JPH1032461A - Piezo components - Google Patents

Abstract

(57) [Problem] To provide a piezoelectric component which is easy to assemble and has excellent electrical connectivity. A cable 29 having an insulating coating 29e formed on a portion other than a part of a conductive film 29a, 29b, 29c, 29d is connected to four piezoelectric resonators 21, 22, 23, 24,
And four terminal electrode plates 25, 26, 27, 28, and the necessary connection portions are joined with a conductive resin 30.
Flat screws 31, 32 attached to both ends of the cable 29
Was fitted into the grooves 33a and 33b of the box-shaped case 33.

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. 6 is a cross-sectional view of a conventional piezoelectric component, and FIG. 7 is a perspective view (a) showing a piezoelectric resonator constituting the piezoelectric component shown in FIG. 6 and a terminal electrode plate sandwiching the piezoelectric resonator, and a cross section thereof. FIG.

First, the piezoelectric resonator and the terminal electrode plate shown in FIG. 7 will be described. In the piezoelectric resonator 60 shown in FIG. 7, electrode films 60a are formed on both surfaces of the piezoelectric resonator 60. On the other hand, the terminal electrode plate 61 has a support surface 61a for supporting the piezoelectric resonator 60, and a projection 61b is formed at the center of the support surface 61a. Piezoelectric resonator 60
Are sandwiched between two terminal electrode plates 61, and an electrode film 60a formed on the piezoelectric resonator 60 and a projection 61b formed on the terminal electrode plate 61 are in electrical contact. Here, when a voltage is applied to each of the two terminal electrode plates 61, the piezoelectric resonator 60 resonates at a frequency unique to the piezoelectric resonator 60.

Next, the piezoelectric component shown in FIG. 6 will be described. The piezoelectric component shown in FIG.
A plurality of terminal electrode plates 61; an insulating member 64 disposed at a position between the second piezoelectric resonator 60 and the third piezoelectric resonator 60 from the left shown in FIG. An array component 6 including a U-shaped electrode plate 65 disposed across the piezoelectric resonator 60 and the insulating member 64, and a spring member 62
6 has a structure housed in the protective case 63.
The piezoelectric resonator 60, the terminal electrode plate 61, the insulating plate 64, and the U-shaped electrode 65, which constitute the array component 66,
It is pressed by the elastic force of the spring member 62 arranged at the left end of the arrangement component 66, so that the electrical contact between the piezoelectric resonator 60 and the terminal electrode plate 61 is maintained. Further, a cover (not shown) is provided in the protective case 63, so that a part of the terminal electrode plate 61 of the array component 66 is
3 and sealed in a protective case 63.

When a voltage is applied to the terminal electrode plate 61 of the piezoelectric component configured as described above, each of the piezoelectric resonators 60 resonates at a specific frequency, and functions as a filter or the like. However, in the case of the piezoelectric component shown in FIG. 6, in assembling, the arrangement state of the arrangement parts 66 must be maintained, and the arrangement parts 66 must be stored in the protective case 63 having an open surface. It is necessary to adjust the displacement between the components, check the electrical contact between the piezoelectric resonator 60 and the terminal electrode plate 61, etc. after performing the necessary manual work and storing the arrayed components 66 in the protective case 63. 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. 8, jigs 87a and 87b utilizing vacuum suction force for assembling.
Thus, the flat plate 89a constituting the protective case 89 and the array component 6
6, the members 89c and 89d forming the protective case 89 are heated by the joining member 80 together with the flat plate 89a to assemble the protective case 89.
6 is housed in a protective case 89.

[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, a terminal electrode plate is punched by press working, and a central portion 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. Also, if warpage occurs in the terminal electrode plate during the process of forming the projection, the peripheral portion of the piezoelectric resonator may come into contact with the terminal electrode plate,
In that case, problems such as deterioration of resonance characteristics occur.

In the case of using a surface-spreading mode piezoelectric resonator, it is necessary to align the central portion, which is a node of vibration of the piezoelectric resonator, with the projection of the terminal electrode plate. Must be inserted into a box-shaped case while maintaining the same. For assembly, it is necessary to employ a more advanced skill and a complicated assembly 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, it is necessary to strictly control the protrusion height of the terminal electrode plate and properly adjust the distance between the piezoelectric resonator and the case when inserting it into a box-shaped case. It is necessary to take measures such as using a spacer.

In addition to these factors, a desired piezoelectric resonator among the piezoelectric resonators arranged in a line and a piezoelectric resonator adjacent to the piezoelectric resonator are jumped and electrically connected to the next piezoelectric resonator. The assembly is complicated, for example, by using a U-shaped electrode plate. In view of the above circumstances, the present invention
An object of the present invention is to provide a piezoelectric component that is easy to assemble and has excellent electrical connectivity.

[0010]

According to the present invention, there is provided a piezoelectric component in which a plate-like piezoelectric resonator is housed in a box and external electrodes for supplying power from the box to the piezoelectric resonator. Wherein the piezoelectric resonator has a through-hole connecting both surfaces and has respective electrode films on both surfaces, and the electrode film and the external electrode have a conductive resin in the through-hole. And a cable having a wiring for electrically connecting the electrode film and the external electrode with each other is inserted.

In the present invention, since the cable is inserted into the through hole of the piezoelectric resonator, the peripheral portion of the piezoelectric resonator contacts the case or the like by inserting both ends of the cable into, for example, grooves of the case. It can be held without. Therefore, excellent resonance characteristics can be obtained. In addition, since the electrode film formed on the piezoelectric resonator and the external electrode for supplying power to the piezoelectric resonator are joined by a conductive resin via the wiring of a cable, these electrode films and the external electrode Connection is reliably performed as compared with the mechanical contact between the electrode film and the external electrode in the conventional piezoelectric component. Also, a spacer for holding the electrode film and the external electrode at a constant pressing pressure required by mechanical contact is not required.

[0012]

Embodiments of the present invention will be described below. First, the concept of the present embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating a cable and a piezoelectric resonator having a through hole. The cable 15 shown in FIG.
An insulating coating 14 is applied to a round bar 13 having conductor films 11 and 12 as two independent wirings. This cable 15 is connected to a through hole 16 formed in the center of the piezoelectric resonator 16.
a of the conductor film 11 of the cable 15 and the electrode film 1 on the surface of the piezoelectric resonator 16.
6b, a lower conductor film 12a which is a part of the conductor film 12 of the cable 15, and an electrode film 16c on the back surface of the piezoelectric resonator 16.
Are joined by a conductive resin, so that the cable 15 and the piezoelectric resonator 16 can be electrically and mechanically connected. Similarly, a terminal electrode plate having an external electrode (not shown) can be electrically and mechanically connected. Further, by holding both ends of the cable 15 in a case, the peripheral portion of the piezoelectric resonator 16 can be held without contacting the case and the terminal electrode plate, so that excellent resonance characteristics can be obtained.

When a plurality of piezoelectric resonators are used and these piezoelectric resonators are electrically connected in the form of a ladder as shown in FIG. With such a wiring, the piezoelectric resonators can be easily connected to each other in a ladder shape. In addition, since the electrical connection is reliably performed by the conductive resin, it is not necessary to maintain a constant pressing pressure required for the conventional mechanical contact.

FIG. 2 is a sectional view of a piezoelectric component according to an embodiment of the present invention, and FIG. 3 is a top view of the piezoelectric component shown in FIG.
FIG. 4 is a diagram (a) showing a cable before insulation coating and a diagram (b) showing a cable after insulation coating, which constitutes the piezoelectric component shown in FIG. As shown in FIG. 4A, a cable 29 constituting the piezoelectric component 20 shown in FIG.
The two conductor films 29a, 29b, 29c, 29d are formed, and the conductor films 29a, 29b, 29c,
An insulating coating 29d shown in FIG. 4B is provided on the portion of 29d other than the portions connected to the four piezoelectric resonators 21, 22, 23, 24 and the four terminal electrode plates 25, 26, 27, 28.
e is formed. Each of the four piezoelectric resonators 21, 22, 23, and 24 shown in FIG. 2 has a through hole and an electrode film as shown in FIG.
26, 27 and 28 are piezoelectric resonators 21, 22, 23, 2
4 for supplying electric power to the electrode 4 (external electrodes) 25a, 26a, 27a, and 28a shown in FIG. The cable 29 has four piezoelectric resonators 21, 22, 23, 2
Four and four terminal electrode plates 25, 26, 27, 28 are inserted therethrough. 2, the conductive films 29a, 29b, 29c and 29d formed on the cable 29 are bonded to the piezoelectric resonators 21, 22, 23 and 24 and the terminal electrode plates 25, 26, 27 and 28 by the conductive resin 30. Have been. At both ends of the cable 29, a flat screw 31, which has a T-shaped head,
32, and these flat screws 31, 32 are attached.
Are fitted in the grooves 33a and 33b of the box-shaped case 33.

The upper surface of the case 33 is
Are covered with a mylar film (not shown) having holes corresponding to the extraction electrodes 25a, 26a, 27a, 28a of the terminal electrode plates 25, 26, 27, 28 projecting therefrom,
A sealing resin is fixed on the mylar film. Thereby, the piezoelectric component 20 having airtightness as a whole is configured.

FIG. 5 is a diagram showing an equivalent circuit of the piezoelectric component 20 shown in FIG. The equivalent circuit of the piezoelectric component 20 shown in FIG. 5 is such that the piezoelectric resonators 21, 22, and 23 are connected to each other by the conductive film 29b and the conductive resin 30 shown in FIG. The resonators 23 and 24 are connected to each other, thereby forming a ladder-type filter having a four-element structure.

[0017]

Embodiments of the present invention will be described below. First, PZT ceramics prepared to a predetermined composition were formed into a plate shape. At this time, a molding die was used such that when cut into final elements (piezoelectric resonators), a through hole having a diameter of 1.5 mm was formed at the center of each element. 1300
After firing at ℃, a paste in which Ag and glass frit were mixed with an organic vehicle and a binder was printed on both sides and fired. Furthermore, it was polarized at 2500 V to obtain a PZT veneer. This was cut into a predetermined size.

Next, as shown in FIG.
A conductor film was formed on a resin-made round bar of mm. Next, FIG.
As shown in (b), an insulating coating made of an epoxy resin was formed except for a connection portion between the piezoelectric resonator and the terminal electrode plate, and a cable having a diameter of 1.5 mm as a whole was manufactured. Next, a cable is inserted through the four terminal electrode plates and the four piezoelectric resonators so that the terminal electrode plate and the piezoelectric resonator are at predetermined positions with respect to the exposed portions of the conductor film formed on the cables. Was positioned. In addition, T
A flat screw with a U-shaped head was attached.

Next, a conductive resin is applied to each connection part,
Thermal curing was performed at 60 ° C. for 2 hours. Examples of the conductive resin include 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 resin A paste obtained by kneading carbitol acetate (1.5% by weight) and terpineol (1.5% by weight) was used.

After thermosetting, a flat screw was pushed in along the groove formed in the resin case. As a result, tension was applied to the cable, and the piezoelectric resonator and the terminal electrode plate could be housed without contacting each other and without contacting the piezoelectric resonator with the case (see FIGS. 2 and 3). Figure 2
In FIG. 3, the portions painted black are the conductive resin and the conductor film section of the cable. As is clear from FIGS. 2 and 3, it can be seen that the electrical connection shown in FIG. 5 was achieved by selectively exposing the conductor film formed on the cable depending on the presence or absence of the insulating coating.

Finally, a Mylar film for closing the sealing resin having a hole corresponding to the extraction electrode of the terminal electrode plate is placed from above the box-shaped case, and the sealing resin is poured onto the Mylar film. Thus, an airtight piezoelectric filter was obtained. Since the piezoelectric resonator could be lifted inside the case by holding it with a cable, the peripheral part of the piezoelectric resonator did not come into contact with the case, reducing the deterioration of characteristics and reducing the assembly required conventionally. In this case, it is no longer necessary to precisely adjust the position of the protrusion formed at the center of the terminal electrode plate and the piezoelectric resonator. Further, in the conventional piezoelectric component, a leaf spring, which was necessary for appropriately adjusting the contact pressure between the terminal electrode plate and the piezoelectric resonator, became unnecessary, and the size could be reduced.

In this embodiment, a thermosetting conductive resin is used as the conductive resin. However, the present invention is not limited to this. For example, an ultraviolet curable conductive resin may be used as the conductive resin. You may.

[0023]

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 diagram showing a cable and a piezoelectric resonator having a through hole.

FIG. 2 is a sectional view of a piezoelectric component according to an embodiment of the present invention.

FIG. 3 is a top view of the piezoelectric component shown in FIG. 2;

FIGS. 4A and 4B are diagrams showing a cable before insulation coating and a cable after insulation coating, which constitute the piezoelectric component shown in FIG. 1;

FIG. 5 is a diagram showing an equivalent circuit of the piezoelectric component 20 shown in FIG.

FIG. 6 is a sectional view of a conventional piezoelectric component.

7A is a perspective view showing a piezoelectric resonator constituting the piezoelectric component shown in FIG. 6, and FIG. 7B is a perspective view showing a terminal electrode plate sandwiching the piezoelectric resonator, and FIG.

FIG. 8 is proposed in Japanese Patent Application Laid-Open No. 7-221584;
It is a perspective view which shows a piezoelectric component which consists of several components by decomposing | disassembling a part.

[Explanation of symbols]

11, 11a, 12, 12a, 29a, 29b, 29
c, 29d Conductive film 13 Round bar 15, 29 Cable 14, 29e Insulating coating 16, 21, 22, 23, 24 Piezoelectric resonator 16a Through hole 16b, 16c Electrode film 20 Piezoelectric component 25, 26, 27, 28 Terminal electrode plate 25a, 26a, 27a, 28a Extraction electrode 30 Conductive resin 31, 32 Flat screw 33 Case 33a, 33b Groove

Claims (1)

[Claims] 1. A piezoelectric component comprising a plate-shaped piezoelectric resonator housed in a box and an external electrode for supplying power to the piezoelectric resonator protruding from the box, wherein the piezoelectric resonator has two sides. It has a through hole for connecting and has each electrode film on both sides, and is electrically connected to the electrode film and the external electrode with a conductive resin in the through hole to electrically connect the electrode film and the external electrode. A piezoelectric component, wherein a cable having wiring to be connected is inserted.