JPH11136077A - Piezoelectric vibrator - Google Patents

Abstract

(57) [Problem] To provide a piezoelectric vibrator that is reduced in size and thickness and that electrical conduction to a vibrating element is reliably performed. SOLUTION: In a piezoelectric vibrator constituted by sandwiching a support 3 between a first plate 1 on which a first conductor 2 is formed and a second plate 4, a side surface portion on which an external electrode 9 of a package is formed. The contact area between the external electrode 9 and the first conductor 2 is configured by configuring the side surface of the support 3 located at the side of the first plate 1 and the second plate 4 to be inside. And the electrical conduction from the excitation electrode 6 to the external electrode 9 can be reliably performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a series resonance device, and more particularly to a piezoelectric vibrator provided with a vibrating element made of a piezoelectric material.

[0002]

2. Description of the Related Art When an appropriate electrode pattern is formed on a piezoelectric substrate made of quartz, LiTaO ₃ , LiNbO _3, etc., and an AC electric field is applied to the electrode, the piezoelectric generates a stress having a frequency equal to the applied electric field. In addition, when the frequency of the applied electric field matches the natural frequency of the piezoelectric body, resonance occurs and strong vibration is obtained. Since the piezoelectric vibrator based on such a principle has a small size and high performance, it is widely used as an oscillation circuit or a filter of a communication device or the like.

Conventionally, a piezoelectric vibrator has been disclosed in Japanese Patent Publication No. 3-7040.
No. 7 is known. FIG. 10 shows a conventional piezoelectric vibrator.

In FIG. 10, a piezoelectric vibrator 21 includes a vibrating element 22 and a sealing cap 23 made of ceramic or the like.
Is mounted on a mounting substrate 24 made of ceramic or the like. The vibrating element 22 forms electrode patterns 26 and 26 ′ each including a T-shaped electrode portion 26 a and a connection portion 26 b on opposing main surfaces that are front and rear surfaces of the piezoelectric substrate 25, respectively.
The piezoelectric substrate 25 has a pair of end conductors 27 and 27 ', which are a pair of lead conductor layers, formed in a thick film at one end, and a pair of end electrodes which are a pair of lead conductor layers at the other end. 28 and 2
After forming the thick film 8 ', the end electrodes 27, 27' and 28 '
And 28 ', respectively, and conductor layers 29 and 30 forming a lead conductor layer are applied.

On the other hand, a pair of conductor layers 31 and 32 facing the end electrodes 27 ′ and 28 ′ are formed on the upper surface of a mounting substrate 24 larger than the vibration element 22 for mounting the sealing cap 23. The end electrode 27 'and the conductor layer 31 and the end electrode 28' and the conductor layer 32 are electrically connected.

[0006]

However, in the above-described piezoelectric vibrator, since a concave portion must be formed in the sealing cap 23, the sealing cap 23 must be made thick, and the There is a problem that it is very difficult to reduce the size and thickness. Further, a step of forming a concave portion in the sealing cap 23 is required, which is a factor of deteriorating cost performance.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a piezoelectric vibrator which can be reduced in size and thickness and is advantageous in cost performance.

[0008]

According to the present invention, there is provided a piezoelectric vibrator comprising a first plate, a second plate, and a support, wherein the first plate and the second plate are provided. Each of the side plates is formed of a flat plate, sandwiches a support between the first plate and the second plate, and the side portion of the support located on the side portion forming the external electrode of the package includes the first side. It is configured such that it is formed inside the side surface of the plate and the side surface of the second plate to increase the connection area between the first conductor and the external electrode. In addition, a third conductor is formed on the second plate, and electrically connected to the excitation electrode of the vibration element via the second conductor on the inner side of the third conductor. The surface end of the conductor is electrically connected to an external electrode.

Thus, a flat plate without any special processing is used as the package, and the contact area between the first and third conductors and the external electrode can be increased. Electrical conduction from the electrode to the external electrode can be reliably performed, and a package excellent in cost performance can be manufactured. Furthermore,
The electrodes of the internal vibration element can be easily led out to the outside, and the size and thickness of the piezoelectric vibrator can be reduced.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention comprises a first plate having at least one surface on which at least two or more first conductors are formed from an intermediate portion to a surface end portion; A support having a space inside, a vibration element having excitation electrodes formed on the front and back surfaces, a second plate, and external electrodes,
The vibrating element is in a package formed by the first plate, the support, and the second plate, is fixed by a second conductor, and is connected to the excitation electrode via the second conductor. And the first conductor are electrically conducted, the first conductor is led out of the package and is electrically conducted to the external electrode, and the first plate is electrically connected to the second plate.
In each of the piezoelectric vibrators each having a flat plate, and having the support between the first plate and the second plate,
A piezoelectric member configured such that a side portion of the support positioned on a side portion forming the external electrode of the package is located inside a side portion of the first plate and a side portion of the second plate. The vibrator uses a flat plate that has not been subjected to special processing as a package, and can provide a large contact area between the first conductor and the external electrode. It has an effect that electrical conduction can be reliably performed.

According to a second aspect of the present invention, at least two or more third conductors are formed on at least one of the surfaces of the second plate connected to the support, from the inside to the end of the surface. The inside of the third conductor is electrically connected to the excitation electrode via the second conductor, and the first conductor and the third conductor are connected to an external electrode on a side surface of the package. 2. The piezoelectric vibrator according to claim 1, wherein the piezoelectric vibrator is electrically connected to the external electrode, and has an effect that electrical conduction from the excitation electrode to the external electrode can be performed more reliably.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. FIG. 1 is an exploded perspective view of a basic configuration of a piezoelectric vibrator common to all embodiments of the present invention. 1 is a first plate, 2 is a first conductor formed on the first plate 1, 3 is a support, 4 is a second plate, 5 is a vibration element, and 6 is a front and back surface of the vibration element 5. This is the excitation electrode formed in FIG.

(Embodiment 1) FIG. 2 shows Embodiment 1 of the present invention. In FIG. 2, a first conductor 2 is formed from an intermediate portion of one surface to an end of the surface. The support 3 is sandwiched between a first plate 1 made of a flat plate and a second plate 4 made of a flat plate. Each of the first plate 1, the support 3 and the second plate 4 is made of one of glass and resin film. The first conductor 2 is formed by a thick film printing by screen printing or the like, a metal thin film by metal evaporation or sputtering, or a copper foil.

The surface of the first plate 1 facing the support 3 is the surface on which the first conductor 2 is formed. Further, the first plate 1 and the support 3 and the second plate 4 and the support 3 are bonded through an adhesive layer 8. The adhesive layer 8 is mainly composed of a thermosetting resin or an ultraviolet curable resin. In any case, it is important that the resin can be easily cured. Further, it is desirable to perform the curing of the resin while pressurizing the whole. The first plate 1, the support 3 and the second plate 4 form a package of the piezoelectric vibrator.

Here, the vibrating element 5 is accommodated in a space formed in the support 3, and the excitation electrodes 6 formed on the front and back surfaces are formed by the second conductor 7 by the first conductor 1. The vibration element 5 is fixed to a space in a package formed by the first plate 1, the support 3, and the second plate 4 by the second conductor 7. Further, the vibrating element 5 requires a space in the peripheral portion and the side surface portion of the excitation electrode 6, and when the space is not provided and the package is in contact with the package, the vibration characteristics are significantly deteriorated. As a solution to the problem, for example, a first plate 1 and a second plate
The surface of each plate 4 facing the vibrating element 5 is formed in such a manner that a portion larger than the size of the excitation electrode 6 is formed into a concave shape.

However, according to the embodiment of the present invention, the first
The space between the first plate 1 and the vibrating element 5 can be created by the presence of the conductor 2, and the second conductor 7 can be formed between the first conductor 2 and the excitation electrode 6. The space between the first plate 1 and the vibrating element 5 can be made wider by intervening. With this configuration, the first plate 1 can be a flat plate.

Further, since the thickness of the support 3 is at least equal to or greater than the vibration element 5 and the second conductor 7 is formed up to the surface of the vibration element 5 facing the second plate 4, A space can be formed between the second plate 4 and the vibrating element 5 without forming a concave portion on the second plate 4 and as a flat plate.

The side surface of the support 3 located on the side surface forming the external electrodes of the package is the first plate 1.
Since the outer dimensions are configured to be smaller than the side portions of the first and second plates 4, the contact area between the external electrode 9 and the first conductor 2 can be increased, so that the excitation Electrical conduction from the electrode 6 to the external electrode 9 can be reliably performed.

(Embodiment 2) FIG. 3 shows Embodiment 2 of the present invention. The same components as those of Embodiment 1 shown in FIG. Is omitted.

In FIG. 3, the support 10 is made of only an adhesive, and the support 10 made of the adhesive also has outer dimensions so as to be inside the side surfaces of the first plate 1 and the second plate 4. Is configured to be small. This adhesive is mainly composed of a thermosetting resin or an ultraviolet curable resin. In any case, it is important that the resin can be easily cured. However, in this case, the first plate 1
From the second plate 4 to the second plate 4 without applying pressure. If hardening while applying pressure, the second plate 4 and the vibration element 5 come into contact with each other, resulting in deterioration of vibration characteristics.

(Embodiment 3) FIG. 4 shows Embodiment 3 of the present invention, and the same components as those of Embodiment 1 shown in FIG. Is omitted.

In FIG. 4, the second conductor 11 is composed of a bump and a conductive adhesive. The bumps of the second conductor 11 are made of Au or solder. In the first embodiment, it has been described that a space is required between the vibration element 5 and the first plate 1.
The required space can be secured. In addition, electrical conduction between the excitation electrode 6 and the first conductor 2 can be stabilized.

(Embodiment 4) FIG. 5 shows Embodiment 4 of the present invention. The same components as those of Embodiment 1 shown in FIG. Is omitted.

FIG. 5 has a feature obtained by combining the second and third embodiments. The support 10 is composed of only an adhesive, and the second conductor 11 is composed of a bump and a conductive adhesive. ing. In this configuration, since a space can be reliably formed between the vibration element 5 and the first plate 1 by using the bumps, the deterioration of vibration characteristics due to the contact between the vibration element 5 and the package does not occur. Then, the first plate 1 and the second plate
Plate 4 can be easily bonded. At this time, as in the second embodiment, the resin must be cured without applying pressure between the first plate 1 and the second plate 4. If hardening while applying pressure, the second plate 4 and the vibration element 5 come into contact with each other, resulting in deterioration of vibration characteristics.

(Fifth Embodiment) FIG. 6 shows a fifth embodiment of the present invention. The same components as those of the first embodiment shown in FIG. Is omitted.

In FIG. 6, the third conductor 12 is formed on the surface of the second plate 4 facing the vibrating element 5, and the inside of the package includes the excitation electrode 6 and the second conductor 7. The package is electrically connected to the external electrode 9 on the side surface of the package. The presence of the third conductor 12 enables more reliable electrical conduction between the excitation electrode 6 of the vibration element 5 and the external electrode 9.

(Embodiment 6) FIG. 7 shows Embodiment 6 of the present invention. The same components as those of Embodiment 1 shown in FIG. Is omitted.

FIG. 7 has a feature obtained by combining the second embodiment and the fifth embodiment. In the second embodiment, it has been described that pressure cannot be applied when the adhesive of the support 10 is cured,
According to the present embodiment, since the third conductor 12 is present, a space can be formed between the second plate 4 and the vibrating element 5, so that the pressure is applied when the support 10 is cured. Therefore, the thickness of the support 10 can be made uniform.

(Embodiment 7) FIG. 8 shows an embodiment 7 of the present invention. The same components as those of the embodiment 1 shown in FIG. Is omitted.

In FIG. 8, the bumps of the second conductor 11 are formed on both surfaces of the excitation electrode 6 formed on the front and back surfaces of the vibration element 5. Since the second conductor 11 is formed on both surfaces, a space can be reliably created around the vibrating element 5, and the presence of the first conductor 2 and the third conductor 12 allows In addition, electrical conduction from the excitation electrode 6 to the external electrode 9 can be efficiently performed.

(Eighth Embodiment) FIG. 9 shows an eighth embodiment of the present invention. The same components as those of the first embodiment shown in FIG. Is omitted.

FIG. 9 shows a configuration having a combination of the second and seventh embodiments, and the space between the second plate 4 and the vibrating element 5 shown in the sixth embodiment is more reliably provided. Can be formed.

[0033]

As described above, according to the present invention, a first plate having at least two or more first conductors formed on at least one surface from the inside to the end of the surface, and having a space inside. A vibration element having excitation electrodes formed on the front and back surfaces, a second plate, and an external electrode;
In the package formed by the first plate, the support, and the second plate, fixed by the second conductor, and electrically connected to the excitation electrode and the first conductor via the second conductor. The first conductor is electrically connected to the outside of the package, is electrically connected to the external electrodes, and the first plate and the second plate are each formed of a flat plate. In the piezoelectric vibrator having the support between the two plates, the side of the support located on the side forming the external electrode of the package has a side portion closer to the side of the first plate and the side of the second plate. It is not necessary to form a concave portion that avoids the shape of the vibrating element in the package with a piezoelectric vibrator that is on the inside or that forms the third conductor on the second plate, and special processing is performed. An untreated flat plate can be used as a package, which excites the vibrating element. Together reliably perform the electrical connection to the external electrode from pole, small and the piezoelectric resonator package
The advantageous effect that the thickness can be reduced is obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a piezoelectric vibrator according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the first embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a second embodiment of the present invention.

FIG. 4 is a sectional view showing a third embodiment of the present invention.

FIG. 5 is a sectional view showing a fourth embodiment of the present invention.

FIG. 6 is a sectional view showing a fifth embodiment of the present invention.

FIG. 7 is a sectional view showing a sixth embodiment of the present invention.

FIG. 8 is a sectional view showing a seventh embodiment of the present invention.

FIG. 9 is a sectional view showing an eighth embodiment of the present invention.

10A is an exploded perspective view showing a conventional piezoelectric vibrator packaging method, and FIG. 10B is a sectional view showing a conventional piezoelectric vibrator packaging method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 first plate 2 first conductor 3 support 4 second plate 5 vibrating element 6 excitation electrode 7 second conductor 8 adhesive layer 9 external electrode 10 support 11 second conductor 12 third conductor

Claims (2)

[Claims] 1. A first plate having at least one or more first conductors formed on at least one surface from an intermediate portion to a surface end, a support having a space therein, and excitation electrodes on the front and back surfaces. And a second plate, and an external electrode, wherein the vibration element is in a package formed by the first plate, the support, and the second plate, and has a second conductive property. The excitation electrode and the first conductor are electrically connected to each other through the second conductor, and the first conductor is led out of the package to be connected to the external electrode. The first plate and the second plate are each formed of a flat plate, and the piezoelectric vibrator having the support between the first plate and the second plate; Located on the side surface forming the external electrode A piezoelectric vibrator configured such that a side surface of the support is located inside a side surface of the first plate and a side surface of the second plate. 2. At least two or more third conductors are formed on the surface of the second plate connected to the support from at least one surface from the inside to the end of the surface. The inside of the package is electrically connected to the excitation electrode via the second conductor, and the first and third conductors are electrically connected to the external electrode on the side surface of the package. The piezoelectric vibrator according to the above.