JP2011171902A - Method of manufacturing piezoelectric vibrator, and piezoelectric vibrator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a piezoelectric vibrator which performs frequency adjustment easily and precisely during manufacture, and can obtain a stabilized oscillation frequency by preventing frequency variations and fluctuations even after manufacturing the piezoelectric vibrator. <P>SOLUTION: The method of manufacturing a piezoelectric vibrator where the oscillation frequency F is adjusted to a predetermined target frequency f0 by providing a frequency adjustment region in vibration arms 23 and 24 having excitation electrodes 29 and 30 formed therein includes a rough adjustment step A for adjusting the oscillation frequency F roughly by irradiating a first metal film 31 with a laser beam after it is formed in the frequency adjustment region, and a fine adjustment step B for adjusting the oscillation frequency F finely toward the target frequency f0 by irradiating a second metal film 33 with an ion beam after it is formed on the surface of the first metal film 31 subjected to rough adjustment. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a piezoelectric vibrator having an oscillation frequency adjustment step and a piezoelectric vibrator.

  A tuning fork type piezoelectric vibrator, which is one of the piezoelectric vibrators, has a base portion and a pair of vibrating arm portions extending from the base portion, and an excitation electrode is formed on the surface of the vibrating arm portion to thereby obtain a predetermined frequency. It oscillates with.

  In such a piezoelectric vibrator, dimensions of each part, excitation electrode patterns, and the like are set at the time of design so that a target oscillation frequency can be obtained. However, even if it is manufactured based on such design values, the oscillation frequency may be adjusted at the final stage of manufacture because it may deviate from the target value depending on the manufacturing conditions and the surrounding environment.

  Adjustment of the oscillation frequency in the tuning fork type piezoelectric vibrator is performed by changing the weight of the tip of the vibrating arm (Patent Documents 1 and 2). As such an adjustment method, a metal film is deposited on the tip of the vibrating arm to adjust it in the direction of decreasing the frequency while gradually increasing the thickness, and the tip of the vibrating arm is adjusted to a laser beam, an ion beam, etc. There is a method of adjusting in the direction of increasing the frequency while lightening by shaving. Particularly in a small tuning fork type piezoelectric vibrator, an adjustment method using a laser beam is widely used because it is easy to obtain the accuracy of the adjustment position.

JP 2003-328771 A JP 2003-332872 A

  The adjustment by the laser beam has an advantage that a large amount of adjustment of the frequency can be obtained because the light energy is concentrated in a narrow range such as φ5 to 30 μm and the metal of the irradiated portion is instantaneously evaporated. On the other hand, metal that could not evaporate easily remains in the vicinity of the laser beam irradiation, and the metal particles may be removed due to impacts, secular changes, or the like, thereby causing frequency fluctuations.

  In addition, the adjustment by the ion beam is a method of adjusting the frequency by changing the mass by irradiating the beam over a wide range (for example, 500 × 500 μm) of the tip of the vibrating arm and gradually reducing the thickness of the metal little by little. is there. Although there is no generation of metal particles like a laser beam, since it is a soft beam, the frequency adjustment rate cannot be increased, and it takes time to adjust the frequency in a wide range, which is not suitable for mass production.

  Usually, the frequency variation of the piezoelectric piece before adjustment occurs due to a dimensional deviation in the shape processing of the piezoelectric piece. As the piezoelectric piece is reduced in size, the relative dimensional deviation width increases, resulting in a large frequency variation. Since the frequency adjustment amount tends to increase as the size becomes smaller, the initial frequency adjustment is often performed by laser beam irradiation. However, as described above, the oscillation frequency may fluctuate after adjustment. .

  On the other hand, according to the ion beam, since the frequency can be finely adjusted, it may be used at the final stage of the adjustment, but it is not suitable for a wide range of frequency adjustment. Therefore, there is a case where a coarse adjustment is performed with a laser beam and then a fine adjustment is performed with an ion beam. However, since this ion beam is processed to make the metal part of the entire tip of the vibrating arm thinner, when adjusting the ion beam after adjusting the laser beam, the metal area of the part where the ion beam is adjusted by the laser mark Differ individually. For this reason, there has been a problem that the frequency adjustment rate at the time of adjustment is not stable, and as a result, the frequency adjustment accuracy deteriorates.

  Accordingly, an object of the present invention is to provide a method of manufacturing a piezoelectric vibrator capable of easily and accurately adjusting a frequency at the time of manufacture, and capable of obtaining a stable oscillation frequency by preventing frequency fluctuation and variation even after the manufacture. The object is to provide a piezoelectric vibrator.

  In order to solve the above-described problems, the piezoelectric vibrator manufacturing method according to the present invention provides a frequency adjustment region in the piezoelectric vibrating portion on which the excitation electrode is formed, so that the oscillation frequency of the piezoelectric vibrating portion is set to a predetermined target frequency. In the method for manufacturing a piezoelectric vibrator to be adjusted, after the first metal film is formed in the frequency adjustment region, a rough adjustment step of coarsely adjusting the oscillation frequency by irradiating the first metal film with a laser beam; After the second metal film is formed on the surface of the first metal film that has been coarsely adjusted, the second metal film is irradiated with an ion beam to finely adjust the oscillation frequency toward the target frequency. And a fine adjustment step.

  Further, the piezoelectric vibrator of the present invention is a piezoelectric vibrator having a frequency adjustment region in a piezoelectric vibration part in which an excitation electrode is formed. The frequency adjustment region has a laser beam mark for adjusting mass. A first metal film, a second metal film formed on a surface of the first metal film, covering the laser beam trace, and having a thickness adjusted to have a predetermined frequency by irradiation with an ion beam; It is characterized by comprising.

  According to the method for manufacturing a piezoelectric vibrator of the present invention, the frequency adjustment region of the piezoelectric vibration unit is shifted to the vicinity of the target frequency in the coarse adjustment step, and further, the fine adjustment step is shifted in the coarse adjustment step. The frequency can be converged to the target value. As described above, the frequency of the piezoelectric vibration unit is determined by the combination of the first metal film and the laser beam irradiated on the first metal film and the ion beam irradiated on the second metal film and the second metal film. Easy adjustment and high-accuracy piezoelectric vibrators can be manufactured.

  Further, according to the piezoelectric vibrator of the present invention, the frequency adjustment region of the piezoelectric vibrating portion is formed by the ion beam on the first metal film in which the laser beam trace is formed and the first metal film including the laser beam trace. The second metal film whose thickness is adjusted can be adapted to a target frequency and can be stably oscillated while maintaining this frequency.

1 is a plan view of a piezoelectric vibrator according to the present invention. It is AA sectional drawing of the said piezoelectric vibrator. FIG. 5 is a cross-sectional view of a main part of a piezoelectric vibrator in which frequency adjustment regions are provided on both front and back surfaces of a vibrating arm part. It is process drawing which shows the manufacturing method of the said piezoelectric vibrator. It is a top view which shows the various forms of a tuning fork type piezoelectric vibrator. It is a top view of a width longitudinal vibration piezoelectric vibrator and a length longitudinal vibration piezoelectric vibrator. It is process drawing which shows the adjustment process of the piezoelectric vibrator of width length length length coupled vibration mode.

  Hereinafter, embodiments of a piezoelectric vibrator and a manufacturing method according to the present invention will be described with reference to the accompanying drawings. The piezoelectric vibrator of the present embodiment is formed by processing a quartz plate cut in a rectangular crystal orthogonal coordinate system in which the electrical axis is the X axis, the mechanical axis is the Y axis, and the optical axis is the Z axis into a tuning fork type. Yes. This piezoelectric vibrator is a crystal piece of XY′Z ′ coordinate system obtained by rotating an XY plane (Z plate) of a three-dimensional orthogonal coordinate system made of XYZ by −7 to +7 degrees by X-axis rotation. The vibration frequency range is set to 32 to 33 kHz. In the piezoelectric vibrator of this embodiment, 32.768 kHz, which is currently widely used as a reference signal for a watch, is set as the target frequency.

  FIG. 1 shows an overall basic shape of the piezoelectric vibrator 21 in the present embodiment, and FIG. 2 shows an AA cross section of the piezoelectric vibrator 21. The piezoelectric vibrator 21 has a rectangular base portion 22 from the crystal piece as a base material, and a pair of piezoelectric vibration portions (vibrating arm portions) 23 and 24 that extend in parallel from the base portion 22 and cause bending vibration. A pair of support arm portions 25 and 26 extending from the base portion 22 are formed along the outer sides of the vibrating arm portions 23 and 24. Excitation electrodes 29 and 30 having different polarities are formed on the outer surfaces of the vibrating arm portions 23 and 24. The excitation electrodes 29 and 30 are continuously formed from the distal end portions of the pair of support arm portions 25 and 26 to the distal end portions of the vibrating arm portions 23 and 24.

  The vibrating arm portions 23 and 24 are a pair of elongated rectangular pillars extending from one end of the base portion 22 in the Y-axis direction and parallel to the X-axis direction, on the front surface side (+ Z surface) and the back surface side (−Z surface). Groove portions 27 and 28 are provided along the respective Y-axis directions. The groove portions 27 and 28 are provided along the + Z plane of the vibrating arm portions 23 and 24 along the longitudinal (Y-axis) direction and the −Z plane along the longitudinal (Y-axis) direction. The groove portions 27 and 28 are formed with substantially the same groove width, groove length, and groove thickness.

  The support arm portions 25 and 26 support the base portion 22 and the vibrating arm portions 23 and 24 in a case (not shown) at the tip portions thereof, and are intended to be electrically connected to a terminal electrode portion provided in the case. Yes. Thus, by extending the support arm portions 25 and 26 long, the impact received by the case is prevented from being directly transmitted to the vibrating arm portions 23 and 24, and the tuning fork vibration generated in the vibrating arm portions 23 and 24 is prevented. Leakage can be prevented.

  In the piezoelectric vibrator 21 having the above-described structure, each tip portion of the pair of vibrating arm portions 23 and 24 is a frequency adjustment region C. As shown in FIG. 2, the frequency adjustment region C is formed on the surface of the excitation electrodes 29 and 30, and a first metal film having a laser processing portion 32 partially evaporated and removed by irradiation with a laser beam. 31 and a second metal film 33 formed on the surface of the first metal film 31 and formed to have a predetermined thickness by irradiation with an ion beam.

  The first metal film 31 is a metal film having a predetermined thickness formed by applying or depositing the same conductive metal material as the excitation electrodes 29 and 30 on the surfaces of the excitation electrodes 29 and 30. The laser processing portion 32 is a laser beam mark removed by part of the surface of the first metal film 31 being evaporated. At the stage where the first metal film 31 is uniformly formed at the tip portions of the vibrating arm portions 23 and 24, the oscillation frequency F is manufactured to be several percent lower than the target frequency f0, and the frequency of each quartz crystal piece is manufactured. By providing the laser beam trace adjusted by the variation, the shift is adjusted to a frequency band slightly higher than the target frequency f0. In addition, the code | symbol 34 is the granular metal scraps which adhered without being able to evaporate with a laser beam.

  The second metal film 33 is formed with a predetermined thickness on the surface of the first metal film 31 including the laser processing portion 32. As the base metal of the second metal film 33, a metal having high adhesive strength with the surface of the crystal piece on which the laser beam mark is formed, for example, chromium, nickel, titanium, or the like is suitable. In order to maintain the function as a base metal, a thickness of about 50 to 500 mm is sufficient. The main metal of the second metal film 33 is a noble metal film such as gold, silver, or platinum that hardly oxidizes for the purpose of preventing the frequency fluctuation of the piezoelectric vibrator 21. The total thickness of the film is a metal In order to firmly fix the trash 34, it is desirable that it is 2000 mm or more. In addition, since the main metal is used as a trimming material when the frequency is adjusted with an ion beam, the thickness becomes smaller than the original thickness after the frequency is adjusted. For this reason, it is necessary to set the thickness to be 1500 mm or more after the frequency adjustment. However, since such a noble metal is expensive and cannot be used frequently, the second metal film 33 may have a base metal of 1000 mm or more, and a noble metal film of about 1000 mm may be formed only on the surface irradiated with the ion beam. Table 1 shows the results of a reliability confirmation test performed by setting the thickness of the second metal film 33 after frequency adjustment to 500 mm, 1000 mm, 1500 mm, and 2000 mm. The items of the reliability confirmation test are a reflow heat resistance test twice and a vibration test when put in the parts feeder for 2 hours.

  In the above embodiment, the frequency adjustment region C composed of the first metal film 31 and the second metal film 33 is formed on the upper surface side of the vibrating arm portions 23 and 24. However, as shown in FIG. A similar frequency adjustment region C ′ can be provided. This frequency adjustment region C ′ is contrasted with the frequency adjustment region C and is given the same reference numeral, but the shape and size of the laser processing part 32 or the first metal film 31 and the second metal film 33 The thickness and the like are appropriately set according to the overall frequency adjustment amount. Thus, by providing the frequency adjustment regions C and C ′ on both the upper and lower surfaces, the frequency adjustment rate can be widened. The frequency adjustment regions C and C ′ need not be contrasted between the upper surface and the lower surface as shown in the figure, but the oscillation frequency is better when the mass balance of the left and right vibrating arm portions 23 and 24 is balanced. Variations and fluctuations can be suppressed.

  Next, the frequency adjusting process after the piezoelectric vibrator 21 is molded will be described with reference to FIG. When the excitation electrodes 29 and 30 are formed on the piezoelectric vibrator 21 formed in a tuning fork shape as shown in FIG. 1, the frequency width f1 is about 300 to 5000 Hz from the target frequency f0 set at the time of design. The oscillation frequency is increased (step a). From this state, an adjustment for bringing the target frequency f0 closer is performed by the coarse adjustment process A and the fine adjustment process B described below.

  In the coarse adjustment step A, first, in order to set the frequency to be lower by about 10 to 2000 Hz than the target frequency f0, the excitation electrode 29 is further provided on the excitation electrodes 29 and 30 at the tip portions of the pair of vibrating arm portions 23 and 24. , 30 is formed to be thicker than the first metal film 31 which is the same conductive member (step b). The thickness of the metal film at this time is about 0.3 to 3 μm when a gold material is used. Then, by irradiating the first metal film 31 with a predetermined amount of laser beam, a laser beam trace in which a part of the laser processing portion 32 is evaporated is generated. The laser beam trace is formed by repeating scanning of the laser beam in the width direction of the vibrating arm portions 23 and 24, and forms a plurality of grooves having a predetermined depth and width. By forming such a laser beam mark, the mass of the tip portions of the vibrating arm portions 23 and 24 is reduced, and the shift adjustment is performed so as to be slightly higher (approximately several tens to several hundreds Hz) than the target frequency f0 (step). c). The frequency variation adjusted by this laser beam irradiation is preferably about several Hz to several tens Hz.

  For example, granular metal debris 34 as shown in FIG. 2 remains on the surface of the first metal film 31 irradiated with the laser beam or in the vicinity thereof. The metal debris 34 also has a mass that defines the oscillation frequency F. Since it is contained, it is coated with the second metal film 33 so as not to drop off (step d). By the coating of the second metal film 33, the oscillation frequency F is shifted and set slightly lower than the target frequency f0 (several Hz to several tens Hz). The coating is performed by sputtering, vapor deposition, plating, or the like.

  In this way, by coating the upper surface of the first metal film 31 with the second metal film 33, not only the mass of the first metal film 31 adjusted by the laser beam irradiation but also the frequency variation remains unchanged. Held in. Therefore, the reference value for fine adjustment by the second metal film 33 does not fluctuate.

  The fine adjustment step B is a step of performing fine adjustment to match the target frequency f0, and by gradually reducing the thickness of the coated second metal film 33, the frequency is gradually increased, It is made to substantially coincide with f0 (step e). This step is performed at the final stage of packaging the piezoelectric vibrator 21, and an ion beam is used as a means for adjusting the thickness of the second metal film 33. As described above, since the ion beam has a slower processing speed than the laser beam, the metal film can be gradually thinned from the irradiated portion. Therefore, by controlling the irradiation range and irradiation time, it is possible to finish the surface cleanly without leaving burrs or granular metal scraps 34. The second metal film 33 is formed so as to cover not only the laser processed portion 32 where the metal marks 34 remain but also the entire first metal film 31.

  Since the surface of the crystal piece, which is the base material, is exposed in the laser processing section 32 after the actual laser processing, the mass does not change and the frequency does not vary even if this portion is irradiated with an ion beam. If the metal film area in the ion beam irradiation range varies for each crystal piece, the mass change during ion beam irradiation varies and affects the frequency adjustment accuracy. In the piezoelectric vibrator of the present invention, the second Since the entire surface of the crystal piece is covered with the metal film 33, the frequency adjustment accuracy is not affected. In addition, the adhesion of the metal debris 34 generated in the rough adjustment step A may be weakened by performing a process of thinning the entire second metal film with an ion beam. In such a case, when the second metal film 33 is formed, the thickness of the metal scrap 34 generated is reduced by taking into account the thinning by ion beam irradiation processing. A decrease can be prevented.

  The rough adjustment step A and the fine adjustment step B can be performed on the back surfaces of the vibrating arm portions 23 and 24 in the same manner.

  In the case of a tuning-fork type piezoelectric vibrator, the frequency adjustment region is effective when the frequency adjustment rate is high and the frequency adjustment region is set within a range from the center portion of the vibrating arm portions 23 and 24 that are easy to adjust to the tip corner portion. Is. Of these, the adjustment rate is highest near the corner of the tip, and decreases toward the base 22. In the present embodiment, the laser processing portion 32 is set slightly inward from the tip corners of the vibrating arm portions 23 and 24 on which the first metal film 33 is formed, but may be set at the tip corner. . Thus, the laser processing unit 32 can be arbitrarily set according to the frequency width to be adjusted.

  In addition to the form shown in FIG. 1, the tuning fork type piezoelectric vibrator has base portions 42 a, 42 b, 42 c and vibrating arm portions 43 a as shown in FIGS. 5A, 5 </ b> B, and 5 </ b> C, for example. 43b, 43c have different tip shapes. Even in the tuning fork-type piezoelectric vibrators 41a, 41b, and 41c having such various forms, the frequency adjustment regions 44a, 44b, and 44c are set at the tip portions of the vibrating arm portions, By performing the coarse adjustment step and the fine adjustment step, the oscillation frequency can be accurately adjusted to the target frequency. The same applies to a tuning-fork type piezoelectric vibrator having a structure in which three or more vibrating arms are provided.

  The frequency adjusting method according to the present invention can be applied to any piezoelectric vibrator such as a thickness shear vibration, a width longitudinal vibration, and a length longitudinal vibration other than the tuning fork type. For example, in the case of a piezoelectric vibrator of a contour vibration system, mass addition / removal of the diaphragm contour portion is effective for frequency adjustment. Therefore, a weight electrode is added to the contour portion, a rough adjustment step using a laser beam, and the second step thereafter. By applying a fine adjustment process using electrode formation and an ion beam, the oscillation frequency can be adjusted accurately and easily.

  FIG. 6A shows a width-longitudinal vibration type piezoelectric vibrator 51 that generates width-longitudinal vibration. The piezoelectric vibrator 51 includes a rectangular piezoelectric vibrating portion 53 and a pair of support arm portions 52 that support the opposing short sides of the piezoelectric vibrating portion 53. The frequency adjustment region 54 in the piezoelectric vibrating portion 53 is set along the opposing long sides, and the coarse adjustment step and the fine adjustment step are performed here.

  FIG. 6B shows a longitudinal vibration type piezoelectric vibrator 61 that generates longitudinal vibration. The piezoelectric vibrator 61 includes a vertically long piezoelectric vibrating portion 63 and a pair of support arm portions 62 that support the opposing long sides of the piezoelectric vibrating portion 63. The frequency adjustment region 64 in the piezoelectric vibrating portion 63 is set along the opposing short sides, and the coarse adjustment step and the fine adjustment step are performed here.

  FIG. 7 shows a process of adjusting the oscillation frequency in the width-longitudinal-longitudinal vibration type piezoelectric vibrator 71 in which the width-longitudinal vibration and the length-longitudinal vibration are combined. The piezoelectric vibrator 71 includes a rectangular piezoelectric vibration portion 73 having an excitation electrode formed on the surface thereof, and a support arm portion 72 that supports the opposing short sides of the piezoelectric vibration portion 73. (A). A first metal film 31 is formed on the surface of the excitation electrode along each side of the piezoelectric vibrating portion 73 (b). A laser beam mark 35 partially evaporated by irradiation with laser light is formed on the surface of the first metal film 31 (c). A second metal film 33 is formed so as to cover the laser beam scar 35, and the thickness of the second metal film 33 is adjusted to a target frequency by irradiation with an ion beam (d).

  The piezoelectric vibrators shown in FIGS. 6 and 7 belong to the contour vibration system, and the contour vibration system includes a lame mode vibration and a width slip vibration in addition to the above. Even for a piezoelectric vibrator that generates such lame mode vibration or width-slip vibration, it is possible to oscillate by providing a frequency adjustment region near each side of the piezoelectric vibration part and performing a coarse adjustment process and a fine adjustment process. The frequency adjustment accuracy can be increased. Note that the frequency adjustment region is not limited to the illustrated location in any of the flexural vibration system and the contour vibration system, and may be provided in at least one of them. The frequency is appropriately set according to the adjustment range of the oscillation frequency. The piezoelectric vibrator formed through such an adjustment step can obtain a stable oscillation frequency without fluctuation at the set target frequency.

  Further, the final adjustment is not limited to the ion beam. For example, in ultra-fine laser trimming such as φ1 to 5 μm, metal debris is not generated, and good characteristics can be maintained after adjustment. By forming the metal film, there is an effect of fixing metal scrap generated at the time of coarse frequency adjustment, which is applicable.

  As described above, according to the method for manufacturing a piezoelectric vibrator of the present invention, the first metal film formed to have a predetermined thickness on the surface of the vibrating arm portion is oscillated by partially evaporating and removing it by laser beam irradiation. The frequency can be roughly adjusted. Further, by forming the second metal film on the surface of the first metal film so as to have a predetermined thickness, it is possible to perform fine adjustment so that the oscillation frequency substantially matches the target frequency. In addition, by covering the second metal film on the first metal film, it is possible to hold the laser beam trace generated on the first metal film caused by the laser beam irradiation, and to make a fine adjustment later. Since the necessary adjustment range can be narrowed down, it is possible to perform frequency adjustment with high accuracy.

  Further, according to the piezoelectric vibrator of the present invention, since the mass of the vibrating arm portion is set in accordance with the target frequency by the first metal film and the second metal film whose mass and thickness are adjusted, the oscillation The frequency can be maintained for a long time in a stable state.

C, C ′ Frequency adjustment region F Oscillation frequency f0 Target frequency 21 Piezoelectric vibrator 22 Base 23, 24 Vibration arm (piezoelectric vibration)
25, 26 Support arm portion 27, 28 Groove portion 29, 30 Excitation electrode 31 First metal film 32 Laser processing portion 33 Second metal film 34 Metal scrap 35 Laser beam traces 41a, 41b, 41c Piezoelectric vibrators 42a, 42b, 42c Base 43a, 43b, 43c Vibrating arm (piezoelectric vibrating part)
44a, 44b, 44c Frequency adjustment area 51, 61, 71 Piezoelectric vibrator 52, 62, 72 Support arm part 53, 63, 73 Piezoelectric vibration part 54, 64, 74 Frequency adjustment area

Claims (9)

In the method of manufacturing a piezoelectric vibrator in which an oscillation frequency of the piezoelectric vibrating unit is adjusted to a predetermined target frequency by providing a frequency adjusting region in the piezoelectric vibrating unit on which the excitation electrode is formed.
A coarse adjustment step of coarsely adjusting the oscillation frequency by irradiating the first metal film with a laser beam after forming the first metal film in the frequency adjustment region;
After the second metal film is formed on the rough adjusted first metal film, the second metal film is irradiated with an ion beam to finely adjust the oscillation frequency toward the target frequency. A method for manufacturing a piezoelectric vibrator, comprising: an adjusting step. The coarse adjustment step includes the step of shifting the oscillation frequency to a frequency band lower than the target frequency by forming the first metal film;
The method for manufacturing a piezoelectric vibrator according to claim 1, further comprising: irradiating the first metal film with a laser beam to shift the oscillation frequency to a frequency band higher than the target frequency. The fine adjustment step includes a step of shifting the oscillation frequency adjusted in the coarse adjustment step to a frequency band lower than the target frequency by forming a second metal film on the surface of the first metal film.
The method of manufacturing a piezoelectric vibrator according to claim 1, further comprising: irradiating the second metal film with an ion beam to shift the oscillation frequency toward the target frequency.   The method for manufacturing a piezoelectric vibrator according to claim 1, wherein the frequency adjustment region is provided at a distal end portion of the piezoelectric vibration portion. In the piezoelectric vibrator having the frequency adjustment region in the piezoelectric vibrating portion where the excitation electrode is formed,
The frequency adjustment region includes a first metal film on which a laser beam mark for adjusting mass is formed,
The second metal film is formed on the surface of the first metal film, covers the laser beam trace, and is adjusted to have a predetermined frequency by irradiation with an ion beam. Piezoelectric vibrator.   The piezoelectric vibrator according to claim 5, wherein the frequency adjustment region is provided at a distal end portion of the piezoelectric vibrating portion.   The piezoelectric vibrator according to claim 5, wherein the piezoelectric vibrating section includes a pair of tuning fork-type vibrating arms that generate flexural vibration, and the frequency adjustment region is provided at a tip of the pair of vibrating arms.   The piezoelectric vibration unit has a vibration plate that generates any one of width-longitudinal vibration, length-longitudinal vibration, width-length-length longitudinal coupling vibration, and lame vibration, and the frequency adjustment region is provided in the vicinity of the side of the vibration plate. The piezoelectric vibrator according to claim 5.   The piezoelectric vibrator according to claim 5, wherein the second metal film is set to a thickness of 1500 mm or more.

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