Micro piezoelectric ceramic gas / liquid control device

Abstract

The utility model provides a miniature piezoelectric ceramic gas / liquid control device which comprises a control cavity, piezoelectric ceramic is arranged on one side of the control cavity, the piezoelectric ceramic is multilayer piezoelectric ceramic, each layer of the multilayer piezoelectric ceramic is provided with a first electrode and a second electrode, and the first electrode is electrically communicated with the second electrode of the adjacent layer. By adopting the multilayer piezoelectric ceramic structure, the piezoelectric ceramic driving voltage is effectively reduced, so that the miniature piezoelectric ceramic gas / liquid control device does not need a working voltage of about 180V any more, and can be powered and driven by using a power supply control module with a common safety voltage in electronic equipment such as a mobile phone and the like; and in addition, large deformation quantity is achieved, large flow can be generated, good stability and adaptability are achieved, the production cost is low, and the technology is stable.

Description

TECHNICAL FIELD

[0001] The utility model relates to micro electronic component technology field, concretely is a piezoelectric ceramic fluid control device. BACKGROUND

[0002] Piezoelectric pump is a kind of micro pump manufacturing technology, utilizes the inverse piezoelectric effect of piezoelectric ceramic, makes piezoelectric vibrator produce deformation, and further causes control cavity volume variation, realizes fluid delivery.Piezoelectric pump has the characteristics of extremely small volume, high integration, low power consumption, no magnetic interference, has unique advantage in microfluidic, high-end medical treatment, semiconductor thermal management and other fields, is especially suitable for microsystem integrated application.For example medical breathing machine.

[0003] The piezoelectric pump structure commonly used at present, one side of pump body is provided with air inlet, the other side is provided with air outlet, piezoelectric element is installed in pump body, and the volume of control cavity is changed by piezoelectric element deformation, so that gas enters exhaust cavity along the periphery flow channel from air inlet chamber, and then is discharged through air outlet.

[0004] Piezoelectric ceramic control valve is another kind of micro fluid control device, and piezoelectric pump is similar, also is the inverse piezoelectric effect of piezoelectric ceramic, makes piezoelectric vibrator produce deformation, only piezoelectric ceramic control valve forms fluid passage when piezoelectric ceramic deforms, forms closed structure when recovering, to control the on-off of fluid passage, and is used as fluid passage switch.

[0005] Since the existing piezoelectric ceramic fluid control device is mostly used in biochemical detection, blood pressure detection and other micro-analysis system feeding or jet control, micro-dosage control microfluid control field, its size and power supply voltage are not considered.But if it is used to cool power devices in small devices, especially in ultra-thin devices such as mobile phones, the problem of driving voltage and volume needs to be considered, and the working voltage needs to be reduced.The voltage of the current vibrator is high, and the requirement of the driving circuit is very high, the area occupied by the circuit board and the efficiency are contradictory to the light and thin demand of the product. UTILITY MODEL CONTENTS

[0006] The utility model aims at providing a kind of micro piezoelectric ceramic gas / liquid control device to solve the problem of high equipment driving voltage in the above background technology.

[0007] To achieve the above object, the utility model provides the following technical scheme:

[0008] A kind of micro piezoelectric ceramic gas / liquid control device, including control cavity, control cavity one side is equipped with piezoelectric ceramic, the piezoelectric ceramic is multilayer piezoelectric ceramic, each layer of the multilayer piezoelectric ceramic is equipped with first electrode and second electrode, the first electrode and the second electrode of the same layer are equipped with insulating band, and the first electrode and the second electrode of adjacent layer are electrically connected.

[0009] Specifically, the structure of the multilayer piezoelectric ceramic is a stack of a first multilayer piezoelectric ceramic, a base, and a second multilayer piezoelectric ceramic, and the first multilayer piezoelectric ceramic, the base, and the second multilayer piezoelectric ceramic are bonded by a glue layer.

[0010] Specifically, the bottom of the control cavity is provided with an inlet one-way valve and an outlet one-way valve.

[0011] Specifically, the piezoelectric ceramic is circular or square.

[0012] Specifically, the electrical connection between the first electrode and the second electrode of the adjacent layer relies on an electrode hole or a side wall electrode.

[0013] Specifically, the piezoelectric ceramic is fixed on the control cavity through a first fixed end and a second fixed end.

[0014] Specifically, the first fixed end and the second fixed end are respectively connected with the first electrode and the second electrode of the piezoelectric ceramic.

[0015] Specifically, the control cavity is provided with a stabilizing cavity below, the stabilizing cavity is provided with a pump inlet and a pump outlet, the pump outlet and the outlet one-way valve are located on the same side of the control cavity, and the pump inlet and the inlet one-way valve are located on the same side.

[0016] Specifically, the stabilizing cavity is provided with a support block below.

[0017] Further, the first fixed end and the second fixed end are respectively connected with the positive and negative poles of an external driving power supply.

[0018] Specifically, the inlet one-way valve and the outlet one-way valve are reed pieces fixed on one side of the cavity bottom and movably attached to the other side of the cavity bottom.

[0019] Compared with the prior art, the utility model has the advantages that:

[0020] The utility model discloses a multilayer piezoelectric ceramic structure, which effectively reduces the driving voltage of the piezoelectric ceramic, so that the miniature piezoelectric ceramic gas / liquid control device no longer needs a working voltage of about 180V and can be powered and driven by a control module of a common power supply safety voltage in a mobile phone or other electronic equipment.

[0021] The utility model discloses a multilayer piezoelectric ceramic structure, which has a large deformation and can produce a large flow.

[0022] The utility model discloses a P5 drive type piezoelectric ceramic material, which increases the Curie temperature and makes the product working temperature reach above 120 DEG C, so that the piezoelectric effect of the piezoelectric ceramic does not disappear when close to a heat source. The stability and adaptability of the product are improved.

[0023] The utility model discloses a low-temperature piezoelectric ceramic material, so that the electrode material can adopt silver electrode or the electrode material of low palladium content, reduce the material cost, the piezoelectric ceramic of the utility model discloses the multilayer piezoelectric ceramic process of casting, printing, can quick batch production, and the process is stable.

[0024] The utility model discloses piezoelectric ceramic fluid control device that single crystal piezoelectric ceramic is made, improved piezoelectric ceramic yield, reduced piezoelectric ceramic production cost, more favor product marketization popularization. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 For the utility model discloses a micro piezoelectric ceramic gas / liquid control device structure schematic view;

[0026] Figure 2 For the utility model discloses piezoelectric ceramic explosion Figure One ;

[0027] Figure 3 For the utility model discloses piezoelectric ceramic explosion Figure Two ;

[0028] Figure 4 For the utility model discloses piezoelectric ceramic explosion Figure Three .

[0029] In the drawing: 1, piezoelectric ceramic;2, import check valve;3, export check valve;4, cavity wall;5, first fixed end;6, second fixed end;7, cavity bottom;8, stable cavity;9, support block;10, pump import;11, pump export;12, first electrode;13, second electrode;14, electrode hole;15, side wall electrode. DETAILED DESCRIPTION

[0030] The technical scheme in the embodiments of the utility model will be described clearly and completely below in conjunction with the drawings in the embodiments of the utility model, and obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the utility model.

[0031] Embodiment 1:

[0032] Please refer to Figures 1-4The embodiment provides a micro piezoelectric ceramic gas / liquid control device, which comprises a control cavity, one side of the control cavity is provided with a piezoelectric ceramic 1, the bottom 7 of the control cavity is provided with an inlet one-way valve 2 and an outlet one-way valve 3, the inlet one-way valve 2 and the outlet one-way valve 3 are spring sheets fixed on one side of the bottom 7 and movably attached to the other side of the bottom 7. The piezoelectric ceramic is a multilayer piezoelectric ceramic 1, each layer of the multilayer piezoelectric ceramic 1 is provided with a first electrode 12 and a second electrode 13, the first electrode 12 and the second electrode 13 in the same layer are provided with an insulating strip, and the first electrode 12 and the second electrode 13 in adjacent layers are electrically connected through an electrode hole 14. The piezoelectric ceramic 1 is fixed on the control cavity through a first fixed end 5 and a second fixed end 6. The piezoelectric ceramic adopts a P5 driving type low-temperature piezoelectric ceramic material, and the first electrode 12 and the second electrode 13 adopt silver electrodes or silver-palladium electrodes. Each layer of the multilayer piezoelectric ceramic is 30-50 microns, and the driving voltage is 5V or 12V.

[0033] Specifically, the piezoelectric ceramic 1 is circular, the required installation space is small, and the power of the pump is large.

[0034] Embodiment 2

[0035] Different from embodiment 1, the piezoelectric ceramic 1 in the embodiment is square, the square shape is similar to the chip shape, the installation is convenient, the production is easy, the piezoelectric ceramic is cut, and the material utilization rate is high.

[0036] Different from embodiment 1, the first electrode 12 and the second electrode 13 in adjacent layers are connected through a side wall electrode 15, the investment of a punching machine is reduced, and the performance requirement of filling the electrode hole electrode is reduced.

[0037] The first fixed end 5 and the second fixed end 6 are respectively connected with the first electrode 12 and the second electrode 13 of the piezoelectric ceramic 1. The first fixed end 5 and the second fixed end 6 are respectively connected with the positive and negative poles of an external driving power supply.

[0038] A stabilizing cavity 8 is arranged below the control cavity, the stabilizing cavity 8 is provided with a pump inlet 10 and a pump outlet 11, the pump outlet 11 is located on the same side of the control cavity as the outlet one-way valve 3, and the pump inlet 10 is located on the same side as the inlet one-way valve 2. The stabilizing cavity can stabilize the gas flow or liquid flow, and ensure the stable work of the piezoelectric ceramic fluid control device.

[0039] A support block 9 is arranged below the stabilizing cavity 8, which provides a fixing point for the installation of the piezoelectric ceramic fluid control device. The support block 9 can also be connected with the first fixed end 5 and the second fixed end 6 through two stabilizing cavities 8 and a single cavity wall 4 respectively, so that the piezoelectric ceramic fluid control device becomes a patch device.

[0040] Embodiment 3

[0041] Different from example 1, the structure of the multilayer piezoelectric ceramic 1 is a word stack of first multilayer piezoelectric ceramic, substrate, second multilayer piezoelectric ceramic, which are bonded by adhesive layer. The first multilayer piezoelectric ceramic and the second multilayer piezoelectric ceramic are respectively composed of PZT-based piezoelectric material, and the first multilayer piezoelectric ceramic and the second multilayer piezoelectric ceramic can be the same component or different components. The substrate is made of supporting materials such as fiber sheet or metal sheet. In this embodiment, stainless steel sheet is used. When there are two multilayer piezoelectric ceramic layers, each multilayer piezoelectric ceramic can be driven by only a single-pole electric field, avoiding depolarization caused by electric field, and both large deformation and low driving voltage can be considered.

[0042] Example 4:

[0043] This embodiment provides a micro piezoelectric ceramic gas / liquid control device, which comprises a control cavity, and a piezoelectric ceramic 1 is arranged on one side of the control cavity. The piezoelectric ceramic is a multilayer piezoelectric ceramic 1, each layer of the multilayer piezoelectric ceramic 1 is provided with a first electrode 12 and a second electrode 13, an insulating belt is arranged between the first electrode 12 and the second electrode 13 of the same layer, and the first electrode 12 and the second electrode 13 of the adjacent layer are electrically connected through an electrode hole 14. The piezoelectric ceramic 1 is fixed on the control cavity through a first fixed end 5 and a second fixed end 6. The piezoelectric ceramic adopts P5 driving type low-temperature piezoelectric ceramic material, and the first electrode 12 and the second electrode 13 adopt silver electrode or silver-palladium electrode. Each layer of the multilayer piezoelectric ceramic is 30-50 microns, and the driving voltage is 5V or 12V.

[0044] In this way, a micro piezoelectric ceramic control valve is formed, which can control the flow of fluid through the control cavity at a lower driving voltage, and plays the role of flow switch.

[0045] Example 5: Preparation of multilayer piezoelectric ceramic

[0046] S1, purchase or self-preparation of low-temperature P5 driving type piezoelectric ceramic powder with sintering temperature of 950-1005℃;

[0047] S2, mix the piezoelectric ceramic powder with adhesive PVB, dispersing agent castor oil, solvent toluene, ethanol, etc., ball mill to obtain a liquid mixture with uniform dispersion and certain viscosity, use a casting machine to spread the liquid and dry to obtain a film of several tens of microns; if electrode hole 14 process is used, a punching machine is needed for backup;

[0048] S3, print silver-palladium paste on the surface of the ceramic film through screen printing, and dry;

[0049] S4, put the raw materials into the static pressure for pressure forming by using the tooling;

[0050] S5, cutting the ceramic diaphragm according to product specifications using a cutting machine;

[0051] S6, placing the ceramic blank into a high-temperature tunnel furnace, slowly increasing the temperature to 650 DEG C, and keeping the temperature for 1.5 hours to pre-eliminate organic binders and dispersants, thereby preventing the deformation and cracking of the blank;

[0052] S7, continuing to increase the temperature of the ceramic blank after the glue is removed in the high-temperature tunnel furnace to sinter the ceramic, and naturally cooling according to the sintering curve provided by the ceramic powder supplier;

[0053] S8, if side wall electrodes are used, then the side wall electrodes are brushed with a brush after sintering or before the glue is removed in S6, and if the electrodes are brushed after sintering, the electrodes need to be dried again at 400 DEG C;

[0054] S9, placing the sintered and layer-by-layer connected piezoelectric ceramic into an electrode rectifier unit electric field, with air as the insulating medium, the polarization temperature gradually decreasing from above the Curie temperature (10-20 DEG C higher than the Curie temperature, the Curie temperature of each material is different, and needs to be obtained from the ceramic powder provider) to below 100 DEG C, and the corresponding polarization electric field gradually increasing from weak (about 30 V / mm) to strong (about 300 V / mm), to complete the polarization of the ceramic blank.

[0055] Preparation of a micro piezoelectric ceramic gas / liquid control device:

[0056] Two groups of cavity walls 4 are fixed on the cavity bottom 7 by non-conductive glue such as epoxy, an insulating layer is brushed on the bottom of the piezoelectric ceramic 1, the prepared piezoelectric ceramic 1 is fixed on the cavity wall 4 by electrode glue, and the two groups of fixed electrode glue form a first fixed end 5 and a second fixed end 6.

[0057] The reed of the inlet one-way valve 2 is fixed on the top of the bottom of the cavity bottom 7, the reed of the outlet one-way valve 3 is fixed on the bottom of the cavity bottom 7, the stable cavity 8 is fixed and stabilized by sealing glue on the lower part of the cavity bottom 7, and the support block 9 is fixed by electrode glue below the stable cavity 8.

[0058] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, the scope of the present application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application, and any reference signs in the claims should not be regarded as limiting the claims involved.

[0059] The above merely describes a preferred embodiment of the present application, and the protection scope of the present application is not limited thereto, and any skilled person in the art, according to the technical scheme and the inventive concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A micro piezoelectric ceramic gas / liquid control device comprising a control cavity, one side of which is provided with a piezoelectric ceramic, characterized in that, The piezoelectric ceramic is a multilayer piezoelectric ceramic, each layer of the multilayer piezoelectric ceramic is provided with a first electrode and a second electrode, an insulating strip is arranged between the first electrode and the second electrode of the same layer, and the first electrode is in electrical communication with the second electrode of an adjacent layer; The electrical communication of the first electrode with the second electrode of the adjacent layer relies on electrode holes or side wall electrode communication; The piezoelectric ceramic is fixed on the control cavity through a first fixed end and a second fixed end; The first fixed end and the second fixed end are respectively in communication with the first electrode and the second electrode of the piezoelectric ceramic; The cavity bottom of the control cavity is provided with an inlet one-way valve and an outlet one-way valve; The multilayer piezoelectric ceramic comprises a first multilayer piezoelectric ceramic, a base, and a second multilayer piezoelectric ceramic, which are sequentially bonded together through adhesive layers; A stabilizing cavity is arranged below the control cavity, a pump inlet and a pump outlet are arranged on the stabilizing cavity, the pump outlet and the outlet one-way valve are located on the same side of the control cavity, the pump inlet and the inlet one-way valve are located on the same side, and a support block is arranged below the stabilizing cavity; The piezoelectric ceramic adopts a P5 driving type piezoelectric ceramic material, the first electrode and the second electrode adopt silver electrodes or silver-palladium electrodes, each layer of the multilayer piezoelectric ceramic is 30-50 microns, and the driving voltage is 5V or 12V; The base is made of a fiber sheet or a metal sheet.

2. The micro piezoelectric ceramic gas / liquid control device according to claim 1, wherein The first fixed end and the second fixed end are respectively in communication with the positive and negative poles of an external driving power supply.

3. The micro piezoelectric ceramic gas / liquid control device according to claim 1, wherein The inlet one-way valve and the outlet one-way valve are spring sheets fixed on one side of the cavity bottom and movably attached to the other side of the cavity bottom.

4. The micro piezoelectric ceramic gas / liquid control device according to claim 1, wherein The piezoelectric ceramic is circular or square.

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