JP2003171175A - Piezoelectric ceramic composition, and piezoelectric element using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a piezoelectric ceramic composition for producing a piezoelectric element having piezoelectric properties such as the temperatuer properties and oscillation properties of resonance frequency. <P>SOLUTION: A second glass material other than a first glass material forming a Pb-W based glass phase is added to a piezoelectric ceramic composition composing piezoelectric ceramic 1, and is expressed by the general formula of Pb<SB>x</SB>M<SB>y</SB>TiO<SB>3</SB>+αMnO<SB>2</SB>+βWO<SB>3</SB>+γN<SB>u</SB>O<SB>v</SB>(M is La or La/Nd, and N<SB>u</SB>O<SB>v</SB>is the oxide composition of the above second glass material). The addition weight γof the second glass material satisfies 0.015≤γ≤0.040. As for the contained molar quantities of the Pb component and M component, (x) and (y) respectively satisfy 0.790≤x≤0.910 and 0.060≤y≤0.135 (wherein, x=1-(1.5 y+z), and 0.000≤z≤0.070). As for the addition molar quantities of MnO<SB>2</SB>and WO<SB>3</SB>, αand β respectively satisfy 0.010≤α≤0.032, and 0.007≤β≤0.020 (wherein, 0.50≤α/β≤4.00). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a piezoelectric ceramic composition,
The present invention also relates to a piezoelectric element, and more particularly to a piezoelectric ceramic composition used for a piezoelectric element such as a piezoelectric oscillator, and a piezoelectric element such as a piezoelectric oscillator manufactured using the piezoelectric ceramic composition.

[0002]

2. Description of the Related Art Pb (Ti, Zr) O ₃ (lead zirconate titanate) has been conventionally used for piezoelectric elements such as piezoelectric oscillators.
And PbTiO 3 piezoelectric ceramic mainly composed of _(lead titanate) have been widely used.

Nowadays, there is a demand for higher performance of the piezoelectric element, and therefore the manufacturing cost is lowered and the efficiency of conversion of electric energy applied between the electrodes of the piezoelectric body into mechanical energy is improved. It has been required to keep the electromechanical coupling coefficient K shown high.

Therefore, from such a viewpoint, 2PbO.WO ₃ as a glass material is added to the porcelain composition in an amount of 1 wt% to 10%.
A technique in which wt% is added has been proposed (JP-A-1-14).
No. 8744; hereinafter referred to as "first conventional technique".

In the first prior art, 2PbO.WO ₃
Since the glass component has a low-temperature sintering effect and an effect of suppressing a decrease in the electromechanical coupling coefficient K, for example, (Pb
_0.85 La _0.1 ) TiO ₃ +0.5 wt% MnO ₂
1% by weight to 10% by weight of glass powder of 2PbO.WO ₃ is added to the porcelain composition shown in Fig. 1 to suppress sintering of the electromechanical coupling coefficient K at a low temperature of 1050 ° C or lower. I have to.

Further, a high Curie point at which a ferroelectric substance is transformed into a paraelectric phase is required in order to enable use in a high temperature environment, and a dielectric constant is required in order to be suitable for use in a high frequency region. Therefore, a technique has been proposed in which lead titanate is the main component, a manganese compound and a tungsten compound are contained as auxiliary components, and a silicon compound is added (Japanese Patent Laid-Open No. 2001-80956). Gazette; hereinafter referred to as "second conventional technology").

In the second conventional technique, PbTiO ₃ (lead titanate), which has the advantage of having a high Curie point and a low dielectric constant, is used as a main component, and the general formula (Pb _(1-1.5x) M
_x ) TiO ₃ + Pb (Mn _y W _(1-y) ) O ₃ + Si
O ₂ (M is at least one of La, Nd, and Ce)
By using the magnetic composition represented by the above as a ceramic body, a piezoelectric oscillator suitable for use in a high frequency region under a high temperature environment is obtained.

Moreover, in the second prior art, since the silicon compound is added to the magnetic composition, it is possible to prevent the glass phase of Pb-W system from segregating in the sintered body. As a result, it is possible to prevent variations in electrical characteristics between the piezoelectric elements and reduction in mechanical strength.

[0009]

However, in the first prior art, the manufacturing cost is reduced and the electromechanical coupling is achieved by adding 1 wt% to 10 wt% of a glass material made of 2PbO.WO ₃ to the porcelain composition. Although the reduction of the coefficient K is suppressed, the Pb-W-based glass phase (aggregate) formed in the firing step segregates and intervenes in the crystal body. There are problems that the characteristics are varied and the mechanical strength is lowered.

In the second prior art, the segregation of the Pb-W glass phase can be prevented by adding the silicon compound to the porcelain composition, but on the contrary, the segregation does not occur, so that the crystal grains are not formed. There is a problem that the pores in the boundary remain without being filled, and as a result, the compactness of the sintered body deteriorates and the resonance frequency changes with temperature.

The present invention has been made in view of the above problems, and a piezoelectric ceramic composition capable of manufacturing a piezoelectric element having excellent piezoelectric characteristics such as temperature characteristics and oscillation characteristics of resonance frequency, and It is an object to provide a piezoelectric element using the same.

[0012]

It is considered that the cause of the decrease in the temperature characteristic and the oscillation characteristic of the resonance frequency in the piezoelectric element such as the piezoelectric oscillator is that the magnetic composition, which is the ceramic body, has low density. To obtain a dense magnetic composition, P
It is considered effective to segregate the glass phase of the bW type glassy material as a main component in the crystal to some extent, thereby filling the pores remaining in the crystal grain boundaries.

Therefore, the inventors of the present invention have made earnest studies from such a viewpoint, and found that the second glass material is added to the porcelain composition in addition to the first glass material forming the Pb-W glass phase. As a result, it was found that the segregation state of the glass phase in the crystal can be controlled. And the second
By adding 0.015% to 0.040% by weight of the glass material, the glass phase containing the Pb-W glass component as a main component can be uniformly dispersed in the crystal and segregated. This has led to the finding that a dense porcelain composition can be obtained without causing variations in electrical characteristics.

The present invention has been made on the basis of such findings, and the piezoelectric ceramic composition according to the present invention contains lead-
In a piezoelectric ceramic composition in which a first glass material forming a tungsten glass phase is added to a piezoelectric ceramic material, a second glass material other than the first glass material is
It is characterized by adding 0.015% to 0.040% by weight.

That is, according to the above construction, the second glass material is contained in an amount of 0.015% to 0.040 in addition to the first glass material.
%, It is possible to segregate the glass phase having a Pb-W-based glass component as a main component in a state where the glass phase is uniformly dispersed in the crystal body, thereby filling the pores of the crystal grain boundaries. As a result, it is possible to obtain a densified piezoelectric ceramic composition without causing variations in electrical characteristics.

As the piezoelectric ceramic material,
Pb (Ti, Zr) O ₃ and PbTiO ₃ as well as BaTi
Although there are various kinds of O _{3 and the} like, among them, the ceramic material containing PbTiO ₃ as a main component has a high Curie point and can suppress the dielectric constant to a low level, so that a piezoelectric element suitable for use in a high temperature environment or a high frequency region It is possible to obtain
Then, as a result of earnest studies by the present inventors, a part of the Pb component contained in PbTiO ₃ was changed to La (lanthanum) or L
It has been found that the oscillation characteristics of the piezoelectric element can be improved by substituting a and Nd (neodymium).

Therefore, the piezoelectric ceramic composition of the present invention is characterized in that the piezoelectric ceramic material contains PbTiO ₃ as a main component and a part of the Pb component is replaced with La, or La and Nd. There is.

Further, in order to adapt the piezoelectric element for use in a high frequency range, it is necessary to polish the piezoelectric element to reduce its thickness, and therefore, cracks or cracks do not occur during the polishing process. It is necessary to secure good mechanical strength. Therefore, the second glass material needs to have good mechanical strength in addition to the function of controlling the segregation state. From this viewpoint, it is preferable that the second glass material contains a silicon compound. preferable.

Therefore, the piezoelectric magnetic composition of the present invention is characterized in that the second glass material contains a silicon compound.

Further, the piezoelectric magnetic composition of the present invention is characterized in that particles having a particle size of 2 μm to 40 μm are segregated and interposed in the crystal body.

That is, by segregating and interposing particles having a particle size of 2 μm to 40 μm in the crystal, the segregated particles having a large particle size are uniformly dispersed without being locally present, whereby the segregated particles are dispersed. It is possible to obtain a densified magnetic composition without causing variations in electrical characteristics or reducing mechanical strength.

Further, the piezoelectric ceramic composition of the present invention have the general formula _{Pb x M y TiO 3 + αMnO} 2 + βWO 3 + γN u O
_v (M is La, or La / Nd, N _u O _v shows the oxide composition of the second glass material) is represented by the addition weight of the second glass material γ, by weight%, 0.015 ≦ γ ≦
While being set to 0.040, the molar content x of Pb component and the molar content y of M are 0.790 ≦ x ≦ 0.9, respectively.
10, 0.060 ≦ y ≦ 0.135 (where x = 1−
(1.5y + z) and 0.000 ≦ z ≦ 0.0
70), and the addition molar amount α of MnO ₂ and the addition molar amount β of WO ₃ are each 0.010 ≦ α.
≦ 0.032, 0.007 ≦ β ≦ 0.020 (however,
It is characterized in that it is set to 0.500 ≤ α / β ≤ 4.000).

Considering the prevention of evaporation of the Pb component during firing and the reduction of product cost, it is desirable to keep the firing temperature as low as possible. From this viewpoint, it is preferable to add W oxide. Then, as a result of further intensive research conducted by the present inventors in order to obtain desired piezoelectric characteristics, the molar amount x of Pb component, the molar amount y of M component, the molar amount α of MnO ₂ added,
And the optimum range of the addition molar amount β of WO ₃ was found. That is, it is possible to obtain a piezoelectric ceramic composition having excellent frequency-temperature characteristics, oscillation characteristics and other piezoelectric characteristics by setting the above-described molar amounts x and y and the molar amounts added α and β in the ranges described above. Becomes

In the above general formula, as the M component (La /
When Nd) is used, it is preferable to set La / Nd ≧ 1.0 because it is necessary to avoid deterioration of frequency temperature characteristics and oscillation characteristics.

Therefore, the piezoelectric magnetic composition of the present invention is characterized in that the molar ratio La / Nd of the La component to the Nd component in the above general formula is set to La / Nd ≧ 1.0.

Further, the piezoelectric element according to the present invention is characterized in that a ceramic body is formed of the above-mentioned piezoelectric ceramic composition.

According to the above structure, since the piezoelectric ceramic composition is formed by uniformly dispersing segregated particles having an appropriate particle size, a piezoelectric element having excellent mechanical strength and various piezoelectric characteristics can be obtained. be able to.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a piezoelectric ceramic composition for a piezoelectric oscillator will be described as an embodiment of the present invention.

The piezoelectric ceramic composition according to the present embodiment is
It is represented by the general formula (1).

[0030] _{Pb x La y TiO 3 + αMnO} 2 + βWO 3 + γN u O v ... (1) where, N _u O _v a second glass material other than the first glass material for forming a Pb-W-based glass phase 3 shows the composition of the oxide forming the.

The composition of the piezoelectric ceramic composition will be described below.

As the piezoelectric ceramic material, there are various kinds such as Pb (Ti, Zr) O ₃ , PbTiO ₃ and BaTiO ₃ as mentioned above, but in order to maintain stable and good piezoelectricity even at high temperature, , It is desirable that the critical point at which the piezoelectricity disappears due to the transition from the ferroelectric phase to the paraelectric phase, that is, the Curie point is as high as possible, and 10 MHz to 80 M
A low dielectric constant is required in order to be suitable for use in the high frequency region of Hz. Therefore, in this embodiment, PbTiO ₃ is used as the main component of the piezoelectric ceramic material.

Further, in this type of piezoelectric oscillator, the third harmonic of the thickness longitudinal vibration mode of the piezoelectric ceramic composition is widely used, and in order to obtain good oscillation characteristics, the third harmonic phase angle θ It is required to be expensive. Therefore, in the present embodiment, PbT
A part of the Pb component in iO ₃ is replaced with the La component.

Further, in order to reduce the manufacturing cost and prevent the evaporation of the Pb component during the firing process to prevent the composition variation of the porcelain composition, it is preferable to perform firing at the lowest possible temperature. From this point of view, WO ₃ is added to the porcelain composition in the present embodiment.

Further, in order to improve the electrical characteristics such as the temperature characteristic of the resonance frequency and the oscillation characteristic, 2PbO.WO
_It is necessary to segregate a Pb-W-based glass phase such as No. ₃ into the crystal body to a certain degree to densify the sintered body.
It is necessary to add WO ₃ as an oxide.

By the way, when WO ₃ alone is added to the porcelain composition and the porcelain composition is formed so that only Pb-W type is present in the crystal as a glass component, Pb-having a large particle size is formed.
Since the W-based glass component segregates as agglomerates in the crystal body, there is a risk of variations in electrical characteristics and a decrease in mechanical strength. On the other hand, if segregation of the Pb-W glass component is not formed in the crystal at all, pores remain at the crystal grain boundaries and a dense sintered body cannot be obtained. As a result, piezoelectric characteristics such as oscillation characteristics Invite decline.

For this reason, in the present embodiment, a predetermined amount of the second glass material other than the first glass material is added to the porcelain composition, whereby the segregation state of the crystal body is controlled, and the sintered body is compacted. Have been converted.

That is, by adding the second glass material other than the first glass material forming the Pb-W glass phase to the magnetic composition in an amount of 0.015 wt% to 0.040 wt%, the particle diameter is 2 μm to 40 μm. The glass phase containing the Pb-W-based glass component as a main component becomes segregated particles and is uniformly dispersed in the crystal body, whereby the pores formed at the crystal grain boundaries are filled with the segregated particles and the magnetic composition becomes dense. Can be realized.

As the second glass material, the above Pb-
Any glass material can be used as long as it can control the segregation state of the glass phase containing the W-based glass component as a main component, and examples thereof include Pb-B-based
A glass material forming each glass phase such as Pb-Si system, Pb-Ge system and Pb-P system can be used, but 50
In order to use it in a high frequency region of MHz or higher, it is necessary to polish the fired porcelain composition to a thickness of about 120 μm, and therefore it is necessary to avoid cracks, breakage and cracks during the polishing process. The bending strength P is 2 in order to avoid cracks, breakage, and cracks during the polishing process.
A mechanical strength of 00 MPa or more is required, and for that purpose, it is preferable that the second glass material contains SiO ₂ that forms a Pb—Si-based glass phase. That is, the second
The glass material of the includes at least SiO _2, Pb-B system optionally, Pb-Ge-based, _Bi 2 _O 3 forming each glass phase Pb-P system or the _like, GeO _2, P 2 _{O 5} Is preferably used.

Further, in the present embodiment, in the general formula (1), the addition weight γ of the second glass material is set to 0.015 ≦ γ ≦ 0.045 as described above, and Pb is added. The molar amounts x and y of the component and the M component are 0.790 ≦ x ≦ 0.910 and 0.060 ≦ y ≦ 0.1, respectively.
It is set to 35. Moreover, the contained molar amount x and the contained molar amount y are determined so as to satisfy the relationship of the mathematical expression (2).

X = 1- (1.5y + z) (2) Here, the variable z is set to 0 ≦ z ≦ 0.070.

The addition molar amounts α and β of MnO ₂ and WO ₃ are 0.010 ≦ α ≦ 0.032 and 0.00, respectively.
7 ≦ β ≦ 0.020 (however, 0.50 ≦ α / β ≦ 3.5
It is set to 0).

Below, the reasons for setting (1) the above-mentioned contained molar amounts x and y, variables z, (2) the added molar amounts α, β, the molar ratio α / β, and (3) the added weights γ within the above-mentioned ranges. State.

(1) The molar content x of the Pb component, the molar content y of the La component, and the variable z The Pb component is the main component of the piezoelectric ceramic composition, but the molar content x is less than 0.790 mol. In this case, the Pb component in the porcelain composition is insufficient, and it becomes impossible to obtain a desired dense porcelain composition having excellent piezoelectric characteristics. On the other hand, if the molar amount y of the Pb component exceeds 0.910 mol, the sinterability decreases.

Further, by substituting a part of the Pb component with the La component, the oscillation characteristic, that is, the third harmonic phase angle of the thickness longitudinal vibration mode (hereinafter simply referred to as “third harmonic phase angle”) θ
Can be improved, but the molar amount y of the La component is y.
When the content is less than 0.060 mol, the content is too small to contribute to the improvement of oscillation characteristics. On the other hand, when the content mol y of the La component exceeds 0.135 mol, the temperature change rate η becomes large. The temperature characteristics deteriorate.

On the other hand, in determining the molar content x of the Pb component and the molar content y of the La component, if the variable z in the above formula (2) exceeds 0.070, the sinterability decreases and the oscillation occurs. When the characteristic deteriorates and the variable z becomes less than 0, the temperature change rate of the resonance frequency (hereinafter, simply referred to as "temperature change rate")
η becomes large, which causes deterioration of frequency-temperature characteristics.

Therefore, in the present embodiment, the molar content x of the Pb component is set to 0.790 ≦ x ≦ 0.910, preferably 0.800 ≦ x ≦ 0.905, and the molar content of the La component is set. y is set to 0.060 ≦ y ≦ 0.135, preferably 0.084 ≦ y ≦ 0.092, and the variable z is set to 0 ≦ z
≦ 0.070, preferably 0 ≦ z ≦ 0.060.

(2) The molar amount α of MnO ₂ added, the molar amount β of WO ₃ and the molar ratio α / β MnO ₂ are added to the porcelain composition because they have the effect of improving oscillation characteristics. When the added molar amount α of MnO ₂ is less than 0.010 mol or exceeds 0.032 mol, the oscillation characteristics deteriorate.

Therefore, in the present embodiment, the addition molar amount α of MnO ₂ is set to 0.010 ≦ α ≦ 0.032, preferably 0.010 ≦ α ≦ 0.024.

WO ₃ is a substance that reacts with Pb oxide such as PbO to form a Pb-W glass phase, and is added to obtain a high electromechanical coupling coefficient K even at a low firing temperature. When the added molar amount β of WO ₃ is less than 0.007 mol, the glass component is not sufficiently formed and the temperature change rate η becomes large. On the other hand, the addition molar amount β of WO ₃ is 0.020mo
If it exceeds 1, the glass phase is excessively formed in the sintered body, and a dense sintered body cannot be formed, and further, the electrical characteristics vary, and the mechanical strength decreases.

Therefore, in the present embodiment, the added molar amount β of WO ₃ is set to 0.007 ≦ β ≦ 0.020, preferably 0.007 ≦ β ≦ 0.016.

Further, by adding MnO ₂ and WO ₃ in this way, a large electromechanical coupling coefficient K can be obtained while setting the firing temperature low, but the molar ratio α / β
When it exceeds 4.000, the temperature change rate η becomes large. On the other hand, since α ≧ 0.010 and β ≦ 0.020 as described above, α / β ≧ 0.500 is established. Therefore, in this embodiment, the molar ratio α / β is 0.500 ≦ α /
β ≦ 4,000, preferably 0.625 ≦ α / β ≦ 3.
It was set to 500.

That is, the addition molar amounts α and β of MnO ₂ and WO ₃ are such that the molar ratio α / β is 0.500 ≦ α / β ≦ 4.
000 (preferably 0.625 ≦ α / β ≦ 3.500)
Within the range, the above range is set.

[0054] (3) addition weight γ second glass material of the second glass material (N u _{O v)} is by segregating the glass phase mainly composed of Pb-W-based glass component in the crystal the The glass phase is uniformly dispersed in the crystal body, whereby the pores formed in the crystal grain boundaries can be filled and the sintered body can be densified. However, when the particle size of the segregated particles is less than 2 μm, the particle size is too small to fill the pores and the piezoelectric characteristics such as oscillation characteristics and temperature characteristics cannot be improved. on the other hand,
When the particle size of the segregated particles exceeds 40 μm, the volume of the segregated portion becomes large, which causes variations in the electrical characteristics among the manufactured piezoelectric elements, and also reduces the mechanical strength and causes cracks and cracks. There is a risk. Therefore, the segregated particles have a particle size of 2 μm to 40 μm, preferably 2 μm to
It is necessary to control to 20 μm.

However, when the added weight γ of the second glass material is less than 0.015 wt% in total, the segregated particles are 40 μm.
m, the mechanical strength is reduced. On the other hand, when the added weight γ of the second glass material exceeds 0.040 wt% in total, 2
Segregated particles having a particle diameter of μm or more cannot be formed, and a densified sintered body cannot be obtained. Therefore,
In the present embodiment, the addition weight γ of the second glass material is 0.0
15 ≦ γ ≦ 0.040, preferably 0.015 ≦ γ ≦
It was set to 0.020.

Next, a method for producing the above-mentioned piezoelectric ceramic composition will be described.

First, as a starting material, Pb compound, La
Compound, Ti compound, Mn compound, WO ₃ , and SiO ₂ as the second glass material (N _u O _v ), and optionally B
i ₂ O ₃ , GeO ₂ , and P ₂ O ₅ are prepared.

The Pb compound is not particularly limited as long as it is a substance that is chemically highly pure and becomes an oxide by firing. For example, a Pb oxide such as PbO or Pb ₃ O ₄ is used. You can

The La compound is not particularly limited as long as it is a substance that becomes an oxide by firing, and for example, La ₂ O is used.
₃ can be used.

Also, the Ti compound and the Mn compound are not particularly limited as long as they are substances that become oxides by firing, and Ti oxides such as TiO and TiO ₂ and further Ti (OH) ₂ can be used, M
In the case of the n compound, MnCO ₃ or MnO ₂ can be used.

Then, the powder of each of these compounds and oxides is weighed so as to have a predetermined composition. That is, the molar amount x of Pb component is 0.790 ≦ x ≦ 0.910, La
The molar content y of the component is 0.060 ≦ y ≦ 0.135, M
The addition molar amount α of nO ₂ is 0.010 ≦ α ≦ 0.032,
The addition molar amount β of WO ₃ is 0.007 ≦ β ≦ 0.020
(However, the variable z is 0.000 ≤ z ≤ 0.007, the molar ratio α / β is 0.500 ≤ α / β ≤ 4.000), and the added weight γ of the second glass material (N _u O _v ). Is 0.015 ≦
Each compound and oxide are weighed so that γ ≦ 0.040.

Next, these weighed materials are put into a ball mill containing a grinding medium such as zirconia and mixed, pure water is added, and wet grinding is carried out to prepare a slurry.

Next, the slurry thus obtained is dehydrated and dried, and then calcined at a predetermined calcination temperature,
Then, the calcined product is again charged into the ball mill, wet-milled, and dried to prepare a calcined powder.

Then, an appropriate amount of binder (for example, polyvinyl alcohol resin) is added to and mixed with the calcined powder, and dehydrated to prepare a molding powder, which is then press-molded to form a rectangular plate. Make a body. Then, finally, a firing treatment is performed in an oxygen atmosphere at a predetermined firing temperature, whereby a piezoelectric ceramic composition as a sintered body is manufactured.

The piezoelectric ceramic composition produced as described above contains 0.015 wt% to 0.05 wt% of the first glass material.
Since 40 wt% of the second glass material is added, the second glass material aggregates with the first glass material at the grain boundaries or triple points of the crystal particles to form a glass phase during the firing process. The glass phase mainly composed of a Pb-W glass component having a particle diameter of 2 μm to 40 μ is uniformly dispersed and segregated in the crystal body, and the pores of the crystal grain boundaries are filled with the glass phase. In addition, it is possible to improve the oscillation characteristics and the temperature characteristics of the resonance frequency of the manufactured piezoelectric element.

FIG. 1 is a perspective view of a piezoelectric oscillator showing an embodiment of a piezoelectric oscillator as a piezoelectric element according to the present invention. The piezoelectric oscillator includes a plate-shaped piezoelectric ceramic 1 and a piezoelectric ceramic. The body ceramic 1 includes a pair of upper and lower vibrating electrodes 2a and 2b formed on the main surface thereof, and an external electrode (not shown) electrically connected to the vibrating electrodes 2a and 2b. The vibrating electrodes 2a and 2b include excitation portions 3a and 3b formed near the center of the piezoelectric ceramic 1 and lead portions 4a that electrically connect the excitation portions 3a and 3b to the external electrodes. Four
b. The piezoelectric ceramic 1 is manufactured by cutting the above-mentioned piezoelectric ceramic composition into a plate shape.

The piezoelectric oscillator thus formed is
The piezoelectric ceramic 1 as a ceramic body has a grain size of 2
Since the glass phase of μm to 40 μm is uniformly dispersed and segregated in the crystal body, the piezoelectric ceramic 1 is densified, and therefore the third harmonic phase angle θ in the thickness longitudinal vibration mode is 81.0 deg or more. And the oscillation characteristics are excellent. In addition, the presence of such glass phase also changes the compliance, and the temperature change rate η is also −40.
In the range of ℃ to 125 ℃, it can be suppressed within ± 0.1%, and good temperature characteristics can be obtained.

The present invention is not limited to the above embodiment. In the above embodiment, part of the Pb component is L
Although the oscillation characteristics are improved by substituting with a, Nd also has an action similar to that of La. Therefore,
As a substituting element for the Pb component, instead of La alone or L
It is also preferred to use Nd with a.

In this case, the piezoelectric ceramic composition is
It will be represented by the general formula (3).

Pb _x (La / Nd) _y TiO ₃ + αMnO ₂ + βWO ₃ + γN _u O _v (3) By the research of the present inventors, L in the general formula (3) was obtained.
It has been found that when the molar content of a is smaller than the molar content of Nd, the temperature change rate η becomes large and the oscillation characteristics deteriorate. Therefore, in this case, it is necessary to adjust the respective molar amounts of La and Nd so that the molar amount of La is equal to or more than the molar amount of Nd, that is, La / Nd ≧ 1. .

Although the porcelain composition for the piezoelectric oscillator has been described in the above embodiment, the present invention is not limited to the porcelain composition for the piezoelectric oscillator, and other piezoelectric ceramic materials or piezoelectric elements may be used. It goes without saying that it is also applicable to.

Further, in the above-mentioned embodiment, the molded body is produced by performing press molding, but the molding method is not particularly limited, and other molding methods may be used. There is no end.

[0073]

EXAMPLES Next, examples of the present invention will be specifically described.

[First Embodiment] The present inventors have found that PbO,
TiO_Two, La_TwoO_Three, MnCO_Three, WO_Three, SiO _Two
Is used as a starting material, and the molar amount x of Pb component is 0.853.
mol, the molar amount y of the La component is 0.085 mol, Ti composition
Min content molar amount is 1.000 mol, MnO_TwoAdd mol of
The amount α is 0.013 mol, WO_ThreeThe added molar amount β is 0.0
The above starting materials were weighed so that the amount became 08 mol, and
Predetermined amount within the range of 0.010 wt% to 0.100 wt%
SiO_TwoWas weighed.

Each of these weighed materials had an internal volume of 9 × 10 9 in which zirconia balls as grinding media were contained.
^-3 m ³ ball mill together with pure water 4.5 kg,
The above-mentioned weighed materials are mixed and wet-milled for 2 hours to prepare a slurry, and then the slurry is dehydrated and dried at a temperature of 800-
It was calcined at 1000 ° C. for 4 hours.

Next, 0.45 kg of polyvinyl alcohol as a binder was added to the calcined powder thus obtained.
In addition, the mixture was mixed, wet pulverized, and then dried to prepare a molding powder, which was press-molded to prepare a rectangular plate-shaped molded body having a length of 35 mm, a width of 25 mm, and a thickness of 1.0 mm. Then, the molded body is heated in an oxygen atmosphere at a temperature of 1100 ° C to 1300 ° C for 3 hours.
A firing treatment was performed while holding for 6 hours, whereby 6 kinds of test pieces having different addition weights γ of SiO ₂ were prepared.

The inventors of the present invention used three-point bending type bending strength measuring machine (Rheometer CR-200D, manufactured by San Scientific Co., Ltd.) for the above-prepared six kinds of test pieces and conformed to JIS R 1601. Then, the transverse rupture strength P was measured. The molar composition ratio of the porcelain composition was measured by an inductively coupled plasma emission spectroscopic analyzer (ICP) (SPS4000 manufactured by Seiko Instruments Inc.).

FIG. 2 shows the results of bending strength measurement. The horizontal axis represents the added weight of SiO ₂ (wt%), and the vertical axis represents the bending strength P.
(MPa) is shown.

As is clear from FIG. 2, when the added weight of SiO ₂ is less than 0.015 wt%,
It has been found that when the content exceeds 0 wt%, the bending strength P becomes less than 200 MPa and sufficient mechanical strength cannot be obtained.

That is, when a piezoelectric oscillator which can be used in a high frequency region of 50 MHz or more is manufactured from a porcelain composition,
The surface is uniformly polished to a thickness of about 120 μm to reduce the thickness.
The bending strength P is required to be 200 MPa or more in order to avoid the occurrence of breakage or cracks during the polishing process. To secure the bending strength P of 200 MPa or more, addition of SiO ₂ is required. 0.015 wt as weight γ
% -0.040 wt% was found necessary.

[Second Embodiment] Next, the inventors of the present invention, similar to the first embodiment, have PbO, TiO ₂ , La ₂ O ₃ , and M.
Starting materials are nCO ₃ , WO ₃ , and SiO ₂ , and the molar amount x of Pb component is 0.853 mol, the molar amount y of La component is 0.085 mol, and the molar amount of Ti component is 1.0.
00 mol, MnO ₂ addition molar amount α is 0.013 mol, W
The above starting materials were weighed so that the added molar amount β of O ₃ was 0.008 mol, and further 0.010 wt% to 0.06
A predetermined amount of SiO ₂ was weighed within the range of 5 wt%, and a piezoelectric ceramic composition was manufactured by the same procedure as in the first embodiment.

Next, the inventors of the present invention surface-polished the above porcelain composition to a plate thickness of 250 μm, then formed electrodes, and oil temperatures of 60 ° C. to 80 ° C. and 6.0 kV / mm to 10.
An electric field was applied under the condition of 0 kV / mm to perform polarization treatment. Then, aging treatment is performed at a temperature of 150 ° C. for 1 hour, and S
Five kinds of test pieces having different addition weights γ of iO ₂ were prepared.

Then, the present inventors measured the temperature change rate η at 125 ° C. when the resonance frequency was 30 MHz (room temperature 20 ° C. standard) by using an impedance analyzer (4194A manufactured by YHP).

FIG. 3 shows the measurement results of the temperature change rate, wherein the horizontal axis shows the added weight of SiO ₂ (wt%) and the vertical axis shows the temperature change rate η (%).

As is clear from FIG. 3, it was confirmed that when the added amount of SiO ₂ exceeds 0.040 wt%, the temperature change rate η exceeds 0.10% and the temperature characteristics deteriorate.

[Third Embodiment] The present inventors
In the same manner as in the above example, PbO, TiO ₂ , La ₂ O ₃ , Mn
Starting from CO ₃ , WO ₃ , and SiO ₂ , the molar amount x of Pb component is 0.853 mol, the molar amount y of La component is 0.085 mol, and the molar amount of Ti component is 1.00.
0 mol, the molar amount α of MnO ₂ added is 0.013 mol, WO
The starting material was weighed so that the addition molar amount β of ₃ was 0.008 mol and the addition amount γ of SiO ₂ was 0.018 wt%, and the piezoelectric ceramic composition was prepared in the same procedure as in the first embodiment. Was produced.

The present inventors then observed the cross section of the prepared piezoelectric ceramic composition with a wavelength dispersive X-ray microanalyzer (JXA-8800R / RL manufactured by JEOL Ltd.).

FIG. 4 is a mapping image showing the observation results. In the figure, the white points are the glass phase containing the Pb-W glass component as the main component, and the particle size is 2 μm to 2 μm.
It was found that 0 μm of segregated particles were uniformly dispersed, whereby the pores of the grain boundaries were filled with the segregated particles, and a densified magnetic composition could be obtained.

[Fourth Embodiment] The present inventors have used SiO ₂ and Bi ₂ O ₃ as the second glass material.
Piezoelectric porcelain compositions with different added weights of glass materials and piezoelectric oscillators were produced, and the bending strength P of the produced porcelain compositions and the temperature change rate η of the piezoelectric oscillator, the triple wave phase angle θ Was measured.

That is, PbO, TiO ₂ , La
₂ O ₃ , MnCO ₃ , WO ₃ , SiO ₂ , and Bi ₂ O ₃ are used as starting materials, and the molar amount x of Pb component is 0.865 mo.
1, the molar amount y of the La component is 0.090 mol, the molar amount of the Ti component is 1.000 mol, the molar amount α of MnO ₂ added is 0.013 mol, and the molar amount β of WO ₃ added is 0.00.
8 mol, SiO ₂ and Bi ₂ O ₃ were weighed so that the added amount γ was 0.015 wt% to 0.040 wt%, and the piezoelectric ceramic composition and the piezoelectric oscillation were performed in the same procedure as in the second embodiment. Offspring were produced (Examples 1 to 4).

As a comparative example, the present inventors have made SiO 2
₂ and Bi ₂ O ₃ added weight γ is 0.010 wt in total
% And 0.045 wt%, a piezoelectric ceramic composition and a piezoelectric oscillator were produced (Comparative Examples 1 and 2).

Then, the present inventors measured the bending strength P and the temperature change rate η of each test piece in the same manner as in the first and second examples, and further measured the impedance analyzer (manufactured by YHP). 4194A) was used to measure the third harmonic phase angle θ.

Table 1 shows the results of these measurements.

[0094]

[Table 1] As is clear from Table 1, in Comparative Example 1, the added weight γ of the second glass materials SiO ₂ and Bi ₂ O ₃ was as small as 0.010 wt% in total, and particularly the added amount γ of SiO ₂ was γ.
Is as small as 0.005 wt%, so the bending strength P is 150M.
It was found to be as small as Pa and the mechanical strength was lowered.

Further, in Comparative Example 2, the added weight γ of SiO ₂ is
Is 0.035 wt% and 0.015 wt% or more of SiO
_{Since the} amount of ₂ is added, the electro-deposition strength P is 200 MPa.
And a satisfactory value was obtained, but the _second value including Bi ₂ O ₃
Since the total addition weight of the glass material of 0.045 wt% is too large, the segregation of the glass phase is not formed, and therefore the pores remain in the crystal grain boundaries and the desired dense sintered body cannot be obtained. Therefore, it was confirmed that the temperature change rate η was 0.12% and the temperature characteristics were deteriorated, and the third harmonic phase angle θ was 80.8 deg, and the oscillation characteristics were deteriorated.

On the other hand, in Examples 1 to 4, the added weight γ of SiO ₂ and Bi ₂ O ₃ was 0.015 wt% in total.
Since it is within the range of 0.040 wt%, the bending strength P is 2
00 MPa or more can be secured, the mechanical strength does not decrease even in the case of a thin piezoelectric oscillator, and the temperature change rate η is within ± 0.10%, and the triple angle phase angle θ Also became 81.0 deg or more, and it was found that it is possible to obtain a piezoelectric oscillator excellent in temperature characteristics and oscillation characteristics and suitable for use in a high frequency region.

[Fifth Embodiment] Next, the present inventors
bO, TiO ₂ , La ₂ O ₃ , MnCO ₃ , WO ₃ , S
Using iO ₂ as a starting material, each contained molar amount x, y, variable z,
Porcelain compositions having different addition amounts of α, β and addition weight γ were prepared, and a piezoelectric oscillator was prepared from the composition, and the temperature change rate η and the third harmonic phase angle θ were measured.

Table 2 shows the measurement results of the examples, and Table 3 shows the measurement results of the comparative examples.

[0099]

[Table 2]

[0100]

[Table 3] Hereinafter, each Example and Comparative Example of Tables 2 and 3 will be described.

(Example 11) The molar amount x of Pb component was 0.910 mol, and the molar amount y of La component was 0.060 m.
ol (variable z is 0), Ti component content molar amount is 1.000
mol, MnO ₂ addition molar amount α is 0.024 mol, WO ₃
Were weighed so that the addition molar amount β of was 0.016 mol and the addition weight γ of SiO ₂ was 0.020 wt%, and a piezoelectric oscillator was produced by the same procedure as in the second example.

(Example 12) The molar amount x of Pb component was 0.865 mol, and the molar amount y of La component was 0.090 m.
ol (variable z is 0), Ti component content molar amount is 1.000
mol, MnO ₂ addition molar amount α is 0.010 mol, WO ₃
Example 11 was measured such that the addition molar amount β of 0.016 mol and the addition weight γ of SiO ₂ were 0.020 wt%.
A piezoelectric oscillator was produced by the same procedure as in.

Example 13 A piezoelectric oscillator was produced in the same procedure as in Example 12 except that the added molar amount α of MnO ₂ was 0.020 mol.

(Example 14) Addition molar amount α of MnO ₂ was 0.016 mol, and addition molar amount β of WO ₃ was 0.008 mol.
A piezoelectric oscillator was produced in the same procedure as in Example 12 except for the above.

Example 15 MnO ₂ addition molar amount α is 0.024 mol, WO ₃ addition molar amount β is 0.012 mol
A piezoelectric oscillator was produced in the same procedure as in Example 12 except for the above.

(Example 16) The addition molar amount α of MnO ₂ was 0.024 mol, and the addition molar amount β of WO ₃ was 0.016 mol.
A piezoelectric oscillator was produced in the same procedure as in Example 12 except that the added weight γ of SiO ₂ and SiO ₂ was 0.040 wt%.

(Example 17) The same procedure as in Example 12 except that the content mol y of the La component was 0.060 mol (variable z was 0.045) and the addition mol amount α of MnO ₂ was 0.024 mol. Then, a piezoelectric oscillator was manufactured.

(Example 18) The molar content x of the Pb component was 0.845 mol, and the molar content y of the La component was 0.090 m.
A piezoelectric oscillator was produced in the same procedure as in Example 12 except that the ol (variable z was 0.020) and the added molar amount α of MnO ₂ was 0.024 mol.

(Example 19) The addition molar amount α of MnO ₂ was 0.028 mol, and the addition molar amount β of WO ₃ was 0.007 mol.
A piezoelectric oscillator was produced in the same procedure as in Example 18 except for the above.

(Example 20) The molar amount x of Pb component was 0.843 mol, and the molar amount y of La component was 0.105 m.
ol (variable z is 0), Ti component content molar amount is 1.000
mol, MnO ₂ addition molar amount α is 0.020 mol, WO ₃
Added mol amount β of 0.012 mol, added weight of SiO ₂ γ
Was weighed so as to be 0.020 wt%, and a piezoelectric oscillator was produced in the same procedure as in Example 11.

(Example 21) The molar amount x of Pb component was 0.820 mol, and the molar amount y of La component was 0.120 m.
A piezoelectric oscillator was produced by the same procedure as in Example 11 except that ol (variable z was 0).

(Example 22) The molar amount x of Pb component was 0.818 mol, and the molar amount y of La component was 0.075 m.
A piezoelectric oscillator was produced in the same procedure as in Example 11 except that ol (variable z was 0.070).

(Example 23) The molar content x of Pb component was 0.790 mol, and the molar content y of La component was 0.135 m.
A piezoelectric oscillator was produced in the same procedure as in Example 11 except that ol (variable z was 0.007).

(Comparative Example 11) The molar content x of the Pb component was 0.780 mol, and the molar content y of the La component was 0.135 m.
ol (variable z is 0.018), Ti component content molar amount is 1.000 mol, MnO ₂ addition molar amount α is 0.032 m
ol, WO ₃ addition molar amount β is 0.020 mol, SiO ₂
Was weighed so that the added weight γ of was 0.020 wt%,
A piezoelectric oscillator was produced in the same procedure as in Example 11 above.

(Comparative Example 12) The molar content x of Pb component was 0.900 mol, and the molar content y of La component was 0.055 m.
ol (variable z is 0.018), Ti component content molar amount is 1.000 mol, MnO ₂ addition molar amount α is 0.024 m
ol, WO ₃ addition molar amount β is 0.016 mol, SiO ₂
Was weighed so that the added weight γ of was 0.020 wt%,
A piezoelectric oscillator was produced in the same procedure as in Example 11 above.

(Comparative Example 13) The molar amount x of Pb component was 0.790 mol, and the molar amount y of La component was 0.140 m.
A piezoelectric oscillator was produced in the same procedure as in Comparative Example 12 except that ol (variable z was 0).

(Comparative Example 14) The molar amount x of Pb component was 0.865 mol, and the molar amount y of La component was 0.105 m.
A piezoelectric oscillator was produced in the same procedure as in Comparative Example 12 except that ol (variable z was −0.023).

(Comparative Example 15) The molar content x of Pb component was 0.790 mol, and the molar content y of La component was 0.090 m.
ol (variable z is 0.075), the content molar amount of Ti component is 1.000 mol, and the addition molar amount α of MnO ₂ is 0.016 m.
ol, WO ₃ addition molar amount β is 0.016 mol, SiO ₂
Was weighed so that the added weight γ of was 0.020 wt%,
A piezoelectric oscillator was produced in the same procedure as in Comparative Example 11 above.

(Comparative Example 16) The molar amount x of Pb was 0.
865 mol, the molar content y of the La component is 0.090 mol
(Variable z is 0), Ti component content molar amount is 1.000mo
l, MnO ₂ addition molar amount α is 0.008 mol, WO ₃ addition molar amount β is 0.020 mol, SiO ₂ addition weight γ
Was weighed so as to be 0.020 wt%, and the above Comparative Example 1
A piezoelectric oscillator was produced in the same procedure as in 1.

(Comparative Example 17) The molar amount x of Pb component was 0.845 mol, and the molar amount y of La component was 0.090 m.
ol (variable z is 0.020), the content molar amount of Ti component is 1.000 mol, and the addition molar amount α of MnO ₂ is 0.036 m.
ol, WO ₃ addition molar amount β is 0.016 mol, SiO ₂
Was weighed so that the added weight γ of was 0.020 wt%,
A piezoelectric oscillator was produced in the same procedure as in Comparative Example 11 above.

(Comparative Example 18) The molar amount x of Pb component was 0.865 mol, and the molar amount y of La component was 0.090 m.
ol (variable z is 0), Ti component content molar amount is 1.000
mol, MnO ₂ addition molar amount α is 0.016 mol, SiO
₂ was weighed so that the added weight γ of 0.02 wt%, and a piezoelectric oscillator was produced in the same procedure as in Comparative Example 11 above.

(Comparative Example 19) The addition molar amount α of MnO ₂ was 0.024 mol, and the addition molar amount β of WO ₃ was 0.004 mol.
A piezoelectric oscillator was produced in the same procedure as in Comparative Example 18 except that.

(Comparative Example 20) The addition molar amount α of MnO ₂ was 0.024 mol, and the addition molar amount β of WO ₃ was 0.024 mol.
A piezoelectric oscillator was produced in the same procedure as in Comparative Example 18 except that.

(Comparative Example 21) The addition molar amount α of MnO ₂ was 0.032 mol, and the addition molar amount β of WO ₃ was 0.024 mol.
A piezoelectric oscillator was produced in the same procedure as in Comparative Example 18 except that.

(Comparative Example 22) The addition molar amount α of MnO ₂ was 0.030 mol, and the addition molar amount β of WO ₃ was 0.007 mol.
A piezoelectric oscillator was produced in the same procedure as in Comparative Example 18 except that.

(Comparative Example 23) The addition molar amount α of MnO ₂ was 0.024 mol, and the addition molar amount β of WO ₃ was 0.016 mol.
A piezoelectric oscillator was produced in the same procedure as in Comparative Example 18 except that the added weight γ of SiO ₂ and SiO ₂ was 0.045 wt%.

Next, each measurement result will be described.

In Comparative Example 11, the Pb component content molar amount x was as small as 0.780 mol and a dense magnetic composition could not be obtained, so the temperature change rate η deteriorated to 0.12%,
The third-harmonic phase angle θ was also as bad as 80.8 deg, and it was found that the temperature characteristics and the oscillation characteristics deteriorate.

In Comparative Example 12, since the molar amount y of the La component was as small as 0.055 mol, the third harmonic phase angle θ was 80.
It was as small as 1deg, and the oscillation characteristics deteriorated.

In Comparative Example 13, since the content y of the La component was as large as 0.140 mol, the oscillation characteristics were good, but the temperature change rate was as large as 0.14%, and deterioration of the temperature characteristics was observed.

In Comparative Example 14, the molar amount x of the Pb component and the molar amount y of the La component are within the scope of the present invention.
Since the variable z was −0.023, which was less than 0, the temperature change rate η deteriorated.

Also in Comparative Example 15, the molar amount x of the Pb component and the molar amount y of the La component are within the scope of the present invention.
It was found that the variable z is as large as 0.075 and the sinterability of the magnetic composition is insufficient, so that the third harmonic phase angle θ is as small as 80.3 deg and the oscillation characteristics are deteriorated.

In Comparative Example 16, MnO ₂ was as small as 0.008 mol, and in Comparative Example 17, MnO ₂ was 0.036 mol, which was too large. Therefore, in all cases, the third harmonic phase angle θ was 81.
It was less than 0 deg, and deterioration of oscillation characteristics was recognized.

In Comparative Example 18, WO ₃ which should form a Pb-W glass phase was not added, and in Comparative Example 19, WO ₃ was added.
₃ was added, but the addition molar amount β was 0.0
It was found to be as small as 04 mol, so that a sufficient glass phase could not be formed, and the temperature characteristics deteriorated.

In Comparative Example 20 and Comparative Example 21, since the added molar amount β of WO ₃ was 0.024 mol, which was too large, the glass phase was excessively formed and a dense magnetic composition could not be obtained. It was found that the wave phase angle θ deteriorates to less than 81.0 deg.

In Comparative Example 22, the addition molar amount α of MnO ₂ was too large compared to the addition molar amount β of WO ₃ , and therefore the molar ratio α / β was too large, so that a dense magnetic composition could be obtained. It was found that the oscillation characteristics deteriorated to less than 81.0 deg.

In Comparative Example 23, since the additive weight γ of SiO ₂ was 0.045 wt%, which was too large, it was confirmed that segregated particles of 2 μm or more could not be formed and the temperature change rate η was deteriorated.

On the other hand, Examples 11 to 23 are all within the scope of the present invention, and the temperature change rate η is within ± 0.10%,
The third harmonic phase angle θ was 81.0 deg or more, and it was confirmed that a piezoelectric oscillator having good resonance frequency temperature characteristics and good oscillation characteristics can be obtained.

[Sixth Embodiment] The present inventors have found that PbO,
TiO ₂ , La ₂ O ₃ , Nd ₂ O ₃ , MnCO ₃ , WO
_{3. Using} SiO ₂ as a starting material, ceramic compositions having different molar contents x, y, variables z, added molar amounts α, β, and added weight γ were prepared, and piezoelectric oscillators were prepared from the ceramic compositions. Then, the temperature change rate η and the third harmonic phase angle θ were measured.

Table 4 shows the measurement results.

[0141]

[Table 4] Hereinafter, each example and comparative example of Table 4 will be described.

(Example 31) The molar amount x of Pb component was
0.865 mol, the molar content y of the La component is 0.075 m
The molar content of ol and Nd components is 0.008 mol (total
0.083 mol), (variable z is 0.011), Ti component
Content of MnO is 1.000 mol, MnO_TwoMolar amount of
α is 0.020 mol, WO_ThreeThe added molar amount β is 0.02
0 mol, SiO _TwoAdded weight γ of 0.020 wt%
And piezo-oscillate in the same procedure as in the second embodiment.
I made a child.

(Example 32) The molar amount x of Pb component was
0.865 mol, the molar content y of the La component is 0.060 m
The molar content of ol and Nd components is 0.008 mol (total
0.068 mol), (variable z is 0.034), Ti component
Content of MnO is 1.000 mol, MnO_TwoMolar amount of
α is 0.024 mol, WO_ThreeThe addition molar amount of β is 0.01
6 mol, SiO _TwoAdded weight γ of 0.020 wt%
And measure the piezoelectric oscillator in the same manner as in Example 31.
Was produced.

(Example 33) The molar amount x of Pb component was
0.845 mol, the molar content y of La component is 0.060 m
The molar content of ol and Nd components is 0.030mol (total
0.090 mol), (variable z is 0.020), Ti component
Content of MnO is 1.000 mol, MnO_TwoMolar amount of
α is 0.032 mol, WO_ThreeThe addition molar amount of β is 0.01
6 mol, SiO _TwoAdded weight γ of 0.020 wt%
And measure the piezoelectric oscillator in the same manner as in Example 31.
Was produced.

(Example 34) The molar amount x of Pb component was
0.845 mol, the molar content y of the La component is 0.045 m
The molar content of ol and Nd components is 0.025 mol (total
0.070 mol), (variable z is 0.050), Ti component
Content of MnO is 1.000 mol, MnO_TwoMolar amount of
α is 0.016mol, WO_ThreeThe added molar amount β is 0.02
0 mol, SiO _TwoAdded weight γ of 0.020 wt%
And measure the piezoelectric oscillator in the same manner as in Example 31.
Was produced.

(Example 35) The molar amount x of Pb component was
0.805mol, La component content molar amount y is 0.045m
The molar content of ol and Nd components is 0.045 mol (total
0.090 mol), (variable z is 0.060), Ti component
Content of MnO is 1.000 mol, MnO_TwoMolar amount of
α is 0.025 mol, WO_ThreeThe addition molar amount of β is 0.01
7 mol, SiO _TwoAdded weight γ of 0.020 wt%
And measure the piezoelectric oscillator in the same manner as in Example 31.
Was produced.

Comparative Example 31 The molar amount x of Pb component is
0.820 mol, the molar content y of the La component is 0.045 m
The molar content of ol and Nd components is 0.060 mol (total
0.105 mol), (variable z is 0.023), Ti component
Content of MnO is 1.000 mol, MnO_TwoMolar amount of
α is 0.024 mol, WO_ThreeThe addition molar amount of β is 0.01
6 mol, SiO _TwoAdded weight γ of 0.020 wt%
And measure the piezoelectric oscillator in the same manner as in Example 31.
Was produced.

As is apparent from Table 4, Comparative Example 31 has La / Nd of 0.750, which is less than 1.0, so that the temperature change rate η becomes large and the temperature characteristic deteriorates, and the ratio is tripled. It was confirmed that the wave phase angle θ also became smaller and the oscillation characteristics deteriorated.

On the other hand, in each of Examples 31 to 35, La / Nd was 1 or more, and the other compositions were within the scope of the present invention. Therefore, the temperature change rate η was within ± 0.10%, 3 The harmonic phase angle θ is 81.0 deg or more, and it was confirmed that a piezoelectric oscillator having good resonance frequency temperature characteristics and good oscillation characteristics can be obtained.

[0150]

As described in detail above, the piezoelectric ceramic composition according to the present invention is a piezoelectric ceramic composition in which the first glass material forming the lead-tungsten glass phase is added to the piezoelectric ceramic material. In, the second glass material other than the first glass material is 0.015% to 0.04% by weight.
Since 0% is added, it is possible to obtain a dense sintered body in which the glass phase is uniformly dispersed in the crystal body, and it is possible to obtain a piezoelectric element excellent in temperature characteristics of resonance frequency and oscillation frequency.

The piezoelectric ceramic material is Pb.
Since TiO ₃ is the main component and part of the Pb component is replaced with the La component or the La component and the Nd component, it is possible to obtain a porcelain composition having a high Curie point and a low dielectric constant. It is possible to obtain a piezoelectric element having excellent frequency temperature characteristics and oscillation characteristics in a high frequency region under a high temperature environment.

Furthermore, in the piezoelectric ceramic composition of the present invention, since the second glass material contains a silicon compound,
In addition to the above effects, excellent mechanical strength can be secured.

Further, in the piezoelectric magnetic composition of the present invention, since particles having a particle size of 2 μm to 40 μm are segregated and intervened in the crystal body, large segregated particles are not locally unevenly distributed. The pores remaining in the crystal grain boundaries are filled, and as a result, a dense sintered body is manufactured, and it is possible to improve the frequency temperature characteristics and the oscillation characteristics of the piezoelectric element to be manufactured.

[0154] Further, the piezoelectric porcelain composition of the present invention, the general formula _{Pb x M y TiO 3 + αMnO} 2 + βWO 3 + γN u O
_v (M is La, or La / Nd, N _u O _v denotes the compound composition of the second glass material) is represented by, the addition weight γ of the second glass material, by weight percent, 0 .015 ≦ γ ≦
While being set to 0.040, the molar amount x of Pb component and the molar amount y of M component are 0.790 ≦ x ≦, respectively.
0.910, 0.060 ≦ y ≦ 0.135 (where x =
1- (1.5y + z) and 0.000 ≦ z ≦ 0.0
70), and the addition molar amount α of MnO ₂ and the addition molar amount β of WO ₃ are each 0.010 ≦ α.
≦ 0.032, 0.007 ≦ β ≦ 0.020 (however,
Since 0.50 ≦ α / β ≦ 3.50) is set,
It is possible to obtain a desired piezoelectric element excellent in various piezoelectric characteristics.

By setting the molar ratio La / Nd of the La component to the Nd component to La / Nd ≧ 1.0, excellent oscillation characteristics can be maintained.

Further, in the piezoelectric element according to the present invention, since the ceramic body is formed of the above-mentioned piezoelectric ceramic composition, the piezoelectric element suitable for use in the high frequency region excellent in the temperature characteristic of the resonance frequency and the oscillation characteristic. Various piezoelectric elements such as oscillators can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a piezoelectric oscillator as a piezoelectric element according to the present invention.

FIG. 2 is a characteristic diagram showing the relationship between the added weight of SiO ₂ and bending strength.

FIG. 3 is a characteristic diagram showing the relationship between the added weight of SiO ₂ and the temperature change rate of the resonance frequency.

FIG. 4 is a mapping image showing a dispersed state of a glass phase in a porcelain composition.

[Explanation of symbols]

1 Piezoelectric ceramic (ceramic body)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masanori Kimura             2-10-10 Tenjin, Nagaokakyo, Kyoto Stock             Murata Manufacturing Co., Ltd. F term (reference) 4G031 AA07 AA09 AA11 AA18 AA19                       AA30 AA32 BA10 CA04

Claims (7)

[Claims] 1. A piezoelectric ceramic composition in which a first glass material forming a lead-tungsten glass phase is added to a piezoelectric ceramic material, wherein a second glass material other than the first glass material comprises: weight%
The piezoelectric ceramic composition is characterized by being added in an amount of 0.015% to 0.040%. 2. The piezoelectric ceramic composition according to claim 1, wherein the piezoelectric ceramic material contains lead titanate as a main component, and a part of the lead component is replaced with lanthanum or lanthanum and neodymium. object. 3. The piezoelectric ceramic composition according to claim 1 or 2, wherein the second glass material contains a silicon compound. 4. The piezoelectric ceramic composition according to claim 1, wherein particles having a particle diameter of 2 μm to 40 μm are segregated and present in the crystal body. 5. The general formula _{Pb x M y TiO 3 + αMnO} 2
+ ΒWO ₃ + γN _u O _v (M is La, or La / Nd, N
_u O _v is represented by the oxide composition of the second glass material), and the addition weight γ of the second glass material is, by weight%,
0.015 ≦ γ ≦ 0.040, and the molar amount x of the Pb component and the molar amount y of the M component are 0.790 ≦ x ≦ 0.910 and 0.060 ≦ y ≦ 0, respectively. ．
135 (however, x = 1− (1.5y + z) and 0.
000 ≦ z ≦ 0.070), and the addition molar amount α of MnO ₂ and the addition molar amount β of WO ₃ are 0.010 ≦ α ≦ 0.032, 0.0, respectively.
07 ≦ β ≦ 0.020 (however, 0.500 ≦ α / β ≦
4.000) is set, The piezoelectric ceramic composition in any one of Claim 1 thru | or 4 characterized by the above-mentioned. 6. The molar ratio La of the La component to the Nd component is La.
The piezoelectric ceramic composition according to claim 5, wherein / Nd is set to La / Nd ≧ 1.0. 7. A piezoelectric element, wherein a ceramic body is formed of the piezoelectric ceramic composition according to any one of claims 1 to 6.