US20020043653A1 - Piezoelectric ceramic composition for surface acoustic wave device and surface a coustic wave device - Google Patents
Piezoelectric ceramic composition for surface acoustic wave device and surface a coustic wave device Download PDFInfo
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- US20020043653A1 US20020043653A1 US09/935,959 US93595901A US2002043653A1 US 20020043653 A1 US20020043653 A1 US 20020043653A1 US 93595901 A US93595901 A US 93595901A US 2002043653 A1 US2002043653 A1 US 2002043653A1
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- 239000000919 ceramic Substances 0.000 title claims abstract description 55
- 238000010897 surface acoustic wave method Methods 0.000 title claims abstract description 54
- 239000000203 mixture Substances 0.000 title claims abstract description 34
- 239000000758 substrate Substances 0.000 claims description 25
- 230000007547 defect Effects 0.000 claims description 6
- 239000011148 porous material Substances 0.000 claims description 6
- 229910052745 lead Inorganic materials 0.000 claims description 4
- 230000008878 coupling Effects 0.000 abstract description 18
- 238000010168 coupling process Methods 0.000 abstract description 18
- 238000005859 coupling reaction Methods 0.000 abstract description 18
- 239000000463 material Substances 0.000 description 16
- 239000002245 particle Substances 0.000 description 11
- 239000013078 crystal Substances 0.000 description 5
- 239000002002 slurry Substances 0.000 description 4
- 238000005245 sintering Methods 0.000 description 3
- 229910052726 zirconium Inorganic materials 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 238000006731 degradation reaction Methods 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000011812 mixed powder Substances 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- 229910003327 LiNbO3 Inorganic materials 0.000 description 1
- 229910012463 LiTaO3 Inorganic materials 0.000 description 1
- 229910019714 Nb2O3 Inorganic materials 0.000 description 1
- 229910003781 PbTiO3 Inorganic materials 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 229910052593 corundum Inorganic materials 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- XMFOQHDPRMAJNU-UHFFFAOYSA-N lead(II,IV) oxide Inorganic materials O1[Pb]O[Pb]11O[Pb]O1 XMFOQHDPRMAJNU-UHFFFAOYSA-N 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000011656 manganese carbonate Substances 0.000 description 1
- 229910000016 manganese(II) carbonate Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- GNRSAWUEBMWBQH-UHFFFAOYSA-N nickel(II) oxide Inorganic materials [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000004513 sizing Methods 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 229910001845 yogo sapphire Inorganic materials 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/48—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on zirconium or hafnium oxides, zirconates, zircon or hafnates
- C04B35/49—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on zirconium or hafnium oxides, zirconates, zircon or hafnates containing also titanium oxides or titanates
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/48—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on zirconium or hafnium oxides, zirconates, zircon or hafnates
- C04B35/49—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on zirconium or hafnium oxides, zirconates, zircon or hafnates containing also titanium oxides or titanates
- C04B35/491—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on zirconium or hafnium oxides, zirconates, zircon or hafnates containing also titanium oxides or titanates based on lead zirconates and lead titanates, e.g. PZT
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/25—Constructional features of resonators using surface acoustic waves
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/20—Piezoelectric or electrostrictive devices with electrical input and mechanical output, e.g. functioning as actuators or vibrators
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/80—Constructional details
- H10N30/85—Piezoelectric or electrostrictive active materials
- H10N30/853—Ceramic compositions
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/80—Constructional details
- H10N30/85—Piezoelectric or electrostrictive active materials
- H10N30/853—Ceramic compositions
- H10N30/8548—Lead-based oxides
- H10N30/8554—Lead-zirconium titanate [PZT] based
Definitions
- the present invention relates to a piezoelectric ceramic composition used for a surface acoustic wave device.
- the present invention relates to a piezoelectric ceramic composition for a surface acoustic wave device which can improve the impedance ratio and coupling coefficient and such a surface acoustic wave device.
- an interdigital transducer composed of at least one pair of interdigital electrodes is configured on a piezoelectric substrate, and excitation and reception of the surface acoustic wave are performed by the IDT.
- a piezoelectric substrate material of the surface acoustic wave device a piezoelectric single crystal of, for example, LiTaO 3 and LiNbO 3 , or a piezoelectric ceramic primarily composed of PbTiO 3 , Pb(Ti,Zr)O 3 , etc., are used.
- a laminate in which piezoelectric thin films, such as ZnO thin films, are laminated on an insulation substrate or a piezoelectric substrate is also used as the piezoelectric substrate of the surface acoustic wave device.
- a piezoelectric substrate made of piezoelectric ceramic is preferable in order to miniaturize the surface acoustic wave device.
- Coupling coefficients required of piezoelectric substrate materials are different depending on the intended purposes, although regarding the piezoelectric single crystal, the coupling coefficient is uniquely defined based on the kind and the cut angle. That is, for a surface acoustic wave device using the piezoelectric single crystal, the piezoelectric characteristics and temperature characteristics are uniquely defined based on the kind of the single crystal and the cut angle, so that flexibility in design of devices is reduced.
- piezoelectric ceramics such as Pb(Ti,Zr)O 3 -based ceramics, have piezoelectric characteristics which can be varied over a wide range by controlling the composition.
- the piezoelectric ceramic composition for a surface acoustic wave device is represented by a formula Pb a Zr x Ti y (Ni m Mn n Nb 2/3 ) z O 3 , where:
- n fall within the ranges of:
- the piezoelectric ceramic composition for a surface acoustic wave device at least one element selected from the group consisting of Ba, Ca, and Sr may be substituted for a part of said Pb.
- a piezoelectric ceramic suitable for a piezoelectric substrate of a surface acoustic wave device is obtained.
- the surface acoustic wave device preferably utilizes a SH type surface acoustic wave.
- a grain diameter is about 3 ⁇ m or less and the sizes of pores and defects in the piezoelectric ceramic are about 3 ⁇ m or less.
- the absolute value of a change rate of resonant frequency with respect to temperature is about 100 ppm/° C. or less.
- the piezoelectric ceramic composition for a surface acoustic wave device By using the piezoelectric ceramic composition for a surface acoustic wave device according to the present invention, excellent impedance ratios can be achieved, higher frequencies can be used and the piezoelectric characteristics can be controlled over a wide range.
- the impedance ratio can be further improved.
- FIG. 1 is a graph showing changes of the electromechanical coupling coefficient kBGS with changes of z.
- FIG. 2 is a perspective view of an end face reflection type surface acoustic wave device prepared according to an embodiment of the present invention.
- a piezoelectric ceramic composition composed of at least Pb, Ni, Mn, Nb, Ti, Zr, and O and satisfying the aforementioned formula can improve the aforementioned impedance ratio could be effectively improved in a surface acoustic wave device using the aforementioned piezoelectric ceramic composition as a piezoelectric substrate.
- the piezoelectric ceramic composition according to the present invention is composed of oxides or carbonates of the elements, as primary materials, indicated by the aforementioned formula, although that may be composed of metals, other compounds or complex oxides thereof as materials.
- Each material may contain impurities, although these have little influence as long as the purity is equivalent to or more than that of first class grade chemicals.
- Al 2 O 3 and SiO 2 may be admixed therewith during manufacture, and degradation of piezoelectric characteristics does not occur by a great degree as long as the concentrations of these impurities are and 1,000 ppm or less.
- the piezoelectric ceramic obtained by sintering the piezoelectric ceramic composition comprises as a primary component an oxide having a perovskite structure. At least one element selected from the group consisting of Ba, Ca and Sr may substitute for Pb constituting A site of the perovskite structure, and in such a case, degradation of the piezoelectric characteristics is not likely to occur.
- the rate of substitution of Pb element by Sr, Ba or Ca in the piezoelectric ceramic composition is preferably specified to be within the range of about 10% by mol or less of Pb.
- a grain size is specified to be about 3 ⁇ m or less.
- the sizes of pores and defects formed in the piezoelectric ceramic are preferably specified to be about 3 ⁇ m or less.
- the absolute value of a change rate of resonant frequency with respect to temperature is preferably specified to be about 100 ppm/° C. or less.
- the piezoelectric ceramic according to the present invention is suitably used for a surface acoustic wave device using a SH type surface acoustic wave.
- the surface acoustic wave device can be further miniaturized compared to a surface acoustic wave device using a Rayleigh wave.
- powders of Pb 3 O 4 , NiO, MnCO 3 , Nb 2 O 3 , TiO 2 and ZrO 2 was prepared. These powders were weighed in order to have each of compositions as shown in the following Table 1 to Table 5, and after addition of water, wet mixing was performed with a ball mill so as to produce slurry.
- the resulting slurry was dehydrated, and the resulting mixed powder was dried with an oven and was subjected to particle sizing, thereby obtaining a piezoelectric ceramic composition.
- a binder and a dispersing agent were added to the aforementioned calcined material, and these were wet-mixed with a ball mill so as to produce a second slurry.
- the second slurry was poured into a mold having the plan shape of a square, and cast molding was performed.
- the resulting square plate-like molding was degreased at 300° C. to 600° C., and thereafter, was baked at 1,000° C. to 1,300° C. in an atmosphere of oxygen so as to produce a sintered piezoelectric ceramic.
- the surface of the resulting sintered piezoelectric ceramic was finished by lapping so as to produce a piezoelectric substrate of 5 cm by 5 cm having a thickness of 0.4 mm to 0.8 mm.
- Polarization electrodes were formed on the piezoelectric substrate produced as described above, and polarization was performed at 100° C. in oil with field intensity of 3 kV/mm. Thereafter, aging was performed at a temperature of 200° C. for 1 hour.
- a plurality of IDTs were formed on the aged piezoelectric substrate by photolithography, and each of surface acoustic wave devices was cut from the resulting piezoelectric substrate.
- the surface acoustic wave device produced as described above is shown in FIG. 2.
- an interdigital transducer (IDTs) 3 is formed on a piezoelectric substrate 2 made of the aforementioned piezoelectric ceramic composition.
- the outermost electrode fingers of IDTs 3 are flush with edges made by end faces 2 a and 2 b and the top face of the piezoelectric substrate 2 .
- the surface acoustic wave device 1 is an end face reflection type surface wave resonator using a BGS wave as a SH type surface wave. A reflector is not necessary here because of the end face reflection type. Therefore, miniaturization can be planned.
- the compositions of the materials were variously varied as described above so as to produce surface acoustic wave devices of Sample Nos. 1 to 78. Subsequently, the electromechanical coupling coefficients KBGS (%) of BGS wave, impedance ratios ATT (dB), and change rates of resonant frequency with respect to temperature (ppm/° C.) were measured. Furthermore, the particle diameter in each of the piezoelectric substrates was determined by SEM observation. The results thereof are shown in FIG. 1 and Table 1 to Table 5. Samples outside the scope of the invention are indicated by an asterisk (*).
- FIG. 1 shows changes of the electromechanical coupling coefficient with changes of y and z in the aforementioned cases.
- Table 5 shows Sample Nos. 77 and 78 in which Sr was substituted for part of the Pb in the A site. It is clear that high impedance ratios and electromechanical coupling coefficients kBGS can also be achieved in compositions in which Sr is present at the A site.
- the particle diameter of the sintered material is preferably about 3 ⁇ m or less.
- the defects and pores in the sintered material effects similar to those in the above description are exhibited, so that, as is assumed from the actions due to the changes of the particle diameter of the sintered material, the defects and pores are also preferably about 3 ⁇ m or less.
- the piezoelectric ceramic composition for a surface acoustic wave device according to the present invention can be used for surface acoustic wave devices using surface waves, such as a Rayleigh wave, other than SH type.
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Abstract
A piezoelectric ceramic composition for a surface acoustic wave device which can improve the electromechanical coupling coefficient is provided. The piezoelectric ceramic composition for a surface acoustic wave device is represented by the formula PbaZrxTiy(NimMnnNb2/3)zO3, wherein x+y+z=1, 0.93≦a≦1.02, 0.32≦x≦0.50, 0.41≦y≦0.54, 0.03≦z≦0.21 and 0.24≦m+n≦0.67.
Description
- 1. Field of the Invention
- The present invention relates to a piezoelectric ceramic composition used for a surface acoustic wave device. In particular, the present invention relates to a piezoelectric ceramic composition for a surface acoustic wave device which can improve the impedance ratio and coupling coefficient and such a surface acoustic wave device.
- 2. Description of the Related Art
- In recent years, accompanying the progress of mobile communication equipment using high frequencies, components used therein, for example, resonators and filters, have also been required for use in higher frequencies and miniaturization. As the resonators and the filters, surface acoustic wave devices have been used because of advantages in acceleration of use in higher frequencies and miniaturization.
- In a surface acoustic wave device, an interdigital transducer (IDT) composed of at least one pair of interdigital electrodes is configured on a piezoelectric substrate, and excitation and reception of the surface acoustic wave are performed by the IDT. As a piezoelectric substrate material of the surface acoustic wave device, a piezoelectric single crystal of, for example, LiTaO3 and LiNbO3, or a piezoelectric ceramic primarily composed of PbTiO3, Pb(Ti,Zr)O3, etc., are used. A laminate in which piezoelectric thin films, such as ZnO thin films, are laminated on an insulation substrate or a piezoelectric substrate is also used as the piezoelectric substrate of the surface acoustic wave device.
- When comparisons are made between the piezoelectric single crystal and the piezoelectric ceramic, the speed of sound is lower in the piezoelectric ceramic. Therefore, a piezoelectric substrate made of piezoelectric ceramic is preferable in order to miniaturize the surface acoustic wave device.
- Coupling coefficients required of piezoelectric substrate materials are different depending on the intended purposes, although regarding the piezoelectric single crystal, the coupling coefficient is uniquely defined based on the kind and the cut angle. That is, for a surface acoustic wave device using the piezoelectric single crystal, the piezoelectric characteristics and temperature characteristics are uniquely defined based on the kind of the single crystal and the cut angle, so that flexibility in design of devices is reduced.
- On the other hand, piezoelectric ceramics, such as Pb(Ti,Zr)O3-based ceramics, have piezoelectric characteristics which can be varied over a wide range by controlling the composition.
- However, when the piezoelectric ceramics were used as the piezoelectric substrates of the surface acoustic wave devices in high frequency regions exceeding 10 MHZ, there was a problem in that impedance ratios, that is, the ratios of the impedance at an anti-resonant frequency of Fa to the impedance at a resonant frequency of Fr, are small.
- Accordingly, it is an object of the present invention to provide a piezoelectric ceramic composition for a surface acoustic wave device which can achieve a high impedance ratio even in high frequency regions.
- The piezoelectric ceramic composition for a surface acoustic wave device is represented by a formula PbaZrxTiy(NimMnnNb2/3)zO3, where:
- x+y+z=1;
- 0.93≦a≦1.02;
- 0.32≦x≦0.50;
- 0.41≦y≦0.54;
- 0.03≦z≦0.21; and
- 0.24≦m+n≦0.67.
- Preferably, m and n fall within the ranges of:
- 0.46≦m+n≦0.67;
- 0.01≦m≦0.66; and
- 0.01≦n≦0.66.
- In the piezoelectric ceramic composition for a surface acoustic wave device, at least one element selected from the group consisting of Ba, Ca, and Sr may be substituted for a part of said Pb.
- By sintering the piezoelectric ceramic composition, a piezoelectric ceramic suitable for a piezoelectric substrate of a surface acoustic wave device is obtained. The surface acoustic wave device preferably utilizes a SH type surface acoustic wave. In the case, it is preferable that a grain diameter is about 3 μm or less and the sizes of pores and defects in the piezoelectric ceramic are about 3 μm or less. Further, it is preferable that the absolute value of a change rate of resonant frequency with respect to temperature is about 100 ppm/° C. or less.
- By using the piezoelectric ceramic composition for a surface acoustic wave device according to the present invention, excellent impedance ratios can be achieved, higher frequencies can be used and the piezoelectric characteristics can be controlled over a wide range.
- Therefore, a surface acoustic wave device which meets use requirements in higher frequencies and miniaturization can be provided with ease according to the present invention.
- When m+n is 0.46 or more, but 0.67 or less, m is 0.01 or more but 0.66 or less, and n is 0.01 or more but 0.66 or less, a large electromechanical coupling coefficient can be achieved.
- Furthermore, when the crystalline particle diameter is about 3 μm or less, and when sizes of the pores and defects in the sintered material are about 3 μm or less, the impedance ratio can be further improved.
- FIG. 1 is a graph showing changes of the electromechanical coupling coefficient kBGS with changes of z; and
- FIG. 2 is a perspective view of an end face reflection type surface acoustic wave device prepared according to an embodiment of the present invention.
- The present invention will be explained below in further detail using specified examples according to the present invention.
- A piezoelectric ceramic composition for a surface acoustic wave device, of the present invention is represented by a formula PbaZrxTiy(NimMnnNb2/3)zO3, wherein x+y+z=1, 0.93≦a≦1.02, 0.32≦x≦0.50, 0.41≦y≦0.54, 0.03≦z≦0.21, and 0.24≦m+n≦0.67.
- The inventors of the present invention have discovered that a piezoelectric ceramic composition composed of at least Pb, Ni, Mn, Nb, Ti, Zr, and O and satisfying the aforementioned formula can improve the aforementioned impedance ratio could be effectively improved in a surface acoustic wave device using the aforementioned piezoelectric ceramic composition as a piezoelectric substrate.
- The piezoelectric ceramic composition according to the present invention is composed of oxides or carbonates of the elements, as primary materials, indicated by the aforementioned formula, although that may be composed of metals, other compounds or complex oxides thereof as materials. Each material may contain impurities, although these have little influence as long as the purity is equivalent to or more than that of first class grade chemicals. Furthermore, Al2O3 and SiO2 may be admixed therewith during manufacture, and degradation of piezoelectric characteristics does not occur by a great degree as long as the concentrations of these impurities are and 1,000 ppm or less.
- In the present invention, when a is less than 0.93 or exceeds 1.02, sinterability is degraded so that a sintered material having sufficient strength cannot be produced due to inferior sinterability.
- When x is less than 0.32 or exceeds 0.50, the impedance ratio and the electromechanical coupling coefficient are reduced. Likewise, when y is less than 0.41, although the impedance ratio is high, the heat resistance is remarkably degraded. When y exceeds 0.54, the electromechanical coupling coefficient and the impedance ratio are reduced. Likewise, when z is less than 0.03, or exceeds 0.21, the impedance ratio and the electromechanical coupling coefficient are reduced.
- In addition, when m+n is 0.24 or less or exceeds 0.67, the sinterability is inferior, and many different phases are present, so that desired sintered material may not be produced.
- In particular, when m+n is 0.46 or more but 0.67 or less, m is 0.01 to 0.66, and n is 0.01 to 0.66, the electromechanical coupling coefficient can be effectively improved, so that this case is preferable.
- The piezoelectric ceramic obtained by sintering the piezoelectric ceramic composition comprises as a primary component an oxide having a perovskite structure. At least one element selected from the group consisting of Ba, Ca and Sr may substitute for Pb constituting A site of the perovskite structure, and in such a case, degradation of the piezoelectric characteristics is not likely to occur. Herein, the rate of substitution of Pb element by Sr, Ba or Ca in the piezoelectric ceramic composition is preferably specified to be within the range of about 10% by mol or less of Pb.
- Preferably, in the piezoelectric ceramic obtained by sintering the piezoelectric ceramic composition, a grain size is specified to be about 3 μm or less.
- Furthermore, the sizes of pores and defects formed in the piezoelectric ceramic are preferably specified to be about 3 μm or less.
- In a specified piezoelectric ceramic according to of the present invention, the absolute value of a change rate of resonant frequency with respect to temperature is preferably specified to be about 100 ppm/° C. or less.
- The piezoelectric ceramic according to the present invention is suitably used for a surface acoustic wave device using a SH type surface acoustic wave. When the SH type surface wave is used, the surface acoustic wave device can be further miniaturized compared to a surface acoustic wave device using a Rayleigh wave.
- Hereinafter preferred embodiments of the present invention will be described in more detail.
- As materials, powders of Pb3O4, NiO, MnCO3, Nb2O3, TiO2 and ZrO2 was prepared. These powders were weighed in order to have each of compositions as shown in the following Table 1 to Table 5, and after addition of water, wet mixing was performed with a ball mill so as to produce slurry.
- The resulting slurry was dehydrated, and the resulting mixed powder was dried with an oven and was subjected to particle sizing, thereby obtaining a piezoelectric ceramic composition.
- Subsequently, sized mixed powder was put in a box made of alumina, and was calcined at a temperature of 800° C. to 1,000° C. so as to produce a calcined material.
- A binder and a dispersing agent were added to the aforementioned calcined material, and these were wet-mixed with a ball mill so as to produce a second slurry. The second slurry was poured into a mold having the plan shape of a square, and cast molding was performed. The resulting square plate-like molding was degreased at 300° C. to 600° C., and thereafter, was baked at 1,000° C. to 1,300° C. in an atmosphere of oxygen so as to produce a sintered piezoelectric ceramic.
- The surface of the resulting sintered piezoelectric ceramic was finished by lapping so as to produce a piezoelectric substrate of 5 cm by 5 cm having a thickness of 0.4 mm to 0.8 mm.
- Polarization electrodes were formed on the piezoelectric substrate produced as described above, and polarization was performed at 100° C. in oil with field intensity of 3 kV/mm. Thereafter, aging was performed at a temperature of 200° C. for 1 hour.
- A plurality of IDTs were formed on the aged piezoelectric substrate by photolithography, and each of surface acoustic wave devices was cut from the resulting piezoelectric substrate. The surface acoustic wave device produced as described above is shown in FIG. 2.
- In the surface acoustic wave device1, an interdigital transducer (IDTs) 3 is formed on a
piezoelectric substrate 2 made of the aforementioned piezoelectric ceramic composition. The outermost electrode fingers of IDTs 3 are flush with edges made by end faces 2 a and 2 b and the top face of thepiezoelectric substrate 2. The surface acoustic wave device 1 is an end face reflection type surface wave resonator using a BGS wave as a SH type surface wave. A reflector is not necessary here because of the end face reflection type. Therefore, miniaturization can be planned. - In the production of the aforementioned surface acoustic wave device1, the compositions of the materials were variously varied as described above so as to produce surface acoustic wave devices of Sample Nos. 1 to 78. Subsequently, the electromechanical coupling coefficients KBGS (%) of BGS wave, impedance ratios ATT (dB), and change rates of resonant frequency with respect to temperature (ppm/° C.) were measured. Furthermore, the particle diameter in each of the piezoelectric substrates was determined by SEM observation. The results thereof are shown in FIG. 1 and Table 1 to Table 5. Samples outside the scope of the invention are indicated by an asterisk (*).
TABLE 1 particle a m n x y z kBGS ATT diameter fr-TC No. (mol) (mol) (mol) (mol) (mol) (mol) (%) (dB) (μm) (ppm/° C.) 1 1.000 0.167 0.167 0.500 0.470 0.030 29.6 41.6 3.0 42 2* 1.000 0.167 0.167 0.370 0.600 0.030 17.2 28.6 3.5 −27 3 1.000 0.167 0.167 0.485 0.465 0.050 34.8 52.3 1.5 51 4 1.000 0.167 0.167 0.488 0.463 0.050 40.7 53.3 1.6 −73 5 1.000 0.167 0.167 0.490 0.460 0.050 43.1 58.3 1.4 −122 6 1.000 0.167 0.167 0.410 0.530 0.060 24.8 49.5 1.7 103 7 1.000 0.167 0.167 0.400 0.540 0.060 23.7 47.3 1.5 −32 8* 1.000 0.167 0.167 0.390 0.550 0.060 22.1 39.5 1.7 −29 9 1.000 0.156 0.177 0.482 0.451 0.067 34.2 41.5 2.9 34 10 1.000 0.155 0.178 0.472 0.450 0.078 48.1 48.2 2.5 153 11 1.000 0.167 0.167 0.470 0.450 0.080 43.3 42.5 3.8 170 12 1.000 0.156 0.177 0.467 0.449 0.084 53.3 52.0 2.4 184 13 1.000 0.167 0.167 0.500 0.410 0.090 49.2 52.4 2.0 −100 14 1.000 0.167 0.167 0.440 0.470 0.090 45.9 49.8 2.1 79 15 1.000 0.167 0.167 0.370 0.540 0.090 29.5 43.5 2.2 15 16 1.000 0.156 0.178 0.462 0.448 0.090 54.5 54.3 2.1 98 17 1.000 0.156 0.178 0.463 0.447 0.090 59.3 53.2 2.3 80 18 1.000 0.156 0.178 0.462 0.448 0.090 56.7 56.4 2.2 124 -
TABLE 2 particle a m n x y z kBGS ATT diameter fr-TC No. (mol) (mol) (mol) (mol) (mol) (mol) (%) (dB) (μm) (ppm/° C.) 19* 1.000 0.167 0.167 0.500 0.370 0.130 40.2 43.5 2.1 −301 20 1.000 0.167 0.167 0.460 0.410 0.130 55.3 50.8 2.2 −50 21 1.000 0.167 0.167 0.400 0.470 0.130 34.2 48.9 2.0 39 22 1.000 0.167 0.167 0.330 0.540 0.130 27.4 44.3 2.0 −20 23 1.000 0.156 0.178 0.418 0.442 0.140 43.4 51.2 2.0 −19 24 1.000 0.156 0.178 0.380 0.480 0.140 30.0 49.4 2.1 21 25 1.000 0.156 0.177 0.386 0.441 0.173 33.0 46.7 2.4 15 26 1.000 0.156 0.178 0.380 0.440 0.180 32.3 45.9 2.0 22 27 1.000 0.156 0.178 0.370 0.450 0.180 32.7 50.8 2.6 51 28 1.000 0.156 0.178 0.390 0.430 0.180 37.1 51.0 2.2 −91 29 1.000 0.156 0.178 0.360 0.460 0.180 26.4 45.7 2.1 −12 30 1.000 0.156 0.178 0.350 0.450 0.200 27.1 46.5 2.3 −16 31 1.000 0.167 0.167 0.380 0.410 0.210 29.2 45.8 1.9 −31 32 1.000 0.167 0.167 0.320 0.470 0.210 25.0 41.9 2.0 21 33* 1.000 0.156 0.178 0.330 0.450 0.220 23.3 39.4 3.2 −32 34* 1.000 0.167 0.167 0.320 0.410 0.270 20.3 36.3 1.8 −30 35* 1.000 0.167 0.167 0.440 0.540 0.020 11.7 21.5 3.2 81 36 1.000 0.156 0.177 0.500 0.470 0.030 31.6 45.1 2.7 40 37 1.000 0.156 0.177 0.430 0.540 0.030 28.3 43.8 2.6 28 38 1.000 0.167 0.167 0.470 0.450 0.080 44.3 49.1 2.1 127 -
TABLE 3 particle a m n x y z kBGS ATT diameter fr-TC No. (mol) (mol) (mol) (mol) (mol) (mol) (%) (dB) (μm) (ppm/° C.) 39 0.980 0.292 0.334 0.488 0.463 0.050 58.1 54.1 1.6 −30 40 1.000 0.292 0.334 0.488 0.463 0.050 60.8 56.7 1.6 −53 41 1.020 0.292 0.334 0.488 0.463 0.050 59.0 55.3 1.5 −81 42 0.960 0.155 0.178 0.472 0.450 0.078 37.5 46.0 2.2 245 43 0.980 0.155 0.178 0.472 0.450 0.078 46.3 48.9 2.7 220 44 1.000 0.155 0.178 0.472 0.450 0.078 48.1 48.2 2.5 153 45 0.980 0.156 0.178 0.463 0.447 0.090 50.1 51.5 2.1 259 46 1.000 0.156 0.178 0.463 0.447 0.090 59.3 53.2 2.3 80 47 1.010 0.156 0.178 0.463 0.447 0.090 54.4 53.3 2.0 79 48 1.020 0.156 0.178 0.463 0.447 0.090 51.5 51.7 2.3 136 49 0.930 0.119 0.119 0.455 0.436 0.109 35.3 45.0 2.4 84 50 0.950 0.119 0.119 0.455 0.436 0.109 41.0 46.6 2.0 64 51 0.969 0.119 0.119 0.455 0.436 0.109 47.5 49.4 2.5 43 52 1.000 0.119 0.119 0.455 0.436 0.109 49.8 51.2 2.6 21 53 0.980 0.156 0.178 0.380 0.440 0.180 37.8 51.3 2.2 18 54 1.000 0.156 0.178 0.380 0.440 0.180 32.3 45.9 2.0 22 55 0.980 0.156 0.178 0.370 0.450 0.180 32.0 49.8 2.3 27 56 1.000 0.156 0.178 0.370 0.450 0.180 32.7 50.8 2.6 51 57 0.980 0.156 0.178 0.360 0.460 0.180 26.1 44.4 2.2 −20 58 1.000 0.156 0.178 0.360 0.460 0.180 26.4 45.7 2.1 −12 -
TABLE 4 particle a m n x y z kBGS ATT diameter fr-TC No. (mol) (mol) (mol) (mol) (mol) (mol) (%) (dB) (μm) (ppm/° C.) 59 1.000 0.656 0.010 0.490 0.470 0.040 50.9 58.0 2.2 101 60 1.000 0.500 0.166 0.495 0.465 0.040 52.7 53.6 2.3 −33 61 1.000 0.333 0.333 0.495 0.465 0.040 53.1 58.5 2.3 −40 62 1.000 0.160 0.500 0.495 0.465 0.040 52.0 59.0 2.4 −49 63 1.000 0.010 0.656 0.490 0.470 0.040 49.7 55.9 2.2 42 64 1.000 0.167 0.167 0.490 0.460 0.050 43.1 58.3 1.4 −122 65 1.000 0.292 0.334 0.490 0.460 0.050 63.5 59.3 1.5 −97 66 1.000 0.333 0.333 0.490 0.460 0.050 63.9 59.0 1.7 −60 67 1.000 0.167 0.167 0.488 0.463 0.050 40.7 53.3 1.6 −73 68 1.000 0.230 0.230 0.488 0.463 0.050 51.5 54.1 1.8 −61 69 1.000 0.292 0.334 0.488 0.463 0.050 60.8 56.7 1.6 −53 70 1.000 0.333 0.333 0.488 0.463 0.050 61.2 57.4 1.4 40 71 1.000 0.167 0.167 0.485 0.465 0.050 34.8 52.3 1.5 51 72 1.000 0.292 0.334 0.485 0.465 0.050 54.2 54.7 1.5 96 73 1.000 0.333 0.333 0.485 0.465 0.050 56.1 55.8 1.8 104 74 1.000 0.119 0.119 0.470 0.450 0.080 48.5 48.1 2.2 38 75 1.000 0.139 0.139 0.470 0.450 0.080 52.8 55.2 2.3 65 76* 1.000 0.167 0.167 0.470 0.450 0.080 38.2 38.4 3.8 170 -
TABLE 5 particle a m n x y z Sr kBGS ATT diameter fr-TC No. (mol) (mol) (mol) (mol) (mol) (mol) (mol) (%) (dB) (μm) (ppm/° C.) 77 0.950 0.015 0.017 0.458 0.493 0.050 0.050 51.2 58.2 1.8 −21 78 0.950 0.015 0.024 0.465 0.485 0.050 0.050 44.2 55.3 2.3 36 - Sample Nos. 1 to 38 in Tables 1 and 2 are examples in which x, y, and z are varied while a=1 and m+n=⅓ in the aforementioned formula. FIG. 1 shows changes of the electromechanical coupling coefficient with changes of y and z in the aforementioned cases.
- As is clear from FIG. 1, the electromechanical coupling coefficients vary with changes of z, and reach maximum values in the neighborhood of z=0.1. It is clear that the impedance ratios (ATT) are sufficiently large, 40 dB or more, in the range of 0.03≦z≦0.21. On the other hand, in Sample Nos. 33, 34, and 35, which are out of the range of 0.03≦z≦0.21, sinterability is degraded and the impedance ratios are reduced.
- When y>0.54, the impedance ratios are reduced, and when y<0.41, the impedance ratios and the electromechanical coupling coefficients are large, although heat resistance is degraded.
- Since x satisfies x+y+z=1, if y or z becomes out of the aforementioned preferable range as a result of selection of x, characteristics are degraded.
- As is confirmed from the results shown in Tables 1 and 2, the impedance ratios are excellent when x falls within the range of 0.32≦x≦0.50.
- In Sample Nos. 39 to 58 as shown in Table 3, the value of a is varied in the range of 0.93 to 1.02, while x, y and z fall within the aforementioned preferable ranges. As is clear from Table 3, the impedance ratios and the electromechanical coupling coefficients are not degraded by a large degree in spite of changes of a. Therefore, it is clear that excellent piezoelectric characteristics can be exhibited when a falls within the range of 0.93≦a≦1.02. When a is out of this range, sinterability is degraded.
- Table 4 shows examples of Sample Nos. 59 to 76 in which m and n are varied while x, y, and z fall within the preferable ranges determined from Tables 1 and 2. It is usually believed that the perovskite structure is stable when m+n=⅓.
- However, it is clear from the results of Sample Nos. 59 to 76 that the impedance ratios become 40 or more when m +n falls within the range of 0.24≦m+n≦0.67, and the impedance ratios are not degraded compared to that in the case where m+n =⅓. In particular, it is clear that when m and n fall within the ranges of 0.46≦m+n≦0.67, 0.01≦m≦0.66 and 0.01≦n≦0.66, the electromechanical coupling coefficients KBGS preferably become very large, e.g., 50.9% or more.
- Table 5 shows Sample Nos. 77 and 78 in which Sr was substituted for part of the Pb in the A site. It is clear that high impedance ratios and electromechanical coupling coefficients kBGS can also be achieved in compositions in which Sr is present at the A site.
- The impedance ratios are reduced for Sample Nos. 3, 13, and 76 in which particle diameters of the sintered materials exceed about 3 μm. Therefore, the particle diameter of the sintered material is preferably about 3 μm or less. Regarding defects and pores in the sintered material, effects similar to those in the above description are exhibited, so that, as is assumed from the actions due to the changes of the particle diameter of the sintered material, the defects and pores are also preferably about 3 μm or less.
- With the Samples which are within the scope of the present invention, excellent impedance ratios can be achieved and a wide range of electromechanical coupling coefficients kBGS of about 30% to about 50% can be achieved.
- In the aforementioned examples, the case where the present invention has been applied to the end face reflection type surface wave device using a SH type surface wave has been explained, although the piezoelectric ceramic composition for a surface acoustic wave device according to the present invention can be used for surface acoustic wave devices using surface waves, such as a Rayleigh wave, other than SH type.
Claims (20)
1. A piezoelectric ceramic composition for a surface acoustic wave device represented by the formula AaZrxTiy(NimMnnNb2/3)zO3, wherein:
x+y+z=1;
0.93≦a≦1.02;
0.32≦x≦0.50;
0.41≦y≦0.54;
0.03≦z≦0.21;
0.24≦m+n≦0.67; and
wherein A is Pb or the combination of Pb and at least one member of the group consisting of Ba, Ca and Sr.
2. A piezoelectric ceramic composition for a surface acoustic wave device according to claim 1 , wherein
0.46≦m+n≦0.67;
0.01≦m≦0.66; and
0.01≦n≦0.66.
3. A piezo electric ceramic composition for a surface acoustic wave device according to claim 2 , wherein A is Pb.
4. A piezoelectric ceramic composition for a surface acoustic wave device according to claim 2 , wherein A is a combination of Pb and at least one member selected from the group consisting of Ba, Ca, and Sr.
5. A piezoelectric ceramic composition for a surface acoustic wave device according to claim 4 , wherein said member of the group is Sr.
6. A piezoelectric ceramic composition for a surface acoustic wave device according to claim 1 , wherein A is Pb.
7. A piezoelectric ceramic composition for a surface acoustic wave device according to claim 1 , wherein A is a combination of Pb and at least one member selected from the group consisting of Ba, Ca, and Sr.
8. A piezoelectric ceramic composition for a surface acoustic wave device according to claim 7 , wherein said member of the group is Sr.
9. A piezoelectric ceramic comprising a sintered piezoelectric ceramic composition for a surface acoustic wave device according to claim 1 .
10. A piezoelectric ceramic according to claim 9 , having a grain diameter of about 3 μm or less.
11. A piezoelectric ceramic according to claim 10 , wherein the size of pores and defects in the piezoelectric ceramic are about 3 μm or less.
12. A piezoelectric ceramic according to claim 11 , wherein the absolute value of the change rate of resonant frequency with respect to temperature is about 100 ppm/° C. or less.
13. A piezoelectric ceramic comprising a sintered piezoelectric ceramic composition for a surface acoustic wave device according to claim 2 .
14. A piezoelectric ceramic according to claim 13 , having a grain diameter of about 3 μm or less.
15. A surface acoustic wave device comprising a piezoelectric substrate comprising the piezoelectric ceramic, according to claim 13; and an interdigital transducer on the piezoelectric substrate.
16. A surface acoustic wave device according to claim 15 , wherein the interdigital transducer is configured to generate a SH type surface acoustic wave on the piezoelectric substrate.
17. A surface acoustic wave device according to claim 16 , wherein the piezoelectric substrate has a pair of edges defining a surface on which the interdigital transducer is disposed, and outermost electrode fingers of the interdigital transducer are flush with said edges.
18. A surface acoustic wave device comprising a piezoelectric substrate comprising the piezoelectric ceramic according to claim 9; and an interdigital transducer on the piezoelectric substrate.
19. A surface acoustic wave device according to claim 18 , wherein the interdigital transducer is configured to generate a SH type surface acoustic wave on the piezoelectric substrate.
20. A surface acoustic waive device according to claim 19 , wherein the piezoelectric substrate has a pair of edges defining a surface on which the interdigital transducer is disposed, and outermost electrode fingers of the interdigital transducer are flush with said edges.
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EP1519427A3 (en) * | 2003-09-24 | 2006-04-19 | TDK Corporation | Piezoelectric ceramic composition and manufacturing the same, and piezoelectric element |
US20080036334A1 (en) * | 2004-10-01 | 2008-02-14 | Murata Manufacturing Co., Ltd. | Piezoelectric ceramic composition and piezoelectric ceramic electronic component |
US10771730B2 (en) | 2017-07-28 | 2020-09-08 | Lg Display Co., Ltd. | Display apparatus |
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DE102004002204A1 (en) * | 2004-01-15 | 2005-08-11 | Epcos Ag | ceramic material |
JPWO2005068394A1 (en) * | 2004-01-20 | 2007-09-06 | 株式会社アイエイアイ | Piezoelectric ceramic composition |
JP4578176B2 (en) * | 2004-08-20 | 2010-11-10 | 京セラ株式会社 | Piezoelectric resonator and filter |
US20090065731A1 (en) * | 2007-09-06 | 2009-03-12 | Tdk Corporation | Method for producing piezoelectric ceramic |
CN106370598A (en) * | 2016-09-07 | 2017-02-01 | 中国科学院长春光学精密机械与物理研究所 | Microsphere control device based on surface acoustic waves and manufacturing method thereof, and imaging system |
Family Cites Families (14)
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JPS5528436B2 (en) * | 1973-11-24 | 1980-07-28 | ||
JPS5264700A (en) * | 1975-11-25 | 1977-05-28 | Murata Manufacturing Co | Piezooelectric ceramic for elastic surface wave element |
KR830000021B1 (en) * | 1978-09-26 | 1983-01-29 | 엔. 부이. 필립스 글로아이람펜 파브리켄 | Composition of ceramic piezoelectric material |
JPH01122965A (en) * | 1987-11-05 | 1989-05-16 | Taiyo Yuden Co Ltd | Piezoelectric ceramics composition |
US5174971A (en) * | 1990-10-10 | 1992-12-29 | Westinghouse Electric Corp. | Continuous anion exchange chromatography for the separation of zirconium isotopes |
DE4141648C2 (en) * | 1990-12-17 | 1997-01-09 | Toshiba Kawasaki Kk | Ceramic capacitor |
JP3096920B2 (en) * | 1991-05-02 | 2000-10-10 | 株式会社トーキン | Piezoelectric ceramic composition |
JPH05221717A (en) * | 1992-02-10 | 1993-08-31 | Matsushita Electric Ind Co Ltd | Piezoelectric porcelain composition |
JP3309479B2 (en) * | 1993-02-26 | 2002-07-29 | 株式会社村田製作所 | Piezoelectric ceramic |
JP2570629B2 (en) * | 1994-09-29 | 1997-01-08 | 日本電気株式会社 | Piezoelectric ceramics and manufacturing method thereof |
JP3119101B2 (en) * | 1994-11-28 | 2000-12-18 | 株式会社村田製作所 | Piezoelectric ceramic composition |
JPH1093158A (en) * | 1996-09-17 | 1998-04-10 | Toshiba Corp | Piezoelectric material |
KR0180486B1 (en) * | 1996-12-24 | 1999-03-20 | 우덕창 | Piezoelectric ceramic composition for high frequency |
US6123867A (en) * | 1997-12-03 | 2000-09-26 | Matsushita Electric Industrial Co., Ltd. | Piezoelectric ceramic composition and piezoelectric device using the same |
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EP1519427A3 (en) * | 2003-09-24 | 2006-04-19 | TDK Corporation | Piezoelectric ceramic composition and manufacturing the same, and piezoelectric element |
US7608215B2 (en) | 2003-09-24 | 2009-10-27 | Tdk Corporation | Method of manufacturing a piezoelectric ceramic composition |
US20080036334A1 (en) * | 2004-10-01 | 2008-02-14 | Murata Manufacturing Co., Ltd. | Piezoelectric ceramic composition and piezoelectric ceramic electronic component |
US7504042B2 (en) | 2004-10-01 | 2009-03-17 | Murata Manufacturing Co., Ltd. | Piezoelectric ceramic composition and piezoelectric ceramic electronic component |
US10771730B2 (en) | 2017-07-28 | 2020-09-08 | Lg Display Co., Ltd. | Display apparatus |
US11032509B2 (en) | 2017-07-28 | 2021-06-08 | Lg Display Co., Ltd. | Display apparatus with a display area and a non-display area and including a sound generator |
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US11985444B2 (en) | 2017-07-28 | 2024-05-14 | Lg Display Co., Ltd. | Display apparatus |
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