JPH06334470A - Piezoelectric element and piezoelectric resonance component - Google Patents

Abstract

PURPOSE:To obtain a piezoelectric element by forming an electrode with at least one kind of alloys Cu-Ni, Ni-Cr and Cr-Si with excellent anti-oxidation, anti-suluerization and corrosion-proof without occurrence of silver migration. CONSTITUTION:A piezoelectric element 2 has an electrode 210 on the surface of a piezoelectric ceramic material 200 and the electrode is made of at least one kind of alloys Cu-Ni, Ni-Cr and Cr-Si. The piezoelectric ceramic material 200 is polarized with respect to the provided electrode 210 so as to obtain desired vibration modes such as area spread vibration, lengthwise vibration and bending vibration modes. The electrode 210 is excellent in the anti-oxidation, anti-sulfurization and corrosion-proof and no silver migration is caused. Thus, the piezoelectric element with high reliability is obtained, in which improper contact hardly takes place between the electrode 210 of the piezoelectric element 2 and an electric connection means such as terminals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric element and a piezoelectric resonance component such as a ladder type ceramic filter using the piezoelectric element.

[0002]

2. Description of the Related Art Conventionally, Ag and Cu have been used as electrodes for piezoelectric elements.
Alternatively, Ni by electroless plating of Ni has been used. For example, Japanese Utility Model Publication No. 4-132735 discloses a technique of forming a baking electrode using an Ag paste containing a certain kind of inorganic additive.

[0003]

However, since the Ni electrode by Ni electroless plating involves immersing the piezoelectric ceramic body in a plating solution which is a chemical solution during the plating process, the piezoelectric ceramic body is plated. There are problems such as deterioration due to the liquid and deterioration of reliability due to the influence of floating substances in the plating liquid. In the case of an Ag electrode, well-known silver migration occurs. The Cu electrode is easily oxidized or sulfided by soldering or the like, and a contact failure is likely to occur between the Cu electrode and an electrical connection means such as a terminal.

Therefore, an object of the present invention is to provide a highly reliable piezoelectric element having excellent oxidation resistance, sulfidation resistance, corrosion resistance and no room for silver migration, and a piezoelectric resonance having improved reliability using the piezoelectric element. It is to provide parts.

Another object of the present invention is to provide a piezoelectric element which does not cause chemical deterioration of the electrode in the electrode forming step, and a piezoelectric resonance component having improved reliability using the piezoelectric element.

Still another object of the present invention is to provide a piezoelectric resonance component in which the electrodes have a resistance component and the group delay characteristics when used as a filter are improved.

[0007]

In order to solve the above problems, the present invention is a piezoelectric element having electrodes on the surface of a piezoelectric ceramic body, wherein the electrodes are Cu-Ni alloy, Ni-C.
It is composed of at least one of r alloy and Cr-Si alloy.

A piezoelectric resonance component according to the present invention includes a case,
A piezoelectric resonance component including a plurality of piezoelectric resonators and a plurality of terminal plates, wherein the case has an internal space, each of the piezoelectric resonator is a piezoelectric element according to the present invention described above. And is an element that utilizes a surface-spreading vibration mode, each of the terminal plates contacts the piezoelectric resonator on a node generated on the surface of the piezoelectric resonator, and the portion other than the contact point is the piezoelectric resonance. Remote from the face of the child, the piezoelectric resonator and the terminal plate are stacked to form a ladder circuit, at least the periphery of the piezoelectric resonator is spaced from the inner wall surface of the internal space, It is located in the interior space.

[0009]

Function: Cu-Ni alloy, Ni-Cr alloy or Cr-
An electrode composed of at least one of Si alloys,
It has excellent oxidation resistance, sulfidation resistance and corrosion resistance, and there is no room for silver migration. Therefore, it is possible to obtain a highly reliable piezoelectric element in which poor contact is unlikely to occur between the electrode of the piezoelectric element and an electrical connecting means such as a terminal.

The electrode made of the above alloy can be formed by means such as sputtering or vacuum deposition. For this reason,
Unlike the case of the Ni electrode formed by Ni electroless plating, chemical deterioration of the electrode does not occur in the electrode forming process.

Since the piezoelectric resonance component according to the present invention uses the above-described piezoelectric element as a resonator, the advantages of the above-described piezoelectric element are reflected as they are. Therefore, it is possible to obtain a highly reliable piezoelectric resonance component in which poor contact does not easily occur between the electrode of the piezoelectric resonator and the terminal plate.

Cu-Ni alloy, Ni-Cr alloy or C
When an electrode made of at least one of r-Si alloys is used as a filter, the electrode has an appropriate electric resistance value, so that the Q value of the piezoelectric vibrator is effectively reduced, so that the group delay characteristic is improved. You can For this reason,
The group delay characteristic can be improved without using a resistor.

In the piezoelectric resonance component according to the present invention, each of the piezoelectric resonators is an element utilizing the surface expansion vibration mode, and each of the terminal plates is in contact with a node generated on the surface of the piezoelectric resonator and is a portion excluding a contact point. Is separated from the surface of the piezoelectric resonator, the influence of the terminal plate on the surface expansion vibration mode of the piezoelectric resonator can be minimized.

The piezoelectric resonator and the terminal plate are laminated to form a ladder circuit, and at least the periphery of the piezoelectric resonator is arranged in the internal space so as to be spaced from the inner wall surface of the internal space. It is possible to obtain a ladder-type piezoelectric resonance component incorporated in a case without causing characteristic fluctuation due to contact with.

[0015]

1 is a front view of a piezoelectric element according to the present invention, and FIG.
FIG. 2 is a partially enlarged view of the piezoelectric element shown in FIG. The piezoelectric element 2 has an electrode 210 on the surface of the piezoelectric ceramic body 200. The electrode 210 is made of at least one of a Cu-Ni alloy, a Ni-Cr alloy, and a Cr-Si alloy. The piezoelectric ceramic body 200 has an electrode 210 provided with it.
With respect to, for example, polarization is performed so as to obtain a desired vibration mode such as surface expansion vibration, length vibration, or bending vibration.

Cu-Ni alloy, Ni-Cr alloy or C
The electrode 210 composed of at least one of r-Si alloys has excellent oxidation resistance, sulfidation resistance and corrosion resistance, and there is no room for silver migration to occur. Therefore, it is possible to obtain a highly reliable piezoelectric element in which contact failure is less likely to occur between the electrode 210 of the piezoelectric element 2 and an electrical connecting unit such as a terminal.

The electrode 210 made of the above alloy is formed by means such as sputtering or vacuum deposition. Therefore, unlike the case of the Ni electrode by Ni electroless plating, chemical deterioration of the electrode does not occur in the electrode forming process.

FIG. 3 is an exploded perspective view of the piezoelectric resonance component according to the present invention, FIG. 4 is a partial sectional view of the piezoelectric resonance component according to the present invention shown in FIG. 3, and FIG. 5 is a plane on line A5-A5 in FIG. FIG. Reference numeral 1 is a case, reference numerals 21 to 2
Reference numeral 4 is a piezoelectric resonator, and reference numerals 31 to 34 are terminal plates.
The case 1 has an internal space 11. The internal space 11 is open on one side of the case 1. The opening is filled with the insulating sealing resin 6. A terminal lead-out hole 12 (see FIG. 1) is provided at the bottom of the case 1 on the side opposite to the side where the insulating sealing resin 6 is filled.

In each of the piezoelectric resonators 21 to 24, the electrode 210 has a Cu--Ni alloy, a Ni--Cr alloy, or a Cr-- electrode.
It is an element that uses a surface expansion vibration mode composed of at least one of Si alloys (see FIGS. 1 and 2). Referring to FIGS. 1 and 2, the piezoelectric ceramic body 200 is polarized so that an electrostrictive phenomenon occurs in a diagonal direction when an electric field is applied between the electrodes 210-210 on both surfaces. In the face-spreading vibration mode, a node is generated at the center of the plane of the piezoelectric ceramic body.

Each of the terminal plates 31 to 34 has a piezoelectric resonator 21 on a node formed on the surface of the piezoelectric resonator 21 to 24.
To 24, and the portions other than the contact points are piezoelectric resonators 21 to 21.
It is arranged away from the surface of 24. Terminal board 31
˜34 are made of, for example, a copper plate or a phosphor bronze plate having a plate thickness of about 0.1 mm. The terminal plate 31 has a structure in which a first contact piece 311 and a second contact piece 312 facing each other with a space therebetween are connected by a connecting piece 313. The first contact piece 311 and the second contact piece 312 respectively have protrusions 314 and 315 at their central portions. Protrusion 31
Reference numerals 4 and 315 form contact portions for nodes generated on the surfaces of the piezoelectric resonators 21 and 24. The terminal boards 32 to 34 have contact pieces 321 to 341 and contact pieces 321 to 341.
Protrusions 322 to 342 are provided on the surface of 42, respectively. The protrusions 322 to 342 also form contact portions with the nodes generated on the surfaces of the piezoelectric resonators 22 and 23. 323-3
43 is a terminal part.

Piezoelectric resonators 21-24 and terminal plates 31-3
4 are stacked so as to form a ladder circuit, and are arranged in the internal space 11 such that at least the periphery of the piezoelectric resonators 21 to 24 is spaced from the inner wall surface of the internal space 11. The arrangement relationship of the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34 for forming the ladder circuit will be described with reference to FIGS. 3 and 4. After inserting the terminal board 31 into the case 1, the piezoelectric resonator 21 and the terminal piece 3 are provided between the first contact piece 311 and the second contact piece 312 provided on the terminal board 31.
2, piezoelectric resonator 22, terminal piece 33, and piezoelectric resonator 23
Are inserted in this order. Next, after inserting the terminal plate 34 into the space between the second contact piece 312 of the terminal plate 31 and the inner wall surface of the case 1, the piezoelectric resonator is inserted between the terminal plate 34 and the second contact piece 312. Insert 24. The terminal portions 323 to 343 of the terminal pieces 32 to 34 are drawn out of the case 1 and bent in the same direction along the outer surface of the case 1. As a result, a planar mounting type piezoelectric resonance component is obtained. Reference numeral 7 in FIG. 4 is a sealing resin. Although not shown, the number, arrangement and size of the piezoelectric resonators are arbitrary. The same applies to the terminal board.

FIG. 6 is an electrical symbol diagram of the piezoelectric resonance component according to the present invention. The piezoelectric resonators 21 and 24 are series resonators, the piezoelectric resonators 22 and 23 are parallel resonators, and the terminal plate 3
A ladder connection circuit having 2 as an output terminal, the terminal plate 33 as a ground terminal, and the terminal plate 34 as an input terminal is obtained.

As described above, the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34 are laminated so as to form a ladder circuit, and at least the periphery of the piezoelectric resonators 21 to 24 is spaced from the inner wall surface of the internal space 11. Since they are arranged in the internal space 11 so as to be separated from each other, the ladder in which the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34 are incorporated in the case 1 without causing characteristic variations due to contact with the case 1 A piezoelectric resonant component of the type is obtained.

Each of the piezoelectric resonators 21 to 24 is an element utilizing the surface expansion vibration mode, and the terminal plates 31 to 31.
4 are in contact with each other at nodes generated on the surfaces of the piezoelectric resonators 21 to 24, and portions other than the contact point P are piezoelectric resonators 21 to 21.
Since it is separated from the surface of 24, the influence of the terminal plates 31 to 34 on the surface expansion vibration modes of the piezoelectric resonators 21 to 24 can be minimized.

Since the piezoelectric resonators 21 to 24 are composed of at least one of the electrodes 210 (see FIGS. 1 and 2) Cu--Ni alloy, Ni--Cr alloy or Cr--Si alloy, they are resistant to oxidation and resistance. Excellent sulphidation and corrosion resistance with no room for silver migration. Therefore, the electrodes 210 of the piezoelectric resonators 21 to 24 and the terminal plates 31 to 31
It is possible to obtain a highly reliable piezoelectric resonance component in which poor contact with 34 is unlikely to occur.

Further, when the electrode 210 made of at least one of Cu-Ni alloy, Ni-Cr alloy and Cr-Si alloy is used as a filter, the electrode 210 has an appropriate electric resistance value, so that it is effectively piezoelectric. Q of oscillator
Since the value is reduced, the group delay characteristic can be improved. Therefore, the group delay characteristic can be improved without using a resistor.

FIG. 7 is an exploded perspective view of the piezoelectric resonance component according to the present invention, and FIG. 8 is a partial sectional view of the piezoelectric resonance component according to the present invention shown in FIG. In the figure, the same reference numerals as those in FIGS. 3 to 5 denote the same components. In each of the piezoelectric resonators 21 to 24, the electrode 210 is an element that uses a surface expansion vibration mode in which the electrode 210 is composed of at least one of a Cu—Ni alloy, a Ni—Cr alloy, and a Cr—Si alloy (see FIGS. 1 and 2). Is. Piezoelectric resonator 21-2
4 of the conductive protrusions 4 on the nodes that occur on the surface.
It has 1 to 48. At least the surfaces of the conductive protrusions 41 to 48 are kept at the same potential as the electrode 210 (see FIGS. 1 and 2) provided on the surface of the piezoelectric ceramic body 200.
The illustrated conductive protrusions 41 to 48 are piezoelectric resonators 21 to 24.
A conductive resin attached to the surface of, for example, an epoxy-based conductive resin, which is applied and cured, is generally used.

Each of the terminal plates 31 to 34 is formed of a flat plate and is in contact with the conductive protrusions 41 to 48 at a contact point P,
The portions other than the contact points are arranged apart from the surfaces of the piezoelectric resonators 21 to 24.

As described above, since each of the terminal plates 31 to 34 is in contact with the conductive protrusions 41 to 48 provided on the piezoelectric resonators 21 to 24, the terminal plates 31 to 34 are provided with protrusions. No need. Therefore, the structure of the terminal plates 31 to 34 is simplified, the processing and assembly are facilitated, and the cost is reduced.

Since the terminal plates 31 to 34 are flat plates, their thickness is minimized. Moreover, in the case of the embodiment, the conductive protrusion 4
Since 1 to 48 are formed of a conductive resin, they can be made thinner than the protrusions provided on the conventional terminal board. Therefore, it is easy to reduce the thickness and size. Also,
The elasticity of the conductive resin can be used to generate the required spring pressure between the piezoelectric resonators 21-24 and the terminal plates 31-34.

Since the piezoelectric resonators 21 to 24 are composed of at least one of the electrodes 210 (see FIGS. 1 and 2) Cu--Ni alloy, Ni--Cr alloy or Cr--Si alloy, they are resistant to oxidation and resistance. Excellent sulphidation and corrosion resistance with no room for silver migration. Therefore, the electrodes 210 of the piezoelectric resonators 21 to 24 and the terminal plates 31 to 31
It is possible to obtain a highly reliable piezoelectric resonance component in which poor contact with 34 is unlikely to occur.

Further, when the electrode 210 made of at least one of Cu-Ni alloy, Ni-Cr alloy and Cr-Si alloy is used as a filter, the electrode 210 has an appropriate electric resistance value and thus is effectively piezoelectric. Q of oscillator
Since the value is reduced, the group delay characteristic can be improved. Therefore, the group delay characteristic can be improved without using a resistor.

FIG. 9 is a partial sectional front view showing another embodiment of the piezoelectric resonant component according to the present invention. Piezoelectric resonator 21-2
4 each has an electrode 210 of Cu-Ni alloy, Ni-
It is an element that uses a surface expansion vibration mode composed of at least one of a Cr alloy and a Cr-Si alloy (see FIGS. 1 and 2). The conductive protrusions 41 to 48 are formed by partially protruding the surfaces of the piezoelectric resonators 21 to 24. Therefore, it is not necessary to provide protrusions on the terminal plates 31 to 34. Therefore, the structure of the terminal plates 31 to 34 is simplified, the processing and assembly are facilitated, and the cost is reduced. Moreover, since the terminal plates 31 to 34 are flat plates, the thickness thereof is minimized. Moreover, the conductive protrusions 41 to 48 are formed by the piezoelectric resonators 21 to 24 themselves. For this reason, compared with the protrusion provided on the conventional terminal board, the entire structure becomes thinner.

Also in the case of this embodiment, the piezoelectric resonators 21 to 2 are
4 is excellent in oxidation resistance, sulfidation resistance and corrosion resistance because the electrode 210 (see FIGS. 1 and 2) is composed of at least one of Cu—Ni alloy, Ni—Cr alloy or Cr—Si alloy, There is no room for silver migration. Therefore, it is possible to obtain a highly reliable piezoelectric resonance component in which poor contact does not easily occur between the electrodes 210 of the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34.

Furthermore, when the electrode 210 made of at least one of Cu-Ni alloy, Ni-Cr alloy and Cr-Si alloy is used as a filter, the electrode 210 has an appropriate electric resistance value, so that it is effectively piezoelectric. Q of oscillator
Since the value is reduced, the group delay characteristic can be improved. Therefore, the group delay characteristic can be improved without using a resistor.

FIG. 10 is an enlarged sectional view showing a contact structure between a piezoelectric resonator and a terminal plate applicable to the piezoelectric resonance component shown in FIG. In each of the piezoelectric resonators 21 to 24, the electrode 210 is an element that uses a surface expansion vibration mode in which the electrode 210 is made of at least one of a Cu-Ni alloy, a Ni-Cr alloy, and a Cr-Si alloy (see FIGS. 1 and 2). Is. The terminal boards 31 to 34 have conductive protrusions 41 to 48.
A recess 8 for receiving the conductive protrusions 41 to 48 is provided at a portion contacting with.

With such a structure, the piezoelectric resonator 21
It is possible to prevent the positional deviation between .about.24 and the terminal plates 31 to 34. Therefore, it is possible to prevent fluctuations in resonance impedance and generation of unnecessary vibration modes, and obtain desired characteristics.
Further, it is possible to surely prevent the positional displacement and the incorrect arrangement of the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34 due to the vibration applied from the outside or the drop impact.

The piezoelectric resonators 21 to 24 are connected to the electrode 21.
0 (see FIG. 1 and FIG. 2) Since it is composed of at least one of Cu—Ni alloy, Ni—Cr alloy and Cr—Si alloy, it is excellent in oxidation resistance, sulfidation resistance and corrosion resistance and causes silver migration. There is no room.
Therefore, it is possible to obtain a highly reliable piezoelectric resonance component in which poor contact does not easily occur between the electrodes 210 of the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34. Furthermore, Cu-Ni alloy, Ni-
When the electrode 210 formed of at least one of a Cr alloy and a Cr-Si alloy is used as a filter, the electrode has an appropriate electric resistance value, which effectively lowers the Q value of the piezoelectric vibrator. Can be improved. Therefore, the group delay characteristic can be improved without using a resistor.

FIG. 11 is a partial sectional view showing still another embodiment of the piezoelectric resonant component according to the present invention. Piezoelectric resonator 21 to
In each of 24, the electrode 210 has a Cu-Ni alloy, Ni.
It is an element using a surface expansion vibration mode composed of at least one of a --Cr alloy and a Cr--Si alloy (see FIGS. 1 and 2). The conductive protrusions 41 to 48 are formed by gradually increasing the thickness of the piezoelectric resonators 21 to 24 toward the central node. Also in the case of this embodiment, the same operational effects as those of the embodiment shown in FIG. 9 are obtained.

FIG. 12 is a partial cross-sectional view showing still another embodiment of the piezoelectric resonance component according to the present invention, and FIG. 13 is A13 of FIG.
It is a cross-sectional view taken along the line A13. In each of the piezoelectric resonators 21 to 24, the electrode 210 is an element that uses a surface expansion vibration mode in which the electrode 210 is composed of at least one of a Cu—Ni alloy, a Ni—Cr alloy, and a Cr—Si alloy (see FIGS. 1 and 2). Is.

In this embodiment, the positioning means 91 is further used.
˜94. The positioning means 91 to 94 are elastic resin or expandable elastic resin filled in the positions corresponding to the nodes generated around the piezoelectric resonators 21 to 24. As an example of such a resin, a silicon-based resin can be cited. Since the illustrated piezoelectric resonators 21 to 24 have a rectangular shape, a total of four nodes are generated in the widthwise intermediate portion and the lengthwise intermediate portion of the piezoelectric resonators 21 to 24. The positioning means 91 to 94 are formed by applying an elastic resin or a foamable elastic resin to each of these nodes and curing it. It is desirable that the application width of the elastic resin or the expandable elastic resin be formed as narrow as possible within a range in which necessary mechanical strength can be secured.

Since the positioning means 91 to 94 are made of elastic resin or expandable elastic resin filled in the space, the elastic resin or expandable elastic resin is in close contact with the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34. , Piezoelectric resonators 21-24
Further, it is possible to surely prevent the positional displacement and the incorrect arrangement of the terminal boards 31 to 34.

Further, externally applied vibrations and drop impacts are absorbed by the elasticity of the elastic resin or the foamable elastic resin forming the positioning means 91 to 94, and the piezoelectric resonators 21 to.
It is possible to reliably prevent the positional deviation and the improper arrangement of the terminal 24 and the terminal boards 31 to 34.

The positioning means 91 to 94 are the piezoelectric resonator 2
Since the filling is performed at the positions corresponding to the nodes generated in the peripheral portions of 1 to 24, the vibration disturbance to the piezoelectric resonators 21 to 24 by the positioning means 91 to 94 can be minimized.

The piezoelectric resonators 21 to 24 are connected to the electrode 21.
0 (see FIG. 1 and FIG. 2) Since it is composed of at least one of Cu—Ni alloy, Ni—Cr alloy and Cr—Si alloy, it is excellent in oxidation resistance, sulfidation resistance and corrosion resistance and causes silver migration. There is no room.
Therefore, it is possible to obtain a highly reliable piezoelectric resonance component in which poor contact does not easily occur between the electrodes 210 of the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34. Furthermore, Cu-Ni alloy, Ni-
When the electrode 210 formed of at least one of a Cr alloy and a Cr-Si alloy is used as a filter, the electrode has an appropriate electric resistance value, which effectively lowers the Q value of the piezoelectric vibrator. Can be improved. Therefore, the group delay characteristic can be improved without using a resistor.

FIG. 14 is a partial cross-sectional view showing still another embodiment of the piezoelectric resonance component according to the present invention, and FIG. 15 is A15 of FIG.
It is a cross-sectional view taken along the line A15. In each of the piezoelectric resonators 21 to 24, the electrode 210 is an element that uses a surface expansion vibration mode in which the electrode 210 is composed of at least one of a Cu—Ni alloy, a Ni—Cr alloy, and a Cr—Si alloy (see FIGS. 1 and 2). Is.

The positioning means 91 to 93 are the piezoelectric resonator 2
1 to 24 are protrusions provided at intervals along the stacking direction of the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34, including the positions corresponding to the nodes generated in the peripheral portion. The positioning means 91 to 93 may be formed integrally with the case 1,
The case 1 may be a separate component and assembled at a predetermined position. Further, it is desirable that the width be formed as narrow as possible within a range in which necessary mechanical strength can be secured.

With the above structure, the positioning means 91-9
3, the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34
It is possible to surely prevent the positional deviation and the incorrect arrangement. Moreover,
Since the positioning means 91 to 94 are arranged at the positions corresponding to the nodes generated around the piezoelectric resonators 21 to 24, the piezoelectric resonators 21 to 2 by the positioning means 91 to 93 are arranged.
Vibration disturbance to 4 can be minimized.

Moreover, the piezoelectric resonators 21 to 24 are connected to the electrodes 2
10 (see FIGS. 1 and 2) is a Cu-Ni alloy, Ni-C
Since it is composed of at least one of r alloy and Cr-Si alloy, it has excellent oxidation resistance, sulfidation resistance and corrosion resistance, and there is no room for silver migration. Therefore, it is possible to obtain a highly reliable piezoelectric resonance component in which poor contact does not easily occur between the electrodes 210 of the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34. Furthermore, Cu-Ni alloy, N
When the electrode 210 formed of at least one of i-Cr alloy and Cr-Si alloy is used as a filter, since the electrode has an appropriate electric resistance value, it effectively lowers the Q value of the piezoelectric vibrator. The delay characteristic can be improved. Therefore, without using a resistor
The group delay characteristic can be improved.

In the embodiment, the case 1 has an opening on one end side when viewed in the widthwise direction, and the piezoelectric resonators 21 to 24.
The terminal plates 31 to 34 are adapted to be inserted into the case 1 through the openings. Under such a structure, the positioning means 91 to 93 are arranged on one end side in the lateral width direction on the side opposite to the opening side and on both sides in the longitudinal width direction. Therefore, by simply inserting the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34 into the case 1, the piezoelectric resonators 21 to
24 is subjected to the positioning action by the positioning means 91-93. Unlike the embodiment, the positioning means 91 to 93 can be arranged at one end side in the lateral width direction and the one end side in the longitudinal width direction opposite to the opening side. Also in this case, the piezoelectric resonators 21 to 24 can be positioned at predetermined positions in the case 1.

FIG. 16 is a partial sectional view showing still another embodiment of the piezoelectric resonance component according to the present invention, and FIG. 17 is A17 of FIG.
It is a cross-sectional view taken along the line A17. The piezoelectric resonators 21 to 24 are
The electrode 210 (see FIGS. 1 and 2) is a Cu—Ni alloy, N
It is composed of at least one of i-Cr alloy and Cr-Si alloy. In this embodiment, the piezoelectric resonator 21 among the plurality of piezoelectric resonators 21 to 24 is further provided.
The widths and 24 of the piezoelectric resonators 22 and 23 are smaller than those of the piezoelectric resonators 22 and 23 by dimensional differences d1 and d2. Also,
On the side facing the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34, step portions a and b having steps corresponding to the dimensional differences d1 and d2 in the horizontal width or the vertical width are provided. The steps a and b control the nodes generated on the surfaces of the piezoelectric resonators 21 to 24 in a direction in which the piezoelectric resonators coincide with each other. Positioning means 9
1 to 93 may be formed integrally with the case 1, or may be separate parts from the case 1 and assembled at predetermined positions. Further, it is desirable that the width be formed as narrow as possible within a range in which necessary mechanical strength can be secured.

Of the plurality of piezoelectric resonators 21 to 24 provided, the piezoelectric resonators 21 and 24 are smaller in lateral width and vertical width than the piezoelectric resonators 22 and 23 by the dimensional differences d1 and d2. Depending on the size of the children 21 to 24, high selectivity can be achieved and group delay characteristics can be improved.

The positioning means 91 to 93 are the piezoelectric resonator 2
1 to 24 and the terminal plates 31 to 34 are provided in the space between the case 1 and the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34 along the stacking direction of the piezoelectric resonators 21 to 24 and the terminal plate 31. Width difference of vertical width and vertical width d on the side facing
Since it has step portions a and b having steps corresponding to 1 and d2, the step portions a and b control the nodes generated on the surfaces of the piezoelectric resonators 21 to 24 in the same direction between the piezoelectric resonators. ,
Piezoelectric resonators 21 and 24 and piezoelectric resonator 2 having different sizes
The nodes generated on the surfaces of the piezoelectric resonators 21 to 24 can be reliably matched between 2 and 23. Therefore, it is possible to prevent fluctuations in resonance impedance and generation of unnecessary vibration modes, and obtain desired characteristics. Also,
Piezoelectric resonator 21 due to externally applied vibration or drop impact
It is possible to reliably prevent the positional deviation of the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34 and the improper arrangement by preventing the positional deviation of the to 24 and the terminal plates 31 to 34 by the positioning means 91 to 93.

Since the piezoelectric resonators 21 to 24 are composed of at least one of the electrodes 210 (see FIGS. 1 and 2) Cu--Ni alloy, Ni--Cr alloy or Cr--Si alloy, they are resistant to oxidation and resistance. Excellent sulphidation and corrosion resistance with no room for silver migration. Therefore, the electrodes 210 of the piezoelectric resonators 21 to 24 and the terminal plates 31 to 31
It is possible to obtain a highly reliable piezoelectric resonance component in which poor contact with 34 is unlikely to occur. Furthermore, when the electrode 210 made of at least one of Cu—Ni alloy, Ni—Cr alloy, and Cr—Si alloy is used as a filter, the electrode 210 has an appropriate electric resistance value, so that the electrode 210 is effectively used as a piezoelectric vibrator. Since the Q value is lowered, the group delay characteristic can be improved. Therefore, the group delay characteristic can be improved without using a resistor.

[0055]

As described above, according to the present invention, the following effects can be obtained. (A) It is possible to provide a highly reliable piezoelectric element having excellent oxidation resistance, sulfidation resistance, and corrosion resistance and having no room for silver migration, and a piezoelectric resonance component using the piezoelectric element having improved reliability. (B) It is possible to provide a piezoelectric element that does not cause chemical deterioration of the electrode in the electrode forming step and a piezoelectric resonance component using the piezoelectric element with improved reliability. (C) It is possible to provide a piezoelectric resonance component in which the electrodes have a resistance component and the group delay characteristics when used as a filter are improved without having a resistor. (D) without causing characteristic variations due to contact with the case,
It is possible to provide a ladder-type piezoelectric resonance component in which a piezoelectric resonator is incorporated in a case. (E) It is possible to provide a piezoelectric resonance component that can minimize the influence of the terminal plate on the surface expansion vibration mode of the piezoelectric resonator.

[Brief description of drawings]

FIG. 1 is a front view of a piezoelectric element according to the present invention.

FIG. 2 is a partially enlarged sectional view of the piezoelectric element shown in FIG.

FIG. 3 is an exploded perspective view of a piezoelectric resonance component according to the present invention.

FIG. 4 is a front partial cross-sectional view of a piezoelectric resonance component according to the present invention.

5 is a cross-sectional view taken along the line A5-A5 of FIG.

FIG. 6 is an electrical symbol diagram of the piezoelectric resonance component according to the present invention.

FIG. 7 is an exploded perspective view of a piezoelectric resonance component according to the present invention.

FIG. 8 is a partial front sectional view showing another embodiment of the piezoelectric resonance component according to the present invention.

FIG. 9 is a partial front sectional view showing another embodiment of the piezoelectric resonant component according to the present invention.

FIG. 10 is an enlarged cross-sectional view showing a contact structure between a piezoelectric resonator and a terminal plate applicable to the piezoelectric resonance component shown in FIG.

FIG. 11 is a partial front sectional view showing still another embodiment of the piezoelectric resonance component according to the present invention.

FIG. 12 is a partial front sectional view showing still another embodiment of the piezoelectric resonance component according to the present invention.

13 is a cross-sectional view taken along the line A13-A13 of FIG.

FIG. 14 is a partial front sectional view showing still another embodiment of the piezoelectric resonance component according to the present invention.

15 is a cross-sectional view taken along the line A15-A15 of FIG.

FIG. 16 is a partial front sectional view showing yet another embodiment of the piezoelectric resonant component according to the present invention.

17 is a cross-sectional view taken along the line A17-A17 of FIG.

[Explanation of symbols]

 200 Piezoelectric ceramic body 210 Electrode 1 Case 11 Internal space 21-24 Piezoelectric resonator 31-34 Terminal plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Tsushima Shima 13-1, Nihonbashi, Chuo-ku, Tokyo TDC Corporation (72) Inventor Takashi Yamamoto 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDC Within the corporation

Claims (2)

[Claims] 1. A piezoelectric element having electrodes on the surface of a piezoelectric ceramic body, wherein the electrodes are Cu--Ni alloy, Ni--Cr alloy or C
A piezoelectric element composed of at least one of r-Si alloys. 2. A piezoelectric resonance component including a case, a plurality of piezoelectric resonators, and a plurality of terminal plates, wherein the case has an internal space, and each of the piezoelectric resonators includes: Item 1. The piezoelectric element according to Item 1, which is an element that utilizes a surface expansion vibration mode, wherein each of the terminal plates comes into contact with the piezoelectric resonator on a node generated on a surface of the piezoelectric resonator, and A portion excluding a point is apart from the surface of the piezoelectric resonator, the piezoelectric resonator and the terminal plate are stacked to form a ladder circuit, and at least the periphery of the piezoelectric resonator is an inner wall surface of the internal space. A piezoelectric resonant component disposed in the internal space so as to be spaced apart from.