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WO2013031715A1 - Layered piezoelectric element - Google Patents

Layered piezoelectric element Download PDF

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Publication number
WO2013031715A1
WO2013031715A1 PCT/JP2012/071554 JP2012071554W WO2013031715A1 WO 2013031715 A1 WO2013031715 A1 WO 2013031715A1 JP 2012071554 W JP2012071554 W JP 2012071554W WO 2013031715 A1 WO2013031715 A1 WO 2013031715A1
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WO
WIPO (PCT)
Prior art keywords
laminate
piezoelectric
piezoelectric ceramic
insulating layer
laminated
Prior art date
Application number
PCT/JP2012/071554
Other languages
French (fr)
Japanese (ja)
Inventor
忠男 砂原
修 川崎
Original Assignee
北陸電気工業株式会社
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Filing date
Publication date
Application filed by 北陸電気工業株式会社 filed Critical 北陸電気工業株式会社
Publication of WO2013031715A1 publication Critical patent/WO2013031715A1/en

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/15—Constructional features of resonators consisting of piezoelectric or electrostrictive material
    • H03H9/17—Constructional features of resonators consisting of piezoelectric or electrostrictive material having a single resonator
    • H03H9/178—Constructional features of resonators consisting of piezoelectric or electrostrictive material having a single resonator of a laminated structure of multiple piezoelectric layers with inner electrodes
    • 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
    • H10N30/01—Manufacture or treatment
    • H10N30/04—Treatments to modify a piezoelectric or electrostrictive property, e.g. polarisation characteristics, vibration characteristics or mode tuning
    • H10N30/045—Treatments to modify a piezoelectric or electrostrictive property, e.g. polarisation characteristics, vibration characteristics or mode tuning by polarising
    • 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
    • H10N30/50—Piezoelectric or electrostrictive devices having a stacked or multilayer structure
    • 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
    • H10N30/87—Electrodes or interconnections, e.g. leads or terminals
    • H10N30/871—Single-layered electrodes of multilayer piezoelectric or electrostrictive devices, e.g. internal electrodes
    • 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
    • H10N30/87—Electrodes or interconnections, e.g. leads or terminals
    • H10N30/872—Interconnections, e.g. connection electrodes of multilayer piezoelectric or electrostrictive devices
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R17/00—Piezoelectric transducers; Electrostrictive transducers
    • 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
    • H10N30/01—Manufacture or treatment
    • H10N30/05—Manufacture of multilayered piezoelectric or electrostrictive devices, or parts thereof, e.g. by stacking piezoelectric bodies and electrodes
    • 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 laminated piezoelectric material used for a piezoelectric vibration element.
  • a piezoelectric vibration element used for a speaker or the like As a piezoelectric vibration element used for a speaker or the like, a unimorph piezoelectric vibration element in which a laminated piezoelectric material is bonded to one surface of a diaphragm and a bimorph piezoelectric type in which a laminated piezoelectric material is bonded to both surfaces of the vibration plate. A vibration element is known.
  • the laminated piezoelectric material bonded to the diaphragm is electrically connected to an external power source using a lead wire or the like.
  • Patent Document 1 discloses that as a laminated piezoelectric material bonded to a diaphragm, a voltage is applied to a piezoelectric layer through an electrode layer, whereby polarization directions of adjacent piezoelectric layers are alternated. In other words, a material subjected to polarization treatment so as to have different directions is disclosed.
  • the number of stacked piezoelectric layers of a stacked piezoelectric body may be increased in order to increase output such as amplitude and voltage.
  • increasing the number of stacked piezoelectric layers of the laminated piezoelectric material increases the capacitance value of the laminated piezoelectric material, which is not preferable because a large load is applied to the circuit side.
  • the amount of amplitude per capacitance is reduced, and the efficiency of the piezoelectric vibration element is reduced.
  • the designed output value may not be obtained.
  • the number of piezoelectric layers stacked is increased, the number of electrode layers stacked on the stacked piezoelectric body must be increased in order to deform the piezoelectric layers.
  • This electrode layer is made of an expensive material such as an Ag—Pd alloy. Therefore, the manufacturing cost of the piezoelectric vibration element increases.
  • the piezoelectric vibration element in order to increase the output of the piezoelectric vibration element such as the amplitude and voltage, it is conceivable to configure the piezoelectric vibration element in a bimorph type.
  • the bimorph type piezoelectric vibration element it is necessary to electrically connect the laminated piezoelectric bodies bonded to both surfaces of the diaphragm to an external power source.
  • the piezoelectric vibration element when configured as a bimorph type, the piezoelectric vibration element can have a high output.
  • the soldering of the lead wire and the wiring work are performed on the laminated piezoelectric body joined to both surfaces of the vibration plate. Each of them must be performed, and the number of work steps is increased and the manufacturing cost is increased as compared with a unimorph type piezoelectric vibration element.
  • An object of the present invention is to provide a laminated piezoelectric material that can be manufactured at a high output and at a low cost.
  • Another object of the present invention is to provide a laminated piezoelectric material capable of reducing the electrostatic capacity that places a burden on the circuit.
  • Still another object of the present invention is to provide a laminated piezoelectric material capable of increasing the amplitude per capacitance.
  • the first laminated body in which a plurality of piezoelectric ceramic layers are laminated the second laminated body in which a plurality of piezoelectric ceramic layers are laminated, and the first laminated body and the second laminated body are disposed.
  • a laminated piezoelectric body is formed from the formed internal insulating layer.
  • the first laminated body and the second laminated body are configured by laminating a plurality of piezoelectric ceramic layers in which electrode layers are arranged on both surfaces and subjected to polarization treatment.
  • the plurality of piezoelectric ceramic layers of the first laminate and the plurality of piezoelectric laminate layers of the second laminate are arranged so that the amplitude mode of the first laminate and the amplitude mode of the second laminate are reversed during driving.
  • Each piezoelectric ceramic layer is polarized.
  • “the amplitude mode is reversed” means that when the first laminated body is contracting, the second laminated body is extended, and the first laminated body is extended. This means that the second laminated body performs a shrinking operation.
  • only the second laminate is supported by a flexible support plate, and the internal insulating layer is constituted by a laminate of a plurality of piezoelectric ceramic sheets not subjected to polarization treatment.
  • the portion located in the central portion in the stacking direction of the multilayer vibrator that hardly contributes to the vibration of the multilayer piezoelectric body during driving is constituted by an internal insulating layer.
  • the first laminate and the second laminate are configured so that the amplitude mode of the first laminate and the amplitude mode of the second laminate are reversed during driving.
  • the capacitance can be reduced while maintaining the output such as voltage and voltage, and the amplitude per capacitance can be increased.
  • the internal insulating layer does not require an electrode for driving.
  • the laminated piezoelectric body is apparently the same as a bimorph type piezoelectric vibration element by reversing the amplitude mode of the first laminated body and the amplitude mode of the second laminated body during driving. Since it operates, outputs such as amplitude and voltage can be made larger than those of the conventional unimorph type laminated piezoelectric material.
  • the support plate does not expand or contract even during driving, the operation of the second laminate is limited by the support plate. Therefore, the first stacked body that is not supported by the support plate operates more greatly.
  • the operation of the first laminate is not limited by the support plate.
  • the vibration of the laminated piezoelectric material is directly transmitted to the piezoelectric vibration element, the output of the piezoelectric vibration element can be easily taken out.
  • the inner insulating layer is constituted by a laminated body of a plurality of piezoelectric ceramic sheets not subjected to polarization treatment, the first laminated body and the second laminated body are formed on the piezoelectric ceramic sheet constituting the inner insulating layer.
  • the piezoelectric ceramic layer hardly contributes to the vibration of the laminated piezoelectric material during driving, the voltage is applied by the electrodes provided on both surfaces, so that the capacitance of the laminated piezoelectric material increases. Therefore, the piezoelectric ceramic layer that hardly contributes to the vibration of the laminated piezoelectric body during driving causes the capacitance of the laminated piezoelectric body to increase and places a load on the circuit, thereby reducing the performance of the laminated piezoelectric body. Therefore, the inventor made a part of the piezoelectric ceramic layer, which seems to contribute little to the vibration of the laminated piezoelectric body during driving, as an internal insulating layer to which no voltage is applied. I found that did not get smaller. The present invention is based on the results of such research by the inventors.
  • the number of the plurality of piezoelectric ceramic layers of the first laminate is equal to the number of the plurality of piezoelectric ceramic layers of the second laminate. If it does in this way, since the same laminated body can be used for the 1st laminated body and the 2nd laminated body, a laminated piezoelectric material can be manufactured more cheaply. In addition, since it is possible to configure a laminated piezoelectric body substantially symmetrically about the inner insulating layer, there is no need to consider the direction of the laminated piezoelectric body when supporting it on a support plate or the like. Can be manufactured.
  • the number of the plurality of piezoelectric ceramic layers of the first multilayer body may be configured to be larger than the number of the plurality of piezoelectric ceramic layers of the second multilayer body.
  • the support plate does not expand or contract even during driving, the operation of the second laminate is limited by the support plate. Therefore, the first stacked body that is not supported by the support plate operates more greatly. Therefore, by increasing the number of the plurality of piezoelectric ceramic layers of the first multilayer body, it is possible to increase the obtained amplitude, voltage, etc., and improve the performance of the multilayer piezoelectric body.
  • the electrical connection between the plurality of electrode layers in the first stacked body and the plurality of electrode layers in the second stacked body and an external power source can be in any form.
  • a first external insulating layer including a first pair of external electrodes is disposed on an outer surface that does not face the internal insulating layer of the first stacked body.
  • a second external insulating layer having a second pair of external electrodes is disposed on the outer surface of the second stacked body that does not face the internal insulating layer. Then, when an AC voltage is applied to the first pair of external electrodes of the first outer insulating layer, the first stacked body and the second stacked body vibrate in different amplitude modes.
  • the pair of external electrode layers, the plurality of electrode layers in the first stacked body, the plurality of electrode layers in the second stacked body, and the second pair of external electrode layers are electrically connected.
  • the plurality of piezoelectric ceramic layers and the second laminate of the first laminate using the plurality of electrode layers in the first laminate and the plurality of electrode layers in the second laminate.
  • Each of the plurality of piezoelectric ceramic layers can be polarized. Therefore, since no separate equipment is required for performing the polarization treatment, the laminated piezoelectric material can be manufactured at low cost.
  • the second outer insulating layer is supported by a flexible support plate.
  • FIG. 1 shows the structure of a piezoelectric vibration element provided with the laminated piezoelectric material of embodiment of this invention. It is the disassembled perspective view which decomposed
  • (A) And (B) is a schematic diagram of the laminated piezoelectric material as a comparative example
  • (C) And (D) is a schematic diagram of the laminated piezoelectric material as an Example.
  • surface which put together the electrostatic capacitance measured value of the comparative example 1, comparative example 2, Example 1, and Example 2, an amplitude amount, and the amplitude amount per electrostatic capacitance (amplitude amount / electrostatic capacitance).
  • (A) is a graph showing the relationship between the impedance and frequency (frequency characteristics) of Comparative Example 1 and Comparative Example 2
  • (B) shows the relationship between the impedance and frequency (frequency characteristics) of Example 1 and Example 2. It is a graph.
  • FIG. 1 is a diagram illustrating a configuration of a piezoelectric vibration element 1 including a multilayered piezoelectric body according to an embodiment of the present invention.
  • FIG. 2 is an exploded perspective view in which a main part of the piezoelectric vibration element 1 of FIG. It is.
  • the piezoelectric vibration element 1 of the present embodiment includes a support plate 3 and a laminated piezoelectric body 5 supported by the support plate 3. 1 and 2 exaggerate the thickness dimensions of the support plate 3 and the laminated piezoelectric body 5 for easy understanding.
  • the support plate 3 is formed of a flexible resin film such as FR-4 and has a rectangular shape.
  • the support plate 3 may be formed of a metal plate made of brass, nickel alloy or stainless steel.
  • the mode in which the support plate 3 supports the laminated piezoelectric body 5 is arbitrary, and in this embodiment, the laminated piezoelectric body 5 can be supported by bonding the laminated piezoelectric body 5 to the support plate 3.
  • an electrode (not shown) that is electrically connected to an external electrode of the lower laminated body 9 of the laminated piezoelectric body 5 described later is formed by printing. This electrode is electrically connected to an external AC power source using, for example, a lead wire, and supplies power to the lower laminated body 9 of the laminated piezoelectric body 5.
  • the support plate 3 is supported at both ends in the longitudinal direction by a support not shown.
  • the laminated piezoelectric body 5 is configured by laminating an upper laminated body 7, a lower laminated body 9, and an internal insulating layer 11 disposed between the upper laminated body 7 and the lower laminated body 9.
  • the upper laminate 7 constitutes the first laminate of the present invention
  • the lower laminate 9 constitutes the second laminate of the present invention.
  • the upper laminate 7 is configured by alternately laminating five electrode layers 13A to 13E and four piezoelectric ceramic layers 15A to 15D. Therefore, the piezoelectric ceramic layers 15A to 15D of the upper laminate 7 of the present embodiment have electrode layers arranged on both sides.
  • the overall shape of the upper laminate 7 is configured to be a rectangular plate having a pair of opposed short sides and a pair of opposed long sides.
  • One outer surface in the stacking direction of the upper stacked body 7 is bonded to the internal insulating layer 11.
  • An upper insulating layer 17 (first outer insulating layer) is bonded to the other outer surface of the upper stacked body 7 in the stacking direction, that is, the outer surface not facing the inner insulating layer.
  • a first side surface electrode 19 ⁇ / b> A and a second side surface electrode 19 ⁇ / b> B are provided on one long side surface of the upper stacked body 7.
  • the five electrode layers 13A to 13E are all formed using a conductive paste made of silver, palladium metal powder, glass frit, and resin.
  • the electrode layers 13A, 13C, and 13E are electrically connected to each other via the first side electrode 19A. Since the electrode layers 13A, 13C, and 13E are in contact with the first side surface electrode 19A, the overhanging portions 21A, 21C are projected so that portions facing the first side surface electrode 19A are exposed to the outside of the laminated piezoelectric body 5. And 21E, and is formed in a substantially rectangular shape. The electrode layers 13B and 13D are electrically connected to each other via the second side surface electrode 19B.
  • the electrode layers 13B and 13D are in contact with the second side surface electrode 19B, the electrode layers 13B and 13D have overhang portions 21B and 21D that protrude so that the portion facing the second side surface electrode is exposed to the outside of the multilayered piezoelectric body 5, respectively. And it is formed in the substantially rectangular shape.
  • the four piezoelectric ceramic layers 15A to 15D are formed in a rectangular shape, and are polarized in the stacking direction so that the polarization directions of adjacent piezoelectric ceramic layers sandwiching the electrode layers 13B to 13D are opposite to each other. .
  • the polarization directions of the piezoelectric ceramic layers 15A to 15D are indicated by arrows with a symbol P, respectively.
  • the upper insulating layer 17 is made of the same material as the piezoelectric ceramic layer and is formed in a plate shape having substantially the same size as the piezoelectric ceramic layer, and is joined to the other outer surface in the stacking direction of the upper stacked body 7.
  • the upper insulating layer 17 is provided with a first electrode portion 23A at one end in the longitudinal direction of the surface facing the surface to which the upper stacked body 7 is bonded, and the second electrode at the other end.
  • a portion 23B is provided.
  • the first pair of external electrodes is constituted by the first electrode portion 23A and the second electrode portion 23B.
  • the upper insulating layer 17 is not subjected to polarization treatment.
  • the lead wires R for supplying power from an external AC power source to the upper laminate 7 are connected to the first electrode portion 23A and the second electrode portion 23B, respectively.
  • the first electrode portion 23A is configured to be connected to the first side electrode 19A, and supplies power supplied from the external AC power source via the lead wire R to the first side electrode 19A.
  • the first electrode portion 23A is formed integrally with the first side electrode 19A.
  • the second electrode portion 23B is formed integrally with the second side surface electrode 19B, and supplies power supplied from the external AC power source via the lead wire R to the second side surface electrode 19B.
  • the lower laminated body 9 of the present embodiment has a configuration substantially similar to that of the upper laminated body 7 as shown in FIGS. That is, the lower laminate 9 is configured by alternately laminating five electrode layers 13F to 13J and four piezoelectric ceramic layers 15E to 15H. Therefore, the piezoelectric ceramic layers 15E to 15H of the lower laminate 9 of the present embodiment have electrode layers disposed on both sides.
  • the number of electrode layers and piezoelectric ceramic layers that constitute the lower laminate 9 may not be the same as the number of electrode layers and piezoelectric ceramic layers that constitute the upper laminate 7.
  • One outer surface in the stacking direction of the lower stacked body 9 is joined to the internal insulating layer 11.
  • a lower insulating layer 25 (second outer insulating layer) is bonded to the other outer surface of the lower stacked body 9 in the stacking direction.
  • the lower laminate 9 is provided with a third side electrode 19C and a fourth side electrode 19D.
  • the third side surface electrode 19C and the fourth side surface electrode 19D are provided on the side surface opposite to the side surface on which the first side surface electrode 19A and the second side surface electrode 19B are provided.
  • the third side electrode 19C and the fourth side electrode 19D may be provided on the same side as the side on which the first side electrode 19A and the second side electrode 19B are provided.
  • the electrode layers 13F, 13H, and 13J are electrically connected to each other via the third side surface electrode 19C. Since the electrode layers 13F, 13H, and 13J are in contact with the third side surface electrode 19C, the overhang portions 21F, 21H that protrude so that portions facing the third side surface electrode 19C are exposed to the outside of the multilayer piezoelectric body 5 are exposed. And 21J, respectively, are formed in a substantially rectangular shape.
  • the electrode layers 13G and 13I are electrically connected to each other through the fourth side surface electrode 19D.
  • the overhanging portions 21G and 21I that protrude so that the portion facing the fourth side surface electrode 19D is exposed to the outside of the multilayer piezoelectric body 5 are respectively provided. And has a substantially rectangular shape.
  • the four piezoelectric ceramic layers 15E to 15H are formed in a rectangular shape, and are polarized in the stacking direction so that the polarization directions of adjacent piezoelectric ceramic layers sandwiching the electrode layers 13G to 13I are opposite to each other. .
  • the polarization directions of the piezoelectric ceramic layers 15E to 15H are indicated by arrows with a reference symbol P.
  • the polarization processing is performed so that the polarization directions of the piezoelectric ceramic layers 15E to 15H are the same as the polarization directions of the piezoelectric ceramic layers 15A to 15D, respectively.
  • the lower insulating layer 25 is made of the same material as the piezoelectric ceramic layer and is formed in a plate shape having substantially the same size as the piezoelectric ceramic layer, and is joined to the other end surface of the lower stacked body 9 in the stacking direction.
  • the lower insulating layer 25 is provided with a third electrode portion 23C at one end in the longitudinal direction of the surface facing the surface to which the lower stacked body 9 is bonded, and the fourth electrode at the other end.
  • a portion 23D is provided.
  • the third electrode portion 23C and the fourth electrode portion 23D are connected to an electric circuit (not shown) of the support plate 3, and power supplied from an external AC power source is supplied to the third side electrode 19C via the electric circuit. And supplied to the fourth side electrode 19D.
  • the third electrode portion 23C and the fourth electrode portion 23D constitute a second pair of external electrodes.
  • the lower insulating layer 25 is not subjected to polarization treatment.
  • the internal insulating layer 11 is formed by laminating three piezoelectric ceramic layers 11A to 11C.
  • the three piezoelectric ceramic layers 11A to 11C constituting the internal insulating layer 11 of the present embodiment include the four piezoelectric ceramic layers 15A to 15D constituting the upper laminate 7 and the four piezoelectric ceramic layers constituting the lower laminate 9.
  • the same size is used using the same material as 15E-15H. Therefore, the laminated piezoelectric material 5 of the present embodiment has a total of 11 piezoelectric ceramic layers.
  • the laminated piezoelectric body 5 of the present embodiment includes a total of 13 piezoelectric ceramic layers including the upper insulating layer 17 and the lower insulating layer 25.
  • the three piezoelectric ceramic layers 11A to 11C are not subjected to polarization treatment.
  • the polarization direction of the piezoelectric ceramic layer 15D of the upper laminate 7 disposed adjacent to the internal insulating layer 11 and the polarization direction of the piezoelectric ceramic layer 15E of the lower laminate 9 are opposite to each other.
  • the upper laminated body 7 and the lower laminated body 9 are laminated
  • the upper portion during driving is used.
  • the lower laminated body 9 performs an extending operation, and the upper laminated body 7
  • the polarity of the first side electrode 19A and the polarity of the fourth side electrode 19D are the same, and the second side electrode 19B And the third side electrode 19C may be configured to have the same polarity.
  • each electrode layer and the electrode portion of the insulating layer are electrically connected using side electrodes, but through holes are provided in the piezoelectric ceramic layer, and electrode material is injected into the through holes. Then, each electrode layer and the electrode portion of the insulating layer may be electrically connected.
  • FIG. 3 shows a multilayer piezoelectric body schematically showing the arrangement state of the electrode layers of the four types of multilayer piezoelectric bodies tested. Note that FIG. 3 does not show the side electrode, the upper insulating layer, and the lower electrode layer. 3A and 3B show a laminated piezoelectric body as a comparative example.
  • the laminated piezoelectric material shown in FIG. 3A is a conventional laminated piezoelectric material in which electrode layers are provided on both surfaces of 17 piezoelectric ceramic layers (Comparative Example 1).
  • the laminated piezoelectric material of FIG. 3B is a laminated piezoelectric material in which no electrode layer is provided between the piezoelectric ceramic layers corresponding to six layers from the piezoelectric ceramic layer adjacent to the support plate 3 (Comparative Example 2).
  • FIGS. 3C and 3D show a laminated piezoelectric material as an example of the present invention.
  • the number of piezoelectric ceramic layers of the upper laminated body 7 and the lower laminated body 9 is equal to 6 layers, and the number of piezoelectric ceramic layers of the internal insulating layer 11 is 5 (Example) 1).
  • the number of the piezoelectric ceramic layers of the upper laminated body 7 is eight, the number of the piezoelectric ceramic layers of the lower laminated body 9 is four, and the piezoelectric ceramic layers of the internal insulating layer 11 are the same.
  • the number is 5 layers (Example 2).
  • the piezoelectric ceramic used in the test was a piezoelectric ceramic made of lead zirconate titanate, and had dimensions of 50 mm in length, 6 mm in width, and 0.3 mm in thickness.
  • the test was performed by joining the prepared laminated piezoelectric body to a resin support plate 3 having a length of 50 mm, a width of 6 mm, and a height of 0.5 mm, respectively, with a double-sided tape having a width of 3 mm.
  • the target value of the electrostatic capacity when an effective voltage of 8.5 V (8.5 Vrms) was applied was set to 1.7 ⁇ F.
  • FIG. 4 shows the capacitance measurement value, amplitude amount, and amplitude amount per capacitance (amplitude amount / capacitance) among the test results of Comparative Example 1, Comparative Example 2, Example 1 and Example 2. It is a summary table.
  • Comparative Example 1 which is a conventional multilayer piezoelectric body, the capacitance value was 2.91 ⁇ F and the amplitude value was 73.8 ⁇ m.
  • Comparative Example 2 the capacitance value can be lowered to 1.89 ⁇ F, and the amplitude value per capacitance can be increased to 34.07. However, the amplitude value has also decreased to 64.4 ⁇ m, and the output has become low.
  • the capacitance value is reduced to 1.75 ⁇ F and the amplitude value is increased to 74.1 ⁇ m. Therefore, the burden on the circuit can be reduced and a large output can be obtained. Yes. Therefore, the amplitude value per electrostatic capacity can be increased to 42.34, so that the efficiency of the laminated piezoelectric material is improved.
  • the capacitance value only decreased to 1.78 ⁇ F, which is slightly larger than the capacitance value of Example 1. However, the amplitude value is increased to 78.8 ⁇ m. Therefore, the amplitude value per electrostatic capacity can be increased to 44.27, so that the efficiency is improved as compared with the multilayer piezoelectric body of Example 1.
  • FIG. 5A is a graph showing the relationship between impedance and frequency (frequency-impedance characteristics) of Comparative Example 1 and Comparative Example 2
  • FIG. 5B is a graph showing the impedance and frequency of Example 1 and Example 2. It is a graph showing a relationship (frequency-impedance characteristic).
  • Comparative Example 1 which is a conventional multilayer piezoelectric body
  • the resonance impedance is 43 ⁇ at 1090 Hz.
  • the frequency characteristic of Comparative Example 2 has a resonance impedance of 40 ⁇ at 1125 Hz.
  • the resonance impedance since the resonance impedance is smaller than that in Comparative Example 1, the current for driving the laminated piezoelectric material must be increased. As a result, the load on the circuit increases. Further, since the resonance frequency is large, it is considered that the loss (power loss) is larger than that of Comparative Example 1.
  • Example 1 of the present invention the frequency-impedance characteristic showing a resonant impedance of 56 ⁇ at 1090 Hz is obtained.
  • the piezoelectric laminated body of Example 1 although the resonance frequency does not change, the impedance value is increased. Therefore, the burden on the circuit is reduced.
  • the piezoelectric laminate of Example 2 of the present invention shows frequency-impedance characteristics showing a resonance impedance of 54 ⁇ at 1040 Hz.
  • the resonance frequency since the resonance frequency is low, loss (power loss) can be reduced as compared with Comparative Example 1 which is a conventional laminated piezoelectric body.
  • the value of the resonance impedance is also increased, the load on the circuit can be reduced.
  • each electrode layer is driven by applying an AC voltage
  • the present invention can also be applied to a laminated piezoelectric body driven by a DC voltage.
  • the laminated piezoelectric body composed of a total of 11 piezoelectric ceramic layers and the laminated piezoelectric body composed of a total of 17 piezoelectric ceramic layers are shown as examples.
  • the piezoelectric ceramic layers constituting the laminated piezoelectric body are shown as examples. The number of is not limited to these.
  • the upper insulating layer, the lower insulating layer, and the inner insulating layer are constituted by the piezoelectric ceramic layers constituting the upper laminated body and the lower laminated body, it is needless to say that they may be constituted by different materials.
  • the portion located in the central portion in the stacking direction of the multilayer vibrator that hardly contributes to the vibration of the multilayer piezoelectric body at the time of driving is configured by the internal insulating layer, and the first multilayer body at the time of driving is configured.
  • the first stacked body and the second stacked body are configured so that the amplitude mode and the amplitude mode of the second stacked body are reversed. Therefore, the capacitance can be reduced while maintaining the amplitude, the amount of amplitude per capacitance can be increased, and the performance of the laminated piezoelectric body can be improved.
  • the electrode layers in the laminated piezoelectric material can be reduced, the laminated piezoelectric material can be manufactured at low cost.
  • the amplitude output can be made larger than that of a conventional unimorph type multilayer piezoelectric body.

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Abstract

Provided is a layered piezoelectric element capable of reducing the electrostatic capacity at which a circuit is loaded, and capable of increasing the amount of amplitude per electrostatic capacity. A layered piezoelectric element (5) is formed from an upper layered body (7) in which piezoelectric ceramic layers (15A to 15D) are layered, a lower layered body (9) in which piezoelectric ceramic layers (15E to 15H) are layered, and an internal insulating layer (11) arranged between the upper layered body (7) and the lower layered body (9). The piezoelectric ceramic layers of the upper layered body (7) and the lower layered body (9) are subjected to a polarization treatment so as to bring about a reversal of the amplitude mode of the upper layered body (7) and the amplitude mode of the lower layered body (9) during driving. Only the lower layered body (9) is supported by a support plate (3). The internal insulating layer (11) is not subjected to a polarization treatment.

Description

積層圧電体Multilayer piezoelectric body
　本発明は、圧電型振動素子に用いる積層圧電体に関するものである。 The present invention relates to a laminated piezoelectric material used for a piezoelectric vibration element.
　スピーカ等に用いる圧電型振動素子として、振動板の一方の面に積層圧電体を接合したユニモルフ型の圧電型振動素子及び振動板の両方の面にそれぞれ積層圧電体を接合したバイモルフ型の圧電型振動素子が知られている。振動板に接合される積層圧電体は、リード線等を用いて外部の電源と電気的に接続される。特開２０１１－４９３５２号公報（特許文献１）には、振動板に接合される積層圧電体として、電極層を通じて電圧を圧電体層に印加することにより、隣り合う圧電体層の分極方向が交互に異なる方向となるように分極処理を施したものが開示されている。 As a piezoelectric vibration element used for a speaker or the like, a unimorph piezoelectric vibration element in which a laminated piezoelectric material is bonded to one surface of a diaphragm and a bimorph piezoelectric type in which a laminated piezoelectric material is bonded to both surfaces of the vibration plate. A vibration element is known. The laminated piezoelectric material bonded to the diaphragm is electrically connected to an external power source using a lead wire or the like. Japanese Patent Laid-Open No. 2011-49352 (Patent Document 1) discloses that as a laminated piezoelectric material bonded to a diaphragm, a voltage is applied to a piezoelectric layer through an electrode layer, whereby polarization directions of adjacent piezoelectric layers are alternated. In other words, a material subjected to polarization treatment so as to have different directions is disclosed.
特開２０１１－４９３５２号公報JP 2011-49352 A
　圧電型振動素子では、振幅や電圧等の出力を大きくするために、積層圧電体の圧電体層の積層数を増やすことがある。しかしながら、積層圧電体の圧電体層の積層数を増やすと、積層圧電体の静電容量値が大きくなるため、回路側に大きな負荷がかかり好ましくない。また静電容量あたりの振幅量が小さくなり、圧電型振動素子の効率が低下する。さらに、圧電型振動素子の振幅や電圧等の出力を大きくするために、積層圧電体の圧電体層の積層数を増やしても、設計通りの出力値を得られない場合がある。 In a piezoelectric vibration element, the number of stacked piezoelectric layers of a stacked piezoelectric body may be increased in order to increase output such as amplitude and voltage. However, increasing the number of stacked piezoelectric layers of the laminated piezoelectric material increases the capacitance value of the laminated piezoelectric material, which is not preferable because a large load is applied to the circuit side. In addition, the amount of amplitude per capacitance is reduced, and the efficiency of the piezoelectric vibration element is reduced. Furthermore, even if the number of stacked piezoelectric layers of the laminated piezoelectric body is increased in order to increase the output such as the amplitude and voltage of the piezoelectric vibration element, the designed output value may not be obtained.
　また、圧電体層の積層数を増やすと、圧電体層を変形させるために積層圧電体に積層される電極層の数も増やさなければならない。この電極層は、例えばＡｇ－Ｐｄ合金等の高価な材料により構成されている。そのため、圧電型振動素子の製造コストが増加する。 Also, if the number of piezoelectric layers stacked is increased, the number of electrode layers stacked on the stacked piezoelectric body must be increased in order to deform the piezoelectric layers. This electrode layer is made of an expensive material such as an Ag—Pd alloy. Therefore, the manufacturing cost of the piezoelectric vibration element increases.
　なお、圧電型振動素子の振幅や電圧等の出力を大きくするために、圧電型振動素子をバイモルフ型に構成することも考えられる。しかしながら、バイモルフ型の圧電型振動素子は、振動板の両面に接合された積層圧電体を、それぞれ外部の電源と電気的に接続する必要がある。そのため、圧電型振動素子をバイモルフ型に構成すると、圧電型振動素子を高出力とすることはできるが、例えばリード線の半田付け及び配線の作業を振動板の両面に接合された積層圧電体にそれぞれ行わなければならず、ユニモルフ型の圧電振動素子に比べて、作業工程数が多くなり、製造コストが高くなる。 In addition, in order to increase the output of the piezoelectric vibration element such as the amplitude and voltage, it is conceivable to configure the piezoelectric vibration element in a bimorph type. However, in the bimorph type piezoelectric vibration element, it is necessary to electrically connect the laminated piezoelectric bodies bonded to both surfaces of the diaphragm to an external power source. For this reason, when the piezoelectric vibration element is configured as a bimorph type, the piezoelectric vibration element can have a high output. However, for example, the soldering of the lead wire and the wiring work are performed on the laminated piezoelectric body joined to both surfaces of the vibration plate. Each of them must be performed, and the number of work steps is increased and the manufacturing cost is increased as compared with a unimorph type piezoelectric vibration element.
　本発明の目的は、高出力で安価に製造することができる積層圧電体を提供することにある。 An object of the present invention is to provide a laminated piezoelectric material that can be manufactured at a high output and at a low cost.
　本発明の他の目的は、回路に負担のかかる静電容量を小さくすることができる積層圧電体を提供することにある。 Another object of the present invention is to provide a laminated piezoelectric material capable of reducing the electrostatic capacity that places a burden on the circuit.
　本発明のさらに他の目的は、静電容量あたりの振幅量を大きくすることができる積層圧電体を提供することにある。 Still another object of the present invention is to provide a laminated piezoelectric material capable of increasing the amplitude per capacitance.
　本発明では、複数の圧電セラミック層を積層した第１の積層体と、複数の圧電セラミック層を積層した第２の積層体と、第１の積層体と第２の積層体との間に配置された内部絶縁層とから積層圧電体を構成する。第１の積層体及び第２の積層体は、両面に電極層が配置され且つ分極処理が施された複数の圧電セラミック層を積層して構成する。そして、駆動時の第１の積層体の振幅モードと第２の積層体の振幅モードとが逆になるように、第１の積層体の複数の圧電セラミックス層及び第２の積層体の複数の圧電セラミックス層をそれぞれ分極処理する。本願明細書において「振幅モードが逆になる」とは、第１の積層体が縮み動作をしているときに第２の積層体が伸び動作をし、第１の積層体が伸び動作をしているときに第２の積層体が縮み動作をすることを意味する。そして第２の積層体のみを可撓性のある支持プレートにより支持するとともに、内部絶縁層を分極処理が施されてない複数の圧電セラミックシートの積層体によって構成する。 In the present invention, the first laminated body in which a plurality of piezoelectric ceramic layers are laminated, the second laminated body in which a plurality of piezoelectric ceramic layers are laminated, and the first laminated body and the second laminated body are disposed. A laminated piezoelectric body is formed from the formed internal insulating layer. The first laminated body and the second laminated body are configured by laminating a plurality of piezoelectric ceramic layers in which electrode layers are arranged on both surfaces and subjected to polarization treatment. Then, the plurality of piezoelectric ceramic layers of the first laminate and the plurality of piezoelectric laminate layers of the second laminate are arranged so that the amplitude mode of the first laminate and the amplitude mode of the second laminate are reversed during driving. Each piezoelectric ceramic layer is polarized. In this specification, “the amplitude mode is reversed” means that when the first laminated body is contracting, the second laminated body is extended, and the first laminated body is extended. This means that the second laminated body performs a shrinking operation. Then, only the second laminate is supported by a flexible support plate, and the internal insulating layer is constituted by a laminate of a plurality of piezoelectric ceramic sheets not subjected to polarization treatment.
　本発明では、駆動時の積層圧電体の振動にほとんど寄与しない積層振動体の積層方向の中央部に位置する部分は、内部絶縁層により構成される。また本発明では、駆動時の第１の積層体の振幅モードと第２の積層体の振幅モードが逆になるように、第１の積層体及び第２の積層体を構成することにより、振幅や電圧等の出力を維持したまま静電容量を低下させることができ、静電容量あたりの振幅量を大きくすることができる。その結果、本発明によれば従来よりも、積層圧電体の性能を高くすることができる。また内部絶縁層には、駆動するための電極が不要である。そのため、電極層を減らすことができるので、積層圧電体を安価に製造することができる。なお本発明では、駆動時の第１の積層体の振幅モードと第２の積層体の振幅モードを逆にすることにより、積層圧電体は、見掛け上バイモルフ型の圧電型振動素子と同じように動作するので、従来のユニモルフ型の積層圧電体よりも振幅や電圧等の出力を大きくすることができる。 In the present invention, the portion located in the central portion in the stacking direction of the multilayer vibrator that hardly contributes to the vibration of the multilayer piezoelectric body during driving is constituted by an internal insulating layer. Further, in the present invention, the first laminate and the second laminate are configured so that the amplitude mode of the first laminate and the amplitude mode of the second laminate are reversed during driving. The capacitance can be reduced while maintaining the output such as voltage and voltage, and the amplitude per capacitance can be increased. As a result, according to the present invention, the performance of the multilayered piezoelectric body can be improved as compared with the prior art. The internal insulating layer does not require an electrode for driving. As a result, the number of electrode layers can be reduced, and the laminated piezoelectric material can be manufactured at low cost. In the present invention, the laminated piezoelectric body is apparently the same as a bimorph type piezoelectric vibration element by reversing the amplitude mode of the first laminated body and the amplitude mode of the second laminated body during driving. Since it operates, outputs such as amplitude and voltage can be made larger than those of the conventional unimorph type laminated piezoelectric material.
　また、支持プレートは駆動時であっても伸縮しないため、第２の積層体は、支持プレートによって動作が制限される。そのため、支持プレートによって支持されない第１の積層体の方が大きく動作する。本発明では、第２の積層体のみを可撓性のある支持プレートにより支持しているので、第１の積層体は支持プレートにより動作が制限されない。また、積層圧電体の振動が直接圧電型振動素子に伝達するので、圧電型振動素子の出力の取出が容易になる。さらに、内部絶縁層を分極処理が施されてない複数の圧電セラミックシートの積層体によって構成しているので、内部絶縁層を構成する圧電セラミックシートに、第１の積層体及び第２の積層体を構成する分極処理をする前の圧電セラミック層を用いることができる。そのため、内部絶縁層を構成するために別の材料を準備する必要がなくなるので、積層圧電体を安価に製造することができる。 Also, since the support plate does not expand or contract even during driving, the operation of the second laminate is limited by the support plate. Therefore, the first stacked body that is not supported by the support plate operates more greatly. In the present invention, since only the second laminate is supported by the flexible support plate, the operation of the first laminate is not limited by the support plate. In addition, since the vibration of the laminated piezoelectric material is directly transmitted to the piezoelectric vibration element, the output of the piezoelectric vibration element can be easily taken out. Further, since the inner insulating layer is constituted by a laminated body of a plurality of piezoelectric ceramic sheets not subjected to polarization treatment, the first laminated body and the second laminated body are formed on the piezoelectric ceramic sheet constituting the inner insulating layer. It is possible to use a piezoelectric ceramic layer that is not subjected to the polarization treatment that constitutes. For this reason, it is not necessary to prepare another material for forming the internal insulating layer, so that the laminated piezoelectric material can be manufactured at low cost.
　ユニモルフ型の積層圧電体では、従来、全ての圧電セラミック層が振動に寄与していると考えられていたため、従来の積層圧電体は、電圧を印加することにより駆動する圧電セラミック層のみから構成されており、内部に絶縁層を含んでいない。従って、全ての圧電セラミック層が同じ振幅モードとなるように構成されている。しかしながら発明者は、設計通りの出力値が得られない原因を種々検討していく中で、積層された複数の圧電セラミック層のうち、一部の圧電セラミック層は、駆動時の積層圧電体の振動にほとんど寄与していないことを発見した。圧電セラミック層は、駆動時の積層圧電体の振動にほとんど寄与しなくとも、両面に設けられた電極により電圧が印加されているため、積層圧電体の静電容量は増加する。従って、駆動時の積層圧電体の振動にほとんど寄与しない圧電セラミック層は、積層圧電体の静電容量を増加させて回路に負荷をかける原因となり、積層圧電体の性能が低下する。そこで発明者は、駆動時の積層圧電体の振動にほとんど寄与しないと思われる圧電セラミック層の一部を、電圧が印加されない内部絶縁層としたところ、静電容量が低下することと、振幅値が小さくならないことを見いだした。本発明は、発明者のこのような研究の結果に基づくものである。 In unimorph multilayer piezoelectric materials, all piezoelectric ceramic layers were conventionally thought to contribute to vibration, so conventional multilayer piezoelectric materials consist of only piezoelectric ceramic layers that are driven by applying voltage. And does not include an insulating layer inside. Accordingly, all the piezoelectric ceramic layers are configured to have the same amplitude mode. However, the inventor has been studying various reasons why the output value as designed cannot be obtained. Among the plurality of laminated piezoelectric ceramic layers, some of the piezoelectric ceramic layers are formed by the laminated piezoelectric material during driving. I found that it hardly contributes to vibration. Even if the piezoelectric ceramic layer hardly contributes to the vibration of the laminated piezoelectric material during driving, the voltage is applied by the electrodes provided on both surfaces, so that the capacitance of the laminated piezoelectric material increases. Therefore, the piezoelectric ceramic layer that hardly contributes to the vibration of the laminated piezoelectric body during driving causes the capacitance of the laminated piezoelectric body to increase and places a load on the circuit, thereby reducing the performance of the laminated piezoelectric body. Therefore, the inventor made a part of the piezoelectric ceramic layer, which seems to contribute little to the vibration of the laminated piezoelectric body during driving, as an internal insulating layer to which no voltage is applied. I found that did not get smaller. The present invention is based on the results of such research by the inventors.
　第１の積層体の複数の圧電セラミック層の数と第２の積層体の複数の圧電セラミック層の数とが等しくなるように構成してもよい。このようにすると、第１の積層体と第２の積層体に同じ積層体を用いることができるので、積層圧電体をより安価に製造することができる。また、内分絶縁層を中心として略面対称に積層圧電体を構成することができるので、支持プレート等に支持する際に積層圧電体の方向を考慮する必要がなくなるので、積層圧電体を簡単に製造することができる。 It may be configured such that the number of the plurality of piezoelectric ceramic layers of the first laminate is equal to the number of the plurality of piezoelectric ceramic layers of the second laminate. If it does in this way, since the same laminated body can be used for the 1st laminated body and the 2nd laminated body, a laminated piezoelectric material can be manufactured more cheaply. In addition, since it is possible to configure a laminated piezoelectric body substantially symmetrically about the inner insulating layer, there is no need to consider the direction of the laminated piezoelectric body when supporting it on a support plate or the like. Can be manufactured.
　積層圧電体の性能をより向上させるために、第１の積層体の複数の圧電セラミック層の数が、第２の積層体の複数の圧電セラミック層の数よりも多くなるように構成することが好ましい。支持プレートは駆動時であっても伸縮しないため、第２の積層体は、支持プレートによって動作が制限される。そのため、支持プレートによって支持されない第１の積層体の方が大きく動作する。そこで、第１の積層体の複数の圧電セラミック層の数を多くすることにより、得られる振幅や電圧等をより大きくして、積層圧電体の性能を向上させることができる。 In order to further improve the performance of the multilayer piezoelectric body, the number of the plurality of piezoelectric ceramic layers of the first multilayer body may be configured to be larger than the number of the plurality of piezoelectric ceramic layers of the second multilayer body. preferable. Since the support plate does not expand or contract even during driving, the operation of the second laminate is limited by the support plate. Therefore, the first stacked body that is not supported by the support plate operates more greatly. Therefore, by increasing the number of the plurality of piezoelectric ceramic layers of the first multilayer body, it is possible to increase the obtained amplitude, voltage, etc., and improve the performance of the multilayer piezoelectric body.
　第１の積層体中の複数の電極層及び第２の積層体中の複数の電極層と外部の電源との電気的な接続は、任意の態様とすることができる。例えば、第１の積層体の内部絶縁層と対向しない外面に、第１の一対の外部電極を備えた第１の外部絶縁層を配置する。第２の積層体の内部絶縁層と対向しない外面には、第２の一対の外部電極を備えた第２の外部絶縁層を配置する。そして、第１の外部絶縁層の第１の一対の外部電極に交流電圧が印加されたときに、第１の積層体及び第２の積層体が異なる振幅モードで振動するように、第１の一対の外部電極層と、第１の積層体中の複数の電極層と、第２の積層体中の複数の電極層と、第２の一対の外部電極層とを電気的に接続する。このように構成すると、第１の積層体中の複数の電極層及び第２の積層体中の複数の電極層を用いて第１の積層体の複数の圧電セラミックス層及び第２の積層体の複数の圧電セラミックス層をそれぞれ分極処理することができる。そのため、分極処理をするために別個の設備を必要としないので、積層圧電体を安価に製造することができる。なおこの場合には、第２の外部絶縁層を、可撓性のある支持プレートにより支持する。 The electrical connection between the plurality of electrode layers in the first stacked body and the plurality of electrode layers in the second stacked body and an external power source can be in any form. For example, a first external insulating layer including a first pair of external electrodes is disposed on an outer surface that does not face the internal insulating layer of the first stacked body. A second external insulating layer having a second pair of external electrodes is disposed on the outer surface of the second stacked body that does not face the internal insulating layer. Then, when an AC voltage is applied to the first pair of external electrodes of the first outer insulating layer, the first stacked body and the second stacked body vibrate in different amplitude modes. The pair of external electrode layers, the plurality of electrode layers in the first stacked body, the plurality of electrode layers in the second stacked body, and the second pair of external electrode layers are electrically connected. With this configuration, the plurality of piezoelectric ceramic layers and the second laminate of the first laminate using the plurality of electrode layers in the first laminate and the plurality of electrode layers in the second laminate. Each of the plurality of piezoelectric ceramic layers can be polarized. Therefore, since no separate equipment is required for performing the polarization treatment, the laminated piezoelectric material can be manufactured at low cost. In this case, the second outer insulating layer is supported by a flexible support plate.
本発明の実施の形態の積層圧電体を備える圧電型振動素子の構成を示す図である。It is a figure which shows the structure of a piezoelectric vibration element provided with the laminated piezoelectric material of embodiment of this invention. 図１に示す圧電型振動素子の要部を分解した分解斜視図である。It is the disassembled perspective view which decomposed | disassembled the principal part of the piezoelectric type vibration element shown in FIG. （Ａ）及び（Ｂ）は比較例としての積層圧電体の模式図であり、（Ｃ）及び（Ｄ）は実施例としての積層圧電体の模式図である。(A) And (B) is a schematic diagram of the laminated piezoelectric material as a comparative example, (C) And (D) is a schematic diagram of the laminated piezoelectric material as an Example. 比較例１、比較例２、実施例１及び実施例２の静電容量測定値、振幅量及び静電容量あたりの振幅量（振幅量／静電容量）をまとめた表である。It is the table | surface which put together the electrostatic capacitance measured value of the comparative example 1, comparative example 2, Example 1, and Example 2, an amplitude amount, and the amplitude amount per electrostatic capacitance (amplitude amount / electrostatic capacitance). （Ａ）は比較例１及び比較例２のインピーダンスと周波数の関係（周波数特性）を表すグラフであり、（Ｂ）は実施例１及び実施例２のインピーダンスと周波数の関係（周波数特性）を表すグラフである。(A) is a graph showing the relationship between the impedance and frequency (frequency characteristics) of Comparative Example 1 and Comparative Example 2, and (B) shows the relationship between the impedance and frequency (frequency characteristics) of Example 1 and Example 2. It is a graph.
　以下、図面を参照して本発明の実施の形態について説明する。図１は、本発明の実施の形態の積層圧電体を備える圧電型振動素子１の構成を示す図であり、図２は、図１の圧電型振動素子１の要部を分解した分解斜視図である。図１及び図２に示すように、本実施の形態の圧電型振動素子１は、支持プレート３と、支持プレート３により支持される積層圧電体５とを備えている。なお、図１及び図２は、理解を容易にするため、支持プレート３及び積層圧電体５の厚み寸法を誇張して描いている。支持プレート３は、ＦＲ－４等の可撓性を有する樹脂フィルムによって形成されており、矩形状を有している。なお支持プレート３は、真鍮、ニッケル合金またはステンレスからなる金属板によって形成してもよい。支持プレート３が積層圧電体５を支持する態様は任意であり、本実施の形態では支持プレート３に積層圧電体５を接合することにより、積層圧電体５を支持することができる。支持プレート３の積層圧電体５が接合される面には、後述する積層圧電体５の下部積層体９の外部電極と電気的に接続される図示しない電極が印刷により形成されている。この電極は、例えばリード線を用いて外部の交流電源と電気的に接続されて、積層圧電体５の下部積層体９に電力を供給する。支持プレート３は、長手方向の両端部が図示しない支持体により支持される。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of a piezoelectric vibration element 1 including a multilayered piezoelectric body according to an embodiment of the present invention. FIG. 2 is an exploded perspective view in which a main part of the piezoelectric vibration element 1 of FIG. It is. As shown in FIGS. 1 and 2, the piezoelectric vibration element 1 of the present embodiment includes a support plate 3 and a laminated piezoelectric body 5 supported by the support plate 3. 1 and 2 exaggerate the thickness dimensions of the support plate 3 and the laminated piezoelectric body 5 for easy understanding. The support plate 3 is formed of a flexible resin film such as FR-4 and has a rectangular shape. The support plate 3 may be formed of a metal plate made of brass, nickel alloy or stainless steel. The mode in which the support plate 3 supports the laminated piezoelectric body 5 is arbitrary, and in this embodiment, the laminated piezoelectric body 5 can be supported by bonding the laminated piezoelectric body 5 to the support plate 3. On the surface of the support plate 3 to which the laminated piezoelectric body 5 is bonded, an electrode (not shown) that is electrically connected to an external electrode of the lower laminated body 9 of the laminated piezoelectric body 5 described later is formed by printing. This electrode is electrically connected to an external AC power source using, for example, a lead wire, and supplies power to the lower laminated body 9 of the laminated piezoelectric body 5. The support plate 3 is supported at both ends in the longitudinal direction by a support not shown.
　積層圧電体５は、上部積層体７と、下部積層体９と、上部積層体７と下部積層体９との間に配置された内部絶縁層１１とを積層して構成されている。本実施の形態においては、上部積層体７が本発明の第１の積層体を構成し、下部積層体９が本発明の第２の積層体を構成している。 The laminated piezoelectric body 5 is configured by laminating an upper laminated body 7, a lower laminated body 9, and an internal insulating layer 11 disposed between the upper laminated body 7 and the lower laminated body 9. In the present embodiment, the upper laminate 7 constitutes the first laminate of the present invention, and the lower laminate 9 constitutes the second laminate of the present invention.
　上部積層体７は、５つの電極層１３Ａ～１３Ｅと、４つの圧電セラミック層１５Ａ～１５Ｄが交互に積層されて構成されている。従って本実施の形態の上部積層体７の圧電セラミックス層１５Ａ～１５Ｄは、それぞれ両面に電極層が配置されている。上部積層体７の形状は、対向する一対の短辺と対向する一対の長辺とを有する矩形の板状となるように全体が構成されている。上部積層体７の積層方向の一方の外面は、内部絶縁層１１と接合されている。また上部積層体７の積層方向の他方の外面、すなわち内部絶縁層と対向しない外面には、上部絶縁層１７（第１の外部絶縁層）が接合されている。上部積層体７の一つの長辺側の側面には、第１の側面電極１９Ａ及び第２の側面電極１９Ｂが設けられている。 The upper laminate 7 is configured by alternately laminating five electrode layers 13A to 13E and four piezoelectric ceramic layers 15A to 15D. Therefore, the piezoelectric ceramic layers 15A to 15D of the upper laminate 7 of the present embodiment have electrode layers arranged on both sides. The overall shape of the upper laminate 7 is configured to be a rectangular plate having a pair of opposed short sides and a pair of opposed long sides. One outer surface in the stacking direction of the upper stacked body 7 is bonded to the internal insulating layer 11. An upper insulating layer 17 (first outer insulating layer) is bonded to the other outer surface of the upper stacked body 7 in the stacking direction, that is, the outer surface not facing the inner insulating layer. A first side surface electrode 19 </ b> A and a second side surface electrode 19 </ b> B are provided on one long side surface of the upper stacked body 7.
　５つの電極層１３Ａ～１３Ｅは、いずれも銀とパラジウム金属粉と、ガラスフリットと、樹脂とからなる導電性ペーストを用いて形成されている。 The five electrode layers 13A to 13E are all formed using a conductive paste made of silver, palladium metal powder, glass frit, and resin.
　電極層１３Ａ、１３Ｃ及び１３Ｅは、それぞれ第１の側面電極１９Ａを介して互いに電気的に接続されている。電極層１３Ａ、１３Ｃ及び１３Ｅは、第１の側面電極１９Ａと接触するために、第１の側面電極１９Ａと対向する部分が積層圧電体５の外部に露出するように張り出した張り出し部２１Ａ、２１Ｃ及び２１Ｅをそれぞれ有して、略矩形状に形成されている。電極層１３Ｂ及び１３Ｄは、それぞれ第２の側面電極１９Ｂを介して互いに電気的に接続されている。電極層１３Ｂ及び１３Ｄは、第２の側面電極１９Ｂと接触するために、第２の側面電極と対向する部分が積層圧電体５の外部に露出するように張り出した張り出し部２１Ｂ及び２１Ｄをそれぞれ有して、略矩形状に形成されている。 The electrode layers 13A, 13C, and 13E are electrically connected to each other via the first side electrode 19A. Since the electrode layers 13A, 13C, and 13E are in contact with the first side surface electrode 19A, the overhanging portions 21A, 21C are projected so that portions facing the first side surface electrode 19A are exposed to the outside of the laminated piezoelectric body 5. And 21E, and is formed in a substantially rectangular shape. The electrode layers 13B and 13D are electrically connected to each other via the second side surface electrode 19B. Since the electrode layers 13B and 13D are in contact with the second side surface electrode 19B, the electrode layers 13B and 13D have overhang portions 21B and 21D that protrude so that the portion facing the second side surface electrode is exposed to the outside of the multilayered piezoelectric body 5, respectively. And it is formed in the substantially rectangular shape.
　４つの圧電セラミック層１５Ａ～１５Ｄは、矩形形状に構成されており、電極層１３Ｂ～１３Ｄを挟んで隣り合う圧電セラミック層の分極方向が互いに逆になるように、積層方向に分極処理されている。図１においては、圧電セラミック層１５Ａ～１５Ｄの分極方向がそれぞれ符号Ｐが付された矢印で示されている。 The four piezoelectric ceramic layers 15A to 15D are formed in a rectangular shape, and are polarized in the stacking direction so that the polarization directions of adjacent piezoelectric ceramic layers sandwiching the electrode layers 13B to 13D are opposite to each other. . In FIG. 1, the polarization directions of the piezoelectric ceramic layers 15A to 15D are indicated by arrows with a symbol P, respectively.
　上部絶縁層１７は、圧電セラミック層と同じ材料により、圧電セラミック層と略同一の大きさの板状に構成されて、上部積層体７の積層方向の他方の外面に接合されている。上部絶縁層１７には、上部積層体７が接合される面と対向する面の長手方向の一方の端部に第１の電極部２３Ａが設けられており、他方の端部に第２の電極部２３Ｂが設けられている。本実施の形態では、第１の電極部２３Ａ及び第２の電極部２３Ｂにより、第１の一対の外部電極が構成されている。なお上部絶縁層１７は、分極処理が施されていない。 The upper insulating layer 17 is made of the same material as the piezoelectric ceramic layer and is formed in a plate shape having substantially the same size as the piezoelectric ceramic layer, and is joined to the other outer surface in the stacking direction of the upper stacked body 7. The upper insulating layer 17 is provided with a first electrode portion 23A at one end in the longitudinal direction of the surface facing the surface to which the upper stacked body 7 is bonded, and the second electrode at the other end. A portion 23B is provided. In the present embodiment, the first pair of external electrodes is constituted by the first electrode portion 23A and the second electrode portion 23B. The upper insulating layer 17 is not subjected to polarization treatment.
　第１の電極部２３Ａ及び第２の電極部２３Ｂには、外部の交流電源から電力を上部積層体７に供給するリード線Ｒがそれぞれ接続されている。第１の電極部２３Ａは、第１の側面電極１９Ａと接続するように構成されており、外部の交流電源からリード線Ｒを介して供給された電力を第１の側面電極１９Ａに供給する。本実施の形態においては、第１の電極部２３Ａは、第１の側面電極１９Ａと一体に形成されている。また、第２の電極部２３Ｂは、第２の側面電極１９Ｂと一体に形成されており、外部の交流電源からリード線Ｒを介して供給された電力を第２の側面電極１９Ｂに供給する。 The lead wires R for supplying power from an external AC power source to the upper laminate 7 are connected to the first electrode portion 23A and the second electrode portion 23B, respectively. The first electrode portion 23A is configured to be connected to the first side electrode 19A, and supplies power supplied from the external AC power source via the lead wire R to the first side electrode 19A. In the present embodiment, the first electrode portion 23A is formed integrally with the first side electrode 19A. The second electrode portion 23B is formed integrally with the second side surface electrode 19B, and supplies power supplied from the external AC power source via the lead wire R to the second side surface electrode 19B.
　本実施の形態の下部積層体９は、図１及び図２に示すように、上部積層体７とほぼ同様の構成を有している。すなわち、下部積層体９は、５つの電極層１３Ｆ～１３Ｊと、４つの圧電セラミック層１５Ｅ～１５Ｈが交互に積層されて構成されている。従って本実施の形態の下部積層体９の圧電セラミックス層１５Ｅ～１５Ｈは、それぞれ両面に電極層が配置されている。なお下部積層体９を構成する電極層及び圧電セラミック層の数は、上部積層体７を構成する電極層及び圧電セラミック層の数と同一でなくともよい。下部積層体９の積層方向の一方の外面は、内部絶縁層１１と接合されている。また下部積層体９の積層方向の他方の外面には、下部絶縁層２５（第２の外部絶縁層）が接合されている。下部積層体９には、第３の側面電極１９Ｃ及び第４の側面電極１９Ｄが設けられている。第３の側面電極１９Ｃ及び第４の側面電極１９Ｄは、第１の側面電極１９Ａ及び第２の側面電極１９Ｂが設けられた側面と対向する側の側面に設けられている。なお、第３の側面電極１９Ｃ及び第４の側面電極１９Ｄは、第１の側面電極１９Ａ及び第２の側面電極１９Ｂが設けられた側面と同じ側の側面に設けてもよい。 The lower laminated body 9 of the present embodiment has a configuration substantially similar to that of the upper laminated body 7 as shown in FIGS. That is, the lower laminate 9 is configured by alternately laminating five electrode layers 13F to 13J and four piezoelectric ceramic layers 15E to 15H. Therefore, the piezoelectric ceramic layers 15E to 15H of the lower laminate 9 of the present embodiment have electrode layers disposed on both sides. The number of electrode layers and piezoelectric ceramic layers that constitute the lower laminate 9 may not be the same as the number of electrode layers and piezoelectric ceramic layers that constitute the upper laminate 7. One outer surface in the stacking direction of the lower stacked body 9 is joined to the internal insulating layer 11. A lower insulating layer 25 (second outer insulating layer) is bonded to the other outer surface of the lower stacked body 9 in the stacking direction. The lower laminate 9 is provided with a third side electrode 19C and a fourth side electrode 19D. The third side surface electrode 19C and the fourth side surface electrode 19D are provided on the side surface opposite to the side surface on which the first side surface electrode 19A and the second side surface electrode 19B are provided. The third side electrode 19C and the fourth side electrode 19D may be provided on the same side as the side on which the first side electrode 19A and the second side electrode 19B are provided.
　電極層１３Ｆ、１３Ｈ及び１３Ｊは、それぞれ第３の側面電極１９Ｃを介して互いに電気的に接続されている。電極層１３Ｆ、１３Ｈ及び１３Ｊは、第３の側面電極１９Ｃと接触するために、第３の側面電極１９Ｃと対向する部分が積層圧電体５の外部に露出するように張り出した張り出し部２１Ｆ、２１Ｈ及び２１Ｊをそれぞれ有して、略矩形状に形成されている。電極層１３Ｇ及び１３Ｉは、それぞれ第４の側面電極１９Ｄを介して互いに電気的に接続されている。電極層１３Ｇ及び１３Ｉは、第４の側面電極１９Ｄと接触するために、第４の側面電極１９Ｄと対向する部分が積層圧電体５の外部に露出するように張り出した張り出し部２１Ｇ及び２１Ｉをそれぞれ有して、略矩形状に形成されている。 The electrode layers 13F, 13H, and 13J are electrically connected to each other via the third side surface electrode 19C. Since the electrode layers 13F, 13H, and 13J are in contact with the third side surface electrode 19C, the overhang portions 21F, 21H that protrude so that portions facing the third side surface electrode 19C are exposed to the outside of the multilayer piezoelectric body 5 are exposed. And 21J, respectively, are formed in a substantially rectangular shape. The electrode layers 13G and 13I are electrically connected to each other through the fourth side surface electrode 19D. Since the electrode layers 13G and 13I are in contact with the fourth side surface electrode 19D, the overhanging portions 21G and 21I that protrude so that the portion facing the fourth side surface electrode 19D is exposed to the outside of the multilayer piezoelectric body 5 are respectively provided. And has a substantially rectangular shape.
　４つの圧電セラミック層１５Ｅ～１５Ｈは、矩形形状に構成されており、電極層１３Ｇ～１３Ｉを挟んで隣り合う圧電セラミック層の分極方向が互いに逆になるように、積層方向に分極処理されている。図１においては、圧電セラミック層１５Ｅ～１５Ｈの分極方向がそれぞれ符号Ｐが付された矢印で示されている。本実施の形態においては、圧電セラミック層１５Ｅ～１５Ｈの分極方向は、それぞれ圧電セラミック層１５Ａ～１５Ｄの分極方向と同一となるように分極処理をしてある。 The four piezoelectric ceramic layers 15E to 15H are formed in a rectangular shape, and are polarized in the stacking direction so that the polarization directions of adjacent piezoelectric ceramic layers sandwiching the electrode layers 13G to 13I are opposite to each other. . In FIG. 1, the polarization directions of the piezoelectric ceramic layers 15E to 15H are indicated by arrows with a reference symbol P. In the present embodiment, the polarization processing is performed so that the polarization directions of the piezoelectric ceramic layers 15E to 15H are the same as the polarization directions of the piezoelectric ceramic layers 15A to 15D, respectively.
　下部絶縁層２５は、圧電セラミック層と同じ材料により、圧電セラミック層と略同一の大きさの板状に構成されて、下部積層体９の積層方向の他方の端面に接合されている。下部絶縁層２５には、下部積層体９が接合される面と対向する面の長手方向の一方の端部に第３の電極部２３Ｃが設けられており、他方の端部に第４の電極部２３Ｄが設けられている。第３の電極部２３Ｃ及び第４の電極部２３Ｄは、支持プレート３の図示しない電気回路に接続されており、外部の交流電源から供給された電力を電気回路を介して第３の側面電極１９Ｃ及び第４の側面電極１９Ｄに供給する。本実施の形態では、第３の電極部２３Ｃ及び第４の電極部２３Ｄにより、第２の一対の外部電極が構成されている。なお下部絶縁層２５は、分極処理が施されていない。 The lower insulating layer 25 is made of the same material as the piezoelectric ceramic layer and is formed in a plate shape having substantially the same size as the piezoelectric ceramic layer, and is joined to the other end surface of the lower stacked body 9 in the stacking direction. The lower insulating layer 25 is provided with a third electrode portion 23C at one end in the longitudinal direction of the surface facing the surface to which the lower stacked body 9 is bonded, and the fourth electrode at the other end. A portion 23D is provided. The third electrode portion 23C and the fourth electrode portion 23D are connected to an electric circuit (not shown) of the support plate 3, and power supplied from an external AC power source is supplied to the third side electrode 19C via the electric circuit. And supplied to the fourth side electrode 19D. In the present embodiment, the third electrode portion 23C and the fourth electrode portion 23D constitute a second pair of external electrodes. The lower insulating layer 25 is not subjected to polarization treatment.
　内部絶縁層１１は、３つの圧電セラミック層１１Ａ～１１Ｃを積層して構成されている。本実施の形態の内部絶縁層１１を構成する３つの圧電セラミック層１１Ａ～１１Ｃは、上部積層体７を構成する４つの圧電セラミック層１５Ａ～１５Ｄ及び下部積層体９を構成する４つの圧電セラミック層１５Ｅ～１５Ｈと同じ材料を用いて同じ大きさに形成している。従って本実施の形態の積層圧電体５は、全部で１１層の圧電セラミック層を有している。また、本実施の形態の積層圧電体５は、上部絶縁層１７及び下部絶縁層２５を含めると、全部で１３層の圧電セラミック層を有している。なお３つの圧電セラミック層１１Ａ～１１Ｃは、分極処理が施されていない。 The internal insulating layer 11 is formed by laminating three piezoelectric ceramic layers 11A to 11C. The three piezoelectric ceramic layers 11A to 11C constituting the internal insulating layer 11 of the present embodiment include the four piezoelectric ceramic layers 15A to 15D constituting the upper laminate 7 and the four piezoelectric ceramic layers constituting the lower laminate 9. The same size is used using the same material as 15E-15H. Therefore, the laminated piezoelectric material 5 of the present embodiment has a total of 11 piezoelectric ceramic layers. In addition, the laminated piezoelectric body 5 of the present embodiment includes a total of 13 piezoelectric ceramic layers including the upper insulating layer 17 and the lower insulating layer 25. The three piezoelectric ceramic layers 11A to 11C are not subjected to polarization treatment.
　本実施の形態においては、内部絶縁層１１に隣接して配置される上部積層体７の圧電セラミックス層１５Ｄの分極方向と、下部積層体９の圧電セラミックス層１５Ｅの分極方向とが互いに逆になるように、上部積層体７と下部積層体９とを積層している。そこで、第１の側面電極１９Ａの極性と第３の側面電極１９Ｃの極性が同じとなり、第２の側面電極１９Ｂの極性と第４の側面電極１９Ｄの極性が同じとなるように構成している。そのため、上部積層体７が縮み動作をしているときに下部積層体９が伸び動作をし、上部積層体７が伸び動作をしているときに下部積層体９が縮み動作をする。なお、内部絶縁層１１に隣接して配置される上部積層体７の圧電セラミックス層の分極方向と、下部積層体９の圧電セラミックス層の分極方向とが同じである場合には、駆動時の上部積層体７の振幅モードと下部積層体９の振幅モードを逆にするために、すなわち上部積層体７が縮み動作をしているときに下部積層体９が伸び動作をし、上部積層体７が伸び動作をしているときに下部積層体９が縮み動作をするようにするために、第１の側面電極１９Ａの極性と第４の側面電極１９Ｄの極性が同じとなり、第２の側面電極１９Ｂの極性と第３の側面電極１９Ｃの極性が同じとなるように構成すればよい。また本実施の形態においては、各電極層と絶縁層の電極部とを側面電極を用いて電気的に接続しているが、圧電セラミック層にスルーホールを設けて、スルーホールに電極材料を注入して各電極層と絶縁層の電極部とを電気的に接続してもよい。 In the present embodiment, the polarization direction of the piezoelectric ceramic layer 15D of the upper laminate 7 disposed adjacent to the internal insulating layer 11 and the polarization direction of the piezoelectric ceramic layer 15E of the lower laminate 9 are opposite to each other. Thus, the upper laminated body 7 and the lower laminated body 9 are laminated | stacked. Therefore, the first side surface electrode 19A and the third side surface electrode 19C have the same polarity, and the second side surface electrode 19B and the fourth side surface electrode 19D have the same polarity. . Therefore, the lower stacked body 9 performs an extending operation when the upper stacked body 7 performs a contracting operation, and the lower stacked body 9 performs a contracting operation when the upper stacked body 7 performs an extending operation. When the polarization direction of the piezoelectric ceramic layer of the upper laminate 7 disposed adjacent to the inner insulating layer 11 is the same as the polarization direction of the piezoelectric ceramic layer of the lower laminate 9, the upper portion during driving is used. In order to reverse the amplitude mode of the laminated body 7 and the amplitude mode of the lower laminated body 9, that is, when the upper laminated body 7 is in a contracting operation, the lower laminated body 9 performs an extending operation, and the upper laminated body 7 In order to cause the lower stacked body 9 to perform a contraction operation during the extension operation, the polarity of the first side electrode 19A and the polarity of the fourth side electrode 19D are the same, and the second side electrode 19B And the third side electrode 19C may be configured to have the same polarity. In this embodiment, each electrode layer and the electrode portion of the insulating layer are electrically connected using side electrodes, but through holes are provided in the piezoelectric ceramic layer, and electrode material is injected into the through holes. Then, each electrode layer and the electrode portion of the insulating layer may be electrically connected.
　次に本発明の積層圧電体及び比較例の積層圧電体の静電容量、振幅、周波数特性等の出力特性について行った試験について説明する。試験は、図３に示す４種類の積層圧電体を準備して行った。図３には、試験を行った４種類の積層圧電体の電極層の配置状態を模式的に表した積層圧電体が示されている。なお、図３には、側面電極、上部絶縁層、下部電極層は示されていない。図３（Ａ）及び（Ｂ）は比較例としての積層圧電体である。なお、出力特性の変化を顕著にするために、積層圧電体中に積層される圧電セラミック層の全体の数を１７層として試験を行った。図３（Ａ）の積層圧電体は、１７層の圧電セラミック層の全ての両面に電極層が設けられた従来の積層圧電体である（比較例１）。図３（Ｂ）の積層圧電体は、支持プレート３に隣接する圧電セラミック層から６層分の圧電セラミック層の各層の間に電極層を設けなかった積層圧電体である（比較例２）。図３（Ｃ）及び（Ｄ）は本発明の実施例としての積層圧電体である。図３（Ｃ）の積層圧電体では、上部積層体７及び下部積層体９の圧電セラミック層の数を６層で等しく、内部絶縁層１１の圧電セラミック層の数を５層としている（実施例１）。図３（Ｄ）の積層圧電体では、上部積層体７の圧電セラミック層の数を８層とし、下部積層体９の圧電セラミック層の数を４層とし、内部絶縁層１１の圧電セラミック層の数を５層としている（実施例２）。 Next, tests performed on output characteristics such as capacitance, amplitude, and frequency characteristics of the multilayered piezoelectric body of the present invention and the multilayered piezoelectric body of the comparative example will be described. The test was performed by preparing four types of laminated piezoelectric materials shown in FIG. FIG. 3 shows a multilayer piezoelectric body schematically showing the arrangement state of the electrode layers of the four types of multilayer piezoelectric bodies tested. Note that FIG. 3 does not show the side electrode, the upper insulating layer, and the lower electrode layer. 3A and 3B show a laminated piezoelectric body as a comparative example. In order to make the change in the output characteristics remarkable, the test was performed with the total number of piezoelectric ceramic layers laminated in the laminated piezoelectric body being 17 layers. The laminated piezoelectric material shown in FIG. 3A is a conventional laminated piezoelectric material in which electrode layers are provided on both surfaces of 17 piezoelectric ceramic layers (Comparative Example 1). The laminated piezoelectric material of FIG. 3B is a laminated piezoelectric material in which no electrode layer is provided between the piezoelectric ceramic layers corresponding to six layers from the piezoelectric ceramic layer adjacent to the support plate 3 (Comparative Example 2). FIGS. 3C and 3D show a laminated piezoelectric material as an example of the present invention. In the laminated piezoelectric material of FIG. 3C, the number of piezoelectric ceramic layers of the upper laminated body 7 and the lower laminated body 9 is equal to 6 layers, and the number of piezoelectric ceramic layers of the internal insulating layer 11 is 5 (Example) 1). 3D, the number of the piezoelectric ceramic layers of the upper laminated body 7 is eight, the number of the piezoelectric ceramic layers of the lower laminated body 9 is four, and the piezoelectric ceramic layers of the internal insulating layer 11 are the same. The number is 5 layers (Example 2).
　試験に用いた圧電セラミックスは、チタン酸ジルコン酸鉛からなる圧電セラミックスで、長さ５０ｍｍ、幅６ｍｍ、厚み０．３ｍｍの寸法を有していた。試験は、準備した積層圧電体をそれぞれ長さ５０ｍｍ、幅６ｍｍ、高さ０．５ｍｍの樹脂製の支持プレート３に、幅３ｍｍの両面テープで接合して、行った。この試験では、実効値で８．５Ｖ（８．５Ｖｒｍｓ）の電圧を印加したときの静電容量の目標値を１．７μＦとして行った。 The piezoelectric ceramic used in the test was a piezoelectric ceramic made of lead zirconate titanate, and had dimensions of 50 mm in length, 6 mm in width, and 0.3 mm in thickness. The test was performed by joining the prepared laminated piezoelectric body to a resin support plate 3 having a length of 50 mm, a width of 6 mm, and a height of 0.5 mm, respectively, with a double-sided tape having a width of 3 mm. In this test, the target value of the electrostatic capacity when an effective voltage of 8.5 V (8.5 Vrms) was applied was set to 1.7 μF.
　図４は、比較例１、比較例２、実施例１及び実施例２の試験結果のうち、静電容量測定値、振幅量及び静電容量あたりの振幅量（振幅量／静電容量）をまとめた表である。従来の積層圧電体である比較例１では、静電容量値は２．９１μＦであり、振幅値は７３．８μｍであった。比較例２では、静電容量値は１．８９μＦまで下げることができ、静電容量あたりの振幅値を３４．０７まで大きくすることができている。しかしながら、振幅値も６４．４μｍに下がっており、出力が低くなってしまっている。 FIG. 4 shows the capacitance measurement value, amplitude amount, and amplitude amount per capacitance (amplitude amount / capacitance) among the test results of Comparative Example 1, Comparative Example 2, Example 1 and Example 2. It is a summary table. In Comparative Example 1, which is a conventional multilayer piezoelectric body, the capacitance value was 2.91 μF and the amplitude value was 73.8 μm. In Comparative Example 2, the capacitance value can be lowered to 1.89 μF, and the amplitude value per capacitance can be increased to 34.07. However, the amplitude value has also decreased to 64.4 μm, and the output has become low.
　実施例１の積層圧電体では、静電容量値は１．７５μＦまで下がり、しかも振幅値が７４．１μｍまであがっているので、回路への負担を小さくでき、しかも大きな出力を得ることができている。従って、静電容量あたりの振幅値は４２．３４まで大きくすることができているので、積層圧電体の効率が向上している。また、実施例２の積層圧電体では、静電容量値は１．７８μＦまでしか下がらず、実施例１の静電容量値よりも僅かではあるが大きくなっている。しかしながら、振幅値が７８．８μｍまであがっている。そのため、静電容量あたりの振幅値は４４．２７まで大きくすることができているので、実施例１積層圧電体よりも効率が向上している。 In the laminated piezoelectric material of Example 1, the capacitance value is reduced to 1.75 μF and the amplitude value is increased to 74.1 μm. Therefore, the burden on the circuit can be reduced and a large output can be obtained. Yes. Therefore, the amplitude value per electrostatic capacity can be increased to 42.34, so that the efficiency of the laminated piezoelectric material is improved. Further, in the multilayered piezoelectric body of Example 2, the capacitance value only decreased to 1.78 μF, which is slightly larger than the capacitance value of Example 1. However, the amplitude value is increased to 78.8 μm. Therefore, the amplitude value per electrostatic capacity can be increased to 44.27, so that the efficiency is improved as compared with the multilayer piezoelectric body of Example 1.
　図５（Ａ）は、比較例１、比較例２のインピーダンスと周波数の関係（周波数－インピーダンス特性）を表すグラフであり、図５（Ｂ）は実施例１及び実施例２のインピーダンスと周波数の関係（周波数－インピーダンス特性）を表すグラフである。従来の積層圧電体である比較例１では、１０９０Ｈｚで４３Ωの共振インピーダンスとなる。比較例２の周波数特性は、１１２５Ｈｚで４０Ωの共振インピーダンスとなっている。比較例２では、比較例１に比べて共振インピーダンスが小さくなっているので、積層圧電体を駆動するための電流を大きくしなければならない。そのため、回路にかかる負担が大きくなる。また、共振周波数が大きくなっているため、比較例１に比べてロス（電力損失）が大きくなっていると考えられる。 FIG. 5A is a graph showing the relationship between impedance and frequency (frequency-impedance characteristics) of Comparative Example 1 and Comparative Example 2, and FIG. 5B is a graph showing the impedance and frequency of Example 1 and Example 2. It is a graph showing a relationship (frequency-impedance characteristic). In Comparative Example 1, which is a conventional multilayer piezoelectric body, the resonance impedance is 43Ω at 1090 Hz. The frequency characteristic of Comparative Example 2 has a resonance impedance of 40Ω at 1125 Hz. In Comparative Example 2, since the resonance impedance is smaller than that in Comparative Example 1, the current for driving the laminated piezoelectric material must be increased. As a result, the load on the circuit increases. Further, since the resonance frequency is large, it is considered that the loss (power loss) is larger than that of Comparative Example 1.
　これに対して本発明の実施例１では、１０９０Ｈｚで５６Ωの共振インピーダンスを示す周波数－インピーダンス特性となっている。実施例１の圧電積層体では、共振周波数に変化はないものの、インピーダンスの値が増加している。そのため、回路にかかる負担が小さくなる。また、本発明の実施例２の圧電積層体では、１０４０Ｈｚで５４Ωの共振インピーダンスを示す周波数－インピーダンス特性を示している。実施例２の圧電積層体では、共振周波数が小さくなっているので、従来の積層圧電体である比較例１に比べて、ロス（電力損失）を小さくすることができる。しかも、共振インピーダンスの値も大きくなっているので、回路にかかる負担を小さくすることができている。 On the other hand, in Example 1 of the present invention, the frequency-impedance characteristic showing a resonant impedance of 56Ω at 1090 Hz is obtained. In the piezoelectric laminated body of Example 1, although the resonance frequency does not change, the impedance value is increased. Therefore, the burden on the circuit is reduced. In addition, the piezoelectric laminate of Example 2 of the present invention shows frequency-impedance characteristics showing a resonance impedance of 54Ω at 1040 Hz. In the piezoelectric laminated body of Example 2, since the resonance frequency is low, loss (power loss) can be reduced as compared with Comparative Example 1 which is a conventional laminated piezoelectric body. In addition, since the value of the resonance impedance is also increased, the load on the circuit can be reduced.
　上記実施の形態では各電極層に交流電圧を印加して駆動しているが、本発明は、直流電圧で駆動する積層圧電体にも適用することができるのは勿論である。 In the above embodiment, each electrode layer is driven by applying an AC voltage, but the present invention can also be applied to a laminated piezoelectric body driven by a DC voltage.
　また上記実施の形態では、全部で１１層の圧電セラミック層からなる積層圧電体及び全部で１７層の圧電セラミック層からなる積層圧電体を例として示したが、積層圧電体を構成する圧電セラミック層の数は、これらに限定されない。 In the above-described embodiment, the laminated piezoelectric body composed of a total of 11 piezoelectric ceramic layers and the laminated piezoelectric body composed of a total of 17 piezoelectric ceramic layers are shown as examples. However, the piezoelectric ceramic layers constituting the laminated piezoelectric body are shown as examples. The number of is not limited to these.
　また、上部絶縁層、下部絶縁層、内部絶縁層を、上部積層体及び下部積層体を構成する圧電セラミック層により構成したが、異なる材料で構成してもよいのは勿論である。 Further, although the upper insulating layer, the lower insulating layer, and the inner insulating layer are constituted by the piezoelectric ceramic layers constituting the upper laminated body and the lower laminated body, it is needless to say that they may be constituted by different materials.
　本発明によれば、駆動時の積層圧電体の振動にほとんど寄与しない積層振動体の積層方向の中央部に位置する部分を内部絶縁層により構成し、かつ、駆動時の第１の積層体の振幅モードと第２の積層体の振幅モードが逆になるように、第１の積層体及び第２の積層体を構成している。そのため、振幅を維持したまま静電容量を低下させることができ、静電容量あたりの振幅量を大きくすることができ、積層圧電体の性能を高くすることができる。また積層圧電体中の電極層を減らすことができるので、積層圧電体を安価に製造することができる。さらに見掛け上バイモルフ型の圧電型振動素子と同じように動作するので、従来のユニモルフ型の積層圧電体よりも振幅出力を大きくすることができる。 According to the present invention, the portion located in the central portion in the stacking direction of the multilayer vibrator that hardly contributes to the vibration of the multilayer piezoelectric body at the time of driving is configured by the internal insulating layer, and the first multilayer body at the time of driving is configured. The first stacked body and the second stacked body are configured so that the amplitude mode and the amplitude mode of the second stacked body are reversed. Therefore, the capacitance can be reduced while maintaining the amplitude, the amount of amplitude per capacitance can be increased, and the performance of the laminated piezoelectric body can be improved. In addition, since the electrode layers in the laminated piezoelectric material can be reduced, the laminated piezoelectric material can be manufactured at low cost. Furthermore, since it operates in the same manner as an apparently bimorph type piezoelectric vibration element, the amplitude output can be made larger than that of a conventional unimorph type multilayer piezoelectric body.
　１　圧電型振動素子
　３　支持プレート
　５　積層圧電体
　７　上部積層体
　９　下部積層体
　１１　内部絶縁層
　１１Ａ～１１Ｃ　圧電セラミック層
　１３Ａ～１３Ｊ　電極層
　１５Ａ～１５Ｈ　圧電セラミック層
　１７　上部絶縁層
　１９Ａ～１９Ｄ　側面電極
　２１Ａ～２１Ｊ　張り出し部
　２３Ａ～２３Ｄ　電極部
　２５　下部電極層
　Ｒ　リード線
　Ｐ　分極方向 DESCRIPTION OF SYMBOLS 1 Piezoelectric vibration element 3 Support plate 5 Laminated piezoelectric body 7 Upper laminated body 9 Lower laminated body 11 Internal insulating layer 11A-11C Piezoelectric ceramic layer 13A-13J Electrode layer 15A-15H Piezoelectric ceramic layer 17 Upper insulating layer 19A-19D Side electrode 21A-21J Overhang 23A-23D Electrode 25 Lower electrode layer R Lead wire P Polarization direction

Claims (5)

  1. 　両面に電極層が配置され且つ分極処理が施された複数の圧電セラミック層が積層されてなる第１の積層体と、
    　両面に電極層が配置され且つ分極処理が施された複数の圧電セラミック層が積層されてなる第２の積層体と、
    　前記第１の積層体と前記第２の積層体との間に配置された内部絶縁層とからなり、
    　駆動時の前記第１の積層体の振幅モードと前記第２の積層体の振幅モードが逆になるように、前記第１の積層体の前記複数の圧電セラミックス層及び前記第２の積層体の前記複数の圧電セラミックス層が分極処理されており、
    　前記第２の積層体のみが可撓性のある支持プレートにより支持されており、
    　前記内部絶縁層は、分極処理が施されていない複数の圧電セラミックシートの積層体によって構成されており、
    　前記第１の積層体の前記内部絶縁層と対向しない外面には、第１の一対の外部電極を備えた第１の外部絶縁層が配置され、
    　前記第２の積層体の前記内部絶縁層と対向しない外面には、第２の一対の外部電極を備えた第２の外部絶縁層が配置され、
    　前記第１の外部絶縁層の前記第１の一対の外部電極に交流電圧が印加されたときに、前記第１の積層体及び前記第２の積層体が異なる振幅モードで振動するように、前記第１の一対の外部電極層と、前記第１の積層体中の複数の前記電極層と、前記第２の積層体中の複数の前記電極層と、前記第２の一対の外部電極層とが電気的に接続されており、
    　前記第１の積層体の前記複数の圧電セラミック層の数が、前記第２の積層体の前記複数の圧電セラミック層の数よりも多いことを特徴とする積層圧電体。     A first laminate in which a plurality of piezoelectric ceramic layers having electrode layers disposed on both sides and subjected to polarization treatment are laminated;
    A second laminate in which a plurality of piezoelectric ceramic layers having electrode layers arranged on both sides and subjected to polarization treatment are laminated;
    An internal insulating layer disposed between the first laminate and the second laminate,
    The plurality of piezoelectric ceramic layers and the second laminate of the first laminate so that the amplitude mode of the first laminate and the amplitude mode of the second laminate are reversed during driving. The plurality of piezoelectric ceramic layers are polarized;
    Only the second laminate is supported by a flexible support plate,
    The internal insulating layer is composed of a laminate of a plurality of piezoelectric ceramic sheets that are not subjected to polarization treatment,
    A first external insulating layer having a first pair of external electrodes is disposed on the outer surface of the first laminate that does not face the internal insulating layer,
    A second external insulating layer having a second pair of external electrodes is disposed on the outer surface of the second laminate that does not face the internal insulating layer,
    When the AC voltage is applied to the first pair of external electrodes of the first external insulating layer, the first stacked body and the second stacked body vibrate in different amplitude modes. A first pair of external electrode layers; a plurality of the electrode layers in the first stack; a plurality of the electrode layers in the second stack; and the second pair of external electrode layers; Are electrically connected,
    The multilayer piezoelectric body, wherein the number of the plurality of piezoelectric ceramic layers of the first multilayer body is greater than the number of the plurality of piezoelectric ceramic layers of the second multilayer body.
  2. 　両面に電極層が配置され且つ分極処理が施された複数の圧電セラミック層が積層されてなる第１の積層体と、
    　両面に電極層が配置され且つ分極処理が施された複数の圧電セラミック層が積層されてなる第２の積層体と、
    　前記第１の積層体と前記第２の積層体との間に配置された内部絶縁層とからなり、
    　駆動時の前記第１の積層体の振幅モードと前記第２の積層体の振幅モードが逆になるように、前記第１の積層体の前記複数の圧電セラミックス層及び前記第２の積層体の前記複数の圧電セラミックス層が分極処理されており、
    　前記第２の積層体のみが可撓性のある支持プレートにより支持されており、
    　前記内部絶縁層は、分極処理が施されていない複数の圧電セラミックシートの積層体によって構成されていることを特徴とする積層圧電体。     A first laminate in which a plurality of piezoelectric ceramic layers having electrode layers disposed on both sides and subjected to polarization treatment are laminated;
    A second laminate in which a plurality of piezoelectric ceramic layers having electrode layers arranged on both sides and subjected to polarization treatment are laminated;
    An internal insulating layer disposed between the first laminate and the second laminate,
    The plurality of piezoelectric ceramic layers and the second laminate of the first laminate so that the amplitude mode of the first laminate and the amplitude mode of the second laminate are reversed during driving. The plurality of piezoelectric ceramic layers are polarized;
    Only the second laminate is supported by a flexible support plate,
    The internal insulating layer is constituted by a laminated body of a plurality of piezoelectric ceramic sheets not subjected to polarization treatment.
  3. 　前記第１の積層体の前記内部絶縁層と対向しない外面には、第１の一対の外部電極を備えた第１の外部絶縁層が配置され、
    　前記第２の積層体の前記内部絶縁層と対向しない外面には、第２の一対の外部電極を備えた第２の外部絶縁層が配置され、
    　前記第１の外部絶縁層の前記第１の一対の外部電極に交流電圧が印加されたときに、前記第１の積層体及び前記第２の積層体が異なる振幅モードで振動するように、前記第１の一対の外部電極層と、前記第１の積層体中の複数の前記電極層と、前記第２の積層体中の複数の前記電極層と、前記第２の一対の外部電極層とが電気的に接続されている請求項２に記載の積層圧電体。     A first external insulating layer having a first pair of external electrodes is disposed on the outer surface of the first laminate that does not face the internal insulating layer,
    A second external insulating layer having a second pair of external electrodes is disposed on the outer surface of the second laminate that does not face the internal insulating layer,
    When the AC voltage is applied to the first pair of external electrodes of the first external insulating layer, the first stacked body and the second stacked body vibrate in different amplitude modes. A first pair of external electrode layers; a plurality of the electrode layers in the first stack; a plurality of the electrode layers in the second stack; and the second pair of external electrode layers; The laminated piezoelectric material according to claim 2, wherein are electrically connected.
  4. 　前記第１の積層体の前記複数の圧電セラミック層の数と前記第２の積層体の前記複数の圧電セラミック層の数が等しい請求項２または３に記載の積層圧電体。 4. The multilayer piezoelectric body according to claim 2, wherein the number of the plurality of piezoelectric ceramic layers of the first multilayer body is equal to the number of the plurality of piezoelectric ceramic layers of the second multilayer body.
  5. 　前記第１の積層体の前記複数の圧電セラミック層の数が、前記第２の積層体の前記複数の圧電セラミック層の数よりも多い請求項２または３に記載の積層圧電体。 4. The multilayer piezoelectric body according to claim 2, wherein the number of the plurality of piezoelectric ceramic layers of the first multilayer body is greater than the number of the plurality of piezoelectric ceramic layers of the second multilayer body.
PCT/JP2012/071554 2011-09-01 2012-08-27 Layered piezoelectric element WO2013031715A1 (en)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103686564A (en) * 2013-12-16 2014-03-26 西安康弘新材料科技有限公司 Multi-layer monolithic ceramic bi-crystal type piezoelectric bone conduction vibrator
JP2015133415A (en) * 2014-01-14 2015-07-23 株式会社日本セラテック Piezoelectric element
CN105027581A (en) * 2014-02-27 2015-11-04 京瓷株式会社 Piezoelectric actuator, and piezoelectric vibration device, portable terminal, acoustic generator, acoustic generation device, and electronic device provided therewith
JP2017204506A (en) * 2016-05-09 2017-11-16 株式会社シマノ Piezoelectric element, and method for manufacturing piezoelectric element
CN110098315A (en) * 2018-01-30 2019-08-06 太阳诱电株式会社 Stacked piezoelectric ceramic component and piezoelectric device

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0443684A (en) * 1990-06-11 1992-02-13 Mitsui Petrochem Ind Ltd Laminated bimorph type piezoelectric element
JP2003209302A (en) * 2002-01-15 2003-07-25 Megasera:Kk Piezoelectric actuator and manufacturing method therefor
WO2005024966A1 (en) * 2003-09-04 2005-03-17 Nec Corporation Piezoelectric ceramic element and portable device
JP2009170631A (en) * 2008-01-16 2009-07-30 Panasonic Corp Piezoelectric element and method of manufacturing the same, and piezoelectric application device using the same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0443684A (en) * 1990-06-11 1992-02-13 Mitsui Petrochem Ind Ltd Laminated bimorph type piezoelectric element
JP2003209302A (en) * 2002-01-15 2003-07-25 Megasera:Kk Piezoelectric actuator and manufacturing method therefor
WO2005024966A1 (en) * 2003-09-04 2005-03-17 Nec Corporation Piezoelectric ceramic element and portable device
JP2009170631A (en) * 2008-01-16 2009-07-30 Panasonic Corp Piezoelectric element and method of manufacturing the same, and piezoelectric application device using the same

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103686564A (en) * 2013-12-16 2014-03-26 西安康弘新材料科技有限公司 Multi-layer monolithic ceramic bi-crystal type piezoelectric bone conduction vibrator
JP2015133415A (en) * 2014-01-14 2015-07-23 株式会社日本セラテック Piezoelectric element
CN105027581A (en) * 2014-02-27 2015-11-04 京瓷株式会社 Piezoelectric actuator, and piezoelectric vibration device, portable terminal, acoustic generator, acoustic generation device, and electronic device provided therewith
CN105027581B (en) * 2014-02-27 2018-01-05 京瓷株式会社 Piezo-activator and piezoelectric vibrating device, portable terminal, sound generator, sound generating apparatus, the electronic equipment for possessing it
JP2017204506A (en) * 2016-05-09 2017-11-16 株式会社シマノ Piezoelectric element, and method for manufacturing piezoelectric element
CN110098315A (en) * 2018-01-30 2019-08-06 太阳诱电株式会社 Stacked piezoelectric ceramic component and piezoelectric device
CN110098315B (en) * 2018-01-30 2024-01-02 太阳诱电株式会社 Laminated piezoelectric ceramic component and piezoelectric device

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