JP4857491B2 - Manufacturing method of surface mount type piezoelectric vibrator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surface-mount type piezoelectric vibrator , and more particularly, a piezoelectric vibration element having a structure in which a part of a piezoelectric substrate is an ultra-thin vibrating portion reduces bending deformation of the piezoelectric substrate to improve various characteristics and reliability. The present invention relates to a high-frequency piezoelectric vibrator.
The present invention also relates to a surface-mounted piezoelectric vibrator , and in particular, solves various problems that have conventionally been caused when Au bumps are used as means for connecting a piezoelectric vibration element having a fundamental resonance frequency of 300 MHz or more in a package. The present invention relates to a surface mount type piezoelectric vibrator.
[0002]
[Prior art]
In recent years, in various electronic devices and communication devices, with higher performance, increased amount of information to be handled, higher speed of data processing, etc., higher frequency of use, miniaturization, and higher reliability are required. Similarly, there is a strong demand for higher frequency, smaller size, and higher reliability for piezoelectric devices such as crystal resonators and crystal filters used as reference frequency sources and frequency control means in the apparatus.
These piezoelectric devices have a configuration in which a piezoelectric vibration element in which an excitation electrode is formed on a main surface of a piezoelectric substrate such as quartz is hermetically sealed in a package.
[0003]
[First Conventional Example]
FIG. 7 is a cross-sectional view of an AT-cut quartz crystal resonator element having an ultra-thin part for the purpose of increasing the frequency.
This crystal vibration element is a vibration element using the fundamental wave thickness shear vibration wave of AT cut crystal, and since the resonance frequency is inversely proportional to the plate thickness, in order to increase the frequency while maintaining the mechanical strength, One main surface of the quartz substrate 101 having a thickness of 80 μm is recessed by etching, the bottom surface of the recessed portion 102 is used as an ultrathin vibrating portion 103, and the outer periphery of the vibrating portion 103 is supported over the entire circumference. It has a structure in which the meat annular surrounding portion 104 is integrated.
Here, since the quartz substrate 101 has anisotropy in the crystal axis direction, the peripheral wall portions 102a and 102b of the concave portion 102 have a property of being etched with different inclinations in the thickness direction depending on the crystal axis direction.
A main surface electrode 105 is formed on one main surface (flat surface) of the quartz substrate 101, and a back surface electrode 106 is formed on the other main surface (concave surface).
For example, when a fundamental wave thickness shear vibration wave of 622 MHz is obtained, the plate thickness H of the vibration part 103 is about 2 μm.
However, when the length L of the vibrating portion 103 is, for example, 1 mm, the ratio L / H of the length L to the plate thickness H of the vibrating portion 103 is about 500, the mechanical rigidity is deteriorated, and the self-weight or main surface electrode 105, Due to the weight of the back electrode 106, the vibration part 103 is bent as shown in the figure.
When the amount of deflection of the vibration part was measured with an optical interferometer, the maximum amount of deflection W at the center of the vibration part was about 50 to 80 nm.
In this case, the maximum deflection amount W of the vibration part 103 corresponds to 2.5 to 4.0% of the plate thickness H of the vibration part, and a static load, that is, internal strain remains in the vibration part.
In such a case, there is a problem that not only normal energy confinement thickness vibration cannot be obtained but also reliability such as long-term aging is deteriorated.
[0004]
[Second Conventional Example]
Next, FIGS. 8A and 8B are perspective views of the front and back surfaces of an AT-cut crystal resonator element having an ultra-thin portion for the purpose of increasing the frequency, and this crystal resonator element 111 is the basic structure of an AT-cut crystal. Since the resonant frequency is inversely proportional to the plate thickness, the resonant frequency of the quartz crystal substrate 112 constituting the quartz crystal vibrating element 111 is designed to increase the frequency while maintaining the mechanical strength. One main surface is recessed by etching, and the bottom surface of the recessed portion 113 is an ultrathin vibrating portion 113a, and a thick annular surrounding portion 114 that supports the outer periphery of the vibrating portion 113a over the entire circumference is provided. It is integrated.
Furthermore, on one main surface (concave surface) of the quartz substrate 112, a main surface electrode (excitation electrode) 115, a lead electrode 115a extending from the main surface electrode 115 toward the peripheral edge of the substrate, and an end of the lead electrode 115a A pad electrode 115b located in the area and another pad electrode 116c are formed. On the vibration portion 113a on the back surface side of the quartz substrate 112, there are a back electrode 116, a lead electrode 116a extending from the back electrode 116 toward the periphery, and a back surface side pad electrode 116b positioned at an end of the lead electrode 116a. The back-side pad electrode 116b is electrically connected to the pad electrode 116c formed on the main surface side through the notch 117.
Further, the pad electrodes 115b and 116c are formed by depositing a conductive metal such as aluminum by vapor deposition in order to form the Au bump 118, and the back-side pad electrode 116b is formed by vapor deposition in order to improve the conductivity of the notch 117 portion. Yes.
The Au bump 118 is bonded to the pad electrodes 115b and 116c by a diffusion phenomenon caused by heating, pressurization, and application of ultrasonic waves by applying a wire bonding technique.
FIG. 9 is a cross-sectional view showing the structure of a surface-mounted crystal resonator using the crystal resonator element 111.
After the crystal resonator element 111 shown in FIG. 8 is accommodated in the ceramic package 120, the upper surface opening of the ceramic package 120 is hermetically sealed with a metal upper lid 121.
The ceramic package 120 includes a bottom ceramic substrate 121, a ceramic annular frame 122 integrated on the outer periphery of the upper surface of the ceramic substrate 121, and a seam that is annularly fixed on the frame 122 for seam welding the upper lid 121. It consists of a ring 123 and has a recess for accommodating the crystal resonator element 1 at the center as a whole, and has a box shape with an annular portion on the outer periphery.
Internal terminals 124 and 125 formed of Au metallization are exposed on the upper surface of the ceramic substrate 121, and each is connected to an external terminal (not shown) provided on the bottom surface of the package.
[0005]
FIG. 10 is a diagram illustrating a process of connecting the crystal resonator element 111 into the package 120. First, the flat surface side of the crystal resonator element 111 is sucked by the collet 130 having the suction hole 131 opened in the tip surface for suction. . Subsequently, the collet 130 is moved into the recess of the package 120, and the pad electrodes 115b and 116c located on the concave surface side of the adsorbed crystal resonator element 111 are respectively connected to the input / output internal terminals 124 and 125 on the inner bottom surface of the package 120. Position one-on-one. Subsequently, both of them are utilized by utilizing a diffusion phenomenon caused by heating, pressurization, and application of ultrasonic waves using a flip chip mounting technique through each Au bump 118 formed in advance on each pad electrode 115b, 116c. Join.
Here, the reason why the Au bump 118 is used as a bonding means between the crystal resonator element 111 and the package 120 is that, when the Au bump 118 is used, the conductivity is improved as compared with the case where a conductive adhesive is used. This is because local bonding becomes possible and no outgas is generated, which contributes to higher frequency, smaller size, and higher reliability of the device.
However, when the crystal resonator element 111 is bonded to the package 120, if the crystal resonator element 111 has a resonance frequency of 300 MHz or more, the thickness of the vibration portion 113a is 5 μm or less, and the vibration portion 113a is attracted and pressurized by the cores 130. The bonding is completed in a state where the wire is damaged or excessive distortion occurs.
In the experiment by the present inventor, this distortion was large enough to be confirmed with the naked eye.
As described above, when the strain remains in the vibration portion 113a, the crystal resonator element 111 having a property that the frequency fluctuates as the residual strain is released due to a change with time or a thermal change is a resonance immediately after bonding. There was a problem that the frequency could not be maintained and the stability deteriorated.
[0006]
[Problems to be solved by the invention]
The present invention has been made to solve the above problems, and the first problem of the present invention corresponding to the first conventional example is that the outer periphery of the ultrathin vibrating portion is formed with a thick annular surrounding portion. High-performance and high-reliability ultra-high-frequency piezoelectric vibration by increasing the mechanical rigidity of the piezoelectric substrate and preventing bending deformation of the vibration part. It is an object to provide an element.
Next, a second problem of the present invention corresponding to the second conventional example is that Au bumps are used as means for connecting the piezoelectric vibration element in the package, and the piezoelectric vibration element adsorbed by the collet is placed on the terminal in the package. An object of the present invention is to provide a surface-mount type piezoelectric vibrator that solves the problem of damage to an ultrathin vibrating portion and excessive distortion that occur when bonding using Au bumps while being pressed.
[0007]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the invention according to claim 1 is characterized in that the vibration portion disposed on the bottom surface of the recessed portion in which the main surface of the piezoelectric substrate is recessed, and the periphery of the vibration portion are integrally supported, and the vibration and holding means thicker than the thickness of the parts, before Symbol both surfaces disposed so as to respectively face each other electrode of the vibrating portion, one surface of the piezoelectric vibrating element provided with electrical surface-mount type package A mechanically connected surface-mount type piezoelectric vibrator having a suction hole on a tip surface, and a collet having a shape in which the outer shape of the tip surface substantially matches the outer contour of the piezoelectric vibration element, The main surface of the piezoelectric vibration element opposite to the recessed portion is sucked and held so that the vibration section and the suction hole do not interfere with each other, and the piezoelectric vibration element is held in the surface mounted package in the sucked and held state. It is characterized by being connected by bumps.
The invention of claim 2 is characterized in that the holding means is a thick annular portion made of a piezoelectric material.
According to a third aspect of the present invention, a ratio L / H between the length L of the vibrating portion and the thickness H of the vibrating portion satisfies 0 <L / H ≦ 250.
The invention according to claim 4 is characterized in that the fundamental resonance frequency of the piezoelectric vibration element is 300 MHz or more.
The invention of claim 5 is characterized in that the piezoelectric material is an AT cut crystal.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
[Embodiment corresponding to first conventional example]
Hereinafter, a first embodiment of the present invention will be described in detail based on an example shown in the drawings.
FIG. 1 is a cross-sectional view of an AT-cut quartz crystal vibrating element having an ultra-thin part for the purpose of increasing the frequency.
This quartz resonator element 1 uses the fundamental thickness shear vibration wave of AT-cut quartz, and its resonance frequency is inversely proportional to the plate thickness. Therefore, in order to increase the frequency while maintaining the mechanical strength, the thickness is 80 μm. The main surface of the quartz substrate 2 is recessed by etching to form a recessed portion 3, and the bottom surface of the recessed portion 3 is used as an ultrathin vibrating portion 4, and the outer periphery of the vibrating portion 4 extends over the entire circumference. The thick ring-shaped surrounding portion 5 to be supported is integrated with the vibrating portion 4.
Here, since the quartz substrate 2 has anisotropy in the crystal axis direction, the peripheral wall portions 3a and 3b of the recessed portion 3 have a property of being etched with different inclinations in the thickness direction depending on the crystal axis direction.
Further, a main surface electrode 10 is formed on one main surface (flat surface) of the quartz substrate 2, and a back surface electrode 11 is formed on the other main surface (concave surface). Lead terminals (not shown) extend from the electrodes 10 and 11 toward the edge of the substrate, and are electrically connected to the electrodes in the package when mounted in a package (not shown).
In the present invention, in order to obtain a resonance frequency of 300 MHz or higher, the plate thickness of the vibrating portion 4 is ultrathin. For example, when a fundamental wave thickness shear vibration wave of 622 MHz is obtained, the plate thickness H of the vibration part 4 is about 2 μm.
The characteristic configuration of the present invention is that the length L of the vibration part 4 is set to 0.5 mm or less, that is, the ratio L / H of the length L to the plate thickness H of the vibration part 4 is set to 250 or less. With such a configuration, the mechanical rigidity of the piezoelectric substrate 2 is increased, and the flexure deformation of the vibration part 4 is prevented, so that high performance and high reliability can be obtained. Here, the length L includes not only the length of the vibrating portion 103 when viewed from the front shown in FIG. 1, but also the length L when viewed from the side surface orthogonal to FIG.
[0009]
FIG. 2 is a table showing the results of material mechanics analysis on the tendency of increase in the maximum deflection amount W at the center of the vibration portion with respect to the ratio L / H.
The maximum deflection amount W has an exponential relationship with the value of the above ratio, and increases rapidly when L / H = 250 or more. This is the same in both cases for the UHF band, that is, the vibration element having a resonance frequency of 300 MHz or more.
Therefore, by setting the ratio L / H to 250 or less, the mechanical rigidity of the vibrating part is not deteriorated even when an ultra-high frequency of 300 MHz or more is achieved, and the residual internal strain that causes deflection is reduced. In addition, normal energy confinement thickness vibration can be obtained, and reliability such as long-term aging is not deteriorated.
It should be noted that when obtaining an ultra-high frequency fundamental wave thickness vibration, the energy can be sufficiently confined in the vicinity of the main surface electrode 10 and there is no need to worry about energy leakage to the end of the vibration part. Is only required to be slightly larger than the main surface electrode 10, and by reducing L / H to the limit, the influence of deflection can be ignored.
This suggests the possibility of downsizing the vibration element 1 at the same time.
In the above embodiment, the present invention has been described as an example of applying the present invention to an AT-cut crystal resonator element having an ultrathin vibrating portion, but the present invention is not limited to this, It is self-evident that the electrode formed on one side may be a split-mode dual mode filter.
Moreover, even if a space is ensured by means of mechanical polishing, etc., even if a space is ensured by holding the outer peripheral edge of the vibration element by other holding means, etc. It is obvious that the configuration of the present invention can be applied to solve the same problem due to the deflection deformation of the portion.
The cut angle of the piezoelectric substrate may be a crystal other than the AT cut or a piezoelectric substrate other than the crystal.
Next, the piezoelectric vibration element 1 having the above-described configuration can be hermetically sealed in a ceramic package to form a piezoelectric vibrator as a surface-mount type piezoelectric device.
[0010]
[Embodiment corresponding to second conventional example]
Next, a second embodiment of the present invention will be described in detail based on the illustrated embodiment.
FIG. 3 is a perspective view of the front and back surfaces of an AT-cut quartz crystal resonator element having an ultra-thin vibrating portion for the purpose of increasing the frequency, and this crystal resonator element 21 is a vibration utilizing the fundamental wave thickness shear vibration wave of an AT-cut crystal. Since the resonance frequency is inversely proportional to the plate thickness, one main surface of the crystal substrate 22 constituting the crystal resonator element 21 is recessed by etching in order to increase the frequency while maintaining the mechanical strength. The concave portion 23 is formed, and the bottom surface of the concave portion 23 is formed as an ultrathin vibrating portion 24 and a thick annular surrounding portion 25 that supports the outer periphery of the vibrating portion 24 over the entire circumference is integrated. ing.
Further, as shown in FIG. 3 (a), on one main surface (concave surface) of the quartz substrate 22, a main surface electrode (excitation electrode) 25, and a lead electrode 26a drawn from the main surface electrode toward the substrate edge. And a main surface side pad electrode 26b formed by vapor deposition on the end portion of the lead electrode 26a. The pad electrode 26b is conductively connected to the pad electrode 26c on the back side of the substrate through a notch 27 at the edge of the substrate.
As shown in FIG. 3B, on the back surface of the quartz substrate 22, a back electrode 31 formed at a position facing the main surface electrode 25, a lead electrode 32a extending from the back electrode 32, and a lead electrode And a pad electrode 32b formed by thick deposition on the edge of 32a. Au bumps 40 are formed on both pad electrodes 26c and 32b on the back side. The Au bump 40 is bonded to the pad electrodes 26c and 32b by a diffusion phenomenon caused by heating, pressurization, and application of ultrasonic waves by applying a wire bonding technique.
The pad electrodes 26b, 26c, and 32b are thickened by vapor deposition in order to form the Au bump 40 and improve the conductivity of the notch 27.
[0011]
FIG. 4 is a cross-sectional view showing the structure of a surface-mounted crystal resonator as an example of a piezoelectric device using the crystal resonator element 21.
After the crystal resonator element 21 shown in FIG. 3 is accommodated in the ceramic package 50, the upper surface opening of the ceramic package 50 is hermetically sealed with a metal upper lid 51.
The ceramic package 50 is annularly enclosed on the frame 53 for seam welding the ceramic substrate 52 constituting the bottom plate, the ceramic annular frame 53 integrated on the outer periphery of the upper surface of the ceramic substrate 52, and the upper lid 51. It consists of a fixed seam ring 54 and has a recess for accommodating the crystal resonator element 21 at the center as a whole, and has a box shape with an annular portion on the outer periphery.
Internal terminals 56 and 57 formed of Au metallization are exposed on the upper surface of the ceramic substrate 52, and are electrically connected to external terminals (not shown) provided on the outer bottom surface of the package. The positions and shapes of the internal terminals 56 and 57 are set in advance so that the internal terminals 56 and 57 can be connected to the pad electrodes 26c and 32b on the back surface side of the crystal resonator element 21 in a one-to-one corresponding positional relationship.
In this crystal resonator, the internal terminals 56 and 57 are connected to the pad electrodes 26c and 32b by using the Au bump 40 with the flat back surface of the crystal resonator element 21 facing the bottom surface of the package, and the package is recessed. The structure is hermetically sealed with a lid 51.
[0012]
FIG. 5 is a diagram showing a process of connecting the crystal resonator element 21 sucked and held by the collet 61 into the package 50, and the collet 61 connected to a vacuum pump (not shown) is vacuumed on the flat front end surface for suction. A suction hole 62 that communicates with the pump and receives negative pressure is provided. The front end surface of the collet 61 is brought into close contact with the concave surface (main surface) side of the crystal resonator element and is held by suction, and the back surface side pad electrodes 26c and 32b previously provided with Au bumps 40 and the input / output internal terminals 56 on the ceramic package side. , 57 are brought into contact with each other through the Au bump 40, and are electrically and mechanically connected by utilizing a diffusion phenomenon caused by heating, pressurizing, and applying ultrasonic waves using a flip chip mounting technique.
The reason for using the Au pump 40 is that the conductivity is improved, local bonding is possible, and there is no outgas, compared with the case where a conductive adhesive is used. Contributes to higher reliability and higher reliability.
Here, the characteristic configuration of the embodiment of the present invention is such that the surface of the crystal resonator element 21 (surface to be attracted) to which the collet 60 is attracted is a concave surface, and contact between the vibrating portion 24 and the tip surface of the collet 60 is avoided. It is to have done.
The shape of the bottom surface of the tip surface of the collet 60 is a shape that substantially matches the outer contour of the crystal resonator element. When the collet tip surface is brought into close contact with the main surface side of the crystal resonator element as shown in the drawing, the suction hole 62 is made of crystal The entire main surface including the recess 23 of the substrate faces and contacts and sucks it, so that it can be reliably held. On the other hand, the collet tip surface does not come into direct contact with the vibrating portion 24, so that the vibrating portion 24 is not deformed or damaged by the suction force from the suction hole or the applied pressure from the collet tip surface.
That is, if the crystal resonator element 21 has a fundamental resonance frequency of 300 MHz or more, the thickness of the vibrating part 24 becomes 5 μm or less and the mechanical strength is significantly reduced. In this case, the vibrating part 24 is attracted and pressurized by the collet 60. Since no direct load acts on the joint, it is possible to complete the joining without damaging the vibration part or causing excessive distortion.
Therefore, since the distortion due to the bonding does not remain in the vibration part 24, the crystal resonator element 21 can maintain the resonance frequency immediately after the bonding and ensure excellent stability even with a change with time or a thermal change.
[0013]
FIG. 6 shows another embodiment, and the flat back surface side of the crystal resonator element 21 may be adsorbed by the tip surface of the collet 60 as shown in FIG. In this case, the shape and position of the vibration part are set in advance so as to avoid the suction hole 62 so that the suction hole 62 of the collet 60 and the vibration part 24 do not interfere with each other. In this way, at least damage and distortion of the vibration part 24 due to adsorption can be avoided, and it is possible to eliminate the inconvenience that excitation becomes impossible and the stability of the resonance frequency deteriorates due to aging and thermal changes.
In the present embodiment, the present invention has been described as an example in which the present invention is applied to an AT-cut crystal resonator element having an ultrathin vibrating portion, but the present invention is not limited to this, Obviously, the electrode formed on one side may be a split-mode dual mode filter.
The piezoelectric substrate to be used may be a crystal having a cut angle other than AT cut or a piezoelectric substrate other than crystal.
[0014]
【Effect of the invention】
The first embodiment of the present invention is a piezoelectric vibration element comprising a piezoelectric substrate having a structure in which the outer periphery of an ultrathin vibrating portion having a fundamental resonance frequency of 300 MHz or higher is integrally supported by a thick annular surrounding portion. Therefore, the ratio L / H between the length L of the vibration part and the thickness H of the vibration part is set to be 250 or less, so that the mechanical rigidity of the piezoelectric substrate is increased to prevent the deformation of the vibration part. Thus, it is possible to provide a high-performance and high-reliability ultrahigh-frequency piezoelectric vibration element. Therefore, there is a remarkable effect in providing a high-performance and high-reliability ultrahigh-frequency piezoelectric vibrator.
In the second embodiment of the present invention, the principal surface of the piezoelectric substrate is recessed, the bottom surface of the recessed portion is an ultrathin vibrating portion, and an electrode is provided on each of the principal surface and the back surface. Ultra-high-frequency piezoelectric vibration element that is electrically and mechanically connected by Au bumps in a surface-mount package with the main surface or back surface adsorbed and held by a collet having a suction hole on the front end surface Since the ultra-thin vibrating portion is disposed at a position where it does not interfere with the suction hole when attracted by the collet, when the piezoelectric vibration element is assembled in the ceramic package, Distortion does not occur and excitation cannot be performed, and the problem that the stability of the resonance frequency is deteriorated due to change with time or heat can be solved. Therefore, the present invention is remarkably effective in providing a high-performance and highly reliable surface-mount type super-high frequency piezoelectric resonator that sufficiently exhibits the effect of using the Au pump.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an AT-cut crystal resonator element as an embodiment of the present invention.
FIG. 2 is a diagram showing a relationship between a maximum deflection at the center of a vibration part and a size ratio.
FIGS. 3A and 3B are perspective views showing configurations of a main surface side and a back surface side of a crystal resonator element according to an embodiment of the present invention. FIGS.
4 is a cross-sectional view showing a configuration of a crystal resonator in which the crystal resonator element of FIG. 2 is sealed in a ceramic package.
FIG. 5 is a cross-sectional view showing a state in which the quartz resonator element of the present invention is adsorbed by a collet and assembled in a package.
6 is a view showing a modification of FIG.
FIG. 7 is an explanatory diagram of a first conventional example.
FIGS. 8A and 8B are perspective views showing configurations of a main surface side and a back surface side of a crystal resonator element of a second conventional example.
9 is a cross-sectional view of a crystal resonator in which the crystal resonator element of FIG. 8 is housed in a package.
FIG. 10 is a diagram for explaining a defect of a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Crystal resonator element (piezoelectric resonator element), 2 Crystal substrate (piezoelectric substrate), 3 Recessed part, 4 Vibration part, 5 Ring surrounding part (annular part), 10 Main surface electrode, 11 Back electrode, 21 Crystal oscillator, 22 Crystal substrate, 23 concave part, 24 vibrating part, 25 annular surrounding part, 26a lead electrode, 26b pad electrode, 26c pad electrode, 27 notch, 32a lead electrode, 32b pad electrode, 40 Au bump, 50 ceramic package, 51 top cover , 52 Ceramic substrate, 53 Frame, 54 Seam ring, 56, 57 Internal terminal, 61 Collet, 62 Suction hole.

Claims (5)

A vibrating portion disposed to the main surface of the piezoelectric substrate to the bottom surface of the concave portion was allowed concave, the periphery of the vibrating portion is supported integrally, and holding means thicker than the thickness of the vibrating section, before Symbol vibration A surface-mount type piezoelectric vibrator in which one surface of a piezoelectric vibration element provided with electrodes provided so as to face each other on both surfaces of a part is electrically and mechanically connected in a surface-mount type package Because
With the collet having a suction hole in the tip surface and the outer shape of the tip surface substantially matching the outer contour of the piezoelectric vibration element , the concave portion is defined so that the vibration part and the suction hole do not interfere with each other. Adsorb and hold the main surface of the piezoelectric vibration element on the opposite side ,
A method of manufacturing a surface-mount type piezoelectric vibrator, wherein the piezoelectric vibration element is connected to the surface-mount package by a bump in a state of being held by suction.   2. The method for manufacturing a surface-mounted piezoelectric vibrator according to claim 1, wherein the holding means is a thick annular portion made of a piezoelectric material.   3. The surface-mount type piezoelectric vibration according to claim 1, wherein a ratio L / H of a length L of the vibration part and a thickness H of the vibration part satisfies 0 <L / H ≦ 250. Child manufacturing method.   The method for manufacturing a surface-mount type piezoelectric vibrator according to claim 1, wherein a fundamental wave resonance frequency of the piezoelectric vibration element is 300 MHz or more.   The method for manufacturing a surface-mount piezoelectric vibrator according to claim 1, wherein the piezoelectric material is an AT-cut quartz.

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