JP5128981B2 - Piezoelectric / electrostrictive actuator and method for manufacturing piezoelectric / electrostrictive actuator - Google Patents

Description

The present invention relates to a piezoelectric / electrostrictive actuator and a method for manufacturing a piezoelectric / electrostrictive actuator .

Piezoelectric / electrostrictive actuators have the advantage that displacement can be precisely controlled on the order of submicrons. In particular, a piezoelectric / electrostrictive actuator using a sintered body of a piezoelectric / electrostrictive porcelain composition as a piezoelectric / electrostrictive body can precisely control displacement, and has high electromechanical conversion efficiency. It has the advantages of high power, fast response speed, high durability, and low power consumption. Taking advantage of these advantages, inkjet printer heads, diesel engine injectors, hydraulic servo valves, VTR heads, piezoelectrics It is used for ceramic display pixels.

  An example of such a conventional piezoelectric / electrostrictive actuator will be described with reference to FIG. FIG. 30 is a schematic diagram of a conventional piezoelectric / electrostrictive element 8 employed as an actuator in a head of an ink jet printer, and is a cross-sectional view of the piezoelectric / electrostrictive element 8.

  As shown in FIG. 30, the piezoelectric / electrostrictive element 8 includes a lower layer electrode film 812, a lower layer piezoelectric / electrostrictive film 816, an inner layer electrode film 818, and an upper layer piezoelectric / electrostrictive body on the thin portion 804 of the base 802. The film 820 and the upper electrode film 814 are stacked in this order. In the piezoelectric / electrostrictive element 8, by applying a drive signal between the outer electrode film (lower electrode film 812 and upper electrode film 814) 810 and the inner electrode film 818, the thin portion 804, lower electrode film 812, lower layer The laminated body 808 of the piezoelectric / electrostrictive film 816, the inner electrode film 818, the upper piezoelectric / electrostrictive film 820, and the upper electrode film 814 can be flexibly vibrated.

  Patent Document 1 is a prior art document related to a conventional piezoelectric / electrostrictive element. In Patent Document 1, a piezoelectric / electrostrictive element (see FIG. 9) having a uniform piezoelectric / electrostrictive film thickness or a piezoelectric / electrostrictive film thickness is continuously reduced from the center toward the edge. A piezoelectric / electrostrictive element (see FIG. 10) is disclosed.

JP 2006-202990 A

  However, in the conventional piezoelectric / electrostrictive element, the amount of displacement may be insufficient, and in order to increase the amount of displacement, if the film thickness of the piezoelectric / electrostrictive film is made thin as a whole, the piezoelectric / electrostrictive element is under high humidity. There has been a problem that dielectric breakdown is likely to occur at the edge of the working region where the electrode films face each other across the strained body film.

The present invention has been made to solve this problem, and aims to increase the amount of displacement in a piezoelectric / electrostrictive actuator , and further, at least the edge of an operating region under high humidity, preferably The object is to increase the amount of displacement while preventing dielectric breakdown in the entire operating region.

In order to solve the above-mentioned problems, the invention of claim 1 is a laminate in which a base having a thin part surrounded by a thick part, and a piezoelectric / electrostrictive film and an electrode film formed on the base are laminated. A piezoelectric / electrostrictive actuator that bends and vibrates the thin-walled portion and the laminated body, wherein a planar region where the thin-walled portion is formed is a bending vibration region, and passes through an antinode of a bending primary mode. A part or all of the piezoelectric / electrostrictive film is in a bending primary mode along the short direction of the bending vibration region, which is the direction of the straight line when the length of the straight line that cuts the bending vibration region is minimum. This is a piezoelectric / electrostrictive actuator having a film thickness distribution having a portion where the film thickness is thicker than the antinodes between the antinodes and nodes of the bent primary mode.

According to a second aspect of the present invention, a part or all of the piezoelectric / electrostrictive film extends along the short direction of the flexural vibration region with the antinode of the bending primary mode and the piezoelectric / electrostrictive film interposed therebetween. 2. The piezoelectric / electrostrictive actuator according to claim 1, wherein the piezoelectric / electrostrictive actuator has a film thickness distribution in which the film thickness is maximized near an edge of the operating region rather than an intermediate point with an edge of the operating region facing the electrode film.

According to a third aspect of the present invention, there is provided an operation region in which a part or all of the piezoelectric / electrostrictive film is opposed to the electrode film across the piezoelectric / electrostrictive film along the short direction of the bending vibration region. 2. The piezoelectric / electrostrictive actuator according to claim 1, wherein the actuator has a film thickness distribution in which the film thickness is maximized at the edge portion.

According to a fourth aspect of the present invention, a ratio of the maximum value to the minimum value of the film thickness of a part or all of the piezoelectric / electrostrictive film along the short direction of the bending vibration region is 1.01 or more and 3.0. 4. The piezoelectric / electrostrictive actuator according to claim 1, wherein the piezoelectric / electrostrictive actuator has a film thickness distribution as follows.

The invention of claim 5 comprises a substrate having a thin portion surrounded by a thick portion, and a laminate formed by laminating a piezoelectric / electrostrictive film and an electrode film formed on the substrate, A piezoelectric / electrostrictive actuator that flexurally vibrates the thin-walled portion and the laminated body, wherein a straight line passing through the antinode of the bending primary mode cuts the flexural vibration region, with a planar region where the thin-walled portion is formed as a flexural vibration region A part or all of the piezoelectric / electrostrictive film has a film thickness larger than the antinode of the bending primary mode along the short direction of the bending vibration region which is the direction of the straight line when the length is the minimum. A piezoelectric / electrostrictive actuator having a film thickness distribution having a thickened portion between an antinode of a bent primary mode and an edge of an operation region facing the electrode film across the piezoelectric / electrostrictive film. .

The invention of claim 6 comprises a substrate having a thin portion surrounded by a thick portion, and a laminate formed by laminating a piezoelectric / electrostrictive film and an electrode film formed on the substrate, A method of manufacturing a piezoelectric / electrostrictive actuator for bending and vibrating the thin-walled portion and the laminate, wherein (a) a step of printing a piezoelectric / electrostrictive paste, and (b) a planar region in which the thin-walled portion is formed When the piezoelectric / electrostrictive paste film obtained by the step (a) is baked and the length of the straight line passing the antinode of the bending first mode cuts the bending vibration region is minimized. A film thickness distribution having a portion where the film thickness is thicker than the antinodes of the primary bending mode is between the antinodes and nodes of the primary bending mode along the short direction of the bending vibration region that is the direction of the straight line. Obtaining the piezoelectric / electrostrictive film, and in the step (a), the piezoelectric / electrostrictive film This is a method for manufacturing a piezoelectric / electrostrictive actuator using a printing plate in which a portion where the film thickness is thicker than an antinode of the bending primary mode and a portion facing at the time of printing are openings.

  According to the present invention, the amount of displacement can be increased while preventing dielectric breakdown at the edge of the operating region under high humidity.

  According to the invention of claim 2 or claim 3, it is possible to effectively increase the amount of displacement while preventing dielectric breakdown under high humidity more effectively.

  According to the fourth aspect of the invention, the amount of displacement can be increased while preventing dielectric breakdown of the entire piezoelectric / electrostrictive film under high humidity.

  According to the invention of claim 6, the piezoelectric / electrostrictive film can be easily formed.

<Overall structure of piezoelectric / electrostrictive element>
1 and 2 are schematic views of the main part of a piezoelectric / electrostrictive element 1 according to a preferred embodiment of the present invention. FIG. 1 is a plan view of the piezoelectric / electrostrictive element 1, and FIG. 2 is a cross-sectional view of the piezoelectric / electrostrictive element 1 taken along a cutting line AA. In FIG. 1 and FIG. 2, for convenience of explanation, an XYZ orthogonal coordinate system is defined in which the lateral direction of a flexural vibration region 182 to be described later is the X-axis direction and the longitudinal direction is the Y-axis direction.

  A piezoelectric / electrostrictive element 1 shown in FIGS. 1 and 2 is an actuator that is employed in a head of an ink jet printer. However, this does not preclude the application of the present invention to piezoelectric / electrostrictive elements other than the actuators employed in the heads of inkjet printers. For example, the present invention can be applied to various actuators and sensors.

  As shown in FIG. 2, the piezoelectric / electrostrictive element 1 includes a lower electrode film 112, a lower piezoelectric / electrostrictive film 116, an inner electrode film 118, and an upper piezoelectric / electrostrictive body on the thin portion 104 of the substrate 102. It has a two-layer structure in which the film 120 and the upper electrode film 114 are laminated in this order.

  In FIG. 2, the lower electrode film 112, the lower piezoelectric / electrostrictive film 116, the inner electrode film 118, the upper piezoelectric / electrostrictive film 120, and the upper electrode film 114 formed on the substrate 102 are stacked. Although the case where the laminate 108 includes one inner electrode film 118 is shown, the case where the laminate 108 includes two or more inner electrode films 118 or the case where the laminate 108 does not include the inner electrode film 118 is also shown. It is possible to apply the present invention. Further, FIG. 2 shows a case where the laminate 108 is directly formed on the substrate 102, but the laminate 108 may be indirectly formed on the substrate 102 via an inert layer. . Furthermore, a plurality of piezoelectric / electrostrictive elements 1 can be regularly arranged at regular intervals and integrated.

<Bending vibration region>
In the piezoelectric / electrostrictive element 1, by applying a drive signal between the outer electrode film (the lower electrode film 112 and the upper electrode film 114) 110 and the inner electrode film 118, the thin portion 104 and the laminated body 108 are bent and vibrated. Can be made. Hereinafter, a region where the bending vibration is excited is referred to as a “bending vibration region”. In FIG. 1, the bending vibration region 182 is indicated by a broken-line hatching with a lower left corner.

  In the piezoelectric / electrostrictive element 1, the planar shape of the thin portion 104, that is, the planar shape of the bending vibration region 182 is rectangular. In this case, as shown in the plan view of FIG. 3, the edge 184 of the bending vibration region 182 becomes a node of the bending primary mode, and the line segment 188 extending from the center 186 of the bending vibration region 182 to both sides in the longitudinal direction is the bending primary. Become the belly of the mode. Of course, the planar shape of the bending vibration region 182 is not limited to a rectangle, and may be an ellipse shown in the plan view of FIG. 4 or a hexagon shown in the plan view of FIG. Even when the planar shape of the bending vibration region 182 is the ellipse shown in FIG. 4 or the hexagon shown in FIG. 5, the edge 184 of the bending vibration region 182 becomes a node of the bending primary mode, and the center 186 of the bending vibration region 182 is obtained. A line segment 188 extending from both sides to the longitudinal direction becomes the antinode of the bending primary mode. However, when the planar shape of the bending vibration region 182 becomes more complicated, the “line segment” does not necessarily become the antinode of the bending primary mode, but the vicinity of the central portion of the bending vibration region 182 is bent. The point which becomes the belly of primary mode is the same. 3 to 5 also define an XYZ orthogonal coordinate system in which the transverse direction of the bending vibration region 182 is the X-axis direction and the longitudinal direction is the Y-axis direction.

  The present invention can be preferably applied when the length of the bending vibration region 182 having an elongated two-dimensional shape is 1000 μm or less, more preferably when the length is 500 μm or less, and 300 μm or less. It can be particularly suitably applied to the case. This is because when the length of the bending vibration region 182 in the short direction is increased, the thin portion 104 directly restrained by the thick portion 106 is easily deformed, whereas the thin portion 104 is restrained directly by the thick portion 106. Therefore, the thin-walled portion 104 that bends and vibrates and the laminate 108 contributes less to the overall deformability of the laminate 108, and the piezoelectric / electrostrictive to be described later is reduced. This is because the significance of adopting the film thickness distribution of the body films 116 and 120 tends to be small. However, this does not mean that the present invention cannot be applied at all when the length of the bending vibration region 182 in the short direction is longer than these. Further, it is desirable that the length in the short direction of the bending vibration region 182 is 30 μm or more.

  The “short-side direction” of the bending vibration region 182 is the short side direction of the bending vibration region 182 when the planar shape of the bending vibration region 182 is the rectangle shown in FIG. 3, and the planar shape of the bending vibration region 182 is FIG. 3 is the minor axis direction of the ellipse, but generally, as shown in FIG. 3, a straight line 192 passing through a point 190 on the antinode of the bending first mode is bending vibration. This is the direction of the straight line 192 when the length L that cuts the region 182 is minimized. Of course, when the planar shape of the bending vibration region 182 is a rectangle, the straight line 192 is perpendicular to the line segment 188.

<Substrate>
The base 102 is a sintered body of an insulating material. Insulating materials include stabilizers such as calcium oxide (CaO), magnesium oxide (MgO), yttrium oxide (Y ₂ O ₃ ), ytterbium oxide (Yb ₂ O ₃ ), and cerium oxide (Ce ₂ O ₃ ). It is desirable to employ added zirconium oxide (ZrO ₂ ), that is, stabilized zirconium oxide or partially stabilized zirconium oxide.

  The base 102 has a cavity structure in which a central thin portion 104 is surrounded by a peripheral thick portion 106 and supported. By adopting a cavity structure and supporting the thin portion 104 with a small plate thickness by the thick portion 106 with a large plate thickness, the plate thickness of the thin portion 104 can be reduced while maintaining the mechanical strength of the base 102. Therefore, the rigidity of the thin wall portion 104 can be reduced, and the displacement amount of the piezoelectric / electrostrictive element 1 can be increased. The thickness of the thin portion 104 is desirably 1 μm or more and 15 μm or less. This is because if it falls below this range, the thin-walled portion 104 tends to be damaged. Further, if the range is exceeded, the displacement amount of the piezoelectric / electrostrictive element 1 tends to decrease.

<Piezoelectric / electrostrictive film>
The piezoelectric / electrostrictive films 116 and 120 are sintered bodies of piezoelectric / electrostrictive material. As the piezoelectric / electrostrictive material, it is desirable to employ a lead (Pb) -based perovskite compound. Among them, a binary system of lead titanate (PbTiO ₃ ) and lead zirconate (PbZrO ₃ ), a ternary system of lead titanate, lead zirconate and a third component, or a binary system or ternary system thereof. It is desirable to use lead-based perovskite compounds with addition of metal oxides, a ternary system consisting of lead titanate, lead zirconate and lead magnesium niobate (Pb (Mg _1/3 Nb _2/3 ) O ₃ ) It is particularly desirable to employ a lead-based perovskite compound in which nickel oxide (NiO) is added. The piezoelectric / electrostrictive films 116 and 120 are desirably formed by firing after film formation by screen printing. Of course, instead of the screen printing method, a film forming method such as a sol-gel method may be adopted.

  The firing temperature of the piezoelectric / electrostrictive films 116 and 120 is desirably 1200 ° C. or higher and 1300 ° C. or lower. This is because when the firing temperature is lower than 1200 ° C., the piezoelectric / electrostrictive films 116 and 120 tend not to be densified, and when the firing temperature is 1300 ° C. or higher, the piezoelectric / electrostrictive films 116 and 120 are likely to be decomposed. .

In firing the piezoelectric / electrostrictive films 116, 120, in order to suppress the decomposition of the piezoelectric / electrostrictive films 116, 120, the sheath is made of magnesium oxide (MgO) or aluminum oxide (Al ₂ O ₃ ). It is desirable to perform the firing in a state where the powder having the same composition as the piezoelectric / electrostrictive films 116 and 120 is contained in the sheath as an atmosphere adjusting agent.

  The average film thickness of the piezoelectric / electrostrictive films 116 and 120 is desirably 2 μm or more and 15 μm or less. When the average film thickness is less than this range, the insulation properties of the piezoelectric / electrostrictive films 116 and 120 tend to decrease. When the average film thickness exceeds this range, the amount of bending displacement tends to decrease. Because it is.

  The piezoelectric / electrostrictive films 116 and 120 are formed in a bending vibration region that becomes a node of the bending primary mode from the central portion of the bending vibration region 182 that becomes the antinode of the bending primary mode along the short direction of the bending vibration region 182. It has a film thickness distribution in which the film thickness continuously increases toward the edge of 182. By adopting such a film thickness distribution, the film thickness of the piezoelectric / electrostrictive films 116 and 120 is increased at the end portions of the outer electrode film 110 and the inner electrode film 118, so that dielectric breakdown can be prevented and Since the film thickness of the piezoelectric / electrostrictive films 116 and 120 is reduced and the rigidity of the piezoelectric / electrostrictive films 116 and 120 is reduced at the antinode of the bending primary mode, the displacement amount of the piezoelectric / electrostrictive element 1 is increased. be able to. Increasing the film thickness of the piezoelectric / electrostrictive films 116 and 120 at the end portions of the outer electrode film 110 and the inner electrode film 118 is effective in preventing dielectric breakdown. This is because there is a tendency to increase from the antinodes of the bent primary mode toward the end portions of the outer electrode film 110 and the inner electrode film 118.

  In order to obtain such an effect, when the film thickness distribution of the piezoelectric / electrostrictive films 116 and 120 is observed along the short direction of the bending vibration region 1, the central portion of the bending vibration region 182 is used. However, it is sufficient to have a portion where the film thickness is increased between the center portion and the edge portion of the bending vibration region 182. Therefore, it is not essential that the film thickness increases “continuously”, and as shown in the schematic diagram of FIG. 6, the film thickness increases from the center of the bending vibration region 282 toward the edge of the bending vibration region 282. May be "discontinuously" thickening. 6 shows a cross section of the piezoelectric / electrostrictive element 2 having a single-layer structure in which a lower electrode film 212, a piezoelectric / electrostrictive film 216, and an upper electrode film 214 are laminated in this order on the thin portion 204 of the base 202. FIG. It is a figure. 6 also defines an XYZ orthogonal coordinate system in which the lateral direction of the bending vibration region 282 is the X-axis direction and the longitudinal direction is the Y-axis direction.

  In order to effectively avoid the dielectric breakdown, the edge of the working region 194 where the outer layer electrode film 110 and the inner layer electrode film 118 are opposed to each other with the antinode of the bending primary mode sandwiched between the piezoelectric / electrostrictive films 116 and 120 It is desirable that the film thicknesses of the piezoelectric / electrostrictive films 116 and 120 be maximized closer to the edge of the operating region 194 than the intermediate point.

  In order to particularly effectively avoid the dielectric breakdown, the piezoelectric / electrostrictive film is formed at the end of the working region 194 where the outer electrode film 110 and the inner electrode film 118 face each other with the piezoelectric / electrostrictive films 116 and 120 interposed therebetween. It is desirable to maximize the thickness of the body films 116 and 120.

  Furthermore, the ratio of the maximum value to the minimum value of the film thickness of the piezoelectric / electrostrictive films 116 and 120 is desirably 1.01 or more and 3.0 or less. If it falls below this range, it tends to be difficult to increase the amount of displacement while avoiding dielectric breakdown. If this range is exceeded, the film thickness at the center of the flexural vibration region 182 becomes too thin and the flexural vibration region This is because the electric field concentrates at the center of 182 and dielectric breakdown tends to occur.

In the piezoelectric / electrostrictive element 1, all of the plurality of piezoelectric / electrostrictive films (lower piezoelectric / electrostrictive film 116 and upper piezoelectric / electrostrictive film 120) separated by the internal electrode layer 118 are in a flexural vibration region. It has a film thickness distribution in which the film thickness continuously increases from the center to the end of the bending vibration region 182 along the short direction of 182. However, as shown in the schematic diagram of FIG. 7, a part of the plurality of piezoelectric / electrostrictive films (lower piezoelectric / electrostrictive film 316 and upper piezoelectric / electrostrictive film 320) (in FIG. 7, upper piezoelectric / electrostrictive film 320). Only the electrostrictive body film 320) has a film thickness distribution in which the film thickness continuously increases from the center to the end of the bending vibration region 382 along the short direction of the bending vibration region 382. However, it is possible to obtain an effect of increasing the amount of displacement while preventing dielectric breakdown. In FIG. 7, the lower electrode film 312, the lower piezoelectric / electrostrictive film 316, the inner electrode film 318, the upper piezoelectric / electrostrictive film 320 and the upper electrode film 314 are arranged in this order on the thin portion 304 of the substrate 302. 2 is a cross-sectional view of a piezoelectric / electrostrictive element 3 having a laminated two-layer structure. 7 also defines an XYZ orthogonal coordinate system in which the lateral direction of the bending vibration region 382 is the X-axis direction and the longitudinal direction is the Y-axis direction. When only a part of the plurality of piezoelectric / electrostrictive films has the above-mentioned film thickness distribution, the uppermost piezoelectric / electrostrictive film 320 of the uppermost layer should have the above-mentioned film thickness distribution. Is desirable. This is because the uppermost piezoelectric / electrostrictive film 320 of the uppermost layer is most susceptible to humidity.

  In addition, in the piezoelectric / electrostrictive element 1, the operation region 194 is included inside the bending vibration region 182, but the operation region 494 protrudes outside the bending vibration region 482 as shown in the sectional view of FIG. It may be. In this case, when the film thickness distribution of the piezoelectric / electrostrictive films 416 and 420 is observed along the short direction of the bending vibration region 482, the portion where the film thickness is thicker than the central portion of the bending vibration region 482. Between the center of the bending vibration region 482 and the end of the operation region 494 is sufficient. In FIG. 8, the lower electrode film 412, the lower piezoelectric / electrostrictive film 416, the inner electrode film 418, the upper piezoelectric / electrostrictive film 420, and the upper electrode film 414 are arranged in this order on the thin portion 404 of the substrate 402. 2 is a cross-sectional view of a piezoelectric / electrostrictive element 4 having a laminated two-layer structure. 8 also defines an XYZ orthogonal coordinate system in which the lateral direction of the bending vibration region 482 is the X-axis direction and the longitudinal direction is the Y-axis direction.

<Inner electrode film>
The inner electrode film 118 is a sintered body of platinum or an alloy containing platinum as a main component. Of course, as long as it can withstand simultaneous firing, the inner electrode film 118 is not prevented from being made of another conductive material.

  The film thickness of the inner electrode film 118 is desirably 0.5 μm or more and 3.0 μm or less. This is because if the thickness falls below this range, the inner electrode film 118 tends to break during simultaneous firing. Further, if the amount exceeds this range, the amount of displacement tends to decrease.

  The inner layer electrode film 118 is also preferably formed by firing after film formation by screen printing. Of course, a film forming method other than the screen printing method may be employed.

<Outer electrode film>
The outer electrode film 112 is desirably a sintered body of platinum (Pt) to which titanium oxide (TiO ₂ ) is added. Of course, a conductive material other than platinum to which titanium oxide is added may be used.

  The outer electrode film 114 is preferably a gold (Au) sintered body. Of course, a conductive material other than gold may be employed.

The outer electrode films 112 and 114 are also preferably formed by firing after film formation by screen printing. Of course, a film forming method other than the screen printing method may be employed.

<Formation of piezoelectric / electrostrictive film by screen printing method>
In order to form the piezoelectric / electrostrictive films 116 and 120 having the above-described film thickness distribution on a flat film formation surface by a screen printing method, screen printing may be repeated a plurality of times. For example, after a screen-printed piezoelectric / electrostrictive body in the form of a paste is screened on the central portion using a first screen mask in which the non-central portion is covered with an emulsion and the central portion is an opening, As shown in the cross-sectional view, the paste / piezoelectric / electrostrictive body is non-centered using the second screen mask 5 in which the central portion 51 is closed with the emulsion 501 and the non-central portion 52 is an opening. What is necessary is just to screen-print on the part 52. FIG. According to such screen printing, since the emulsion 501 of the second screen mask 5 comes into contact with the piezoelectric / electrostrictive body of the central portion 51 that has already been screen-printed, the printing surface of the second screen mask 5 is the first surface. A piezoelectric / electrostrictive film that is higher than the printing surface of the first screen mask and has a larger film thickness than the central portion 51 can be obtained in the non-central portion 52.

  Here, if the viscosity of the paste of the piezoelectric / electrostrictive body used for screen printing is lowered, the level difference between the central part and the non-central part becomes smooth, and the above-mentioned “continuously thickening” piezoelectric / electrostrictive A body film can be obtained, and if the viscosity is increased, the above-mentioned “discontinuously thickening” piezoelectric / electrostrictive film can be obtained.

  Further, as shown in the cross-sectional view of FIG. 9, instead of the screen mask 5 in which the emulsion 501 blocking the central portion 51 protrudes from the screen mesh 505 toward the printing surface, as shown in the cross-sectional view of FIG. Alternatively, the screen mask 6 in which the emulsion 601 blocking the central portion 61 does not protrude from the screen mesh 605 can be used. According to the screen mask 6 shown in the cross-sectional view of FIG. 10, it becomes possible for the paste of piezoelectric / electrostrictive body that has entered from the non-central portion 62 that becomes the opening to wrap around the central portion 61 blocked by the emulsion 601. It becomes easy to ensure the continuity of the film thickness of the formed piezoelectric / electrostrictive film.

  In addition, screen printing in the central part and screen printing in the non-central part are not performed once each, but screen printing in the central part may be repeated twice or more, or screen printing in the non-central part is repeated twice or more. May be.

  In addition, screen printing in the central part may be performed after screen printing in the non-central part, instead of screen printing in the non-central part after screen printing in the central part. And non-center screen printing may be performed alternately. In the latter case, screen printing at the central portion may be performed twice or more, and screen printing at the non-central portion may be performed twice or more.

  Further, instead of dividing the screen into two areas of the central part and the non-central part, screen printing is allowed to be divided into three areas or more.

  In addition, when screen printing is performed using a metal mask without a screen mesh, if a squeegee with low hardness made of urethane resin or the like is used, the piezoelectric film having the above-described film thickness distribution by passing through the central portion serving as the opening. / The electrostrictive films 116 and 120 can be formed by one screen printing. In addition, since a piezoelectric / electrostrictive film having a flat surface can be formed by using a squeegee with high hardness, a piezoelectric film having the above-described film thickness distribution on the film formation surface having a convex central portion. / The electrostrictive films 116 and 120 can be similarly formed by one screen printing. In these cases, if a metal mask to which an emulsion is added is used, problems such as bleeding can be suppressed, and the piezoelectric / electrostrictive films 116 and 120 having the above-described film thickness distribution can be stably formed. Can do.

  In addition, when the screen printing is performed using the metal mask, the first metal mask in which the non-central portion is closed and the central portion is an opening, as in the case where the screen printing is performed using the screen mask. After the paste-like piezoelectric / electrostrictive body is screen-printed in the central portion using the second metal mask having the central portion closed and the non-central portion opened, the paste is formed. The piezoelectric / electrostrictive body thus made can be screen-printed on the non-central portion.

  11 to 15 are schematic views of metal masks 7a to 7e that can be used as the second metal mask. 11 to 15 are perspective views of the metal masks 7a to 7e.

  As shown in FIG. 11, the metal mask 7a has a structure in which an opening 72a is formed in a metal plate 71a having a substantially uniform plate thickness. The opening 72a is formed in a non-central portion that opposes a portion where the film thickness of the piezoelectric / electrostrictive films 116, 120 is thicker than the bending primary mode antinode during screen printing.

  As shown in FIG. 12, the metal mask 7b has a structure in which an opening 72b is formed in a metal plate 71b whose central portion is thinner than the non-central portion. The opening 72b is formed at a non-central portion facing the portion where the film thickness of the piezoelectric / electrostrictive films 116, 120 is thicker than the antinode of the bending primary mode during screen printing. According to the metal mask 7b shown in the perspective view of FIG. 12, it becomes possible for the paste of the piezoelectric / electrostrictive body that has entered from the non-central portion that becomes the opening 72b to wrap around the central portion blocked by the metal plate 71b. It becomes easy to ensure the continuity of the film thickness of the formed piezoelectric / electrostrictive films 116 and 120.

  It is also desirable to use metal masks 7c to 7e in which emulsion layers 73c to 73e are added to the printing surface side of the metal plates 71c to 71e.

  As shown in FIG. 13, the metal mask 7c has a structure in which an emulsion layer 73c is added to the printing surface side of the metal plate 71c having a substantially uniform thickness and an opening 72c is formed. The opening 72c is formed in a non-central portion that opposes a portion where the film thickness of the piezoelectric / electrostrictive films 116 and 120 is thicker than the antinode of the bending primary mode during screen printing. The emulsion layer 73c is added to the entire non-opening except for the opening 72c on the printing surface side of the metal plate 71c.

  As shown in FIG. 14, the metal mask 7d has a structure in which an emulsion layer 73d is added and an opening 72d is formed on a metal plate 71d whose central portion is thinner than the non-central portion. The opening 72d is formed at a non-central portion facing the portion where the piezoelectric / electrostrictive films 116, 120 are thicker than the antinode of the bending primary mode during screen printing. The emulsion layer 73d is added to the entire non-opening except for the opening 72d on the printing surface side of the metal plate 71d.

  As shown in FIG. 15, the metal mask 7e has a structure in which an emulsion layer is added to the metal plate 71e whose central portion is thinner than the non-central portion and an opening 72e is formed. The opening 72e is formed in a non-central portion facing the portion where the film thickness of the piezoelectric / electrostrictive films 116, 120 is thicker than the antinode of the bending primary mode during screen printing. The emulsion layer 73e is added only to the central portion that occupies a part of the non-opening except the opening 72e on the printing surface side of the metal plate 71e.

  Thus, by adding the emulsion layers 73c to 73e softer than the metal plates 71c to 71e to the printing surface side, the hard metal plates 71c to 71e do not come into contact with the film formation surface and the soft emulsion layers 73c to 73e are formed. Since it comes into contact with the film surface, the adhesion between the metal masks 7c to 7e and the film formation surface can be improved.

  A portion where the film thickness of the piezoelectric / electrostrictive films 116 and 120, which is typified by the screen masks 5 and 6 and the metal masks 7a to 7e, is thicker than the antinodes of the bending primary mode, and a portion facing when screen printing is performed. By using a printing plate having an opening, the piezoelectric / electrostrictive films 116 and 120 can be easily formed.

<Formation of piezoelectric / electrostrictive film by removing unnecessary piezoelectric / electrostrictive body by etching>
In order to form the piezoelectric / electrostrictive films 116 and 120 having the above-described film thickness distribution by the sol-gel method, a piezoelectric / electrostrictive sol-gel solution is applied to the film-forming surface having a convex central portion. Then, an unnecessary piezoelectric / electrostrictive body may be removed by etching.

<Experiment>
In the following, while changing the film thickness distribution of the piezoelectric / electrostrictive films 116 and 120, the piezoelectric / electrostrictive element 1 shown in FIGS. 1 and 2 was produced, and the produced piezoelectric / electrostrictive element 1 was evaluated. The results will be described with reference to the flowchart of FIG.

  In producing the piezoelectric / electrostrictive element 1, first, the base 102 was produced (step S101). The substrate 102 was prepared by firing a ceramic green laminate in which ceramic green sheets of partially stabilized zirconium oxide were laminated at a temperature of 1450 ° C.

  Subsequently, the laminated body 108 was formed on the thin portion 104 of the base body 102 (Steps S102 to S109).

  In forming the laminated body 108, first, a lower layer electrode paste containing platinum powder and titanium oxide powder is applied onto the thin wall portion 104 by a screen printing method (step S102), and the formed lower layer electrode film 112 is applied. Firing was performed at 1300 ° C. (step S103). As a result, a sintered body of the lower electrode film 112 integrated with the base body 102 was obtained.

Subsequently, the piezoelectric / electrostrictive paste including the calcined piezoelectric / electrostrictive material powder, the inner layer electrode paste including the platinum powder, and the piezoelectric / electrostrictive paste are sequentially applied by screen printing (steps S104 to S104). S106), the formed lower piezoelectric / electrostrictive film 116, inner electrode film 118, and upper piezoelectric / electrostrictive film 120 were simultaneously fired at 1250 ° C. (step S107). As a result, a sintered body of the lower layer piezoelectric / electrostrictive film 116, the inner layer electrode film 118, and the upper layer piezoelectric / electrostrictive film 120 integrated with the substrate 102 and the lower layer electrode film 112 was obtained. The piezoelectric / electrostrictive material, was used _{20Pb (Mg 0.87 / 3 Ni 0.13} / 3 Nb 2/3) O 3 -43PbTiO 3 -37PbZrO 3.

  Subsequently, an upper electrode paste containing gold powder was applied by screen printing (step S108), and the formed upper electrode film 114 was baked at 800 ° C. (step S109). Thereby, a sintered body of the upper electrode film 114 was obtained.

  In the formation of the laminated body 108, the planar pattern of the lower electrode film 112, the lower piezoelectric / electrostrictive film 116, the inner electrode film 118, the upper piezoelectric / electrostrictive film 120, and the upper electrode film 114 is the same as that of the lower electrode film 112. The upper electrode film 114 is electrically at the same potential, the lower electrode film 112 and the inner electrode film 116 are opposed to each other with the lower piezoelectric / electrostrictive film 116 interposed therebetween, and the inner electrode film 118 and the upper electrode film 114 are upper layers. A film facing the piezoelectric / electrostrictive film 120 is used. The film thicknesses after firing of the lower electrode film 112, the inner electrode film 118, and the upper electrode film 114 are 1.0 to 2.0 μm, 1.0 to 1.5 μm, and 0.1 to 0.4 μm, respectively. The film thickness and width during application of the lower layer electrode paste, inner layer electrode paste, and upper layer electrode paste were adjusted so that the width (length in the short direction) was 140 μm. Further, the piezoelectric / electrostrictive paste of the piezoelectric / electrostrictive paste is adjusted so that the average film thickness after firing of the lower piezoelectric / electrostrictive film 116 and the upper piezoelectric / electrostrictive film 120 becomes 6.5 μm and 7.0 μm, respectively. The film thickness at the time of application was adjusted.

  After the formation of the laminate 108, the piezoelectric / electrostrictive element 1 was subjected to polarization treatment by applying a voltage of 100 V between the outer electrode film 110 and the inner electrode film 118 at a temperature of 60 ° C. (step S110). .

  Then, the amount of bending displacement was measured. The displacement amount is obtained by measuring the displacement amount when a driving voltage of 30 V is applied between the inner layer electrode film 118 and the outer layer electrode film 110 with a laser Doppler displacement meter. Further, a bias voltage of 30 V was applied to the piezoelectric / electrostrictive element 1 under high humidity for 30 hours, and the presence or absence of dielectric breakdown was examined with an optical microscope having a magnification of 150 times. The presence / absence of dielectric breakdown is determined in consideration of the fact that a circular rupture mark having a diameter of about 20 μm is observed in the piezoelectric / electrostrictive element 1 in which the dielectric breakdown has caused a substantial problem. Judgment was made based on whether or not was observed.

  Examples 1 to 18 in the tables shown in FIGS. 17 to 20 are for the piezoelectric / electrostrictive element 1 in which the film thickness distributions of the piezoelectric / electrostrictive films 116 and 120 are variously changed within the scope of the present invention. The displacement amount and the evaluation result of the insulation are shown, and Comparative Examples 1 and 2 in the lists shown in FIGS. 17 to 20 show the film thickness distribution of the piezoelectric / electrostrictive films 116 and 120 of the present invention. The piezoelectric / electrostrictive element 1 outside the range shows the displacement and the evaluation results of the insulation. The “displacement amount” shown in FIGS. 17 to 20 is an average value for 30 or more piezoelectric / electrostrictive elements. The measurement variation of the displacement amount is generally ± 0.001 μm. Further, “◯” in the “insulating” column means that dielectric breakdown did not occur in the entire piezoelectric / electrostrictive film 116, 120, and “x” represents the piezoelectric / electrostrictive film 116, 120. It means that a dielectric breakdown has occurred at any of 120 locations. “Δ” means that dielectric breakdown did not occur at the edge of the operating region 194.

{About the film thickness at the edge of the working area}
In Examples 1 to 7 of FIG. 17, the piezoelectric / electrostrictive element 1 in which the film thickness of the lower piezoelectric / electrostrictive film 116 and the upper piezoelectric / electrostrictive film 120 is maximized at the edge A of the operating region 194 is as follows. The lower piezoelectric / electrostrictive film at the edge A of the working region 194 with the film thickness TE of the lower piezoelectric / electrostrictive film 116 and the upper piezoelectric / electrostrictive film 120 at the center E of the bending vibration region 182 being constant. 116 shows the displacement and insulation evaluation results when the film thickness TA of 116 and the upper piezoelectric / electrostrictive film 120 is changed. In Comparative Example 1 of FIG. 17, the piezoelectric / electrostrictive element in which the film thickness TA at the edge A of the piezoelectric / electrostrictive element 1 of Examples 1 to 7 is thinner than the film thickness TE at the center E is displaced. The evaluation result of quantity and insulation is shown. Here, the film thickness TA at the edge A shown in FIG. 17 is a relative value when the film thickness TE at the center E is set to “1” which is a reference value. This also applies to FIGS. 18 to 20 described later.

  As shown in FIG. 17, in Comparative Example 1 in which the thickness ratio TA / TE, which is the ratio of the film thickness TA at the edge A to the film thickness TE at the center E, is 0.70, the displacement is 0.328 μm. On the other hand, in Examples 1-7 (refer to Drawing 22) whose thickness ratio TA / TE is 1.01-4.00, the amount of displacement has increased to 0.344-0.362 micrometers. In particular, in Examples 1 to 6 in which the thickness ratio TA / TE is 1.01 to 3.00, the displacement greatly increases to 0.355 to 0.362 μm, and the entire piezoelectric / electrostrictive films 116 and 120 are obtained. Insulation breakdown can be prevented. That is, in order to increase the amount of displacement, the thickness ratio TA / TE is preferably 1.01 or more, more preferably 1.01 to 3.00, and the piezoelectric / electrostrictive films 116 and 120. In order to prevent dielectric breakdown in the whole, it can be said that the thickness ratio TA / TE is preferably set to 1.01 to 3.00.

{About the film thickness at the center of the flexural vibration region}
In Examples 8 to 14 of FIG. 18, the piezoelectric / electrostrictive element 1 in which the film thickness of the upper piezoelectric / electrostrictive film 120 is maximum at the intermediate point C between the edge A and the center E is The film thickness TC of the upper piezoelectric / electrostrictive film 120 at the intermediate point C while keeping the film thickness TA of the upper piezoelectric / electrostrictive film 120 and the film thickness TE of the upper piezoelectric / electrostrictive film 120 at the center E constant. The displacement amount and the evaluation result of the insulating property when changing is shown. In Examples 8 to 14, the film thickness of the lower piezoelectric / electrostrictive film 116 is maximized at the edge A of the operation region 194, and the film thickness of the lower piezoelectric / electrostrictive film 116 at the center E is set to the reference value. In the case of “1”, the film thickness of the lower layer piezoelectric / electrostrictive film 116 at the edge A is “1.5”.

  As shown in FIG. 18, Examples 8 to 13 in which the thickness ratio TC / TE, which is the ratio of the film thickness TC at the intermediate point C to the film thickness TE in the center E, is 1.01 to 3.00 (see FIG. 23). ), The displacement amount is 0.340 to 0.352 μm, which is larger than 0.328 μm of Comparative Example 1, and good insulation is also obtained. However, in Example 14 (see FIG. 23) in which the thickness ratio TC / TE is 4.00, there is a tendency that the amount of displacement is reduced and a tendency that dielectric breakdown other than the edge A is likely to occur. That is, it can be said that the thickness ratio TM / TE is desirably set to 1.01 to 3.00 in order to increase the amount of displacement and the insulation and prevent the dielectric breakdown of the entire piezoelectric / electrostrictive films 116 and 120.

{Regarding the position of the maximum thickness point M}
Examples 3, 15, 10, and 16 in FIG. 19 are ratios of the maximum value TM of the film thickness of the upper piezoelectric / electrostrictive film 120 to the film thickness TE of the upper piezoelectric / electrostrictive film 120 at the center E. For the piezoelectric / electrostrictive element 1 having a thickness ratio TM / TE of 1.5, the film thickness maximum point M at which the film thickness of the upper piezoelectric / electrostrictive film 120 is maximum is between the edge A and the center E. The displacement amount and the insulation evaluation result when moved by the are shown. Also in Examples 3, 15, 10, and 16, the film thickness of the lower layer piezoelectric / electrostrictive film 116 is maximized at the edge A of the operating region 194, and the film thickness of the lower layer piezoelectric / electrostrictive film 116 at the center E. Is the reference value “1”, the film thickness of the lower layer piezoelectric / electrostrictive film 116 at the edge A is “1.5”.

  As shown in FIG. 19, Example 3 (see FIG. 22) where the film thickness maximum point M is at the edge A, and the film thickness maximum point M is at the quarter point B between the edge A and the intermediate point C. In Example 15 (see FIG. 24) and Example 10 (see FIG. 23) in which the film thickness maximum point M is at the intermediate point C, the displacement amount is 0.345 to 0.358 μm, which is larger than 0.328 μm in Comparative Example 1. Therefore, good insulation is also obtained. However, in Example 16 (see FIG. 25) in which the film thickness maximum point M is at the quarter point D between the intermediate point C and the central portion E, the displacement amount tends to decrease and the insulation properties deteriorate. The tendency to do is seen. That is, in order to increase the amount of displacement and ensure insulation, it is desirable that the edge portion A is closer to the film thickness maximum point M than the intermediate point C.

{About the film thickness at the center of the flexural vibration region}
In Examples 3 and 17 of FIG. 20, the piezoelectric / electrostrictive film 1 having the maximum film thickness of the upper piezoelectric / electrostrictive film 120 at the edge A is obtained from the upper piezoelectric / electrostrictive film 120 at the edge A. The displacement amount and the insulation evaluation results are shown when the film thickness TE of the upper piezoelectric / electrostrictive film 120 at the center E is changed while the film thickness TA is kept constant. Further, in Example 18 of FIG. 20, the displacement amount and the insulating property of the piezoelectric / electrostrictive element 1 in which the film thickness maximum point M of the piezoelectric / electrostrictive element 1 of Example 17 is moved from the edge A to the intermediate point C are shown. The evaluation results are shown. Further, in Comparative Example 2 of FIG. 20, the film thickness TA of the upper piezoelectric / electrostrictive film 120 at the edge A of the piezoelectric / electrostrictive element 1 of Examples 3 and 17 is set to the upper piezoelectric / electrostrictive body at the center E. For the piezoelectric / electrostrictive element made thinner than the film thickness TE of the film 120, the displacement amount and the evaluation results of the insulating properties are shown. In Examples 3, 17, and 18 and Comparative Example 2, the film thickness of the lower layer piezoelectric / electrostrictive film 116 is maximized at the edge A of the operation region 194, and the lower layer piezoelectric / electrostrictive film 116 at the center E. When the film thickness is the reference value “1”, the film thickness of the lower layer piezoelectric / electrostrictive film 116 at the edge A is “1.5”.

  As shown in FIG. 20, in Example 3 (see FIG. 22), 1.10 where the thickness ratio TA / TE, which is the ratio of the film thickness TA of the edge A to the film thickness TE in the center E, is 1.50. In Example 17 (see FIG. 26), the displacement amount is 0.358 to 0.359 μm and the thickness ratio TA / TE is increased from 0.224 μm in Comparative Example 2 (see FIG. 27), which is 0.8. Good insulation is also obtained. The same applies to Example 18 (see FIG. 28) in which the maximum film thickness point M is moved.

  22 to 28 are schematic views of the piezoelectric / electrostrictive element 1 corresponding to FIG.

  In addition to these, as shown in the schematic diagram of the piezoelectric / electrostrictive element 1 in FIG. 29, the lower layer piezoelectric / electrostrictive film 116 is short in the flexural vibration region 182 as in the conventional piezoelectric / electrostrictive element 8. The film thickness distribution is such that the film thickness continuously decreases from the center E toward the edge A along the direction. Even when the film thickness distribution is such that the film thickness continuously increases from the center E toward the edge A along the hand direction, In addition, it has been confirmed that the same effect can be obtained with respect to prevention of dielectric breakdown.

  FIG. 21 shows the displacement and insulation evaluation results for piezoelectric / electrostrictive elements that employ a single-layer structure that does not include the inner electrode film 108 and have various thickness ratios of the piezoelectric / electrostrictive film. As shown in FIG. 21, in Comparative Example 3 outside the scope of the present invention where the thickness ratio is 0.7, the displacement amount is 0.166 μm, whereas the thickness ratio is 1.01. In Example 19 within the scope of the present invention, the displacement is increased to 0.181 μm, and in Examples 20 to 26 within the scope of the present invention in which the thickness ratio is 1.1 to 4.0, the displacement The amount is further increased to 0.201-0.210 μm. Moreover, in Examples 19-24 whose thickness ratio is 1.01 or more and 3.00 or less, favorable insulation is also acquired. That is, even in the case of a single layer structure, in order to increase the amount of displacement, the thickness ratio is preferably greater than 1, more preferably 1.1 or more, and the piezoelectric / electrostrictive films 116 and 120 In order to prevent the overall breakdown, it can be said that the thickness ratio is desirably set to 1.01 or more and 3.0 or less.

1 is a plan view of a piezoelectric / electrostrictive element according to a preferred embodiment. It is sectional drawing of the piezoelectric / electrostrictive element which concerns on desirable embodiment. It is a top view of a rectangular bending vibration area | region. It is a top view of an elliptical bending vibration area | region. It is a top view of a hexagonal bending vibration region. It is sectional drawing of the piezoelectric / electrostrictive element which concerns on another example. It is sectional drawing of the piezoelectric / electrostrictive element which concerns on another example. It is sectional drawing of the piezoelectric / electrostrictive element which concerns on another example. It is sectional drawing of a screen mask. It is sectional drawing of a screen mask. It is a perspective view of a metal mask. It is a perspective view of a metal mask. It is a perspective view of a metal mask. It is a perspective view of a metal mask. It is a perspective view of a metal mask. It is a flowchart explaining the manufacturing method of a piezoelectric / electrostrictive element. It is a figure which shows the displacement amount and the evaluation result of insulation. It is a figure which shows the displacement amount and the evaluation result of insulation. It is a figure which shows the displacement amount and the evaluation result of insulation. It is a figure which shows the displacement amount and the evaluation result of insulation. It is a figure which shows the displacement amount and the evaluation result of insulation. It is sectional drawing of a piezoelectric / electrostrictive element. It is sectional drawing of a piezoelectric / electrostrictive element. It is sectional drawing of a piezoelectric / electrostrictive element. It is sectional drawing of a piezoelectric / electrostrictive element. It is sectional drawing of a piezoelectric / electrostrictive element. It is sectional drawing of a piezoelectric / electrostrictive element. It is sectional drawing of a piezoelectric / electrostrictive element. It is sectional drawing of a piezoelectric / electrostrictive element. It is sectional drawing of the conventional piezoelectric / electrostrictive element.

Explanation of symbols

1, 2, 3, 4 Piezoelectric / electrostrictive element 112, 212, 312, 412 Lower electrode film 116, 316, 416 Lower piezoelectric / electrostrictive film 216 Piezoelectric / electrostrictive film 118, 318, 418 Inner electrode film 120 , 320, 420 Upper layer piezoelectric / electrostrictive film 114, 214, 314, 414 Upper layer electrode film 182, 282, 383, 482 Bending vibration region 194, 494 Operating region

Claims (6)

A substrate having a thin portion surrounded by a thick portion;
A laminate formed by laminating a piezoelectric / electrostrictive film and an electrode film formed on the substrate;
With
A piezoelectric / electrostrictive actuator that flexurally vibrates the thin portion and the laminate,
The plane region where the thin-walled portion is formed is defined as a bending vibration region, and the short side of the bending vibration region which is the direction of the straight line when the straight line passing through the antinode of the bending primary mode is minimum A film thickness distribution in which part or all of the piezoelectric / electrostrictive film along the direction has a portion between the antinodes of the bent primary mode and the nodes where the film thickness is thicker than the antinodes of the bent primary mode. Having
Piezoelectric / electrostrictive actuator . A working region in which a part or all of the piezoelectric / electrostrictive film is opposed to the electrode film across the piezoelectric / electrostrictive film with the antinode of the bending primary mode sandwiched along the short direction of the bending vibration area. Having a film thickness distribution in which the film thickness is maximized near the edge of the working region rather than an intermediate point with the edge of
The piezoelectric / electrostrictive actuator according to claim 1. Along the lateral direction of the bending vibration region, a part or all of the piezoelectric / electrostrictive film has a film thickness at the edge of the working region where the electrode film is opposed to the piezoelectric / electrostrictive film. Having a maximum film thickness distribution,
The piezoelectric / electrostrictive actuator according to claim 1. A film thickness distribution in which a part or all of the piezoelectric / electrostrictive film has a ratio of a maximum value to a minimum value of 1.01 or more and 3.0 or less along the short direction of the bending vibration region. Have
The piezoelectric / electrostrictive actuator according to any one of claims 1 to 3. A substrate having a thin portion surrounded by a thick portion;
A laminate formed by laminating a piezoelectric / electrostrictive film and an electrode film formed on the substrate;
With
A piezoelectric / electrostrictive actuator that flexurally vibrates the thin portion and the laminate,
The plane region where the thin-walled portion is formed is defined as a bending vibration region, and the short side of the bending vibration region which is the direction of the straight line when the straight line passing through the antinode of the bending primary mode is minimum A part or all of the piezoelectric / electrostrictive film along the direction has a portion where the film thickness is thicker than that of the bent primary mode, and sandwiches the piezoelectric / electrostrictive film with the bent primary mode antinode. And having a film thickness distribution between the electrode film and the edge of the working region facing each other,
Piezoelectric / electrostrictive actuator . A substrate having a thin portion surrounded by a thick portion;
A laminate formed by laminating a piezoelectric / electrostrictive film and an electrode film formed on the substrate;
With
A method of manufacturing a piezoelectric / electrostrictive actuator that flexurally vibrates the thin portion and the laminate,
(a) printing a piezoelectric / electrostrictive paste;
(b) Using the planar region where the thin-walled portion is formed as a bending vibration region, the piezoelectric / electrostrictive paste film obtained in the step (a) is baked, and the straight line passing through the antinode of the bending first mode is bent. A portion where the film thickness is thicker than that of the bending primary mode along the short direction of the bending vibration region, which is the direction of the straight line when the length that cuts the vibration region is minimum, is the antinode of the bending primary mode. Obtaining the piezoelectric / electrostrictive film having a thickness distribution between and
With
In the step (a), the piezoelectric / electrostrictive to use printing plate portion thickness of the piezoelectric / electrostrictive film is opposed to the time of printing the thickened portion than the belly of the bending first-order mode is an opening A manufacturing method of a strain actuator .

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