阅读说明：本技术 一种低漏导高耐压固态电介质薄膜电容器及其制备方法 (Low-leakage-conductivity high-voltage-resistance solid dielectric film capacitor and preparation method thereof ) 是由 苏振 李在房 宋嘉兴 胡林 尹新星 金英芝 于 2021-05-21 设计创作，主要内容包括：本发明涉及电容器制备方法技术领域,涉及一种低漏导高耐压固态电介质薄膜电容器,包括壳体及封装在壳体内的电容器单元,所述电容器单元包括自上而下一次设置的上部电极、氧化物电介质薄膜、基底,所述氧化物电介质薄膜表面为一层结晶化的氧化物。还公开了一种低漏导高耐压固态电介质薄膜电容器的制备方法。本发明在选用的铝氧化合物表面经过结晶化处理,经过简单处理,实现了同一薄膜具有两种不同的结构,使该类铝氧化合物电介质薄膜的漏电流和击穿场强得到有效提升。(The invention relates to the technical field of capacitor preparation methods, in particular to a low-leakage-conductance high-voltage-resistance solid dielectric film capacitor which comprises a shell and a capacitor unit encapsulated in the shell, wherein the capacitor unit comprises an upper electrode, an oxide dielectric film and a substrate which are arranged from top to bottom at one time, and the surface of the oxide dielectric film is a layer of crystallized oxide. Also discloses a preparation method of the low-leakage-conductivity high-voltage-resistance solid dielectric film capacitor. According to the invention, the surface of the selected aluminum oxide compound is subjected to crystallization treatment and simple treatment, so that the same film has two different structures, and the leakage current and the breakdown field strength of the aluminum oxide compound dielectric film are effectively improved.)

1. A low leakage and high voltage resistance solid dielectric film capacitor is characterized in that: the capacitor unit comprises an upper electrode, an oxide dielectric film and a substrate which are arranged from top to bottom at one time, wherein the surface of the oxide dielectric film is a layer of crystallized oxide.

2. A low leakage, high withstand voltage solid dielectric film capacitor as claimed in claim 1, wherein: the oxide dielectric film is an aluminum oxide compound and has a thickness of 200-300 nm.

3. A low leakage, high withstand voltage solid dielectric film capacitor as claimed in claim 1 or 2, wherein: the thickness of the oxide crystallized on the surface of the oxide dielectric film is 5-10 nm.

4. A low leakage, high withstand voltage solid dielectric film capacitor as claimed in claim 3, wherein: the upper electrode is a metal electrode with a thickness of 150-250 nm.

5. The low leakage conductance high withstand voltage solid dielectric thin film capacitor as claimed in claim 4, wherein: the upper electrode is deposited on the oxide dielectric film.

6. A method for manufacturing a low leakage conduction high withstand voltage solid dielectric film capacitor as claimed in claim 5, characterized in that: the method specifically comprises the following steps:

(1) preparing an aluminum oxide sol precursor:

(1-1) grinding 0.01-0.02mol of aluminum isopropoxide, then adding into 50-60mL of ethylene glycol ethyl ether for ultrasonic dispersion for 10-30min, and stirring at the constant temperature of 60-80 ℃ for 0.5-1 h;

(1-2) adding 0.02-0.03mol of acetylacetone into the solution obtained in the step (1-1), and stirring at a constant temperature of 60-80 ℃ for 0.5-1h to obtain a solution;

(1-3) adding 10mL of glacial acetic acid into the solution obtained in the step (1-2), and stirring at the constant temperature of 60-80 ℃ for 0.5-1h to obtain a clear sol precursor;

(2) coating the sol precursor prepared in the step (1-3) on a substrate, and performing heat treatment to prepare 1 layer of the oxide film; repeating the step for 5-9 times, and annealing at 450 deg.C for 3-5h to obtain aluminum oxide film;

(3) subjecting the surface of the alundum film obtained in the step (2) to Plasma to obtain an alundum film with crystallized surface;

(4) preparing a layer of metal film on the aluminum oxide film by adopting an evaporation coating method or a magnetron sputtering method to be used as an upper electrode to obtain a capacitor unit;

(5) and packaging and curing the prepared capacitor units or the capacitor units by using an insulating medium, and then leading wires at two ends to obtain the low-leakage-conductance high-voltage-resistance solid dielectric film capacitor.

7. The method for manufacturing a low leakage conduction high withstand voltage solid dielectric film capacitor as claimed in claim 6, wherein: the thickness of the aluminum oxide thin film prepared in the step (2) is 200-300 nm.

8. The method for manufacturing a low leakage conduction high withstand voltage solid dielectric film capacitor as claimed in claim 6, wherein: the substrate adopted in the step (2) is a hard or flexible substrate, and the substrate is an organic or inorganic material.

9. The method for manufacturing a low leakage conduction high withstand voltage solid dielectric film capacitor as claimed in claim 6, wherein: the Plasma treatment time of the surface of the aluminum oxide film in the step (3) is 0.5-5 min.

10. The method for manufacturing a low leakage conduction high withstand voltage solid dielectric film capacitor as claimed in claim 6, wherein: the thickness of the aluminum oxygen compound crystallized on the surface of the aluminum oxygen compound film in the step (3) is 5-10 nm.

Technical Field

The invention relates to the technical field of capacitor preparation methods, in particular to a low-leakage-conductivity high-voltage-resistance solid dielectric film capacitor and a preparation method thereof.

Background

At present, a dielectric energy storage device with high energy storage density and high efficiency is one of the most basic and critical elements in devices such as integrated circuits and high-energy pulse power, and the dielectric energy storage device is widely applied to important civil and national defense devices such as medical defibrillators, hybrid electric vehicles, transducers, electromagnetic rail guns, laser weapons and the like. In addition, high stability and high energy storage are important as a key index for measuring the working stability and performance of the electronic device. Leakage current is a key parameter of a dielectric capacitor, and large leakage current causes large loss of an energy storage device and brings a heating problem, so that the long-term use stability of the device is influenced. The high energy storage is closely related to the withstand voltage field strength of the dielectric material, and the high breakdown field strength can greatly improve the energy storage density of the dielectric capacitor.

The oxide dielectric material is used as an inorganic substance, and has high stability and great development potential. Particularly, the aluminum oxide compound is a common oxide, has rich reserves, low price and excellent superiority in the aspect of application and popularization. At present, dielectric capacitors taking aluminum oxide as a medium have a large number of applications, but the compressive strength is still low, and the leakage conductance is too high. In order to solve the above problems, a great number of researchers optimize the withstand voltage and the drain conductance by doping the aluminum oxide compound or by stacking other oxide layers, such as boron element, silicon element, barium titanate, and the like. Whether doping or stacking, the process is complicated, and the process has certain difficulty due to the agglomeration effect of the nanoparticles or the compatibility between different oxides.

Disclosure of Invention

The invention provides a low-leakage-conductivity high-voltage-resistance solid dielectric film capacitor and a preparation method thereof to solve the technical defects, and the energy storage density and the stability of the capacitor can be improved.

The invention discloses a low-leakage-conductance high-voltage-resistance solid dielectric film capacitor, which comprises a shell and a capacitor unit encapsulated in the shell, wherein the capacitor unit comprises an upper electrode, an oxide dielectric film and a substrate which are arranged from top to bottom at one time, and the surface of the oxide dielectric film is a layer of crystallized oxide.

Preferably, the oxide dielectric film is an aluminum oxide compound with the thickness of 200-300 nm; the texture is uniform, and the breakdown field strength can reach 750 MV/m.

Preferably, the thickness of the oxide crystallized on the surface of the oxide dielectric film is 5-10 nm.

Preferably, the upper electrode is a metal electrode with a thickness of 150-250 nm.

Preferably, the upper electrode is deposited on the oxide dielectric film.

A preparation method of a low-leakage-conductivity high-voltage-resistance solid dielectric film capacitor specifically comprises the following steps:

(1) preparing an aluminum oxide sol precursor:

(1-1) grinding 0.01-0.02mol of aluminum isopropoxide, then adding into 50-60mL of ethylene glycol ethyl ether for ultrasonic dispersion for 10-30min, and stirring at the constant temperature of 60-80 ℃ for 0.5-1 h;

(1-2) adding 0.02-0.03mol of acetylacetone into the solution obtained in the step (1-1), and stirring at a constant temperature of 60-80 ℃ for 0.5-1h to obtain a solution;

(1-3) adding 10mL of glacial acetic acid into the solution obtained in the step (1-2), and stirring at the constant temperature of 60-80 ℃ for 0.5-1h to obtain a clear sol precursor;

(2) coating the sol precursor prepared in the step (1-3) on a substrate, and performing heat treatment to prepare 1 layer of the oxide film; repeating the step for 5-9 times, and annealing at 450 deg.C for 3-5h to obtain aluminum oxide film;

(3) subjecting the surface of the alundum thin film obtained in the step (2) to Plasma treatment (Plasma excimer treatment) to obtain an alundum thin film with crystallized surface;

(4) preparing a layer of metal film on the aluminum oxide film by adopting an evaporation coating method or a magnetron sputtering method to be used as an upper electrode to obtain a capacitor unit;

(5) and packaging and curing the prepared capacitor units or the capacitor units by using an insulating medium, and then leading wires at two ends to obtain the low-leakage-conductance high-voltage-resistance solid dielectric film capacitor.

The thickness of the aluminum oxide thin film prepared in the step (2) is 200-300 nm.

The substrate adopted in the step (2) is a hard or flexible substrate, and the substrate is an organic or inorganic material.

The Plasma treatment time of the surface of the aluminum oxide film in the step (3) is 0.5-5 min.

The thickness of the aluminum oxygen compound crystallized on the surface of the aluminum oxygen compound film in the step (3) is 5-10 nm.

According to the low-leakage-conductivity high-voltage-resistance solid dielectric film capacitor and the preparation method thereof, the low-cost aluminum oxide is selected as a main substrate, and a layer of crystallized aluminum oxide is obtained on the surface of the film through Plasma treatment. Because the surface of the aluminum oxide compound is crystallized, the surface leakage conductance is effectively guided and reduced. And because the leakage conductance is reduced, the thermal breakdown is effectively restrained, and the breakdown field intensity of the film is further improved. Different from other solid-state capacitors which are researched in a large amount at present, the invention realizes that the same film has two different structures by performing crystallization treatment and simple treatment on the surface of the selected aluminum oxide compound, so that the leakage current and the breakdown field strength of the aluminum oxide compound dielectric film are effectively improved.

Compared with the prior art, the invention has the advantages that:

the selected aluminum oxide compound has low cost, simple preparation process, short time period and easy mass production.

The solid capacitor prepared by the invention has high energy storage density, high voltage resistance, low leakage conductance and very high use limit.

Drawings

FIG. 1 is a flow chart illustrating the fabrication of a capacitor according to the present invention;

FIG. 2 is a schematic structural diagram of a capacitor unit according to the present invention;

FIG. 3 is a J-E characteristic of the capacitor of the present invention.

Detailed Description

To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, the following detailed description of the embodiments, structures, features and effects according to the present invention will be made with reference to the accompanying drawings and preferred embodiments.

Example 1:

as shown in fig. 2, the present invention discloses a low leakage conductance high withstand voltage solid dielectric film capacitor, which comprises a housing and a capacitor unit encapsulated in the housing, wherein the capacitor unit comprises an upper electrode, an oxide dielectric film and a substrate which are arranged from top to bottom at one time, and the surface of the oxide dielectric film is a layer of crystallized oxide. The oxide dielectric film is an aluminum oxide compound and has the thickness of 210 nm; the texture is uniform. The thickness of the oxide crystallized on the surface of the oxide dielectric film is 5 nm.

The upper electrode is a metal electrode with a thickness of 150 nm.

The upper electrode is deposited on the oxide dielectric film.

As shown in fig. 1, a method for manufacturing a low leakage conductance high withstand voltage solid dielectric film capacitor specifically includes the following steps:

(1) preparing an aluminum oxide sol precursor:

(1-1) grinding 0.01mol of aluminum isopropoxide, then adding the ground aluminum isopropoxide into 50mL of ethylene glycol ethyl ether for ultrasonic dispersion for 30min, and stirring the mixture at a constant temperature of 60 ℃ for 1 h;

(1-2) adding 0.02mol of acetylacetone into the solution obtained in the step (1-1), and stirring at a constant temperature of 60 ℃ for 0.5h to obtain a solution;

(1-3) adding 10mL of glacial acetic acid into the solution obtained in the step (1-2), and stirring at a constant temperature of 60 ℃ for 0.5-1h to obtain a clear sol precursor;

(2) coating the sol precursor prepared in the step (1-3) on a substrate, and performing heat treatment to prepare 1 layer of the oxide film; repeating the step for 5-9 times, and annealing at 450 deg.C for 3h to obtain aluminum oxide film;

(3) performing Plasma treatment on the surface of the aluminoxy compound film obtained in the step (2) to obtain a surface crystallized aluminoxy compound film;

(4) preparing a layer of metal film on the aluminum oxide film by adopting an evaporation coating method or a magnetron sputtering method to be used as an upper electrode to obtain a capacitor unit;

(5) and packaging and curing the prepared capacitor units or the capacitor units by using an insulating medium, and then leading wires at two ends to obtain the low-leakage-conductance high-voltage-resistance solid dielectric film capacitor.

The Plasma treatment time of the surface of the aluminum oxide film in the step (3) is 0.5 min.

The J-E characteristics of the resulting capacitor are shown in FIG. 3.

Example 2:

in this example, the dielectric oxide was changed to a 300nm aluminum oxy compound dielectric film and the upper electrode was an aluminum electrode.

Grinding 0.02mol of aluminum isopropoxide, adding the ground aluminum isopropoxide into 50mL of ethylene glycol ethyl ether, performing ultrasonic treatment for 10min, and stirring the mixture for 30min at 70 ℃; adding 0.03mol of acetylacetone, and stirring for 30 minutes at 60 ℃; 10mL of acetic acid was added and stirred at 60 ℃ for 30 minutes. After the reaction was completed, the mixture was gradually cooled to room temperature, and finally filtered to obtain 60mL of a clear aluminum oxy compound precursor. The method comprises the steps of flatly placing Pt with a clean and dry surface on a silicon wafer, placing the Pt on a spin coater, dripping a sol precursor on the surface of the substrate, uniformly coating the sol on the surface of the substrate at the rotating speed of 3000 r/min, placing a sample in a tubular furnace for drying heat treatment, wherein the process conditions of pre-drying treatment are that the Pt is treated at 150 ℃ for 2 minutes under the air condition, treated at 350 ℃ for 2 minutes and treated at 450 ℃ for 2 minutes, and after 10 layers of the Pt are thrown, placing the prepared amorphous oxide film with the required thickness in a furnace, and keeping the temperature at 450 ℃ for 3 hours. Finally, the obtained film is pretreated for 1min by Plasma.

An aluminum film with the diameter of 1 millimeter and the thickness of 120nm is prepared on the surface of an oxide film sample by adopting vacuum evaporation equipment and is used as an electrode, and the breakdown field strength and the leakage conductance of the capacitor are researched.

Example 3:

in this example, the rigid capacitor was changed to a flexible capacitor, and the upper electrode was prepared as a gold electrode and the substrate was a flexible aluminum foil.

Grinding 0.02mol of aluminum isopropoxide, adding the ground aluminum isopropoxide into 60mL of ethylene glycol ethyl ether, performing ultrasonic treatment for 10min, and stirring the mixture for 30min at 70 ℃; adding 0.03mol of acetylacetone, and stirring for 30 minutes at 60 ℃; 10mL of acetic acid was added and stirred at 60 ℃ for 30 minutes. After the reaction was completed, the mixture was gradually cooled to room temperature, and finally filtered to obtain 60mL of a clear aluminum oxy compound precursor. The preparation method comprises the steps of flatly placing an aluminum foil with a clean and dry surface on a silicon wafer, placing the aluminum foil on a spin coater, dripping a sol precursor on the surface of the substrate, uniformly coating the sol on the surface of the substrate at a rotating speed of 3000 r/min, placing a sample in a tubular furnace for drying heat treatment, pre-drying at 150 ℃ for 2 min under the air condition, treating at 350 ℃ for 2 min, treating at 450 ℃ for 2 min, throwing to 7 layers, and placing an amorphous oxide film with the required thickness in the furnace for heat preservation at 450 ℃ for 3 h. Finally, the obtained film is pretreated for 1min by Plasma.

A gold film with the diameter of 1 mm and the thickness of 120nm is prepared on the surface of an oxide film sample by adopting vacuum evaporation equipment and is used as an electrode, and the breakdown field strength and the leakage conductance of the capacitor are researched.

Example 4:

the thickness of the surface crystalline alumina film is increased, and the surface pretreatment time of the aluminum oxide compound is prolonged to 5 min.

Grinding 0.02mol of aluminum isopropoxide, adding the ground aluminum isopropoxide into 50mL of ethylene glycol ethyl ether, performing ultrasonic treatment for 10min, and stirring the mixture for 30min at 70 ℃; adding 0.03mol of acetylacetone, and stirring for 30 minutes at 60 ℃; 10mL of acetic acid was added and stirred at 80 ℃ for 30 minutes. After the reaction was completed, the mixture was gradually cooled to room temperature, and finally filtered to obtain 60mL of a clear aluminum oxy compound precursor. The method comprises the steps of flatly placing Pt with a clean and dry surface on a silicon wafer, placing the Pt on a spin coater, dripping a sol precursor on the surface of a substrate, uniformly coating the sol on the surface of the substrate at the rotating speed of 3000 r/min, placing a sample in a tubular furnace for drying heat treatment, pre-drying treatment under the process condition of heating at 450 ℃ for 5min under the air condition, throwing to 7 layers, and placing the prepared amorphous oxide film with the required thickness in the furnace for heat preservation at 450 ℃ for 3 h. Finally, the obtained film is pretreated for 5min by Plasma.

A gold film with the diameter of 1 mm and the thickness of 120nm is prepared on the surface of an oxide film sample by adopting vacuum evaporation equipment and is used as an electrode, and the breakdown field strength and the leakage conductance of the capacitor are researched.

Example 5:

a PET flexible solid dielectric capacitor with Au as the upper electrode was prepared.

Grinding 0.02mol of aluminum isopropoxide, adding the ground aluminum isopropoxide into 50mL of ethylene glycol ethyl ether, performing ultrasonic treatment for 10min, and stirring the mixture for 30min at 70 ℃; adding 0.03mol of acetylacetone, and stirring for 30 minutes at 60 ℃; 10mL of acetic acid was added and stirred at 60 ℃ for 30 minutes. After the reaction was completed, the mixture was gradually cooled to room temperature, and finally filtered to obtain 60mL of a clear aluminum oxy compound precursor. Placing PET with a clean and dry surface on a silicon wafer flatly, placing the PET on a spin coater, dripping a sol precursor on the surface of the substrate, uniformly coating the sol on the surface of the substrate at the rotating speed of 3000 r/min, then placing a sample in a tubular furnace for drying heat treatment, wherein the process conditions of pre-drying treatment are 150 ℃ for 2 minutes under an air condition, 350 ℃ for 2 minutes, 450 ℃ for 2 minutes, throwing to 7 layers, and placing the prepared amorphous oxide film with the required thickness in the furnace for heat preservation at 450 ℃ for 3 hours. Finally, the obtained film is pretreated for 1min by Plasma.

A gold film with the diameter of 1 mm and the thickness of 120nm is prepared on the surface of an oxide film sample by adopting vacuum evaporation equipment and is used as an electrode, and the breakdown field strength and the leakage conductance of the capacitor are researched.

Although the present invention has been described with reference to the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but may be embodied or carried out in various forms without departing from the spirit and scope of the invention.