JP2004297372A - Piezoelectric device and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a substantial mounting area by realizing the thickness reduction in a method for manufacturing a piezoelectric device having a piezoelectric element such as a piezoelectric oscillating piece formed of a piezoelectric crystal such as rock crystal and the piezoelectric device. <P>SOLUTION: A tuning fork piezoelectric vibrator 10 is composed of the tuning fork piezoelectric oscillating piece 20 and a package 30. The package 30 has a plate-like base 31 and a plate-like lid body 32. The plate-like base 31 and the plate-like lid body 32 are joined by a low melting point glass layer 33. It has an oscillation space of the tuning fork piezoelectric oscillating piece 20 in its inside formed into a box shape. The low melting point glass layer 33 includes a filler. It can make the distance between the tuning fork piezoelectric oscillating piece 20 and the plate-like lid body 32 constant by the filler of the low melting point glass layer 33 covering the frame of the tuning fork piezoelectric oscillating piece 20. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a piezoelectric device having a piezoelectric element such as a piezoelectric vibrating reed formed from a piezoelectric crystal such as quartz crystal, and a piezoelectric device.
[0002]
[Prior art]
Piezoelectric crystal vibrators, particularly tuning-fork type piezoelectric vibrators, are known as those capable of easily obtaining an accurate clock frequency. In recent years, the tuning fork type piezoelectric vibrator has been reduced in size and thickness in response to the reduction in size and thickness of electronic devices, and a so-called surface mount type has been developed. This surface mount type tuning fork type piezoelectric vibrator has a tuning fork type piezoelectric vibrating piece mounted on the bottom of the package in a cantilever manner so that the surface of the tuning fork type piezoelectric vibrating piece is parallel to the bottom surface of the package. Implemented by Further, as a conventional tuning-fork type piezoelectric vibrator, there is a tuning-fork type piezoelectric vibrating piece in which a concave portion is formed on a package bottom surface corresponding to a tip end of a vibrating arm portion (Patent Document 1). This is to prevent the tip of the vibrating arm portion of the tuning fork type piezoelectric vibrating piece from bending and colliding against the package bottom surface when an impact such as dropping acts on the tuning fork type piezoelectric vibrator.
[0003]
On the other hand, there is a tuning-fork type piezoelectric vibrator shown in FIGS. 8 and 9 (Patent Document 2). FIG. 8 is a plan view showing an example of a conventional tuning-fork type piezoelectric vibrator in a partially broken manner. FIG. 9 is a longitudinal sectional view of an example of a conventional tuning-fork type piezoelectric vibrator. The conventional tuning-fork type piezoelectric vibrator 100 includes a tuning-fork type piezoelectric vibrating piece 115 and two cases 120 and 121 as shown in FIGS. The tuning-fork type piezoelectric vibrating piece 115 is formed of a piezoelectric crystal such as quartz, and includes a base 110 and vibrating arms 111 and 112 formed so as to protrude from the base 110. Is provided. The tuning-fork type piezoelectric vibrating reed 115 has a frame 114 formed so as to be connected to the terminal side of the base 110 and surrounding the tuning-fork type piezoelectric vibrating reed main body 113. The tuning fork type piezoelectric vibrator 100 is bonded and sealed with the frame 114 sandwiched between two cases 120 and 121. Further, in the tuning fork type piezoelectric vibrator 100, projection regions 114a and 114b where the frame portion 114 partially protrudes from the holding portions of the cases 120 and 121 are formed (Patent Document 2). Reference numerals 116 and 117 shown in FIG. 9 are external electrodes to be mounted on a substrate.
[0004]
According to the above-mentioned conventional tuning fork type piezoelectric vibrator 100, since the projections 114a and 114b are provided by enlarging the width of the frame portion 114, even if the metal bonding material protrudes, the metal bonding on the upper case 120 side is performed. Since the material and the metal bonding material on the lower case 121 side are not bonded, there is an advantage that a short circuit between the electrodes does not occur.
[0005]
[Patent Document 1] Japanese Patent Application Laid-Open No. 2001-332952 [Patent Document 2] Japanese Patent Application Laid-Open No. 56-61820 [Problems to be Solved by the Invention]
[0006]
By the way, in a conventional tuning fork type piezoelectric vibrator, as described in Patent Document 1, generally, a tuning fork type piezoelectric vibrating piece is mounted in a cantilever shape via a base. For this reason, in the conventional tuning-fork type piezoelectric vibrator, the tuning-fork type piezoelectric vibrating piece mounted in the package has a low parallelism and may be mounted obliquely. Therefore, in the conventional tuning-fork type piezoelectric vibrator, the oscillation arm may come into contact with the bottom surface of the package or the lid, and oscillation may be stopped. Further, in the conventional tuning-fork type piezoelectric vibrator, a recess is formed on the bottom surface of the package in order to avoid contact between the vibrating arm and the bottom surface of the package. The concave portion needs to be set to a depth that can reliably prevent the contact between the vibrating arm portion and the package, and it has been difficult to reduce the thickness of the tuning-fork type piezoelectric vibrator. Also, in the conventional tuning-fork type piezoelectric vibrator, since the base from which the vibrating arm portion is formed is mounted (fixed) on the bottom surface of the package, there is a problem that the vibration leakage is large and the crystal impedance (CI) value increases. Was. Further, the conventional tuning-fork type piezoelectric vibrator has a structure in which the two electrodes of the tuning-fork type piezoelectric vibrating reed and the mounting electrode on the package side are connected to each other with a conductive adhesive. Since the distance between the mounting electrodes on the side was short, there was a risk that the conductive adhesive would protrude and short-circuit would occur between the electrodes.
In view of the above problems, an object of the present invention is to provide a tuning fork type piezoelectric vibrator which can be made thinner and has high accuracy and stability.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a method for manufacturing a piezoelectric device according to the present invention includes, on a plate-shaped base, a mounting step of mounting a piezoelectric element having an outer shape smaller than the plate-shaped base, before or after this mounting step, An application step of applying an adhesive to a peripheral portion of the plate-shaped lid and the plate-shaped base larger than the piezoelectric element, and joining the plate-shaped base and the plate-shaped lid via the adhesive; A sealing step of forming a vibration space of the piezoelectric element with the plate-shaped base, the plate-shaped lid, and the adhesive.
[0008]
According to the present invention, the package for mounting the piezoelectric element includes a plate-shaped base, a plate-shaped lid, and an adhesive, and has a substantially two-layer structure of the plate-shaped base and the plate-shaped lid. It can be. Therefore, the thickness of the piezoelectric device can be reduced, and the thickness can be reduced. In addition, since the piezoelectric element has a smaller outer shape than the plate-shaped base and the plate-shaped lid, it does not protrude from the package, and short-circuits even when it comes into contact with other electronic components when mounted on the board. This does not occur, and the actual mounting area can be reduced.
[0009]
In the sealing step, the adhesive to the plate-like lid can be applied to an application width in which a part of the adhesive hangs over or flows over the non-vibrating portion provided on the peripheral edge of the piezoelectric element. Thereby, since the adhesive is interposed between the plate-shaped lid and the piezoelectric element, the plate-shaped lid can be prevented from contacting the piezoelectric element, and the piezoelectric element can be vibrated stably. In addition, it is preferable to use an adhesive containing a filler. Thus, the filler contained in the adhesive serves as a gap forming material, so that the distance between the plate-shaped lid and the piezoelectric element can be easily maintained constant, and the thickness can be accurately set. And the adhesive may be an inorganic adhesive. When an inorganic adhesive such as low melting point glass is used, the vibration space of the piezoelectric element can be easily vacuum-sealed, and a tuning fork type piezoelectric vibrator or the like can be obtained.
[0010]
The piezoelectric device according to the present invention includes a plate-shaped base, a piezoelectric element having an outer shape smaller than the plate-shaped base, and a piezoelectric element mounted on a mount portion of the plate-shaped base, and formed larger than the piezoelectric element, and an adhesive. And a vibration space for the piezoelectric element formed by the plate-like lid, the plate-like base, and the adhesive. As a result, the tuning fork type piezoelectric vibrating reed can be mounted in parallel with the bottom surface of the package, the thickness of the piezoelectric device can be reduced, and the actual mounting area can be reduced. Further, since the piezoelectric device of the present invention is mounted at a portion of the piezoelectric element that is remote from the vibrating arm, vibration leakage is small, and the crystal impedance (CI) value can be reduced.
[0011]
A part of the adhesive may be provided so as to cover at least a part of the upper surface of the non-vibration part provided on the peripheral edge of the piezoelectric element. Thereby, since the adhesive is interposed between the plate-shaped lid and the piezoelectric element, the plate-shaped lid can be prevented from contacting the piezoelectric element, and the piezoelectric element can be vibrated stably. The adhesive desirably contains a filler. This makes it possible to easily maintain a constant distance between the plate-shaped lid and the piezoelectric element. As the adhesive, an inorganic adhesive can be used. This enables vacuum sealing.
[0012]
As the piezoelectric element, an AT-cut vibrating reed, an inverted mesa-type AT-cut vibrating reed, a SAW element, or the like can be used. Further, the piezoelectric element may be a tuning fork type piezoelectric vibrating piece with a frame. In other words, the piezoelectric element is a tuning-fork type piezoelectric vibrating reed comprising a piezoelectric vibrating reed main body having a base and a vibrating arm protruding from the base, and a frame connected to the base and surrounding the piezoelectric vibrating reed main body. May be. By mounting the tuning fork type piezoelectric vibrating reed via a frame portion which is a non-vibrating portion, vibration leakage from the piezoelectric vibrating reed main body can be prevented, and a piezoelectric device having excellent vibration characteristics can be obtained.
BEST MODE FOR CARRYING OUT THE INVENTION
[0013]
Hereinafter, preferred embodiments of a method for manufacturing a piezoelectric device and a piezoelectric device according to the present invention will be described with reference to the accompanying drawings.
1 to 3 are diagrams illustrating a piezoelectric device according to an embodiment of the present invention. In this embodiment, a tuning fork type piezoelectric vibrator will be described as an example. Here, FIG. 1 is a longitudinal sectional view showing a piezoelectric vibrator which is a piezoelectric device according to an embodiment of the present invention. FIG. 2 is an enlarged sectional view showing a part of FIG. FIG. 3 is a sectional view taken along line AA of FIG.
[0014]
In these figures, a tuning-fork type piezoelectric vibrator 10 according to an embodiment of the present invention includes a tuning-fork type piezoelectric vibrating piece 20 which is a piezoelectric element and a package 30. The tuning fork type piezoelectric vibrating piece 20 is formed of a piezoelectric crystal such as quartz. The tuning-fork type piezoelectric vibrating reed 20 has a piezoelectric vibrating reed main body 25 having a base 21 and a pair of vibrating arms 22 and 23 protruding from the base 21 (see FIG. 3). Further, the tuning-fork type piezoelectric vibrating reed 20 has a frame portion 24 which is a non-vibrating portion formed in a shape surrounding the piezoelectric vibrating reed main body 25. The frame portion 24 is formed integrally with the piezoelectric vibrating reed main body 25 as shown in FIG. The frame 24 includes a base-side joint 28 connected to the base 21 of the piezoelectric vibrating reed main body 25, and two bridges 26 and 27 extending from both sides of the base-side joint 28. , And a front end side joint portion 29 provided at the front end of each of the bridge portions 26 and 27.
[0015]
The package 30 includes a flat base (plate base) 31 made of, for example, ceramics such as alumina, and a flat lid (plate lid) 32 formed of glass. The package 30 has a box shape, and a low-melting glass layer 33 made of a low-melting glass as an inorganic adhesive is interposed between a plate-shaped base 31 and a plate-shaped lid 32. The low-melting-point glass layer 33 maintains a space between the plate-shaped base 31 and the plate-shaped lid 32 at a predetermined interval, and forms a vibration space of the tuning-fork type piezoelectric vibrating piece 20 in the package 30.
[0016]
As shown in FIG. 3, the low melting point glass layer 33 covers a part of the upper surface of the frame portion 24 provided on the tuning fork type piezoelectric vibrating piece 20. The low-melting glass layer 33 includes a vitreous portion 33a and a filler 33b, as shown in FIG. The filler 33b functions as a gap forming material, and has a diameter of, for example, several tens of μm. For this reason, the filler 33 b present on the upper surface of the tuning-fork type piezoelectric vibrating reed 20 keeps the distance between the tuning-fork type piezoelectric vibrating reed 20 and the plate-shaped lid 32 constant. Therefore, the plate-shaped lid 32 is prevented from coming into contact with the tuning-fork type piezoelectric vibrating piece 20, and the tuning-fork-type piezoelectric vibrating piece 20 can be vibrated stably.
[0017]
As shown in FIG. 1, mount electrodes 34 and 35, which are a pair of mount portions, are provided on the upper surface of the plate-like base 31 at a predetermined interval. Joints 28 and 29 provided at both ends of the frame 24 of the tuning-fork type piezoelectric vibrating piece 20 are mounted on these mount electrodes 34 and 35. That is, the joining portions 28 and 29 of the tuning-fork type piezoelectric vibrating piece 20 are fixed to the mount electrodes 34 and 35 by the conductive adhesive m. The joints 28 and 29 are provided with connection electrodes connected to excitation electrodes (not shown) formed on the vibrating arms 22 and 23. These connection electrodes are electrically connected to the mount electrodes 34 and 35 by starting the conductive adhesive m. The package 30 is provided with a sealing hole 40 for vacuum sealing at the center of the plate-like base 31. That is, in the package 30, after the plate-shaped base 31 and the plate-shaped lid 32 are joined by the low-melting glass layer 33, the metal balls (not shown) arranged in the sealing holes 40 are melted in vacuum, The sealing hole 40 is closed and the inside is vacuum sealed. The sealing hole 40 does not need to be provided when the plate-shaped base 31 and the plate-shaped lid 32 are joined in a vacuum. Thereby, the process can be simplified.
[0018]
The tuning-fork type piezoelectric vibrating reed 20 can be obtained by etching a piezoelectric crystal wafer and leaving the piezoelectric vibrating reed main body 25 and the frame 24 surrounding the piezoelectric vibrating reed main body 25. In the tuning-fork type piezoelectric vibrating reed 20, a metal film for an electrode is formed on the entire surface by sputtering or the like, and excitation electrodes are formed on the front and back surfaces and each side surface of the vibrating arms 22 and 23 by etching the metal film. The connection electrodes connected to the excitation electrodes are formed at the joints 28 and 29. The one mount electrode 34 is electrically connected to one external electrode 36 for mounting a substrate formed on the outer surface of the plate-like base 31 of the package 30. Further, the other mount electrode 35 is electrically connected to the other external electrode 37.
[0019]
The tuning fork type piezoelectric vibrator 10 having such a structure can be obtained by a manufacturing method including the following steps. 4 to 7 are views for explaining a method of manufacturing the tuning fork type piezoelectric vibrator 10. FIG. FIG. 4 is an explanatory diagram of the plate-like base 31 according to the embodiment of the present invention. FIG. 5 is an explanatory diagram of the plate-like lid 32 according to the embodiment of the present invention. 6 and 7 are process diagrams illustrating a method for manufacturing the tuning-fork type piezoelectric vibrator of the present invention.
[0020]
First, as shown in FIG. 3, a piezoelectric crystal such as quartz is etched using a photolithography technique, and a piezoelectric vibrating piece main body 25 having a base 11 and vibrating arms 22 and 23, and a piezoelectric vibrating piece main body 25 are formed. The tuning fork type piezoelectric vibrating piece 20 having the surrounding frame portion 24 is formed. Further, a metal film for an electrode (not shown) is formed on the entire surface of the tuning-fork type piezoelectric vibrating piece 20 by sputtering or the like. Further, the metal film is etched, excitation electrodes are formed on the front and back surfaces and the respective side surfaces of the vibrating arms 22 and 23 of the tuning-fork type piezoelectric vibrating piece 20, and the frame 24 is electrically connected to the excitation electrodes. A connection electrode is formed.
[0021]
On the other hand, external electrodes 36 and 37 are formed on the plate-like base 31 shown in FIG. 4 by plating, sputtering, or the like. Further, a metal paste is applied to a predetermined position on the upper surface of the plate-like base 31 by printing or the like, and is baked to form the mount electrodes 34 and 35. The mount electrodes 34 and 35 are electrically connected to external electrodes 36 and 37 via through holes (not shown) provided in the plate-like base 31. Further, the glass plate is cut into a predetermined size, and a plate-like lid 32 shown in FIG. 5 is obtained in advance.
[0022]
Next, in the first step of the manufacturing method according to the embodiment, as shown in step S1 of FIG. 6, a predetermined amount is set along the outer peripheral edge of the upper surface of the plate-shaped base 31 on which the mount electrodes 34 and 35 are provided. A low-melting glass is applied to a predetermined width and a predetermined thickness to form a low-melting glass layer 38. In the next second step, a low-melting glass layer 39 is formed by applying low-melting glass to a predetermined width and a predetermined thickness along the outer peripheral edge of one side surface of the plate-like lid 32 (step S2). . The low-melting glass layer 39 of the plate-shaped lid 32 is wider than the low-melting glass layer 38 of the plate-shaped base 31, and the plate-shaped base 31 and the plate-shaped lid 32 are joined as described later. At this time, a part of the low-melting glass layer 39 hangs or flows on the frame portion 24 of the tuning-fork type piezoelectric vibrating reed 20.
[0023]
The low melting point glass used in the first step and the second step is composed of a vitreous portion, a filler, and a solvent for converting the vitreous into a paste. As the vitreous material, lead oxide (PbO), boron oxide (B ₂ O ₅ ), zinc oxide (ZnO), silver oxide (AgO), phosphorus oxide (P ₂ O ₅ ), or the like can be used. Fillers are lead oxide (PbO), niobium oxide (Nb ₂ O ₃ ), calcium oxide (CaO), zirconium oxide (ZrO ₂ ), titanium oxide (TiO), silicon oxide (SiO ₂ ), magnesium oxide (MgO), Tin oxide (SnO ₂ ), aluminum oxide (Al ₂ O ₃ ), or the like can be used.
[0024]
In the third step, the conductive adhesive m is applied to the mount electrodes 34 and 35 of the plate-like base 31 (Step S3 in FIG. 6). Thereafter, the joining portions 28 and 29 of the frame portion 24 of the tuning fork type piezoelectric vibrating piece 20 are set on the conductive adhesive m (S4 in FIG. 6), and the conductive adhesive m is cured (step S5 in FIG. 6). ). That is, in the step of curing the conductive adhesive m, the plate-shaped base 31 on which the tuning-fork type piezoelectric vibrating reed 20 is disposed is placed in an annealing furnace, and the conductive adhesive m is heated and cured. In this step, degassing from the conductive adhesive m is sufficiently performed, and damage to the low-melting glass by the reducing gas at the time of joining the plate-shaped lid 32 can be recovered.
[0025]
In the fourth step, as shown in step S6 of FIG. 7, a low-melting glass layer 39 formed on the plate-shaped lid 32 is formed on a low-melting glass layer 38 formed on the upper surface of the plate-shaped base 31. Overlap. Furthermore, while pressing the plate-shaped base 31 and the plate-shaped lid 32 so as to approach each other, the two low-melting glass layers 38 and 39 are melted and joined by an annealing furnace to form the low-melting glass layer 33 ( Step S7). Thereby, the plate-shaped base 31 and the plate-shaped lid 32 are integrated via the low melting point glass layer 33.
[0026]
In the embodiment, when the joining position between the plate-shaped base 31 and the plate-shaped lid 32 is matched, the inner peripheral portion of the low-melting glass layer 39 on the plate-shaped lid 32 side has the tuning-fork type piezoelectric vibrating piece 20. To be hung on the outer periphery. However, when the low-melting glass layer 39 of the plate-shaped lid 32 is pressed against the plate-shaped base 31 and the plate-shaped lid 32 when the low-melting glass layers 38 and 39 are melt-bonded, the low-melting glass layer 39 is formed. The application width and the application amount may be such that a part of 39 flows to the upper part of the frame portion 24.
[0027]
By this bonding, the plate-like base 31 and the plate-like lid 32 are kept at a constant distance from each other by the low-melting glass layer 33 to form a box-shaped package 30. A vibration space is formed. The filler contained in the low-melting glass layer 33 generally has a diameter of several tens of μm, and the filler serves as a gap forming material. For this reason, the filler of the low-melting glass layer 33 covering a part of the upper surface of the frame portion 24 keeps the distance between the tuning-fork type piezoelectric vibrating piece 20 and the plate-like lid 32 constant, and the plate-like lid 32 becomes the tuning fork. The contact with the piezoelectric vibrating reed 20 is prevented.
[0028]
In the fifth step, the package 30 is vacuum sealed. In this vacuum sealing, first, a solder ball (gold (Au) / germanium (Ge) alloy) is set in the sealing hole 40. Then, in a vacuum atmosphere, a solder ball (metal ball) is irradiated with a laser to melt the solder ball, and the sealing hole 40 is sealed with the solder 41 (step S8 in FIG. 7). After that, laser is applied to the tip electrodes of the vibrating arms 22 and 23 through the plate-shaped lid 32 to perform laser trimming and frequency adjustment.
[0029]
According to the tuning fork type piezoelectric vibrator 10 obtained by the method of manufacturing the tuning fork type piezoelectric vibrator having such steps, the package 30 includes the plate-like base 31, the plate-like lid 32, and the low melting point glass layer 33. Therefore, the thickness can be reduced. Further, since the tuning-fork type piezoelectric vibrating reed 20 is not exposed from the package 30, there is no possibility of short-circuiting with other electronic components when mounted on the substrate, and the actual mounting area can be reduced. Further, in the tuning-fork type piezoelectric vibrator 10, since the interval between the mount electrodes 34 and 35 is wide, a short circuit between the electrodes due to the conductive adhesive m for mounting the tuning-fork type piezoelectric vibrating piece 20 can be avoided. According to the tuning-fork type piezoelectric vibrator 10 of the embodiment, since the tuning-fork type piezoelectric vibrating piece 20 is mounted in the package 30 via the frame portion 24 which is a non-vibrating portion, the influence of vibration leakage can be avoided, There is an advantage that electric characteristics are improved. Furthermore, in the tuning-fork type piezoelectric vibrator 10, since the frame portion 24 is fixed by the low melting point glass layer 33 over the entire periphery, the impact resistance can be improved.
[0030]
In the above embodiment, the case where the piezoelectric element is the tuning fork type piezoelectric vibrating piece 20 has been described, but the piezoelectric element may be an AT cut vibrating piece, an inverted mesa type AT cut vibrating piece or a SAW element. Further, in the above-described embodiment, the sealing hole 40 is provided in the plate-shaped base 31, but when the low-melting glass layers 38 and 39 are joined in a vacuum, the sealing hole 40 does not need to be provided. Further, in the above embodiment, the case where the low-melting glass, which is an inorganic adhesive, is used as the adhesive has been described. However, when the vacuum sealing is not performed, an organic adhesive may be used. Further, in the above embodiment, the case where the low melting point glass is used as the inorganic adhesive has been described, but the inorganic adhesive is not limited to the low melting point glass.
[0031]
Further, in the above-described embodiment, the case where a part of the low melting point glass layer 33 covers a part of the upper surface of the frame part 24 has been described, but the low melting point glass layer 33 does not have to be hooked on the frame part 24. In particular, when the piezoelectric element is an inverted-mesa type AT-cut vibrating reed, the vibrating portion is formed in the center concave portion of the vibrating reed. You may. Thereby, it is possible to further reduce the thickness.
[0032]
The tuning-fork type piezoelectric vibrating piece 20 according to the embodiment of the present invention can be used for various electronic devices such as a digital mobile phone, a portable information terminal, a personal computer, a television receiver, and a video device, a clock, and a device with a built-in clock. Can be used. Further, the above-described embodiments are preferred specific examples of the present invention, and various technically preferable limitations are added thereto, but the present invention is not limited to these embodiments.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a piezoelectric device according to an embodiment.
FIG. 2 is an enlarged sectional view of a part of FIG.
FIG. 3 is a sectional view taken along line AA of FIG. 1;
FIG. 4 is an explanatory diagram of a plate-like base according to the embodiment.
FIG. 5 is an explanatory diagram of a plate-like lid according to the embodiment.
FIG. 6 is a process chart of the method for manufacturing a piezoelectric device according to the embodiment.
FIG. 7 is a process chart of the manufacturing method continued from FIG. 6;
FIG. 8 is a plan view showing an example of a conventional tuning-fork type piezoelectric vibrator with a part thereof broken.
FIG. 9 is a longitudinal sectional view of an example of a conventional tuning-fork type piezoelectric vibrator.
[Explanation of symbols]
10: Piezoelectric device (tuning fork type piezoelectric vibrator), 20: Piezoelectric element (tuning fork type piezoelectric vibrating piece), 21: Base, 22, 23 ... Vibrating arm, 24 ... Frame , 25 ... piezoelectric vibrating piece main body, 28, 29 ... joining part, 30 ... package, 31 ... plate-like base, 32 ... plate-like lid, 33 ... adhesive (low Melting point glass layer), 34, 35... Mount part (mount electrode), 38, 39.

Claims (9)

A mounting step of mounting a piezoelectric element having an outer shape smaller than the plate base on the plate base,
Before or after this mounting step, an application step of applying an adhesive to the periphery of the plate-shaped lid and the plate-shaped base larger than the piezoelectric element,
A sealing step of joining the plate-shaped base and the plate-shaped lid via the adhesive, and forming a vibration space of the piezoelectric element with the plate-shaped base, the plate-shaped lid and the adhesive; ,
A method for manufacturing a piezoelectric device, comprising: The method for manufacturing a piezoelectric device according to claim 1,
The adhesive to the plate-like lid is applied to the application width such that a part of the adhesive hangs on or flows over a non-vibrating portion provided on a peripheral portion of the piezoelectric element in the sealing step. A method for manufacturing a piezoelectric device, comprising: The method for manufacturing a piezoelectric device according to claim 1,
The method for manufacturing a piezoelectric device, wherein the adhesive contains a filler. The method for manufacturing a piezoelectric device according to any one of claims 1 to 3,
The method for manufacturing a piezoelectric device, wherein the adhesive is an inorganic adhesive. A plate-like base,
A piezoelectric element whose outer shape is formed smaller than the plate-shaped base, and which is mounted on a mounting portion of the plate-shaped base;
A plate-shaped lid formed larger than the piezoelectric element and joined to the plate-shaped base via an adhesive;
A vibration space for the piezoelectric element formed by the plate-shaped lid, the plate-shaped base, and the adhesive;
A piezoelectric device comprising: The piezoelectric device according to claim 5,
The piezoelectric device according to claim 1, wherein a part of the adhesive covers at least a part of an upper surface of a non-vibration part provided on a peripheral part of the piezoelectric element. The piezoelectric device according to claim 5 or 6,
The piezoelectric device, wherein the adhesive contains a filler. The piezoelectric device according to any one of claims 5 to 7,
The said adhesive is an inorganic adhesive, The piezoelectric device characterized by the above-mentioned. The piezoelectric device according to any one of claims 5 to 8,
The piezoelectric element is
A piezoelectric vibrating reed body having a base and a vibrating arm protruding from the base,
A tuning fork type piezoelectric vibrating reed comprising a frame connected to the base and surrounding the piezoelectric vibrating reed main body,
A piezoelectric device, characterized in that:

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