  As shown in FIG. 4, the vibrator 5 includes the tuning fork type vibrating piece 1 described in the first embodiment and a package 20 that houses the tuning fork type vibrating piece 1.

  The package 20 includes a package base 21 having a substantially rectangular planar shape and a recess, and a lid 22 having a substantially rectangular planar shape covering the recess of the package base 21 and is formed in a substantially rectangular parallelepiped shape. Yes. The package base 21 is made of an aluminum oxide sintered body, crystal, glass, silicon, or the like formed by laminating and firing ceramic green sheets. The lid 22 is made of the same material as the package base 21 or a metal such as Kovar, 42 alloy, or stainless steel.

  The package base 21 is provided with an internal terminal 34 on an inner bottom surface (a bottom surface inside the recess) 23. The internal terminal 34 is formed in a substantially rectangular shape at a position near the electrode pad 26 (24) provided on the base 14 of the tuning fork type vibrating piece 1. The electrode pad 26 (24) is connected to the lower electrode films 15a, 16a, and 17a of the tuning fork-type vibrating piece 1 or the upper electrode films 15c, 16c, and 17c by wiring (not shown).

  A pair of external terminals 27 and 28 used when mounted on an external member such as an electronic device is formed on the outer bottom surface (the surface opposite to the inner bottom surface 23, the outer bottom surface) 36 of the package base 21. . The external terminals 27 and 28 are connected to the internal terminal 34 by internal wiring (not shown). For example, the external terminal 27 is connected to the internal terminal 34, and the external terminal 28 is connected to another internal terminal (not shown). The internal terminals 34 and the external terminals 27 and 28 are made of a metal film obtained by laminating each film such as Ni and Au on a metallized layer such as W (tungsten) by a method such as plating.

  The vibrator 5 includes a package base 21 in which a fixing portion (a portion thicker than the vibrating arms 11, 12, 13) of the base portion 14 of the tuning fork-type vibrating piece 1 is bonded via an adhesive 30 such as epoxy, silicone, or polyimide. It is being fixed to the inner bottom face 23. In the vibrator 5, the electrode pad 26 (24) of the tuning fork type vibrating piece 1 is connected to, for example, an internal terminal 34 by a metal wire 31 such as Au or Al. In the vibrator 5, the tuning fork type resonator element 1 is connected to the internal terminal 34 of the package base 21, the recess of the package base 21 is covered with the lid 22, and the package base 21 and the lid 22 are seam-ringed and have a low melting point. The inside of the package 20 is hermetically sealed by being joined by a joining member 29 such as glass or adhesive. Note that the inside of the package 20 is in a reduced pressure state (high vacuum state) or in a state filled with an inert gas such as nitrogen, helium, or argon.

  The package may include a flat package base and a lid having a recess. The package may have a recess in both the package base and the lid.

  The vibrator 5 is connected to the tuning-fork type vibrating piece 1 by a drive signal (alternating voltage) applied to the piezoelectric element (such as 16) via the external terminals 27 and 28, the metal wire 31, and the electrode pad 26 (24). Each vibrating arm (such as 12) vibrates (resonates) at a predetermined frequency.

  As described above, since the vibrator 5 includes the tuning fork type resonator element 1, it is possible to provide the effect described in the first embodiment, that is, a small vibrator that easily oscillates.

(Electronic device)
Next, an oscillator as an electronic device provided with the tuning fork type resonator element described in each of the above embodiments will be described using an example using the tuning fork type resonator element 1 of the first embodiment. FIG. 5 is a front sectional view schematically showing a schematic configuration of an oscillator as an example of an electronic device. Each wiring is omitted. Also, common parts with the first embodiment will be denoted by the same reference numerals, detailed description thereof will be omitted, and different parts from the first embodiment will be mainly described.

  As shown in FIG. 5, the oscillator 6 includes the tuning fork type vibrating piece 1 described in the first embodiment, an IC chip 40 as an oscillation circuit for oscillating the tuning fork type vibrating piece 1, the tuning fork type vibrating piece 1 and the IC. And a package 20 containing the chip 40.

  An internal connection terminal 32 a is provided on the inner bottom surface 32 of the package base 21. The IC chip 40 incorporating the oscillation circuit is fixed to the inner bottom surface 32 of the package base 21 using an adhesive 32b or the like. In the IC chip 40, a connection pad (not shown) is connected to the internal connection terminal 32a by a metal wire 41 such as Au or Al.

  The internal connection terminal 32a is made of a metal film in which a film such as Ni or Au is laminated on a metallized layer such as W (tungsten) by plating or the like, and the external terminals 27 and 28 of the package 20 via internal wiring (not shown). Are connected to the internal terminal 34 and the like. For connecting the connection pads of the IC chip 40 and the internal connection terminals 32a, a connection method by flip chip mounting by inverting the IC chip 40 is used in addition to a connection method by wire bonding using the metal wire 41. May be.

  An internal terminal 34 is provided on the inner bottom surface (the bottom surface inside the recess) 23 of the package base 21. The internal terminal 34 is formed in a substantially rectangular shape at a position near the electrode pad 26 (24) provided on the base 14 of the tuning fork type vibrating piece 1. The electrode pad 26 (24) is connected to the lower electrode films 15a, 16a, and 17a of the tuning fork-type vibrating piece 1 or the upper electrode films 15c, 16c, and 17c by wiring (not shown).

  The tuning fork type vibrating piece 1 has an inner bottom surface 23 of the package base 21 with an adhesive 30 such as an epoxy-based, silicone-based, or polyimide-based adhesive portion (a portion thicker than the vibrating arms 11, 12, 13) of the base portion 14. It is fixed to. The electrode pad 26 (24) of the tuning fork type resonator element 1 is connected to, for example, the internal terminal 34 by a metal wire 31 such as Au or Al.

  The oscillator 6 is connected to the lower electrode films 15a, 16a, 17a or the upper electrode films 15c, 16c, 17c from the IC chip 40 via the internal connection terminals 32a, the internal terminals 34, the metal wires 31, and the electrode pads 26 (24). The vibrating arms (12 and the like) of the tuning fork-type vibrating piece 1 oscillate (resonate) at a predetermined frequency by the drive signal applied to. The oscillator 6 outputs an oscillation signal generated along with the oscillation to the outside via the IC chip 40, the internal connection terminal 32a, the external terminals 27 and 28, and the like.

  As described above, since the oscillator 6 includes the tuning fork type resonator element 1, it is possible to provide the effect described in the first embodiment, that is, a small and easily oscillating oscillator.

  The oscillator 6 may have a module structure in which the IC chip 40 is not built in the package 20 but is externally attached (for example, a structure in which a crystal resonator and an IC chip are individually mounted on one substrate). .

[Electronics]
Next, regarding an electronic device to which the tuning fork type vibrating piece 1 as a vibrating piece according to an embodiment of the present invention, the vibrator 5 using the tuning fork type vibrating piece 1, or the oscillator 6 using the tuning fork type vibrating piece 1 is applied. This will be described in detail with reference to FIGS. In the description, an example in which a vibrator using the tuning fork type vibrating piece 1 is applied is shown.

  FIG. 6 is a perspective view schematically showing a configuration of a mobile (or notebook) personal computer as an electronic apparatus including a vibrator using the tuning fork type vibrating piece 1 according to an embodiment of the present invention. 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 100. The display unit 1106 is rotated 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 using the tuning-fork type vibrating piece 1 as a reference signal source or the like.

  FIG. 7 is a perspective view schematically showing a configuration of a mobile phone (including PHS) as an electronic device including a vibrator using the tuning-fork type vibrating piece 1 according to the embodiment of the present invention. In this figure, a cellular phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and the display unit 100 is disposed between the operation buttons 1202 and the earpiece 1204. Such a cellular phone 1200 has a built-in vibrator using the tuning fork-type vibrating piece 1 as a reference signal source or the like.

  FIG. 8 is a perspective view schematically showing a configuration of a digital still camera as an electronic apparatus including a vibrator using the tuning-fork type vibrating piece 1 according to the embodiment of the present invention. 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 image sensor such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated. A display unit 100 is provided on the back of a case (body) 1302 in the digital still camera 1300, and is configured to display based on an imaging signal from the CCD. The display unit 100 displays an object as an electronic image. Functions as a viewfinder. 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 100 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 using the tuning-fork type vibrating piece 1 as a reference signal source or the like.

  The vibrator using the tuning fork type resonator element 1 according to the embodiment of the present invention is not limited to the personal computer shown in FIG. 6 (mobile personal computer), the cellular phone shown in FIG. 7, and the digital still camera shown in FIG. , For example, inkjet type ejection device (for example, inkjet printer), laptop personal computer, TV, video camera, video tape recorder, car navigation device, pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic Game equipment, word processor, workstation, video phone, security TV monitor, electronic binoculars, POS terminal, medical equipment (eg electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), Fish finder, various measuring instruments, instruments (for example , Gages for vehicles, aircraft, and ships), can be applied to electronic devices such as flight simulators.

[Moving object]
FIG. 9 is a perspective view schematically showing an automobile as an example of a moving body. The automobile 106 is equipped with a vibrator using the tuning fork type vibrating piece 1 according to the present invention. For example, as shown in the figure, an automobile 106 as a moving body has an electronic control unit 108 that is equipped with a vibrator using the tuning-fork type vibrating piece 1 and controls a tire 109 and the like mounted on a vehicle body 107. . In addition, vibrators using tuning fork type resonator element 1 include keyless entry, immobilizer, car navigation system, car air conditioner, anti-lock brake system (ABS), airbag, tire pressure monitoring system (TPMS). It can be widely applied to electronic control units (ECUs) such as tire pressure monitoring systems), engine controls, battery monitors for hybrid and electric vehicles, and vehicle body attitude control systems.

  DESCRIPTION OF SYMBOLS 1 ... Tuning fork type vibration piece as a vibration piece, 5 ... Vibrator, 6 ... Oscillator as an electronic device, 11, 12, 13 ... Vibration arm, 11a, 12a, 13a ... 1st surface, 14 ... Base part, 15, 16 , 17: Piezoelectric element, 15a, 16a, 17a ... Lower electrode film, 15b2, 16b2, 17b2 ... Piezoelectric film as an insulating layer, 15c, 16c, 17c ... Upper electrode film, 15 ', 16', 17 '... Piezoelectric element at the base, 15b ', 16b', 17b ', 17b2 ... Piezoelectric film at the base, 17b1 (15b1, 16b1) ... Insulating film, 17b1' (15b1 ', 16b1') ... Insulating film at the base, 18a, 18b, 18c ... connection part, 20 ... package, 21 ... package base, 22 ... lid, 23 ... inner bottom surface, 24, 26 ... electrode pad, 27, 28 ... external terminal, 29 ... contact Member 30 ... Adhesive 31 ... Metal wire 34 ... Internal terminal 36 ... Outer bottom surface 40 ... IC chip as oscillation circuit 41 ... Metal wire 106 ... Automobile as moving body 1100 ... Electronic device Personal computer, 1200... Cellular phone as electronic device, 1300... Digital still camera as electronic device.

Claims (11)

The base,
A vibrating arm extending from the base;
A lower electrode provided on the base and the vibrating arm;
An upper electrode provided above the lower electrode;
An insulating layer provided between the lower electrode and the upper electrode,
The resonator element according to claim 1, wherein a thickness of the insulating layer provided above the base is greater than a thickness of the insulating layer provided above the vibrating arm.   2. The resonator element according to claim 1, wherein a dielectric constant of the insulating layer provided above the base is smaller than a dielectric constant of the insulating layer provided above the vibrating arm. The base,
A vibrating arm extending from the base;
A lower electrode provided on the base and the vibrating arm;
An upper electrode provided above the lower electrode;
An insulating layer provided between the lower electrode and the upper electrode,
The resonator element according to claim 1, wherein a dielectric constant of the insulating layer provided above the base is smaller than a dielectric constant of the insulating layer provided above the vibrating arm. The vibrating arm includes a first vibrating arm and a second vibrating arm,
The lower electrode that extends from the first vibrating arm to the base, and the upper electrode that extends from above the second vibrating arm to above the base,
4. The resonator element according to claim 1, wherein the resonator element overlaps with the insulating layer interposed above the base portion. 5.   The resonator element according to claim 1, wherein the insulating layer includes a piezoelectric film.   6. The resonator element according to claim 1, wherein the base portion and the vibrating arm are made of quartz.   6. The resonator element according to claim 1, wherein the base portion and the vibrating arm are made of a semiconductor. A resonator element according to any one of claims 1 to 7,
A container containing the vibrating piece;
A vibrator characterized by comprising: A resonator element according to any one of claims 1 to 7,
A circuit element for driving the resonator element;
An electronic device comprising:   An electronic device comprising the resonator element according to claim 1.   A moving body comprising the resonator element according to claim 1.

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