JP2002314361A - Piezoelectric resonance parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide piezoelectric resonance parts having a stable oscillation characteristic by narrowing the bandwidth. SOLUTION: A dielectric board 2 has a first terminal electrode 61 and a second terminal electrode 62. The first and second terminal electrodes 61 and 62 confront each other across an interval G1. First and second vibration electrodes 21 and 22 of a piezoelectric resonator 7 face each other on both faces in the thickness direction of a piezoelectric board 1. The piezoelectric resonator 7 is mounted on the surface of the dielectric board 2, and first and second lead electrodes 41 and 42 are connected to the first and second terminal electrodes 61 and 62 respectively, and utilize an equivalent capacitance an that occurs between the first and second terminal electrodes 61 and 62 as equivalent parallel capacitance C3 with respect to the piezoelectric resonator 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric resonance component used for forming an oscillation circuit or the like.

[0002]

2. Description of the Related Art Conventionally, as a resonator for obtaining an oscillation frequency, a piezoelectric resonance component using a ceramic piezoelectric vibrator has been known. The piezoelectric vibrator is on one side and the other side of the piezoelectric substrate,
It has a structure provided with a pair of vibrating electrodes. This piezoelectric vibrator is mounted on a capacitance substrate forming two load capacitances, and is sealed with a cap.

[0003] Such a piezoelectric resonance component is disclosed in, for example, JP-A-60-125120 and JP-A-1-236715.
JP-A-8-237066 or JP-A-8-237066
No. 0-135215.

However, the piezoelectric resonance components described in these prior art documents have a relatively wide bandwidth represented by the width of the resonance frequency and the antiresonance frequency, so that the impedance generated due to various reasons is very small. A change and a slight shift of the oscillation frequency accompanying the change are likely to occur. Therefore, it is difficult to obtain a resonator having high-precision frequency stability.

[0005] When high precision frequency stability is required, it is necessary to reduce the bandwidth as much as possible while satisfying the required Q value. As that means, an auxiliary electrode is provided on the piezoelectric substrate, and the capacitance obtained by the auxiliary electrode is
A method of narrowing the bandwidth by using the equivalent parallel capacitance for the piezoelectric resonator is considered.

However, the auxiliary electrode is limited in size, position, material, etc., which does not affect the vibration characteristics. Therefore, after clearing these restrictions, the equivalent parallel capacitance required for narrowing the bandwidth is reduced. It is not easy to secure.

In addition, the material and thickness of the piezoelectric substrate are selected on the assumption that the piezoelectric substrate satisfies the original piezoelectric characteristics. Therefore, it is not always easy to secure the equivalent parallel capacitance required for narrowing the bandwidth.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a piezoelectric resonance component capable of obtaining stable oscillation characteristics by narrowing a bandwidth.

Another object of the present invention is to provide a piezoelectric resonance component capable of reliably securing an equivalent parallel capacitance necessary for narrowing a band.

[0010]

In order to solve the above-mentioned problems, a piezoelectric resonator according to the present invention includes a dielectric substrate and a piezoelectric resonator. The dielectric substrate has a first terminal electrode and a second terminal electrode on a surface. The first terminal electrode and the second terminal electrode face each other with an interval.

The piezoelectric resonator includes a piezoelectric substrate, a first vibration electrode, a second vibration electrode, a first lead electrode, and a second lead electrode. The first vibrating electrode is provided on one surface in the thickness direction of the piezoelectric substrate. The second
The vibrating electrode is provided on the other surface in the thickness direction of the piezoelectric substrate and faces the first vibrating electrode. The first lead electrode is electrically connected to a first vibration electrode, and the second lead electrode is electrically connected to the second vibration electrode.

The piezoelectric resonator is mounted on the surface of the substrate, and the first and second lead electrodes are connected to the first and second lead electrodes.
And the second terminal electrode.

Then, an equivalent capacitance generated between the first and second terminal electrodes on the front surface side of the dielectric substrate is used as an equivalent parallel capacitance for the piezoelectric resonator.

As described above, the piezoelectric resonance component according to the present invention includes the dielectric substrate, and the first terminal electrode and the second terminal electrode are spaced apart from each other on the surface of the dielectric substrate. Since they are provided facing each other, an equivalent capacitance is generated between the first and second terminal electrodes on the surface side of the dielectric substrate.

The piezoelectric resonator includes a piezoelectric substrate, a first vibrating electrode, and a second vibrating electrode. The first vibrating electrode is provided on one surface in the thickness direction of the piezoelectric substrate. A vibration electrode is provided on the other surface in the thickness direction of the piezoelectric substrate, and faces the first vibration electrode. Therefore, by supplying excitation energy to the first vibration electrode and the second vibration electrode,
A predetermined resonance characteristic can be obtained. The resonance mode to be used is not particularly limited, but it is desirable to use the fundamental wave thickness longitudinal vibration mode from the viewpoint of increasing the Q value.

Further, the piezoelectric resonator includes a first lead electrode and a second lead electrode. The first lead electrode is electrically connected to a first vibration electrode, and the second lead electrode is connected to the second vibration electrode.
Are electrically connected to the second vibrating electrode. Therefore, from a position that does not affect the vibration characteristics,
Excitation energy can be supplied to the first and second vibrating electrodes via the first and second lead electrodes.

Here, in the present invention, since a capacitance is generated between the first and second terminal electrodes on the surface side of the dielectric substrate, the piezoelectric resonator is mounted on the surface of the dielectric substrate,
When the first and second lead electrodes are connected to the first and second terminal electrodes, respectively, the resonance frequency and the anti-resonance are utilized by utilizing the equivalent parallel capacitance generated between the first and second terminal electrodes. The bandwidth between frequencies can be narrowed, and the oscillation frequency can be stabilized as compared with the related art.

In addition, since the equivalent parallel capacitance is obtained by using a dielectric substrate different from the piezoelectric resonator, a conventional technique for obtaining an equivalent parallel capacitance by providing an auxiliary electrode on the piezoelectric substrate constituting the piezoelectric resonator is known. Unlike the above, the restriction on the first and second terminal electrodes for obtaining the equivalent parallel capacitance is remarkably relaxed. For this reason, the equivalent parallel capacitance required for band narrowing can be reliably set to a required value.

The dielectric substrate can be made of a material suitable for obtaining an equivalent parallel capacitance independently of the piezoelectric characteristics without being affected by the piezoelectric characteristics. Can be obtained simply and reliably.

Other objects, configurations and advantages of the present invention will be described in more detail with reference to the accompanying drawings. The illustration is merely an example.

[0021]

FIG. 1 is an exploded perspective view of a piezoelectric resonance component according to the present invention, FIG. 2 is a perspective view showing an assembled state of the piezoelectric resonance component shown in FIG. 1, and FIG. 3 is FIGS. 3 is a front sectional view of the piezoelectric resonance component shown in FIG. The illustrated piezoelectric resonance component includes a dielectric substrate 2 and a piezoelectric resonator 7.

The dielectric substrate 2 has a first terminal electrode 6 on its surface.
It has first and second terminal electrodes 62. First terminal electrode 6
The first and second terminal electrodes 62 face each other with an interval G1. In the illustrated embodiment, the first terminal electrode 61 and the second terminal electrode 62 have opposite edge portions 610, 620.
And the distance G1 is controlled by the amount of protrusion. By controlling the interval G1 described above,
On the front surface side of the dielectric substrate 2, opposing edge portions 61
The value of the equivalent capacitance C3 generated between 0 and 620 is controlled. The equivalent capacitance C3 is actually equal to the edge 610,
620, which is equivalently represented as a lumped constant. As the dielectric substrate 2,
Ba (Ti, Zr) O ₃ ceramic dielectric material can be used.

The dielectric substrate 2 of the illustrated embodiment has
It has a first capacitance electrode 63, a third capacitance electrode 65, and a second capacitance electrode 64. The first capacitor electrode 63 is
The third capacitor electrode 65 is electrically connected to the second terminal electrode 62 via the second side electrode 67 via the second side electrode 67. It is conducting.

The second capacitance electrode 64 is connected to the first capacitance electrode 6
The third capacitor electrode 65 is disposed between the third capacitor electrode 65 and the third capacitor electrode 65, and opposes to each other at intervals G2 and G3 (see FIG. 3).

The piezoelectric resonator 7 includes the piezoelectric substrate 1, a first vibration electrode 21, a second vibration electrode 22, a first lead electrode 41, and a second lead electrode 42. Piezoelectric substrate 1
Has a width of 1.2 mm, a length of 1.2 mm, and a thickness of 0.5 mm as an example.

The piezoelectric substrate 1 is obtained by polishing a sintered body to a predetermined thickness, and subjecting the sintered body to a polarization treatment in a thickness direction under a high electric field.
As a material of the piezoelectric substrate 1, a lead-free material containing no PbO is used in consideration of the environment. The piezoelectric substrate 1 can be made of a piezoelectric material having an effective Poisson's ratio of less than 1/3. Even if a material having an effective Poisson ratio of less than 1/3 is used, a good waveform can be obtained for the fundamental wave.

Examples of the piezoelectric material having an effective Poisson's ratio of less than 1/3 include compounds having a perovskite structure such as a tantalate compound or a niobate compound and solid solutions thereof, compounds having an ilmenite structure and solid solutions, and compounds having a pyrochlore structure. , A compound having a layered structure containing bismuth, or a compound having a tungsten bronze structure. The piezoelectric substrate 1 contains these piezoelectric materials as the main components, which are the largest components.

Examples of the tantalum compound or the niobate compound include, for example, at least one first element selected from the group consisting of sodium (Na), potassium (K), and lithium (Li); ) And niobium (Nb) and at least one second element from the group consisting of oxygen and oxygen. Assuming that the first element is A and the second element is B,
It is represented by the general formula ABO ₃ . Examples of the layer structure compound containing bismuth include, for example, bismuth, sodium, potassium, barium (Ba), and strontium (S
r), lead (Pb), calcium (Ca), yttrium (Y), and at least one first element from the group consisting of lanthanoids (Ln), bismuth, and the like;
At least one second element selected from the group consisting of vanadium (V), zirconium (Zr), antimony (Sb), titanium (Ti), niobium, tantalum, tungsten (W), molybdenum (Mo), and the like; And those containing oxygen. Assuming that the first element is C and the second element is D, the following general formula (Bi ₂ O ₂ ) ²⁺ (C _m-1 D _m O _{3m + 1} ) ^2- It is represented by an integer from 1 to 8. Further, the dangling stainless bronze compounds Formula not include, for example, NaW0 ₆ BaNaNbO _15. However, all of the chemical formulas shown here are expressed in stoichiometric compositions, and the piezoelectric material constituting the piezoelectric substrate 1 may be non-stoichiometric.

Incidentally, among these, a layered structure compound containing bismuth is preferable as the piezoelectric material constituting the piezoelectric substrate 1. Mechanical quality factor Q _m and Curie temperature is large, because in particular it is possible to obtain excellent characteristics as a resonator. For example, a layered compound containing bismuth, strontium, titanium and oxygen is preferable, and a layered compound containing lanthanum is more preferable.

The first vibration electrode 21 is provided on one surface 101 in the thickness direction of the piezoelectric substrate 1. Second vibrating electrode 2
2 is provided on the other surface 102 of the piezoelectric substrate 1 in the thickness direction,
It faces the first vibration electrode 21. The first vibrating electrode 21 and the second vibrating electrode 22 can adopt a circular shape in addition to the rectangular shape shown in the figure. These first and second vibrating electrodes 21 and 22 can be formed by, for example, a thin film technique such as a vacuum evaporation method or a sputtering method or a thick film printing technique. The material is Au, Ag, C
u, Cr, or an alloy thereof can be used.

The first lead electrode 41 is electrically connected to the first vibration electrode 21 and the second lead electrode 42
Are electrically connected to the second vibration electrode 22. First
Also, the second lead electrodes 41 and 42 can also be formed by a thin film technique such as a vacuum evaporation method or a sputtering method or a thick film printing technique. The material is Au, Ag, C
u, Cr, or an alloy thereof can be used.

The piezoelectric resonator 7 is mounted on the surface of the dielectric substrate 2, and the first and second lead electrodes 41, 42 are connected to each other by solder, metal bonding material, alloy bonding material or other bonding material 5. They are connected to the first and second terminal electrodes 61 and 62, respectively. The periphery of the piezoelectric resonator 7 mounted on the dielectric substrate 2 is sealed by a case 8 (see FIG. 3).
FIG. 4 is an equivalent circuit diagram of the piezoelectric resonance component shown in FIGS. The piezoelectric resonance component includes a first terminal electrode with respect to an equivalent circuit of the piezoelectric resonator 7 in which an equivalent capacitance C2 is connected in parallel to a series circuit of an equivalent resistance R, an equivalent inductance L, and an equivalent capacitance C1 included in the piezoelectric resonator 7. An equivalent parallel capacitance C3 between 61 and 62 is formed. Further, a circuit configuration is obtained in which the capacitor C4 is connected between the terminal electrodes 63 and 64, and the capacitor C5 is connected between the terminal electrodes 64-65.

The piezoelectric resonator 7 shown in FIGS.
Since the first terminal electrode 61 and the second terminal electrode 62 are mounted on the dielectric substrate 2 and provided on the surface of the dielectric substrate 2 so as to face each other with an interval G1 therebetween, On the front side of the substrate 2, the first and second terminal electrodes 61,
62, an equivalent parallel capacitance C3 (see FIG. 4) is generated.

The piezoelectric resonator 7 includes the piezoelectric substrate 1, a first vibrating electrode 21, and a second vibrating electrode 22. The first vibrating electrode 21 is disposed on one surface of the piezoelectric substrate 1 in the thickness direction. The second vibration electrode 22 is provided on the other surface in the thickness direction of the piezoelectric substrate 1, and faces the first vibration electrode 21.
Therefore, by supplying excitation energy to the first vibrating electrode 21 and the second vibrating electrode 22, predetermined resonance characteristics can be obtained. The resonance mode to be used is not particularly limited, but it is desirable to use the fundamental wave thickness longitudinal vibration mode from the viewpoint of increasing the Q value.

Further, the piezoelectric resonator 7 includes a first lead electrode 41 and a second lead electrode 42. The first lead electrode 41 is electrically connected to the first vibration electrode 21, and the second lead electrode 42 is electrically connected to the second vibration electrode 22. Therefore, excitation energy can be supplied to the first and second vibration electrodes 21 and 22 from the position that does not affect the vibration characteristics via the first and second lead electrodes 41 and 42.

The piezoelectric resonator 7 is mounted on the surface of the dielectric substrate 2, and the first and second lead electrodes 41 and 42 are connected to the first and second lead electrodes 41 and 42, respectively.
And the second terminal electrodes 61 and 62, respectively.
The first and second terminal electrodes 61 and 62 are connected to the first and third capacitance electrodes 63 and 65 provided on the back surface of the dielectric substrate 2, and are connected between the first and third capacitance electrodes 63 and 65. In
A second capacitance electrode 64 is provided. Therefore, the piezoelectric resonance component can be mounted on a circuit board or the like using the first to third capacitance electrodes 63 to 65.

Since an equivalent parallel capacitance C3 is generated between the first and second terminal electrodes 61 and 62 on the surface of the dielectric substrate 2, the piezoelectric resonator 7 is mounted on the surface of the dielectric substrate 2, When the first and second lead electrodes 41 and 42 are connected to the first and second terminal electrodes 61 and 62, respectively,
By controlling the equivalent parallel capacitance C3 generated between the first and second terminal electrodes 61 and 62, the bandwidth between the resonance frequency and the anti-resonance frequency can be narrowed, and the oscillation frequency can be stabilized.

Further, since the equivalent parallel capacitance C3 is obtained by using the dielectric substrate 2 different from the piezoelectric resonator 7,
Unlike the related art in which an auxiliary electrode is provided on the piezoelectric substrate 1 constituting the piezoelectric resonator 7 to obtain the equivalent parallel capacitance C3, the first and second terminal electrodes 61 for obtaining the equivalent parallel capacitance C3,
The restriction on 62 is significantly relaxed. For this reason, the equivalent parallel capacitance C3 required for narrowing the band can be reliably set to a required value.

The dielectric substrate 2 can be made of a material suitable for obtaining the equivalent parallel capacitance C3 independently of the piezoelectric characteristics without being affected by the piezoelectric characteristics. The capacitance C3 can be obtained simply and reliably.

FIG. 5 is an exploded perspective view showing another embodiment of the piezoelectric resonance component according to the present invention, FIG. 6 is a perspective view showing an assembled state of the piezoelectric resonance component shown in FIG. 5, and FIGS. FIG. 8 is a perspective view of the piezoelectric resonator included in the piezoelectric resonance component shown in FIG. In the figure, the same components as those shown in FIGS. 1 to 3 are denoted by the same reference numerals, and redundant description will be omitted.

The illustrated piezoelectric resonator 7 shows an example suitable for operating in the thickness longitudinal vibration mode. More specifically, a fundamental vibration mode is used. The first lead electrode 41 has a first pad 51, and the second lead electrode 42 has a second pad 52.

Each of the first and second pads 51 and 52 is provided at a corner of the other surface 102 in the thickness direction of the piezoelectric substrate 1. The first and second pads 51 and 52 are
In the corner portion, particularly, a region having a small amount of vibration displacement is selected and formed in the region. Although the illustrated first and second pads 51 and 52 are circular, other shapes,
For example, it may be square.

The first pad 51 is made of a conductor, and is electrically connected to the first vibrating electrode 21. In the illustrated embodiment, since the first pad 51 is formed on the other surface 102 opposite to the one surface 101 on which the first vibration electrode 21 is formed, the lead electrode 41 passing through the other surface 102 and the one surface 101 is formed. Is electrically connected to the first vibrating electrode 21 via the. The lead electrode 41 is basically composed of the first vibrating electrode 2
1 is made of the same conductive material.

The illustrated first pad 51 includes a conductor film 511 and a bump 512 as shown in an enlarged manner in FIG. The conductor film 511 is formed on the other surface 102 of the piezoelectric substrate 1.
Directly attached. The bump 512 is made of the conductive film 5.
11 so as to protrude above 11. Bump 5
12 may include at least one selected from Au, Pt, Pd, Ag, Cu, Ni, Al or an alloy thereof, or solder. The same applies to the conductor film 511.

The second pad 52 is made of a conductor, and is electrically connected to the second vibrating electrode 22. In the case of the illustrated embodiment,
The second pad 52 is formed on the other surface 102 on which the second vibration electrode 22 is formed, and is electrically connected to the second vibration electrode 22 by the lead electrode 42 formed on the other surface 102. You. The lead electrode 42 is basically formed of the same conductive material as the second vibration electrode 22.

The second pad 52 also includes a conductor film 521 and a bump 522, like the first pad 51 described with reference to FIG. The conductor film 521 is formed on the piezoelectric substrate 1
Is directly attached to the other surface 102. Bump 522
Is attached on the conductor film 521 so as to protrude (see FIG. 8). The thickness of the second pad 52 matches the thickness of the first pad 51.

In the embodiment shown in FIGS.
It includes a third pad 53 and a fourth pad 54. Each of the third pad 53 and the fourth pad 54 is provided at a corner portion of the other surface 102 of the piezoelectric substrate 1. The third and fourth pads 53 and 54 are formed in a corner portion, particularly, in a region having a small vibration displacement amount. The thicknesses of the third and fourth pads 53 and 54 match the thicknesses of the first and second pads 51 and 52. The illustrated third and fourth pads 53,5
4 is a circular shape, but may be another shape, for example, a polygonal shape.

The illustrated third pad 53 includes a conductive film 531 and a bump 532 as shown in an enlarged manner in FIG. The conductor film 531 is formed on the other surface 102 of the piezoelectric substrate 1.
Directly attached. The bump 532 is made of the conductive film 5
It is attached so as to protrude above 31.

The fourth pad 54 also includes a conductor film 541 and a bump 542, like the first pad 51 described with reference to FIG. The conductor film 541 is formed of the piezoelectric substrate 1
Is directly attached to the other surface 102. Bump 542
Is attached on the conductor film 541 so as to protrude.

In the second pad 52 to the fourth pad 54, the conductor films 521, 531, 541 and the bump 52
2, 532, 542 are Au, Pt, Pd, Ag, C
At least one selected from u, Ni, Al or an alloy thereof, or solder may be included.

In the piezoelectric resonator 7 shown in FIGS. 5 to 8, the first vibrating electrode 21 is provided on one surface in the thickness direction of the piezoelectric substrate 1, and on the other surface in the thickness direction of the piezoelectric substrate 1, A second vibration electrode 22 is provided. This second vibrating electrode 2
2 faces the first vibrating electrode 21. Therefore,
By supplying electric energy to the first vibration electrode 21 and the second vibration electrode 22, the piezoelectric resonator 7 is
It can be operated in the thickness longitudinal vibration mode.

Of the first terminal electrode 61 and the second terminal electrode 62 provided on the dielectric substrate 2, the first terminal electrode 6
1 has protrusions 611 and 612 in a portion receiving the first pad 51 and the third pad 53, and has a second terminal electrode 6.
2 has protrusions 621 and 622 at portions where the second pad 52 and the fourth pad 54 are received. First and second
Between the terminal electrode 61 and the second terminal electrode 62, an equivalent parallel capacitance C3 mainly determined by the gaps G11 and G12 between the protrusions 611 and 612 and the protrusions 621 and 622, the facing length, and the like. Occurs.

The piezoelectric resonator 7 includes first and second pads 5
The first pad 51 is made of a conductor and is electrically connected to the first vibrating electrode 21. The second pad 52 is made of a conductor and is connected to the second vibrating electrode 22. It becomes electrically conductive. Therefore, electric energy can be supplied to the first and second pads 51 and 52 to excite the piezoelectric resonator 7.

When the hexahedral piezoelectric substrate 1 is operated in the thickness longitudinal vibration mode, a region where vibration displacement is minimized is formed at each of the four corners on both sides in the thickness direction. In the embodiment, each of the first and second pads 51 and 52 is provided at a corner portion of the other surface 102 of the piezoelectric substrate 1. Therefore, the first and second pads 51 and 52 are provided at positions where the vibration displacement is small. Therefore, the first and second pads 51, 52
Therefore, the piezoelectric resonator 7 can be stably supported by minimizing the attenuation of the vibration energy due to the vibration.

In the case of the embodiment, the third and fourth pads 5
3 and 54 are also provided at the corners of the other surface 102 of the piezoelectric substrate 1. For this reason, the first to fourth bads 51 to 54
Is formed, the attenuation of the vibration energy by the third and fourth pads 53 and 54 is minimized, and the piezoelectric resonator 7 can be stably supported. One of the third and fourth pads 53 and 54 may be omitted to provide a three-point support structure.

By the above-described operation, oscillation defects such as dissipation of vibration energy, insufficient suppression of unnecessary vibration, deterioration of resonance characteristics, and unstable oscillation jump are suppressed, and the Qmax value, which is a representative value of resonance characteristics, is large. The piezoelectric resonator 7 that can exhibit stable resonance characteristics is realized.

In the embodiment, the first pad 51, the second pad 52, the third pad 53, and the fourth pad 5
4 includes conductor films 511, 521, 531, 541 and bumps 512, 522, 532, 542. Conductive film 5
11, 521, 531 and 541 are attached to the surface of the piezoelectric substrate 1, and the bumps 512, 522, 532 and 542 are attached on the conductor films 511, 521, 531 and 541.

In the case where the piezoelectric resonator 7 is mounted on the dielectric substrate 2 or the like, conventionally, a conductive paste or the like has been used to directly bond the piezoelectric resonator. However, in the case of the piezoelectric resonator 7 using the fundamental wave vibration mode, in the mounting connection of the piezoelectric substrate 1 on the dielectric substrate, a variation in the adhesive area due to a change in viscosity at the time of connection of the conductive paste and bleeding, etc. The connection strength becomes unstable, and characteristic deterioration due to suppression of vibration energy of the piezoelectric resonator 7 and deterioration of resonance characteristics due to insufficient suppression of unnecessary vibration may occur, and oscillation failure such as unstable oscillation jump may occur. In forming the first pad 51 and the second pad 52, conductive films 511, 521, 531, and 541 are attached to the surface of the piezoelectric substrate 1.
Bumps 512 and 5 on 11, 521, 531 and 541
22, 532, and 542 are provided, and the above-mentioned problems can be solved by means such as conductive paste, solder paste, or ultrasonic bonding via these bumps.

When adhered, the problem caused by such a conductive paste can be solved.

FIG. 9 is a perspective view showing another embodiment of the piezoelectric resonance component according to the present invention. In the drawings, the same components as those shown in FIGS. 1 to 8 are denoted by the same reference numerals. In this embodiment, the third and fourth pads 53 and 54 are made of an insulator. This embodiment shows that the third and fourth pads 53 and 54 do not necessarily have to have the same conductor structure as the first and second pads 51 and 52.

On the other surface 102 of the piezoelectric substrate 1, a second pad 52, a third pad 53, a fourth pad 54 and a fifth pad
Pad 55 is provided. That is, the first pad 5
The first and second pads 52 can be arranged on different surfaces.

The first substrate 101 formed on one surface 101 of the piezoelectric substrate 1
The pad 51 is connected to the terminal electrode 62 by means such as a wire bonder 46, for example.

The steps for manufacturing the piezoelectric substrate 1 are already well known. For example, mainly oxide materials are used as starting materials, they are weighed to have a desired composition, and ball mill mixing is performed using zirconia balls in a solvent such as pure water or acetone. Next, after the mixed raw material powder is sufficiently dried, it is calcined at a temperature of 700 to 900 ° C. by, for example, press molding.

Subsequently, for example, the calcined body is again ball-milled, dried, and granulated by adding an appropriate amount of polyvinyl alcohol as a binder.

After granulation, the granulated powder is formed into a thin plate having a length of 20 mm, a width of 20 mm and a thickness of about 1.5 mm by using a uniaxial press molding machine under a load of 200 to 300 MPa.

Next, the binder is volatilized from the molded body by, for example, heat treatment, and the main firing is performed at a temperature of 1100 to 1350 ° C. After the main firing, the thickness of the fired body is adjusted by polishing using, for example, a lap polishing machine, and then, mirror-finished to form a base material plate of the piezoelectric substrate 1.

After forming the base material plate, for example, copper (Cu)
Is formed by vacuum evaporation to form polarization processing electrodes on both surfaces of the base material plate. Thereafter, for example, the base material plate on which the electrodes for polarization processing are formed is immersed in silicon oil heated to 200 to 300 ° C., and an electric field of 5 to 10 Kv / mm is applied for 1 minute to perform polarization processing.

After the polarization processing, the polarization processing electrodes are removed, the size of the base material plate is adjusted by dicing or the like, and the piezoelectric substrate 1 is formed. Next, an electrode made of a metal such as silver is formed on the opposing surface of the piezoelectric substrate 1 by, for example, sputtering. Thereby, the piezoelectric resonator 7 is formed.

[0069]

As described above, according to the present invention, the following effects can be obtained. (A) By narrowing the bandwidth, it is possible to provide a piezoelectric resonance component capable of obtaining stable oscillation characteristics. (B) It is possible to provide a piezoelectric resonance component capable of reliably securing an equivalent parallel capacitance necessary for narrowing the band.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a piezoelectric resonance component according to the present invention.

FIG. 2 is a perspective view showing an assembled state of the piezoelectric resonance component shown in FIG. 1;

FIG. 3 is a front sectional view of the piezoelectric resonance component shown in FIGS. 1 and 2;

FIG. 4 is an equivalent circuit diagram of the piezoelectric resonance component shown in FIGS. 1 to 3;

FIG. 5 is an exploded perspective view showing another embodiment of the piezoelectric resonance component according to the present invention.

FIG. 6 is a perspective view showing an assembled state of the piezoelectric resonance component shown in FIG. 5;

FIG. 7 is a perspective view of a piezoelectric resonator included in the piezoelectric resonance component shown in FIGS. 5 and 6, as viewed from a bottom surface side.

FIG. 8 is an enlarged view of a pad portion of FIG. 7;

FIG. 9 is a perspective view showing another embodiment of the piezoelectric resonance component according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric substrate 21, 22 First and second vibrating electrodes

Claims (9)

[Claims] 1. A piezoelectric resonance component including a dielectric substrate and a piezoelectric resonator, wherein the dielectric substrate has a first terminal electrode and a second terminal electrode on a surface thereof, and The terminal electrode and the second terminal electrode face each other at an interval, and the piezoelectric resonator includes a piezoelectric substrate, a first vibration electrode, a second vibration electrode, a first lead electrode, A second lead electrode, wherein the first vibration electrode is provided on one surface in the thickness direction of the piezoelectric substrate, and the second vibration electrode is provided on the other surface in the thickness direction of the piezoelectric substrate. The first lead electrode is electrically connected to the first vibrating electrode, and the second lead electrode is connected to the second vibrating electrode. Electrically conductive, the piezoelectric resonator is mounted on the surface of the substrate, 2 lead electrodes are respectively connected to the first and second terminal electrodes, and the equivalent capacitance generated between the first and second terminal electrodes on the front side of the dielectric substrate is A piezoelectric resonance component used as an equivalent parallel capacitance for a piezoelectric resonator. 2. The piezoelectric resonance component according to claim 1, wherein the distance between the first and second terminal electrodes is substantially constant. 3. The piezoelectric resonance component according to claim 1, wherein the distance between the first and second terminal electrodes is:
A piezoelectric resonance component that changes in its opposing length. 4. The piezoelectric resonance component according to claim 1, wherein the dielectric substrate has a first surface on a back surface side.
A first capacitance electrode, a second capacitance electrode, and a third capacitance electrode, wherein the first capacitance electrode is electrically connected to the first terminal electrode; Is electrically connected to the second terminal electrode, and the second capacitor electrode is connected to the first capacitor electrode and the third terminal electrode.
The piezoelectric resonance component is disposed between the capacitor and the capacitor electrode, and is opposed to both at a distance. 5. The piezoelectric resonance component according to claim 1, wherein the first lead electrode includes a first pad, and the first lead electrode includes a first pad at a portion of the first pad. And a second lead electrode including a second pad, and a portion of the second pad connected to the second terminal electrode. 6. The piezoelectric resonance component according to claim 5, wherein each of the first and second pads is at least one surface in a thickness direction of the piezoelectric substrate and has a small vibration displacement. Piezoelectric resonance component provided in. 7. The piezoelectric resonance component according to claim 5, wherein the portion having the small vibration displacement is a portion selected at least in four corner portions on the one surface. 8. The piezoelectric resonance component according to claim 1, wherein the piezoelectric resonance component uses a fundamental wave thickness longitudinal vibration mode. 9. The piezoelectric resonance component according to claim 1, wherein the piezoelectric substrate is made of a lead-free piezoelectric material.