JPH1075151A - Piezo components - Google Patents

Abstract

(57) [Problem] To provide a piezoelectric component which is easy to assemble and has excellent electrical connectivity. The piezoelectric resonator has a piezoelectric resonator having projections made of a conductive resin on both surfaces.
Terminal electrode plates 17, 1 sandwiching 1, 12, 13, 14
8, 19, 20, an insulating member 21, and a U-shaped electrode plate 2 disposed across the piezoelectric resonator 12 and the insulating member 21.
2 in a box-shaped case 23,
4, sealing with sealing resin 25;

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric component incorporating a piezoelectric resonator.

[0002]

2. Description of the Related Art Conventionally, there has been known a piezoelectric component in which a piezoelectric resonator made of ceramics or the like is incorporated and used as an oscillation circuit, a filter circuit, or the like. FIG. 4 is a cross-sectional view of a conventional piezoelectric component, and FIG. 5 is a perspective view (a) showing a piezoelectric resonator constituting the piezoelectric component shown in FIG. 4 and a terminal electrode plate sandwiching the piezoelectric resonator, and its cross section. FIG.

First, the piezoelectric resonator and the terminal electrode plate shown in FIG. 5 will be described. In the piezoelectric resonator 40 shown in FIG. 5, electrodes 40a are formed on both surfaces of the piezoelectric resonator 40. On the other hand, the terminal electrode plate 41 has a support surface 41a for supporting the piezoelectric resonator 40, and a projection 41b is formed at the center of the support surface 41a. Piezoelectric resonator 40
Is sandwiched between two terminal electrode plates 41, and an electrode 40a formed on the piezoelectric resonator 40 and a projection 41b formed on the terminal electrode plate 41 are in electrical contact. here,
When a high-frequency voltage is applied to each of the two terminal electrode plates 41, the piezoelectric resonator 40 resonates at a frequency unique to the piezoelectric resonator 40.

Next, the piezoelectric component shown in FIG. 4 will be described. The piezoelectric component shown in FIG.
A plurality of terminal electrode plates 41; an insulating member 44 disposed at a position between the second piezoelectric resonator 40 and the third piezoelectric resonator 40 from the left shown in FIG. An array component 46 composed of a U-shaped electrode plate 45 disposed across the piezoelectric resonator 40 and the insulating member 44 and a spring member 42
However, it has the structure accommodated in the protective case 43. The piezoelectric resonator 40, the terminal electrode plate 41, the insulating plate 44, and the U-shaped electrode 45, which constitute the array component 46, are pressed by the elastic force of the spring members 42 arranged on the left end of the array component 46. As a result, the electrical contact between the piezoelectric resonator 40 and the terminal electrode plate 41 is maintained. Further, a cover (not shown) is provided in the protective case 43, whereby a part of the terminal electrode plate 41 of the array component 46 is
And is hermetically sealed in the protective case 43 in a state protruding therefrom.

When a voltage is applied to the terminal electrode plate 41 of the piezoelectric component configured as described above, each of the piezoelectric resonators 40 resonates at a specific frequency, and functions as a filter or the like. However, in the case of the piezoelectric component shown in FIG. 4, in assembling, it is necessary to store the arrayed component 46 in the protective case 43 having an open surface while maintaining the arrayed state of the arrayed component 46. Manual work,
After the array components 46 are stored in the protective case 43, the displacement between the components can be adjusted, or the piezoelectric resonator 40 and the terminal electrode plate 4 can be adjusted.
It is necessary to confirm the electrical contact with the device 1 or the like. Therefore, in assembling the piezoelectric component, there is a problem that a high level of skill and many steps are required, resulting in poor production efficiency.

In order to solve this problem, Japanese Patent Laid-Open Publication No. 7-2
One proposal is shown in US Pat. FIG.
FIG. 1 is a perspective view showing a piezoelectric component composed of a plurality of components, which is proposed in Japanese Patent Application Laid-Open No. 7-221585, with a part thereof disassembled. In the piezoelectric component shown in FIG. 6, jigs 67a and 67b utilizing vacuum suction force during assembly.
Thus, the flat plate 69a and the array component 4 constituting the protection case 69
6, the members 69c and 69d constituting the protective case 69 are heated by the joining member 60 together with the flat plate 69a to assemble the protective case 69, thereby forming the array components 4
6 is housed in a protective case 69.

[0007]

In order to obtain the above-mentioned terminal electrode plate constituting the piezoelectric component, for example, a thickness of 0.1 mm is required.
Using a material in which silver bronze is applied to the surface of phosphor bronze having a spring property of about mm, the terminal electrode plate is punched by press working, and the central part of the terminal electrode plate makes electrical contact with the piezoelectric resonator. To form projections. In order to punch such a thin plate having a thickness of about 0.1 mm by press working and to form projections, a high-precision mold is required to ensure flatness of the entire terminal electrode plate. In particular, the terminal electrode plate having projections on both surfaces is manufactured by forming two projections on one electrode plate and then folding the electrode plate. There is a problem such as deterioration.

Also, if the terminal electrode plate is warped during the process of forming the projection, the peripheral portion of the piezoelectric resonator may come into contact with the terminal electrode plate, and in that case, the resonance characteristics are deteriorated. Occurs. In the case of using a plane-resonance mode piezoelectric resonator, it is necessary to align the central portion, which is a node of the vibration of the piezoelectric resonator, with the protrusion of the terminal electrode plate, and further maintain that state. It has to be inserted into a box-shaped case as it is, and in assembling, it is necessary to adopt a more advanced skill and a complicated assembling method disclosed in Japanese Patent Application Laid-Open No. 7-221584. Also, after assembly, if the pressure applied to the piezoelectric resonator is too weak, the electrical contact will be insufficient, and if it is too strong, the resistance in the equivalent circuit of the piezoelectric resonator will increase. In order to properly adjust the contact pressure between the terminal electrode plate and the terminal electrode plate, strict control of the height of the projection of the terminal electrode plate and the use of spacers when inserting the terminal electrode plate into the box-shaped case are required.

In view of the above circumstances, an object of the present invention is to provide a piezoelectric component which is easy to assemble and has excellent electrical connectivity.

[0010]

In order to achieve the above object, a piezoelectric component according to the present invention comprises a piezoelectric resonator, and a plurality of electrode plates sandwiching the piezoelectric resonator. In the piezoelectric component housed in the box body in the state as described above, the plurality of electrode plates have a protrusion made of a conductive resin at a position sandwiched between the electrode plate and the piezoelectric resonator. I do.

In the present invention, since the projection made of conductive resin is formed on the surface of the electrode plate, it is not necessary to form the projection on the electrode plate as in the case of the conventional piezoelectric component. And warpage of the electrode plate is reduced. Also,
It is not necessary to fold the electrode plate, thereby preventing cracking and deterioration in flatness, and obtaining a thin electrode plate having projections on both surfaces.

Since the projection is made of a conductive resin, the height, shape, etc. of the projection can be easily adjusted.
In addition, by changing the composition of the conductive resin, the hardness of the protrusions can be easily adjusted, and the pressing pressure of the conventional piezoelectric parts, which relies on the spring properties of the protrusions and spacers of the terminal electrode plate by pressing, is used. Is easily adjusted, and spurious vibration can be suppressed by the damping effect of the resin.

Further, the projection made of the conductive resin can be accurately formed at the center of the electrode plate, so that the adjustment of the alignment between the terminal electrode plate and the piezoelectric resonator is simplified. Here, as the conductive resin, for example, a resin obtained by dispersing a conductive metal powder in a thermosetting resin such as an epoxy resin and an organic solvent is preferably used. A preferred compounding ratio of the conductive resin is, for example, metal powder: 60 to 95% by weight, thermosetting resin: 20 to 3% by weight, and organic solvent: 20 to 2% by weight.

[0014]

Embodiments of the present invention will be described below. FIG. 1 is a sectional view of a piezoelectric component according to an embodiment of the present invention, and FIG. 2 is a perspective view (a) and a side view (b) of a terminal electrode plate constituting the piezoelectric component shown in FIG. FIG.
In the box-shaped case 23 constituting the piezoelectric component 10 shown in FIG.
Four piezoelectric resonators 11, 12, 13, and 14 are sequentially arranged. Further, the four piezoelectric resonators 11, 12, 13, 1
4, two piezoelectric resonators 11, 1 on the left side shown in FIG.
2, two terminal electrode plates 17 and 18 are arranged, and two terminal electrode plates 19 and 20 are arranged with the right end piezoelectric resonator 14 interposed therebetween. These terminal electrode plates 17, 18, 19, and 20 are respectively provided at the center portions on both sides.
As shown in FIG. 2, dome-shaped projections 15 and 16 made of conductive resin are formed. In addition, terminal electrode plates 17 and 1
8, 19, and 20 have extraction electrodes 17a, 18a, 19a, and 20a for connection to external circuits, respectively.

An insulating member 21 for insulating the piezoelectric resonators 12 and 13 from each other is disposed between the piezoelectric resonators 12 and 13. Further, a U-shaped electrode plate 22 is provided so as to straddle the piezoelectric resonator 12 and the insulating member 21, whereby the piezoelectric resonators 11, 12, and 13 are electrically connected to each other. The upper surface of the case 23 is provided with the extraction electrodes 17a, 1 protruding from the case 23.
A mylar film 24 having holes corresponding to 8a, 19a and 20a is covered, and a sealing resin 25 is fixed on the mylar film 24. Thereby, the piezoelectric component 10 having airtightness as a whole is configured.

FIG. 3 is a diagram showing an equivalent circuit of the piezoelectric component shown in FIG. In the equivalent circuit shown in FIG. 3, the piezoelectric resonators 11, 12, and 13 are connected to each other by the U-shaped electrode plate 22 shown in FIG.
3 and 14 are connected to each other, thereby forming a ladder-type filter having a four-element structure.

In the piezoelectric component of the present embodiment, since projections made of conductive resin are formed on both surfaces of the terminal electrode plate, it is necessary to form projections on the terminal electrode plate by pressing as in the conventional piezoelectric component. This eliminates the need for a high-precision mold to form the protrusions, reduces the warpage of the terminal electrode plate, prevents cracking of the terminal electrode plate and deterioration of flatness, and reduces A thin electrode plate having projections can be obtained. Therefore, it is possible to prevent the resonance characteristics from deteriorating due to the contact between the terminal electrode plate and the peripheral portion of the piezoelectric resonator. Also, unlike the conventional piezoelectric component, the adjustment of the alignment for aligning the center position of the piezoelectric resonator with the projection of the terminal electrode plate is simplified. Further, since the projection is formed of a conductive resin, the elasticity of the projection can adjust the pressing pressure between the terminal electrode plate and the piezoelectric resonator, and can suppress spurious vibration due to the damping effect of the resin.

[0018]

Embodiments of the present invention will be described below with reference to FIGS. First, PZT ceramics having a predetermined composition were formed into a plate shape and fired at 1300 ° C. Next, a paste in which Ag and glass frit were mixed with an organic vehicle and a binder was printed on both surfaces of the ceramics, baked, and further polarized at 2500 V to obtain a PZT veneer. This was cut into a predetermined size.

On the other hand, a terminal electrode plate having a thickness of 0.1 mm
A phosphor bronze plate having a thickness of 5 μm and plated with Ag was used. Next, Ag powder (specific surface area 0.45 m ² /
g, average particle size 1.6 μm, 87% by weight), epoxy resin (7% by weight), alkyd resin (3% by weight), butyl carbitol acetate (1.5% by weight), and terpineol (1. 5% by weight) is potted at the center of both sides of the terminal electrode plate to form a dome-shaped protrusion having a diameter of about 1 mm and a height of 0.5 mm.
Thermal curing was performed at a temperature of 160 ° C. for 2 hours. Thus, the terminal electrode plate having the projections shown in FIG. 2 was obtained.

Next, the piezoelectric resonator, the terminal electrode plate having projections formed thereon, the insulating member, and the U-shaped electrode plate were inserted into a box-shaped case (FIG. 1). Further, a mylar film for blocking sealing resin having a hole corresponding to the extraction electrode of the terminal electrode plate was placed thereon, and the sealing resin was poured onto the mylar film, thereby obtaining an airtight piezoelectric filter. In the present embodiment, the pressing pressure of the piezoelectric resonator is appropriately adjusted due to the elasticity of the projection made of the conductive resin formed on the terminal electrode plate, and the leaf spring required in the conventional structure is used. It became unnecessary and the size could be reduced.

In this embodiment, the piezoelectric resonator and the terminal electrode plate are combined and stored in a box-shaped case after the projection made of the conductive resin potted on the terminal electrode plate is cured. Instead, the piezoelectric resonator and the terminal electrode plate may be bonded to each other to form an integrated structure before the projection made of the conductive resin potted on the terminal electrode plate is cured, and then housed in a box-shaped case. . As the conductive resin, a conductive resin such as an ultraviolet curable resin other than the thermosetting conductive resin used in this embodiment may be used.

[0022]

As described above, according to the present invention,
A piezoelectric component that is easy to assemble and has excellent electrical connectivity is obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a piezoelectric component according to an embodiment of the present invention.

FIGS. 2A and 2B are a perspective view and a side view of a terminal electrode plate constituting the piezoelectric component shown in FIG.

FIG. 3 is a diagram showing an equivalent circuit of the piezoelectric component shown in FIG.

FIG. 4 is a sectional view of a conventional piezoelectric component.

5A is a perspective view showing a piezoelectric resonator constituting the piezoelectric component shown in FIG. 4, and FIG. 5B is a perspective view showing a terminal electrode plate sandwiching the piezoelectric resonator, and FIG.

FIG. 6 is proposed in Japanese Patent Application Laid-Open No. 7-221584;
It is a perspective view which shows a piezoelectric component comprised from a some component part by decomposing | disassembling a part.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Piezoelectric component 11, 12, 13, 14 Piezoelectric resonator 15, 16 Projection 17, 18, 19, 20 Terminal electrode plate 17a, 18a, 19a, 20a Extraction electrode 21 Insulating member 22 U-shaped electrode plate 23 Case 24 Myra Film 25 sealing resin

Claims (1)

[Claims] 1. A piezoelectric component comprising: a piezoelectric resonator; and a plurality of electrode plates sandwiching the piezoelectric resonator, housed in a box with a part of the electrode plate protruding. A piezoelectric component comprising: a plurality of electrode plates each having a projection made of a conductive resin at a position between the electrode plate and the piezoelectric resonator.