Preparation method of ZnO array film type piezoresistor

Abstract

The invention discloses a preparation method of a ZnO array film type piezoresistor, which is used in the field of piezoresistor preparation and specifically comprises the following steps: growing a ZnO nano array on a high-temperature-resistant conductive substrate by adopting an electrodeposition method, preparing additive slurry which comprises the following components in percentage by mass: 10-70 percent of Bi2O3, 0-50 percent of NiO, 0-20 percent of Cr2O3, 5-50 percent of Mn3O4, 5-50 percent of Co3O4 and 0-30 percent of SiO2, preparing the additive slurry of S2 for later use, and preparing the ZnO nano array on the high-temperature-resistant conductive substrate by adopting an electrodeposition method. S4, a composite additive is applied to the ZnO array film through a spin-coating method, the spin-coating speed is 300-600 r / min, the spin-coating time is 10-60 s, the array film in the step S4 is pre-calcined at 350-500 DEG C, and organic matter is discharged. The array film type varistor prepared by the invention is beneficial to the improvement of the electrical property of a low-voltage varistor, particularly has more obvious influence on an ultra-low-voltage varistor less than 5V, and is beneficial to meeting the protection requirements of modern electronic systems such as various integrated circuits, precise electronic circuits and chips.

Description

Technical Field

[0001] The present invention relates to the field of varistor preparation, and in particular to a method for preparing a ZnO array film varistor. Background Art

[0002] A varistor is a resistor device with nonlinear volt-ampere characteristics. Its resistance value changes sensitively with the increase of applied voltage, and it has the function of suppressing transient overvoltage. Varistors are usually connected in parallel with the circuits or electronic components to be protected. When the transient overvoltage in the circuit exceeds the threshold voltage of the varistor, its resistance will drop sharply, and the current through the varistor will increase by several orders of magnitude, while the voltage increase is very small, thereby achieving the function of protecting the parallel circuits or electronic components. In order to meet the protection needs of various integrated circuits, precision electronic circuits and chips, the demand for low-voltage ZnO varistors is increasing, and the requirements for their performance are also getting higher and higher.

[0003] Since the thickness of low-voltage varistors is very thin and the number of grains in the thickness direction is very small, the problem of uneven electrical properties caused by uneven grain size will be very prominent.

[0004] In order to solve the problems of the prior art, the purpose of the present invention is to overcome the shortcomings of the existing technology and provide a method for preparing an array-type thin-film varistor that can accurately control the varistor voltage and improve the consistency of electrical performance. This structure is conducive to improving the electrical performance of low-voltage varistors, especially for ultra-low-voltage varistors less than 5V, which is more obvious, and is conducive to achieving the protection needs of modern electronic systems such as various integrated circuits, precision electronic circuits and chips.

[0005] Currently, no effective solution has been proposed for the problems in the related technologies. Summary of the invention

[0006] In order to overcome the above problems, the present invention aims to propose a method for preparing a ZnO array film varistor, with the purpose of providing a method for preparing an array thin film varistor that can accurately control the varistor voltage and improve the consistency of electrical performance. This structure is conducive to improving the electrical performance of low-voltage varistors.

[0007] To this end, the specific technical solution adopted by the present invention is as follows:

[0008] According to one aspect of the present invention, a method for preparing a ZnO array film varistor is provided, and the preparation method specifically comprises the following steps:

[0009] S1, growing ZnO nanoarrays on a high temperature resistant conductive substrate using electrodeposition;

[0010] S2. Prepare an additive slurry, the components of which include by mass percentage: Bi2O3: 10-70wt.%, NiO: 0-50wt.%, Cr2O3: 0-20wt.%, Mn3O4: 5-50wt.%, Co3O4: 5-50wt.%, SiO2: 0-30wt.%;

[0011] S3, prepare the additive slurry of S2 for standby use;

[0012] S4, applying the composite additive on the ZnO array film by spin coating, the spin coating speed is 300-600 rpm, and the time is 10-60 s;

[0013] S5. Pre-calcining the array membrane in step S4 at 350-500° C. to discharge organic matter.

[0014] Optionally, the specific process of growing the ZnO nanoarray on the high temperature resistant conductive substrate by electrodeposition is as follows:

[0015] S11, vapor-depositing a layer of Pt on a high temperature resistant conductive ceramic substrate as a bottom electrode;

[0016] S12, prepare a mixed aqueous solution of zinc nitrate and hexamethylenetetramine, maintain the solution temperature at 70-95°C, use the Pt evaporated in step S11 as the negative electrode, apply a voltage of 2.1V, perform electrochemical deposition for 30-180 minutes, and rinse with deionized water to obtain a ZnO array film.

[0017] Optionally, the specific process of preparing the additive slurry S2 for use is as follows:

[0018] S31, mixing the raw materials prepared in step S2 with deionized water to form a mixed slurry, and making the mixed slurry reach a solid content of not less than 30% by mass, and then adding the solid suspension into a horizontal sand mill, and sand milling for 30-90 minutes, so that the particle size of the slurry reaches 0.3-0.6 μm;

[0019] S32, drying the slurry prepared in step S31 and then calcining it, the calcination temperature is 900-1200°C, and the calcination time is 1-4h.

[0020] Optionally, the array membrane in step S4 is pre-calcined at 350-500° C. to discharge organic matter. The specific process is as follows:

[0021] S51, calcining the pre-calcined green body at a high temperature of 800-1200° C. for 30-120 min;

[0022] S52 , depositing a Pt electrode on the array film calcined in step S51 to form a ZnO array film varistor.

[0023] Optionally, in step S12, the electrochemical deposition time is 60-120 minutes.

[0024] Optionally, in step S32, the calcination temperature is 950-1100° C., and the calcination time is 2-3 hours.

[0025] A varistor prepared by a method for preparing a ZnO array film varistor is characterized in that it includes a top metal electrode, a composite additive layer, a ZnO array film, a bottom conductive layer and a high-temperature resistant conductive substrate arranged in sequence from top to bottom.

[0026] Compared with the prior art, this application has the following beneficial effects:

[0027] 1. The array film varistor prepared by the present invention is beneficial to improving the electrical performance of low-voltage varistors, especially the ultra-low voltage varistors less than 5V, which is beneficial to realizing the protection requirements of modern electronic systems such as various integrated circuits, precision electronic circuits and chips.

[0028] 2. The process of the present invention is simple and does not require large-scale precision ceramic chip processing equipment. The prepared varistor has a small volume and a strong current-carrying capacity, and can achieve a lower varistor voltage than a multilayer varistor. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above characteristics, features and advantages of the present invention and their implementation methods and methods will become more clearly understood in conjunction with the following description of the embodiments, which are described in detail in conjunction with the accompanying drawings. Herein, a schematic diagram is shown:

[0030] Figure 1 The present invention is a flowchart of a method for preparing a ZnO array film varistor according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0032] According to an embodiment of the present invention, a method for preparing a ZnO array film varistor is provided.

[0033] The present invention will now be further described with reference to the accompanying drawings and specific implementation methods.

[0034] Embodiment 1

[0035] like Figure 1 As shown, according to one embodiment of the present invention, a method for preparing a ZnO array film varistor is provided, and the preparation method specifically comprises the following steps:

[0036] S1. Growing ZnO nanoarrays on a high temperature resistant conductive substrate by electrodeposition. The specific process is as follows;

[0037] S11, vapor-depositing a layer of Pt on a high temperature resistant conductive ceramic substrate as a bottom electrode;

[0038] S12, prepare a mixed aqueous solution of zinc nitrate and hexamethylenetetramine, maintain the solution temperature at 70-95°C, use the Pt evaporated in step S11 as the negative electrode, apply a voltage of 2.1V, perform electrochemical deposition for 30-180 minutes, and rinse with deionized water to obtain a ZnO array film.

[0039] S2. Prepare an additive slurry, the components of which include by mass percentage: Bi2O3: 10-70wt.%, NiO: 0-50wt.%, Cr2O3: 0-20wt.%, Mn3O4: 5-50wt.%, Co3O4: 5-50wt.%, SiO2: 0-30wt.%;

[0040] S3, prepare the additive slurry of S2 for standby use, the specific process is as follows:

[0041] S31, mixing the raw materials prepared in step S2 with deionized water to form a mixed slurry, and making the mixed slurry reach a solid content of not less than 30% by mass, and then adding the solid suspension into a horizontal sand mill, and sand milling for 30-90 minutes, so that the particle size of the slurry reaches 0.3-0.6 μm;

[0042] S32, drying the slurry prepared in step S31 and then calcining it, the calcination temperature is 900-1200° C., and the calcination time is 1-4 hours;

[0043] S4, applying the composite additive on the ZnO array film by spin coating, the spin coating speed is 300-600 rpm, and the time is 10-60 s;

[0044] S5, pre-calcining the array membrane in step S4 at 350-500°C to discharge organic matter. The specific process is as follows:

[0045] S51, calcining the pre-calcined green body at a high temperature of 800-1200° C. for 30-120 min;

[0046] S52 , depositing a Pt electrode on the array film calcined in step S51 to form a ZnO array film varistor.

[0047] Embodiment 2

[0048] In step S12, the electrochemical deposition time is 60-120 minutes.

[0049] In step S32, the calcination temperature is 950-1100° C., and the calcination time is 2-3 hours.

[0050] Embodiment 3

[0051] A varistor prepared by a method for preparing a ZnO array film varistor comprises a top metal electrode, a composite additive layer, a ZnO array film, a bottom conductive layer and a high temperature resistant conductive substrate which are arranged in sequence from top to bottom.

[0052] Although the present invention has been disclosed as above with preferred embodiments, the embodiments are merely examples for the convenience of description and are not intended to limit the present invention. Those skilled in the art may make several changes and modifications without departing from the spirit and scope of the present invention. The scope of protection claimed by the present invention shall be based on the claims.

Claims

1. A method for preparing a ZnO array film varistor, characterized in that: The preparation method specifically comprises the following steps: S1, growing ZnO nanoarrays on a high temperature resistant conductive substrate using electrodeposition; S2. Prepare an additive slurry, the components of which include by mass percentage: Bi2O3: 10-70wt.%, NiO: 0-50wt.%, Cr2O3: 0-20wt.%, Mn3O4: 5-50wt.%, Co3O4: 5-50wt.%, SiO2: 0-30wt.%; S3, prepare the additive slurry of S2 for standby use; S4, applying the composite additive on the ZnO array film by spin coating, the spin coating speed is 300-600 rpm, and the time is 10-60 s; S5. Pre-calcining the array membrane in step S4 at 350-500° C. to discharge organic matter.

2. The method for preparing a ZnO array film varistor according to claim 1, characterized in that: The specific process of growing ZnO nanoarray on a high temperature resistant conductive substrate by electrodeposition is as follows: S11, vapor-depositing a layer of Pt on a high temperature resistant conductive ceramic substrate as a bottom electrode; S12, prepare a mixed aqueous solution of zinc nitrate and hexamethylenetetramine, maintain the solution temperature at 70-95°C, use the Pt evaporated in step S11 as the negative electrode, apply a voltage of 2.1V, perform electrochemical deposition for 30-180 minutes, and rinse with deionized water to obtain a ZnO array film.

3. The method for preparing a ZnO array film varistor according to claim 1, characterized in that: The specific process of preparing the additive slurry S2 for use is as follows: S31, mixing the raw materials prepared in step S2 with deionized water to form a mixed slurry, and making the mixed slurry reach a solid content of not less than 30% by mass, and then adding the solid suspension into a horizontal sand mill, and sand milling for 30-90 minutes, so that the particle size of the slurry reaches 0.3-0.6 μm; S32, drying the slurry prepared in step S31 and then calcining it, the calcination temperature is 900-1200°C, and the calcination time is 1-4h.

4. The method for preparing a ZnO array film varistor according to claim 1, characterized in that: The specific process of pre-calcining the array membrane in step S4 at 350-500° C. to discharge organic matter is as follows: S51, calcining the pre-calcined green body at a high temperature of 800-1200° C. for 30-120 min; S52 , depositing a Pt electrode on the array film calcined in step S51 to form a ZnO array film varistor.

5. The method for preparing a ZnO array film varistor according to claim 2, characterized in that: In the step S12, the electrochemical deposition time is 60-120 minutes.

6. The method for preparing a ZnO array film varistor according to claim 3, characterized in that: In the step S32, the calcination temperature is 950-1100° C., and the calcination time is 2-3 hours.

7. The varistor prepared by the method for preparing a ZnO array film varistor according to any one of claims 1 to 6, characterized in that: The invention comprises a top metal electrode, a composite additive layer, a ZnO array film, a bottom conductive layer and a high temperature resistant conductive substrate which are arranged in sequence from top to bottom.

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