JP2008098909A - Piezoelectric vibration piece and piezoelectric device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric vibration piece which can prevent that a CI value rises in such a way that the frequency of a spurious Z common mode rises and approaches the frequency of bending vibration which is principal vibration, and to provide a piezoelectric device using this. <P>SOLUTION: The piezoelectric vibration piece has: a base 51 formed of piezoelectric material; two or more vibration arms 35 and 36 extended from the base; and a pair of support arms 61 and 62 which have both-width direction extension sections extended from the base sections to the both-width directions and which are extended in the same direction as these vibration arms in the both exterior sides of the vibration arms from the width extension section considered as a base end. Each support arm is constituted so as to be joined to a package via conductive adhesives, and metal films 11, 11 for weights are formed in the surface of a region in the vicinity of the base of the respective arms for support. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an improvement of a piezoelectric vibrating piece and a piezoelectric device in which the piezoelectric vibrating piece is housed in a package.

  Packages such as small information devices such as HDDs (hard disk drives), mobile computers, IC cards, mobile communication devices such as mobile phones, car phones, and paging systems, and measuring devices such as gyro sensors Piezoelectric devices such as piezoelectric vibrators and piezoelectric oscillators that house a piezoelectric vibrating piece inside are widely used.

  That is, a support arm for bonding and supporting a piezoelectric device having a configuration in which a piezoelectric vibrating piece is housed in a package is provided to improve the bonding strength of the piezoelectric vibrating piece to the package and to prevent adverse effects on vibration performance due to bonding. A piezoelectric vibrating piece provided and a piezoelectric device in which such a piezoelectric vibrating piece is housed in a package have been devised (Patent Document 1).

FIG. 4 is a schematic plan view illustrating the piezoelectric vibrating piece disclosed in Patent Document 1 in a simplified manner.
In the figure, the entire piezoelectric vibrating piece 1 is formed of a piezoelectric material such as quartz.
That is, the piezoelectric vibrating reed 1 includes a base 2, vibrating arms 3 and 4 extending long in parallel from the base 2, and a pair of supporting members extending from the base 2 and positioned outside the vibrating arms 3 and 4. Arms 5 and 6 are provided and, for example, bend and vibrate at a frequency of 32.768 kHz.

Such a piezoelectric vibrating piece 1 is bonded to the inside of a package (not shown) using support arms 5 and 6.
Specifically, the conductive adhesive, particularly the elastic modulus (elastic modulus), at a total of four points including two points indicated by reference numerals 5a and 5b of the support arm 5 and two points indicated by reference numerals 6a and 6b of the support arm 6. ) Is bonded and fixed with a silicon adhesive or the like.
JP 2006-148857 A

  By the way, when a drive voltage is applied to the piezoelectric vibrating reed 1, the vibrating arms 3 and 4 bend and vibrate so as to approach and separate from each other as indicated by an arrow D in FIG. 4 due to the piezoelectric effect. A signal having a desired frequency is output based on the resonance frequency of the bending vibration. As shown in FIG. 5A, the bending vibration has a Q value peak representing mechanical efficiency at the resonance frequency of the bending vibration (for example, 32.768 KHz).

However, when the resonance frequency of spurious (unnecessary vibration) that is not bending vibration is close to the resonance frequency of bending vibration, mode coupling occurs, and the vibration becomes unstable, resulting in an increase in CI value and an error in output frequency.
For example, as shown in FIG. 4F, when one of the vibrating arms swings in the −Z-axis direction, the other vibrating arm has a WALK mode spurious that swings in the + Z-axis direction. In the WALK mode, the Q value peaks at a frequency higher than the resonance frequency of the bending vibration as shown in FIG.
Further, in a tuning fork type vibrating piece having a support arm, there is a spurious called a Z common mode. In the Z common mode, as shown in FIG. 4E, the connecting portion between the support arm 5 and the base portion 2 and the connecting portion between the support arm 6 and the base portion 2 are moved together in the + Z-axis direction and in the −Z-axis direction. It is a spurious that repeats shaking.
The resonance frequency of the WALK mode can be separated from the resonance frequency of the bending vibration by adjusting the width and thickness of the vibrating arm, but at the same time, it is difficult to control the resonance frequency of the Z common mode.

  The present invention provides a piezoelectric vibrating piece that solves the new problem of eliminating the coupling of the Z common mode that occurs when the piezoelectric vibrating piece is supported via a support arm, and a piezoelectric device using the same. With the goal.

  The above object, according to the first invention, has a base portion made of a piezoelectric material, a plurality of vibrating arms extending from the base portion, and a width direction extension portion extending in both width directions from the base portion, A pair of supporting arms extending in the same direction as the vibrating arm on both outer sides of the vibrating arm with the width direction extension as a base end, and each supporting arm via a conductive adhesive This is achieved by a piezoelectric vibrating piece that is configured to be bonded to a package and that has a metal film for weight formed on the surface of a region close to the base of each of the supporting arms.

According to the configuration of the first invention, the vibrating arm that bends and vibrates extends from one end of the base, and separately, the supporting arm extends from the base.
For this reason, when the support arm is bonded to the base of the package or the like by bonding or the like, the stress change generated at the bonded portion due to a change in ambient temperature or a drop impact is caused by the change in the support arm. The vibrating arm is hardly affected at a distance from the joint location to the other end of the base, and further at a predetermined distance from the base.
In addition, vibration leakage from a vibrating arm that bends and vibrates on the contrary is rarely reached because a predetermined distance is reached before reaching the supporting arm across the base.
In addition, since the weight metal film is formed on the surface of the region close to the base of each of the supporting arms, the frequency of the vibration in the Z common mode, which is a spurious mode, is the frequency of the vibration mode in the bending vibration. , And mode coupling can be prevented, thereby preventing an increase in the CI value of the piezoelectric vibrating piece.

  According to a second aspect of the present invention, in the configuration of the first aspect, each of the support arms is joined to the package in the first region and in the second region closer to the distal end of the support arm than the first region. It is characterized by.

According to a third invention, in the configuration of the first or second invention, an excitation electrode is formed on the vibrating arm as a drive electrode, and a pattern of the excitation electrode passes through the base and serves as an extraction electrode. The weight metal film is formed by adding the thickness of the extraction electrode in a part of the region close to the base of each of the support arms. Features.
According to the configuration of the second invention, by forming the metal film for the weight separately from the extraction electrode, the frequency of the vibration in the Z common mode, which is a spurious mode, approaches the frequency of the vibration mode in the bending vibration. Can be prevented.

According to a fourth aspect of the present invention, in the configuration of the third aspect, the excitation electrode and the extraction electrode of the resonating arm are composed of a base layer formed on a piezoelectric material and an electrode layer formed on the surface of the base layer. The weight metal film, which is a portion to which the thickness is added, is formed of a metal layer, further forms the same metal layer as the base layer on the surface of the extraction electrode, and the same as the electrode layer on the surface A metal layer is formed.
According to the configuration of the fourth invention, the metal film for weight can be formed by using the same manufacturing means as the extraction electrode by forming the metal film for weight with the same electrode metal as the extraction electrode.

According to a fifth aspect of the invention, in the configuration of the fourth aspect of the invention, the tip of the vibrating arm is formed with a frequency adjustment portion formed of a base layer and a metal layer corresponding to the electrode layer, similar to the excitation electrode. The weight metal film is formed in the same process as the frequency adjusting unit.
According to the configuration of the fifth invention, since the metal film for the weight can be formed simultaneously with the formation of the metal layer of the frequency adjusting portion, the metal film for the weight can be formed without substantially increasing the manufacturing process. Can be formed.

According to the sixth aspect of the present invention, there is provided a piezoelectric device having a configuration in which a piezoelectric vibrating piece is accommodated in a package and hermetically sealed by a lid, wherein the piezoelectric vibrating piece is formed of a piezoelectric material. And a plurality of vibrating arms extending from the base, and a width direction extending portion extending in both width directions from the base, with the width direction extending portion serving as a base end on both outer sides of the vibrating arm. And a pair of supporting arms extending in the same direction as the vibrating arms, each supporting arm being configured to be joined to the package via a conductive adhesive, and each of the supporting arms This is achieved by a piezoelectric device in which a metal film for weight is formed on the surface of a region close to the base of the arm for use.
According to the configuration of the sixth invention, according to the same principle as the first invention, it is possible to prevent the vibration frequency of the Z common mode that is the spurious mode from approaching the frequency of the flexural vibration. An increase in CI value of the piezoelectric device can be prevented.

1 and 2 show an embodiment of the piezoelectric device of the present invention. FIG. 1 is a schematic plan view thereof, FIG. 2 is an end view taken along line AA of FIG. 1, and FIG. It is a schematic perspective view of the piezoelectric vibrating piece used for a piezoelectric device.
In these drawings, the piezoelectric device 30 shows an example in which a crystal resonator is configured, and this piezoelectric device 30 houses a piezoelectric vibrating piece 32 in a package 57 as a housing container. The package 57 is, for example, a rectangular box that is slightly long in one direction, as can be understood with reference to FIGS. 1 and 2.
The package 57 is formed, for example, by sequentially laminating a plurality of substrates 54, 55, and 56 formed by molding an aluminum oxide ceramic green sheet as an insulating material, and then sintering. The third substrate 56 is formed so as to form a predetermined hole by removing the material inside thereof, thereby forming a predetermined internal space S on the inner side when stacked. This internal space S is a housing space for housing the piezoelectric vibrating piece 32.

  In addition, with respect to the second substrate 55, a rectangular recess 23 is formed by removing the material of the substrate in a region corresponding to the lower portion of the tip of the vibrating arm of the piezoelectric vibrating piece 32 described later. For this reason, the tip of the vibrating arm is prevented from colliding with the inner bottom surface of the package 57 and being damaged when the tip of the vibrating arm swings downward as shown by the arrow in FIG. ing.

  A piezoelectric vibrating piece 32 is mounted inside the package 57 and hermetically sealed with a lid 40. Here, the lid body 40 is formed of a conductive metal, and is suitable to have a thermal expansion coefficient approximate to that of the package 57, and is preferably a Kovar plate body made of an alloy of iron and cobalt. is there. It should be noted that a through-hole is provided in any part of the lid 40 or the package 57 to provide a window such as Kovar glass (borosilicate glass) to form a light transmitting region, and laser light is packaged from the outside. It is also possible to irradiate inside.

  FIG. 2 shows a transparent window 40a formed by integrating a glass material by placing bulk borosilicate glass or the like in a hole formed in the lid 40 in advance and melting it by heating. In the illustrated case, the laser beam LB is transmitted through the window 40a, and the mass of the frequency adjusting unit 12 made of a metal film formed on the tip of the vibrating arm of the piezoelectric vibrating piece 32 described later is evaporated. It shows how the frequency is adjusted by the reduction method.

A through hole 27 for hole sealing is provided at the bottom of the package 57.
As shown in FIG. 2, the through-hole 27 is preferably provided, for example, in the vicinity of the center of the package 57 and at a location away from the recess 23 in order to withstand a predetermined strength.
As shown in FIG. 2, the through hole 27 is a hole that communicates the outside and the inside of the package 57. The through hole 27 includes a first hole 25 and a second hole 26 that has a diameter reduced from the first hole 25. By providing them in an overlapping manner, an outward stepped portion 29 is provided. The through hole for hole sealing does not necessarily have such a double hole structure, and may be, for example, a tapered through hole that gradually increases in diameter toward the outside. Good. That is, after sealing the package with the lid, it is easy to place a bulk metal material such as a sphere on the step portion 29 when sealing the hole. Then, in this mounted state, the metal material is irradiated with a laser beam or the like and heated and melted, so that the through hole 27 is filled with a metal sealing material 28 such as Au-Ge, for example. It can be sealed.

As shown in FIG. 2, two electrode portions 31, 31 are formed at the bottom of the inner surface of the package 57 so as to be exposed to the internal space S of FIG. 2.
The electrode portions 31 extend long along the length method at both ends in the width direction of the package. The electrode portions 31 and 31 can be formed by, for example, nickel plating and gold plating on tungsten metallization, and are formed on the bottom surface of the package 57 by being drawn out of the package or by providing a conductive through hole (not shown). Are connected to the mounting terminals 41 and 41 respectively.

Thus, the electrode parts 31 and 31 are connected to the outside and supply a driving voltage. As shown in FIG. 1 and FIG. Adhesives 43a, 43b, 43c, and 43d are applied, and a support arm for a piezoelectric vibrating reed described later is placed on the conductive adhesives 43a, 43b, 43c, and 43d, and the conductive adhesive is cured. By doing so, they are joined.
In addition, as the conductive adhesives 43a, 43b, 43c, and 43d, a synthetic resin agent as an adhesive component that exhibits bonding strength can be used containing conductive particles such as silver fine particles, Silicone, epoxy or polyimide conductive adhesives can be used.
Or when not using a conductive adhesive, you may make it join using metal bumps, such as a gold bump.

As shown in FIG. 2, the package 57 of the present embodiment is small, and for example, the vertical dimension (D1) is about 2.0 mm and the horizontal dimension (L1) is about 1.2 mm. And the joining margin L2 with respect to the cover body of the package 57 is about 0.2 mm.
Further, a seam ring 58 as a metal brazing material is preformed on the joint surface of the package 57, for example. The width of the seam ring 58 is about 0.2 mm to 0.15 mm. The seam ring 58 may be preformed on the lid 40 side.

In the present embodiment, the piezoelectric vibrating piece 32 is configured as shown in FIG. 1 and FIG. 3 in order to reduce the size and obtain the required performance.
That is, the piezoelectric vibrating piece 32 is made of, for example, quartz, and a piezoelectric material such as lithium tantalate or lithium niobate can be used in addition to the quartz. As shown in FIG. 1, the piezoelectric vibrating piece 32 is divided into two forks from the base 51 and one end (right end in the drawing) toward the right (oblique right in FIG. 3). A pair of vibrating arms 35 and 36 extending in the direction is provided.
Long grooves 33 and 34 extending in the length direction are preferably formed on the front and back of the main surfaces of the vibrating arms 35 and 36, respectively, and excitation electrodes 37 and 38, which are driving electrodes, are provided in the long grooves. ing.
In this embodiment, the tip portions of the resonating arms 35 and 36 are gradually widened in a slightly tapered shape so that the weight is increased to play the role of a weight. Thereby, the bending vibration of the vibrating arm is easily performed.

Further, the piezoelectric vibrating reed 32 has a base 51 at the other end (left end in the figure) separated from the one end where the vibrating arm of the base 51 is formed by a predetermined distance BL (base length + cut portion length) in FIG. 1 extending in the width direction of each of the vibrating arms 35 and 36 at the positions on both outer sides of the vibrating arms 35 and 36 from the front end thereof (in the right direction in FIG. 1). Direction), supporting arms 61 and 62 extending in parallel with the vibrating arms 35 and 36 are provided.
The tuning fork-shaped outer shape of the piezoelectric vibrating piece 32 and the long groove provided in each vibrating arm are formed by wet etching or dry etching a material such as a quartz wafer with a hydrofluoric acid solution or the like, as will be described later. It can be formed precisely.

The excitation electrodes 37 and 38 are formed in the long grooves 33 and 34 and on the side surfaces of the vibrating arms, and the electrodes in the long grooves and the electrodes provided on the side surfaces of each vibrating arm are paired. The excitation electrodes 37 and 38 are routed around the supporting arms 61 and 62 as extraction electrodes 37a and 38a, respectively. As a result, when the piezoelectric device 30 is mounted on a mounting substrate or the like, an external driving voltage is applied from the mounting terminals 41 and 41 to the support arms 61 and 62 of the piezoelectric vibrating piece 32 via the electrode portions 31 and 31. Are transmitted to the extraction electrodes 37a and 38a, and are transmitted to the respective excitation electrodes 37 and 38.
Then, by applying a driving voltage to the excitation electrodes in the long grooves 33 and 34, the electric field efficiency inside the region where the long grooves of the respective vibrating arms are formed can be increased during driving.

Here, the excitation electrodes 37 and 38 are formed by forming an electrode layer with a metal having excellent conductivity on the base metal layer.
In this embodiment, a chromium (Cr) layer is formed as a base metal layer, and a gold (Au) layer is formed as an electrode layer, and the method shown in FIG. The electrode is formed in such a shape.
In this case, each film formation of the base layer and the electrode layer (not shown) is performed by sputtering or vapor deposition, but in the process for forming a large number of piezoelectric vibrating reeds from a quartz wafer or the like, the film is formed by vapor deposition. Is preferred.

Also, as shown in FIG. 3, preferably, the base 51 is partially reduced in width in the width direction of the base 51 at both side edges at a position sufficiently away from the end of the base 51 on the vibrating arm side. The recessed part or the notch | incision part 71,72 formed in this way is provided.
Thereby, when the vibrating arms 35 and 36 are bent and vibrated, it is possible to suppress vibration leakage from leaking to the base 51 side and propagating to the supporting arms 61 and 62, and to reduce the CI value.
When the strength permits, a through hole (not shown) is formed near the center of the base 51, for example, and stress is concentrated near the periphery of the through hole, so that vibration leakage is caused by the supporting arms 61 and 62. Can be suppressed and the CI value can be kept low.

  In FIG. 1, the joint between the support arms 61 and 61 and the package 57 is, for example, the center of gravity with respect to one support arm 61 across a portion corresponding to the center of gravity position G in the length direction of the piezoelectric vibrating piece 32. Select and join two points equidistant from the position. Thereby, mount mounting can be performed easily. It should be noted that the joint between the support arm 61 and the package 57 can be on the tip side of the support arm 61.

(Z common mode)
Here, in the tuning fork type vibration piece having the support arm, there is a spurious called a Z common mode. In the Z common mode, as shown in FIG. 4E, the connecting portion between the supporting arm 5 and the base portion 2 and the connecting portion between the supporting arm 6 and the base portion 2 are shaken in the + Z-axis direction together with the −Z-axis direction. It is a spurious that repeatedly shakes in the direction.
At 25 degrees Celsius, the resonance frequency of the Z common mode has a peak Q value representing mechanical efficiency at a frequency lower than the resonance frequency of the bending vibration, as indicated by B1 in FIG. However, when the temperature is lowered, the peak of the Q value shifts to a higher frequency. For example, B2 in FIG. 5 is the Q value of the Z common mode at −50 degrees Celsius.
In the present embodiment, the vibration node of the Z common mode is located at the distal end side of the support arm from the position of the conductive adhesive 43a (43c) because the Young's modulus of the conductive adhesive 43 is low at room temperature. However, when the temperature is lowered, the Young's modulus of the conductive adhesive 43 is increased, and the conductive adhesives 43a and 43c on the base side of the support arm are difficult to move in the Z-axis direction. As a result, the node of the Z common mode approaches the conductive adhesives 43a and 43c on the base side of the support arm, and the resonance frequency increases. That is, the peak of the Q value shifts to the high frequency side. As a result, mode coupling between the bending vibration mode and the Z common mode occurs, the vibration becomes unstable, and a CI value increases and a frequency error occurs.
When one of the vibrating arms swings in the -Z-axis direction, the other vibrating arm swings in the + Z-axis direction. As a countermeasure against the spurious in the WALK mode, flexural vibration is achieved by adjusting the vibrating arm width, thickness, and weight at the tip of the vibrating piece. However, it is difficult to control the resonance frequency of the Z common mode at the same time. In addition, the resonance frequency of the Z common mode can be lowered by setting the joint between the support arm 61 and the package 57 to the front end side. However, when the temperature becomes low, the peak of the Q value becomes higher. It may shift and be mode coupled with flexural vibration.

As shown in FIG. 3, weight metal films 11, 11 are formed in regions near the bases 51 of the support arms 61, 62 of the piezoelectric vibrating piece 32. In the piezoelectric vibrating piece 32 of FIG. 3, the excitation electrode and its extraction electrode are not shown.
The weight metal films 11 and 11 are preferably formed of the extraction electrodes 37a and 38a described in FIG.
And each extraction electrode is provided by partially forming it thick.
In the present embodiment, by providing the weight metal films 11 and 11, when the piezoelectric vibrating piece 32 is driven, the spurious in the Z common mode with the lower frequency (the spurious of the symbol B in FIG. 5). ) Can be prevented from approaching the flexural vibration which is the main vibration, thereby preventing an increase in the CI value of the piezoelectric vibrating piece.
Further, if the weight metal films 11 and 11 are formed of the same metal material as each extraction electrode, they can be formed by the same film forming means.
Here, in order to form each extraction electrode partially thick, for example, as a normal electrode film, the underlying layer of chromium is 100 angstroms thick, and the gold on it is 500 angstroms in total, which is 600 angstroms in total. For example, it is possible to form a film by adding gold by using a technique such as vapor deposition so as to increase the thickness of, for example, 15000 to 20000 angstrom.

  Further, as described with reference to FIG. 2, the frequency adjustment units 12 and 12 formed of the base layer and the metal layer corresponding to the electrode layer are provided at the tip of the vibrating arm of the piezoelectric vibrating piece 32 in the same manner as the excitation electrodes 37 and 38. Is formed. Then, the weight metal films 11 and 11 can be formed in the same process simultaneously with the frequency adjusting sections 12 and 12. In this way, the weight metal films 11 and 11 can be formed simultaneously with the formation of the metal layers of the frequency adjusting portions 12 and 12, so that the weight can be reduced without substantially increasing the number of manufacturing steps. Metal films 11 can be formed.

(Modified Example)
Instead of the conductive adhesives 43a, 43b, 43c, and 43d having the configuration shown in FIG. 1, the support arm 61 is joined to the package by using one conductive adhesive. Even in such a configuration, it has been found that the peak of the Q value has temperature dependency. This is because the conductive adhesive does not become a node at a high temperature because the joint vibrates in the Z-axis direction, but at a low temperature, the Young's modulus of the conductive adhesive becomes high and the node in the Z common mode approaches the joint. Therefore, by providing the weight metal films 11, 11, when the piezoelectric vibrating piece 32 is driven, the Z common-mode spurious component (the spurious symbol B in FIG. 5) having the lower frequency is the main vibration. It is possible to prevent the vibration from approaching, thereby preventing an increase in the CI value of the piezoelectric vibrating piece.

The present invention is not limited to the above-described embodiment. Each configuration of each embodiment can be appropriately combined or omitted, and can be combined with other configurations not shown.
In addition, the present invention is not limited to the names of crystal resonators, crystal oscillators, crystal filters, SAW devices, gyros, angle sensors, etc. It can be applied to a piezoelectric device using this.

1 is a schematic plan view of a piezoelectric device according to an embodiment of the present invention. FIG. 3 is a schematic cut end view taken along line AA of the piezoelectric device of FIG. 1. FIG. 2 is a schematic perspective view of a piezoelectric vibrating piece used in the piezoelectric device of FIG. 1. The schematic plan view which shows the conventional piezoelectric vibrating piece simplified. The graph which shows the vibration characteristic of the piezoelectric vibrating piece of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 11 ... Metal film for weights, 12, 12 ... Frequency adjustment part, 27 ... Through-hole (sealing hole), 30 ... Piezoelectric device, 32 ... Piezoelectric vibrating piece, 35, 36 ... vibrating arm, 40 ... lid, 51 ... base, 57 ... package, 58 ... seam ring (sealing material), 61, 62 ... supporting arm

Claims (6)

A base formed of piezoelectric material;
A plurality of vibrating arms extending from the base;
A pair of supporting arms that extend in the same direction as the vibrating arm on both outer sides of the vibrating arm with the widthwise extending portion as a base end, Have
Each support arm is configured to be joined to the package via a conductive adhesive,
In addition, a weight metal film is formed on the surface of a region in the vicinity of the base of each of the supporting arms.   2. The piezoelectric device according to claim 1, wherein each of the support arms is bonded to the package in a first region and a second region closer to the distal end of the support arm than the first region. Vibrating piece.   An excitation electrode is formed as an electrode for driving on the vibrating arm, and a pattern of the excitation electrode passes through the base portion and is routed to the support arm as an extraction electrode. 3. The piezoelectric vibrating piece according to claim 1, wherein the weight metal film is formed by adding a thickness of the extraction electrode in a part of a region adjacent to the base.   The excitation electrode and the extraction electrode of the vibrating arm are formed by two metal layers, a base layer formed on a piezoelectric material and an electrode layer formed on the surface of the base layer, and the thickness is added. The metal film for a weight, which is a portion, is formed by further forming the same metal layer as the underlayer on the surface of the extraction electrode, and forming the same metal layer as the electrode layer on the surface. 3. The piezoelectric vibrating piece according to 3.   Similarly to the excitation electrode, a frequency adjustment unit formed of a base layer and a metal layer corresponding to the electrode layer is formed at the tip of the vibrating arm, and the weight metal film is formed at the same time as the frequency adjustment unit. The piezoelectric vibrating piece according to claim 4, wherein the piezoelectric vibrating piece is formed in the same process. A piezoelectric device configured to house a piezoelectric vibrating piece in a package and hermetically seal with a lid,
The piezoelectric vibrating piece is
A base formed of piezoelectric material;
A plurality of vibrating arms extending from the base;
A pair of supporting arms that extend in the same direction as the vibrating arm on both outer sides of the vibrating arm with the widthwise extending portion as a base end, Have
Each support arm is configured to be joined to the package via a conductive adhesive,
Moreover, a weight metal film is formed on the surface of a region close to the base of each of the supporting arms.

Images