JP2012029024A - Bending vibration piece, vibrator, oscillator, and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bending vibration piece which prevents exposure defects occurred when an electrode pattern is formed and achieves high reliability and yield.SOLUTION: The bending vibration piece comprises: a base 14; vibration arms 16 (16a to 16c) extending from the base 14 serving as a base end; a laminate which is located above the vibration arms 16 and includes at least a first electrode 20, a second electrode 38 to which a voltage having an electrical potential different from that of the first electrode 20, is applied; and a piezoelectric layer 28 provided between the first electrode 20 and the second electrode 38. A widened part is provided at the base end of each vibration arm 16, and at least a side surface of the widened part includes a metal film. It is preferable to form the metal film as a part of the first electrode 20.

Description

  The present invention relates to a resonator element bending device, an oscillator, an oscillator, and an electronic device, and more particularly to a resonator element that excites bending vibration in an out-of-plane direction (normal direction with respect to a main surface), and an oscillator equipped with the resonator element. Further, the present invention relates to an oscillator, and an electronic device equipped with these vibrators and oscillators.

In the resonator element that excites bending vibration, a temperature difference occurs between the compression part where the compressive stress of the vibrating arm acts and the extension part where the tensile stress acts, and vibration is also caused by heat conduction acting to alleviate this temperature difference. Energy loss occurs. The decrease in the Q value generated by this heat conduction is called a thermoelastic loss effect (hereinafter referred to as thermoelastic loss). Therefore, it is necessary to design in consideration of thermoelastic loss. For example, according to the technique disclosed in Patent Document 1, it is understood that the Q value indicating the stability of resonance can be improved by providing a groove in the arm portion of the crystal resonator.
However, as the electronic device becomes smaller and thinner, it becomes very difficult to accurately form the groove in the vibrating portion as the vibrating piece becomes smaller and thinner.

  As means for avoiding such problems, it has been devised to make the vibration part thinner and to form a piezoelectric layer on the vibration part (Patent Documents 2-4). In the resonator element having such a configuration, an electric field having a different potential is applied to the front and back of the piezoelectric layer to excite vibrations in a direction (out-of-plane direction or normal direction) intersecting the surface on which the piezoelectric layer is formed. be able to.

Japanese Utility Model Publication No. 2-3322 JP 2009-5022 A JP 2009-5023 A JP 2009-5024 A

  When the resonator element configured as disclosed in Patent Documents 2 to 4 is used, thermoelastic loss due to bending of the vibration part can be suppressed. By the way, the resonator element configured as disclosed in Patent Documents 2 to 4 has a problem that stress is increased at the proximal end portion of the vibrating arm during bending vibration, and vibration efficiency is deteriorated. In order to solve such a problem, a means is generally taken to widen the base end portion of the vibrating arm to form a widened portion and relieve stress. The resonator element configured as disclosed in Patent Documents 2-4 uses a light-transmitting member, particularly quartz, on the substrate, and the electrode is formed only on the first surface on which the piezoelectric layer is formed. Yes. For this reason, at the time of pattern formation by photolithography, exposure is performed by irradiating reaction light from above the first surface. When the widened portion is formed on the vibrating arm as described above, the crystal structure of the crystal at the base end portion Accordingly, the surface of the metal film of the widened portion is inclined in a plurality of directions. When a resist is applied on the metal film and exposed, the reaction light irradiated to the side surface of the substrate, particularly the widened portion of the vibrating arm, is diffusely reflected from the metal film, and may be irradiated to the resist film from the side surface direction ( (See FIG. 13). In FIG. 13, FIG. 13A is a diagram illustrating a planar configuration of the resonator element, and FIG. 13B is a diagram illustrating a partially enlarged perspective view of a circular portion in FIG. FIG. 14A shows a cross section taken along the line AA ′ in FIG. 13B, and FIG. 14B shows a cross section taken along the line BB ′ in FIG. 13B.

  The above description can be described in detail as follows. In the vibrating piece forming step, first, as shown in FIGS. 14A and 14B, a metal film is formed over the entire circumference of the vibrating arm, and a resist film is formed thereon. Then, exposure is performed by applying a mask to a portion to be left as the first electrode (base electrode). At this time, normally, as shown in FIG. 14B, the reaction light is not irradiated on the portion of the resist film which is shaded by the mask. For this reason, the shadowed portion is not exposed and remains as a protective film even after development. On the other hand, in the widened portion shown in FIG. 14A, which is the widened portion, the reaction light irregularly reflected on the metal film formed along the complex crystal plane is applied to the resist film in the shadowed portion by the mask. On the other hand, it may enter from the side surface direction, causing unexpected exposure to the resist film.

  Such a phenomenon often occurs when patterning the first electrode (electrode formed before forming the piezoelectric layer), and the resist film that should protect the metal film in the electrode forming portion is removed during development. If this happens, problems such as electrode disconnection may occur.

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 base, a vibrating arm extending from the base as a base, and a second electrode disposed on the vibrating arm and applied with a voltage having a different potential from the first electrode and the first electrode And a laminate including at least a piezoelectric layer provided between the first electrode and the second electrode, and a widened portion is provided at the base end of the vibrating arm, A flexural vibration piece comprising a light shielding film on a side surface.

  By adopting such a configuration, unnecessary exposure of the resist film due to the influence of irregular reflection can be prevented, and the defective shape of the electrode pattern can be suppressed. Thereby, the increase in the parasitic vibration mode can be suppressed, and a highly reliable vibration piece can be obtained. In addition, since yield defects are suppressed, the yield can be improved.

Application Example 2 The bending vibration piece according to Application Example 1, wherein the light shielding film is configured by the first electrode.
With such a configuration, the first electrode can have both a role as an electrode and a role as a light shielding film. Therefore, it is not necessary to separately form a light shielding film, and high productivity can be maintained.

Application Example 3 The bending vibration piece according to Application Example 1, wherein the light shielding film is an electrically floating metal film.
With such a configuration, the light shielding film can be made indeterminate by being electrically separated while being formed simultaneously with the first electrode. This eliminates the need for the shape of the first electrode to be constrained by the light-shielding film arrangement system, and can improve the degree of freedom in design.

Application Example 4 A vibrator having the flexural vibration piece according to any one of Application Examples 1 to 3 and a package in which the vibration piece is mounted.
According to such a configuration, the parasitic vibration mode in the bending vibration piece can be suppressed, and high performance and high reliability can be obtained.

Application Example 5 Internally includes the bending vibration piece according to any one of Application Examples 1 to 3, an oscillation circuit that controls oscillation of the bending vibration piece, at least the vibration piece, and the electronic component. An oscillator comprising a package to be mounted on.
According to such a configuration, the parasitic vibration mode in the bending vibration piece can be suppressed, and high performance and high reliability can be obtained.

[Application Example 6] An electronic apparatus in which the bending vibration piece according to any one of Application Examples 1 to 3 is mounted.
With such a configuration, it is possible to cope with downsizing of electronic devices.

It is a figure which shows the structure of the vibration piece which concerns on 1st Embodiment. FIG. 3 is an exploded perspective view illustrating a configuration of a resonator element according to the first embodiment. 5 is a partially enlarged perspective view of the resonator element according to the first embodiment. FIG. It is a partial expansion perspective view which shows the form at the time of exposure at the time of forming a 1st layer excitation electrode. It is a figure for demonstrating the manufacturing process of the vibration piece which concerns on embodiment. It is a figure which shows the structure of the vibration piece which concerns on 2nd Embodiment. FIG. 6 is a partially enlarged perspective view of a resonator element according to a second embodiment. It is a figure which shows the structure of the vibration piece which concerns on 3rd Embodiment. It is a figure which shows the structure of the vibrator | oscillator which mounted the vibration piece which concerns on embodiment. It is a figure which shows the structure of the oscillator which mounted the resonator element which concerns on embodiment, and the electronic component provided with the circuit which oscillates this resonator element. It is a figure which shows the mobile telephone as an example of the electronic device carrying at least one of the vibrator | oscillator which concerns on embodiment, or an oscillator. It is a figure which shows the personal computer as an example of the electronic device carrying at least one of the vibrator | oscillator which concerns on embodiment, or an oscillator. It is a figure which shows the mode of the reaction light irradiated to a resist film, and irregular reflection. It is a figure which shows the mode at the time of exposure in the AA 'cross section in FIG. 13, and a BB' cross section.

Hereinafter, embodiments of the flexural vibration piece, the vibrator, the oscillator, and the electronic apparatus according to the invention will be described in detail with reference to the drawings.
First, the resonator element according to the first embodiment will be described with reference to FIGS. 1 to 3. In FIG. 1, FIG. 1A is a plan view of the resonator element, and FIG. 1B is a diagram illustrating a part of the AA ′ cross section in FIG. ) Is a diagram showing a part of a BB ′ cross section in FIG. FIG. 2 is an exploded perspective view of the resonator element. Further, FIG. 3 is a partially enlarged perspective view showing the base end portion of the vibrating arm in the vibrating piece. As shown in FIG. 2, the flexural vibration piece according to the present embodiment (hereinafter simply referred to as the vibration piece 10) includes a substrate 12, a piezoelectric layer 28, a first electrode 20, and a second electrode 38.

  The substrate 12 is made of, for example, quartz, and includes a base portion 14 and a plurality (three in the form shown in FIGS. 1 and 2) of vibrating arms 16 (16a to 16c) extending from the base portion 14 as a base end. Become. In the case of the example according to the embodiment, the base 14 is formed to be thicker than the vibrating arm 16 and is configured to be able to maintain the mechanical strength during mounting. On the other hand, the resonating arm 16 is formed thinner than the base portion 14, and the thermoelastic loss during vibration is suppressed. Further, the resonating arm 16 has a widened portion 300 (300a to 300c) at a base end portion which is a connecting portion with the base portion 14, and ensures resistance to stress caused by bending vibration. The substrate 12 according to the embodiment configured to have a thickness different between the base portion 14 and the vibrating arm 16 includes a first surface in which the base portion 14 and the vibrating arm 16 are continuously flattened, and the base portion 14 and the vibrating arm 16. And a second surface formed with a step between them. The first surface formed in this manner is a surface along a direction intersecting (orthogonal) with the bending direction of the vibrating arm 16, and the second surface is a surface facing the first surface. When the substrate 12 is made of quartz, the cut angle of the base plate 12a (see FIG. 5) when forming the substrate 12 is preferably a Z-cut, but may be an X-cut or an AT-cut. good. Since the substrate 12 according to the embodiment is not a target to which a voltage is directly applied, basically the cut angle does not affect the vibration characteristics. However, when the base plate 12a cut out by the Z cut is used, it is possible to obtain a characteristic that the processing becomes easy. The substrate 12 is not limited to quartz but may be a substrate using an equivalent material such as a silicon substrate, a quartz substrate, or a glass substrate.

The first electrode 20, the piezoelectric layer 28, and the second electrode 38 are laminated with the first surface of the substrate 12 as a main component. Here, the first electrode 20 is an electrode formed before the piezoelectric layer 28 is formed, and the second electrode 38 is an electrode formed after the piezoelectric layer 28 is formed. Therefore, the expressions such as the first electrode 20 and the second electrode 38 are not related to the potential at each electrode. As a material for forming the first electrode 20 and the second electrode 38, it is preferable that the first electrode 20 and the second electrode 38 have good adhesion to the crystal serving as the substrate 12 and facilitate the orientation of the piezoelectric layer 38. Examples of materials that are versatile as electrode members include Au, Pt, Al, Ag, Cu, Mo, Cr, Nb, W, Ni, Fe, Ti, Co, Zn, and Zr. In the present embodiment, both the first electrode 20 and the second electrode 38 are formed of a metal layer having a two-layer structure in which the lower layer is Cr and the upper layer is Au. Further, examples of the piezoelectric layer 28 include ZnO, AlN, PZT, LiNbO ₃ , KNbO _3, etc., and in this embodiment, AlN is mainly adopted.

  The first electrode 20 includes, for example, first layer excitation electrodes 22a, 22b, and 22c, first layer extraction electrodes 24 and 26, and an input / output electrode 42. In the case of the resonator element 10 according to the embodiment, the first layer excitation electrodes 22a, 22b, and 22c extend from the vicinity of the middle part of the vibrating arm 16 to the widened portions 300a, 300b, and 300c provided at the base end portion. It is formed so as to surround the periphery. With such a configuration, the side surfaces 310a, 310b, and 310c of the widened portion are covered with the mask, so that no exposure reaction light is incident. In other words, it is possible to prevent irregular reflection of light entering from the side surfaces 310a to 310c of the widened portion. Here, the first layer excitation electrode 22 a, the first layer excitation electrode 22 c, and the input / output electrode 42 are at the same potential and are connected by the first layer extraction electrode 24. On the other hand, the first layer excitation electrode 22b is in an electrically floating state and is connected to a first layer extraction electrode 26 for connection to a second electrode 38, which will be described in detail later.

  The piezoelectric layer 28 is formed so as to cover the first surface forming portion of the first electrode 20 described above. Specifically, it includes excitation electrode covering portions 30 a, 30 b, 30 c formed on the vibrating arms 16 a, 16 b, 16 c and an extraction electrode covering portion 32 formed on the base portion 14. The lead electrode covering portion 32 is provided with openings 34 and 36 for electrically connecting the above-described first electrode 20 and a second electrode 38 to be described in detail later. The piezoelectric layer 28 is applied with voltages having different potentials on the front and back surfaces thereof, so that it is in the out-of-plane direction (direction intersecting the piezoelectric layer 28 forming surface: normal direction to the piezoelectric layer forming surface). It has the property of bending to the side.

  The second electrode 38 includes, for example, second layer excitation electrodes 40a, 40b, and 40c, second layer extraction electrodes 46 and 48, and an input / output electrode 44. Here, the second layer excitation electrode 40b is connected to the second layer extraction electrode 46, and the second layer extraction electrode 46 is connected to the first layer extraction electrode via the opening 34 formed in the piezoelectric layer 28 described above. 24 is electrically connected. Therefore, the same potential voltage is applied to the first layer excitation electrodes 22a and 22c and the second layer excitation electrode 40b. On the other hand, the second layer excitation electrodes 40 a and 40 c and the input / output electrode 44 are applied with the same potential voltage, but the second layer extraction electrode 48 is cut off via the second layer extraction electrode 46. Are not directly connected. However, the second layer extraction electrode 48 is electrically connected to the first layer extraction electrode 26 via the opening 36 formed in the piezoelectric layer 28 described above, and the first layer extraction electrode 26 and the second layer The second layer excitation electrodes 40a and 40c, the first layer excitation electrode 22b, and the input / output electrode 44 are electrically connected via the extraction electrode 48. In FIGS. 1 and 2, a part of the first layer extraction electrodes 24 and 26 and a part of the second layer extraction electrodes 46 and 48 to which voltages having different potentials are applied are overlapped. Although shown, the extraction electrodes having different potentials are actually designed so as not to overlap on the front and back surfaces of the piezoelectric layer 28. This is to suppress excitation at locations other than the vibrating arm 16.

  In the resonator element 10 having such a configuration, the excitation electrode forming portion of the vibrating arm 16 is covered with the first layer excitation electrode 22. For this reason, in the photolithography process at the time of electrode pattern formation, there is no risk that the resist film will be unnecessarily exposed due to the wraparound of light due to irregular reflection, the electrode pattern has a poor shape, and the accompanying increase in parasitic vibration mode, etc. Can be suppressed. Therefore, it is possible to provide a high-yield and low-cost vibration piece having good vibration characteristics.

  FIG. 3 shows a partially enlarged perspective view of the configuration of the base end portion of the vibrating arm 16 in the resonator element 10 having the above-described configuration, and FIG. 4 shows a diagram of a process for forming the first layer excitation electrode 22. According to FIGS. 3 and 4, the first layer excitation electrode 22 covers the side surfaces 310 a to 310 c of the widened portions 300 a to 300 c of the vibrating arm 16 with shadows by the mask. For this reason, it turns out that the irregular reflection in the metal film formed in the wide part 300a-300c formed along a complicated crystal structure is suppressed, and it becomes possible to suppress the wraparound of reaction light reliably.

  Next, a manufacturing process of the resonator element 10 according to the present embodiment will be described with reference to FIG. First, a base plate 12a that serves as a basis for the resonator element 10 is prepared. In the present embodiment, quartz is adopted as the base plate 12a. The base plate 12a may be silicon, quartz, glass, or the like. When the base plate 12a is made of quartz, the thickness is desirably about 50 to 100 μm (see FIG. 5A).

  Next, a part of the base plate 12a is thinned to form a thin part 12b. The thinning may be performed by etching using buffered hydrofluoric acid (BHF) or the like. Etching is performed from the second surface (see FIG. 5B).

  After thinning, the outer shape of the substrate 12 is formed. When forming the outer shape, it is desirable to perform etching from the first surface side. Note that BHF may be used for etching (see FIG. 5C).

  After finishing the outer shape of the substrate 12, the first electrode 20 is formed on the first surface and the outer peripheral surfaces of the vibrating arms 16a, 16b, and 16c. The first electrode 20 is formed by first forming a metal layer on the first surface, the second surface, and the entire side surface of the substrate 12. The metal layer may be formed using a technique such as magnetron sputtering. After forming the metal layer, a resist is applied to the entire surface. Thereafter, the metal layer is etched by a photolithography method to obtain a metal pattern along the shape of the first electrode 20. At this time, the metal pattern is left on the side surfaces 310a to 310 of the widened portion provided in the vibrating arms 16a to 16c as described above.

  After the first electrode 20 is formed, the piezoelectric layer 28 is formed at a desired location. First, a piezoelectric layer is formed on the entire first surface of the substrate including the first electrode 20. The piezoelectric layer is formed using a reactive RF sputtering method. In the case where the piezoelectric layer is made of AlN, the thickness of the piezoelectric layer is preferably in a range of about 2000 mm to 10,000 mm (see FIG. 5D).

  Next, the piezoelectric layer is formed into a desired pattern by patterning the resist by photolithography and wet etching. When the piezoelectric layer is made of AlN, a strong alkaline aqueous solution is used as an etchant for wet etching. An example of the strong alkaline aqueous solution is tetramethylammonium hydroxide. Alternatively, an acid-based etching solution obtained by heating phosphoric acid may be used.

  After the formation of the shape of the piezoelectric layer 28 is completed, the second electrode 38 (see FIG. 2) is formed. As with the formation of the first electrode 20, the second electrode 38 may be formed by forming a metal layer on the entire first surface, patterning a resist by photolithography, and forming a shape by wet etching (FIG. 5 (E)).

  In the said embodiment, it described that the board | substrate 12 was comprised with quartz. However, the resonator element 10 according to the present embodiment excites vibrations in the out-of-plane direction by the piezoelectric layer 28. For this reason, the material of the substrate 12 may be a member other than quartz. Specifically, a piezoelectric body other than quartz may be used, or a semiconductor such as silicon may be used.

In the above embodiment, the second electrode 38 is directly formed on the upper surface of the piezoelectric layer 28. However, in the resonator element 10 according to the present embodiment, an insulating layer (insulating film) may be formed between the piezoelectric layer 28 and the second electrode 38 (not shown). By adopting such a configuration, it is possible to prevent a short circuit between the first electrode 20 and the second electrode 38 even when the through hole is formed in the piezoelectric layer 28. In addition, as a film thickness of an insulator layer, it is desirable to set it as 50 nm or more from a viewpoint of short circuit prevention. On the other hand, from the viewpoint of suppressing the deterioration of the characteristics of the piezoelectric layer 28, the thickness is desirably 500 nm or less. Here, the insulator layer may be made of SiO ₂ or SiN _X.

Furthermore, a protective layer (inorganic film) may be formed on the second surface of the vibrating arm 16 in the vibrating piece 10 according to the above embodiment (not shown). In particular, silicon dioxide (SiO ₂ ) is known to have a negative temperature characteristic, and this can be used to correct the frequency temperature characteristic.

  Next, a second embodiment according to the resonator element of the invention will be described in detail with reference to FIG. The basic configuration of the resonator element according to this embodiment is the same as that of the resonator element 10 according to the first embodiment described above. The detailed description will be omitted. 6A is a plan view of the resonator element, and FIG. 6B is a diagram illustrating a part of the AA ′ cross section in FIG. 6A. ) Is a diagram showing a part of a BB ′ cross section in FIG.

  The resonator element 110 according to this embodiment is also configured based on the substrate 112, the first electrode 120, the piezoelectric layer 128, and the second electrode 138. The configuration of the substrate 112 is the same as that of the resonator element 110 according to the first embodiment described above.

  In the resonator element 110 according to this embodiment, the formation range of the piezoelectric layer 128 is narrower than that of the resonator element 10 according to the first embodiment. Specifically, the first surface from the intermediate portion to the widened portion of each vibrating arm 116a, 116b, 116c is configured to be covered.

  As the piezoelectric layer 128 has such a configuration, the arrangement of the first electrode 120 and the second electrode 138 is also changed. Specifically, as shown in FIG. 6B, the first electrode 120 is disposed on both side surfaces of the vibrating arms 116a, 116b, and 116c at the base end portions of the vibrating arms 116a, 116b, and 116c that are widened portions. It is configured. By adopting such a configuration, unnecessary exposure of the resist film accompanying wraparound due to irregular reflection of reaction light in the photolithography process can be prevented. Here, the two first electrodes 120 formed on both side surfaces of the vibrating arms 116a, 116b, and 116c have different potentials as electrodes. For example, in FIG. 6B, when a positive potential voltage is applied to the left first electrode 120 in the drawing, a negative potential voltage is applied to the right first electrode 120 in the drawing. Become.

  In order to realize such an electrode pattern arrangement, at the base 114 of the substrate 112, the extraction electrode 124 to which voltages having different potentials are applied and a part of the extraction electrode 146 cross each other. For this reason, the insulating film 131 is disposed at the intersection. This is because a short circuit between electrode patterns having different potentials can be prevented.

  The second electrode 138 at the base end portion is disposed so as to be stacked on the first electrode 120 disposed on the right side in the drawing (see FIG. 6B). With such a configuration, the second electrode 138 formed after forming the piezoelectric layer 128 and the first electrode 120 formed before forming the piezoelectric layer 128 are electrically connected as will be described in detail later. Can be connected.

In the vicinity of the excitation portions in the vibrating arms 116a, 116b, and 116c, as shown in FIG. 6C, the first electrode 120 covers the left side in the drawing of the vibrating arms 116a, 116b, and 116c, and the first layer excitation electrode. 122a, 122b, 122c are configured. On the other hand, the second electrode 138 forms the second layer excitation electrodes 140a, 140b, and 140c while covering the right side of the vibrating arms 116a, 116b, and 116c in the drawing. FIG. 7 shows a partially enlarged perspective view of the configuration of the base end portion of the vibrating arms 116a, 116b, 116c in the vibrating piece 110 having such a configuration. According to FIG. 7, the first electrode 120 covers the side surfaces 310 a to 310 c of the widened portions 300 a to 300 c of the vibrating arms 116 a, 116 b, 116 c, and it is possible to reliably suppress the wraparound of the reaction light due to irregular reflection. I understand that there is.
About another structure, an effect | action, and an effect, it is the same as that of the vibration piece 10 which concerns on 1st Embodiment mentioned above.

  Next, a third embodiment according to the resonator element of the invention will be described in detail with reference to FIG. Most configurations of the resonator element according to the present embodiment are the same as those of the resonator element 10 according to the first embodiment described above. Therefore, parts having the same functions are denoted by reference numerals obtained by adding 200 to the drawings, and detailed description thereof will be omitted. 8A is a plan view of the resonator element, and FIG. 8B is a diagram showing a part of the AA ′ cross section in FIG. 8A. ) Is a diagram showing a part of a BB ′ cross section in FIG.

  In the resonator element 210 according to the present embodiment, the first electrode 220 formed on the base end portion of the vibrating arms 216a, 216b, and 216c is divided, and one of them is electrically floated (undefined potential) and the metal film 221. It is characterized by the points. Specifically, the right electrode in FIG. 8B is the first electrode 220 electrically connected to the input / output electrode 242 or the input / output electrode 244. On the other hand, the metal film 221 disposed on the left side in the drawing is a metal film with an indefinite potential that is not electrically connected to any of the input / output electrodes 242 and 244.

  The second electrode 238 is formed on the top of the piezoelectric layer 228, and can have substantially the same shape as the second electrode 38 in the resonator element 10 according to the first embodiment. In the resonator element 210 according to the present embodiment, the first electrode 220 is routed only to the first surface side in the excitation portions of the vibrating arms 216a, 216b, 216c to form the first layer excitation electrodes 222a, 222b, 222c. At the same time, second layer excitation electrodes 240a, 240b, 240c are formed on the upper surface of the piezoelectric layer 228 so that the side surfaces of the vibrating arms 216a, 216b, 216c are not covered with metal films. By covering the forked portion where irregular reflection is most likely to occur with the first electrode 220 and the metal film 221, most of the problems caused by irregular reflection during the photolithography process can be eliminated. Therefore, even if it is a case where it is such a structure, there can exist an effect similar to the vibrating bars 10 and 210 which concern on the 1st, 2nd embodiment mentioned above.

Next, an embodiment according to the vibrator of the present invention will be described with reference to FIG. The vibrator 50 according to the present embodiment includes a vibrating piece and a package 52 in which the vibrating piece is mounted.
As the resonator element, the resonator element according to the first to third embodiments (in this embodiment, the resonator element 10, 110, 210 is representatively referred to as the resonator element 10) is employed. The package 52 is configured based on a package base 54 and a lid 56. The package base 54 has a box shape and includes the resonator element mounting terminal 60 inside. On the other hand, an external mounting terminal 62 electrically connected to the resonator element mounting terminal 60 is provided on the outer bottom surface of the package base 54.

  The package base 54 having such a configuration may be formed of an insulating member. For example, the package base 54 can be formed by laminating a flat plate and a frame-shaped ceramic green sheet and firing them. The resonator element mounting terminal 60 and the external mounting terminal 62 can be formed by screen printing on a ceramic green sheet.

  The lid 56 may be a flat plate made of metal or glass. As a constituent material of the lid 56, a material whose linear expansion coefficient approximates that of the constituent material of the package base 54 is desirable. This is to suppress the occurrence of cracks and peeling due to temperature changes. When the package base 54 is made of ceramic, it is preferable to use kovar (alloy) or soda glass.

  For joining the package base 54 and the lid 56, welding using a brazing material 58 is performed. When the lid 56 is made of metal, the brazing material 58 may be a low melting point metal, and when the lid 56 is glass, the brazing material 58 may be low melting point glass.

  In the manufacture of the vibrator 50 according to this embodiment composed of such constituent members, first, the resonator element 10 is mounted inside the package base 54. The vibration piece 10 may be mounted using the adhesive 64. After mounting the resonator element 10 on the package base 54, wire bonding is performed using a gold wire 66 or the like to electrically connect the resonator element mounting terminal 60 and the input / output terminals 42 and 44 (see FIG. 1) of the resonator element 10. Connecting. After the mounting of the resonator element 10 is thus completed, the lid 56 is joined to the package base 54, and the opening is sealed.

  According to the vibrator 50 having such a configuration, the parasitic vibration mode in the resonator element 10 can be suppressed, and high performance and high reliability can be obtained. In the vibrator 50 according to this embodiment, the package base 54 is box-shaped and the lid 56 is flat. However, the package base may be flat and the lid may be cap-shaped.

  Next, an embodiment according to the oscillator of the present invention will be described with reference to FIG. The oscillator 70 according to the present embodiment is basically configured of a resonator element, an electronic component 82 for causing the resonator element to oscillate, and a package 72 in which the resonator element and the electronic component 82 are mounted.

  As the resonator element, the resonator element according to the first to third embodiments (in this embodiment, the resonator element 10, 110, 210 is representatively referred to as the resonator element 10) is employed. The package 72 is configured based on a package base 74 and a lid 76. The package base 74 according to the present embodiment includes a center substrate 74a for mounting as a base point and includes cavities on the upper and lower sides thereof. The upper cavity is a resonator element mounting region 75a and the lower cavity is an electronic component mounting region 75b.

  A vibration piece mounting terminal 60 is provided on the center board 74 on the vibration piece mounting region 75a side, and an electronic component mounting terminal 80 is provided on the electronic component mounting region 75b side. In addition, an external mounting terminal 86 that is electrically connected to the electronic component mounting terminal 80 is provided at a portion corresponding to the bottom surface of the package base 74. The constituent members and the manufacturing method are the same as those of the package base 54 in the vibrator 50 described above. In the present embodiment, the lid 76 may be a flat plate made of metal or glass, and the vibration piece mounting region 75 in the package base 74 is sealed using the brazing material 78.

The electronic component 82 may be an IC provided with an integrated circuit, for example, and may be mounted on the electronic component mounting terminal 80 by flip chip bonding using bumps 84 or the like.
Similarly to the vibrator 50, the oscillator 70 having such a configuration can suppress the parasitic vibration mode in the resonator element 10 and obtain high performance and high reliability.

  As an example of the electronic apparatus according to the present invention, a mobile phone 100 shown in FIG. 11, a personal computer 200 shown in FIG. In any case, at least one of the vibrator 50 and the oscillator 70 shown in the above embodiment is mounted as a local oscillator used for clock source or signal modulation or demodulation. By having such a feature, it is possible to cope with downsizing and thinning of electronic devices. Further, even when downsizing is performed, it is possible to improve the accuracy of communication or the like according to the function of the electronic device.

DESCRIPTION OF SYMBOLS 10 ......... Vibration piece, 12 ...... Substrate, 14 ......... Base part, 16 (16a-16c) ......... Vibrating arm, 20 ......... First electrode, 22 (22a-22c) ......... First Layer excitation electrode, 24 ......... first layer extraction electrode, 26 ......... first layer extraction electrode, 28 ......... piezoelectric layer, 30 (30a-30c) ......... excitation electrode covering portion, 32 ......... Extraction electrode covering portion 34... Opening portion 36... Opening portion 38... Second electrode 40 (40 a to 40 b) ... Second layer excitation electrode 42 42 Input / output electrode 44... I / O electrode 46... Second layer extraction electrode 48... Second layer extraction electrode 50.

Claims (6)

The base,
A vibrating arm extending from the base portion as a base end;
At least a first electrode, a second electrode to which a voltage different in potential from the first electrode is applied, and a piezoelectric layer provided between the first electrode and the second electrode; A laminate including
A bending vibration piece, wherein a widening portion is provided at the base end of the vibrating arm, and a light shielding film is provided on a side surface of the widening portion. The bending vibration piece according to claim 1,
A bending vibration piece characterized in that the light shielding film is constituted by the first electrode. The bending vibration piece according to claim 1,
The bending vibration piece, wherein the light shielding film is an electrically floating metal film. The bending vibration piece according to any one of claims 1 to 3,
And a package for mounting the resonator element therein. The bending vibration piece according to any one of claims 1 to 3,
An oscillation circuit for controlling the oscillation of the bending vibration piece;
An oscillator comprising:   An electronic apparatus comprising the bending vibration piece according to claim 1.

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