JPH05191198A - Piezoelectric component - Google Patents

Abstract

PURPOSE:To provide a piezoelectric component capable of suppressing unrequired vibration. CONSTITUTION:The piezoelectric component 10 includes a rectangular piezoelectric substrate 12, and vibrating electrodes 14a, 14b are formed on the main planes on one side and the other side of the piezoelectric substrate 12, respectively. The peripheral part of the piezoelectric substrate 12 is adhered with the peripheral parts of insulating substrates 18a, 18b with adhesives 22a, 22b, and it is sandwiched between the insulating substrates 18a and 18b. Recessed parts 24a, 24b are formed at both terminal parts of the insulating substrates 18a, 18b, respectively. Soldering 26a, 26b are embedded in the recessed parts 24a, 24b. Also, the vibrating electrodes 14a and 14b are connected to external electrodes 30a, 30b via draw-out electrodes 16a, 16b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric component, and more particularly to a piezoelectric component having a piezoelectric substrate and used for, for example, a discriminator, a trap or a filter.

[0002]

13 (A) is a perspective view showing an example of a conventional piezoelectric component, and FIG. 13 (B) is a line X in FIG. 13 (A).
It is a sectional view solution figure in IIIB-XIIIB. The piezoelectric component 1 includes a rectangular piezoelectric substrate 2 made of a piezoelectric material such as PZT. The vibrating electrodes 3a and 3b are formed at the centers of the one main surface and the other main surface of the piezoelectric substrate 2, respectively. Further, on one main surface of the piezoelectric substrate 2, one end of the vibrating electrode 3 in the longitudinal direction thereof is provided.
A lead electrode (not shown) is formed extending to a. Further, a lead electrode (not shown) is formed on the other main surface of the piezoelectric substrate 2 so as to extend from the other end portion in the longitudinal direction thereof to the other vibrating electrode 3b. The piezoelectric substrate 2 is held by two insulating substrates 4a and 4b made of ceramic such as alumina. In this case, the two piezoelectric substrates 4a and 4b are respectively attached to the adhesive 5 on all peripheral portions of the one main surface and the other main surface of the piezoelectric substrate 2.
Then, the peripheral portion of the piezoelectric substrate 2 is sandwiched between the two piezoelectric substrates 4a and 4b via the adhesive 5. External electrodes 6a and 6b are formed on one end and the other end of the piezoelectric component 1 in the longitudinal direction by sputtering. These external electrodes 6a and 6b are electrically connected to the vibrating electrodes 3a and 3b via the above-mentioned two extraction electrodes, respectively.

[0003]

This conventional piezoelectric component 1
Then, in the piezoelectric substrate 2, vibrations such as contour vibrations and width vibrations in the long and short sides are generated in addition to the thickness longitudinal vibration and the thickness shearing vibration which are main. Further, all peripheral portions of the piezoelectric substrate 2 are sandwiched by the piezoelectric substrates 4a and 4b with the adhesive 5 interposed therebetween. Therefore, in this piezoelectric component 1, the main thickness longitudinal vibration and thickness shear vibration are leaked to the insulating substrates 4a and 4b via the adhesive 5, and the harmonics of the contour vibration and the width vibration are transmitted via the adhesive 5. And resonate with the insulating substrates 4a and 4b, causing unnecessary vibration. Therefore, such a conventional piezoelectric component has a large distortion rate when it is used as a discriminator, and when it is used as a trap, the group delay time characteristic on the low frequency side is found, and when it is used as a filter, the high frequency side is obtained. Has a large spurious and is not preferable in terms of electrical characteristics.

Therefore, a main object of the present invention is to provide a piezoelectric component capable of suppressing unnecessary vibration.

[0005]

The present invention includes a piezoelectric substrate having a vibrating electrode on its main surface and an insulating substrate for sandwiching the piezoelectric substrate, wherein a recess is provided at an end of the insulating substrate. It is a piezoelectric component that is formed and further has a filling material filled in the concave portion of the insulating substrate.

In this piezoelectric component, the extraction electrode extending from the vibrating electrode is formed on the main surface of the piezoelectric substrate, the external electrode is formed on the surface of the insulating substrate, and the extraction electrode and the external electrode are formed by using metal as a filler. You may electrically connect with an electrode with a filler.

[0007]

Function: The piezoelectric substrate is sandwiched between the insulating substrates. Also,
Unnecessary vibration is suppressed by the mass load of the filling material with which the concave portion of the insulating substrate is filled.

[0008]

According to the present invention, a piezoelectric component capable of suppressing unnecessary vibration can be obtained. Therefore, in the piezoelectric component according to the present invention, if it is used as a discriminator, the distortion rate caused by unnecessary vibration is improved, and if it is used as a trap, only the group delay time characteristic on the low frequency side caused by unnecessary vibration is suppressed. If it is used for a filter, spurious on the high frequency side caused by unnecessary vibration is reduced.

When metal is used as the filling material and the extraction electrode and the external electrode are electrically connected by the filling material, the reliability of the connection between the vibrating electrode and the external electrode is improved.

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

[0011]

1 (A) is a perspective view showing an embodiment of the present invention, FIG. 1 (B) is a sectional view taken along line IB-IB in FIG. 1 (A), and FIG. ) Is the line I in FIG.
It is sectional drawing solution figure in C-IC. 2 is shown in FIG.
2 is an exploded perspective view of the embodiment shown in FIG.

The piezoelectric component 10 of this embodiment is, for example, P
It includes a rectangular piezoelectric substrate 12 made of a piezoelectric material such as ZT. The piezoelectric substrate 12 is mainly polarized in the thickness direction in order to generate thickness longitudinal vibration. In addition,
The piezoelectric substrate 12 may be polarized in its longitudinal direction or its width direction mainly to cause thickness shear vibration.

In the center of one main surface and the other main surface of the piezoelectric substrate 12, for example, circular vibrating electrodes 14a and 14 are provided.
b are formed respectively. Furthermore, for example, T-shaped lead-out electrodes 16a and 16b are formed on one main surface and the other main surface of the piezoelectric substrate 12, respectively. In this case, one extraction electrode 16a is formed so as to extend from one vibration electrode 14a to one end in the longitudinal direction of the piezoelectric substrate 12, and the other extraction electrode 16b is formed on the other vibration electrode 14a.
It is formed by extending from b to the other end of the piezoelectric substrate 12 in the longitudinal direction.

The piezoelectric substrate 12 has its peripheral portion sandwiched between two insulator substrates 18a and 18b made of ceramic such as alumina. That is, one insulator substrate 18a is formed so that its length and width are substantially the same as the length and width of the piezoelectric substrate 12, and the indented portion 20a is formed at the center of its one main surface. Then, the insulating substrate 18a is bonded at its peripheral portion on one main surface to the peripheral portion on one main surface of the piezoelectric substrate 12 with an adhesive 22a. Similarly, the length and width of the other insulating substrate 18b are also formed to have substantially the same dimensions as the length and width of the piezoelectric substrate 12, and a recess 20b is formed at the center of one main surface thereof. Then, the peripheral portion of the insulating substrate 18b is bonded to the peripheral portion of the other main surface of the piezoelectric substrate 12 with an adhesive. Therefore, the insulator substrates 18a and 18b do not contact the vibrating electrodes 14a and 14b on the main surface of the piezoelectric substrate 12 and do not interfere with the vibration of the vibrating electrodes 14a and 14b.

On one insulating substrate 18a, recesses 24a are formed at both ends of the center of one main surface in the longitudinal direction. Then, for example, solder 26a is embedded as a filler in each of the recesses 24a. Similarly, the other insulating substrate 18b is also provided with recesses 24b at both ends at the center in the longitudinal direction of the one main surface thereof. Solder 26b, for example, is embedded as a filler in each of the recesses 24b. The solders 26a and 26b as the fillers are for suppressing unnecessary vibration.

Further, in this piezoelectric component 10, the external electrodes 28a and 28 are provided at both ends at the center in the longitudinal direction.
b thus surrounds the set of solders 26a and 26b and is thus respectively formed by sputtering.
These external electrodes 28a and 28b are for preventing unnecessary vibration from being reflected on the side surface of the piezoelectric component 10 and causing slump in the main vibration.

Further, in this piezoelectric component 10, external electrodes 30a and 30b for input / output are formed on both ends in the longitudinal direction by sputtering. The external electrodes 30a and 30b are electrically connected to the extraction electrodes 16a and 16b, respectively.

In this piezoelectric component 10, unnecessary vibration is suppressed by the mass load of the solders 26a and 26b as fillers provided at both ends in the center in the longitudinal direction. That is, if this piezoelectric component 10 is used as a discriminator, unnecessary vibration due to leakage of vibration mainly to the insulating substrate and unnecessary vibration due to resonance between the insulating substrate and harmonics of contour vibration and width vibration are suppressed. As a result, the strain is eliminated and the strain rate is reduced. If this piezoelectric component 10 is used for a filter, similarly, unnecessary vibration due to leakage of main vibration and resonance of higher harmonics is suppressed,
Spurious on the high frequency side is reduced. Further, when the piezoelectric component 10 is used as a trap, unnecessary vibration due to resonance of harmonics of contour vibration and width vibration is suppressed, thereby suppressing drooling of the group delay time characteristic on the low frequency side at 1 to 3 MHz, for example. Be done.

FIG. 3 (A) is a perspective view showing another embodiment of the present invention, and FIG. 3 (B) is a line IIIB-- in FIG. 3 (A).
FIG. 3C is a schematic cross-sectional view taken along line IIIB in FIG.
It is a sectional view solution figure in the line IIIC-IIIC of (A). 4 is an exploded perspective view of the embodiment shown in FIG. This embodiment differs from the embodiment shown in FIG. 1 in the following points.

That is, in this embodiment, the piezoelectric substrate 1
Two circular vibrating electrodes 14a and 14b are formed on one main surface of the two at intervals in the longitudinal direction. For example, T-shaped lead-out electrodes 16a and 16b are formed extending from the vibrating electrodes 14a and 14b to one end and the other end in the longitudinal direction of the piezoelectric substrate 12, respectively.

Further, on the other main surface of the piezoelectric substrate 12,
In particular, as shown in FIG. 5, two vibrating electrodes 14c and 1
4d is formed so as to face the vibrating electrodes 14a and 14b described above. Further, a third extraction electrode 16c is formed on the other main surface of the piezoelectric substrate 12 at the center in the longitudinal direction. Further, the extraction electrode 16c is
It is formed so as to extend to the two vibrating electrodes 14c and 14d.

Further, dents 20a and 20b are provided at the central portions of the insulating substrates 18a and 18b in the longitudinal direction.
Is not formed. That is, the recessed portions 20a are formed at intervals in the longitudinal direction of the insulating substrate 18a. Similarly, the recessed portions 20b are also formed at intervals in the longitudinal direction of the insulating substrate 18b. Also, the central portions of the insulating substrates 18a and 18b in the longitudinal direction also include the piezoelectric substrate 1.
2 to the one main surface and the other main surface of the adhesive 22a and 2
At 2b, they are bonded together.

Further, recesses 24a are formed in the one main surface of the one insulating substrate 18a at both ends in the width direction corresponding to the recesses 20a. Solder 26a, for example, is embedded as a filling material in these recesses 24a. Similarly, recesses 24b are formed on the one main surface of the other insulator substrate 18a at both ends in the width direction corresponding to the recesses 20b. Solder 26b, for example, is also embedded as a filling material in these recesses 24b.

Further, in the piezoelectric component 10 of this embodiment,
An external electrode 28a for preventing reflection of unnecessary vibration by surrounding one set of solders 26a and 26b at one end and the other end in the width direction, respectively.
And 28b are respectively formed.

Further, in the piezoelectric component 10 of this embodiment, the external electrodes 30a, 30b and 30c for input and output are sputtered so as to circulate one end, the other end and the central part in the longitudinal direction thereof. Formed by. These external electrodes 30a to 30c are electrically connected to the extraction electrodes 16a to 16c, respectively.

Therefore, the piezoelectric component 10 of the embodiment shown in FIG. 3 has the circuit configuration shown in FIG.

Also in the embodiment shown in FIG. 3, unnecessary vibrations are suppressed by the solders 26a and 26b as fillers provided at both ends in the width direction. for that reason,
When the piezoelectric component 10 of this embodiment is used as a discriminator, distortion is eliminated and the distortion rate is reduced, and when it is used as a filter, spurious on the high frequency side is reduced,
If it is used as a trap, only the group delay time characteristic on the low frequency side can be suppressed. In the piezoelectric component 10 of this embodiment, the piezoelectric substrate 12 is polarized in the thickness direction in order to use it in the discriminator or filter, and in order to use it in the trap, the piezoelectric substrate 1 is used.
2 is polarized in its longitudinal or width direction.

Further, in the embodiment shown in FIG. 3, for example, a piezoelectric substrate having electrodes of other types as shown in FIGS. 7 (A) and 7 (B) may be used.

FIG. 7A is a plan view showing a piezoelectric substrate on which another type of electrode is formed, and FIG. 7B is a bottom view thereof. That is, on one main surface of the piezoelectric substrate 12, one set of vibrating electrodes 14a1 and 14 is provided on one end side thereof.
a2 is formed with a space, and a pair of vibrating electrodes 14b1 and 14b2 are formed with a space on the other end side. Further, a capacitor electrode 15a is formed at the center of one main surface of the piezoelectric substrate 12. In this case, the capacitor electrode 15a has two vibrating electrodes 14a1 and 14b.
1 is formed to extend. Further, for example, T-shaped lead-out electrodes 16a and 16b are formed extending from the other vibrating electrodes 14a2 and 14b2 to one end and the other end in the longitudinal direction of the piezoelectric substrate 12, respectively.

On the other main surface of the piezoelectric substrate 12, a vibrating electrode 14a3 is formed so as to oppose a set of vibrating electrodes 14a1 and 14a2, and the other vibrating electrode 14 is formed.
b3 is formed so as to face the other pair of vibrating electrodes 14b1 and 14b2. Further, a capacitor electrode 15b is formed in the center of the other main surface of the piezoelectric substrate 12 so as to face the above-mentioned capacitor electrode 15a. In this case, the capacitor electrode 15b has two vibrating electrodes 14a.
3 and 14b3.

The piezoelectric substrate 12 is polarized in the thickness direction.

Using the piezoelectric substrate shown in FIG. 7 as the piezoelectric substrate of the embodiment shown in FIG. 3, extraction electrodes 16a and 16b are formed.
And the capacitor electrode 15b as external electrodes 30a and 30b.
When electrically connected to 30c and 30c respectively, the piezoelectric component having the circuit configuration shown in FIG. 8 is obtained. This piezoelectric component is used, for example, in a filter. In this case, spurious on the high frequency side is reduced.

FIG. 9A is a perspective view showing a modification of the embodiment shown in FIG. 1, and FIG. 9B is a line IXB of FIG. 9A.
FIG. 9C is a schematic cross-sectional view taken along line IXB in FIG.
It is a sectional view solution figure in the line IXC-IXC of (A).
10 is an exploded perspective view of the embodiment shown in FIG.

In the embodiment shown in FIG. 9, compared with the embodiment shown in FIG. 1, in particular, one end of one lead electrode 16a is formed to extend to one end in the width direction of the piezoelectric substrate 12,
The other end of the lead electrode 16b is formed to extend to the other end of the piezoelectric substrate 12 in the width direction. Then, these extraction electrodes 16a and 16b are electrically connected to the external electrodes 28a and 28b by solders 26a and 26b, respectively.

In this embodiment, the vibrating electrodes 14a and 14a
4b is electrically connected to external electrodes 28a and 28b, respectively, so that external electrodes 28a and 28b
Can also be used as an external electrode for input / output. Also, these external electrodes 28a and 28b are solder 26
Extraction electrodes 16a and 16b by a and 26b
, The external electrodes 28a and 28b and the vibrating electrodes 14a and 14b are electrically connected with high reliability.

In the embodiment shown in FIG. 9 as well, as in the embodiment shown in FIG.
Unnecessary vibration is suppressed by the load mass of 6b.

FIG. 11A is a perspective view showing a modification of the embodiment shown in FIG. 3, and FIG. 11B is a sectional view taken along line XIB-XIB in FIG. 11A.
FIG. 11C is a cross sectional view along line XIC-XIC in FIG. FIG. 12 is an exploded perspective view of the embodiment shown in FIG.

In the embodiment shown in FIG. 11, in comparison with the embodiment shown in FIG. 3, in particular, in one main surface of one insulator substrate 18a, a recess 24a is also formed at each of the four sides. Solder 26a, for example, is also embedded as a filling material in these recesses 24a. The external electrodes 30a and 30b are formed on the piezoelectric substrate 12,
It is also formed on one end face and the other end face in the longitudinal direction of the insulating substrates 18a and 18b, respectively. for that reason,
The extraction electrodes 16a and 16b are also electrically connected to the external electrodes 30a and 30b, respectively, by the solder 26a.

Further, also on the one main surface of the other insulating substrate 18b, recesses 24b are formed respectively at the centers of the four sides thereof, and these recesses 24b are each filled with, for example, solder 26b as a filler. Has been.
Therefore, the extraction electrode 16c is electrically connected to the external electrode 30c also by the solder 26b.

In this embodiment, the external electrodes 30a to 30c are used.
Is also connected to the lead electrodes 16a through the solders 26a and 26b.
16c is electrically connected to the external electrodes 30a to 3c.
0c and the vibrating electrodes 14a to 14d are highly reliable in electrical connection.

Further, also in the embodiment shown in FIG. 11, as in the embodiment shown in FIG. 3, unnecessary vibration is suppressed by the load mass of the solders 26a and 26b as the filler.

In the embodiment shown in FIG. 11, the ends of the extraction electrodes 16a and 16b are formed to extend to one end and the other end in the width direction of the one main surface of the piezoelectric substrate 12, respectively. 16a and 16b are
The solder 26a may be electrically connected to the external electrodes 28a and 28b, respectively.

Although solder is used as the filler in each of the above-described embodiments, a metal other than solder or a resin such as a synthetic resin may be used as the filler. Also in this case, unnecessary vibration is suppressed by the mass load of the filler. Furthermore, when a metal is used as the filling material, it is possible to improve the reliability of the electrical connection between the vibrating electrode and the external electrode.

[Brief description of drawings]

FIG. 1A is a perspective view showing an embodiment of the present invention, FIG. 1B is a sectional schematic view taken along line IB-IB in FIG. 1A, and FIG. 1C is a line IC in FIG. -A sectional view of the IC. FIG.

FIG. 2 is an exploded perspective view of the embodiment shown in FIG.

3A is a perspective view showing another embodiment of the present invention, FIG. 3B is a sectional schematic view taken along line IIIB-IIIB in FIG. 3A, and FIG. IIIC-II
It is sectional drawing solution figure in IC.

FIG. 4 is an exploded perspective view of the embodiment shown in FIG.

5 is a bottom view of the piezoelectric substrate used in the embodiment shown in FIG.

FIG. 6 is a circuit diagram of the embodiment shown in FIG.

FIG. 7A is a plan view showing a piezoelectric substrate on which another type of electrode is formed, and FIG. 7B is a bottom view thereof.

FIG. 8 is a circuit diagram of a piezoelectric component using the piezoelectric substrate shown in FIG.

9A is a perspective view showing a modified example of the embodiment shown in FIG. 1, FIG. 9B is a sectional view taken along line IXB-IXB in FIG. 9A, and FIG. Line IXC-IXC
FIG.

FIG. 10 is an exploded perspective view of the embodiment shown in FIG.

11A is a perspective view showing a modification of the embodiment shown in FIG. 3, FIG. 11B is a sectional view taken along line XIB-XIB of FIG. 11A, and FIG. Line XIC-XI
It is a sectional view solution figure in C.

12 is an exploded perspective view of the embodiment shown in FIG.

FIG. 13A is a perspective view showing an example of a conventional piezoelectric component, and FIG. 13B is a sectional schematic view taken along line XIIIB-XIIIB in FIG. 13A.

[Explanation of symbols]

 10 Piezoelectric Components 12 Piezoelectric Substrates 14a, 14b Vibrating Electrodes 16a, 16b Extraction Electrodes 18a, 18b Insulator Substrates 24a, 24b Recesses 26a, 26b Solder 30a, 30b External Electrodes

Claims (2)

[Claims] 1. A piezoelectric substrate having a vibrating electrode on its main surface, and an insulator substrate for sandwiching the piezoelectric substrate, wherein a recess is formed at an end of the insulator substrate, and the insulator is further formed. A piezoelectric component in which a filling material is filled in the recess of the substrate. 2. A lead electrode extending from the vibrating electrode is formed on a main surface of the piezoelectric substrate, an external electrode is formed on a surface of the insulator substrate, the filler is made of metal, and the lead electrode and the The piezoelectric component according to claim 1, wherein an external electrode is electrically connected with the filling material.