JPH06350384A - Piezoelectric element and piezoelectric resonance component - Google Patents

Abstract

PURPOSE:To simply and surely adjust a mechanical quality coefficient and a group delay characteristic or the like over a wide range by providing a non- electrode part in a face of surface electrodes of a piezoelectric ceramic raw material of a piezoelectric element utilizing a surface spread vibration mode. CONSTITUTION:The piezoelectric element 2 is an element utilizing the surface spread vibration mode and an electrode 210 is provided to a surface of a piezoelectric ceramic raw material 200 and a non-electrode part 220 is provided in a plane of the electrodes 210. The mechanical quality coefficient Qm of the piezoelectric element is adjusted depending on an occupied area by the non- electrode part 220 with respect to the area of the electrodes 210 and the occupied area of the non-electrode part 220 is adjusted by the size and its number or the like. Thus, the Qm and the group delay characteristic are surely adjusted over a wide range.

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 Piezoelectric resonance components used for ladder type ceramic filters and ceramic discriminators are
It is desirable that the delay characteristic in the pass frequency band be as flat as possible. As a means to improve group delay characteristics,
A technique using a piezoelectric material having a low mechanical quality factor Qm is known.

Another technique is disclosed in Japanese Patent Laid-Open No. 60-26.
Japanese Patent No. 4113 discloses a technique in which a damping resistor is connected in parallel to a portion corresponding to a series arm in an equivalent circuit, and a damping resistor is connected in series to a portion corresponding to a parallel arm.

[0004]

However, the conventional technique for improving the characteristics by using a piezoelectric material having a low mechanical quality factor Qm can cope with the necessity of adjusting the characteristics after commercialization. I can't.

Further, the technique described in the above-mentioned publicly known document is to improve the characteristic by using a damping resistor, and does not disclose the technique for improving the group delay characteristic by the piezoelectric element itself. The added damping resistance causes an increase in the number of parts and hinders miniaturization.

Therefore, an object of the present invention is to provide a piezoelectric element capable of easily and reliably adjusting the mechanical quality factor Qm, the group delay characteristic, etc., and a piezoelectric resonance component using the same. .

Another object of the present invention is to provide a piezoelectric element capable of improving the mechanical quality factor Qm and group delay characteristic by the element itself, and a piezoelectric resonance component using the same.

[0008]

In order to solve the above-mentioned problems, the present invention provides a piezoelectric element having an electrode on the surface of a piezoelectric ceramic body and utilizing a surface-spreading vibration mode. Has a non-electrode portion.

Further, the piezoelectric resonance component according to the present invention is a piezoelectric resonance component including a case, a plurality of piezoelectric resonators, and a plurality of terminal plates, and the case has an internal space, Each of the piezoelectric resonators is the above-described piezoelectric element according to the present invention, and each of the terminal plates is in contact with the piezoelectric resonator on a node generated on the surface of the piezoelectric resonator, excluding a contact point. The portion is separated from the surface of the piezoelectric resonator, the piezoelectric resonator and the terminal plate are stacked so as to form a ladder circuit, and are arranged in the internal space.

[0010]

The piezoelectric element according to the present invention is a piezoelectric element that utilizes the surface-spreading vibration mode, and is therefore suitable for forming a ladder-type ceramic filter, a ceramic discriminator, or the like.

Moreover, since the piezoelectric element according to the present invention has the electrode on the surface of the piezoelectric ceramic body and the non-electrode portion in the surface of the electrode, the piezoelectric element according to the area occupied by the non-electrode portion with respect to the electrode area The mechanical quality factor Qm can be adjusted. The non-electrode portion can be formed after the piezoelectric element is commercialized. Moreover, the occupied area of the non-electrode portion, which is a factor that determines the mechanical quality factor Qm, can be easily and reliably adjusted according to the size, number, etc. of the non-electrode portions. Therefore, the mechanical quality factor Qm and the group delay characteristic can be adjusted in a wide range easily and reliably.

Further, in the piezoelectric element according to the present invention, the mechanical quality factor Q is increased by the non-electrode portion provided in the surface of the electrode.
Those that adjust m to improve the group delay characteristic, in other words,
The element itself improves the group delay characteristic. No external component is required unlike the prior art in which the characteristics are improved by using a damping resistor. For this reason, the number of parts is not increased, and miniaturization can be easily accommodated.

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 so as to form a ladder circuit, and a ladder-type piezoelectric resonance component incorporated in a case is obtained.

Each of the piezoelectric resonators is the above-described piezoelectric element according to the present invention. Therefore, the mechanical quality factor Qm and the group delay characteristic can be adjusted in a wide range in a simple and reliable manner. In addition, the number of parts is not increased, and miniaturization can be easily accommodated.

[0016]

1 is a plan view of a piezoelectric element according to the present invention, and FIG.
FIG. 2 is a partially enlarged sectional view of the piezoelectric element shown in FIG. The piezoelectric element 2 is an element that uses a surface-spreading vibration mode, and has an electrode 210 on the surface of the piezoelectric ceramic body 200.
Since it is an element that utilizes the surface-spreading vibration mode, the piezoelectric ceramic body 200 is polarized so as to generate an electrostrictive phenomenon in a diagonal direction when an electric field is applied between the electrodes 210-210 on both surfaces. In the surface expansion vibration mode, a node is generated at the center of the plane of the piezoelectric ceramic body 200. The piezoelectric element utilizing the surface expansion vibration mode is suitable for forming a ladder type ceramic filter, a ceramic discriminator, or the like.

A non-electrode portion 220 is provided in the surface of the electrode 210. The mechanical quality factor Qm of this piezoelectric element is
It can be adjusted according to the occupied area of the non-electrode portion 220 with respect to the area of 0. The occupied area of the non-electrode portion 220, which is a factor that determines the mechanical quality factor Qm, can be easily and surely adjusted according to the size, number and the like. Therefore, the mechanical quality factor Qm and the group delay characteristic can be adjusted in a wide range easily and reliably. The shape of the non-electrode portion 220 may be either circular or rectangular.

Further, the piezoelectric element according to the present invention has an electrode 21.
The non-electrode portion 220 provided in the plane of 0 adjusts the mechanical quality factor Qm to improve the group delay characteristic,
In other words, the element itself improves the group delay characteristic. The characteristic is not improved by using the damping resistor. For this reason, the number of parts is not increased, and miniaturization can be easily accommodated.

The electrode 210 is made of Cu-Ni alloy, Ni-C.
It is desirable to be composed of at least one of r alloy and Cr-Si alloy. The electrode 210 made of at least one of a Cu—Ni alloy, a Ni—Cr alloy, and a Cr—Si alloy 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 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.

The piezoelectric element shown in FIG. 1 shows an example suitable for being used as a series element when forming a ladder type ceramic filter. The electrode 210 has a piezoelectric ceramic body 20 such that a ring-shaped non-electrode forming region is formed around the electrode 210.
It is provided at the center of 0.

FIG. 3 shows an example suitable for use as a parallel element in constructing a ladder type ceramic filter. The electrode 210 is provided on almost the entire surface of the piezoelectric ceramic body 200. The non-electrode portion 220 is the electrode 210
Widely distributed in the plane of.

Next, a specific example of a piezoelectric resonance component using the above piezoelectric element will be described.

FIG. 4 is an exploded perspective view of the piezoelectric resonance component according to the present invention, FIG. 5 is a partial sectional view of the piezoelectric resonance component according to the present invention shown in FIG. 4, and FIG. 6 is a plane on line A6-A6 of 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. 4) is provided at the bottom of the case 1 on the side opposite to the side where the insulating sealing resin 6 is filled.

Each of the piezoelectric resonators 21 to 24 is shown in FIG.
3 is a piezoelectric element shown and described in FIG. 3, that is, a piezoelectric element having an electrode 210 on the surface of the piezoelectric ceramic body 200 and utilizing a surface expansion vibration mode, in which a large number of non-electrodes are formed on the surface of the electrode 210. It has an electrode portion 220.

Each of the terminal plates 31 to 34 has a piezoelectric resonator 21 on a node formed on the surface of the piezoelectric resonators 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. Although not shown in the figure, instead of a metal plate such as a copper plate or a phosphor bronze plate, a flexible polymer film having a conductor pattern on the surface is used to form the terminal plates 31 to 31.
4 can also be configured.

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. Reference numeral 7 in FIG. 5 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. 7 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. The piezoelectric resonators 21 and 24 used as the series resonator are shown in FIG.
The piezoelectric resonators 22 and 23 used as parallel resonators shown in FIG. 2 are the piezoelectric elements shown in FIG.

As described above, since the piezoelectric resonance component according to the present invention uses the piezoelectric element according to the present invention shown in FIGS. 1 to 3 as the piezoelectric resonators 21 to 24, it has a group delay characteristic. Adjustable over a wide range with ease and reliability. Electrode 2
Since the mechanical quality factor Qm is adjusted by the non-electrode portion 220 provided in the plane of 10, the number of parts is not increased unlike the case where the characteristic is improved by using the damping resistance. It can easily be made smaller.

Further, the piezoelectric resonators 21 to 24 and the terminal plate 3
The piezoelectric resonators 21 to 2 are laminated so as to form a ladder circuit and arranged in the internal space 11.
Thus, a ladder-type piezoelectric resonance component in which 4 and the terminal plates 31 to 34 are incorporated in the case 1 can be 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.

FIG. 8 is a partial sectional view of the piezoelectric resonance component according to the present invention. In the figure, the same reference numerals as those in FIGS. 5 and 6 denote the same components. Piezoelectric resonator 21
1 to 3, each is a piezoelectric element having an electrode 210 on the surface of the piezoelectric ceramic body 200 and utilizing a surface expansion vibration mode, as shown in FIGS.
The electrode 210 has a non-electrode portion 220 in the surface thereof. Furthermore,
The piezoelectric resonators 21 to 24 have conductive adhesive layers 41 to 48 on the nodes formed on the surfaces of the piezoelectric resonators 21 to 24. The conductive adhesive layers 41 to 48 are the piezoelectric resonators 21 to
24 or the terminal plates 31 to 34, or a conductive resin such as an epoxy-based conductive resin or solder that is attached so as to bond the two.

Each of the terminal plates 31 to 34 is formed of a flat plate and contacts the conductive adhesive layers 41 to 48 at a contact point P, and the portions other than the contact points are separated from the surfaces of the piezoelectric resonators 21 to 24. It is located in.

As described above, since the piezoelectric element according to the present invention is used as the piezoelectric resonators 21 to 24, the group delay characteristic can be adjusted in a wide range easily and surely. Moreover,
Since the mechanical quality factor Qm is adjusted by the non-electrode portion 220 provided in the surface of the electrode 210, unlike the case where the characteristics are improved by using the damping resistance,
No increase in the number of parts is required, and miniaturization can be easily accommodated.

Further, the piezoelectric resonators 21 to 24 and the terminal plate 3
Since the conductive adhesive layers 41 to 48 are provided between 1 to 34, 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,
It is easy to process and assemble, and the cost is low.

Since the terminal plates 31 to 34 are flat plates, their thickness is minimized. Moreover, in the case of the embodiment, since the conductive adhesive layers 41 to 48 are formed of the conductive resin,
It can be made thinner than the protrusion provided on the conventional terminal board. Therefore, it is easy to reduce the thickness and size. In addition, the elasticity of the conductive resin is used to make the piezoelectric resonators 21 to 2
4 and the terminal plates 31 to 34 can generate a necessary spring pressure.

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 has electrodes 21 on the surface of the piezoelectric ceramic body 200.
It is a piezoelectric element having 0 and utilizing a surface expansion vibration mode, and has a non-electrode portion 220 in the surface of an electrode 210.
In addition, the piezoelectric resonators 21 to 24 have conductive protrusions 41 to 48 formed by protruding the piezoelectric ceramic body 200 at the center.
The terminal plates 31 to 34 are flat plates.

Also in the case of this embodiment, the piezoelectric resonators 21 to 2 are
Since the piezoelectric element according to the present invention is used as 4, the group delay characteristic can be adjusted in a wide range easily and surely. Moreover, the non-electrode portion 220 provided in the surface of the electrode 210
Since the mechanical quality coefficient Qm is adjusted by the above, unlike the case where the characteristics are improved by using the damping resistance, the number of parts is not increased and the miniaturization can be easily coped with.

Further, the piezoelectric resonators 21 to 24 have conductive protrusions 41 to 4 formed by protruding the piezoelectric ceramic body 200 at the center.
It is not necessary to provide the projections on the terminal plates 31 to 34 because the terminal plates 31 to 34 are provided. Therefore, the structure of the terminal plates 31 to 34 is simplified, the processing and assembly are facilitated, and the cost is reduced.

FIG. 10 is an enlarged sectional view showing a contact structure between a piezoelectric resonator and a terminal plate applicable to the piezoelectric resonant component shown in FIG. The terminal plates 31 to 34 are the conductive protrusions 4
The recesses 8 that receive the conductive protrusions 41 to 48 are provided in the portions that contact the 1 to 48.

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.

FIG. 11 is a partial sectional view showing still another embodiment of the piezoelectric resonance component according to the present invention, and FIG. 12 is A12 of FIG.
It is a cross-sectional view taken along the line A12. Each of the piezoelectric resonators 21 to 24 is a piezoelectric element that has an electrode 210 on the surface of the piezoelectric ceramic body 200 and uses a surface expansion vibration mode.
The electrode 210 has a non-electrode portion 220 in the surface thereof. This embodiment further includes positioning means 91-94. 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, the piezoelectric resonators 21 to 24 have an intermediate portion in the width direction and an intermediate portion in the length direction.
A total of 4 nodes are generated. Positioning means 91-94
Is 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.

Also in this embodiment, the piezoelectric resonators 21 to 21
Since the piezoelectric element according to the present invention is used as 24, the group delay characteristics can be adjusted in a wide range easily and reliably.
Moreover, the non-electrode portion 22 provided in the surface of the electrode 210
Since the mechanical quality factor Qm is adjusted by 0, unlike the case where the characteristics are improved by using the damping resistance, the number of parts is not increased and the miniaturization can be easily dealt with.

Further, since the positioning means 91 to 94 are made of elastic resin or expandable elastic resin filled in the space, the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34 are not made of elastic resin or expandable elastic resin. Close and piezoelectric resonator 21
It is possible to surely prevent the positional deviation and the improper arrangement of the terminals 24 to 24 and the terminal boards 31 to 34.

Further, externally applied vibration and drop impact are absorbed by the elasticity of the elastic resin or foaming elastic resin which constitutes the positioning means 91-94, and the piezoelectric resonators 21-94.
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.

FIG. 13 is a partial cross-sectional view showing still another embodiment of the piezoelectric resonance component according to the present invention, and FIG. 14 is A14 of FIG.
It is a cross-sectional view taken along the line A14. Each of the piezoelectric resonators 21 to 24 is a piezoelectric element that has an electrode 210 on the surface of the piezoelectric ceramic body 200 and uses a surface expansion vibration mode. The piezoelectric ceramic body 200 includes a non-electrode portion 22 within the surface of the electrode 210.
Has 0. The positioning means 91 to 93 are the piezoelectric resonators 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.

Also in the case of this embodiment, the piezoelectric resonators 21 to 2 are
Since the piezoelectric element according to the present invention is used as 4, the group delay characteristic can be adjusted in a wide range easily and surely. Moreover, the non-electrode portion 220 provided in the surface of the electrode 210
Since the mechanical quality coefficient Qm is adjusted by the above, unlike the case where the characteristics are improved by using the damping resistance, the number of parts is not increased and the miniaturization can be easily coped with.

Further, the positioning means 91 to 93 can surely prevent the positional displacement and the incorrect arrangement of the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34. Moreover, since the positioning means 91 to 94 are arranged at the positions corresponding to the nodes generated in the peripheral portions of the piezoelectric resonators 21 to 24, the vibration disturbance to the piezoelectric resonators 21 to 24 by the positioning means 91 to 93 is minimized. Can be

FIG. 15 is a partial cross-sectional view showing still another embodiment of the piezoelectric resonance component according to the present invention, and FIG. 16 is A16 of FIG.
It is a cross-sectional view taken along the line A16. Each of the piezoelectric resonators 21 to 24 is a piezoelectric element that has an electrode 210 on the surface of the piezoelectric ceramic body 200 and uses a surface expansion vibration mode.
The electrode 210 has a non-electrode portion 220 in the surface thereof.

Further, a plurality of piezoelectric resonators 21 to 2 are provided.
4, the piezoelectric resonators 21 and 24 are smaller in lateral width and vertical width than those of the piezoelectric resonators 22 and 23 by dimensional differences d1 and d2. Further, 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 of 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. The positioning means 91 to 93 may be formed in the same body as the case 1, or may be a component separate from the case 1 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.

Also in this embodiment, the piezoelectric resonators 21 to 2 are
Since the piezoelectric element according to the present invention is used as 4, the group delay characteristic can be adjusted in a wide range easily and surely. Moreover, the non-electrode portion 220 provided in the surface of the electrode 210
Since the mechanical quality coefficient Qm is adjusted by the above, unlike the case where the characteristics are improved by using the damping resistance, the number of parts is not increased and the miniaturization can be easily coped with. Plural piezoelectric resonators 21 to 24
Among them, the piezoelectric resonators 21 and 24 are smaller in lateral width and vertical width than those of the piezoelectric resonators 22 and 23 by the dimensional differences d1 and d2, so that the piezoelectric resonators 21 to 24 have a high selectivity. And group delay characteristics can be improved.

Further, the positioning means 91 to 93 are arranged along the stacking direction of the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34, and the case 1, the piezoelectric resonators 21 to 24 and the terminal plates 31 to 31.
The piezoelectric resonators 21 to 24 are provided in the space between the
And step portions a and b having steps corresponding to the lateral and vertical dimension differences d1 and d2 on the side facing the terminal plates 31 to 34, and the surface of the piezoelectric resonators 21 to 24 is formed by the step portions a and b. Since the nodes generated above are controlled in the same direction between the piezoelectric resonators, between the piezoelectric resonators 21 and 24 and the piezoelectric resonators 22 and 23 having different sizes, the piezoelectric resonators 21 to 2 are arranged.
The nodes generated on the surface of No. 4 can be surely matched. Therefore, it is possible to prevent fluctuations in resonance impedance and generation of unnecessary vibration modes, and obtain desired characteristics.
Further, the positioning means 91 to 93 prevent the piezoelectric resonators 21 to 24 and the terminal plates 31 to 34 from being displaced due to vibration applied from the outside or a drop impact, 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.

[0054]

As described above, according to the present invention, the following effects can be obtained. (A) A wide range of mechanical quality factors Qm and group delay characteristics,
It is possible to provide a piezoelectric element that can be adjusted easily and reliably and a piezoelectric resonance component using the same. (B) It is possible to provide a piezoelectric element capable of improving group delay characteristics by the element itself and a piezoelectric resonance component using the same.

[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 a plan view showing another embodiment of the piezoelectric element according to the present invention.

FIG. 4 is an exploded perspective view of a piezoelectric resonance component according to the present invention.

FIG. 5 is a front partial cross-sectional view of the piezoelectric resonance component according to the present invention.

6 is a cross-sectional view taken along the line A6-A6 of FIG.

FIG. 7 is an electrical symbol diagram of the 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.

12 is a cross-sectional view taken along the line A12-A12 of FIG.

FIG. 13 is a partial front sectional view showing still another embodiment of the piezoelectric resonant component according to the present invention.

14 is a cross-sectional view taken along the line A14-A14 of FIG.

FIG. 15 is a front partial cross-sectional view showing still another embodiment of the piezoelectric resonance component according to the present invention.

16 is a cross-sectional view taken along the line A16-A16 of FIG.

[Explanation of symbols]

 200 Piezoelectric ceramic body 210 Electrode 220 Non-electrode part 1 Case 11 Internal space 21-24 Piezoelectric resonator 31-34 Terminal board

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takashi Yamamoto 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDC Corporation (72) Inventor Yasunobu Oikawa 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDC Incorporated (72) Inventor Minoru Takatani 1-13-1 Nihonbashi, Chuo-ku, Tokyo

Claims (3)

[Claims] 1. A piezoelectric element having an electrode on the surface of a piezoelectric ceramic body and utilizing a surface expansion vibration mode, the piezoelectric element having a non-electrode portion in the surface of the electrode. 2. The piezoelectric element according to claim 1, wherein the non-electrode portion has an area sufficiently smaller than the electrode area and is provided in large numbers. 3. 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 comprises: Item 3. The piezoelectric element according to Item 1 or 2, 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 other than a contact point is the piezoelectric element. A piezo-resonant component that is separated from the surface of the resonator, the piezoelectric resonator and the terminal plate are stacked so as to form a ladder circuit, and are arranged in the internal space.