JP2013165405A - Piezoelectric vibration piece, piezoelectric vibrator, oscillator, electronic apparatus, and atomic clock - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric vibration piece which enables a film of a cushioning material to be formed at a target position in the piezoelectric vibration piece and absorbs an impact caused when an impact is applied from the exterior and the piezoelectric vibration piece contacts with a package inner surface.SOLUTION: A piezoelectric vibration piece 4 includes: vibration arm parts 10, 11 where excitation electrodes are formed on surfaces; and a base part 12 fixing the base end sides of the vibration arm parts 10, 11. In the piezoelectric vibration piece 4, at least corners 10c, 11c are covered by a cushioning material 22, composed of a photoresist material, at tips of the vibration arm parts 10, 11. At the tips of the vibration arm parts 10, 11, weight metal films for frequency adjustment (a rough adjustment film 21a and a fine adjustment film 21b) are formed at regions that are not covered by the cushioning material 22.

Description

  The present invention relates to a piezoelectric vibrating piece, a piezoelectric vibrator, an oscillator, an electronic device, and a radio timepiece.

  In recent years, a piezoelectric vibrator using a crystal or the like is used as a time source, a timing source of a control signal, a reference signal source, or the like in a mobile phone or a portable information terminal device. Various types of piezoelectric vibrators of this type are provided. The piezoelectric vibrator has a package composed of a base substrate and a lid substrate bonded to each other, and the piezoelectric vibrating piece is stored in a cavity formed between the two substrates. A surface mount device (SMD, Surface Mount Device) piezoelectric vibrator is known.

  In recent years, when the piezoelectric device has been miniaturized and the thickness of the package is reduced, the clearance between the piezoelectric vibrating piece and the base substrate is reduced, so that the tip of the piezoelectric vibrating piece collides with the base substrate when an external impact is applied. The piezoelectric vibrating piece is easily damaged. For this purpose, there is a known technique for preventing a collision by mounting the piezoelectric vibrating piece one step higher than the base substrate, or providing a recess near the tip of the piezoelectric vibrating piece on the base substrate to ensure the clearance between the piezoelectric vibrating piece tip and the base substrate. It has been.

  When the piezoelectric vibrating piece is mounted one step higher than the base substrate, the package thickness increases. Further, when the recess is provided near the tip of the piezoelectric vibrating piece of the base substrate, the manufacturing process of the base substrate becomes complicated, and the manufacturing cost increases while the strength of the substrate itself decreases. Further, when a stronger impact is applied from the outside, there is a possibility that the collision between the tip of the piezoelectric vibrating piece and the base substrate cannot be completely prevented even if the above method is used.

  In view of this, a method has been proposed in which a shock absorbing material is provided on the inner surface of the package or the tip of the piezoelectric vibrating piece to reduce the shock and prevent the piezoelectric vibrating piece from being damaged when an external shock is applied (Patent Document 1). ).

  However, if the cushioning material is not accurately placed at the target position on the inner surface of the package or the tip of the piezoelectric vibrating piece, the buffering function cannot be sufficiently exerted, and the frequency characteristics of the piezoelectric vibrating piece may vary. It was.

JP 2003-60475 A

  The present invention has been made in view of the above-described facts, and when the shock absorbing material is accurately formed at the target position of the piezoelectric vibrating piece and receives an impact from the outside, the tip of the piezoelectric vibrating piece is obtained. It is an object of the present invention to provide a piezoelectric vibrating piece, a piezoelectric vibrator, an oscillator, an electronic device, and a radio timepiece that can absorb an impact when the portion swings and comes into contact with the inner surface of a package.

In order to solve the above problem, the piezoelectric vibrating piece according to claim 1,
A vibrating arm having excitation electrodes formed on the surface;
A base for fixing the base end side of the vibrating arm; and
In a piezoelectric vibrating piece comprising:
At least a corner portion of the tip of the vibrating arm portion is covered with a buffer material made of a photoresist material.

  According to the first aspect of the present invention, since the buffer material made of the photoresist material is provided, the buffer material can be accurately formed at the target position of the piezoelectric vibrating piece using the photolithography technique. Also, since the corner of the tip of the vibrating arm is covered with a cushioning material, when the vibrating arm swings due to an external shock, it absorbs the shock when the tip contacts the outside. Can do.

According to a second aspect of the present invention, in the piezoelectric vibrating piece according to the first aspect,
At the tip of the vibrating arm,
A weight metal film for frequency adjustment is formed in a region not covered with the buffer material.

  According to the second aspect of the present invention, since the weight adjusting weight metal film is exposed without being covered with the buffer material, the desired frequency adjustment of the piezoelectric vibrating piece can be easily performed.

In order to solve the above problem, the piezoelectric vibrator according to claim 3,
A base substrate;
A lid substrate bonded to the base substrate in a state of facing the base substrate;
The piezoelectric vibrating piece of the present invention housed in a cavity formed between the base substrate and the lid substrate;
It is characterized by providing.

  According to the third aspect of the present invention, since the above-described piezoelectric vibrating piece is provided, the size of the piezoelectric vibrating piece is reduced, and when the piezoelectric vibrator receives an impact from the outside, the vibrating arm portion of the piezoelectric vibrating piece is shaken. The impact at the time of moving and colliding with the package wall surface or when the side surfaces of the vibrating arm collide with each other can be alleviated, and damage to the piezoelectric vibrating piece can be prevented. As a result, a piezoelectric vibrator having excellent reliability can be provided.

In order to solve the above-mentioned problem, the transmitter according to claim 4,
The piezoelectric vibrator of the present invention is electrically connected to an integrated circuit as an oscillator,
It is characterized by that.

In order to solve the problem, an electronic device according to claim 5 is provided.
The piezoelectric vibrator of the present invention is electrically connected to the timing unit,
It is characterized by that.

In order to solve the problem, the radio timepiece according to claim 6 is:
The piezoelectric vibrator of the present invention is electrically connected to the filter unit,
It is characterized by that.

  According to the oscillator, the electronic device, and the radio timepiece according to the present invention, since the piezoelectric vibrator described above is provided, it is possible to provide an oscillator, an electronic device, and a radio timepiece that are excellent in reliability.

  According to the piezoelectric vibrating piece according to the present invention, since the buffer material made of a photoresist material is provided, the buffer material can be accurately formed at a target position of the piezoelectric vibrating piece using a photolithography technique. Also, since the corner of the tip of the vibrating arm is covered with a cushioning material, when the vibrating arm swings due to an external shock, it absorbs the shock when the tip contacts the outside. Can do.

1 is an external perspective view of a piezoelectric vibrator according to an embodiment. It is an internal block diagram of the piezoelectric vibrator shown in FIG. FIG. 3 is a cross-sectional view of the piezoelectric vibrator taken along line AA in FIG. 2. FIG. 2 is an exploded perspective view of the piezoelectric vibrator shown in FIG. 1. FIG. 2 is a plan view of a piezoelectric vibrating piece constituting the piezoelectric vibrator shown in FIG. 1. FIG. 6 is a bottom view of the piezoelectric vibrating piece shown in FIG. 5. It is sectional drawing in the BB line of FIG. (A) is a top view of the piezoelectric vibrating piece according to the embodiment, (b) is a side view, and (c) is a front view. It is a flowchart of the manufacturing method of the piezoelectric vibrator shown in FIG. FIG. 3 is an exploded perspective view of a wafer body in which a base substrate wafer and a lid substrate wafer are anodically bonded in a state where a piezoelectric vibrating piece is accommodated in a cavity. (A) is a top view of the piezoelectric vibrating piece which concerns on the 1st modification of embodiment, (b) is a side view, (c) is a front view. (A) is a top view of the piezoelectric vibrating piece according to the second modification of the embodiment, (b) is a side view, and (c) is a front view. It is a schematic block diagram of an oscillator. It is a block diagram of an electronic device. It is a block diagram of a radio timepiece. It is sectional drawing of the piezoelectric vibrator of a comparative example.

Next, the present invention will be described in more detail with reference to the drawings with reference to embodiments and examples. However, the present invention is not limited to these embodiments and examples.
Also, in the description using the following drawings, it should be noted that the drawings are schematic and the ratio of each dimension and the like are different from the actual ones, and are necessary for the description for easy understanding. Illustrations other than the members are omitted as appropriate.

(1) Piezoelectric Vibrator Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a surface mount type piezoelectric vibrator will be described as an example of the piezoelectric vibrator 1.

(1 · 1) Schematic Configuration of Piezoelectric Vibrator As shown in FIGS. 1 to 4, the piezoelectric vibrator 1 of this embodiment is a package in which a base substrate 2 and a lid substrate 3 are anodically bonded via a bonding film 35. 9 and the piezoelectric vibrating reed 4 housed in the cavity C of the package 9.
3 and 4, the illustration of the excitation electrode 15, the extraction electrodes 19 and 20, the mount electrodes 16 and 17, and the weight metal film 21 of the piezoelectric vibrating reed 4 is omitted for easy understanding of the drawings. Similarly, in FIG. 1 to FIG. 7, the cushioning material 22 is omitted for easy understanding of the drawings.

(1-2) Configuration of Piezoelectric Vibrating Piece In the present embodiment, as shown in FIGS. 5 to 8, the piezoelectric vibrating piece 4 is formed of a piezoelectric material such as quartz, lithium tantalate, or lithium niobate, A tuning fork type vibrating piece that vibrates when a predetermined voltage is applied will be described as an example.

The piezoelectric vibrating piece 4 is a piezoelectric plate having a pair of vibrating arm portions 10 and 11 arranged in parallel and a base portion 12 that integrally fixes the base end sides of the pair of vibrating arm portions 10 and 11. Have. Also, an excitation electrode 15 formed on the outer surface of the pair of vibrating arm portions 10 and 11 and including a first excitation electrode 13 and a second excitation electrode 14 that vibrate the pair of vibrating arm portions 10 and 11, and Mount electrodes 16 and 17 are electrically connected to the first excitation electrode 13 and the second excitation electrode 14. A portion where the mount electrodes 16 and 17 are formed on the surface of the base portion 12 is a mount portion.
The piezoelectric vibrating reed 4 is provided with groove portions 18 formed along the longitudinal direction of the vibrating arm portions 10 and 11 on both main surfaces of the pair of vibrating arm portions 10 and 11. The groove portion 18 is formed from the proximal end side of the vibrating arm portions 10 and 11 to the vicinity of the middle.

  The excitation electrode 15 including the first excitation electrode 13 and the second excitation electrode 14 is an electrode that vibrates the pair of vibrating arm portions 10 and 11 at a predetermined resonance frequency in a direction approaching or separating from each other. Patterning is performed on the outer surfaces of the vibrating arm portions 10 and 11 while being electrically separated from each other. Specifically, the first excitation electrode 13 is mainly formed on the groove portion 18 of one vibration arm portion 10 and on both side surfaces of the other vibration arm portion 11, and the second excitation electrode 14 is formed on one side. Are formed mainly on both side surfaces of the vibrating arm portion 10 and on the groove portion 18 of the other vibrating arm portion 11.

  Further, the first excitation electrode 13 and the second excitation electrode 14 are electrically connected to the mount electrodes 16 and 17 via the extraction electrodes 19 and 20, respectively, on both main surfaces of the base portion 12. A voltage is applied to the piezoelectric vibrating reed 4 via the mount electrodes 16 and 17. The excitation electrode 15, the mount electrodes 16 and 17, and the extraction electrodes 19 and 20 described above are made of a conductive film such as chromium (Cr), nickel (Ni), aluminum (Al), or titanium (Ti). It is formed.

Further, a weight metal film 21 for performing mass adjustment (frequency adjustment) so that the pair of vibrating arm portions 10 and 11 vibrate within a predetermined frequency range is provided at the distal ends of the pair of vibrating arm portions 10 and 11. Is coated.
The weight metal film 21 is divided into a coarse adjustment film 21a used when adjusting the frequency roughly and a fine adjustment film 21b used when adjusting the frequency finely. By adjusting the frequency using the coarse adjustment film 21a and the fine adjustment film 21b, the frequency of the pair of vibrating arm portions 10 and 11 can be kept within the range of the nominal (target) frequency of the device.

(1.3) Buffer Material Further, a buffer material 22 is formed on the tip portions of the pair of vibrating arm portions 10 and 11 so as to cover the weight metal film 21. Hereinafter, the buffer material 22 will be specifically described with reference to the drawings.
8A is a plan view of the vibrating arm portions 10 and 11, FIG. 8B is a side view of the vibrating arm portions 10 and 11, and FIG. 8C is an end front view of the vibrating arm portions 10 and 11. It is a P arrow view of Drawing 8 (a) and (b).
In FIG. 8, the longitudinal direction of the vibrating arm portions 10 and 11 is defined as the X direction, the arrangement direction of the pair of vibrating arm portions 10 and 11 is defined as the Y direction, and the thickness direction of the piezoelectric vibrating piece is defined as the Z direction.

  A buffer material 22 is formed in a region surrounded by a one-dot chain line in FIG. In particular, the corners 10c (11c) (see FIG. 8) at the four corners of the tip surfaces of the vibrating arm portions 10 and 11 are covered with the cushioning material 22, so that the vibrating arm portions 10 and 11 are shaken by an external impact. When it moves, it is protected by the buffer material 22. This will be specifically described below.

As shown in FIG. 8, the cushioning material 22 is formed on the entire tip surfaces of the vibrating arm portions 10 and 11 and on both sides of the tip portions. Thereby, the ridge line between the front end surface and the side surface of the vibrating arm portions 10 and 11 is covered with the buffer material 22. Note that the end side of the cushioning material 22 on the base end side of the vibrating arm portions 10 and 11 is disposed further to the front end side than the end side on the front end side of the excitation electrode (not shown).
The buffer material 22 is also formed on both main surfaces of the vibrating arm portions 10 and 11, and the buffer material 22 on both main surfaces has an opening 22a. The width of the opening 22 a is smaller than the width of the vibrating arms 10 and 11, and the center of the opening 22 a in the width direction coincides with the center of the vibrating arms 10 and 11 in the width direction. Accordingly, the ridge line between the main surface and the side surface of the vibrating arm portions 10 and 11 is covered with the cushioning material 22.
On the other hand, the end side of the opening 22a on the distal end side of the vibrating arm portions 10 and 11 is closer to the proximal end side of the vibrating arm portions 10 and 11 than the ridge line between the main surface and the distal end surface of the vibrating arm portions 10 and 11. Has been placed. Thereby, the ridge line between the front end surface and the main surface of the vibrating arm portions 10 and 11 is covered with the cushioning material 22.

As described above, in the present embodiment, the ridge line between the tip surface and the side surface of the vibrating arm portions 10 and 11, the ridge line between the tip surface and the main surface, and the ridge line between the main surface and the side surface are Each is covered with a buffer material 22. As a result, the corners 10 c (11 c) at the four corners of the tip surfaces of the vibrating arm portions 10 and 11 are covered with the cushioning material 22.
Since the ridge line (in particular, the corners at both ends of the ridge line) between the distal end surface and the main surface of the vibrating arm portions 10 and 11 is covered with the cushioning material 22, the vibrating arm portions 10 and 11 are affected by an external impact. Even when the oscillates in the Z direction, the impact caused by the collision with the package wall surface can be reduced. In addition, since the ridge line between the distal end surface and the side surface of the vibrating arm portions 10 and 11 (particularly, the corner portions at both ends of the ridge line) is covered with the cushioning material 22, the vibrating arm portion 10, Even when 11 swings in the Y direction, the impact caused by the collision between the vibrating arms can be reduced.

Further, the end side of the opening 22 a on the base end side of the vibrating arm portions 10, 11 is arranged further on the base end side than the end side of the fine adjustment film 21 b on the base end side of the vibrating arm portions 10, 11. As a result, at least a part of the weight metal films (coarse adjustment film 21a and fine adjustment film 21b) formed on the main surfaces of the vibrating arms 10 and 11 are exposed to the outside from the opening 22a.
Accordingly, the opening 22a shown in FIG. 8A becomes a region for performing mass adjustment (frequency adjustment). That is, using the opening 22a, the coarse adjustment film 21a of the weight metal film 21 is irradiated with laser to evaporate a part thereof and the resonance frequency is coarsely adjusted, and the fine adjustment film 21b is irradiated with laser to resonate. A fine-tuning step (hereinafter, sometimes referred to as laser trimming) for adjusting the frequency with higher accuracy can be performed.

  The buffer material 22 can be formed at an arbitrary position at the tips of the vibrating arm portions 10 and 11 by a photolithography technique (hereinafter referred to as a photolithography technique) using a photosensitive negative resist. As the negative resist, a rubber negative resist mainly composed of cyclized rubber (for example, cyclized isoprene) can be suitably used. The rubber negative resist is refined by dissolving cyclized rubber in an organic solvent, adding a bisazide photosensitizer, filtering, and removing impurities. A rubber-based negative resist is suitable as a buffer material because it retains elasticity even after pre-baking and exposing the pattern of the buffer material using a photomask.

  As shown in FIGS. 3 and 4, the piezoelectric vibrating reed 4 configured in this manner is bump-bonded to the upper surface side of the base substrate 2 using bumps B such as gold. More specifically, bump bonding is performed with a pair of mount electrodes 16 and 17 in contact with two bumps B formed on lead electrodes 36 and 37 (described later) patterned on the upper surface of the base substrate 2. ing. As a result, the piezoelectric vibrating reed 4 is supported in a state of floating from the upper surface of the base substrate 2, and the mount electrodes 16 and 17 and the routing electrodes 36 and 37 are electrically connected to each other.

(1.4) Configuration of Piezoelectric Vibrator As shown in FIGS. 1 to 4, the piezoelectric vibrator 1 of this embodiment includes a package 9 in which a base substrate 2 and a lid substrate 3 are laminated in two layers. ing.
The base substrate 2 is a transparent insulating substrate made of a glass material such as soda lime glass, and is formed in a plate shape.

  As shown in FIGS. 2 and 3, the base substrate 2 is formed with a pair of through holes (through holes) 30 and 31 that penetrate the base substrate 2. The pair of through holes 30 and 31 are formed at both ends of the diagonal line of the cavity C. A pair of through electrodes 32 and 33 are formed so as to fill the pair of through holes 30 and 31. These through electrodes 32 and 33 are made of a conductive material such as Ag paste. On the lower surface of the base substrate 2, a pair of external electrodes 38 and 39 that are electrically connected to the pair of through electrodes 32 and 33, respectively, are formed.

  As shown in FIGS. 2 to 4, on the upper surface side of the base substrate 2 (the bonding surface side to which the lid substrate 3 is bonded), a pair of lead-out electrodes 36 and 37 are patterned with a conductive material (for example, aluminum). ing. The pair of lead electrodes 36 and 37 electrically connect one of the pair of through electrodes 32 and 33 to the one mount electrode 16 of the piezoelectric vibrating reed 4 and the other through electrode 33. The piezoelectric vibrating piece 4 is patterned so as to be electrically connected to the other mount electrode 17.

As shown in FIGS. 1, 3 and 4, the lid substrate 3 is a transparent insulating substrate made of a glass material, for example, soda lime glass, like the base substrate 2, and as shown in FIGS. It is formed in a plate shape with a size that can be superimposed on the base substrate 2. A rectangular recess 3 a in which the piezoelectric vibrating reed 4 is accommodated is formed on the bonding surface side to which the base substrate 2 is bonded. The recess 3 a is a cavity recess that serves as a cavity C that accommodates the piezoelectric vibrating reed 4 when the substrates 2 and 3 are overlapped. Note that the bottom surface of the recess 3a in the lid substrate 3 is a non-polished surface (abraded glass).
The lid substrate 3 is anodically bonded to the base substrate 2 with the recess 3a facing the base substrate 2 side.

As shown in FIGS. 1 to 4, the piezoelectric vibrator 1 of the present embodiment is formed over the entire surface of the lid substrate 3 facing the base substrate 2 side, and the two substrates 2 and 2 are in contact with the base substrate 2. 3 is provided. As shown in FIG. 2 and FIG. 3, the bonding film 35 of the present embodiment includes a surface that defines the recess 3 a and a peripheral portion that is continuous with the outer periphery of the recess 3 a on the bonding surface of the lid substrate 3. It is formed over the entire area. Of these, the bonding film 35 formed on the peripheral edge of the bonding surface is bonded to the base substrate 2.
The bonding film 35 is formed of a material capable of anodic bonding the substrates 2 and 3. As the material of the bonding film 35, for example, aluminum can be used.

  In order to operate the piezoelectric vibrator 1 configured as described above, a predetermined drive voltage is applied to the external electrodes 38 and 39 formed on the base substrate 2. As a result, a voltage can be applied to the excitation electrode 15 including the first excitation electrode 13 and the second excitation electrode 14 of the piezoelectric vibrating reed 4, and the pair of vibrating arm portions 10 and 11 can be moved closer to and away from each other. It can be vibrated at a predetermined frequency. The vibration of the pair of vibrating arm portions 10 and 11 can be used as a time source, a control signal timing source, a reference signal source, and the like.

(2) Manufacturing Method of Piezoelectric Vibrator Next, a manufacturing method of the piezoelectric vibrator 1 described above will be described with reference to a flowchart.
FIG. 9 is a flowchart of the manufacturing method of the piezoelectric vibrator 1 of the present embodiment.
FIG. 10 is an exploded perspective view of the wafer body. In addition, the dotted line shown in FIG. 10 has shown the cutting line M cut | disconnected by the cutting process performed later.
The method for manufacturing the piezoelectric vibrator 1 according to the present embodiment mainly includes a piezoelectric vibrating piece manufacturing step (S10), a lid substrate wafer manufacturing step (S20), a base substrate wafer manufacturing step (S30), and an assembly. It has a process (after S40). Among them, the piezoelectric vibrating piece producing step (S10), the lid substrate wafer producing step (S20) and the base substrate wafer producing step (S30) can be performed in parallel.

(2.1) Piezoelectric Vibrating Piece Creating Step In the piezoelectric vibrating piece producing step S10, the piezoelectric vibrating piece 4 shown in FIGS. 5 to 7 is produced. Specifically, first, a crystal Lambert ore is sliced at a predetermined angle to obtain a wafer having a constant thickness. Subsequently, the wafer is lapped and roughly processed, and then the work-affected layer is removed by etching, and then mirror polishing such as polishing is performed to obtain a wafer having a predetermined thickness. Subsequently, after appropriate processing such as cleaning is performed on the wafer, the wafer is patterned into the outer shape of the piezoelectric vibrating reed 4 by photolithography. Subsequently, the metal film is formed and patterned to form the excitation electrode 15, the extraction electrodes 19 and 20, the mount electrodes 16 and 17, and the weight metal film 21.

  Next, a rubber-based negative resist material is applied to the entire surface of both main surfaces of the wafer on which the excitation electrode 15, the extraction electrodes 19 and 20, the mount electrodes 16 and 17, and the weight metal film 21 are formed, thereby forming a photoresist film. . In addition, since the outer shape of the piezoelectric vibrating piece is already formed on the wafer, it is preferable to use spray coating or dip coating for applying the rubber-based negative resist material.

Subsequently, the photoresist film is exposed using a photomask on which the pattern of the buffer material 22 is drawn and developed to form the buffer material 22 that covers the tips of the vibrating arm portions 10 and 11 (S11, FIG. 8). reference). As described above, the cushioning material 22 is formed so as to have the opening 22 a while covering the distal end portions of the vibrating arm portions 10 and 11. Thereby, when the piezoelectric vibrator 1 receives an impact from the outside, the tip ends of the vibrating arm portions 10 and 11 swing in the vertical direction (Z direction) and collide with the package wall surface, or in the horizontal direction (Y direction). It is possible to relieve the impact caused by the swinging of the side surfaces of the vibrating arm portions 10 and 11 and to prevent the piezoelectric vibrating piece from being damaged.
The film thickness of the buffer material 22 needs to be a film thickness that can adjust the frequency of the piezoelectric vibrating piece within the range of the nominal frequency in the coarse adjustment step and that can exhibit a sufficient buffer effect. Become. Since the clearance between the base substrate 2 and the piezoelectric vibrating piece 4 is generally 20 μm to 30 μm, if the buffer material 22 has a film thickness of 2 μm to 3 μm, the frequency of the piezoelectric vibrating piece is a predetermined frequency. It is within the range and can exhibit a sufficient buffering effect.

  Next, the resonance frequency of the piezoelectric vibrating reed 4 is roughly adjusted (S12). The buffer material 22 has an opening 22a for laser trimming patterned. Therefore, in the coarse adjustment process, the opening 22a is used to irradiate the coarse adjustment film 21a of the weight metal film 21 with a laser beam to evaporate a part thereof, thereby changing the weight of the vibrating arm portions 10 and 11. Do. The fine adjustment for adjusting the resonance frequency with higher accuracy is performed after the piezoelectric vibrating reed 4 is mounted. This will be described later.

  Next, a cutting step is performed in which the connecting portion that connects the wafer and the piezoelectric vibrating piece 4 is cut to separate the plurality of piezoelectric vibrating pieces 4 from the wafer into smaller pieces (S13). Thereby, the buffer material 22 is formed on the tip of the vibrating arms 10 and 11 from the wafer, and the piezoelectric vibrating piece in which the electrode films (excitation electrode 15, extraction electrodes 19 and 20 and mount electrodes 16 and 17) are formed. A plurality of 4 can be manufactured at a time.

(2.2) Lid Substrate Wafer Creation Step Next, as shown in FIG. 9, a first wafer production step is performed in which a lid substrate wafer 50 that will later become a lid substrate is produced to a state just before anodic bonding. (S20).
In this step, first, soda-lime glass is polished and washed to a predetermined thickness, and then a disk-shaped lid substrate wafer 50 is formed by removing the outermost work-affected layer by etching or the like (S21). Next, a recess forming step for forming a plurality of cavity recesses 3a in the matrix direction by etching or the like on the bonding surface of the lid substrate wafer 50 is performed (S22). Next, a bonding film forming step is performed in which a material capable of anodic bonding (for example, aluminum) is formed over the entire bonding surface side of the lid substrate wafer 50 (S23). At this point, the first wafer manufacturing process is completed.

(2.3) Base Substrate Wafer Creation Step Next, a second wafer for producing a base substrate wafer 40 to be a base substrate later until the state immediately before anodic bonding is performed at the same time as or before or after the above steps. A production process is performed (S30).
In this step, first, after soda-lime glass is polished and washed to a predetermined thickness, a disk-shaped base substrate wafer 40 is formed by removing the outermost work-affected layer by etching or the like (S31). Next, a through electrode forming step for forming a plurality of pairs of through electrodes 32 and 33 on the base substrate wafer 40 is performed (S32). Next, a lead electrode forming step (S33) is performed in which a conductive material is patterned on the upper surface of the base substrate wafer 40 to form lead electrodes 36 and 37. At this point, the second wafer manufacturing process is completed.

(2.4) Assembly Step Next, a mounting step is performed in which the produced plurality of piezoelectric vibrating reeds 4 are joined to the upper surface of the base substrate wafer 40 via the routing electrodes 36 and 37, respectively (S40). First, bumps B such as gold are formed on the pair of lead-out electrodes 36 and 37, respectively. Then, after the base 12 of the piezoelectric vibrating piece 4 is placed on the bump B, the piezoelectric vibrating piece 4 is pressed against the bump B while heating the bump B to a predetermined temperature. As a result, the piezoelectric vibrating reed 4 is mechanically supported by the bumps B and floats from the upper surface of the base substrate wafer 40, and the mount electrodes 16 and 17 and the routing electrodes 36 and 37 are electrically connected. It becomes a state.

  After the mounting of the piezoelectric vibrating reed 4 is completed, as shown in FIG. 10, a superimposing step of superimposing the lid substrate wafer 50 on the base substrate wafer 40 is performed (S50). Specifically, both wafers 40 and 50 are aligned at the correct position while using a reference mark (not shown) as an index. As a result, the mounted piezoelectric vibrating reed 4 is accommodated in the cavity C formed between the wafers 40 and 50.

  After the superposition process, the superposed two wafers 40 and 50 are put into an anodic bonding apparatus (not shown), and a predetermined voltage is applied in a predetermined temperature atmosphere to perform the anodic bonding (S60). Specifically, a predetermined voltage is applied between the bonding film 35 and the base substrate wafer 40. As a result, an electrochemical reaction occurs at the interface between the bonding film 35 and the lid substrate wafer 50, and the two are firmly bonded and anodically bonded. Thereby, the piezoelectric vibrating reed 4 can be sealed in the cavity C, and the wafer body 60 in which the base substrate wafer 40 and the lid substrate wafer 50 are bonded can be obtained.

  After the anodic bonding described above is completed, a conductive material is patterned on the lower surface of the base substrate wafer 40, and a pair of external electrodes 38, 39 (which are electrically connected to the pair of through electrodes 32, 33, respectively) An external electrode forming step of forming a plurality of the electrodes (see FIG. 3) is performed (S70). By this step, a wafer body 60 is formed in which a plurality of piezoelectric vibrators 1 are connected to each other, and the piezoelectric vibrating reed 4 sealed in the cavity C from the external electrodes 38 and 39 via the through electrodes 32 and 33 is formed. It can be activated.

Next, in the state of the wafer body 60, a fine adjustment step S80 for finely adjusting the frequency of each piezoelectric vibrator sealed in the cavity C to be within a predetermined range is performed.
Specifically, a voltage is applied to a pair of external electrodes 38 and 39 (see FIG. 4) formed on the lower surface of the base substrate wafer 40 to vibrate the piezoelectric vibrating reed 4. Then, laser is irradiated from the outside of the base substrate wafer 40 while measuring the frequency, and the fine adjustment film 21b of the weight metal film 21 is evaporated to perform laser trimming. When the fine-tuning film 21b is trimmed, the weights of the tip portions of the pair of vibrating arm portions 10 and 11 are reduced, and the frequency of the piezoelectric vibrating piece 4 is increased. Thereby, the frequency of the piezoelectric vibrating reed 4 can be finely adjusted so that it falls within a predetermined range of the nominal frequency.
Since the opening 22a for laser trimming is patterned in the buffer material 22, the resonance frequency of the piezoelectric vibrating reed 4 can be finely adjusted using the opening 22a.

After the fine adjustment of the frequency is completed, a cutting step S90 is performed for cutting the bonded wafer body 60 along the cutting line M shown in FIG. Specifically, first, a UV tape is attached to the surface of the base substrate wafer 40 of the wafer body 60. Next, a laser is irradiated along the cutting line M from the lid substrate wafer 50 side (scribing). Next, the cutting blade is pressed along the cutting line M from the surface of the UV tape to cleave the wafer body 60 (braking). Thereafter, the UV tape is peeled off by UV irradiation. The wafer body 60 may be cut by other methods such as dicing.
Thereby, the wafer body 60 can be separated into a plurality of piezoelectric vibrators. That is, the two-layer structure surface mount type piezoelectric vibrator shown in FIG. 1 in which the piezoelectric vibrating reed 4 is sealed in the cavity C formed between the base substrate 2 and the lid substrate 3 which are anodically bonded to each other. Multiple 1s can be manufactured at a time.

  In addition, after performing cutting process S90 and making it into each piezoelectric vibrator, the process order which performs fine adjustment process S80 may be sufficient. However, as described above, by performing the fine adjustment step S80 first, fine adjustment can be performed in the state of the wafer body 60, so that a plurality of piezoelectric vibrators can be finely adjusted more efficiently. Therefore, it is preferable because throughput can be improved.

  Thereafter, the electrical property inspection of the piezoelectric vibrating reed 4 is performed (S100). That is, the resonance frequency, resonance resistance value, drive level characteristic (excitation power dependency of the resonance frequency and resonance resistance value) and the like of the piezoelectric vibrating piece 4 are measured and checked. In addition, the insulation resistance characteristics and the like are also checked. Finally, an appearance inspection of the piezoelectric vibrator 1 is performed to finally check dimensions, quality, and the like. This completes the manufacture of the piezoelectric vibrator 1.

(3) Action and Effect Next, the effect of the piezoelectric vibrating piece of the present embodiment will be described. Prior to that, the problem of the piezoelectric vibrating piece 400 of the comparative example described in Patent Document 1 will be described with reference to the drawings. To do. In addition, in the piezoelectric vibrating piece 400 of the comparative example, the same reference numerals are given to the same components as in the present embodiment, and detailed description thereof is omitted.

(3.1) Piezoelectric vibrating piece of comparative example

  As shown in FIG. 16, the piezoelectric vibrating reed 400 of the comparative example is similar to the piezoelectric vibrating reed 4 according to the present embodiment, in the package 9 in which the base substrate 2 and the lid substrate 3 are anodically bonded via the bonding film 35. Buffer portions 421 and 422 are provided in the upper surface and the lower surface of the free end portion 420 of the resonator element, which are accommodated in the cavity C.

  The buffer portions 421 and 422 are formed by applying a silicon-based adhesive. As a place to apply, it is formed at the front end portion of the free end portion 420 where the amplitude when the vibration piece swings is maximized, and at the substantially central portion in the width direction. In addition, since the silicon-based adhesive having a buffering effect can be applied and formed all at once by, for example, screen printing, the application amount and the application position can be controlled uniformly.

However, it is necessary to precisely control the mass of the buffer portion (the amount of adhesive applied) so as not to affect the piezoelectric vibration of the piezoelectric vibrating piece. In particular, in a tuning fork type piezoelectric vibrating piece, the mass of the tip portion of the free end has a great influence on the piezoelectric vibration of the piezoelectric vibrating piece, so that precise management of the mass of the buffering portion is extremely important.
In the case of a tuning-fork type piezoelectric vibrating piece, the direction of rocking due to external impact is not only in the vertical direction (Z direction) of the vibrating arms but also in the horizontal direction (Y direction) where the vibrating arms are close to each other. There is also. Therefore, it is necessary to accurately form the buffer portion in the vertical direction (Z direction) and the horizontal direction (Y direction) of the tip end portion of the vibrating arm portion.

(3.2) Action / Effect of this Embodiment The piezoelectric vibrating reed 4 according to this embodiment is provided with a cushioning material 22 so as to cover the entire tip surface on the opposite side of the base portion and the entire both side surfaces of the tip portion. The buffer material 22 is patterned by a photolithography technique using a negative resist. Specifically, a rubber-based negative resist material is applied to the entire main surfaces of the piezoelectric vibrating reed 4 on which the excitation electrode 15, the extraction electrodes 19 and 20, the mount electrodes 16 and 17, and the weight metal film 21 are formed. A resist film is formed. Thereafter, exposure is performed using a photomask on which the pattern of the cushioning material 22 formed on the tip portions of the vibrating arm portions 10 and 11 is drawn, and development is performed to cover the corner portions of the tip surfaces of the vibrating arm portions 10 and 11. A resist pattern is formed.

  Since the buffer material 22 is formed of a photoresist material, the buffer material 22 can be formed in a desired film thickness. Moreover, since the buffer material 22 is patterned by the photolithographic technique, the buffer material 22 can be formed in a desired shape. Therefore, it is possible to precisely manage the mass of the buffer material 22, and it is possible to suppress variations in the frequency characteristics of the piezoelectric vibrating reed caused by the buffer material 22. In particular, in the tuning fork type piezoelectric vibrating piece, the mass of the buffer material formed at the tip of the vibrating arm portion can be precisely managed, so that variation in frequency characteristics of the piezoelectric vibrating piece can be prevented.

Further, since the opening 22a for laser trimming can be patterned on the upper surface and the lower surface of the buffer material 22, the opening 22a is used to adjust the desired frequency of the piezoelectric vibrating reed 4 and the piezoelectric vibrator 1. It can be easily implemented.
In addition, since the cushioning material 22 is provided so as to cover the corners of the front end surfaces of the vibrating arm portions 10 and 11, even if the vibrating arm portions 10 and 11 swing in the Z direction due to an external impact, the package The impact caused by the collision with the wall surface can be reduced. Moreover, even when the vibrating arm portions 10 and 11 are swung in the Y direction due to an external impact, the impact caused by the collision between the vibrating arm portions can be reduced.
In particular, since the buffer material 22 is formed of a rubber-based negative resist having elasticity, a high buffer effect can be exhibited.

(4) Modified Example of Piezoelectric Vibrating Piece Next, a modified example of the piezoelectric vibrating piece 4 according to the present embodiment will be described with reference to FIGS. 11 and 12.
In these modified examples, the same components as those in the present embodiment are denoted by the same reference numerals, description thereof is omitted, and only different points will be described.

"First modification"
11A is a plan view of the vibrating arms 10 and 11 of the piezoelectric vibrating piece 200 according to the first modification, FIG. 11B is a side view, and FIG. 11C is an end front view (FIG. 11 ( (a), (b) P arrow view). The first modification is different from the above embodiment in that the base end side of the opening 22a extends to the base end side of the cushioning material 22. Note that detailed description of portions having the same configuration as in the above embodiment is omitted.

  Also in the first modified example, as in the above embodiment, the ridge line between the tip surface and the side surface of the vibrating arm portions 10 and 11, the ridge line between the tip surface and the main surface, and the space between the main surface and the side surface. Are respectively covered with the buffer material 22. Thereby, the corners at the four corners of the tip surfaces of the vibrating arm portions 10 and 11 are covered with the cushioning material 22. Therefore, even when the vibrating arms 10 and 11 are swung in the Z direction due to an external impact, the impact due to the collision with the package wall surface can be reduced. Moreover, even when the vibrating arm portions 10 and 11 are swung in the Y direction due to an external impact, the impact caused by the collision between the vibrating arm portions can be reduced.

  In addition, in the first modification, the base end side of the opening 22 a extends to the base end side of the cushioning material 22. Thereby, the exposure amount of the fine adjustment film 21b is larger than the exposure amount of the coarse adjustment film 21a. Therefore, it is possible to perform laser trimming of the fine adjustment film 21b over a wide range using the opening 22a, and the fine adjustment process can be performed more effectively.

"Second modification"
12A is a plan view of the vibrating arm portions 10 and 11 of the piezoelectric vibrating piece 300 according to the second modification, FIG. 12B is a side view, and FIG. 12C is an end front view (FIG. 12 ( (a), (b) P arrow view). In the second modification, the opening 22a extends to the tip side of the cushioning material 22 and the opening 22a is also formed on the tip surfaces of the vibrating arm portions 10 and 11 so as to connect the openings 22a on both main surfaces. It is different from the above embodiment in that it is formed. Note that detailed description of portions having the same configuration as in the above embodiment is omitted.

  In the second modified example, the ridge line between the tip surface and the side surface of the vibrating arm portions 10 and 11 and the ridge line between the main surface and the side surface are covered with the cushioning material 22, respectively. The central part of the ridge line between the two is not covered with the cushioning material 22. However, both end portions of the ridge line between the tip surface and the main surface are covered with the cushioning material 22. Thereby, the corner | angular part of the four corners in the front end surface of the vibrating arm parts 10 and 11 is covered with the buffer material 22 similarly to the said embodiment. Therefore, even when the vibrating arms 10 and 11 are swung in the Z direction due to an external impact, the impact due to the collision with the package wall surface can be reduced. Moreover, even when the vibrating arm portions 10 and 11 are swung in the Y direction due to an external impact, the impact caused by the collision between the vibrating arm portions can be reduced.

  In addition to this, in the second modification, the distal end side of the opening 22 a extends to the distal end side of the cushioning material 22, and the opening 22 a is also formed on the distal end surfaces of the vibrating arm portions 10 and 11. Thereby, the exposure amount of the rough adjustment film 21a is larger than the exposure amount of the fine adjustment film 21b. Therefore, it is possible to perform laser trimming of the rough adjustment film 21a over a wide range using the opening 22a, and the rough adjustment step can be performed more effectively.

(5) Embodiment of Transmitter Next, an embodiment of an oscillator according to the present invention will be described with reference to FIG.
As shown in FIG. 13, the oscillator 100 according to the present embodiment is configured such that the piezoelectric vibrator 1 is an oscillator electrically connected to the integrated circuit 101. The oscillator 100 includes a substrate 103 on which an electronic component 102 such as a capacitor is mounted. On the substrate 103, the integrated circuit 101 for the oscillator is mounted, and the piezoelectric vibrator 1 is mounted in the vicinity of the integrated circuit 101. The electronic component 102, the integrated circuit 101, and the piezoelectric vibrator 1 are electrically connected by a wiring pattern (not shown). Each component is molded with a resin (not shown).

In the oscillator 100 configured as described above, when a voltage is applied to the piezoelectric vibrator 1, the piezoelectric vibrating piece 4 in the piezoelectric vibrator 1 vibrates. This vibration is converted into an electric signal by the piezoelectric characteristics of the piezoelectric vibrating piece 4 and input to the integrated circuit 101 as an electric signal. The input electrical signal is subjected to various processes by the integrated circuit 101 and is output as a frequency signal. Thereby, the piezoelectric vibrator 1 functions as an oscillator.
Further, by selectively setting the configuration of the integrated circuit 101, for example, an RTC (real-time clock) module or the like according to a request, the operation date and time of the device and the external device in addition to a single-function oscillator for a clock, etc. A function for controlling the time, providing a time, a calendar, and the like can be added.

  As described above, according to the oscillator 100 of the present embodiment, since the piezoelectric vibrator having excellent reliability as in the above-described embodiment is provided, a transmitter having excellent reliability can be provided.

(6) Embodiment of Electronic Device Next, an embodiment of an electronic device according to the present invention will be described with reference to FIG. Note that a portable information device 110 having the above-described piezoelectric vibrator 1 will be described as an example of the electronic device. The portable information device 110 of the present embodiment is represented by, for example, a mobile phone, and is a development and improvement of a wrist watch in the prior art. The appearance is similar to that of a wristwatch, and a liquid crystal display is arranged in a portion corresponding to a dial so that the current time and the like can be displayed on this screen. Further, when used as a communication device, it is possible to perform communication similar to that of a conventional mobile phone by using a speaker and a microphone that are removed from the wrist and incorporated in the inner portion of the band. However, it is much smaller and lighter than conventional mobile phones.

  Next, the configuration of the portable information device 110 of this embodiment will be described. As shown in FIG. 14, the portable information device 110 includes the piezoelectric vibrator 1 and a power supply unit 111 for supplying power. The power supply unit 111 is made of, for example, a lithium secondary battery. The power supply unit 111 includes a control unit 112 that performs various controls, a clock unit 113 that counts time, a communication unit 114 that communicates with the outside, a display unit 115 that displays various types of information, A voltage detection unit 116 that detects the voltage of the functional unit is connected in parallel. The power unit 111 supplies power to each functional unit.

  The control unit 112 controls each function unit to control operation of the entire system such as transmission and reception of audio data, measurement and display of the current time, and the like. The control unit 112 includes a ROM in which a program is written in advance, a CPU that reads and executes the program written in the ROM, and a RAM that is used as a work area of the CPU.

  The timer unit 113 includes an integrated circuit including an oscillation circuit, a register circuit, a counter circuit, an interface circuit, and the like, and the piezoelectric vibrator 1. When a voltage is applied to the piezoelectric vibrator 1, the piezoelectric vibrating reed 4 vibrates, and the vibration is converted into an electric signal by the piezoelectric characteristics of the crystal and is input to the oscillation circuit as an electric signal. The output of the oscillation circuit is binarized and counted by a register circuit and a counter circuit. Then, signals are transmitted to and received from the control unit 112 via the interface circuit, and the current time, current date, calendar information, or the like is displayed on the display unit 115.

The communication unit 114 has functions similar to those of a conventional mobile phone, and includes a radio unit 117, a voice processing unit 118, a switching unit 119, an amplification unit 120, a voice input / output unit 121, a telephone number input unit 122, and a ring tone generation unit. 123 and a call control memory unit 124.
The wireless unit 117 exchanges various data such as audio data with the base station via the antenna 125. The audio processing unit 118 encodes and decodes the audio signal input from the radio unit 117 or the amplification unit 120. The amplifying unit 120 amplifies the signal input from the audio processing unit 118 or the audio input / output unit 121 to a predetermined level. The voice input / output unit 121 includes a speaker, a microphone, and the like, and amplifies a ringtone and a received voice or collects a voice.

Also, the ring tone generator 123 generates a ring tone in response to a call from the base station. The switching unit 119 switches the amplifying unit 120 connected to the voice processing unit 118 to the ringing tone generating unit 123 only when an incoming call is received, so that the ringing tone generated in the ringing tone generating unit 123 is transmitted via the amplifying unit 120. To the audio input / output unit 121.
The call control memory unit 124 stores a program related to communication incoming / outgoing call control. The telephone number input unit 122 includes, for example, number keys from 0 to 9 and other keys, and the telephone number of the call destination is input by pressing these number keys.

  When the voltage applied to each functional unit such as the control unit 112 by the power supply unit 111 falls below a predetermined value, the voltage detection unit 116 detects the voltage drop and notifies the control unit 112 of the voltage drop. . The predetermined voltage value at this time is a value set in advance as a minimum voltage necessary for stably operating the communication unit 114, and is, for example, about 3V. Upon receiving the voltage drop notification from the voltage detection unit 116, the control unit 112 prohibits the operations of the radio unit 117, the voice processing unit 118, the switching unit 119, and the ring tone generation unit 123. In particular, it is essential to stop the operation of the wireless unit 117 with high power consumption. Further, the display unit 115 displays that the communication unit 114 has become unusable due to insufficient battery power.

That is, the operation of the communication unit 114 can be prohibited by the voltage detection unit 116 and the control unit 112, and that effect can be displayed on the display unit 115. This display may be a text message, but as a more intuitive display, a x (X) mark may be attached to the telephone icon displayed at the top of the display surface of the display unit 115.
In addition, the function of the communication part 114 can be stopped more reliably by providing the power supply cutoff part 126 that can selectively cut off the power of the part related to the function of the communication part 114.

  As described above, according to the portable information device 110 of this embodiment, since the piezoelectric vibrator having excellent reliability as in the above embodiment is provided, a transmitter having excellent reliability can be provided. .

(7) Embodiment of Radio Timepiece Next, an embodiment of the radio timepiece according to the present invention will be described with reference to FIG.
As shown in FIG. 15, the radio timepiece 130 of this embodiment includes the piezoelectric vibrator 1 electrically connected to the filter unit 131, and receives a standard radio wave including timepiece information to accurately It is a clock with a function of automatically correcting and displaying the correct time.
In Japan, there are transmitting stations (transmitting stations) that transmit standard radio waves in Fukushima Prefecture (40 kHz) and Saga Prefecture (60 kHz), each transmitting standard radio waves. Long waves such as 40 kHz or 60 kHz have the property of propagating the surface of the earth and the property of propagating while reflecting the ionosphere and the surface of the earth, so the propagation range is wide, and the above two transmitting stations cover all of Japan. doing.

Hereinafter, the functional configuration of the radio timepiece 130 will be described in detail.
The antenna 132 receives a long standard wave of 40 kHz or 60 kHz. The long-wave standard radio wave is obtained by subjecting time information called a time code to AM modulation on a 40 kHz or 60 kHz carrier wave. The received long standard wave is amplified by the amplifier 133 and filtered and tuned by the filter unit 131 having the plurality of piezoelectric vibrators 1.
The piezoelectric vibrator 1 according to this embodiment includes crystal vibrator portions (piezoelectric vibrating pieces) 138 and 139 having resonance frequencies of 40 kHz and 60 kHz that are the same as the carrier frequency.

Further, the filtered signal having a predetermined frequency is detected and demodulated by the detection and rectification circuit 134.
Subsequently, the time code is taken out via the waveform shaping circuit 135 and counted by the CPU 136. The CPU 136 reads information such as the current year, accumulated date, day of the week, and time. The read information is reflected in the RTC 137, and accurate time information is displayed.
Since the carrier wave is 40 kHz or 60 kHz, the crystal vibrator units 138 and 139 are preferably vibrators having the tuning fork type structure described above.

  In addition, although the above-mentioned description was shown in the example in Japan, the frequency of the long standard wave is different overseas. For example, in Germany, a standard radio wave of 77.5 KHz is used. Accordingly, when the radio timepiece 130 that can be used overseas is incorporated in a portable device, the piezoelectric vibrator 1 having a frequency different from that in Japan is required.

  As described above, according to the radio-controlled timepiece 130 of the present embodiment, since the piezoelectric vibrator having excellent reliability as in the above-described embodiment is provided, a highly reliable transmitter can be provided.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above embodiment, as an example of the piezoelectric vibrating piece 4, the tuning fork type piezoelectric vibrating piece 4 having the pair of vibrating arm portions 10 and 11 arranged in parallel has been described as an example. An AT-cut type piezoelectric vibrating piece formed of quartz may be used.

  Moreover, in the said embodiment, although the base substrate 2 and the lid substrate 3 were formed with the glass material, it is not limited to a glass material, You may form with a ceramics and other materials.

In the above embodiment, the base substrate 2 and the lid substrate 3 are anodically bonded via the bonding film 35, but the present invention is not limited to anodic bonding. However, anodic bonding is preferable because both substrates 2 and 3 can be firmly bonded.
In the above embodiment, the piezoelectric vibrating reed 4 is bump-bonded. However, the present invention is not limited to bump bonding. For example, the piezoelectric vibrating reed 4 may be joined with a conductive adhesive. However, by bonding the bumps, the piezoelectric vibrating reed 4 can be lifted from the upper surface of the base substrate 2, and a minimum vibration gap necessary for vibration can be secured naturally. Therefore, it is preferable to perform bump bonding.

  In addition, it is possible to appropriately replace the constituent elements in the embodiment with known constituent elements without departing from the spirit of the present invention, and the above-described modified examples may be appropriately combined.

C Cavity 1 Piezoelectric vibrator 2 Base substrate 3 Lid substrate 4, 200, 300 Piezoelectric vibrating piece 400 Piezoelectric vibrating piece (comparative example)
10c, 11c Corner portion 21 Weight metal film 21a Rough adjustment film 21b Fine adjustment film 22 Buffer material 22a Opening portion 35 Bonding film 40 Base substrate wafer (base substrate)
50 Lid substrate wafer (lid substrate)
DESCRIPTION OF SYMBOLS 100 Oscillator 101 Oscillator integrated circuit 110 Portable information device (electronic device)
113 Timekeeping Unit of Electronic Device 130 Radio Clock 131 Radio Wave Clock Filter

Claims (6)

A vibrating arm having excitation electrodes formed on the surface;
A base for fixing the base end side of the vibrating arm; and
In a piezoelectric vibrating piece comprising:
The piezoelectric vibrating piece according to claim 1, wherein at least a corner portion of the vibrating arm portion is covered with a buffer material made of a photoresist material. At the tip of the vibrating arm,
2. The piezoelectric vibrating piece according to claim 1, wherein a weight adjusting metal film for frequency adjustment is formed in a region not covered with the buffer material. A base substrate;
A lid substrate bonded to the base substrate in a state of facing the base substrate;
The piezoelectric vibrating piece according to claim 1 or 2, wherein the piezoelectric vibrating piece is housed in a cavity formed between the base substrate and the lid substrate.
A piezoelectric vibrator comprising: The piezoelectric vibrator according to claim 3 is electrically connected to an integrated circuit as an oscillator.
An oscillator characterized by that. The piezoelectric vibrator according to claim 3 is electrically connected to the timekeeping unit.
An electronic device characterized by that. The piezoelectric vibrator according to claim 3 is electrically connected to the filter unit.
A radio-controlled timepiece.

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