Piezoelectric annular stack
By designing a ring-shaped piezoelectric element and connecting multiple layers of through holes, an internal parallel circuit is constructed, which solves the problems of insufficient driving power and electric field concentration in traditional piezoelectric stacks, and realizes a piezoelectric stack with high driving power and high reliability.
Patent Information
- Application Number
- CN202511378055.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-25
- Publication Date
- 2025-11-28
AI Technical Summary
Existing single-layer piezoelectric sheets have insufficient driving force, and traditional parallel piezoelectric sheets with full-surface electrodes have insufficient driving voltage, making it difficult to increase driving power, especially in high-throughput and high-output pressure applications. Furthermore, parallel stacking of full-surface electrodes poses a risk of local leakage and insulation breakdown due to electric field concentration.
The design employs a ring-shaped piezoelectric element, with a through hole in the center of the piezoelectric element. Multiple piezoelectric elements are connected through the hole to form an internal parallel circuit. The ring electrode design avoids electric field concentration, enabling safe operation under low voltage.
It improves the driving power and reliability of piezoelectric stacks, reduces the risk of partial discharge and insulation breakdown, and meets the low voltage and long-term reliability requirements of products such as micropumps and atomizing plates.
Smart Images
Figure CN121038579A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of piezoelectric stack, and discloses a piezoelectric ring stack. BACKGROUND
[0002] The piezoelectric micropump and the piezoelectric atomization sheet are core components in the field of modern precise fluid control and delivery, and are widely used in medical atomization, electronic cigarettes, microfluidic chips, semiconductor cooling, wearable / portable devices, humidifiers and the like. The working principle is to use the inverse piezoelectric effect of the piezoelectric sheet to produce periodic deformation under the action of an alternating electric field, thereby driving the flow of fluid or generating microdroplets.
[0003] At present, the related products on the market mostly use single-layer piezoelectric sheets. Such a single-layer structure has the advantages of simple driving circuit and low cost. However, the deformation and output force of the single-layer piezoelectric sheet are limited, which makes it difficult to further improve the driving power. This becomes a key bottleneck restricting the breakthrough of device performance, especially in applications requiring high throughput, high output pressure or viscous fluid delivery. The driving force of the single-layer piezoelectric sheet is obviously insufficient. In order to improve the driving power, a multi-layer piezoelectric stack solution can be used. The traditional piezoelectric stack is usually formed by stacking multiple piezoelectric sheets in the thickness direction and connecting them through gluing or other methods, and is connected in parallel in terms of electricity.
[0004] The parallel stack with full-surface electrodes in the prior art can make the entire stack work at a low voltage of a single-layer piezoelectric sheet, which meets the basic requirement of low-voltage operation of products such as micropumps and atomization sheets. However, the full-surface electrodes can cause the edge electric field of the piezoelectric sheet to be extremely concentrated, which can easily cause local electric leakage or insulation breakdown. For micropumps and atomization sheets that need to work reliably for a long time and may be in a humid environment, such structure has high risk and short service life, and is difficult to meet the reliability requirements of products.
[0005] In summary, in the field of piezoelectric micropumps and atomization sheets, the existing single-layer ceramic solution has limited power, and the traditional full-electrode parallel stack solution has the risk of uneven electric field breakdown. Therefore, there is an urgent need for a new piezoelectric stack structure in the field. SUMMARY
[0006] The purpose of the present application is to provide a piezoelectric ring stack.
[0007] To achieve the above object, the technical scheme adopted by the present application is as follows: a piezoelectric ring-shaped stack, at least comprising a first piezoelectric sheet and a second piezoelectric sheet, the middle part of the first piezoelectric sheet is provided with a first through hole, the first piezoelectric sheet has a first surface and a second surface, the first surface is simultaneously provided with a first electrode and a second electrode, at least one of the first electrode or the second electrode extends to the second surface through the first through hole, the second piezoelectric sheet has a third surface and a fourth surface, the third surface is attached to the first surface, the third surface is simultaneously provided with a third electrode and a fourth electrode, the third electrode is in conduction with the first electrode, the fourth electrode is in conduction with the second electrode, at least one of the third electrode or the fourth electrode extends to the fourth surface, and at least two opposite electrodes exist among the electrodes extending to the second surface and the fourth surface.
[0008] As a preferred, the first electrode and the second electrode on the first surface are both annular and concentrically arranged, the first electrode is located inside the second electrode, and the areas of the first electrode and the second electrode are equal.
[0009] Further preferably, the first electrode extends to the second surface through the first through hole, the second electrode extends to the second surface through the outside of the first piezoelectric sheet, and the arrangement of the first electrode and the second electrode on the first surface is the same as that on the second surface.
[0010] Further preferably, the middle part of the second piezoelectric sheet is provided with a second through hole, the fourth electrode extends to cover the entire fourth surface through the outside of the second piezoelectric sheet, the arrangement of the third electrode and the fourth electrode on the third surface is the same as that of the first electrode and the second electrode on the first surface; the second piezoelectric sheet is connected with at least one first piezoelectric sheet, the first piezoelectric sheet farthest from the second piezoelectric sheet is further connected with a third piezoelectric sheet through the second surface, the middle part of the third piezoelectric sheet is provided with a third through hole, the third piezoelectric sheet has a fifth surface and a sixth surface, the fifth surface is simultaneously provided with a fifth electrode and a sixth electrode, the fifth electrode extends to cover the entire sixth surface through the third through hole, the arrangement of the fifth electrode and the sixth electrode on the fifth surface is the same as that of the first electrode and the second electrode on the second surface; the polarity of the fourth electrode is opposite to that of the fifth electrode.
[0011] Further preferably, the fourth electrode extends to cover the entire fourth surface through the outside of the second piezoelectric sheet, the third electrode is located in the middle part of the third surface and is circular, the diameter of the third electrode is equal to the outer diameter of the first electrode, and the second piezoelectric sheet is connected with at least one first piezoelectric sheet.
[0012] Further preferably, the first piezoelectric sheet farthest from the second piezoelectric sheet is further connected with a third piezoelectric sheet through the second surface, the middle part of the third piezoelectric sheet is provided with a third through hole, the third piezoelectric sheet has a fifth surface and a sixth surface, the fifth surface has a fifth electrode and a sixth electrode, the fifth electrode extends to cover the entire sixth surface through the third through hole, the fifth electrode is inside the sixth electrode, and the outer diameter of the fifth electrode is equal to the outer diameter of the first electrode; the fourth electrode is opposite to the fifth electrode in polarity.
[0013] Further preferably, the first piezoelectric sheet farthest from the second piezoelectric sheet is further connected with a third piezoelectric sheet through the second surface, the middle part of the third piezoelectric sheet is provided with a third through hole, the third piezoelectric sheet has a fifth surface and a sixth surface, the fifth surface has a fifth electrode and a sixth electrode, the fifth electrode is inside the sixth electrode, and the outer diameter of the fifth electrode is equal to the outer diameter of the first electrode, the fifth electrode extends to the sixth surface through the third through hole, and the sixth electrode extends to the sixth surface through the outside of the third piezoelectric sheet.
[0014] Further preferably, the first electrode extends to cover the entire second surface through the first through hole, and the second electrode is only on the first surface.
[0015] Further preferably, the middle part of the second piezoelectric sheet is provided with a second through hole, the fourth electrode extends to cover the entire fourth surface through the outside of the second piezoelectric sheet, and the arrangement of the third electrode and the fourth electrode on the third surface is the same as the arrangement of the first electrode and the second electrode on the first surface.
[0016] Further preferably, the fourth electrode extends to cover the entire fourth surface through the outside of the second piezoelectric sheet, and the third electrode is circular in the middle of the third surface and has a diameter equal to the outer diameter of the first electrode.
[0017] Compared with the prior art, the application has the following beneficial effects: (1) The first electrode and the second electrode are arranged on the first surface of the first piezoelectric sheet, at least one of the electrodes is introduced to the second surface through the first through hole, the corresponding third electrode and the fourth electrode are arranged on the third surface of the second piezoelectric sheet, and at least one of the electrodes is introduced to the fourth surface through the outside, and a reliable internal parallel circuit is constructed through the structural arrangement, which enables the entire stack to work at low voltage, and meets the basic requirements of micro-pumps, atomization sheets and other products for low voltage and safe operation.
[0018] (2) The piezoelectric ring-shaped stack of the application at least includes a first piezoelectric sheet and a second piezoelectric sheet, the cooperation of the multi-layer piezoelectric sheet makes the total deformation and output force thereof increase with the increase of the number of stacked layers, and the final output power thereof is much higher than that of the existing single-layer structure, thereby solving the problem of small power of the single-layer piezoelectric sheet in the prior art, and enabling the piezoelectric sheet to be more widely applied to multiple fields such as microfluidics, chip cooling, pressurization of wearable / portable devices and the like.
[0019] (3) The stack structure adopted by the application avoids the edge electric field concentration problem caused by the full-surface electrode of the traditional parallel stack, the partitioned electrode design makes the electric field be constrained between the electrode regions, the distribution is more uniform, the risk of partial discharge and insulation breakdown is fundamentally reduced, and the reliability and service life of the product are significantly improved. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 is a first stack three-dimensional structure schematic diagram of the application.
[0021] Figure 2 is an exploded view of the first stack three-dimensional structure of the application, the left column in the figure is a 45° top view, and the right column is a 45° bottom view.
[0022] Figure 3 is a second stack three-dimensional structure schematic diagram of the application.
[0023] Figure 4 is an exploded view of the second stack three-dimensional structure of the application, the left column in the figure is a 45° top view, and the right column is a 45° bottom view.
[0024] Figure 5 is a third stack three-dimensional structure schematic diagram of the application.
[0025] Figure 6 is an exploded view of the third stack three-dimensional structure of the application, the left column in the figure is a 45° top view, and the right column is a 45° bottom view.
[0026] Figure 7 is a fourth stack three-dimensional structure schematic diagram of the application.
[0027] Figure 8 is an exploded view of the fourth stack three-dimensional structure of the application, the left column in the figure is a 45° top view, and the right column is a 45° bottom view.
[0028] Figure 9 is a fifth stack three-dimensional structure schematic diagram of the application.
[0029] Figure 10is the fifth stacked three-dimensional structure explosion view of the present application, the left column in the figure is a 45° top view, and the right column is a 45° bottom view.
[0030] In the figure: 1, first piezoelectric sheet; 11, first surface; 12, second surface; 13, first electrode; 14, second electrode; 15, first through hole; 2, second piezoelectric sheet; 21, third surface; 22, fourth surface; 23, third electrode; 24, fourth electrode; 25, second through hole; 3, third piezoelectric sheet; 31, fifth surface; 32, sixth surface; 33, fifth electrode; 34, sixth electrode; 35, third through hole. DETAILED DESCRIPTION
[0031] Hereinafter, the present application will be further described in conjunction with specific embodiments, and it should be noted that, without conflict, each embodiment described below or each technical feature can be combined with any other embodiment or technical feature to form a new embodiment.
[0032] In the description of the present application, it should be noted that, for orientation words, such as the terms "center", "transverse", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation and positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and cannot be understood as limiting the specific protection scope of the present application.
[0033] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and do not necessarily describe a specific order or sequence.
[0034] The terms "include" and "have" and any variations thereof in the specification and claims of the present application are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to only those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
[0035] A preferred embodiment of the present application is as follows: Figures 1 to 10As shown, a piezoelectric ring-shaped stack includes at least a first piezoelectric sheet 1 and a second piezoelectric sheet 2, the first piezoelectric sheet 1 is provided with a first through hole 15 in the middle, the first piezoelectric sheet 1 has a first surface 11 and a second surface 12, the first surface 11 is provided with a first electrode 13 and a second electrode 14, at least one of the first electrode 13 or the second electrode 14 extends to the second surface 12 through the first through hole 15, the second piezoelectric sheet 2 has a third surface 21 and a fourth surface 22, the third surface 21 is attached to the first surface 11, the third surface 21 is provided with a third electrode 23 and a fourth electrode 24, the third electrode 23 is in conduction with the first electrode 13, the fourth electrode 24 is in conduction with the second electrode 14, at least one of the third electrode 23 or the fourth electrode 24 extends to the fourth surface 22, and at least two opposite electrodes exist among the electrodes extending to the second surface 12 and the fourth surface 22.
[0036] Further, the first electrode 13 and the second electrode 14 on the first surface 11 are both annular and concentrically arranged, the first electrode 13 is located inside the second electrode 14, the areas of the first electrode 13 and the second electrode 14 are equal, and such arrangement ensures that the working areas of the positive and negative electrodes are the same, and can ensure the best piezoelectric performance.
[0037] The first piezoelectric sheet 1 is a ring-shaped piezoelectric sheet, but the shape is not limited, and can be circular, rectangular, triangular, or even irregular, the first electrode 13 and the second electrode 14 are concentrically arranged, that is, the geometric centers of the first electrode 13 and the second electrode 14 coincide, and through the specific arrangement of the present application, the stacking of the piezoelectric sheet can be realized; in addition, for the piezoelectric ring-shaped stack of the present application, it is preferred to stack piezoelectric ceramic sheets, and other materials that meet engineering requirements can also be used, and the present application does not limit the selection of specific materials.
[0038] In addition, it should be noted that there is a significant problem in the prior art in the process of manufacturing a parallel stack using a non-ring-shaped piezoelectric sheet: the polarization direction of the internal electrode of the existing piezoelectric sheet stack needs to be accurately aligned to prevent positive and negative electrodes from being misaligned to cause interlayer short circuit, therefore, the traditional stack is made into a square shape, and the placement direction of each piezoelectric sheet needs to be accurately positioned, which increases the process complexity and cost, and the assembly process is not simple; the present application uses a ring-shaped piezoelectric sheet for parallel stacking, and the electrode is annular, at this time, only the external parts of the piezoelectric sheets need to be aligned during assembly, and the internal electrodes are synchronously aligned, and there is no problem affected by the electrode direction, so there is no need to consider the placement direction of the electrode sheet during assembly, and the process is greatly simplified.
[0039] The present application provides the following five specific stack forms: As Figures 1 to 2As shown, in the first stacking configuration, the first electrode 13 extends to the second surface 12 through the first through hole 15, and the second electrode 14 extends to the second surface 12 through the outer side of the first piezoelectric sheet 1. The arrangement of the first electrode 13 and the second electrode 14 on the first surface 11 is the same as the arrangement of the first electrode 13 and the second electrode 14 on the second surface 12.
[0040] Furthermore, a second through hole 25 is provided in the middle of the second piezoelectric sheet 2, and the fourth electrode 24 extends through the outer side of the second piezoelectric sheet 2 to cover the entire fourth surface 22. The arrangement of the third electrode 23 and the fourth electrode 24 on the third surface 21 is the same as the arrangement of the first electrode 13 and the second electrode 14 on the first surface 11. The second piezoelectric sheet 2 is connected to at least one first piezoelectric sheet 1, and the first piezoelectric sheet 1 furthest from the second piezoelectric sheet 2 is also connected to a third piezoelectric sheet 3 through the second surface 12. A third through hole 35 is provided in the middle of the third piezoelectric sheet 3. The third piezoelectric sheet 3 has a fifth surface 31 and a sixth surface 32. The fifth surface 31 has both a fifth electrode 33 and a sixth electrode 34. The fifth electrode 33 extends through the third through hole 35 to cover the entire sixth surface 32. The arrangement of the fifth electrode 33 and the sixth electrode 34 on the fifth surface 31 is the same as the arrangement of the first electrode 13 and the second electrode 14 on the second surface 12. The polarity of the fourth electrode 24 is opposite to that of the fifth electrode 33.
[0041] like Figures 3 to 4 As shown, in the second stacking configuration, the first electrode 13 extends to the second surface 12 through the first through hole 15, and the second electrode 14 extends to the second surface 12 through the outer side of the first piezoelectric sheet 1. The arrangement of the first electrode 13 and the second electrode 14 on the first surface 11 is the same as the arrangement of the first electrode 13 and the second electrode 14 on the second surface 12.
[0042] The fourth electrode 24 extends through the outer side of the second piezoelectric sheet 2 to cover the entire fourth surface 22. The third electrode 23 is located in the middle of the third surface 21 and is circular, with a diameter equal to the outer diameter of the first electrode 13. The second piezoelectric sheet 2 is connected to at least one first piezoelectric sheet 1. The first piezoelectric sheet 1 furthest from the second piezoelectric sheet 2 is also connected to a third piezoelectric sheet 3 through the second surface 12. A third through hole 35 is provided in the middle of the third piezoelectric sheet 3. The third piezoelectric sheet 3 has a fifth surface 31 and a sixth surface 32. The fifth surface 31 has both a fifth electrode 33 and a sixth electrode 34. The fifth electrode 33 extends through the third through hole 35 to cover the entire sixth surface 32. The fifth electrode 33 is located inside the sixth electrode 34, and its outer diameter is equal to the outer diameter of the first electrode 13. The polarities of the fourth electrode 24 and the fifth electrode 33 are opposite.
[0043] In the two embodiments described above, since the electrodes on the first surface 11 and the second surface 12 are arranged in the same way, multiple first piezoelectric sheets 1 can be stacked according to actual needs. The second piezoelectric sheet 2 and the third piezoelectric sheet 3 serve as the upper and lower end pieces of this piezoelectric stack, and the fourth surface 22 and the sixth surface 32 can serve as external lead connection surfaces, thereby realizing the circuit conduction of this piezoelectric stack.
[0044] like Figures 5 to 6 As shown, in the third stacking configuration, the first electrode 13 extends to the second surface 12 through the first through hole 15, and the second electrode 14 extends to the second surface 12 through the outer side of the first piezoelectric sheet 1. The arrangement of the first electrode 13 and the second electrode 14 on the first surface 11 is the same as the arrangement of the first electrode 13 and the second electrode 14 on the second surface 12.
[0045] The fourth electrode 24 extends through the outer side of the second piezoelectric sheet 2 to cover the entire fourth surface 22. The third electrode 23 is located in the middle of the third surface 21 and is circular, with a diameter equal to the outer diameter of the first electrode 13. The second piezoelectric sheet 2 is connected to at least one first piezoelectric sheet 1. The first piezoelectric sheet 1 furthest from the second piezoelectric sheet 2 is also connected to a third piezoelectric sheet 3 through the second surface 12. A third through hole 35 is provided in the middle of the third piezoelectric sheet 3. The third piezoelectric sheet 3 has a fifth surface 31 and a sixth surface 32. The fifth surface 31 has a fifth electrode 33 and a sixth electrode 34. The fifth electrode 33 is located inside the sixth electrode 34, and its outer diameter is equal to the outer diameter of the first electrode 13. The fifth electrode 33 extends through the third through hole 35 to the sixth surface 32. The sixth electrode 34 extends through the outer side of the third piezoelectric sheet 3 to the sixth surface 32.
[0046] In this embodiment, since the electrodes on the first surface 11 and the second surface 12 are arranged in the same way, multiple first piezoelectric sheets 1 can be stacked according to actual needs. The fifth electrode 33 extends to the sixth surface 32 through the third through hole 35, and the sixth electrode 34 extends to the sixth surface 32 through the outside of the third piezoelectric sheet 3. At this time, the sixth surface 32 has both positive and negative electrodes. Therefore, a single sixth surface 32 can be directly used as the connection surface of external positive and negative leads, thereby realizing the circuit conduction of this piezoelectric stack. Under this scheme, there is no need to consider the influence of the height of the piezoelectric stack on the external leads.
[0047] like Figures 7 to 8 As shown, in the fourth stacking configuration, the first electrode 13 extends through the first through hole 15 to cover the entire second surface 12, the second electrode 14 is located only on the first surface 11, the second piezoelectric sheet 2 has a second through hole 25 in the middle, and the fourth electrode 24 extends through the outer side of the second piezoelectric sheet 2 to cover the entire fourth surface 22. The arrangement of the third electrode 23 and the fourth electrode 24 on the third surface 21 is the same as the arrangement of the first electrode 13 and the second electrode 14 on the first surface 11.
[0048] As Figures 9 to 10 shown, the fifth stacking form, the first electrode 13 extends to cover the entire second surface 12 through the first through hole 15, the second electrode 14 is only located in the first surface 11, the fourth electrode 24 extends to cover the entire fourth surface 22 through the outer side of the second piezoelectric sheet 2, and the third electrode 23 is located in the middle of the third surface 21 and is circular, and the diameter is equal to the outer diameter of the first electrode 13.
[0049] The above two embodiments only need two piezoelectric sheet stacks, and in the last embodiment, since the first piezoelectric sheet 1 has the first through hole 15 and the second piezoelectric sheet 2 does not have the second through hole 25, in order to prevent the piezoelectric sheet from being crushed, the first through hole 15 needs to be reduced to only maintain the size that can pass the conductive paste. The specific size is designed according to the actual situation.
[0050] In the above embodiments, each electrode can be provided on the corresponding piezoelectric sheet in the form of conductive paste coating. If the corresponding electrodes on the upper and lower surfaces of the piezoelectric sheet need to be connected, a local lead coating method or a full coating method on the outer side or the inner side of the through hole can be used. In order to save costs, the local lead coating method is preferred. In addition, it should be noted that the electrodes in the drawings are shown in an exaggerated manner. In practice, the surface of the piezoelectric sheet is flat and has no obvious protrusions and depressions.
[0051] Each piezoelectric sheet in the present application is composed of a substrate and an electrode. The substrate can be made of various materials, such as piezoelectric polymers, specifically polyvinylidene fluoride and its copolymer, such as lead-free piezoelectric ceramics, specifically barium titanate, potassium sodium niobate, sodium bismuth titanate, etc., such as piezoelectric crystals, specifically quartz, lithium niobate, etc., such as composite piezoelectric materials, etc. The piezoelectric stack in the present application is applied to devices such as micropumps and atomization sheets, and needs to balance performance and driving voltage. At this time, piezoelectric ceramics are preferred. In actual application, those skilled in the art can select according to needs. For example, when the piezoelectric stack is applied to wearable devices or situations that require significant bending, polyvinylidene fluoride and its copolymer can be preferred. When the piezoelectric stack is applied to the fields of aerospace, automotive electronics, etc., it may need to be in a complex environment such as high temperature and needs to have high reliability. At this time, high-performance composite materials such as aramid resin-based materials or piezoelectric crystals can be preferred. Some piezoelectric stacks are applied to devices that require outlets or devices that need to comply with environmental regulations. At this time, lead-free piezoelectric ceramics can be preferred. The electrode is formed by sintering after being coated with conductive paste. The conductive paste can be mainly silver paste, copper paste, carbon paste, aluminum paste, etc. When the piezoelectric stack needs stable performance and high conductivity, silver paste can be preferred, but its cost is high. When the piezoelectric stack needs to be more economical, copper paste, nickel paste, etc. can be selected, but they are prone to oxidation and have high process requirements, and their application range is limited.
[0052] In addition, electrodes are coated on the piezoelectric sheet, and two electrodes need to be coated on one surface, for example, the first piezoelectric sheet 1 in the present application, a first electrode 13 and a second electrode 14 need to be coated on the first surface 11, and the physical isolation of the first electrode 13 and the second electrode 14 needs to be ensured. The present application provides two specific implementation modes: first, the area of the two electrodes is set on the substrate of the piezoelectric sheet in advance, and the two areas are separated by a protrusion, and the height of the protrusion is equal to the coating thickness of the electrode. Taking the first surface 11 as an example, the first electrode 13 and the second electrode 14 are both arranged in a ring shape, and the first electrode 13 is located inside the second electrode 14. Therefore, a ring-shaped protrusion can be arranged on the first surface 11. The area inside the ring-shaped protrusion is the area of the first electrode 13, and the area outside the ring-shaped protrusion is the area of the second electrode 14. Since the ring-shaped protrusion is arranged, the conductive paste will not cross the ring-shaped protrusion during electrode coating, thereby achieving the physical isolation of the two electrodes. Second, a high-precision coating process is used, for example, screen printing or precise partition spraying. Taking the first surface 11 as an example, screen printing is used, and the screen is tightly attached to the first surface 11 by precisely manufacturing the hollow pattern of the two electrodes on the screen. The conductive paste is poured on the screen, and the conductive paste is squeezed onto the first surface 11 through the hollow part by using a scraper. The two electrodes are formed at one time, and it can be ensured that the two electrodes will not be in conduction. The precise formation by screen printing in the prior art is a mature technology.
[0053] The piezoelectric sheet in the present application has the following types: The first type of piezoelectric sheet is suitable for the first piezoelectric sheet 1 of the first stacking form, the first piezoelectric sheet 1 of the second stacking form, and the first piezoelectric sheet 1 of the third stacking form. Specifically, the ceramic substrate is in a ring shape, has a through hole in the middle, and the upper and lower surfaces of the ceramic substrate are coated with electrode one and electrode two. The electrode one and the electrode two are in a ring shape and are physically isolated, and the electrode one is located inside the electrode two. The electrode one on the upper and lower surfaces is in conduction through the through hole, and the electrode two on the upper and lower surfaces is in conduction through the outer side of the ceramic substrate. The arrangement mode of the electrode one and the electrode two on the upper surface is the same as that on the lower surface. In order to better the piezoelectric performance, the coating areas of the electrode one and the electrode two on the two surfaces are equal. The through hole and the outer side can be used to conduct the corresponding electrodes on the upper and lower surfaces in a full coating manner, or in a local coating manner. Considering the cost, the local coating is preferred.
[0054] The second type of piezoelectric sheet is suitable for the second piezoelectric sheet 2 in the first stack form and the second piezoelectric sheet 2 in the fourth stack form. Specifically, the ceramic substrate is annular, has a through hole in the middle, and is coated with electrode one and electrode two on one side. The electrode one and the electrode two are annular and physically isolated, and the electrode one is located inside the electrode two. In order to achieve better piezoelectric performance, the coating area of the electrode one and the electrode two on the surface is equal. The other side is coated with electrode two all over. The electrode two on the upper and lower surfaces is conducted through the outer side of the ceramic substrate. The through hole is not coated with conductive paste. The outer side can be fully coated to conduct the electrode two on the upper and lower surfaces, or it can be partially coated. Considering the cost, partial coating is preferred.
[0055] The third type of piezoelectric sheet is suitable for the third piezoelectric sheet 3 in the first stack form, the first piezoelectric sheet 1 in the fourth stack form, and the first piezoelectric sheet 1 in the fifth stack form. Specifically, the ceramic substrate is annular, has a through hole in the middle, and is coated with electrode one and electrode two on one side. The electrode one and the electrode two are annular and physically isolated, and the electrode one is located inside the electrode two. In order to achieve better piezoelectric performance, the coating area of the electrode one and the electrode two on the surface is equal. The other side is coated with electrode one all over. The electrode one on the upper and lower surfaces is conducted through the through hole. The outer side of the ceramic substrate is not coated with conductive paste. The through hole can be fully coated to conduct the electrode two on the upper and lower surfaces, or it can be partially coated. Considering the cost, partial coating is preferred.
[0056] The fourth type of piezoelectric sheet is suitable for the second piezoelectric sheet 2 in the second stack form, the second piezoelectric sheet 2 in the third stack form, and the second piezoelectric sheet 2 in the fifth stack form. Specifically, the ceramic substrate is circular, and is coated with electrode one and electrode two on one side. The electrode one is circular, the electrode two is annular, and the two electrodes are physically isolated. The electrode one is located inside the electrode two. The other side is coated with electrode two all over. The electrode two on the upper and lower surfaces is conducted through the outer side of the ceramic substrate. The outer side can be fully coated to conduct the electrode two on the upper and lower surfaces, or it can be partially coated. Considering the cost, partial coating is preferred.
[0057] The fifth type of piezoelectric sheet is suitable for the third piezoelectric sheet 3 in the second stack form. Specifically, the ceramic substrate is circular, and is coated with electrode one and electrode two on one side. The electrode one is circular, the electrode two is annular, and the two electrodes are physically isolated. The electrode one is located inside the electrode two. The other side is coated with electrode one all over. There is a small hole in the middle of the ceramic substrate, which allows conductive paste to pass through. The electrode one on the upper and lower surfaces is conducted through the small hole. The outer side of the ceramic substrate is not coated with conductive paste. In addition, it should be noted that the small hole in the figure is exaggerated. In actual use, the small hole can be very small, as long as it can connect the electrode one on the upper and lower surfaces.
[0058] The sixth type of piezoelectric sheet is suitable for the third piezoelectric sheet 3 in the third stack form, specifically, the ceramic substrate is circular, one side of the ceramic substrate is coated with electrode one and electrode two, electrode one is circular, electrode two is annular, and the two electrodes are physically isolated, electrode one is located inside electrode two, the other side is also coated with electrode one and electrode two, and the two electrodes are physically isolated, the specific shape and coating area of the electrode one and electrode two on this surface do not affect, this surface is used to connect the positive and negative leads at the same time, for example, in the third piezoelectric sheet 3 in the third stack form, the electrode one and electrode two on this surface are not annular, electrode one is crescent-shaped, electrode two is double-convex lens-shaped, and the coating area of electrode one is larger than that of electrode two. The piezoelectric sheet of this type has a small hole in the middle of the ceramic substrate, which allows the conductive paste to pass through, and the electrode one on the upper and lower surfaces is connected through the small hole. The electrode two on the upper and lower surfaces is connected through the outer side of the ceramic substrate. The outer side can be fully coated to connect the electrode two on the upper and lower surfaces, or it can be partially coated. Considering the cost, partial coating is preferred. In addition, it should be noted that the small hole in the figure is exaggerated for illustration. In practice, the hole diameter can be very small, as long as it can connect the electrode one on the upper and lower surfaces.
[0059] Through reasonable combination of the above six types of piezoelectric sheets, various forms of piezoelectric stacks can be realized, which are not limited to the five stack forms provided in the present application. Those skilled in the art can make reasonable design and adjustment according to actual needs.
[0060] The above describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above embodiments, the above embodiments and descriptions in the specification are only the principles of the present application, and various changes and improvements can be made without departing from the spirit and scope of the present application. These changes and improvements all fall within the scope of the claimed present application. The scope of protection claimed by the present application is defined by the appended claims and their equivalents.
Claims
1. A piezoelectric ring stack, characterized in that, The device includes at least a first piezoelectric sheet and a second piezoelectric sheet. The first piezoelectric sheet has a first through hole in its middle portion. The first piezoelectric sheet has a first surface and a second surface. The first surface has a first electrode and a second electrode. At least one of the first electrode or the second electrode extends to the second surface through the first through hole. The second piezoelectric sheet has a third surface and a fourth surface. The third surface is attached to the first surface. The third surface has a third electrode and a fourth electrode. The third electrode is connected to the first electrode, and the fourth electrode is connected to the second electrode. At least one of the third electrode or the fourth electrode extends to the fourth surface. At least two of the electrodes extending to the second surface and the fourth surface are opposite electrodes.
2. The piezoelectric ring stack as described in claim 1, characterized in that, The first electrode and the second electrode on the first surface are both arranged in a ring and concentrically, with the first electrode located inside the second electrode, and the areas of the first electrode and the second electrode are equal.
3. The piezoelectric ring stack as described in claim 2, characterized in that, The first electrode extends to the second surface through the first through hole, and the second electrode extends to the second surface through the outside of the first piezoelectric sheet. The arrangement of the first electrode and the second electrode on the first surface is the same as the arrangement of the first electrode and the second electrode on the second surface.
4. The piezoelectric ring stack as described in claim 3, characterized in that, The second piezoelectric sheet has a second through hole in its center. The fourth electrode extends through the outer side of the second piezoelectric sheet to cover the entire fourth surface. The arrangement of the third and fourth electrodes on the third surface is the same as the arrangement of the first and second electrodes on the first surface. The second piezoelectric sheet is connected to at least one first piezoelectric sheet. The first piezoelectric sheet furthest from the second piezoelectric sheet is also connected to a third piezoelectric sheet through the second surface. The third piezoelectric sheet has a third through hole in its center. The third piezoelectric sheet has a fifth surface and a sixth surface. The fifth surface has both a fifth electrode and a sixth electrode. The fifth electrode extends through the third through hole to cover the entire sixth surface. The arrangement of the fifth and sixth electrodes on the fifth surface is the same as the arrangement of the first and second electrodes on the second surface. The fourth electrode has opposite polarities to the fifth electrode.
5. A piezoelectric ring stack as described in claim 3, characterized in that, The fourth electrode extends outward from the second piezoelectric sheet to cover the entire fourth surface. The third electrode is located in the middle of the third surface and is circular, with a diameter equal to the outer diameter of the first electrode. The second piezoelectric sheet is connected to at least one of the first piezoelectric sheets.
6. The piezoelectric ring stack as described in claim 5, characterized in that, The first piezoelectric sheet furthest from the second piezoelectric sheet is further connected to a third piezoelectric sheet via the second surface. The third piezoelectric sheet has a third through hole in its center. The third piezoelectric sheet has a fifth surface and a sixth surface. The fifth surface has both a fifth electrode and a sixth electrode. The fifth electrode extends through the third through hole to cover the entire sixth surface. The fifth electrode is located inside the sixth electrode, and its outer diameter is equal to that of the first electrode. The fourth electrode has the opposite polarity to the fifth electrode.
7. A piezoelectric ring stack as described in claim 5, characterized in that, The first piezoelectric sheet furthest from the second piezoelectric sheet is also stacked with a third piezoelectric sheet via the second surface. The third piezoelectric sheet has a third through hole in its middle. The third piezoelectric sheet has a fifth surface and a sixth surface. The fifth surface has a fifth electrode and a sixth electrode. The fifth electrode is located inside the sixth electrode, and its outer diameter is equal to the outer diameter of the first electrode. The fifth electrode extends to the sixth surface through the third through hole, and the sixth electrode extends to the sixth surface through the outside of the third piezoelectric sheet.
8. The piezoelectric ring stack as described in claim 2, characterized in that, The first electrode extends through the first through-hole to cover the entire second surface, while the second electrode is located only on the first surface.
9. A piezoelectric ring stack as described in claim 8, characterized in that, The second piezoelectric sheet has a second through hole in the middle, and the fourth electrode extends through the outside of the second piezoelectric sheet to cover the entire fourth surface. The arrangement of the third electrode and the fourth electrode on the third surface is the same as the arrangement of the first electrode and the second electrode on the first surface.
10. A piezoelectric ring stack as described in claim 8, characterized in that, The fourth electrode extends outward from the outside of the second piezoelectric sheet to cover the entire fourth surface, and the third electrode is located in the middle of the third surface and is circular, with a diameter equal to the outer diameter of the first electrode.