JP2011155126A - Piezoelectric laminated component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric laminated component capable of lowering the entire capacitance while suppressing the reduction of the generation force of the displacement of vibrations. <P>SOLUTION: The piezoelectric laminated component 1 includes a piezoelectric laminated body 5 in which a plurality of piezoelectric body layers 2 are laminated, electrodes 3 are formed between the piezoelectric body layers 2 and on one main surface A and the other main surface B, and terminal electrodes 4a, 4b connected to the electrodes 3 are formed respectively at both end parts, and a shim material 6 with both surfaces where the piezoelectric laminated body 5 is stuck on the side of the one main surface A, respectively. For each piezoelectric laminated body 5, the piezoelectric body layer 2a on the side of the one main surface A has a thickness equal to or more than the thickness of two of the other piezoelectric body layers 2b in the piezoelectric laminated component 1. The capacitance can be reduced while suppressing the reduction of the generation force of the displacement of the vibrations. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a piezoelectric laminated component that vibrates by applying an electric field.

  As a conventional piezoelectric multilayer component, for example, in Patent Document 1, the upper and lower electrodes of a multilayer piezoelectric body and the electrodes facing each other are electrically connected by side electrodes disposed at the end of the multilayer piezoelectric body, and the multilayer piezoelectric body is connected. In a piezoelectric exciter having a structure in which is attached to one side or both sides of a shim, a configuration in which a shim member at a portion where a side electrode of a laminated piezoelectric body is located is removed.

  According to the piezoelectric multi-layer component described in Patent Document 1, since it has a structure that avoids the protrusion due to the side electrode in the longitudinal direction of the multi-layer piezoelectric body, when the shim and the piezoelectric body are bonded by thermocompression bonding with an adhesive layer interposed Since the pressure is uniform and there is no distortion force, the adhesive strength between the shim and the piezoelectric body is increased, and cracks and cracks of the piezoelectric body can be prevented.

JP 2007-329431 A

  By the way, since the piezoelectric layer uses a dielectric ceramic material or the like as a material, when a potential difference is generated between electrodes facing each other with the piezoelectric layer interposed therebetween, capacitance is generated between these electrodes. In particular, in the piezoelectric multilayer component having the configuration disclosed in Patent Document 1, in order to obtain a constant generation force of vibration displacement, a plurality of electrodes must be stacked above and below the multilayer piezoelectric layer and between layers. As a result, the overall capacitance increases.

Here, the power consumption of the piezoelectric multilayer component is represented by “power consumption 消費 (capacitance) × (driving voltage of the piezoelectric multilayer component) ² ”. Therefore, when the capacitance increases, the power consumption is proportionally increased. It was a problem that became large.

  On the other hand, the capacitance is expressed by “capacitance = (dielectric constant) × (electrode area) / (electrode interval)”, so that the interval between the upper and lower electrodes of the laminated piezoelectric layer and between the electrodes is increased. It has been found that the capacitance can be reduced by reducing the area of these electrodes. However, simply increasing the distance between the electrodes or reducing the area of the electrodes can reduce the electrostatic capacity, but the generation force of the vibration displacement of the piezoelectric laminated component is also greatly reduced. Accordingly, there has been a problem of how to reduce the capacitance while suppressing the reduction in the generation force of the vibration displacement of the piezoelectric multilayer component.

  The present invention has been made in view of the problems in the conventional technology as described above, and an object of the present invention is to provide a piezoelectric laminated component capable of reducing the capacitance while suppressing the reduction in the generation force of the vibration displacement. Is to provide.

In the piezoelectric laminated component of the present invention, a plurality of piezoelectric layers are laminated, electrodes are formed on the piezoelectric layers, one main surface and the other main surface, and terminal electrodes connected to the electrodes are formed on both ends, respectively. Piezoelectric laminated parts including a piezoelectric laminated body and a shim material on each of which the piezoelectric laminated body is bonded on the one main surface side, each piezoelectric laminated body having the one main surface The piezoelectric layer on the side has a thickness equal to or greater than that of the other two piezoelectric layers.

  In the piezoelectric laminated component of the present invention, in the above configuration, a non-connected electrode that is not electrically connected to the terminal electrode is formed in the piezoelectric layer on the one main surface side of the piezoelectric laminated body. It is characterized by being.

  The piezoelectric multilayer component of the present invention is characterized in that, in the above configuration, the non-connecting electrodes are not exposed at end surfaces of the both end portions of the piezoelectric multilayer body.

  Further, in the piezoelectric multilayer component according to the present invention, in the above configuration, an end portion of the non-connecting electrode is exposed to one of end surfaces of the both end portions of the piezoelectric multilayer body, and the terminal electrode is not connected to the non-connected electrode. The end portions of the piezoelectric laminate are not connected to the end portions of the electrodes, and are connected to the electrodes disposed on the other main surface side of the piezoelectric laminate body than the non-connected electrodes, respectively. It is characterized by being formed.

  The piezoelectric multilayer component of the present invention is characterized in that, in each of the above-described configurations, an insulating ceramic layer is laminated instead of the piezoelectric layer on the one main surface side of the piezoelectric laminate.

  According to the piezoelectric laminated component of the present invention, each piezoelectric laminated body bonded to the shim material on the one main surface side has a piezoelectric layer on one main surface side having a thickness equal to or more than two other piezoelectric layers. Therefore, the distance between the two electrodes facing each other across the piezoelectric layer on the one main surface side is larger than that of the piezoelectric multilayer component having the conventional configuration. Therefore, since the electrostatic capacitance generated in the piezoelectric layer on the one main surface side can be reduced, the electrostatic capacitance of the entire piezoelectric multilayer component can be reduced.

  In addition, because the piezoelectric layer of the portion that does not contribute much to the generation force of the vibration displacement of the entire piezoelectric multilayer component is thickened by being affixed to the shim material, the thickness of the piezoelectric layer is increased. Reduction of the generation force of vibration displacement can be suppressed.

  As a result, it is possible to provide a piezoelectric multilayer component that can suppress a reduction in the generation force of vibration displacement and at the same time reduce the overall capacitance.

  According to the piezoelectric laminated component of the present invention, when the non-connected electrode that is not electrically connected to the terminal electrode is formed in the piezoelectric layer on the one principal surface side of the piezoelectric laminate, the one principal surface In each of the piezoelectric layer on the side and the other piezoelectric layers, the difference in thermal shrinkage between the two piezoelectric layers caused by the difference in the distance between the electrodes in the stacking direction can be reduced. As a result, compared to the case where no electrode is present in the piezoelectric layer on the one main surface side, the piezoelectric laminate has a difference in thermal shrinkage between the two piezoelectric layers in the piezoelectric laminate during sintering. Warpage can be reduced.

  Further, according to the piezoelectric laminated component of the present invention, when the non-connecting electrodes are not exposed at the end faces of the both ends of the piezoelectric laminate, when forming the terminal electrodes at the both ends of the piezoelectric laminate, for example, dip Even when a conductive paste that becomes a terminal electrode is uniformly applied to the entire area of each of both ends by employing a method or the like, the terminal electrode and the non-connecting electrode can be electrically disconnected. Therefore, since the terminal electrode can be easily formed, it is possible to improve the production efficiency of the piezoelectric laminated component.

Further, according to the piezoelectric laminated component of the present invention, the end of the non-connecting electrode is exposed on one of the end faces of both ends of the piezoelectric laminate, and the terminal electrode is connected to the end of the non-connecting electrode. When the piezoelectric multilayer component is formed, it is partially formed at both ends of the piezoelectric laminate so that it is connected to the electrode disposed on the other main surface side of the piezoelectric laminate relative to the non-connected electrode. When alternately laminating the piezoelectric layers and the electrodes, the configuration of the electrode and the non-connected electrode in each of the piezoelectric layer on one main surface side and the other piezoelectric layers is the end portion of the piezoelectric laminate. It is possible to uniformly align with a configuration in which it is exposed to either one of the end faces. Therefore, since it is not necessary to change the way of forming the electrodes in each of the piezoelectric layer on the one main surface side and the other piezoelectric layers, it is possible to improve the production efficiency of the piezoelectric laminated component.

  Further, according to the piezoelectric laminated component of the present invention, when an insulating ceramic layer is laminated instead of the piezoelectric layer on the one main surface side of the piezoelectric laminated body, the electrode formed on the one principal surface of the piezoelectric laminated body Since insulation with the electrodes formed between the layers of the piezoelectric laminate can be ensured, a highly reliable piezoelectric laminate component can be provided.

(A) is a side view which shows the example of embodiment of the piezoelectric laminated component of this invention, (b) is a top view which shows the example of embodiment of the piezoelectric laminated component of this invention. It is sectional drawing in the XX of an example of embodiment of the piezoelectric laminated component shown in FIG.1 (b). The vertical axis represents the generation force of the vibration displacement of the piezoelectric laminated component, and the horizontal axis represents the frequency of the input signal. The vertical axis represents the generation force of the vibration displacement of the piezoelectric laminated component, and the horizontal axis represents the frequency of the input signal. The vertical axis represents the generation force of the vibration displacement of the piezoelectric laminated component, and the horizontal axis represents the frequency of the input signal. It is sectional drawing in the XX of another example of embodiment of the piezoelectric laminated component shown in FIG.1 (b). It is sectional drawing in the XX of another example of embodiment of the piezoelectric laminated component shown in FIG.1 (b).

  Hereinafter, embodiments of the piezoelectric component according to the present invention will be described in detail with reference to the drawings. It is an external perspective view.

  FIG. 1A is a side view showing an example of the embodiment of the piezoelectric laminated component of the present invention, and FIG. 1B is a top view showing an example of the embodiment of the piezoelectric laminated component of the present invention. FIG. 2 is a sectional view taken along line XX of an example of the embodiment of the piezoelectric laminated component shown in FIG.

  The piezoelectric laminated component 1 of the example shown in FIGS. 1 and 2 is formed by laminating a plurality of piezoelectric layers 2 and forming electrodes 3 between the piezoelectric layers 2 and on one main surface A and the other main surface B. Piezoelectric laminate 5 including terminal electrodes 4a and 4b connected to electrode 3 on each other, and shim material 6 having a piezoelectric laminate 5 attached to both surfaces on one main surface A side on each side. Each of the piezoelectric laminates 5 in the component 1 has a piezoelectric layer 2a on one main surface A side having a thickness equal to or more than two layers of the other piezoelectric layers 2b.

  Of the two main surfaces of the piezoelectric laminate 5, as shown in FIGS. 1 and 2, A on the shim material 6 side is one main surface, and B on the opposite side is the other main surface. Of the plurality of piezoelectric layers 2, 2 a closest to the shim material 6 is a piezoelectric layer on one main surface A side, and 2 b is another piezoelectric layer.

  In the following description, the end of the piezoelectric laminate 5 refers to a portion of the piezoelectric laminate 5 that includes the portion where the terminal electrodes 4a and 4b are formed and the vicinity thereof.

  Moreover, in the following description, the end surface of the piezoelectric laminate 5 is a surface including an exposed portion of the electrode 3 from the piezoelectric laminate and a connection portion between the terminal electrodes 4a and 4b among the end portions of the piezoelectric laminate 5. It shows that. In other words, this indicates the surface surrounded by the sides in the thickness direction and the width direction of the piezoelectric laminate 5 among all six surfaces of the piezoelectric laminate 5 having a rectangular parallelepiped shape.

The piezoelectric layer 2, lead zirconate titanate (PZT), lead titanate (PT), sodium-potassium niobate _{(Na 1-x K x NbO} 3), bismuth layered compound _(Example: MBi ₄ Ti _{4 O 15} , M: a divalent alkaline earth metal element) or the like, or a piezoelectric single crystal such as quartz or lithium tantalate.

  From the viewpoint of miniaturization and mountability, the piezoelectric layer 2 is preferably a sheet having a length of 15 to 35 mm, a width of 3.0 to 5.5 mm, and a thickness of 20 to 40 μm.

  The relative dielectric constant of the piezoelectric layer 2 is about 3000 to 4000.

  The piezoelectric laminate 5 is a terminal electrode in which a plurality of piezoelectric layers 2 are laminated, electrodes 3 are formed between the piezoelectric layers 2, one main surface A and the other main surface B, and are connected to the electrodes 3 at both ends. 4a and 4b are respectively formed.

  As shown in FIG. 2, in each piezoelectric laminate 5, the piezoelectric layer 2a on the one main surface A side has a thickness equal to or more than two layers of the other piezoelectric layers 2b. Specifically, the thickness of the piezoelectric layer 2a on the one main surface A side is preferably about 60 μm, and the thickness of the other piezoelectric layer 2b is preferably about 30 μm.

  The thickness of all the piezoelectric layers 2 is about 20 to 60 μm.

  Below, the manufacturing method of the piezoelectric laminated body 5 is demonstrated.

  When the piezoelectric layer 2 is made of, for example, a ceramic material, a method in which a binder is added to the raw material powder and pressed, or the raw material powder is mixed with water and a dispersing agent using a ball mill and then dried to obtain a binder, a solvent, a plasticizer, etc. To form a sheet by a doctor blade method or the like. The silver paste etc. are apply | coated on the sheet | seat of a ceramic material by printing the silver paste etc. which become the electrode 3 to this. About 10 to 15 layers of ceramic material sheets on which such silver paste or the like is printed are laminated to form a laminate.

  Next, this laminate is cut into individual pieces, and then fired at a peak temperature of 1000 to 1100 ° C. for about 24 hours. Terminal electrodes 4a and 4b are formed on both end faces of the fired body to ensure electrical connection between the piezoelectric layers 2 and the electrodes 3 on the one main surface A and the other main surface B.

  The fired body having the terminal electrodes 4a and 4b formed on both end faces is subjected to polarization treatment by applying an electric field of about 3 kV / mm in the thickness direction at room temperature to thereby obtain a piezoelectric laminate 5 having desired piezoelectric characteristics. Is obtained.

  When the piezoelectric layer 2 is made of a piezoelectric single crystal material, desired piezoelectric characteristics are obtained by cutting an ingot (base material) of the piezoelectric single crystal material to be the piezoelectric layer 2 in a predetermined crystal direction. Thus, the piezoelectric layer 2 having the following can be obtained.

  In the method for manufacturing the piezoelectric laminate 5 described above, about 10 to 15 layers of ceramic material sheets printed with a silver paste or the like are laminated to form a laminate, but the piezoelectric layer 2a on the main surface A side is provided. Is formed as follows in order to make the thickness thicker than the other piezoelectric layer 2b.

  For example, the piezoelectric layer 2a may be formed by laminating a plurality of the same ceramic material sheets as the other piezoelectric layers 2b and sintering them. Alternatively, the piezoelectric layer 2a may be formed using a ceramic material sheet that is already thicker than the other ceramic material sheet 2b at the time of the ceramic material sheet before sintering.

  The electrodes 3 of the piezoelectric laminate 5 are formed between the piezoelectric layers 2 of the piezoelectric laminate 5, one main surface A and the other main surface B, and are connected to the terminal electrodes 4 a and 4 b at both ends of the piezoelectric laminate 5. Each is connected. The electrodes 3 are formed to face each other with the piezoelectric layer 2 interposed therebetween.

  The electrode 3 is preferably made of a metal film such as gold, silver, copper, or aluminum from the viewpoint of conductivity.

  The electrode 3 is formed, for example, by baking a conductive paste containing a metal filler such as gold, silver or copper and using low temperature glass as a binder at a predetermined temperature. The thickness of the electrode 3 in this case is such that the electrode 3 formed on the one main surface A and the other main surface B of the piezoelectric laminate 5 is in the range of about 3 to 5 μm, and the electrode 3 formed between the piezoelectric layers 2 is It is preferable to set it as the range of about 1-2 micrometers.

  From the viewpoint of preventing short circuit between the electrodes 3 due to migration and ensuring insulation between the electrode 3 and an external electronic component, both sides of the electrode 3 in the length direction of the electrode 3 are piezoelectric laminated layers. It is preferably formed so as not to be exposed from the side surface of the body 5. Specifically, both side portions of the electrode 3 in the length direction are formed only in a region that recedes from the side surface of the piezoelectric laminate 5 to the inside of the piezoelectric laminate 5.

  The dimensions of the electrode 3 are, for example, when the dimension of the piezoelectric layer 2 is a sheet shape having a length of 30 mm, a width of 5 mm, and a thickness of 30 μm, the dimension in the length direction of the piezoelectric layer 2 is 29.5 mm. The dimension of the piezoelectric layer 2 in the width direction is 4.5 mm, and the thickness is 1 μm.

  The terminal electrodes 4 a and 4 b of the piezoelectric laminate 5 are formed on both ends of the piezoelectric laminate 5. As shown in FIG. 1, the terminal electrodes 4 a and 4 b are formed on the end surfaces of the piezoelectric laminate 5 at both ends of the piezoelectric laminate 5. Further, these terminal electrodes 4 a and 4 b may be formed over one main surface A, the other main surface B, and both side surfaces at both ends of the piezoelectric laminate 5.

  These terminal electrodes 4a and 4b are formed by printing a paste made of silver powder and a binder resin on a ceramic body with a film thickness of 10 to 50 μm and baking at a predetermined temperature condition, for example, a temperature of 600 ° C. to 700 ° C.

  The shim material 6 is a plate-like member in which the piezoelectric laminate 5 is bonded to both main surfaces on the one main surface A side. The material of the shim material 6 is, for example, a nickel alloy such as 42 alloy or other metals.

  A detailed configuration of the bonding of the piezoelectric laminate 5 and the shim material 6 and the power feeding path between them will be described below with reference to FIG.

  An insulating adhesive 8 made of an epoxy resin or an acrylic resin is applied to the entire one main surface A of the piezoelectric laminate 5 so as to cover the electrode 3 formed on the one main surface A. Piezoelectric laminates 5 are bonded to both main surfaces of shim material 6 with insulating adhesive 8 interposed therebetween. Affixing of the piezoelectric laminate 5 to the main surface of the shim material 6 via the insulating adhesive 8 is performed, for example, by applying pressure at room temperature for about 2 minutes. The terminal electrode 4a at one end of the piezoelectric laminate 5 and the main surface of the shim 6 are electrically connected by a conductive resin 9 made of a conductive paste such as silver palladium. On the other hand, the terminal electrode 4b at the other end of the piezoelectric laminate 5 and the main surface of the shim material 6 are electrically insulative because the insulating resin 8 is interposed between them. It is kept. Therefore, different potentials are not short-circuited when a predetermined voltage is applied between the shim 6 and the terminal electrode 4b.

  In the configuration described above, an example in which the electrical connection between the terminal electrode 4a at one end of the piezoelectric laminate 5 and the shim material 6 is secured by the conductive resin 9 is shown in FIG. If both are electrically connected, an insulating resin layer is formed in advance on one main surface A of the piezoelectric laminate 5, and the one main surface A of the piezoelectric laminate 5 on which the insulating resin layer is formed The conductive resin 9 described above may also be used for bonding to the main surface of the shim material 6. That is, the conductive resin 9 serves not only to bond the one main surface A of the piezoelectric laminate 5 and the shim material 6 but also to electrically connect the terminal electrode 4 a and the shim material 6 by one end of the conductive resin 9. It is good also as a structure which serves as both. According to this configuration, the bonding of the piezoelectric laminate 5 and the shim material 6 and the electrical connection of the terminal electrode 4a and the shim material 6 can be performed at the same time, so that the manufacturing cost can be reduced and the manufacturing can be performed. Time can be shortened.

  Even if the terminal electrode 4b formed at the other end of the piezoelectric laminate 5 is formed from the end face of the piezoelectric laminate 5 to the one main surface A, the insulating adhesive 8 described above is used. If the terminal electrode 4b is formed so as to cover the portion extending to the one main surface A, the insulation between the terminal electrode 4b and the shim material 6 can be ensured.

  The dimensions of the shim material 6 are preferably strips having a length of 20 to 40 mm, a width of 3.5 to 5.5 mm, and a thickness of 0.2 to 0.35 mm, for example.

  In the following, the operation of the piezoelectric laminated component 1 including the shim material 6 in which the piezoelectric laminated body 5 is bonded to both principal surfaces on the one principal surface A side will be described.

  In the piezoelectric laminated component 1 of the example shown in FIG. 1, when a fluctuation voltage having a predetermined cycle is applied to the terminal electrodes 4 a and 4 b of the upper piezoelectric laminated body 5 and the lower piezoelectric laminated body 5 of the shim material 6. The expansion and contraction are alternately repeated in the longitudinal direction of the piezoelectric laminate 5 by the piezoelectric effect.

  The piezoelectric laminated bodies 5 of the piezoelectric laminated component 1 of this example are set so that the expansion and contraction phases are opposite to each other. Thereby, in the upper and lower main surfaces of the shim material 6, the force for extending the one main surface A and contracting the other main surface B and the force for extending the other main surface B and contracting the one main surface A are always alternately. Therefore, when one of the shim members 6 is a fixed end, the entire piezoelectric laminated component 1 vibrates in the stacking direction (vertical direction) with the other end of the shim member 6 as a free end. The magnitude of this vibration force is called the generation force of the vibration displacement.

  The generation force of the vibration displacement depends on the expansion and contraction of the piezoelectric laminate 5 and the mass of the piezoelectric laminate 5.

As in the conventional example, in a piezoelectric laminated component in which a plurality of electrodes connected to the terminal electrode are formed on the upper and lower sides and between layers (including the main surface side) of the piezoelectric laminated body, a constant generation force of vibration displacement However, there is a problem that the overall capacitance increases and power consumption increases. Therefore, it has been a problem to reduce the overall capacitance while suppressing the reduction in the generation force of the vibration displacement.

  On the other hand, according to the piezoelectric laminated component 1 of the present invention, each piezoelectric laminated body 5 has a piezoelectric layer 2a on one main surface A side having a thickness equal to or more than two layers of the other piezoelectric layers 2b. Therefore, the distance between the two electrodes 3 facing each other across the piezoelectric layer 2a on the one main surface A side is larger than that of the piezoelectric multilayer component having the conventional configuration. Therefore, since the electrostatic capacitance generated in the piezoelectric layer 2a on the one main surface A side can be reduced, the electrostatic capacitance of the entire piezoelectric laminated component 1 can be reduced.

  Further, since the piezoelectric layer of the portion that does not contribute much to the generation force of the vibration displacement of the entire piezoelectric laminated component 1 is thickened by being attached to the shim material 6 and fixed, the piezoelectric layer is made thicker. Accordingly, it is possible to suppress a reduction in generation force of vibration displacement.

  As a result, it is possible to provide the piezoelectric multilayer component 1 that can suppress a reduction in the generation force of vibration displacement and at the same time reduce the overall capacitance.

  For example, when the piezoelectric laminated component 1 of the present invention is used in a portable electronic device, the overall capacitance of the electronic circuit of the portable electronic device can be reduced while suppressing a reduction in the generation of vibration displacement. Therefore, power consumption of the portable electronic device can be reduced. Therefore, it is possible to make the battery of the portable electronic device last longer.

  Below, the proof by experimental data is shown about the effect that the whole electrostatic capacitance can be lowered | hung while suppressing the reduction of the generation force of the displacement of the vibration by the piezoelectric laminated component 1 of this invention.

  In the experiment conducted for obtaining data, the piezoelectric laminated component 1 shown in FIG. 1 was produced.

  First, in Experimental Example 1, a piezoelectric multilayer component 1 having a configuration in which the thickness of the piezoelectric layer 2a on the one main surface A side of the piezoelectric multilayer body 5 is twice the thickness of the other piezoelectric layer 2b was produced and experimented. Was done.

The dimensions of the piezoelectric laminate 5 were a rectangular parallelepiped shape having a length of 19 mm, a width of 3.5 mm, and a thickness of 0.434 mm. On the other hand, the dimensions of the piezoelectric layer 2a on the main surface A side are 19 mm in length, 3.5 mm in width, and 60 μm in thickness.
m. Other dimensions of the piezoelectric layer 2b are 19mm in length, 3.5mm in width, and 30μm in thickness.
It was. The other piezoelectric layers 2b are 12 layers. As a result, 12 layers of electrodes 3 were formed in the piezoelectric laminate 5. The electrodes 3 were formed on the one main surface A and the other main surface B of the piezoelectric laminate 5 one by one. The dimensions of the electrodes 3 were such that the length in the length direction of the piezoelectric layer 2 was 18.5 mm, the size in the width direction of the piezoelectric layer 2 was 3 mm, and the thickness was 1 μm.

  The terminal electrodes 4a and 4b have a thickness of 20 μm, and the dimensions of the shim material 6 made of a nickel alloy have a strip shape with a length of 25 mm, a width of 4 mm, and a thickness of 0.2 mm.

  The piezoelectric layer 2 was made of lead zirconate titanate (PZT) and had a relative dielectric constant of 3500.

Next, as Comparative Example 1, a piezoelectric laminated component in which the thickness of the piezoelectric layer on one main surface side of the piezoelectric laminate was the same as the thickness of the other piezoelectric layers was produced. The piezoelectric laminated body of this piezoelectric laminated part was formed by laminating 13 piezoelectric layers, and 12 electrodes were laminated in the piezoelectric laminated body. The thickness of the piezoelectric laminate was 0.404 mm. Other configurations, dimensions, and the like were the same as those in Experimental Example 1 of the piezoelectric laminated component 1 of the present invention.

  The values of the electrostatic capacitance and the generation force of the vibration displacement of the piezoelectric laminated component 1 of Experimental Example 1 of the present invention and the piezoelectric laminated component of Comparative Example 1 were measured as follows.

In measuring the capacitance value, an LCR meter (product name: KC-594B, manufactured by Kokuyo Denki Kogyo Co., Ltd.) was used. The signal frequency was measured at 1 kHz. As a result of the measurement, the capacitance value of the piezoelectric laminated component 1 of Experimental Example 1 was 720 pF. In contrast, the capacitance value of the piezoelectric laminated component of Comparative Example 1 was 780 pF.

Moreover, when measuring the generation force of the vibration displacement, a vibration measuring device (manufactured by Bruel & Kjaer, product name: Type 2636) was adopted by the blocked force method. The frequency is 100Hz
Measurement was performed using a sine wave input signal of ˜10 kHz and a voltage of 1V.

  The results of this measurement are shown graphically in FIG. FIG. 3 is a graph in which the vertical axis indicates the generation force (unit: dBN) of vibration displacement of the piezoelectric multilayer component, and the horizontal axis indicates the frequency (unit: Hz) of the input signal. The solid line indicates the measurement result of the piezoelectric multilayer component 1 of Experimental Example 1, the broken line indicates the measurement result of the piezoelectric multilayer component of Comparative Example 1, and the alternate long and short dash line indicates the frequency of the signal applied to the piezoelectric multilayer component. A point at 750 Hz is shown.

Here, the generation force of the vibration displacement when the frequency of the signal input to each piezoelectric multilayer component was 750 Hz was compared and examined. In addition, the reason why the vibration displacement generation force when a signal having a frequency of 750 Hz is input between the piezoelectric laminated component 1 of Experimental Example 1 and the piezoelectric laminated component of Comparative Example 1 is mainly determined by each piezoelectric laminated component. This is because it was produced for the purpose of being used in a portable electronic device to which a high frequency signal around 750 Hz is input.

From the results shown in FIG. 3, in both of these measurement results, the generation force of the vibration displacement of the piezoelectric laminated component 1 of Experimental Example 1 at a frequency of 750 Hz is −20.1 dBN, and the vibration of the piezoelectric laminated component of Comparative Example 1 at a frequency of 750 Hz. The generation force of the displacement was -21.1 dBN.

Therefore, in the piezoelectric laminated component 1 of Experimental Example 1, the generation force of the vibration displacement is changed only within the error range as compared with the piezoelectric laminated component of Comparative Example 1, but the capacitance value is 7.7%. It was possible to reduce.

  Therefore, according to the piezoelectric laminated component 1 of this invention, it turned out that the value of an electrostatic capacitance can be reduced significantly, suppressing the reduction | decrease of the generation force of the displacement of a vibration.

  Next, as Experimental Example 2 of the present invention, the piezoelectric multilayer component 1 having a configuration in which the thickness of the piezoelectric layer 2a on the one main surface A side is three times the thickness of the other piezoelectric layer 2b is manufactured and tested. I did it.

That is, the thickness of the piezoelectric layer 2a on the one main surface A side was 90 μm, and the thickness of the other piezoelectric layer 2b was 30 μm. The other piezoelectric layers 2b are 11 layers. As a result, eleven layers of electrodes 3 were formed in the piezoelectric laminate 5. The thickness of the piezoelectric laminate was 0.433 mm. Other configurations, dimensions, and the like are the same as those of the piezoelectric laminated component 1 of the experimental example 1 having a configuration in which the thickness of the piezoelectric layer 2a is twice the thickness of the piezoelectric layer 2b. A laminated part 1 was produced.

Next, as Comparative Example 2, a piezoelectric laminated component in which the thickness of the piezoelectric layer on one main surface side of the piezoelectric laminate was the same as the thickness of the other piezoelectric layers was produced. The piezoelectric laminated body of this piezoelectric laminated component is such that 12 piezoelectric layers are laminated, and 11 electrodes are laminated in the piezoelectric laminated body. The thickness of the piezoelectric laminate was 0.373 mm. Other configurations, dimensions, and the like were the same as in Experimental Example 2 of the piezoelectric laminated component 1 of the present invention.

  The capacitance value and the force value of the vibration displacement of the piezoelectric laminated component 1 of Experimental Example 2 and the piezoelectric laminated component of Comparative Example 2 were measured by the same measurement method as described above.

As a result of the measurement, the capacitance value of the piezoelectric laminated component 1 of Experimental Example 2 was 660 pF. On the other hand, the capacitance value of the piezoelectric laminated component of Comparative Example 2 was 780 pF.

  Moreover, the measurement result of the generation force of the vibration displacement is shown in a graph in FIG. FIG. 4 is a graph similar to FIG. 3 in which the vertical axis indicates the generation force of the vibration displacement of the piezoelectric multilayer component and the horizontal axis indicates the frequency of the input signal. The solid line indicates the measurement result of the piezoelectric multilayer component 1 of Experimental Example 2, the broken line indicates the measurement result of the piezoelectric multilayer component of Comparative Example 2, and the one-dot chain line indicates that the frequency of the signal applied to the piezoelectric multilayer component is 750 Hz. It shows a certain point.

In these measurement results, when the generation force of vibration displacement at a frequency of 750 Hz is compared, the generation force of vibration displacement of the piezoelectric laminated component 1 of Experimental Example 2 is −20.6 dBN, and the vibration of the piezoelectric laminated component of Comparative Example 2 is The generation force of the displacement was -21.1 dBN.

  Therefore, in the piezoelectric laminated component 1 of Experimental Example 2, the generation force of the vibration displacement is changed only within the error range as compared with the piezoelectric laminated component of Comparative Example 2, but the capacitance value is 15.4%. It was possible to reduce.

  Therefore, according to the piezoelectric laminated component 1 of this invention, it turned out that the value of an electrostatic capacitance can be reduced significantly, suppressing the reduction | decrease of the generation force of the displacement of a vibration.

  Next, as Experimental Example 3 of the present invention, the piezoelectric multilayer component 1 having a configuration in which the thickness of the piezoelectric layer 2a on the one main surface A side is four times the thickness of the other piezoelectric layer 2b is manufactured and tested. I did it.

That is, the thickness of the piezoelectric layer 2a on the one main surface A side is 120 μm, and the other piezoelectric layers 2b
The thickness of the was 30 μm. Further, the other piezoelectric layers 2b are assumed to be laminated. As a result, 10 layers of electrodes 3 were formed in the piezoelectric laminate 5. The thickness of the piezoelectric laminate was 0.432 mm. Other configurations, dimensions, and the like are the same as those of the piezoelectric laminated component 1 of Experimental Example 1 having the configuration in which the thickness of the piezoelectric layer 2a is twice the thickness of the piezoelectric layer 2b. A laminated part 1 was produced.

Next, as Comparative Example 3, a piezoelectric laminated component in which the thickness of the piezoelectric layer on one main surface side of the piezoelectric laminate was the same as the thickness of the other piezoelectric layers was produced. The piezoelectric laminated body of this piezoelectric laminated part has 11 piezoelectric layers laminated, and 10 layers of electrodes are laminated in the piezoelectric laminated body. The thickness of the piezoelectric laminate was 0.342 mm. Other configurations, dimensions, and the like were the same as in Experimental Example 3 of the piezoelectric laminated component 1 of the present invention.

  The capacitance value and the force value of the vibration displacement of the piezoelectric laminated component 1 of Experimental Example 3 and the piezoelectric laminated component of Comparative Example 3 were measured by the same measuring method as described above.

As a result of the measurement, the capacitance value of the piezoelectric multilayer component 1 of Experimental Example 3 was 600 pF. On the other hand, the capacitance value of the piezoelectric laminated component of Comparative Example 3 was 780 pF.

  Moreover, the measurement result of the generation force of the vibration displacement is shown in a graph in FIG. FIG. 5 is a graph similar to FIG. 3 in which the vertical axis indicates the generation force of the vibration displacement of the piezoelectric multilayer component and the horizontal axis indicates the frequency of the input signal. The solid line indicates the measurement result of the piezoelectric multilayer component 1 of Experimental Example 3, the broken line indicates the measurement result of the piezoelectric multilayer component of Comparative Example 3, and the one-dot chain line indicates that the frequency of the signal applied to the piezoelectric multilayer component is 750 Hz. It shows a certain point.

In these measurement results, when the generation force of vibration displacement at a frequency of 750 Hz is compared, the generation force of vibration displacement of the piezoelectric laminated component 1 of Experimental Example 3 is −21.6 dBN, and the vibration of the piezoelectric laminated component of Comparative Example 3 is vibration. The generation force of the displacement was -21.1 dBN.

  Therefore, in the piezoelectric laminated component 1 of Experimental Example 3, the generation force of the vibration displacement changes only within the error range, but the capacitance value is 23.1% compared with the piezoelectric laminated component of Comparative Example 3. It was possible to reduce.

  Therefore, according to the piezoelectric laminated component 1 of this invention, it turned out that the value of an electrostatic capacitance can be reduced significantly, suppressing the reduction | decrease of the generation force of the displacement of a vibration.

  According to the piezoelectric laminated component 1 of the present invention, the non-connected electrode 7 that is not electrically connected to the terminal electrodes 4 a and 4 b is formed in the piezoelectric layer 2 a on the one main surface A side of the piezoelectric laminated body 5. Difference in thermal contraction rate between the two piezoelectric layers 2a and 2b caused by the difference in the distance between the electrodes 3 in the stacking direction in each of the piezoelectric layer 2a on the one main surface A side and the other piezoelectric layer 2b. Can be reduced. As a result, compared to the case where no electrode is present in the piezoelectric layer 2a on the one main surface A side, the difference in thermal contraction between the piezoelectric layers 2a and 2b in the piezoelectric laminate 5 during sintering is caused. Therefore, it is possible to reduce the warp of the piezoelectric laminate 5 to be performed.

  The material of the non-connecting electrode 7 is preferably made of a metal film such as gold, silver, copper, or aluminum, like the electrode 3. By making the material of the non-connecting electrode 7 the same as the material of the electrode 3, the thermal contraction rate of the piezoelectric layer 2 a on the one main surface A side including the non-connecting electrode 7 is the same as that of the other piezoelectric layers 2 b including the electrode 3. This is preferable because it approaches the value of the thermal contraction rate and the difference in thermal contraction rate between the piezoelectric layers 2a and 2b can be reduced.

  The thickness of the non-connection electrode 7 is, for example, about 1 μm. This thickness is preferably set to the same thickness as that of the electrode 3 in that the difference in thermal contraction rate between the piezoelectric layers 2a and 2b can be reduced.

  Further, the distance between the end portion of the non-connecting electrode 7 and the end surfaces of both end portions of the piezoelectric laminate 5 is about 0.5 to 0.6 mm to ensure insulation between the non-connecting electrode 7 and the terminal electrodes 4a and 4b. This is preferable.

  Also, the distance between the non-connecting electrode 7 having a configuration in which the distance from one end face of the piezoelectric laminate 5 is smaller than the distance from the other end face and the distance from the one end face of the piezoelectric laminate 5 is greater than the distance from the other end face. When the non-connecting electrodes 7 having a larger configuration are alternately formed in the piezoelectric layer 2a on the one main surface A side, the difference in thermal contraction rate between the two piezoelectric layers 2a and 2b can be reduced. preferable.

  Note that the end portion of the non-connecting electrode 7 is formed with an insulating resin layer that is spaced from the terminal electrodes 4a and 4b by adjusting the formation regions of the terminal electrodes 4a and 4b, or attached to the end face of the piezoelectric laminate 5. As long as insulation with the terminal electrodes 4a and 4b can be ensured by a configuration such as interposition, the piezoelectric laminate 5 may be exposed at both end faces or one end face.

Here, with reference to FIG. 6, the specific example of the piezoelectric laminated component 1 containing the piezoelectric laminated body 5 in which the non-connecting electrode 7 was formed is demonstrated. FIG. 6 is a cross-sectional view taken along line XX of another example of the embodiment of the piezoelectric laminated component 1 shown in FIG.

  In the piezoelectric laminated component 1 of this example, the non-connecting electrode 7 is not exposed on the end faces of both ends of the piezoelectric laminated body 5. At this time, when the terminal electrodes 4a and 4b are formed at both ends of the piezoelectric laminate 5, respectively, for example, a conductive method which becomes the terminal electrodes 4a and 4b uniformly over the entire areas of both ends by adopting a dip method or the like. Even when the conductive paste is applied, the terminal electrodes 4a and 4b and the non-connecting electrode 7 can be electrically disconnected. Therefore, since the terminal electrodes 4a and 4b can be easily formed, the production efficiency of the piezoelectric multilayer component 1 can be improved.

  Next, with reference to FIG. 7, another example of the piezoelectric laminated component 1 in which the non-connection electrode 7 is formed will be described. FIG. 7 is a cross-sectional view taken along line XX of another example of the embodiment of the piezoelectric laminated component 1 shown in FIG.

  According to the piezoelectric laminated component 1 of this example, the end portion of the non-connecting electrode 7 is exposed at the end face of one end portion of the piezoelectric laminated body 5, and the terminal electrodes 4 a and 4 b are connected to the non-connecting electrode 7. It is partially formed at both ends of the piezoelectric laminate 5 so as not to be connected to the end portion and to be connected to the electrode 3 disposed on the other main surface B side of the piezoelectric laminate 5 with respect to the non-connecting electrode 7. ing. In such a configuration, when the piezoelectric layers 2 and the electrodes 3 are alternately stacked when the piezoelectric multilayer component 1 is manufactured, each of the piezoelectric layers 2a on the one principal surface A side and the other piezoelectric layers 2b is provided. The configurations of the electrode 3 and the non-connecting electrode 7 can be made uniform to a configuration in which the end portion is exposed at the end face of one end portion of the piezoelectric laminate 5. Accordingly, since it is not necessary to change the way of forming the electrode 3 and the non-connection electrode 7 in each of the piezoelectric layer 2a on the one main surface A side and the other piezoelectric layers 2b, the production efficiency of the piezoelectric laminated component 1 is improved. Can be improved.

  Further, according to the piezoelectric laminated component 1 of the present invention, when the insulating ceramic layer 2a is laminated instead of the piezoelectric layer 2a on the one principal surface A side of the piezoelectric laminate 5, the one principal surface of the piezoelectric laminate 5 is obtained. Since the insulation between the electrode 3 formed on A and the electrode 3 formed between the piezoelectric layers 2 of the piezoelectric laminate 5 can be sufficiently ensured, the highly reliable piezoelectric laminate component 1 can be provided. it can.

As the material of the insulating ceramic layer 2a, it is possible to form the piezoelectric laminate 5 by firing together with the other piezoelectric layers 2b. Lead zirconate titanate (PZT), lead titanate (PT), niobium sodium-potassium acid _{(Na 1-x K x NbO} 3), bismuth layered compound _{(example: MBi 4 Ti 4 O 15,} M: 2 -valent alkaline earth metal element) be made of a piezoelectric ceramic or the like, What is not polarized may be used.

  In order to form such an insulating ceramic layer 2a made of an unpolarized piezoelectric body on the one main surface A side of the piezoelectric laminate 5, for example, when the piezoelectric laminate 5 is polarized, A method in which the electrode 3 is not formed on the main surface A can be employed. Then, by forming the electrode 3 on the one main surface A of the piezoelectric laminate 5 after the polarization is finished, the insulating ceramic layer 2a made of a non-polarized piezoelectric material is formed on the one main surface A side of the piezoelectric laminate 5. Can be formed.

  Example 1 of the piezoelectric laminated component 1 of the present invention will be described below. In Example 1, the piezoelectric laminate 5 constituting the piezoelectric laminate component 1 of the example shown in FIG. 6 was produced.

  First, a raw material powder of a ceramic material composed of lead zirconate titanate was mixed with water and a dispersing agent using a ball mill and then dried, and a binder, a solvent, a plasticizer, and the like were added to form a sheet by a doctor blade method or the like.

  Next, the silver paste used as the electrode 3 and the non-connection electrode 7 was apply | coated to the sheet | seat of this ceramic material by printing.

  Next, a predetermined number of ceramic material sheets coated with such a silver paste were laminated to form a laminate.

  Next, this laminate was cut along the dividing line into individual pieces, and then fired at a peak temperature of 1100 ° C. for 24 hours.

  Next, terminal electrodes 4a and 4b were formed on both end faces of the fired body.

  And the piezoelectric laminated body 5 was obtained by performing a polarization process by applying an electric field of about 3 kV / mm in the thickness direction at room temperature to the fired body in which the terminal electrodes 4a and 4b are formed on both end faces.

The dimensions of the piezoelectric laminate 5 were a rectangular parallelepiped shape having a length of 19 mm, a width of 3.5 mm, and a thickness of 0.5 mm. On the other hand, the dimensions of the piezoelectric layer 2a on the main surface A side were 19 mm in length, 3.5 mm in width, and 60 μm in thickness. The other piezoelectric layer 2b has a length of 19 mm and a width of 3.5 mm.
The thickness was 30 μm. The other piezoelectric layers 2b are 12 layers. Thereby, 12 layers of electrodes 3 were formed in the piezoelectric laminate 5. The electrodes 3 were formed on the one main surface A and the other main surface B of the piezoelectric laminate 5 one by one. The dimensions of the electrodes 3 were such that the length in the length direction of the piezoelectric layer 2 was 18.5 mm, the size in the width direction of the piezoelectric layer 2 was 3 mm, and the thickness was 1 μm. The thickness of the terminal electrodes 4a and 4b was 20 μm.

  In addition, in the piezoelectric layer 2a on the one main surface A side of the piezoelectric laminate 5, one layer of the non-connected electrode 7 that is not electrically connected to the terminal electrodes 4a and 4b was formed. The non-connecting electrode 7 was not exposed at the end faces of both end portions of the piezoelectric laminate 5.

  In this manufacturing process, the portion corresponding to the piezoelectric layer 2a on the one main surface A side in the piezoelectric laminate 5 is manufactured on a sheet of ceramic material having the same thickness as the other piezoelectric layers 2b by forming silver serving as the non-connecting electrode 7 The paste was applied, and a ceramic material sheet having the same thickness as the other piezoelectric layer 2b was laminated thereon.

The dimensions of the non-connecting electrode 7 were such that the length of the piezoelectric layer 2 was 18 mm, the width of the piezoelectric layer 2 was 3 mm, and the thickness was 1 μm. Further, both end portions of the non-connecting electrode 7 have a gap of 0.5 mm from the end surfaces of both end portions of the piezoelectric laminate 5, and are not exposed at the end surfaces of both end portions of the piezoelectric laminate 5. It was.

  In the piezoelectric laminate 5 produced as described above, there was no distortion and the piezoelectric laminate 5 without warping could be obtained.

  From the result of Example 1, when the non-connecting electrode 7 not electrically connected to the terminal electrodes 4a and 4b is formed in the piezoelectric layer 2a on the one main surface A side of the piezoelectric laminate 5, It has been found that the warpage of the piezoelectric laminate 5 due to the difference in thermal shrinkage between the piezoelectric layers 2a and 2b in the piezoelectric laminate 5 during sintering can be reduced.

  Example 2 of the piezoelectric laminated component 1 of the present invention will be described below. In Example 2, the piezoelectric laminate 5 constituting the piezoelectric laminate component 1 of the example shown in FIG. 7 was produced.

  In the configuration of the piezoelectric laminated component 1 of the second embodiment, the parts different from the first embodiment will be described below. The configuration other than the configuration described below was the same as the configuration of Example 1.

  In this piezoelectric laminate 5, one end of the non-connecting electrode 7 is exposed at the end face of one end of the piezoelectric laminate 5, and the terminal electrode 4 b is an exposed end of the non-connecting electrode 7. And is partially formed at the end of the piezoelectric laminate 5 so as to be connected to the electrode 3 disposed on the other main surface B side of the piezoelectric laminate 5 relative to the non-connecting electrode 7. It was supposed to be.

The dimensions of the terminal electrode 4b were 0.4 mm in the stacking direction of the piezoelectric layer 2, 3.5 mm in the width direction of the piezoelectric layer 2, and the thickness was 20 μm.

  In the piezoelectric laminate 5 manufactured by the same manufacturing method as described in the first embodiment as described above, the piezoelectric laminate 5 having no warpage and having no warpage is obtained as in the first embodiment. I was able to.

  From the results of Example 2, the end of the non-connecting electrode 7 is exposed at the end face of one end of the piezoelectric laminate 5, and the terminal electrodes 4 a and 4 b are exposed from the non-connecting electrode 7. It is not connected to the end of the piezoelectric laminate 5 and is partially formed at both ends of the piezoelectric laminate 5 so as to be connected to the electrode 3 disposed on the other main surface B side of the piezoelectric laminate 5 relative to the non-connecting electrode 7. It has been found that the warpage of the piezoelectric laminate 5 due to the difference in thermal shrinkage between the two piezoelectric layers 2a and 2b in the piezoelectric laminate 5 during sintering can be reduced. Moreover, since it was not necessary to change the method of forming the electrode 3 and the non-connection electrode 7, it turned out that the production efficiency of the piezoelectric laminated component 1 can be improved.

1: Piezoelectric laminated component 2: Piezoelectric layer 2a: Piezoelectric layer (insulating ceramic layer) on one main surface side
2b: Other piezoelectric layer 3: Electrode 4a: Terminal electrode 4b (at one end of the piezoelectric laminate): Terminal electrode 5 (at the other end of the piezoelectric laminate) 5: Piezoelectric laminate 6: Shim material 7 : Non-connecting electrode A: one main surface B: other main surface

Claims (5)

A piezoelectric laminate in which a plurality of piezoelectric layers are laminated, electrodes are formed on the piezoelectric layers, one main surface and the other main surface, and terminal electrodes connected to the electrodes are formed on both ends;
A piezoelectric laminate component including a shim material on each of which the piezoelectric laminate is attached on the one main surface side,
In each of the piezoelectric laminates, the piezoelectric layer on the one main surface side has a thickness equal to or greater than that of the other two piezoelectric layers.   2. The piezoelectric laminate according to claim 1, wherein a non-connected electrode that is not electrically connected to the terminal electrode is formed in the piezoelectric layer on the one main surface side of the piezoelectric laminate. parts.   The piezoelectric multi-layer component according to claim 2, wherein the non-connecting electrode is not exposed at end surfaces of the both end portions of the piezoelectric multi-layer body.   An end portion of the non-connecting electrode is exposed to one of end surfaces of the both end portions of the piezoelectric laminate, and the terminal electrode is not connected to the end portion of the non-connecting electrode and is not connected 3. The piezoelectric laminated body is partially formed at each of the both ends so as to be connected to the electrode disposed on the other main surface side of the piezoelectric laminated body with respect to the electrode. Piezoelectric laminated parts as described in 2.   The piezoelectric multilayer component according to any one of claims 1 to 4, wherein an insulating ceramic layer is laminated instead of the piezoelectric layer on the one main surface side of the piezoelectric laminate.

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