Laminated piezoelectric actuator and method for manufacturing laminated piezoelectric actuator

Abstract

The invention relates to the technical field of piezoelectric actuators, in particular to a laminated piezoelectric actuator and a manufacturing method of the laminated piezoelectric actuator. The laminated piezoelectric driver comprises a piezoelectric driving main body; the piezoelectric driving main body comprises a piezoelectric ceramic body, a driving part, a side positive electrode group and a through negative electrode, and the driving part comprises a plurality of driving electrode layers which are stacked in a first direction; in the plurality of driving electrode layers, at least one driving electrode layer is a positive electrode layer, and at least one driving electrode layer is a first negative electrode layer; the orthographic projection of the positive electrode layer in the projection plane and the orthographic projection of the edge contour of the ceramic dielectric layer in the projection plane have an overlapped part; the orthographic projection of the first negative electrode layer in the projection plane is located in the orthographic projection of the edge contour of the ceramic dielectric layer in the projection plane, and the first negative electrode layer is electrically connected with the through negative electrode. On the premise that the same driving performance is kept, the overall size is remarkably reduced.

Description

Technical Field

[0001] This application relates to the field of piezoelectric actuator technology, and more specifically, to a multilayer piezoelectric actuator and a method for manufacturing a multilayer piezoelectric actuator. Background Technology

[0002] Piezoelectric materials are functional crystalline materials that generate voltage across their opposite ends when subjected to external mechanical pressure, enabling the conversion between mechanical and electrical energy. Piezoelectric ceramics, as typical piezoelectric materials, possess piezoelectricity, dielectricity, and elasticity, and are widely used in underwater acoustic transducers, ultrasonic imaging, sensors, and ceramic transformers due to their excellent energy conversion performance. With the rapid development of electronic information technology and the evolution of electronic products towards integration, thinning, and miniaturization, piezoelectric ceramic components are also gradually developing towards high performance, miniaturization, and multilayering. Among them, multilayer piezoelectric ceramic devices, by stacking multiple piezoelectric layers and electrode layers in a single element, can achieve large displacement and output force at lower driving voltages, thus becoming an important structural form for realizing high-efficiency micro-drives. Multilayer piezoelectric actuators are a key application device based on this multilayer structure principle, widely used in micro-pumps, precision positioning platforms, inkjet printheads, and active vibration control devices. However, current multilayer piezoelectric actuators generally suffer from large size. Summary of the Invention

[0003] The purpose of this application is to provide a multilayer piezoelectric actuator and a method for manufacturing a multilayer piezoelectric actuator, aiming to solve the technical problem of large volume of multilayer piezoelectric actuators in related technologies.

[0004] To achieve the above objectives, the technical solution adopted in this application is as follows: This application provides a stacked piezoelectric actuator, comprising: a piezoelectric actuator body; The piezoelectric drive body includes a piezoelectric ceramic body, a drive unit, a side positive electrode group, and a through negative electrode. The side positive electrode group is provided on the circumferential side of the piezoelectric ceramic body, and the through negative electrode extends in the piezoelectric ceramic body along a first direction, which is the height direction of the stacked piezoelectric drive. The piezoelectric ceramic body includes a plurality of ceramic dielectric layers stacked along a first direction; The driving unit includes a plurality of driving electrode layers stacked along a first direction, with adjacent driving electrode layers separated by at least one ceramic dielectric layer; In the plurality of driving electrode layers, at least one driving electrode layer is a positive electrode layer and at least one driving electrode layer is a first negative electrode layer; The positive electrode layer has an overlapping portion between its orthographic projection in the projection plane and the edge contour of the ceramic dielectric layer in the projection plane, so that the positive electrode layer is electrically connected to the side positive electrode group. The orthogonal projection of the first negative electrode layer in the projection plane is located inside the orthogonal projection of the edge contour of the ceramic dielectric layer in the projection plane, and the first negative electrode layer is electrically connected to the through negative electrode. The projection plane is perpendicular to the first direction.

[0005] In some implementations, the stacked piezoelectric actuator includes a surface insulating layer, with the top and bottom surfaces of the piezoelectric actuator body respectively provided with the surface insulating layer.

[0006] In some implementations, among the multiple driving electrode layers, there are multiple positive electrode layers and multiple first negative electrode layers; Multiple positive electrode layers and multiple first negative electrode layers are alternately stacked along a first direction.

[0007] In some implementations, the through-hole negative electrode also passes through the surface insulating layer.

[0008] In some implementations, the piezoelectric drive body also includes a side negative electrode, which is provided on the peripheral surface of the piezoelectric ceramic body; In the plurality of driving electrode layers, at least one driving electrode layer is a second negative electrode layer, and the second negative electrode layer is electrically connected to the through negative electrode. The second negative electrode layer has an overlapping portion between its orthogonal projection in the projection plane and the orthogonal projection of the edge contour of the ceramic dielectric layer in the projection plane, so that the second negative electrode layer is electrically connected to the side negative electrode.

[0009] In some implementations, among the multiple driving electrode layers, there are multiple positive electrode layers, multiple first negative electrode layers, and multiple second negative electrode layers; Multiple first negative electrode layers and multiple second negative electrode layers are alternately stacked along a first direction, and a positive electrode layer is disposed between adjacent first negative electrode layers and second negative electrode layers.

[0010] In some implementations, two adjacent driving electrode layers are separated by two ceramic dielectric layers.

[0011] This application provides a method for manufacturing a multilayer piezoelectric actuator, which is used to manufacture the multilayer piezoelectric actuator in any of the above implementations; A method for manufacturing a multilayer piezoelectric actuator includes: Prepare piezoelectric ceramic sheets, wherein the ceramic dielectric layer is formed from piezoelectric ceramic sheets; A driving electrode layer is formed on a piezoelectric ceramic sheet using a screen printing process, so that the piezoelectric ceramic sheet and the driving electrode layer together form a dielectric film. Multiple dielectric membranes are stacked together in a predetermined order to form a bar block; The block is subjected to isostatic pressing; The bar blocks that have undergone isostatic pressing are sequentially cut, debinded, and sintered to form a single, integrally molded driver unit. A surface electrode assembly is formed on the surface of the driver unit using a screen printing process. The surface electrode assembly includes a side positive electrode assembly. The through-hole negative electrode includes at least a portion formed by filling the through-hole with conductive material after preparing a through-hole in a piezoelectric ceramic sheet.

[0012] In some implementations, the method for manufacturing a multilayer piezoelectric actuator further includes, prior to forming the driving electrode layer on the piezoelectric ceramic substrate using a screen printing process: A perforation operation is performed on the piezoelectric ceramic sheet to form through holes in the piezoelectric ceramic sheet; The through-hole is filled with conductive material.

[0013] In some implementations, the method for manufacturing a multilayer piezoelectric actuator further includes, prior to forming a surface electrode assembly on the surface of the actuator unit using a screen printing process: Along the height direction of the driver unit, an opening operation is performed on the driver unit to form a through hole on the driver unit, wherein the through hole includes a through hole formed on the piezoelectric ceramic sheet. The through-hole is filled with conductive material.

[0014] The main advantages of the multilayer piezoelectric actuator and its manufacturing method provided in this application are as follows: This application connects the positive electrode group on the side to the edge of the positive electrode layer, and the negative electrode layer is recessed within the edge contour of the ceramic dielectric layer. It also adopts a through-type negative electrode longitudinal lead-out design, which can solve the lead-out redundancy in related technologies, effectively compress the lateral dimension spacing, significantly reduce the overall volume while maintaining the same driving performance, and greatly increase the effective driving area ratio. This can meet the needs of high-performance micro-stacked piezoelectric actuators for applications in extremely small spaces. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of a first type of stacked piezoelectric actuator with 64 drive units provided in the embodiments of this application; Figure 2 yes Figure 1A schematic diagram of the structure of the positive electrode dielectric film in a stacked piezoelectric actuator; Figure 3 yes Figure 1 A schematic diagram of the structure of the dielectric film of the second negative electrode in the stacked piezoelectric actuator; Figure 4 yes Figure 1 A schematic diagram of the structure of the first negative electrode dielectric film in the stacked piezoelectric actuator; Figure 5 yes Figure 1 A schematic diagram of the structure of a ceramic dielectric layer with conductive vias in a multilayer piezoelectric actuator; Figure 6 This is a schematic diagram of the positive electrode dielectric film of a first type of stacked piezoelectric actuator with 49 driving units provided in the embodiments of this application; Figure 7 This is a schematic diagram of the structure of the second negative electrode dielectric film of a first type of stacked piezoelectric actuator with 49 driving units provided in the embodiments of this application; Figure 8 This is a schematic diagram of the structure of the first negative electrode dielectric film of a first type of stacked piezoelectric actuator with 49 driving units provided in the embodiments of this application; Figure 9 This is a flowchart of a method for manufacturing a multilayer piezoelectric actuator provided in an embodiment of this application; Figure 10 This is a schematic diagram of the structure of a second type of stacked piezoelectric actuator with 64 drive units provided in an embodiment of this application; Figure 11 yes Figure 10 A schematic diagram of the structure of the positive electrode dielectric film in a stacked piezoelectric actuator; Figure 12 yes Figure 10 A schematic diagram of the structure of the first negative electrode dielectric film in the stacked piezoelectric actuator; Figure 13 This is a schematic diagram of the positive electrode dielectric film of a second type of stacked piezoelectric actuator with 49 driving units provided in the embodiments of this application; Figure 14 This is a schematic diagram of the structure of the first negative electrode dielectric film of a second type of stacked piezoelectric actuator with 49 driving units provided in the embodiments of this application; Figure 15 This is a flowchart of another method for manufacturing a stacked piezoelectric actuator provided in an embodiment of this application.

[0017] Explanation of key figure labels: 101. Piezoelectric ceramic body; 102. Side positive electrode group; 103. Side positive electrode; 104. Through negative electrode; 105. Positive electrode layer; 106. First negative electrode layer; 108. Driving island; 109. Positive lead; 110. Common island; 111. Negative lead; 112. Surface insulating layer; 113. Top positive electrode group; 114. End face positive electrode; 115. Side negative electrode; 116. Second negative electrode layer; 117. End face negative electrode; 118. Ceramic dielectric layer; 119. Conductive via. Detailed Implementation

[0018] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0019] Combination Figures 1 to 5 As shown, this application embodiment provides a stacked piezoelectric actuator that is an array-integrated stacked piezoelectric actuator. The stacked piezoelectric actuator includes: a piezoelectric driving body; the piezoelectric driving body includes a piezoelectric ceramic body 101, a driving part, a side positive electrode group 102, and a through negative electrode 104. The side positive electrode group 102 is disposed on the circumferential side of the piezoelectric ceramic body 101, and the through negative electrode 104 extends in the piezoelectric ceramic body 101 along a first direction, which is the height direction of the stacked piezoelectric actuator; the piezoelectric ceramic body 101 includes a plurality of ceramic dielectric layers 118 stacked along the first direction; the driving part includes a plurality of driving electrode layers stacked along the first direction, and adjacent driving electrode layers are arranged in a manner that allows for the formation of multiple driving electrode layers. The electrode layers are separated by at least one ceramic dielectric layer 118; among the plurality of driving electrode layers, at least one driving electrode layer is a positive electrode layer 105, and at least one driving electrode layer is a first negative electrode layer 106; the orthogonal projection of the positive electrode layer 105 in the projection plane overlaps with the orthogonal projection of the edge contour of the ceramic dielectric layer 118 in the projection plane, so that the positive electrode layer 105 is electrically connected to the side positive electrode group 102; the orthogonal projection of the first negative electrode layer 106 in the projection plane is located inside the orthogonal projection of the edge contour of the ceramic dielectric layer 118 in the projection plane, and the first negative electrode layer 106 is electrically connected to the through negative electrode 104; the projection plane is perpendicular to the first direction.

[0020] The stacked piezoelectric actuator provided in this application embodiment is connected to the edge of the positive electrode layer 105 via the side positive electrode group 102. The negative electrode layer is recessed within the edge contour of the ceramic dielectric layer 118. It adopts a longitudinal lead-out design of the through negative electrode 104 and an asymmetric electrode lead-out design between the side positive electrode group 102 and the through negative electrode 104. This can solve the lead-out redundancy in related technologies, reduce the number of negative electrodes exposed on the surface of the stacked piezoelectric actuator, effectively compress the lateral dimension spacing, significantly reduce the overall volume while maintaining the same driving performance, and greatly increase the effective driving area ratio. This can meet the needs of high-performance micro stacked piezoelectric actuators for applications with extremely small spaces.

[0021] For ease of explanation, the height direction of the stacked piezoelectric actuator is defined as the ZZ direction; the height direction of the piezoelectric ceramic body 101 is parallel to the ZZ direction.

[0022] In some embodiments, the piezoelectric ceramic body 101 is cuboid in shape and has six faces. The circumferential faces of the piezoelectric ceramic body 101 are called side faces, the upper face is called the top face, and the lower face is called the bottom face. The side positive electrode group 102 includes multiple side positive electrodes 103; the side positive electrode group 102 can be provided on all four sides of the piezoelectric ceramic body 101. This ensures that the positive electrode layer 105 has no blind zone connection; and providing side positive electrode groups 102 on multiple sides can disperse the current path and reduce the possibility of local temperature rise. A through negative electrode 104 is provided in the piezoelectric ceramic body 101.

[0023] In some embodiments, one or more ceramic dielectric layers 118 may be provided between two adjacent driving electrode layers, thereby making the interlayer dielectric thickness adjustable, which allows for flexible design according to the required driving voltage, output displacement, and reliability requirements. When only one ceramic dielectric layer 118 is provided between two adjacent driving electrode layers, a higher electric field strength and faster response can be obtained at a lower voltage; when multiple ceramic dielectric layers 118 are provided between two adjacent driving electrode layers, the electric field and stress can be effectively dispersed, improving dielectric strength and structural stability; for example, two, three, or four ceramic dielectric layers 118 may be provided between two adjacent driving electrode layers.

[0024] See Figure 2As shown, in some embodiments, the positive electrode layer 105 may include a plurality of independent driving islands 108 and a positive electrode lead 109 connected to each positive driving island 108; the first negative electrode layer 106 may include a plurality of common islands 110 and a negative electrode lead 111 connecting the plurality of common islands 110 together. For example, the driving islands 108 may be circular, and the common islands 110 may be circular. The orthographic projection of the positive electrode layer 105 in the projection plane overlaps with the orthographic projection of the edge contour of the ceramic dielectric layer 118 in the projection plane. This overlap is a line segment, thus enabling each driving island 108 in the positive electrode layer 105 to be electrically connected to the side positive electrodes 103 on different sides of the piezoelectric ceramic body 101 via the positive electrode lead 109. The number of driving islands 108 in the positive electrode layer 105 is equal to the number of side positive electrodes 103 on the sides of the piezoelectric ceramic body 101. The common island 110 in the positive electrode layer 105 is electrically connected to the through negative electrode 104 via the negative electrode lead 111. The number of driving islands 108 in the positive electrode layer 105 is equal to the number of common islands 110. Each driving island 108 in the positive electrode layer 105 corresponds to one common island 110. The orthographic projection of a driving island 108 in the positive electrode layer 105 onto the projection plane can coincide with the orthographic projection of the corresponding common island 110 in the positive electrode layer 105 onto the projection plane. This allows each driving island 108 to be controlled independently by voltage, with each island operating independently without interference. The number of driving islands 108 in each positive electrode layer 105 can be 16, 25, 36, 49, 64, 81, or 100. This application does not limit the number of driving islands 108, allowing the multilayer piezoelectric actuator to have a corresponding number of driving units, the number of which is equal to the number of driving islands 108 in each positive electrode layer 105. The position of each driving island 108 on the cross-section (perpendicular to the first direction) of the multilayer piezoelectric actuator corresponds to the position of a driving unit. It should be noted that for a stacked piezoelectric actuator, the number of driving islands 108 in each positive electrode layer 105 is equal.

[0025] In some embodiments, the multilayer piezoelectric actuator includes a surface insulating layer 112. The top and bottom surfaces of the piezoelectric actuator body are respectively provided with the surface insulating layer 112, which isolates external moisture and impurities, preventing leakage and performance degradation. Furthermore, the surface insulating layer 112 also provides mechanical protection during packaging and assembly, preventing interlayer peeling or crack propagation, thereby improving the environmental adaptability and service life of the multilayer piezoelectric actuator. The material of the surface insulating layer 112 can be the same as the material of the ceramic dielectric layer 118.

[0026] See Figure 1As shown, in some embodiments, the multilayer piezoelectric actuator further includes a top positive electrode group 113 and a bottom positive electrode group. The top positive electrode group 113 includes a plurality of end-face positive electrodes 114; the bottom positive electrode group includes a plurality of end-face positive electrodes 114. The number of end-face positive electrodes 114 in the top positive electrode group 113 is equal to the number of end-face positive electrodes 114 in the bottom positive electrode group, and is equal to the number of driving islands 108 in each positive electrode layer 105. The outer surface of the surface insulating layer 112 on the top surface of the piezoelectric actuator body is the top surface of the multilayer piezoelectric actuator, and the outer surface of the surface insulating layer 112 on the bottom surface of the piezoelectric actuator body is the bottom surface of the multilayer piezoelectric actuator. The top positive electrode group 113 is located on the top surface of the stacked piezoelectric actuator, and the bottom positive electrode group is located on the bottom surface of the stacked piezoelectric actuator; the end positive electrode 114 is located on the outer surface of the surface insulating layer 112 and is electrically connected to the corresponding side positive electrode 103, so as to realize the electrical connection between the stacked piezoelectric actuator and other components through the end positive electrode 114.

[0027] See Figure 1 As shown, in some embodiments, the piezoelectric drive body further includes a side negative electrode 115, which is disposed on the peripheral surface of the piezoelectric ceramic body 101. Among the multiple drive electrode layers, at least one drive electrode layer is a second negative electrode layer 116, which is electrically connected to the through negative electrode 104. The orthographic projection of the second negative electrode layer 116 in the projection plane overlaps with the orthographic projection of the edge contour of the ceramic dielectric layer 118 in the projection plane, so that the second negative electrode layer 116 is electrically connected to the side negative electrode 115. This allows for the unified lead-out of multiple first negative electrode layers 106 and second negative electrode layers 116, simplifying the external negative electrode structure, reducing resistance loss, and improving the uniformity of the driving electric field distribution and device reliability. For example, the number of side negative electrodes 115 can be one; the second negative electrode layer 116 can include multiple common islands 110 and negative electrode leads 111 connecting the multiple common islands 110 together. The orthographic projection of the second negative electrode layer 116 in the projection plane overlaps with the orthographic projection of the edge contour of the ceramic dielectric layer 118 in the projection plane. Specifically, the orthographic projection of the negative electrode lead 111 overlaps with the orthographic projection of the edge contour of the ceramic dielectric layer 118 in the projection plane. This overlapping portion is a line segment, thus enabling the common island 110 in the second negative electrode layer 116 to be electrically connected to the side negative electrode 115 on the side of the piezoelectric ceramic body 101 via the negative electrode lead 111. It is understood that the number of side negative electrodes 115 can be multiple, such as two, three, or four, depending on the specific requirements.

[0028] See Figure 1As shown, in some embodiments, the through negative electrode 104 may not penetrate the surface insulating layer 112; the through negative electrode 104 is used to electrically connect the plurality of first negative electrode layers 106 and the plurality of second negative electrode layers 116, thus realizing the electrical connection between the first negative electrode layer 106 and the side negative electrode 115. It is understood that in some other possible embodiments, when at least one of the plurality of driving electrode layers is a second negative electrode layer 116, the through negative electrode 104 may also penetrate the surface insulating layer 112.

[0029] In some embodiments, the multilayer piezoelectric actuator further includes a facet negative electrode 117; the top and bottom surfaces of the multilayer piezoelectric actuator each have facet negative electrodes 117, and are electrically connected to side negative electrodes 115, respectively. Exemplarily, the facet negative electrode 117 is located on the outer surface of the surface insulating layer 112 to facilitate electrical connection between the multilayer piezoelectric actuator and other components via the facet negative electrode 117.

[0030] In some embodiments, among the plurality of driving electrode layers, there are multiple positive electrode layers 105, multiple first negative electrode layers 106, and multiple second negative electrode layers 116; the plurality of first negative electrode layers 106 and the plurality of second negative electrode layers 116 are alternately stacked along a first direction, and a positive electrode layer 105 is disposed between adjacent first negative electrode layers 106 and second negative electrode layers 116. This can improve the electric field distribution characteristics and enhance the linearity of the driving response and the output stability. For example, among the plurality of driving electrode layers, a portion of the driving electrode layers may be positive electrode layers 105, a portion of the driving electrode layers may be first negative electrode layers 106, and the remaining portion of the driving electrode layers may be second negative electrode layers 116, that is, the plurality of driving electrode layers includes positive electrode layers 105, first negative electrode layers 106, and second negative electrode layers 116.

[0031] In some embodiments, two adjacent driving electrode layers are separated by two ceramic dielectric layers 118. Exemplarily, the piezoelectric driving body includes a plurality of driving groups stacked along a first direction. Each driving group includes, sequentially stacked along the first direction, a positive electrode layer 105, two ceramic dielectric layers 118, a second negative electrode layer 116, two ceramic dielectric layers 118, a first negative electrode layer 106, and two ceramic dielectric layers 118. The plurality of driving groups are repeatedly stacked along the first direction to form the piezoelectric driving body.

[0032] See Figures 1 to 5 As shown, the stacked piezoelectric actuator has 64 drive units; see also Figures 6 to 8 As shown, the stacked piezoelectric actuator has 49 drive units, which is used in manufacturing... Figures 6 to 8 The corresponding multilayer piezoelectric actuator also has a ceramic dielectric layer with conductive vias; thus Figures 1 to 5 ,or Figures 6 to 8 In the corresponding multilayer piezoelectric actuator, two adjacent driving electrode layers are separated by two ceramic dielectric layers 118.

[0033] It should be noted that in some other possible embodiments, when the multiple driving electrode layers include a positive electrode layer 105, a first negative electrode layer 106, and a second negative electrode layer 116, adjacent driving electrode layers can also be separated by a ceramic dielectric layer 118. The piezoelectric driving body may include: multiple driving groups stacked along a first direction, each driving group including: a positive electrode layer 105, a ceramic dielectric layer 118, a second negative electrode layer 116, a ceramic dielectric layer 118, a first negative electrode layer 106, and a ceramic dielectric layer 118 stacked sequentially along the first direction; the multiple driving groups are repeatedly stacked along the first direction to form the piezoelectric driving body.

[0034] Combination Figures 10 to 12 As shown, in some embodiments, among the multiple driving electrode layers, there are multiple positive electrode layers 105 and multiple first negative electrode layers 106; the multiple positive electrode layers 105 and the multiple first negative electrode layers 106 are alternately stacked along a first direction. This alternating stacking structure can improve the driving output efficiency and displacement linearity. For example, in the multiple driving electrode layers, a portion of the driving electrode layers may be positive electrode layers 105, and the remaining portion may all be first negative electrode layers 106; that is, the multiple driving electrode layers include only positive electrode layers 105 and first negative electrode layers 106. The piezoelectric driving body includes multiple driving groups stacked along a first direction, each driving group including, in sequence along the first direction: a positive electrode layer 105, a ceramic dielectric layer 118, a first negative electrode layer 106, and a ceramic dielectric layer 118. The multiple driving groups are repeatedly stacked along the first direction to form the piezoelectric driving body.

[0035] See Figures 10 to 12 As shown, the stacked piezoelectric actuator has 64 drive units; see also Figures 13 to 14 As shown, the stacked piezoelectric actuator has 49 drive units; thus Figures 10 to 13 ,or Figures 13 to 14 In the corresponding multilayer piezoelectric actuator, two adjacent driving electrode layers are separated by a ceramic dielectric layer 118.

[0036] See Figure 10As shown, in some embodiments, the through-negative electrode 104 also penetrates the surface insulating layer 112, so that both ends of the through-negative electrode 104 can be exposed on the surface of the stacked piezoelectric actuator, so as to facilitate the control of different drive islands 108 using the positive electrode group and the through-negative electrode 104. For example, when the multiple drive electrode layers consist only of the positive electrode layer 105 and the first negative electrode layer 106, the through-negative electrode 104 can penetrate the surface insulating layer 112.

[0037] This application also provides a method for manufacturing a multilayer piezoelectric actuator, which is used to manufacture an array-type multilayer piezoelectric actuator as provided in any of the above embodiments; the multilayer piezoelectric actuator manufacturing method has the same technical effects as the multilayer piezoelectric actuator provided in the foregoing embodiments, and will not be repeated here.

[0038] See Figure 9 As shown in the embodiments of this application, the method for manufacturing a multilayer piezoelectric actuator may include at least some or all of the following steps.

[0039] Step S10: Prepare piezoelectric green ceramic sheets, wherein the ceramic dielectric layer 118 is formed from piezoelectric green ceramic sheets. Exemplarily, piezoelectric ceramic powder, binder, solvent, and additives are mixed together in a preset ratio and ball-milled or sand-milled for a set time to form a uniform and stable ceramic slurry. The ceramic slurry is then used to prepare a green ceramic tape with a set thickness using a casting machine. The thickness of the green ceramic tape can be 5 μm-60 μm, for example, 5 μm, 10 μm, 20 μm, or 50 μm. The rolled green ceramic tape is then cut to a set size to obtain piezoelectric green ceramic sheets.

[0040] Step S20: A driving electrode layer is formed on a piezoelectric green ceramic sheet using a screen printing process, so that the piezoelectric green ceramic sheet and the driving electrode layer together form a dielectric film. For example, electrode paste can be printed onto the green ceramic sheet using a screen printing process, and after drying, a dielectric film with a defect-free appearance and uniform thickness is obtained. The components in the electrode paste include at least one of silver, silver palladium, and nickel. Specifically, the positive electrode layer 105 and the piezoelectric green ceramic sheet together form a positive electrode dielectric film, the first negative electrode layer 106 and the piezoelectric green ceramic sheet together form a first negative electrode dielectric film, and the second negative electrode layer 116 and the piezoelectric green ceramic sheet together form a second negative electrode dielectric film.

[0041] Step S30: Stack multiple dielectric membranes together in a preset order to form a block.

[0042] Step S40: Perform isostatic pressing on the bar block. For example, isostatic pressing can be performed by uniformly pressing the bar block with hydrostatic water at a uniform temperature, so that the dielectric membranes in the bar block are tightly bonded together to improve the density of the sintered ceramic body.

[0043] Step S50: The bar block, after isostatic pressing, is sequentially cut, debinded, and sintered to form a single-unit actuator. For example, the bar block is first cut laterally and longitudinally to create completely separate, single-unit array-like actuators. Then, a set number of individual actuators are placed in a sagger and placed in a debinding furnace for debinding and sintering according to a set temperature gradient.

[0044] Step S60: A surface electrode assembly is formed on the surface of the driver unit using a screen printing process. The surface electrode assembly includes a side positive electrode assembly 102. For example, after sintering the driver unit, it can be further ground, and then silver paste or silver-palladium paste can be printed on the side of the driver unit using a screen printing process to form side positive electrodes 103, and printed on the top and bottom surfaces to form end positive electrodes 114. Then it is dried to connect all the positive electrode layers 105 inside the driver unit.

[0045] Step S70: Place the driver unit into the polarization device, apply polarization voltage to the positive and negative poles to polarize the driver unit, and obtain an array-integrated stacked piezoelectric driver.

[0046] In the method for manufacturing a multilayer piezoelectric actuator, the through negative electrode 104 includes at least a portion formed by filling the through hole with a conductive material after preparing a through hole in a piezoelectric ceramic sheet; for example, the components in the conductive material include at least one of silver, silver palladium and nickel.

[0047] See Figure 9 As shown, in some embodiments, before forming the driving electrode layer on the piezoelectric ceramic sheet using a screen printing process, i.e., before step S20 and after step S10, the method for manufacturing the stacked piezoelectric actuator further includes: Step S11: Perform an opening operation on the piezoelectric ceramic sheet to form through holes in the piezoelectric ceramic sheet. For example, through holes of a predetermined diameter can be created on the piezoelectric ceramic sheet by mechanical punching or laser drilling. Step S12: Fill the through-holes with conductive material. For example, a screen printing process can be used to fill the through-holes with conductive material, followed by drying. The conductive material includes at least one of silver, silver-palladium, and nickel. The through-holes filled with conductive material are thus called conductive through-holes 119. Subsequent dielectric films also have conductive through-holes 119, and these through-holes 119 are electrically connected to the first negative electrode layer 106 in the first negative electrode dielectric film and to the second negative electrode layer 116 in the second negative electrode dielectric film.

[0048] See Figure 9As shown, in some embodiments, for step S30, the method of stacking multiple dielectric films together in a preset order includes: Multiple dielectric films and piezoelectric ceramic sheets with conductive vias 119 (without a driving electrode layer) are stacked together in a preset order. The preset order can be multiple stacked groups stacked sequentially. The stacking order in each stacked group is: one layer of positive electrode dielectric film, one layer of piezoelectric ceramic sheet with conductive vias 119, one layer of second negative electrode dielectric film, one layer of piezoelectric ceramic sheet with conductive vias 119, one layer of first negative electrode dielectric film, and one layer of piezoelectric ceramic sheet with conductive vias 119. This achieves the separation of two adjacent driving electrode layers by two ceramic dielectric layers 118 as in the aforementioned embodiment. It is understood that during stacking, multiple blank piezoelectric ceramic sheets without holes can be stacked on the top and bottom surfaces of the block to form a surface insulating layer 112. After implementing step S30, multiple conductive vias 119 are connected in series to form a through negative electrode 104.

[0049] See Figure 9 As shown, in some embodiments, the method for forming a surface electrode assembly on the surface of the driver unit using a screen printing process in step S60 further includes: Silver paste or silver-palladium paste is printed on the side of the driver unit using a screen printing process to form a side negative electrode 115, and printed on the top and bottom surfaces to form an end negative electrode 117, so as to connect all the negative electrode layers inside the driver unit.

[0050] This way Figure 9 The manufacturing process shown, and the method for manufacturing multilayer piezoelectric actuators, can be used to manufacture... Figures 1 to 8 The stacked piezoelectric actuator shown.

[0051] See Figure 15 As shown, in some other embodiments, for step S30, the method of stacking multiple dielectric films together in a preset order includes: Multiple dielectric films are stacked together in a preset order; the preset order can be multiple stacked groups stacked sequentially; the stacking order in each stacked group is: one layer of positive electrode dielectric film, one layer of first negative electrode dielectric film. This allows adjacent driving electrode layers in the aforementioned embodiment to be separated by a ceramic dielectric layer 118. It is understood that during stacking, multiple unperforated blank piezoelectric ceramic sheets can be stacked on the top and bottom surfaces of the block to form a surface insulating layer 112.

[0052] See Figure 15As shown, in some other embodiments, before forming the surface electrode assembly on the surface of the driver unit using a screen printing process, i.e., before step S60 and after step 50, the method for manufacturing the multilayer piezoelectric driver further includes: Step S51: Along the height direction of the driver unit, perform an opening operation on the driver unit to form a through hole, wherein the through hole includes a through hole formed on the piezoelectric ceramic sheet. For example, a through hole with a set diameter can be made on the driver unit by mechanical punching or laser drilling, wherein a through hole is also formed on each piezoelectric ceramic sheet.

[0053] Step S52: Fill the through hole with conductive material. Fill the through hole with conductive material and then dry it to form a through electrode. The through electrode passes through the surface insulating layer 112, so that both ends of the through electrode are exposed.

[0054] This way Figure 15 The manufacturing process shown, and the method for manufacturing multilayer piezoelectric actuators, can be used to manufacture... Figures 10 to 14 The stacked piezoelectric actuator shown.

[0055] In summary, the array-integrated stacked piezoelectric actuator provided in this application embodiment achieves a compact structure design by integrating multiple stacked piezoelectric driving units into the same blank and using a through electrode to connect the internal negative electrode layer. Multiple negative electrode layers are concentrated inside the blank and led out by a single electrode, significantly reducing the number of external electrodes. Under the same array quantity, this effectively reduces the overall volume, improves assembly density, and enhances design flexibility.

[0056] Furthermore, each drive unit is an independent discrete unit, which can be driven and controlled by applying voltage separately. The units are independent of each other and do not interfere with each other, resulting in high control precision. After polarization treatment, the driver can generate displacement by applying a driving voltage between the positive and negative electrodes. The output displacement is approximately linearly related to the applied voltage, enabling micro- and nano-level precision displacement control.

[0057] Furthermore, the internal through-hole design effectively reduces the number of side electrodes, lowering the design complexity of multi-array piezoelectric ceramic actuators. By embedding the first negative electrode layer 106 inside the piezoelectric ceramic body 101, the overall insulation performance and reliability are improved, and the impact of humidity on electrode performance is reduced. This design allows for the arrangement of more array units under the same electrical performance conditions, making it suitable for high-density structural schemes with multiple arrays (such as 64 arrays, 81 arrays, 100 arrays, and above).

[0058] This integrated array of stacked piezoelectric actuators boasts advantages such as compact structure, small size, high integration, and high control precision. It enables high-precision, multi-degree-of-freedom, and fast-response drive and control, making it suitable for applications such as deformable mirror control, phased array antennas, and fiber optic modulation in precision optics and adaptive systems; symmetrical drive motors, endoscopes, and micromanipulation in medical robots and minimally invasive surgical instruments; high-load precision platforms and multi-axis collaborative control in industrial automation and nano-positioning; and railway rail defect detection and structural health monitoring in non-destructive testing and sensor networks.

[0059] It should be understood that the "parallel" or "perpendicular" described in the embodiments of this application can be understood as "approximately parallel" or "approximately perpendicular".

[0060] It should also be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Features specified as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0061] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature and the second feature are in direct contact, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0062] It should also be understood that the terms “length,” “width,” “up,” “down,” “front,” “back,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship (if any) based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0063] In the description of this application, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A laminated piezoelectric actuator, characterized by, include: Piezoelectric drive unit; The piezoelectric drive body includes a piezoelectric ceramic body, a drive unit, a side positive electrode group, and a through negative electrode. The side positive electrode group is disposed on the circumferential side of the piezoelectric ceramic body, and the through negative electrode extends in the piezoelectric ceramic body along a first direction, which is the height direction of the stacked piezoelectric drive. The piezoelectric ceramic body includes a plurality of ceramic dielectric layers stacked along the first direction; The driving unit includes a plurality of driving electrode layers stacked along the first direction, and two adjacent driving electrode layers are separated by at least one ceramic dielectric layer; In the plurality of driving electrode layers, at least one driving electrode layer is a positive electrode layer, and at least one driving electrode layer is a first negative electrode layer; The positive electrode layer has an overlapping portion between its orthographic projection in the projection plane and the edge contour of the ceramic dielectric layer in the projection plane, so that the positive electrode layer is electrically connected to the side positive electrode group. The orthogonal projection of the first negative electrode layer in the projection plane is located inside the orthogonal projection of the edge contour of the ceramic dielectric layer in the projection plane, and the first negative electrode layer is electrically connected to the through negative electrode. The projection plane is perpendicular to the first direction.

2. The laminated piezoelectric actuator of claim 1, wherein, The stacked piezoelectric actuator includes a surface insulating layer, and the surface insulating layer is respectively disposed on the top and bottom surfaces of the piezoelectric actuator body.

3. The laminated piezoelectric actuator of claim 2, wherein In the plurality of driving electrode layers, there are multiple positive electrode layers and multiple first negative electrode layers; The plurality of positive electrode layers and the plurality of first negative electrode layers are alternately stacked along the first direction.

4. The laminated piezoelectric actuator of claim 3, wherein, The through negative electrode also penetrates the surface insulating layer.

5. The laminated piezoelectric actuator of claim 2, wherein, The piezoelectric drive body also includes a side negative electrode, which is disposed on the peripheral surface of the piezoelectric ceramic body. In the plurality of driving electrode layers, at least one driving electrode layer is a second negative electrode layer, and the second negative electrode layer is electrically connected to the through negative electrode. The second negative electrode layer has an overlapping portion between its orthogonal projection in the projection plane and the edge contour of the ceramic dielectric layer in the projection plane, so that the second negative electrode layer is electrically connected to the side negative electrode.

6. The laminated piezoelectric actuator of claim 5, wherein, In the plurality of driving electrode layers, there are multiple positive electrode layers, multiple first negative electrode layers, and multiple second negative electrode layers; Multiple first negative electrode layers and multiple second negative electrode layers are alternately stacked along the first direction, and a positive electrode layer is disposed between adjacent first negative electrode layers and second negative electrode layers.

7. The laminated piezoelectric actuator of claim 5 or 6, wherein, The two adjacent driving electrode layers are separated by two ceramic dielectric layers.

8. A method of manufacturing a laminated piezoelectric actuator, characterized by, The method for manufacturing the multilayer piezoelectric actuator is used to manufacture the multilayer piezoelectric actuator as described in any one of claims 1-7; The method for manufacturing the stacked piezoelectric actuator includes: Prepare a piezoelectric ceramic sheet, wherein the ceramic dielectric layer is formed from the piezoelectric ceramic sheet; A driving electrode layer is formed on the piezoelectric ceramic sheet using a screen printing process, so that the piezoelectric ceramic sheet and the driving electrode layer together form a dielectric film. Stacking a plurality of the medium films together in a preset order to form a green compact; Performing isostatic pressing on the green compact; Performing cutting operation, glue removal operation and sintering operation on the green compact subjected to the isostatic pressing in sequence to form an integrally formed driver monomer; Forming a surface electrode group on the surface of the driver monomer by using a screen printing process, the surface electrode group including a side positive electrode group; The through negative electrode at least includes a part formed by filling a conductive material in a through hole after the through hole is prepared on the piezoelectric green sheet.

9. The method of claim 8, wherein the piezoelectric material is poled in the Before the forming of the driving electrode layer on the piezoelectric green sheet by using the screen printing process, the laminated piezoelectric driver manufacturing method further includes: ​ Performing a hole opening operation on the piezoelectric green sheet to form a through hole on the piezoelectric green sheet; Filling a conductive material in the through hole.

10. The method of claim 8, wherein the piezoelectric driver is a multilayer piezoelectric driver. Before the forming of the surface electrode group on the surface of the driver monomer by using the screen printing process, the laminated piezoelectric driver manufacturing method further includes: Performing a hole opening operation on the driver monomer in a height direction of the driver monomer to form a through hole on the driver monomer, wherein the through hole includes the through hole formed on the piezoelectric green sheet; Filling a conductive material in the through hole.

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