JP2002171152A - Piezoelectric device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric device having an improved anti-shock property by making a piezoelectric vibrating element hardly bent inside a base and thereby preventing the element from being brought into contact with a cover even if a shock is applied from outside, and also to provide a method of sealing the same. SOLUTION: The piezoelectric device comprises the piezoelectric vibrating element 13, the base 12 for storing the piezoelectric vibrating element 13, and the metallic cover 14 for sealing the base wherein the piezoelectric vibrating element is stored, being bonded to an electrode section inside the base. The cover is formed with a convex part 21 projecting towards the piezoelectric vibrating element stored in the base.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric device comprising a base for accommodating a piezoelectric vibrating element and a lid for sealing the base, and an improvement in a method of manufacturing the same. .

[0002]

2. Description of the Related Art FIG. 16 is a partially cut perspective view showing a general piezoelectric vibrator as an example of a piezoelectric device.

The piezoelectric vibrator 1 has a box-shaped base 2 in which an internal space 2a for accommodating a plate-shaped piezoelectric vibrating element 3 is formed.
And a plate-shaped lid 4 joined to the base 2 so as to seal the internal space 2a. The piezoelectric vibrating element 3 is connected and fixed via a conductive adhesive 7, 7 to an electrode 6 disposed on a step portion having one end 3a integrally provided in the internal space 2a, and the other end 3b. It is a free end. The base 2 and the lid 4 are joined via a seam ring 5.

Here, the material of the piezoelectric vibrating element 3 is as follows.
For example, quartz is used, and ceramic such as alumina is used as a material of the base 2.

[0005] The lid 4 closes the base 2 accommodating the piezoelectric vibrating element 3 to seal the internal space 2a.
It is formed in a flat plate shape as shown in FIG. 17, and a metal such as Kovar is used. As a material of the seam ring 5, Kovar is used. As another sealing method, an EB (electron beam) method, or a silver brazing material, a soldering material, AuSn
Alternatively, there is a method of heating using nickel or the like.

That is, the piezoelectric vibrator 1 is, specifically,
It is manufactured by the steps shown in the flowchart of FIG.

In the figure, first, a base 2 is formed of a ceramic material such as alumina, and an electrode portion is formed by plating or the like so as to correspond to the piezoelectric vibrator 1 (ST1).

A piezoelectric vibration element 3 on which excitation electrodes and connection electrodes are formed in advance is mounted on the electrode portion of the base 2 via conductive adhesives 7 as shown in FIG. 16 (S).
T2). Next, the frequency is adjusted by applying a laser beam or the like to the excitation electrode on the surface of the piezoelectric vibration element 3 and adjusting the weight (ST3).

Next, the lid 4 is placed on the base 2 as shown in FIG. 16, and for example, a current is applied to the seam ring 5 via the lid 4 to melt the seam ring 5 and sealing is performed (ST).
4).

[0010] After the sealing is completed, marking for writing necessary characters and the like is performed on the surface of the lid 4 by printing or the like (ST5), and the marking is sent to an inspection step (ST6). And
When the pass is determined by the necessary inspection, the piezoelectric vibrator or the piezoelectric oscillator is completed.

[0011]

However, such a piezoelectric vibrator 1 has the following problems.

FIG. 19 is a schematic sectional view of the piezoelectric vibrator 1 of FIG. 16, and has the same structure as that of FIG. 16 except that the location of the seam ring 5 is shown larger than that of FIG. In the figure, the piezoelectric vibrator 1 is extremely miniaturized with miniaturization of various devices on which the piezoelectric vibrator 1 is mounted.
The height S1 of the piezoelectric vibrator 1 is 0.7 to 0.9 mm,
The distance S2 in the height direction of the internal space 2a is about 0.35 mm.

When the piezoelectric vibrating element 3 accommodated in the internal space 2a is joined to the electrode 6 via the conductive adhesive 7, the other end 3b, which is a free end, is shown as shown. In the interior space 2a, the gap at the one end 3a where the gap to the lid 4 is the smallest is set in the inner space 2a. Is about 0.10 mm.

In such an ultra-compact piezoelectric vibrator 1, when an external impact is applied, the impact is transmitted to the piezoelectric vibration element 3 as it is, and the piezoelectric vibration element 3 is bent in the direction of the arrow, and the internal space 2a is deflected. Since the distance S2 in the height direction is extremely small as described above, the other end 3b easily comes into contact with the back surface 4a of the lid 4, and the piezoelectric vibration element 3 itself or the conductive adhesive 7 is broken by an impact. In some cases.

When the piezoelectric vibrating element 3 bends in the direction of the arrow and the other end 3b contacts the back surface 4a of the lid 4, an electrode is formed on the other end 3b of the piezoelectric vibrating element 3. When it comes into contact with the back surface 4a of the metal lid 4, it is grounded via the seam ring 5, or when it comes into contact with the metal lid 4, and the piezoelectric vibrating element 3 is a tuning fork type vibrating piece, oscillation occurs. It may stop.

When the piezoelectric vibrating element 3 is largely bent in the direction of the arrow and the tip of the other end 3b contacts the back surface 4a of the cover 4, the chip may be broken by an impact.

It is an object of the present invention to solve the above-mentioned problems and to prevent the piezoelectric vibrating element from being easily bent in the base even when an external impact is applied, so that the piezoelectric vibrating element does not come into contact with the lid. Accordingly, an object of the present invention is to provide a piezoelectric device capable of improving impact resistance and a sealing method thereof.

[0018]

According to the first aspect of the present invention, there is provided a piezoelectric vibrating element, a base for accommodating the piezoelectric vibrating element, and the piezoelectric vibrating element being mounted on an electrode portion in the base. A piezoelectric device comprising: a lid for sealing the base in a bonded and housed state, wherein the lid has a projection protruding toward a piezoelectric vibration element housed in the base. Is achieved by

According to the first aspect of the present invention, a piezoelectric device to which the present invention is applied has at least a piezoelectric vibrating element housed in a base, and the base is sealed by a lid. .

Since the lid has a convex portion protruding toward the piezoelectric vibrating element housed in the base,
When an external impact is applied, even if the piezoelectric vibrating element bends to some extent, the piezoelectric vibrating element abuts on the convex portion, so that it does not bend further. Accordingly, the piezoelectric vibrating element is not broken beyond the limit of elastic deformation, and a large force is concentrated on the joint of the piezoelectric vibrating element, and the joint is not broken. Further, unlike the related art, it is possible to prevent the tip of the greatly bent piezoelectric vibrating element from colliding with the back surface of the lid and causing chipping.

Here, the convex portion is integrally or separately disposed at a position facing the piezoelectric vibrating element accommodated in the base of the lid, and is formed in a projecting shape or is formed with a bulging portion. It includes all forms of protrusions that have been formed.

According to a second aspect of the present invention, in the configuration of the first aspect, the convex portion is provided corresponding to a position closer to the joining portion than a tip portion of the piezoelectric vibration element, and the center of the convex portion is provided. A through hole is formed in the hole.

According to the structure of the second aspect, in addition to the function of the first aspect, by passing, for example, a laser beam through the through hole at the center of the projection, the tip of the piezoelectric vibrating element housed in the base can be raised. The laser beam can be irradiated to the electrode located at a position near the joint. Thus, after sealing the lid to the base, the frequency can be precisely adjusted in the sealed environment, and the frequency adjustment can be easily performed following the sealing operation.

[0024] Further, since the convex portion is provided corresponding to a position closer to the joint portion than the tip end portion of the piezoelectric vibrating element, when the piezoelectric vibrating element is bent, it is closer to the joint portion than the tip end. The region contacts the convex portion. As a result, the tip that is easily damaged can be effectively protected.

According to a third aspect of the present invention, in the configuration of the first or second aspect, an insulating film is formed on at least a region of the lid exposed in the base.

According to the third aspect of the present invention, even if the piezoelectric vibrating element is bent by an external impact and the piezoelectric vibrating element comes into contact with the convex portion, the inside of the base of the lid including the convex portion is formed. Since the insulating film is formed in a region exposed to the semiconductor device, a situation such as a short circuit can be avoided.

According to a fourth aspect of the present invention, in the configuration of the third aspect, the insulating film is formed of an elastic material.

According to the fourth aspect of the present invention, even if the piezoelectric vibrating element is bent by an external impact and the piezoelectric vibrating element comes into contact with the convex portion, the inside of the base of the lid including the convex portion is formed. Since the insulating film provided in the region exposed to the substrate has elasticity, it is possible to effectively prevent the piezoelectric vibrating element from being damaged.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the piezoelectric vibrating element has one end fixed to the base and the other end free. The side is housed in the base so as to be inclined in a direction away from the lid.

According to the fifth aspect of the present invention, the free end of the piezoelectric vibrating element is inclined in a direction away from the back surface of the lid, so that the distance between the fixed one end and the lid is minimized. Therefore, the whole can be configured to be small. Even if the free end side is slightly bent by an external impact, a large bending does not occur by contacting the convex portion.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the piezoelectric vibrating element is a rectangular quartz-crystal vibrating piece.

According to the structure of the sixth aspect, a rectangular quartz-crystal vibrating piece frequently used as a piezoelectric material can be suitably applied to the piezoelectric vibrating element.

The invention according to claim 7 is based on claims 1, 3, 4,
5. In any one of the configurations of 5, the piezoelectric vibration element
It is a tuning fork type quartz vibrating piece.

According to the structure of the seventh aspect, it is particularly effective that the tuning-fork type quartz vibrating reed in which the free end is forked and the electrodes having different polarities are exposed touches the lid and is short-circuited. Can be prevented.

According to an eighth aspect of the present invention, in the configuration of the seventh aspect, the convex portion is provided corresponding to a tip portion of the piezoelectric vibration element, and a through hole is formed at the center of the convex portion. It is characterized by the following.

According to a ninth aspect of the present invention, there is provided a piezoelectric vibrating element, a base for accommodating the piezoelectric vibrating element, and the piezoelectric vibrating element being joined to and accommodated in an electrode portion in the base. In a method for manufacturing a piezoelectric device comprising a lid for sealing the base in a state in which the piezoelectric vibrating element is accommodated in the base, and after the accommodating of the piezoelectric vibrating element, the lid is A first sealing for fixing to the base is performed, and after the first sealing, via a through hole of a convex portion provided to project toward the piezoelectric vibration element of the lid. Irradiating the electrode of the piezoelectric vibrating element with an electron beam or a light beam to adjust the frequency, and after this frequency adjustment, irradiating the metal material held in the through hole with an electron beam or a light beam, 2
This is achieved by a method of manufacturing a piezoelectric device that seals the piezoelectric device.

According to the ninth aspect of the present invention, the first sealing is performed under a predetermined condition, for example, in a vacuum or the like, and then the first sealing is performed through the through hole of the convex portion of the lid sealed and fixed to the base. Thus, the frequency can be adjusted by irradiating the electrodes of the piezoelectric vibrating element with an electron beam or a light beam, so that more precise frequency adjustment can be performed. In addition, following the frequency adjustment, the metal material held in the through hole of the projection is irradiated with an electron beam or a light beam to perform the second sealing, whereby the frequency adjustment and the second sealing are performed. The stopping operation can be performed as a series of operations, and the workability is improved.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic sectional view showing a piezoelectric vibrator corresponding to the first embodiment of the piezoelectric device of the present invention.

The piezoelectric vibrator 10 has a box-shaped base 12 in which an internal space 12a for accommodating a plate-shaped piezoelectric vibrating element 13 and a base 1 in which the internal space 12a is sealed.
2 is provided.

An electrode 16 is provided on the base 12, and one end 13a of the piezoelectric vibrating element 13 has an internal space 12a.
The other end 13b is a free end which is connected and fixed via a conductive adhesive 17 on an electrode 16 provided in the inside a. Thus, the driving voltage applied from the electrode 16 can vibrate at a predetermined frequency.

The base 12 and the lid 14 are connected to the seam ring 1
5 are joined. Here, the piezoelectric vibration element 13
As the piezoelectric material, for example, a single crystal substrate such as quartz, lithium tantalate, LBO, or a multilayer substrate such as ZnO / Si is used. In the present embodiment, a rectangular AT is used.
Cut quartz pieces are used. Seam ring 15
For example, Kovar, and its thickness is, for example, 150 μm.
m. As a material of the base 12, for example, a ceramic such as alumina is fired into a predetermined shape as shown and used.

The lid 14 is formed of a metal material, and is preferably formed of, for example, Kovar or 42 alloy. Alternatively, ceramic such as alumina having a linear expansion coefficient close to that of the base 12 may be used. However, in this case, the sealing method is Au-Sn sealing and low melting point glass sealing. In this embodiment, for example, an example in which the Kovar lid 14 is sealed with a seam ring will be described.

The base 12 and the lid 14 are connected to the seam ring 1
5, for example, a metal coating layer is provided on a bonding surface that is an upper end surface of the base 12. This metal coating layer is formed by laminating a plurality of types of metals in layers, for example,
A plurality of metal layers such as a tungsten layer, a nickel plating layer, and a gold plating layer are sequentially provided from below, the seam ring 15 is fixed with a silver braze, and the Kovar lid 14 is placed. Seam ring 15 and lid 14
The sealing can be performed by melting the nickel and gold plated on the seam ring 15 and the lid 14 by Joule heat generated at the joint portion between the metal and the metal. Alternatively, sealing can be performed by irradiating a light beam or an electron beam to the periphery of the lid 14.

Preferably, the piezoelectric vibration element 13 is
The other end 13b is inclined in a direction in which the other end 13b moves away from the lid 14, that is, in FIG. Are bonded and fixed by a conductive adhesive 17. This is one end 1 of the piezoelectric vibrating element 13 which is long in one direction.
A state in which the other end 13b, which is a free end, does not touch the inner bottom surface of the base 12 by controlling the viscosity and the curing time of the conductive adhesive 17 by fixing the cantilever type 3a, thereby controlling the viscosity. It is fixed by.

FIG. 2 is a schematic perspective view of the lid 14.

As described above, the lid 14 is preferably formed of a metal material such as Kovar, and
A projection 21 is provided on a surface of the base 12 that is exposed to the internal space 12a when the base 12 is placed and sealed.

The protruding portion 21 is provided on the metal lid 14 as shown in FIG.
For example, when a jig such as a punch having a profitable tip is strongly applied to the upper surface of, a convex portion protruding from the lower surface is formed. The convex portion 21 is, as shown in FIG.
4, it may be formed integrally, may be provided separately,
It includes all types of protrusions formed as protrusions or bulges.

Preferably, as shown in FIG. 1, a through hole 21a is opened at the center of the projection 21.

FIG. 3 shows the lid 14 of the piezoelectric vibrator 10 of FIG.
FIG. 3 is a schematic plan view in which the inside of a base 12 has been exposed by removing. As shown in the drawing, the position of the convex portion 21 when the lid 14 is put on the base 12 is located at one end 13 a which is a joint portion rather than the tip end of the piezoelectric vibrating element 13, and is preferably excited. It is provided near the tip of the electrode 13c, and the position of the through hole 21a is also near the tip of the excitation electrode 13c.

The present embodiment is configured as described above, and the cover 14 of the piezoelectric vibrator 10 is formed with a convex portion 21 protruding toward the piezoelectric vibration element 13 accommodated in the base 12. . Therefore, for example, when the piezoelectric vibrator 10 is mounted on a predetermined mounting device or the like and a user drops the device or an external shock is applied to the piezoelectric vibrator 10, the impact Is applied to the built-in piezoelectric vibration element 13. As a result, even if the piezoelectric vibrating element 13 bends to some extent in the direction of arrow A in FIG. As a matter of course, unlike the conventional case, the tip of the greatly bent piezoelectric vibrating element collides with the back surface of the lid to cause chipping, thereby effectively preventing the vibration performance from being adversely affected.

Further, the piezoelectric vibrating element 13 is damaged by being greatly bent beyond the limit of the elastic deformation, or a large force is concentrated on the conductive adhesive 17 at the joint portion of the piezoelectric vibrating element 13 so that the cured adhesive is hardened. Since the agent does not break,
The durability is improved.

When the through-hole 21a is formed in the projection 21, as described later, when adjusting the frequency of the piezoelectric vibrating element 13, a light beam such as an electron beam or a laser is allowed to pass therethrough. The frequency can be adjusted after sealing the lid 14 to the base.

FIG. 4 is a partial cross-sectional view showing a lid 34 which is a main part of a piezoelectric vibrator 30 as a second embodiment of the piezoelectric device.
This is shown in FIGS.

In the figure, the piezoelectric vibrator 30 has a cover 3
Only the configuration 4 is different from that of the first embodiment. In FIGS. 6 and 8, the portions denoted by the same reference numerals as those of the piezoelectric vibrator 10 have the same configuration, and thus the overlapping description will be omitted, and the difference will be omitted. The explanation will focus on the points.

As shown in FIG. 4, the lid 34 is
It has a portion of the main body 38 and an insulating film 32 formed on the main body 38. That is, the main body 38 of the lid 34 is formed of the same material as that of the first embodiment. Body 38
6, at least the inner space 12a of the base 12
The insulating film 32 is formed in a region exposed to the substrate. The insulating film 32 is a film having at least an electrical insulating action, and is formed, for example, of SiO ₂ as an oxide film. Alternatively, more preferably, the insulating film 32
In order to have an electrical insulation effect and a buffering effect to reduce impact, it may be formed of a material having electrical insulation and elasticity, for example, silicone.

Further, a convex portion is formed on the lid 34 similarly to the first embodiment. As shown in FIG. 4, a through hole 33 is formed at the center of the convex portion 31. The inner diameter of the through hole 33 is, as shown in FIG.
The inclined surface 37 gradually decreases in diameter toward the bottom, and the hole diameter 33a at the lower end is the smallest.

Since the present embodiment is configured as described above, not only all the functions and effects of the first embodiment are exhibited, but also the following advantages are obtained.

This advantage will be described together with the description of the method of manufacturing the piezoelectric vibrator 30. FIG. 5 shows the piezoelectric vibrator 30.
This shows the characteristic steps in the manufacturing method described above.

In the figure, in step 10, the excitation electrodes and the connection electrodes are formed on a quartz piece cut from a predetermined quartz wafer by vapor deposition or the like in the same manner as in the prior art.
Is formed (ST10).

In parallel with this, the base 12 is formed of a ceramic material such as alumina, and the piezoelectric vibrating element 13 is formed.
The electrode portion is formed by, for example, plating or the like.

Next, a piezoelectric vibrating element 13 on which electrodes and connection electrodes are formed in advance is mounted on the electrode portion 16 of the base 12 via conductive adhesives 17, 17 (ST1).
2).

Next, a first frequency adjustment is performed (S
T13). The first frequency adjustment is performed by applying a drive voltage to the piezoelectric vibration element 13 and monitoring the vibration frequency before the lid 14 is joined in a state where the piezoelectric vibration element 13 is mounted on the base 12. The frequency can be adjusted by increasing the material of the excitation electrode 13c (see FIG. 3) of the piezoelectric vibrating element by vapor deposition to increase the film thickness and adjusting the vibration frequency of the piezoelectric vibrating element 13 to be low by the mass increasing method. The excitation electrode 13c may be irradiated with a light beam such as a laser or an electron beam (ion beam) or the like to evaporate the electrode material from the surface and adjust the vibration frequency to a high value.

After step 13, the first sealing of step ST14 is performed. The first sealing is performed, for example, by covering the base 12 with a lid 34 made of Kovar covered with nickel plating and melting the nickel and gold plated on the seam ring 15 in a vacuum, for example. Is joined to the base 12 to seal the internal space 12a of the base 12. Here, the sealing is performed by a sealing method in which nickel and gold on the seam ring 15 are melted, but other sealing methods may be used, and sealing using a low-melting glass, An—Sn, or the like as a sealing material is performed. It may be a method.

Here, in ST14, the seam ring 15
Since nickel and gold plated on the substrate are melted, heat is generated, and the heat evaporates components of the conductive adhesive 17 and the like, and generates outgas. When this gas component adheres to the piezoelectric vibrating element 13, a deviation occurs in the vibration frequency.
Further, when the sealing step is performed in a vacuum atmosphere, if the degree of vacuum changes after sealing, the CI (crystal impedance) value of the piezoelectric vibrator 30 shifts.

Then, after the first sealing, the lid 3 is continuously placed in the same environment, for example, in a vacuum.
As shown in FIG. 6, a light beam such as a laser beam, an electron beam (ion beam), or the like (hereinafter, referred to as a “beam”) is passed through the through hole 33 of the projection 31 of FIG. The second frequency adjustment is performed by irradiation.

Here, since the convex portion 31 is formed at the same position as the position shown in FIG. 3, the beam B 1 passing through the through hole 33 receives the beam B 1 of the piezoelectric vibrating element 13 mounted in the base 12. By hitting the surface of the excitation electrode 13c and evaporating the electrode film component at the irradiated location, the piezoelectric vibration element 13
Is adjusted to a higher frequency, and the frequency is adjusted more precisely (ST15).

Next, as shown in FIG. 7 and FIG.
In the through-hole 33 of the convex portion 31 of FIG. 4, a small metal ball 35 is preferably disposed as a sealing metal material from the top in addition to a disk-shaped, column-shaped, prism-shaped, or the like, as shown in FIG.
In the same atmosphere as that of No. 15, the second sealing is performed using the beam generating means 36 as it is (ST16).

In this case, as shown in a partially enlarged view of FIG. 7, the metal sphere 35 has an outer diameter larger than the opening 33a on the base 12 side of the through hole 33 of the projection 31 and smaller than the outer opening 33b. Use a metal sphere. Also, the metal ball 35
Can be gold tin (Au-Sn).

As a result, the metal ball 35 is rolled by being supplied by using a predetermined jig or the like, so that the metal ball 35 is rolled as shown in FIG.
As shown in FIG. 8, since it easily enters the through hole 33 of the convex portion 31 and is held on the inclined surface 37, as shown in FIG. Accordingly, the metal ball 35 is irradiated with the beam B2 using the beam generating means 36 as it is, and the metal ball 35 is melted, whereby the through-hole 33 can be easily closed.

Next, inspection is performed in the same manner as in the conventional ST6 described with reference to FIG. 18, and the manufacture of the piezoelectric vibrator 30 is completed (ST17).

If necessary, marking may be performed in the step before ST17 in the same manner as in the prior art.

As described above, according to the above-described manufacturing method, the first sealing is performed under a condition such as a vacuum (ST14), and subsequently, through the through-hole 33 of the convex portion 31 of the lid 34. Since the frequency can be adjusted by irradiating the electrode 13c of the piezoelectric vibration element 13 with a beam (ST15), the first sealing step (ST13) is performed after the first frequency adjustment (ST13).
Even when the vibration frequency of the piezoelectric vibrating element 13 shifts due to the step 14), more precise frequency adjustment can be performed. In addition, following the second frequency adjustment, the metal ball 3 held in the through hole 33 of the projection 31
5 is irradiated with a beam to perform a second sealing (ST16).
Thus, the frequency adjustment and the second sealing operation can be performed as a series of operations, and the workability is good, and more precise frequency performance can be provided as compared with the conventional case.

It is needless to say that such a process can be performed in the piezoelectric vibrator 10 described with reference to FIG.

FIG. 9 shows a modification of the structure of the projection provided on the lid. FIG. 9A shows a first modification of the projection. In the figure, a through hole 44 of a convex portion 41 has an inclined surface 42 and a horizontal bottom portion 43 following the inclined surface 42. The upper side of the inclined surface 42 is a relatively large upper opening 44a.
Is formed, and a lower opening 44b which is relatively small and is opened is formed at the center of the bottom portion 43.

As a result, the convex portion 41 has a spring means composed of the inclined surface 42 and the bottom portion 43. When an external impact is applied to the piezoelectric vibrating element 13, the convex portion 41 bends. , The convex portion 41 is deformed,
The impact can be absorbed by the spring elasticity. For this reason, the situation where the piezoelectric vibrating element 13 comes into contact with the convex portion 41 and is damaged is more reliably prevented.

Further, the configuration for imparting elasticity to the convex portion is not limited to the configuration shown in FIG. 9A, but may be another configuration integral with the lid 34, or the convex portion may be formed separately from the lid 34. May be formed of the above elastic material.

FIG. 9B shows a second modification of the projection provided on the lid, and shows another configuration of the through hole formed in the projection. That is, in this case, FIG.
The through hole 45 provided in the convex portion 31 described in the above section is a long hole, and a metal ball 35 is disposed at one end of the long hole.

Thus, in the case of the frequency adjustment described with reference to FIG.
The beam is allowed to pass through 5a, and then, at the time of the second sealing in FIG. 8, the beam is relatively moved in the direction of the arrow, thereby melting the metal ball 35 and closing the through hole 45. To do. Therefore, the operation from the second frequency adjustment to the second sealing is performed by a simple operation of merely changing the irradiation position of the beam, so that the operation efficiency is further improved.

FIGS. 10 to 12 are views for explaining a piezoelectric vibrator 50 as a third embodiment of the piezoelectric device.

In the figure, the portions denoted by the same reference numerals as those in the first embodiment or the second embodiment have the same configuration in the piezoelectric vibrator 50, and therefore, the duplicated description will be omitted.
The following description focuses on the differences.

FIG. 10 is a plan view of the lid 54 of the piezoelectric vibrator 50 shown in FIG. The piezoelectric vibrator 50 accommodates a tuning fork type piezoelectric vibration element 53, and correspondingly,
The cover 54 has two convex portions 51, 51.

The lid 54 is made of the same material as the lid 14 in the first embodiment, and has an insulating film 32 in a region exposed in the base. Each convex part 51, 5
1 are through holes 33, 33, as shown in FIG.
And has the same configuration as the protrusions 31 of the second embodiment, but is different in the position and the number formed on the lid 54.

As shown in FIG. 12, in the base 12,
The piezoelectric vibrating element 53 is housed therein. The piezoelectric vibrating element 53 has two vibrating arms 55 and 56 on a free end side, which is a forked bifurcated tip side.
Vibrate in the directions indicated by the arrows in FIG.

For this reason, the convex portions 51, 51 are provided corresponding to the positions shown in FIG. That is, in the piezoelectric vibrating element 53, the free end side is provided with two vibrating arms 55 and 56.
The projections 51, 51 to be brought into contact with each other when they are bent by receiving an external impact are also provided with the respective vibrating arms 5.
5 and 56, respectively.

The configuration other than the above is almost the same as the first and second embodiments. Therefore, in this embodiment, even when the tuning fork type piezoelectric vibrating element 53 is used, the first
The same operational effects as those of the second embodiment can be exhibited.

FIGS. 13 and 14 show a fourth example of the piezoelectric device.
6 is a diagram for explaining a piezoelectric vibrator 60 as an embodiment.

In the figure, the portions denoted by the same reference numerals as those of the piezoelectric vibrator 10 of the first embodiment have the same configuration in the piezoelectric vibrator 60, and therefore the duplicated description will be omitted, and the differences will be mainly described. explain.

In FIG. 13, the structure of the piezoelectric vibrating element 63 is partially different from that of the piezoelectric vibrator 10 of the first embodiment. In the piezoelectric vibration element 63, in the figure,
At least the surface of the electrode 13c facing the lid 14 is covered with an insulating film 13d.

The insulating film 13d is a film having at least an electrical insulating action.
It is formed of SiO ₂ . Alternatively, more preferably, the insulating film 13d may be formed of a material having electrical insulation and elasticity, for example, silicone or the like, in order to have an electrical insulating action and a buffer action to reduce an impact.

The present embodiment is configured as described above. In addition to the same functions and effects as those of the first embodiment, the piezoelectric vibrating element 13 is bent by an external impact, and
In this case, since the surface of the piezoelectric vibrating element 13 facing the lid 14 is covered with the above-described insulating film 13 d, the insulating film 13 d comes into contact with the projection 21. For this reason, there is no possibility of conduction with the metal lid 14 to cause a short circuit or the like.

FIG. 15 is a view for explaining a piezoelectric oscillator 70 as a fifth embodiment of the piezoelectric device.

In the figure, the portions denoted by the same reference numerals as those of the piezoelectric vibrator 10 of the first embodiment have the same configuration, and therefore, the duplicate description will be omitted, and the differences will be mainly described.

FIG. 15 is a schematic sectional view of the piezoelectric oscillator 70. In FIG.
Unlike the base 12 of FIG. 1, a step portion is provided inside to provide a lower internal space 72a. The integrated circuit 71 is mounted on the conductive pattern formed on the upper surface of the base 12, housed in the internal space 72 a, and connected to the electrode 73. As a result, a predetermined drive voltage is applied to the piezoelectric vibration element 13 to cause it to vibrate, and its output is input to the integrated circuit 71, thereby extracting a signal of a predetermined frequency.

In this piezoelectric oscillator 70, the lid 14
The projection 21 is formed on the surface facing the piezoelectric vibration element 13.

The present embodiment is configured as described above, and the cover 14 of the piezoelectric oscillator 70 is formed with the protrusion 21 projecting toward the piezoelectric vibration element 13 housed in the base 12. For this reason, for example, when the piezoelectric oscillator 70 is mounted on a predetermined mounting device or the like and a user drops the device or an external shock is applied to the piezoelectric oscillator 70, the shock is Applied to the built-in piezoelectric vibration element 13. Accordingly, even if the piezoelectric vibrating element 13 is flexed to some extent in the direction of arrow A in FIG. 15, the inner side of the tip of the piezoelectric vibrating element 13 is slightly in contact with the convex portion 21 on the inner surface of the lid 14. As a matter of course, unlike the conventional case, the tip of the greatly bent piezoelectric vibrating element collides with the back surface of the lid to cause chipping, thereby effectively preventing the vibration performance from being adversely affected.

Further, the piezoelectric vibrating element 13 is damaged by being largely bent beyond the limit of elastic deformation, or a large force is concentrated on the conductive adhesive 17 at the joint portion of the piezoelectric vibrating element 13 so that the cured adhesive is hardened. Since the agent does not break,
The durability is improved.

When the through hole 21a is formed in the projection 21, as described above, when adjusting the frequency of the piezoelectric vibrating element 13, a light beam such as an electron beam or a laser is allowed to pass therethrough. The frequency can be adjusted after sealing the lid 14 to the base.

[0099]

As described above, according to the present invention, even when an external impact is applied, the piezoelectric vibrating element hardly bends in the base and does not come into contact with the lid. Accordingly, it is possible to provide a piezoelectric device capable of improving impact resistance and a method for manufacturing the same.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a piezoelectric vibrator according to a first embodiment of the piezoelectric device of the present invention.

FIG. 2 is a schematic perspective view of a lid of the piezoelectric vibrator of FIG.

FIG. 3 is a schematic plan view of the piezoelectric vibrator of FIG. 1 with a lid removed.

FIG. 4 is a schematic sectional view of a main part of a lid of the piezoelectric vibrator of FIG. 1;

FIG. 5 is a flowchart showing a method for manufacturing a piezoelectric vibrator which is an embodiment of the piezoelectric device of the present invention.

FIG. 6 is a schematic sectional view showing a piezoelectric vibrator according to a second embodiment of the piezoelectric device of the present invention.

FIG. 7 is a schematic sectional view of a main part of a lid of the piezoelectric vibrator of FIG. 6;

FIG. 8 is a schematic sectional view showing a piezoelectric vibrator according to a second embodiment of the piezoelectric device of the present invention.

9A and 9B show modified examples of the lid of the piezoelectric vibrator shown in FIGS. 6 and 8, wherein FIG. 9A shows a first modified example, and FIG. 9B is a schematic sectional view of a main part of the lid, and FIG. FIG. 9 is a schematic plan view showing a modified example of the first embodiment, and showing the shape of a through hole of a convex portion of a lid.

FIG. 10 is a schematic plan view showing a lid of a piezoelectric vibrator according to a third embodiment of the piezoelectric device of the present invention.

FIG. 11 is a sectional view taken along line CC of FIG. 10;

FIG. 12 is a schematic plan view of a piezoelectric device according to a third embodiment of the present invention, in which a lid of a piezoelectric vibrator is removed.

FIG. 13 is a schematic sectional view showing a piezoelectric vibrator according to a fourth embodiment of the piezoelectric device of the present invention.

FIG. 14 is a schematic cross-sectional view of a main part of the piezoelectric vibration element of FIG.

FIG. 15 is a schematic sectional view showing a piezoelectric oscillator according to a fifth embodiment of the piezoelectric device of the present invention.

FIG. 16 is a schematic perspective view of a conventional piezoelectric device.

FIG. 17 is a schematic perspective view of a lid of the piezoelectric device of FIG. 16;

FIG. 18 is a flowchart illustrating an outline of a manufacturing process of the piezoelectric device in FIG. 16;

FIG. 19 is a schematic sectional view of the piezoelectric device of FIG. 16;

[Explanation of symbols]

 10, 30, 50, 60 Piezoelectric vibrator 13, 53, 63 Piezoelectric vibrating element 12 Base (housing part) 12a Internal space 16 Electrode 17 Conductive adhesive 21, 31, 41, 51 Convex part

Claims (9)

[Claims] 1. A piezoelectric vibrating element, a base for accommodating the piezoelectric vibrating element, and a lid for sealing the base in a state where the piezoelectric vibrating element is housed by being joined to an electrode portion in the base. The piezoelectric device according to claim 1, wherein the lid has a protrusion protruding toward the piezoelectric vibrating element housed in the base. 2. The method according to claim 1, wherein the protrusion is provided at a position closer to the joint than a tip end of the piezoelectric vibration element, and a through hole is formed at the center of the protrusion. The piezoelectric device according to claim 1, wherein: 3. The piezoelectric device according to claim 1, wherein an insulating film is formed on at least a region of the lid that is exposed in the base. 4. The piezoelectric device according to claim 3, wherein said insulating film is formed of an elastic material. 5. The piezoelectric vibrating element has one end fixed to the base and the other end free. The other end is inclined in a direction away from the lid and is housed in the base. The piezoelectric device according to any one of claims 1 to 4, wherein 6. The piezoelectric device according to claim 1, wherein the piezoelectric vibrating element is a rectangular crystal vibrating piece. 7. The piezoelectric device according to claim 1, wherein the piezoelectric vibrating element is a tuning-fork type quartz vibrating piece. 8. The method according to claim 7, wherein the protrusion is provided corresponding to a tip of the piezoelectric vibration element, and a through hole is formed at a center of the protrusion. Piezo device. 9. A piezoelectric vibrating element, a base for accommodating the piezoelectric vibrating element, and a lid for hermetically sealing the base in a state where the piezoelectric vibrating element is housed by being joined to an electrode portion in the base. In the method for manufacturing a piezoelectric device, comprising: accommodating the piezoelectric vibrating element in the base; and performing first sealing for fixing the lid to the base after accommodating the piezoelectric vibrating element. After the first sealing, an electron beam or a light beam is applied to an electrode of the piezoelectric vibrating element via a through hole of a convex portion provided to protrude toward the piezoelectric vibrating element of the lid. The second sealing is performed by irradiating the metal material held in the through hole with an electron beam or a light beam after the frequency adjustment. Device manufacturing method.