JPH0637576A - Piezo-resonator - Google Patents

Abstract

PURPOSE:To obtain a piezo-resonator having an external electrode surely connected to an electrode formed on a piezoelectric substrate and having high reliability. CONSTITUTION:Terminal members 18, 20 are mounted on both terminals of the piezoelectric substrate 12 on both planes of which the electrodes 14, 16 are formed. The terminal members 18, 20 are formed in cross-sectional U-shape with conductive materials. First sealing plates 22, 24 are mounted on both side planes of the terminal members 18, 20. Furthermore, an aperture part formed with the terminal members 18, 20 and the first sealing plates 22, 24 is sealed with second sealing plates 26, 28. The external electrodes 30, 32 are formed so as to connect electrically to the terminal members 18, 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric resonator, and more particularly, it relates to a piezoelectric resonator having a member for protecting a piezoelectric substrate and securing a vibration space of the piezoelectric substrate.

[0002]

2. Description of the Related Art FIG. 5 is a perspective view showing an example of a conventional piezoelectric resonator which is the background of the present invention. The piezoelectric resonator 1 includes a piezoelectric substrate, and a first sealing member 2 and a second sealing member 3 are formed so as to surround the periphery of the piezoelectric substrate. The external electrodes 4 are formed on both ends of the first sealing member 2 and the second sealing member 3. The external electrode 4 is connected to an electrode formed on the piezoelectric substrate.

To manufacture such a piezoelectric resonator 1,
As shown in FIG. 6A, the piezoelectric substrate 5 is prepared.
Electrodes 6 are formed on both surfaces of the piezoelectric substrate 5 so as to face each other at their central portions. The U-shaped first sealing member 2 is attached so as to sandwich the piezoelectric substrate 5. As a result, as shown in FIG. 6B, space portions are formed on both sides of the piezoelectric substrate 5, and a vibration space for the piezoelectric substrate 5 is secured. Further, as shown in FIG. 6 (C), the opening of the first sealing member 2 is closed so that the second
The sealing member 3 is attached. Next, the external electrodes 4 are formed on the exposed ends of the piezoelectric substrate 5 and the electrodes 6, whereby the piezoelectric resonator 1 shown in FIG. 5 is manufactured.

[0004]

However, in such a piezoelectric resonator, the piezoelectric substrate is exposed at the ends of the first sealing member and the second sealing member. For this reason, moisture easily enters from the exposed portion of the piezoelectric substrate and mechanical damage to the piezoelectric substrate occurs, so that the reliability is likely to decrease. Moreover, since the electrodes formed on the piezoelectric substrate are thin, the areas of the electrodes exposed at the ends of the first and second sealing members are small. Therefore, when the external electrode is formed, the electrical connection between the external electrode and the electrode formed on the piezoelectric substrate may become insufficient.

Therefore, a main object of the present invention is to provide a highly reliable piezoelectric resonator having an external electrode reliably connected to an electrode of a piezoelectric substrate.

[0006]

According to the present invention, a piezoelectric substrate, electrodes formed on the piezoelectric substrate, and a conductive material attached to both ends of the piezoelectric substrate so as to be connected to the electrodes are formed. A piezoelectric resonator including an end member and a sealing plate formed on both sides of the end member and disposed on both sides of the piezoelectric substrate at a distance from the piezoelectric substrate. In this piezoelectric resonator, arranged on both sides of the sealing plate and the end member,
Another sealing plate for covering the piezoelectric substrate may be formed.

[0007]

The piezoelectric substrate is protected by the end member and the sealing plate. At this time, since a space is provided between the piezoelectric substrate and the sealing plate, a vibration space for the piezoelectric substrate is secured. Furthermore, if another sealing plate is used, the piezoelectric substrate is sealed and the exposed portion is eliminated. Further, an end member made of a conductive material is attached to the electrode formed on the piezoelectric substrate, and the end member is exposed to the outside.

[0008]

According to the present invention, since the piezoelectric resonator can be formed without exposing the piezoelectric substrate,
It is possible to prevent moisture from entering and mechanical damage to the piezoelectric substrate. Therefore, the reliability of the piezoelectric resonator can be improved as compared with the conventional piezoelectric resonator. Further, an end member made of a conductive material is attached to the electrode formed on the piezoelectric substrate, and the end member is exposed to the outside. The exposed portion of the end member has a larger area than when the electrode formed on the piezoelectric substrate is exposed. Therefore, when the external electrode is formed on the end portion of the piezoelectric resonator, the electrical connection between the electrode formed on the piezoelectric substrate and the external electrode can be ensured.

The above-mentioned objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of the embodiments with reference to the drawings.

[0010]

1A is a perspective view showing an embodiment of the present invention, and FIG. 1B is an exploded perspective view thereof. The piezoelectric resonator 10 includes a piezoelectric substrate 12. Electrodes 14 and 16 are formed on both surfaces of the piezoelectric substrate 12, respectively. One electrode 14 is formed so as to extend from one end of the one main surface of the piezoelectric substrate 12 toward the other end. The other electrode 16 is formed to extend from the other end of the other main surface of the piezoelectric substrate 12 toward the one end. The electrodes 14 and 16 are formed so as to face each other near the center of the piezoelectric substrate 12.

End members 18 and 20 are attached to both ends of the piezoelectric substrate 12. The end members 18 and 20 are formed in a U-shaped cross section and are fitted into both ends of the piezoelectric substrate 12. At this time, one end member 18 is attached so as to be connected to the electrode 14, and the other end member 20 is attached to the electrode 16.
It is attached so that it is connected to. These end members 1
8, 20 are formed of a conductive material such as metal. Further, as the material of the end members 18 and 20, a conductive film may be formed on the surface of the molded body formed of an insulating material. Since these end members 18 and 20 are formed in a U-shape in cross section, they make surface contact with the electrodes 14 and 16 formed on the piezoelectric substrate 12, and ensure electrical connection.

First sealing plates 22 and 24 are attached to both sides of the end members 18 and 20, respectively. First sealing plate 2
The piezoelectric substrates 1 and 2 are formed by bonding, for example.
It is attached to the side surfaces of the end members 18 and 20 so as to be parallel to the main surface of 2. These first sealing plates 22, 24
Is attached to the side surfaces of the end members 18 and 20, and is thus spaced from the piezoelectric substrate 12. By thus forming the space between the piezoelectric substrate 12 and the first sealing plates 22 and 24, the vibration space of the piezoelectric substrate 12 is secured.

Further, the second sealing plate 2 is provided on the side surface of the piezoelectric substrate 12 which is orthogonal to the main surface thereof by, for example, bonding.
6 and 28 are attached. Second sealing plates 26, 2
8 is the first sealing plates 22 and 24 and the end members 18 and 20.
It is attached so as to close the opening formed by. First
The sealing plates 22 and 24 and the second sealing plates 26 and 28 of
It is made of an insulating material. Furthermore, the first sealing plates 22, 2
External electrodes 30 and 32 are formed on both ends of the fourth and second sealing plates 26 and 28. These external electrodes 30,
32 is electrically connected to the end members 18 and 20.

In order to manufacture this piezoelectric resonator 10, FIG.
As shown in (A), the piezoelectric substrate 34 is formed. Electrodes 36 and 38 are formed on both surfaces of the piezoelectric substrate 34, respectively. These electrodes 36 and 38 are formed so as to extend from the end portions of both surfaces of the piezoelectric substrate 34, respectively, and are formed to face each other near the central portion of the piezoelectric substrate 34. The piezoelectric substrate 34 is formed wider than the piezoelectric substrate 12 shown in FIG. 1B, and the piezoelectric substrate 34 is obtained by cutting the piezoelectric substrate 34 in the direction in which the electrodes 36 and 38 extend and face each other. .

As shown in FIG. 2B, end members 40 and 42 are attached to the ends of the piezoelectric substrate 34 where the electrodes 36 and 38 are formed, respectively. These end members 40,
The length of 42 is formed according to the length of the end portion of the piezoelectric substrate 34. The end members 40 and 42 may be attached by, for example, fitting or caulking. Further, as shown in FIG. 2C, first sealing plates 44 and 46 are attached to both side surfaces of the end members 40 and 42 so as to cover the main surface of the piezoelectric substrate 34. Then, the end members 40 and 42 and the first sealing plate 4
By cutting the piezoelectric substrate 34 to which the Nos. 4, 46 are attached, as shown in FIG.
And the piezoelectric substrate 12 to which the first sealing plates 22 and 24 are attached is obtained. And the end members 18, 20 and the first
The opening formed by the sealing plates 22 and 24 of FIG.
As shown in (E), it is closed by the second sealing plates 26 and 28.

In this state, the piezoelectric substrate 12 is not exposed to the outside, and the first sealing plates 22 and 24 and the second sealing plate 2 are not exposed.
End members 18 and 20 are exposed at the ends of 6 and 28. External electrodes 30, 3 are formed on the exposed portions of the end members 18, 20.
By forming 2, the piezoelectric resonator 10 is formed. The external electrodes 30 and 32 are formed by sputtering, for example, and solder dipping may be further performed thereon.

In this piezoelectric resonator 10, the piezoelectric substrate 12 is used.
Is not exposed to the outside. Therefore, as compared with the conventional piezoelectric resonator in which the piezoelectric substrate is exposed, moisture in the air is less likely to enter, and the piezoelectric substrate 12 is less likely to be mechanically damaged. Therefore, the reliability of the piezoelectric resonator 10 can be improved. In addition, the area of the exposed portions of the end members 18 and 20 connected to the electrodes 14 and 16 formed on the piezoelectric substrate 12 is larger than that when the electrodes 14 and 16 are exposed, and the external electrodes 30 and 32 are large. The electric connection with can be reliably performed. Moreover, the end members 18, 20
Is reliably connected to the electrodes 14 and 16, so that the piezoelectric resonator 10 can be reliably operated by connecting an external circuit to the external electrodes 30 and 32. In this way, the piezoelectric resonator 10 can be improved in electrical reliability.

In the case of manufacturing this piezoelectric resonator 10, it is also possible to form a plurality of piezoelectric substrates 34 in the lateral direction and to stack them in a plurality of stages, as shown in FIG. 3 (A), for example. In this case, the end members 50 at both ends have the same shape as the end members 40 and 42 shown in FIG. 2, but the end member 52 arranged in the middle has concave portions for holding the piezoelectric substrate 34 on both sides thereof. It is formed. A plurality of piezoelectric substrates 34 are held by using these end members 50 and 52. And
The piezoelectric substrates 34 held by the end members 50 and 52 are stacked in a plurality of stages with the first sealing plate 54 interposed therebetween. Further, another first sealing plate 56 is attached to both sides of the piezoelectric substrate 34 laminated in a plurality of stages. However, as the first sealing plate 54 arranged in the middle part, one having a larger thickness than the first sealing plates 56 arranged on both sides is used.
This is because, as will be described later, the first sealing plate 54 arranged in the middle portion is cut.

Next, as shown in FIG. 3B, the laminated piezoelectric substrate 34 and the first sealing plates 54 and 56 are cut into a predetermined width. Further, as shown in FIG. 3C, second sealing plates 58 and 60 are attached so as to close the openings formed by the end members 50 and 52 and the first sealing plates 54 and 56. . In this state, as shown by the alternate long and short dash line in FIG. 3C, the cutting is performed at the first sealing plate 54 portion and the end member 52 portion arranged in the middle portion. Therefore, the end members 54 and 56 are exposed on the cut surface, and the external electrodes 30 and 32 are formed on the end members 54 and 56, whereby the piezoelectric resonator 10 is formed.
Is formed.

Further, as shown in FIG. 4, it is possible to change the shape of the end member. In the case of the embodiment shown in FIG.
The end member 62 at the end portion and the end member 64 at the intermediate portion are integrally formed in a state of being connected in a direction in which the piezoelectric substrate 34 is laminated in a plurality of stages. Such end members 62, 64
Using a plurality of piezoelectric substrates 34, a first sealing plate 66 arranged in the middle portion, and a first sealing plate 6 arranged on both sides.
8, the piezoelectric resonator 10 is manufactured in the same manner as the method shown in FIG. However, when the laminated body of the piezoelectric substrate 34 is cut after the second sealing plate is attached, it is cut so as to remove the connecting portion of the end members 60 and 62 as shown by the alternate long and short dash line in FIG. . In this way, the piezoelectric substrate 34
The individual end members may be used for stacking, or the connected end members may be used.

As described above, in the method of stacking a plurality of piezoelectric substrates 34, the number of piezoelectric substrates 34 arranged in the lateral direction and the number of stages of stacking the piezoelectric substrates 34 can be arbitrarily changed, and the piezoelectric resonator 10 can be manufactured. The mass productivity is high. Further, by using such a manufacturing method, it is possible to cope with various shapes and sizes of the piezoelectric substrate by changing the shape of the end member, and it is also possible to form a cavity for obtaining a vibration space. It's easy. As described above, by using the method shown in FIGS. 3 and 4, the degree of freedom in designing the piezoelectric resonator is large, and the added value can be increased.

[Brief description of drawings]

FIG. 1A is a perspective view showing an embodiment of the present invention, and FIG. 1B is an exploded perspective view thereof.

2A to 2E are perspective views showing an example of a method for manufacturing the piezoelectric resonator shown in FIG.

3A to 3C are perspective views showing another example of a method for manufacturing the piezoelectric resonator shown in FIG.

4 is a perspective view showing a step of still another manufacturing method of the piezoelectric resonator shown in FIG. 1. FIG.

FIG. 5 is a perspective view showing an example of a conventional piezoelectric resonator which is the background of the present invention.

6A to 6C are perspective views showing a method of manufacturing the conventional piezoelectric resonator shown in FIG.

[Explanation of symbols]

 10 Piezoelectric Resonator 12 Piezoelectric Substrate 14,16 Electrode 18,20 End Member 22,24 First Sealing Plate 26,28 Second Sealing Plate 30,32 External Electrode 34 Piezoelectric Substrate 36,38 Electrode 40, 42 end member 44,46 first sealing plate 50,52 end member 54,56 first sealing plate 58,60 second sealing plate 62,64 end member 66,68 first sealing plate

Claims (2)

[Claims] 1. A piezoelectric substrate, an electrode formed on the piezoelectric substrate, end members made of a conductive material attached to both ends of the piezoelectric substrate so as to be connected to the electrodes, and the end member. A piezoelectric resonator including sealing plates formed on both sides of the piezoelectric substrate and disposed on both sides of the piezoelectric substrate at a distance from the piezoelectric substrate. 2. The piezoelectric resonator according to claim 1, further comprising another sealing plate disposed on both sides of the sealing plate and the end member to cover the piezoelectric substrate.