Liquid driving device, manufacturing method and microdroplet jetting device

Abstract

The invention discloses a liquid driving device, a manufacturing method and a micro-droplet jetting device.The liquid driving device comprises an isolation layer, a negative electrode layer, a piezoelectric ceramic layer and a positive electrode layer which are arranged in a stacked mode, the side face, away from the negative electrode layer, of the isolation layer serves as the inner wall of a liquid cavity, the isolation layer is a ceramic layer, and the piezoelectric ceramic layer serves as the inner wall of the liquid cavity; in the negative electrode layer and the positive electrode layer, at least one electrode layer comprises a plurality of independently controlled electrodes, and the plurality of independently controlled electrodes, the other electrode layer and the piezoelectric ceramic layer form a plurality of independent piezoelectric driving units. The isolating layer and the piezoelectric ceramic layer in the liquid driving device provided by the invention can be formed through tape casting, and a plurality of piezoelectric layers of the piezoelectric driving units can be formed on one piezoelectric ceramic layer, which is equivalent to that the piezoelectric layers of the piezoelectric driving units can be formed through one-time tape casting, so that the liquid driving device has the advantages that the piezoelectric layers of the piezoelectric driving units can be formed through one-time tape casting; the liquid driving device provided by the invention is simple in structure, simple in manufacturing process and capable of saving working procedures.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of micro-droplet ejection, in particular to a liquid driving device and manufacturing method, and a micro-droplet ejection device. BACKGROUND

[0002] Micro-droplet ejection devices, such as functional coating spray devices, 3D printing devices, nano-silver printing devices, and ink printing heads, all use piezoelectric materials to generate deformation under high voltage to press the liquid and thus eject it. The existing micro-droplet ejection devices have complex manufacturing methods and processes for driving the liquid ejection or dripping. Therefore, there is an urgent need for a new solution to solve the above problems. SUMMARY

[0003] The present application aims to provide a liquid driving device and manufacturing method, and a micro-droplet ejection device to solve the problems existing in the prior art and simplify the structure and manufacturing process.

[0004] To achieve the above-mentioned purpose, the present application provides the following solutions.

[0005] The present application provides a liquid driving device, comprising: an isolation layer, a negative electrode layer, a piezoelectric ceramic layer, and a positive electrode layer which are stacked, a side of the isolation layer away from the negative electrode layer serving as an inner wall of a liquid cavity, the isolation layer being a ceramic layer, at least one of the negative electrode layer and the positive electrode layer comprising a plurality of independently controlled electrodes, the plurality of independently controlled electrodes, the other electrode layer, and the piezoelectric ceramic layer forming a plurality of independent piezoelectric driving units.

[0006] Preferably, the negative electrode layer is a common electrode, and the positive electrode layer comprises a plurality of independently controlled positive electrodes.

[0007] Preferably, the piezoelectric ceramic layer between adjacent piezoelectric driving units is provided with a weakening structure, and the weakening structure can weaken the rigidity of the piezoelectric ceramic layer.

[0008] Preferably, the weakening structure is a through hole or a groove formed on the piezoelectric ceramic layer.

[0009] Preferably, the combination layer composed of the piezoelectric ceramic layer and the positive electrode layer is provided with one or more layers.

[0010] Preferably, the isolation layer and the piezoelectric ceramic layer are sintered after flow casting, and before sintering, the negative electrode layer is screen printed on the isolation layer, and the positive electrode layer is screen printed on the piezoelectric ceramic layer.

[0011] The application also provides a micro-droplet ejection device, comprising a plurality of liquid cavities and the liquid driving device as described above, the bottom of the liquid cavity is configured with a nozzle, and the top is configured with an opening, the openings of all the liquid cavities are located on the same plane, and the liquid driving device covers the openings and seals all the openings.

[0012] The application also provides a manufacturing method of the liquid driving device as described above, comprising:

[0013] A green body of the isolation layer is manufactured by using a flow casting process;

[0014] A negative electrode layer is manufactured on the top surface of the green body of the isolation layer by using a silk screen process;

[0015] A green body of the piezoelectric ceramic layer is manufactured on the negative electrode layer by using a flow casting process;

[0016] A positive electrode layer is manufactured on the green body of the piezoelectric ceramic layer by using a silk screen process;

[0017] Sintering forming.

[0018] Preferably, the back surface of the isolation layer is ground so that the flatness is within 1 micrometer.

[0019] Preferably, the negative electrode layer and the positive electrode layer are both silk screened by using conductive metal materials;

[0020] The piezoelectric ceramic layer is provided with grooves or through holes, and when the piezoelectric ceramic layer is cast, the piezoelectric ceramic layer is filled with resin materials by using a silk screen machine, and the resin materials are removed at high temperature during sintering forming.

[0021] The application has the following technical effects compared with the prior art:

[0022] The isolation layer and the piezoelectric ceramic layer in the liquid driving device provided by the application can be formed by flow casting, a plurality of piezoelectric driving unit piezoelectric layers can be formed on one piezoelectric ceramic layer, and the piezoelectric layers of a plurality of piezoelectric driving units can be formed by once flow casting, so that the liquid driving device provided by the application has simple structure and simple manufacturing process, and the process is saved. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0024] Figure 1Part structure schematic diagram of liquid driving device provided by the embodiment of the present application;

[0025] Figure 2 Part structure schematic diagram of liquid driving device provided by the embodiment of the present application; Figure 1 Top view of the liquid driving device in the embodiment of the present application;

[0026] Figure 3 Part structure schematic diagram of liquid driving device provided by the embodiment of the present application; Figure 2 Sectional view of A-A direction of the liquid driving device in the embodiment of the present application;

[0027] Figure 4 Part structure schematic diagram of liquid driving device provided by the embodiment of the present application; Figure 1 Part structure schematic diagram of liquid driving device provided by the embodiment of the present application;

[0028] Figure 5 Part structure schematic diagram of liquid driving device provided by the embodiment of the present application; Figure 1 Part structure schematic diagram of liquid driving device provided by the embodiment of the present application;

[0029] In the figure: 1-piezoelectric ceramic layer; 2-isolation layer; 3-negative electrode layer; 4-positive electrode layer; 41-positive electrode; 5-groove; 6-nozzle; 7-liquid cavity; 8-liquid cavity isolation structure. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0031] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0032] In the related art, one liquid cavity corresponds to one or several piezoelectric driving units, and the piezoelectric driving unit corresponding to each liquid cavity needs to be separately manufactured and processed and spliced and assembled, which greatly increases the complexity of the process. Based on this, the present application provides the following embodiments to solve the defects.

[0033] The present application provides a liquid driving device suitable for coating spray device, piezoelectric micropump, 3D printing device, nano-silver printing device and ink printing head, etc. Figures 1 to 5As shown, the liquid driving device comprises: an isolation layer 2, a negative electrode layer 3, a piezoelectric ceramic layer 1 and a positive electrode layer 4 which are arranged in a stack, a side of the isolation layer 2 away from the negative electrode layer 3 serving as an inner wall of a liquid cavity, the isolation layer 2 being used for isolating ink and sealing the liquid cavity 7, the isolation layer 2 being a ceramic layer, at least one of the negative electrode layer 3 and the positive electrode layer 4 comprising a plurality of independently controlled electrodes, the electrode layer being the negative electrode layer 3 or the positive electrode layer 4, the plurality of independently controlled electrodes and the other electrode layer and the piezoelectric ceramic layer 1 forming a plurality of independent piezoelectric driving units.

[0034] The isolation layer 2 and the piezoelectric ceramic layer 1 in the liquid driving device provided by the embodiment of the present application can be formed by flow casting, a plurality of piezoelectric layers of piezoelectric driving units can be formed on one piezoelectric ceramic layer 1, which is equivalent to forming the piezoelectric layers of the plurality of piezoelectric driving units by flow casting once, and thus the liquid driving device provided by the present application is simple in structure and simple in manufacturing process, and the process is saved.

[0035] The isolation layer 2 in the embodiment of the present application is used for sealing the liquid cavity and protecting the negative electrode layer 3 from being eroded by the liquid.

[0036] In some embodiments, the material of the isolation layer 2 is preferably the same as that of the piezoelectric ceramic layer 1, so as to maintain the same thermal expansion coefficient.

[0037] In some embodiments, the negative electrode layer 3 is a common electrode, and the positive electrode layer 4 comprises a plurality of independently controlled positive electrodes 41.

[0038] Compared with the scheme in which the negative electrode is also provided as a plurality of independently controlled electrodes, the negative electrode layer 3 is taken as a common electrode in the embodiment, which not only simplifies the control logic during work, but also facilitates the production by silk printing.

[0039] In some embodiments, the positive electrodes 41 are arranged in an array, as shown in the partial structure diagram. Figure 2 Two rows of positive electrodes 41 are provided, and each positive electrode 41 in the two rows of positive electrodes 41 can be arranged in vertical alignment or staggered arrangement.

[0040] In some embodiments, a weakening structure is provided on the piezoelectric ceramic layer 1 between adjacent piezoelectric driving units, and the weakening structure can weaken the rigidity of the piezoelectric ceramic layer 1.

[0041] Specifically, the weakening structure is a through hole or a groove 5 formed on the piezoelectric ceramic layer 1.

[0042] The weakening structure in the embodiment can prevent the action interference between the adjacent piezoelectric driving units, that is, the so-called cross-talk, that is, when one of the two adjacent piezoelectric driving units works, the other unit is also affected, and the other unit is also deformed to a certain extent. The weakening structure is set to physically cut off the hard connection between the two piezoelectric driving units, and the connection between the two piezoelectric driving units is reduced, so that the influence between the two piezoelectric driving units is reduced.

[0043] In some embodiments, the piezoelectric ceramic layer 1 and the positive electrode layer 4 form a combined layer, and one or more layers are provided. When multiple layers are provided, each electrode in each positive electrode layer 4 is arranged in a vertical position with the electrodes of other layers. It can be understood that the electrodes arranged in a vertical position can be controlled synchronously or independently.

[0044] The embodiment can increase the driving amplitude, and the driving amplitude can be adjusted by controlling the number of layers and the working of the electrodes in different layers.

[0045] In some embodiments, the isolation layer 2 and the piezoelectric ceramic layer 1 are sintered after being formed by flow casting. Before sintering, the negative electrode layer 3 is screen printed on the isolation layer 2, and the positive electrode layer 4 is screen printed on the piezoelectric ceramic layer 1.

[0046] The embodiment of the present application also provides a micro-droplet ejection device, which comprises a plurality of liquid cavities 7 and a liquid driving device as described above, the bottom of each liquid cavity 7 is provided with a nozzle 6, and the top of each liquid cavity 7 is provided with an opening, all the openings on the top of the liquid cavities 7 are located on the same plane, and the liquid driving device is arranged on the openings and seals all the openings.

[0047] The liquid cavity 7 is located directly below the positive electrode.

[0048] The embodiment has all the advantages of all the above-mentioned embodiments, and will not be described here.

[0049] The present application also provides a manufacturing method of the liquid driving device as described above, which comprises the following steps.

[0050] A green body of the isolation layer 2 is manufactured by using a flow casting process;

[0051] A negative electrode layer 3 is manufactured on the top surface of the green body of the isolation layer 2 by using a screen printing process;

[0052] A green body of the piezoelectric ceramic layer 1 is manufactured on the negative electrode layer 3 by using a flow casting process;

[0053] A positive electrode layer 4 is manufactured on the green body of the piezoelectric ceramic layer 1 by using a screen printing process;

[0054] Sintering is performed.

[0055] The liquid driving device manufacturing method provided by the embodiment of the application has simple process, high feasibility and high precision, and saves processes.

[0056] In some embodiments, the back of the isolation layer 2 is ground so that the flatness is within 1 micrometer.

[0057] In some embodiments, the negative electrode layer 3 and the positive electrode layer 4 are both screen-printed by conductive metal materials.

[0058] The piezoelectric ceramic layer 1 is provided with grooves 5 or through holes, and when the piezoelectric ceramic layer 1 is cast, the piezoelectric ceramic layer 1 is filled with resin materials by a screen printer, and the resin materials are removed at high temperature when sintering and forming. In addition, the grooves 5 or through holes can also be processed by laser cutting.

[0059] The specific manufacturing scheme is as follows.

[0060] Step one: the isolation layer 2 is first cast by a casting machine, with a thickness of 20 micrometers, and the precision tolerance is controlled within ±0.5 micrometers.

[0061] Step two: the conductive metal material is screen-printed as the negative electrode layer 3, with a thickness of 1 micrometer, and the precision tolerance is controlled within ±0.5 micrometers.

[0062] Step three: the piezoelectric ceramic layer 1 is cast on the negative electrode layer 3, with a thickness of 40 micrometers, and the precision tolerance is controlled within ±0.5 micrometers.

[0063] Step four: the grooves 5 or through holes are filled with resin materials that can be easily removed by a screen printer when casting, and the resin materials are removed at high temperature when sintering and forming.

[0064] Step five: the conductive metal material is printed by a screen printer to form the positive electrode layer 4.

[0065] Step six: sintering and forming.

[0066] Step seven: the bottom isolation layer 2 is ground to remove 15 micrometers, and the flatness is ensured to be within 3 micrometers, which prepares for subsequent bonding on the top opening of the liquid cavity 7.

[0067] The conductive metal material in all the above embodiments of the application can be a material with good conductive performance, such as nickel-palladium or silver.

[0068] The principles and implementation manners of the application are described by specific examples in the application, and the above embodiment is only used to help understand the method and core idea of the application; meanwhile, for those skilled in the art, the specific implementation manners and application range can be changed according to the idea of the application. In conclusion, the content of the specification should not be understood as a limitation of the application.

Claims

1. A liquid-driven device, characterized in that: include: The system comprises a stacked isolation layer, a negative electrode layer, a piezoelectric ceramic layer, and a positive electrode layer. The side of the isolation layer facing away from the negative electrode layer serves as the inner wall of the liquid cavity. The isolation layer is a ceramic layer. At least one of the negative electrode layer and the positive electrode layer includes multiple independently controlled electrodes. The multiple independently controlled electrodes, the other electrode layer, and the piezoelectric ceramic layer form multiple independent piezoelectric drive units.

2. The liquid-driven device according to claim 1, characterized in that: The negative electrode layer is a common electrode, and the positive electrode layer includes multiple independently controlled positive electrodes.

3. The liquid-driven device according to claim 1, characterized in that: A weakening structure is provided on the piezoelectric ceramic layer between adjacent piezoelectric driving units, and the weakening structure can reduce the stiffness of the piezoelectric ceramic layer.

4. The liquid-driven device according to claim 3, characterized in that: The weakening structure is a through hole or groove formed on the piezoelectric ceramic layer.

5. The liquid-driven device according to claim 1, characterized in that: The composite layer consisting of the piezoelectric ceramic layer and the positive electrode layer may have one or more layers.

6. The liquid-driven device according to claim 1, characterized in that: The isolation layer and the piezoelectric ceramic layer are formed by casting and sintering. Before sintering, the negative electrode layer is screen-printed on the isolation layer and the positive electrode layer is screen-printed on the piezoelectric ceramic layer.

7. A microdroplet ejection device, characterized in that: The device includes multiple liquid chambers and a liquid driving device as described in any one of claims 1 to 6. The bottom of each liquid chamber is provided with a nozzle and the top is provided with an opening. All the openings at the top of the liquid chambers are located on the same plane. The liquid driving device covers the openings and closes all the openings.

8. A method for manufacturing a liquid-driven device according to any one of claims 1 to 6, characterized in that: include: The green embryo for the isolation layer is made using a casting process; A negative electrode layer is fabricated on the top surface of the green substrate of the isolation layer using a screen printing process. A green piezoelectric ceramic layer is fabricated on the negative electrode layer using a tape casting process. A positive electrode layer is fabricated on the green piezoelectric ceramic layer using a screen printing process. Sintering and shaping.

9. The method for manufacturing the liquid-driven device according to claim 8, characterized in that: The back side of the isolation layer is ground to make its flatness within 1 micrometer.

10. The method for manufacturing the liquid-driven device according to claim 8, characterized in that: Both the negative electrode layer and the positive electrode layer are formed by screen printing with conductive metal material.

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