JP2013186107A - Vibration piece and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration piece provided with a wiring structure that is free of occurrence of partial concentration of an electric field.SOLUTION: A vibration piece comprises: an element piece 23; a first electrode layer 46a1 provided on the element piece 23; a first piezoelectric layer 46a2 that is provided on the first electrode layer 46a1, has inclined surfaces on lateral surfaces and has a width wider than that of the first electrode layer 46a1; a second electrode layer 46a3 provided on the first piezoelectric layer 46a2; third electrode layers 46a4 that are provided on the inclined surfaces of the first piezoelectric layer 46a2 and are connected to the second electrode layer 46a3; and a fourth electrode layer 48 that is provided on the element piece 23 and is connected to one of the third electrode layers 46a4. When a shortest distance from an end portion of the first electrode layer 46a1 to one of the third electrode layers 46a4 is represented by A, a shortest distance from the end portion of the first electrode layer 46a1 to the fourth electrode layer 48 is represented by B and a shortest distance between the first electrode layer 46a1 and the second electrode layer 46a3 is represented by C, A, B and C satisfy relational expressions of C≤A and C≤B.

Description

  The present invention relates to a vibrating piece having a wiring structure having piezoelectric characteristics, and more particularly to a vibrating piece having a wiring structure suitable for forming a plurality of wirings on an element piece, and an electronic apparatus equipped with the vibrating piece. .

In recent years, electronic devices are becoming smaller and thinner, and the demand for smaller and thinner piezoelectric devices such as piezoelectric vibrators used as oscillation sources for various electronic devices is also increasing.
In the field of piezoelectric devices, for the purpose of further reducing the size and thickness of the vibrator, the use of a semiconductor material such as Si that can be easily microfabricated as a substrate has been promoted.

  For example, the piezoelectric devices disclosed in Patent Documents 1 and 2 are tuning-fork type angular velocity sensors, and a lower electrode layer, a piezoelectric layer, and an upper electrode layer are formed on one main surface of an element piece made of a semiconductor such as Si. Is formed. In the angular velocity sensor having such a configuration, the vibration arm is driven by vibrating in the direction parallel to the main surface of the element piece (in-plane vibration), and the vibration in the direction intersecting the main surface caused by the application of the angular velocity (surface). (External vibration) is detected. For this reason, in each of the pair of vibrating arms, two driving film portions and one detection film portion are formed on one main surface.

  In addition, the piezoelectric device disclosed in Patent Document 3 makes both the drive vibration and the detection vibration in-plane vibration by making the vibration arm that excites the drive vibration different from the vibration arm that vibrates when the angular velocity is applied. It is a thing.

JP 2008-14887 A JP 2008-128702 A JP 2009-156832 A

  If it is a piezoelectric device as disclosed in the above-mentioned patent document, it is certainly considered that it can contribute to miniaturization and thinning of the piezoelectric device. However, in the piezoelectric device disclosed in the patent document, the electrode layer disposed on the piezoelectric layer is dropped on the substrate side due to the structure of the laminated film used for driving or detection, and then the input / output electrodes Need to be connected. In such a configuration, in the portion where the upper electrode layer is dropped to the substrate side, the distance between the lower electrode layer and the upper electrode layer becomes close, and the electric field may concentrate here. If the electric field for generating the piezoelectric effect is concentrated on a part, drive loss and detection loss occur.

  Further, in the angular velocity sensor as disclosed in Patent Document 3, in order to improve the operating rate (bending efficiency) of the drive arm, a laminated film is also disposed at the tip of the transmission arm that becomes the connection portion of the drive arm. There is a request. Here, two pairs of line-shaped laminated films are disposed on the driving arm. For this reason, in order to connect any one of the line-shaped laminated films to the input / output electrode, it is necessary to straddle the other line-shaped laminated film.

  Even when straddling the line-shaped laminated film, if there is a place where the distance between the electrode serving as the upper electrode layer and the lower electrode layer of the line-shaped laminated film straddling is partially close, the electric field concentrates there and driving There is a risk of causing loss or the like.

  Therefore, in the present invention, even in a laminated film constituted by sandwiching the piezoelectric layer between the lower electrode layer and the upper electrode layer, even if the structure is such that the upper electrode layer straddles the piezoelectric layer, the electric field is partially applied. It is a first object of the present invention to provide a resonator element in which no concentration occurs. Furthermore, a second object of the present invention is to provide an electronic device equipped with this resonator element.

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] An element piece, a first electrode layer provided on the element piece, provided on a side opposite to the element piece side of the first electrode layer, having an inclined surface on a side surface, and A first piezoelectric layer wider than the first electrode layer, a second electrode layer provided on the opposite side of the first piezoelectric layer from the first electrode layer, and an inclined surface of the first piezoelectric layer A third electrode layer provided and connected to the second electrode layer; and a fourth electrode layer provided on the element piece and connected to the third electrode layer, the first electrode layer comprising: The shortest distance from the end of the first electrode layer to the third electrode layer is A, the shortest distance from the end of the first electrode layer to the fourth electrode layer is B, the first electrode layer and the second electrode A vibrating piece characterized by satisfying the relationship of C ≦ A and C ≦ B, where C is the shortest distance to the electrode layer.
According to the resonator element including the wiring structure having such a characteristic, the first piezoelectric layer that is the piezoelectric layer is sandwiched between the first electrode layer that is the lower electrode layer and the second electrode layer that is the upper electrode layer. Even when the second electrode layer has a structure in which the second electrode layer straddles the first piezoelectric layer via the third electrode layer and the fourth electrode layer, the electric field is partially concentrated. It never happens. Therefore, there is no possibility of causing a driving loss of the first piezoelectric layer. Further, when the first piezoelectric layer is used for detection, there is no risk of detection loss.

Application Example 2 The fifth electrode layer provided on the element piece, the second piezoelectric layer provided on the opposite side to the element piece side of the fifth electrode layer, and the second piezoelectric layer The sixth electrode layer provided on the opposite side to the fifth electrode layer, and the fourth electrode layer and the fifth electrode layer are connected to each other, according to Application Example 1, Vibrating piece.
According to the resonator element having such a feature, the fifth electrode layer, which is the lower electrode layer in one laminated film, and the second electrode layer, which is the upper electrode layer in the other laminated film, have one electrode at the same potential. Can be handled as

Application Example 3 The seventh piezoelectric layer has an inclined surface on a side surface, is provided on the inclined surface of the second piezoelectric layer, and is connected to the sixth electrode layer, and the element Application Example 2 characterized by comprising an eighth electrode layer provided on a piece and connected to the seventh electrode layer, wherein the first electrode layer and the eighth electrode layer are connected to each other. The vibrating piece described.
According to the resonator element having such a feature, the sixth electrode layer that is the upper electrode layer in one laminated film and the first electrode layer that is the lower electrode layer in the other laminated film are used as one electrode having the same potential. It becomes possible to handle.

Application Example 4 D is the shortest distance from the end of the fifth electrode layer to the seventh electrode layer, and E is the shortest distance from the end of the fifth electrode layer to the eighth electrode layer. The resonator element according to Application Example 3, wherein the shortest distance between the fifth electrode layer and the sixth electrode layer is F, and satisfies the relations F ≦ D and F ≦ E.
According to the resonator element having such a feature, the stack is configured by sandwiching the second piezoelectric layer that is the piezoelectric layer between the fifth electrode layer that is the lower electrode layer and the sixth electrode layer that is the upper electrode layer. Even when the sixth electrode layer has a structure in which the second piezoelectric layer is straddled across the seventh electrode layer and the eighth electrode layer, the electric field does not partially concentrate in the film. . Therefore, there is no possibility of causing a driving loss of the second piezoelectric layer. Further, when the second piezoelectric layer is used for detection, there is no risk of detection loss.

Application Example 5 The element piece includes a base and a vibrating arm protruding from the base, and in the width direction of the vibrating arm, the first electrode layer is on one side of the vibrating arm and the fifth is on the other side. 5. The resonator element according to any one of Application Examples 2 to 4, wherein an electrode layer is provided.
According to the resonator element having such a feature, the number of extraction electrodes can be reduced in addition to the effect according to the application example.

  [Application Example 6] An electronic apparatus in which the resonator element according to any one of Application Examples 1 to 5 is mounted.

FIG. 3 is a plan view illustrating a configuration of a resonator element according to the first embodiment. FIG. 2 is a partial cross-sectional enlarged view showing an example of a wiring structure according to the embodiment, and shows a configuration of a section A in FIG. FIG. 4 is a partial cross-sectional enlarged view showing another example of the wiring structure according to the embodiment, and shows a configuration of a section B in FIG. It is a sectional side view which shows the structure of the piezoelectric device which mounts the vibration piece which concerns on 1st Embodiment. It is a top view which shows the structure of the vibration piece which concerns on 2nd Embodiment. It is a top view which shows the structure of the vibration piece which concerns on 3rd Embodiment. It is a sectional side view which shows the structure of the piezoelectric device which mounts the vibration piece which concerns on 3rd Embodiment. It is a perspective view which shows the external appearance structure of the mobile telephone apparatus as an example of the electronic device which concerns on embodiment.

Hereinafter, embodiments of the resonator element and the electronic apparatus according to the invention will be described in detail with reference to the drawings.
First, a configuration example of the resonator element according to the invention is given, and a wiring structure that is a structural feature thereof will be described. FIG. 4 is a side sectional view showing an angular velocity sensor 10 as an example of a device on which the resonator element according to the invention is mounted.

  The angular velocity sensor 10 according to the present embodiment is configured based on a package 12, an IC 18, and a vibrating piece 22. The package 12 includes an IC 18, which will be described in detail later, and a base 14 having a cavity for accommodating the resonator element 22, and a lid 16 that seals the opening of the cavity in the base 14. Note that a plurality of terminals originally used for mounting the IC 18 and the resonator element 22 are formed in the base 14, but are omitted in FIG. 4.

The IC 18 is an integrated circuit including an oscillation circuit for driving a resonator element 22 whose details will be described later, an angular velocity detection circuit, and the like.
In the case of this embodiment, the vibration piece 22 employs a so-called WT type. As shown in FIG. 1, the resonator element 22 of this embodiment has a configuration in which a mounting base 24 is disposed at the center of the resonator element 22. For this reason, the angular velocity sensor 10 according to the present embodiment is mounted on the base 14 constituting the package 12 via the tab substrate 20 that enables lift support.

  The vibration piece 22 is configured based on the element piece 23, driving film portions (line-shaped laminated films) 44a, 44b, 46a, 46b, and detection film portions 40a, 40b. The element piece 23 is configured based on a base 24, detection arms 26a and 26b, transmission arms 28a and 28b, and drive arms 30a, 30b, 32a and 32b. The material of the element piece 23 may be a piezoelectric material such as quartz, lithium tantalate, lithium niobate, lithium borate, and barium titanate, as well as a non-piezoelectric material such as silicon and quartz. In the present embodiment, silicon is adopted as a constituent material of the element piece 23. This is because when silicon is employed, a resonator element having excellent vibration characteristics can be realized at a relatively low cost. In addition, silicon also has an advantage that element pieces can be formed with high dimensional accuracy by etching using a well-known fine processing technique.

  The base 24 is a part for disposing the input / output electrodes 36 and the extraction electrodes 38, 42a, 42b, and serves as a fixing part for the mounting substrate (in the present embodiment, the tab substrate 20). 23 at the center position. Although the form of the base 24 is not particularly limited, in the example illustrated in FIG. 1, the planar view shape is a rectangle.

  The detection arms 26 a and 26 b are vibration arms that play a role of generating vibration by applying an angular velocity to the element piece 23. The detection arms 26a, 26b are extended from the base 24 as a base point so as to have the same length as a pair on the + Y axis side and the −Y axis side.

  The transmission arms 28a and 28b are beam portions that connect the base 24 and drive arms 32a, 32b, 30a, and 30b, which will be described in detail later. The transmission arms 28a and 28b are extended from the base 24 so as to have the same length as a pair in the + X axis direction and the −X axis direction.

  The drive arms 30a, 30b, 32a, and 32b are vibration arms for generating drive vibration. The drive arms 30a, 30b, 32a, and 32b extend from the distal ends of the transmission arms 28b and 28a in parallel to the detection arms 26a and 26b in the + Y axis direction and the −Y axis direction, respectively. Mass bodies 34 used for frequency adjustment are provided at the tips of the detection arms 26a, 26b and the driving arms 30a, 30b, 32a, 32b, respectively.

  The detection arms 26a and 26b are provided with detection film portions 40a and 40b, and the drive arms 30a, 30b, 32a and 32b are provided with drive film portions 44a, 44b, 46a and 46b. Yes. Both the detection film portions 40a and 40b and the drive film portions 44a, 44b, 46a, and 46b are formed by a laminated structure including an electrode layer and a piezoelectric layer. Specifically, as shown in FIG. 2 and FIG. 3, the first electrode layer 46a1 and the fifth electrode layer 46b1, the first piezoelectric layer 46a2 and the second piezoelectric layer 46b2, and the second electrode layer 46a3 and the sixth electrode. The layer 46b3 is basically configured. 2 is an enlarged partial sectional view of a portion A in FIG. 1, and FIG. 3 is an enlarged partial sectional view of a portion B in FIG.

  The first electrode layer 46a1 and the fifth electrode layer 46b1 are the main parts of the element piece 23 (detection arms 26a and 26b, drive arms 30a, 30b, 32a, and 32b: FIGS. 2 and 3 show the drive arms 32a and 32b). It is arranged on the surface. The first piezoelectric layer 46a2 and the second piezoelectric layer 46b2 are disposed above the first electrode layer 46a1 and the fifth electrode layer 46b1, that is, on the side opposite to the element piece 23, respectively. The second electrode layer 46a3 and the sixth electrode layer 46b3 are provided on the opposite sides of the first piezoelectric layer 46a2 and the second piezoelectric layer 46b2 from the first electrode layer 46a1 and the fifth electrode layer 46b1, respectively. The transmission arm 28a has a first electrode layer 46a1 and a lead electrode 42a that electrically connect the second electrode layer 46a3 and the input / output electrode 36 disposed on the base 24 to constitute the driving film portion 46a. , 42b are disposed. By adopting such a configuration, the second electrode layer 46a3 and the sixth electrode layer 46b3 located on the upper side of the first piezoelectric layer 46a2 and the second piezoelectric layer 46b2, and the first electrode layer 46a1 located on the lower side, By applying a voltage between the fifth electrode layers 46b1, the first piezoelectric layer 46a2 and the second piezoelectric layer 46b2 can be contracted or expanded.

  As the electrode layer, for example, gold (Au), gold alloy, platinum (Pt), aluminum (Al), aluminum alloy, silver (Ag), silver alloy, chromium (Cr), chromium alloy, copper (Cu), Metal materials such as molybdenum (Mo), niobium (Nb), tungsten (W), iron (Fe), titanium (Ti), cobalt (Co), zinc (Zn), zirconium (Zr), ITO, ZnO, etc. It can be formed of a transparent electrode material.

Among these, as the constituent material of the electrode layer, it is preferable to use a metal (gold, gold alloy) or platinum mainly made of gold, and more preferably a metal (especially gold) mainly made of gold.
Gold is suitable as an electrode material because of its excellent conductivity (low electrical resistance) and excellent resistance to oxidation. In addition, gold has a feature that it can be patterned more easily by etching than platinum.

  Moreover, although the average thickness of an electrode layer is not specifically limited, For example, it is preferable that it is about 1-300 nm, and it is more preferable that it is 10-200 nm. Thereby, it is possible to make the electrode layer excellent in conductivity while preventing the electrode layer from adversely affecting the vibration characteristics of the resonator element.

As the piezoelectric layer, for example, zinc oxide (ZnO), aluminum nitride (AlN), lithium tantalate (LiTaO ₃ ), lithium niobate (LiNbO ₃ ), potassium niobate (KNbO ₃ ), lithium tetraborate (Li ₂ B ₄ O ₇ ), barium titanate (BaTiO ₃ ), PZT (lead zirconate titanate), and the like can be employed.

  Among these various materials, it is preferable to employ PZT. PZT has excellent c-axis characteristics. For this reason, the CI value of the resonator element can be reduced by configuring the piezoelectric layer with PZT as a main material. Moreover, these materials can be formed into a film by the reactive sputtering method.

  The average thickness of the piezoelectric layer employing such a constituent material is preferably 50 to 3000 nm, and more preferably 200 to 2000 nm. Accordingly, excellent vibration characteristics can be obtained while preventing the piezoelectric layer from adversely affecting the vibration characteristics of the resonator element.

  In the present embodiment, the detection film portions 40a and 40b and the drive film portions 44a, 44b, 46a, and 46b are arranged on one main surface of the element piece 23. Therefore, each detection arm 26a, 26b has two detection film portions 40a, 40b, and each drive arm 30a, 30b, 32a, 32b has two drive film portions 44a, 44b, 46a and 46b are disposed. Specifically, the detection film portions 40a and 40b or the drive film portions 44a, 44b, 46a, and 46b are disposed on both ends in the width direction of each arm. In such a configuration, with respect to the driving film portion 44a and the driving film portion 44b that form a pair provided on the driving arms 30a, 30b, 32a, and 32b, the driving film portion 46a and the driving film portion 46b By applying voltages of opposite polarities, the drive arms 30a, 30b, 32a, 32b can be bent in the + X axis direction or the -X axis direction. In addition, when the detection arms 26a and 26b are bent in the + X-axis direction or the -X-axis direction due to the application of the angular velocity, it is possible to obtain a charge corresponding to this.

  In the present embodiment, as shown in FIG. 1, driving film portions 44a, 44b, 46a, 46b disposed on the driving arms 30a, 32a extending to the + Y axis side, and extending to the −Y axis side. Driving film portions 44a, 44b, 46a, 46b disposed on the provided driving arms 30b, 32b are formed in a continuous line shape. This is because the bending rate of the drive arms 30a, 30b, 32a, 32b can be increased by adopting such an arrangement form.

  In the present embodiment, the driving film portions 44a, 44b, 46a, and 46b are arranged in this manner, so that at least one of them (in the example shown in FIG. 1, the one far from the base portion 24). The electrodes constituting the driving film portions 44b and 46b are configured to straddle either of the other driving film portions 44a and 46a (in the example shown in FIG. 1, closer to the base portion 24). Therefore, the fourth electrode layer 48 and the eighth electrode layer 50 are formed between the one driving film portion 44b, 46b and the other driving film portion 44a, 46a.

  As a detailed example, FIG. 2 and FIG. 3 show an intersecting form of the driving film portion 46a and the driving film portion 46b. In FIG. 1, the cross section taken along the broken line A is shown in FIG. 2, and the cross section taken along the arrow B is FIG.

  As shown in FIG. 2, a fourth electrode layer 48 and a third electrode layer 46a4 connecting the fifth electrode layer 46b1 constituting the driving film part 46b and the second electrode layer 46a3 constituting the driving film part 46a. Is provided. In the present embodiment, the first piezoelectric layer 46a2 is provided so as to be wider than the width of the first electrode layer 46a1. An inclined surface is provided on the side surface of the first piezoelectric layer 46a2 so as to widen the bottom. Therefore, a third electrode layer 46a4 is provided between the second electrode layer 46a3 and the fourth electrode layer 48 so as to travel along the inclined surface of the first piezoelectric layer 46a2. In the example shown in FIG. 2, the third electrode layer 46a4 is also connected to the extraction electrode 42b disposed on the transmission arm 28a via an inclined surface.

  Further, as shown in FIG. 3, the sixth electrode layer 46b3 of the driving film unit 46b is connected to the first electrode layer 46a1 of the driving film unit 46a via the seventh electrode layer 46b4 and the eighth electrode layer 50. In such a case, the first electrode layer 46a1 and the extraction electrode 42a can be electrically connected by extending the extraction electrode 42a to the lower portion of the first piezoelectric layer 46a2.

  With such a configuration, the sixth electrode layer 46b3 and the fifth electrode layer 46b1 constituting one driving film part 46b can straddle the other driving film part 46a without causing a short circuit. . Moreover, since it can be set as the structure which connects and puts together the electrode layer with the same polarity, the number of the extraction electrodes 42a and 42b arrange | positioned at the transmission arm 28a can be reduced.

Further, in order to protect the surfaces of the extraction electrodes 42a and 42b, the second electrode layer 46a3, the sixth electrode layer 46b3, the first piezoelectric layer 46a2, the second piezoelectric layer 46b2, the fourth electrode layer 48, and the eighth electrode layer 50. An insulating layer may be covered. Examples of the material of the insulating layer include Al ₂ O ₃ (aluminum oxide) and SiO ₂ (silicon dioxide).

  Further, in the present embodiment, the following characteristics are provided for a portion where one driving film portion 46b straddles the other driving film portion 46a. First, the shortest distance from the end in the width direction of the first electrode layer 46a1 to the inclined surface formed by the first piezoelectric layer 46a2, that is, the third electrode layer 46a4 is defined as A. Next, the shortest distance from the end in the width direction of the first electrode layer 46a1 to the fourth electrode layer 48 or the extraction electrode 42b corresponding to the fourth electrode layer 48 is defined as B. Next, the shortest vertical distance between the first electrode layer 46a1 and the second electrode layer 46a3, that is, the thickness of the first piezoelectric layer 46a2 is defined as C (see FIG. 2). The distances A, B, and C are determined so as to satisfy at least the relations C ≦ A and C ≦ B.

  By satisfying such an arrangement relationship, the distance between the first electrode layer 46a1 and the third electrode layer 46a4 or the fourth electrode layer 48 and the extraction electrode 42b on the side surface of the first piezoelectric layer 46a2 is shortened. There is no. When the distance between the first electrode layer 46a1 and the third electrode layer 46a4, or the fourth electrode layer 48 and the extraction electrode 42b becomes extremely short, the electric field concentrates on that portion, and driving loss may occur. is there. Therefore, by satisfying the relationship as described above, it is possible to prevent drive loss and obtain efficient bending vibration.

  Similarly to the above, in this embodiment, in FIG. 3, the shortest distance from the end in the width direction of the fifth electrode layer 46b1 to the inclined surface formed by the second piezoelectric layer 46b2, that is, the seventh electrode layer 46b4. Is defined as D. Next, the shortest distance from the end in the width direction of the fifth electrode layer 46b1 to the eighth electrode layer 50 is defined as E. Next, the shortest vertical distance between the fifth electrode layer 46b1 and the sixth electrode layer 46b3, that is, the thickness of the second piezoelectric layer 46b2 is defined as F. The distances D, E, and F are determined so as to satisfy at least the relations of F ≦ D and F ≦ E.

  By satisfying such an arrangement relationship, the distance between the fifth electrode layer 46b1 and the seventh electrode layer 46b4 is not shortened on the side surface of the second piezoelectric layer 46b2. When the distance between the fifth electrode layer 46b1 and the seventh electrode layer 46b4 becomes extremely short, the electric field concentrates on that portion, and drive loss may occur. Therefore, by satisfying the relationship as described above, it is possible to prevent drive loss and obtain efficient bending vibration.

  In the present invention, the first electrode layer 46a1, the eighth electrode layer 50, the seventh electrode layer 46b4, and the sixth electrode layer 46b3 may be formed as an integral electrode layer. Naturally, each electrode layer may be formed as a separate electrode layer, and the material, film thickness, etc. of the electrodes constituting each electrode layer may be varied. Similarly, both the second electrode layer 46a3, the third electrode layer 46a4, the fourth electrode layer 48, and the fifth electrode layer 46b1 can be selected as an integrated type or a separate type.

  Next, a second embodiment according to the piezoelectric device of the present invention will be described with reference to FIG. The piezoelectric device according to the present embodiment is different from the piezoelectric device according to the first embodiment described above in the form of the resonator element. Therefore, FIG. 5 shows only the resonator element that is the difference.

  The resonator element of the present embodiment is a so-called tuning fork type resonator element. In the angular velocity sensor having the resonator element 22a having such a configuration, a pair of driving film portions 56a and 56b and a single detection film portion 58a and 58b are disposed on each of the pair of vibrating arms 54a and 54b. Yes. The pair of driving film portions 56a and 56b are disposed at both ends in the width direction of the vibrating arms 54a and 54b, and the detection film portions 58a and 58b are disposed between the pair of driving film portions 56a and 56b, respectively. Has been. The driving film portions 56a and 56b and the detection film portions 58a and 58b are formed on the lower electrode layer (the first electrode layer 46a1 and the fifth electrode), as in the angular velocity sensor according to the first embodiment. Layer 46b1), the upper electrode layer (second electrode layer 46a3, sixth electrode layer 46b3), and piezoelectric layer (first piezoelectric layer 46a2, second piezoelectric layer 46b2).

  Even in the resonator element 22a having such a configuration, as shown in a portion indicated by a wavy line in FIG. 5, the lower electrode layer constituting the one driving film portion 56a (56b) and the other driving film An electrode layer 60 that connects the upper electrode layers constituting the portion 56b (56a) can be provided. In addition, by applying the wiring structure according to the present invention to the resonator element 22a having such a configuration, the base 52 that has conventionally occurred between the detection film portions 58a and 58b and the drive film portions 56a and 56b. It is possible to avoid the overlap of the extraction electrode 62 in FIG.

  In the above embodiments, the angular velocity sensor has been described as an example of the piezoelectric device. However, the piezoelectric device to which the wiring structure according to the present invention can be applied may be a vibrator 10a (see FIG. 7) including the vibrating piece 22b as shown in FIG.

  The vibrator 10 a according to the present embodiment is configured based on a package 12 including a base 14 and a lid 16, and a vibrating piece 22 b housed in the package 12. As shown in FIG. 6, the resonator element 22 b according to the present embodiment is a resonator element having a so-called tuning fork shape. That is, a base 52 and a pair of vibrating arms 54a and 54b extending from the base 52 as a base point are provided.

  A pair of driving film portions 56a and 56b are disposed on the vibrating arms 54a and 54b, respectively. The pair of driving film portions 56a and 56b are disposed at both ends in the width direction of the vibrating arms 54a and 54b. The driving film portions 56a and 56b are arranged on the lower side electrode layers (first electrode layer 46a1 and fifth electrode layer 46b1) and on the upper side, like the angular velocity sensors according to the first and second embodiments. The electrode layer (the second electrode layer 46a3, the sixth electrode layer 46b3) and the piezoelectric layer (the first piezoelectric layer 46a2, the second piezoelectric layer 46b2) located in the base. That is, when the first electrode layer 46a1 (not shown) is disposed on one side of the vibrating arms 54a and 54b in the width direction, the fifth electrode layer 46b1 is disposed on the other side. The pair of resonating arms 54a and 54b has a line-symmetric arrangement relationship with a longitudinal center line (not shown) as a starting point.

  Even with the resonator element 22b having such a configuration, as shown in the part indicated by the wavy line in FIG. 6, the lower electrode layer constituting one drive film portion 56a (56b) and the other drive film An electrode layer 60 that connects the upper electrode layers constituting the portion 56b (56a) can be provided.

Next, an electronic device equipped with the angular velocity sensor having the above-described configuration and the resonator element constituting the vibrator will be described. FIG. 8 is a diagram illustrating a mobile phone including the vibrator described in the above embodiment as a transmission source.
As an external configuration of the mobile phone 100 illustrated in FIG. 8, a liquid crystal display device 104, a plurality of operation buttons 106, an earpiece 102, and a mouthpiece 108 can be given.

  Note that the electronic device according to the present invention is not limited to a mobile phone, but includes a personal computer, an inkjet discharge device, a television, an electronic dictionary, a calculator, a car navigation system that requires an attitude control function, an aircraft, a robot, a ship, a vehicle, Electronic game machines, motion controllers, head mounted displays, PDR (pedestrian position and direction measurement), game controllers, digital cameras having a camera shake prevention function, digital video cameras, and the like are also included.

10 ......... Angular velocity sensor, 12 ......... Package, 14 ......... Base, 16 ......... Lid, 18 ......... IC, 20 ......... Tab substrate, 22 ......... Vibration piece, 23 ......... Element Piece, 24 ......... Base, 26a ... Detection arm, 26b ... Detection arm, 28a ... Transmission arm, 28b ... Transmission arm, 30a ... Drive arm, 30b ... Drive arm, 32a ......... driving arm, 32b ......... driving arm, 34 ......... mass body, 36 ......... input / output electrode, 38 ......... extraction electrode, 40a ......... detection film part, 40b ......... detection Film part, 42a ... Extraction electrode, 42b ... Extraction electrode, 44a ... Drive film part, 44b ... Drive film part, 46a ... Drive film part, 46a1 ... 1 electrode layer, 46a2 ......... first piezoelectric layer, 46a3 ......... second electrode layer, 46a4 ......... third electrode layer, 46b ...... Drive film portion, 46b1 ......... Fifth electrode layer, 46b2 ......... Second piezoelectric layer, 46b3 ......... Sixth electrode layer, 46b4 ......... Seventh electrode layer, 48 ......... Fourth electrode Layer, 50 ......... Eighth electrode layer.

Claims (6)

An element piece;
A first electrode layer provided on the element piece;
A first piezoelectric layer provided on a side opposite to the element side of the first electrode layer, having an inclined surface on a side surface, and wider than the first electrode layer;
A second electrode layer provided on the opposite side of the first piezoelectric layer from the first electrode layer side;
A third electrode layer provided on the inclined surface of the first piezoelectric layer and connected to the second electrode layer;
A fourth electrode layer provided on the element piece and connected to the third electrode layer,
The shortest distance from the end of the first electrode layer to the third electrode layer is A, the shortest distance from the end of the first electrode layer to the fourth electrode layer is B, the first electrode When the shortest distance between the layer and the second electrode layer is C,
C ≦ A and C ≦ B
A vibrating piece characterized by satisfying the relationship A fifth electrode layer provided on the element piece;
A second piezoelectric layer provided on the opposite side of the element side of the fifth electrode layer;
A sixth electrode layer provided on the opposite side of the second piezoelectric layer from the fifth electrode layer,
The resonator element according to claim 1, wherein the fourth electrode layer and the fifth electrode layer are connected. The second piezoelectric layer has an inclined surface on a side surface, is provided on the inclined surface of the second piezoelectric layer, and is connected to the sixth electrode layer;
An eighth electrode layer provided on the element piece and connected to the seventh electrode layer;
The resonator element according to claim 2, wherein the first electrode layer and the eighth electrode layer are connected. D is the shortest distance from the end of the fifth electrode layer to the seventh electrode layer, E is the shortest distance from the end of the fifth electrode layer to the eighth electrode layer, and the fifth electrode. When the shortest distance between the layer and the sixth electrode layer is F,
F ≦ D and F ≦ E
The vibration piece according to claim 3, wherein the relationship is satisfied. The element piece includes a base and a vibrating arm protruding from the base,
5. The method according to claim 2, wherein in the width direction of the vibrating arm, the first electrode layer is provided on one side of the vibrating arm, and the fifth electrode layer is provided on the other side. 6. The vibrating piece described.   An electronic device comprising the resonator element according to claim 1.

Images