CN114836738A - Capacitor film grading treatment device and method - Google Patents

Abstract

The invention discloses a capacitor film grading treatment device and a capacitor film grading treatment method. The pretreatment unit regulates and controls the surface roughness of the film through surface treatment of discharge plasma, and improves the adhesive force of the film substrate. The functional layer deposition unit deposits a nanometer functional layer on the film substrate through an atomic layer deposition technology, so that the charge injection of the metal layer to the film material is inhibited, the breakdown field intensity threshold of the metalized film is improved, and the isolation self-healing performance of the metalized film is improved. The invention combines the plasma technology and the atomic layer deposition technology, quickly deposits the stable functional coating on the surface of the film and greatly improves the electrical performance of the capacitor film. Compared with the prior art, the grading continuous treatment method provided by the invention has the advantages of low cost, simple and convenient device, flexibility, high efficiency and the like, and is suitable for large-scale industrial production and application.

Description

A kind of capacitor film classification processing device and method

technical field

The invention belongs to the field of capacitors, and in particular relates to a capacitor film grading processing device and method.

Background technique

Metallized films are widely used in the manufacture of dry capacitors due to their excellent comprehensive properties such as working field strength, dielectric constant, and dielectric loss. Metallized film capacitors have self-healing properties, can work under critical breakdown field strength, and have high energy storage density. They are widely used in power systems, pulse power, aerospace and other fields. However, there are still some problems in the preparation process of metallized film capacitors. For example, after the metal electrode is evaporated, the breakdown field strength of the metallized film decreases significantly due to problems such as metallization damage, interface bonding defects or uneven evaporation, and it is difficult to meet the normal operation under high field strength conditions. Therefore, how to improve the interface problem and improve the breakdown strength of the metallized film during the manufacturing process of the metallized film is an urgent problem to be solved in the production of the film capacitor.

At present, the preparation process of film capacitors includes: white film, film metallization, component rolling, end gold spraying, component heat setting, energization, screening, core manufacturing, product potting, etc. In the manufacturing process of film capacitors, film metallization is an important part, and metallization technology has a direct impact on the electrical properties of capacitor films. In the prior art, the production process of film capacitors has the following defects: the process of film metallization will cause problems such as substrate damage, interface bonding defects or uneven evaporation, resulting in a significant drop in the breakdown field strength of the metallized film, affecting the film. The operating life of the capacitor. This problem has not been resolved for a long time.

The Chinese invention patent publication number CN 107705988A proposes a method for preparing a film capacitor. After stacking metallized polypropylene films and winding them to form a core, a pretreatment process is added: the cold-pressed core is placed in a sealed container. In the space, adjust the temperature to 40 ℃ ± 5 ℃, the humidity is below 35% RH, and the storage time is 2-10 hours. Although this method can effectively eliminate various stresses on the film, it is not easy to deform, and can ensure that the end face of the core is effectively drawn out, so that the gold spray layer is not easily deformed, but it cannot solve the problem of interface defects at the interface between the metal and the film. The Chinese invention patent with publication number CN108962597A proposes a continuous production device and method for high temperature and high performance capacitor films. The method mainly solves the performance of capacitors at high temperatures, and does not mention the problem of interface defects in metallized films.

Plasma surface treatment technology and atomic layer deposition (ALD) are emerging technologies developed in recent years. Plasma surface treatment technology has the advantages of fast, efficient, clean, and does not damage the performance of the substrate itself. Ionized gas is generated by high-voltage discharge, in which there are a large number of active particles, which cause the surface of the material to undergo reactions such as etching, activation, and cross-linking, thereby changing the surface properties of the material. Only the nanometer-scale thickness of the surface is involved in the action process, which improves the surface properties of the material without affecting the overall physical and chemical properties. Atomic layer deposition technology is based on the self-limiting growth characteristics of reactants, and a method of forming a deposited film by alternately passing gas-phase precursor pulses into the reactor and chemical adsorption reaction on the deposition substrate. The advantages of ALD include: the deposition process is a saturated chemical adsorption process, which can ensure the formation of large-area uniform films; control the reaction cycle to precisely control the film thickness and film growth; can be performed at low temperature; widely applicable to various shapes of substrates.

SUMMARY OF THE INVENTION

In view of the above technical problems, the present invention proposes a capacitor film grading treatment device and method for functionally modifying the interface and improving the breakdown strength of the metallized film by introducing a pretreatment unit and a functional deposition unit.

To achieve the above object, the technical scheme adopted in the present invention is:

A capacitor film grading treatment device, comprising an unwinding shaft, a pretreatment unit, a functional deposition unit, a film metallization unit and a winding shaft; wherein, the unwinding shaft and the winding shaft are used to fix the film to be processed; the pretreatment unit is composed of The upper and lower electrode plates are formed, which adopts the form of dielectric barrier discharge, which applies high voltage between the upper and lower electrode plates to excite the working gas to generate low-temperature plasma; the functional deposition unit uses the atomic layer deposition method to introduce precursors in the A functional coating is deposited on the surface of the treated thin film; the thin film metallization unit is used for evaporating metal on the surface of the thin film with the functional coating.

Further, the functional coating is an inorganic oxide coating.

Further, the inorganic oxide coating is Al ₂ O ₃ , AlN or ZnO.

Further, the high-voltage power supply required by the pre-processing unit to excite the low-temperature plasma generated is a high-frequency high-voltage AC power supply, a microsecond pulse power supply, a nanosecond pulse power supply, a microwave power supply, a radio frequency or a DC power supply.

Further, the working gas of the pretreatment unit is selected from air, argon, nitrogen, helium or neon.

Further, the precursors are trimethylaluminum, diethylzinc, triethylamine and water.

Further, the material of the film to be treated is a PP film or a high molecular polymer film.

Further, the material of the high molecular polymer film is polyimide, polytetrafluoroethylene, polyvinylidene fluoride or polystyrene.

The invention also discloses a processing method of the capacitor film grading processing device, which comprises the following steps:

(1) Select the capacitor film with a certain width and thickness as the film to be treated, and fix it on the rewinding reel and the unwinding reel;

(2) Make the film to be treated enter the pretreatment unit, adjust the speed of the rewinding shaft and the unwinding shaft, and select an appropriate speed to make the film to be treated pass through the pretreatment unit; the pretreatment unit adopts a flat electrode structure, and set the appropriate discharge voltage, discharge power and Treatment time, pretreatment of the film to be treated;

(3) The film to be treated is introduced into the functional deposition unit at a certain speed, the precursor is introduced, and the number of deposition cycles is controlled to ensure that a dense and uniform functional coating is deposited on the surface of the film to be treated;

(4) The treated film is introduced into the film metallization unit, and metal is evaporated on the surface of the film.

Beneficial effects:

The invention combines the discharge plasma surface treatment technology and the ALD technology to deposit a functional layer on the film substrate, and perform surface modification on the deposition interface, so as to improve the interface defects, improve the breakdown field strength threshold of the metallized film, and improve the isolation of the metallized film. Self-healing properties. The invention aims at the existing key links of thin film preparation, introduces pretreatment and functional deposition links, has the advantages of simple device structure, convenient operation, continuous grading and the like, and is suitable for large-scale industrial production applications.

Description of drawings

Fig. 1 is a schematic diagram of the capacitor film classification processing device of the present invention.

The reference numbers in the figure are: 1-unwinding reel, 2-film to be processed, 3-pretreatment unit, 4-functional deposition unit, 5-film metallization unit, 6-winding reel.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

As shown in FIG. 1 , the capacitor film classification processing device of the present invention includes an unwinding reel 1 , a pretreatment unit 3 , a functional deposition unit 4 , a film metallization unit 5 and a winding reel 6 .

The pretreatment unit 3 is composed of upper and lower electrode plates, and adopts the form of dielectric barrier discharge (DBD), which applies a high voltage between the upper and lower electrode plates, and uses a high-voltage power supply to excite the working gas to generate low-temperature plasma. The surface is treated to adjust the surface roughness of the film 2 to be treated and improve the adhesion of the film substrate. It utilizes the interaction between the plasma and the thin film substrate to uniformly control the roughness of the thin film substrate. The interaction is primarily a physical etching effect.

The functional deposition unit 4 uses ALD technology to introduce the precursor into the deposition chamber through the gas path, and controls the flow rate, residence time, purging time, deposition cycle times, etc. of the precursor, so that the precursor is alternately circulated through the gas path. In the deposition chamber, a functional coating is deposited on the surface of the film 2 to be processed through a self-limiting chemical reaction, which inhibits the charge injection of the metal layer to the film base material and increases the breakdown field strength threshold of the metallized film. The functional coating is mainly an inorganic oxide coating, such as Al ₂ O ₃ , AlN, ZnO and the like.

Neither the pretreatment unit 3 nor the functional deposition unit 4 will cause damage to the body of the thin film material.

The high-voltage power supply required by the pre-processing unit 3 to generate the excitation plasma can be selected from a high-frequency high-voltage AC power supply, a microsecond pulse power supply, a nanosecond pulse power supply, a microwave power supply, a radio frequency or a DC power supply, and the like.

The working gas required by the pretreatment unit 3 can be selected from air, argon, nitrogen, helium, neon and the like.

The precursors required by the functional deposition unit 4 may be trimethylaluminum, diethylzinc, triethylamine, water, and the like.

The discharge form of the low-temperature plasma is not limited to corona discharge, but can also use the form of dispersion discharge, sliding arc discharge, atmospheric pressure dielectric barrier discharge, and the like.

The material of the film to be treated 2 is not only polypropylene film (PP), but also various high molecular polymer films, such as polyimide (PI), polytetrafluoroethylene (PTFE), polyvinylidene fluoride. (PVDF), polystyrene (PS), etc.

The working process of the present invention is as follows: firstly, the to-be-treated film 2 is pretreated by low-temperature plasma generated by dielectric barrier discharge (DBD) in a specific atmosphere, the surface roughness of the film is uniformized, and the bonding force between the metal layer and the film is increased. Then, select appropriate precursors and reactive gases, and use atomic layer deposition (ALD) to construct a reaction environment with adjustable element ratio, reaction rate and active particle flux, and build a nano-functional layer on the surface of the film to inhibit the metal layer. The charge injection of the film material increases the breakdown field strength threshold of the metallized film and improves the isolation and self-healing performance of the metallized film.

Specifically, the processing method of the capacitor film classification processing device of the present invention comprises the following steps:

(1) Prepare the film 2 to be treated. A capacitor film with a certain width and thickness is selected as the film to be processed, and fixed on the rewinding reel 6 and the unwinding reel 1 .

(2) The pretreatment unit 3 entering the plasma. Adjust the speed of the winding shaft 6 and the unwinding shaft 1, and select a suitable speed to make the film 2 to be processed pass through the pretreatment unit 3. The pretreatment unit 3 adopts a flat electrode structure, and sets appropriate discharge voltage, discharge power and treatment time to pretreat the film 2 to be treated.

(3) Enter the functional deposition unit 4 . The film 2 to be treated is introduced into the functional deposition unit at a certain speed. A specific precursor is introduced, and the number of deposition cycles is controlled to ensure that a dense and uniform deposition coating is formed on the surface of the film 2 to be treated.

(4) Finally, the processed film is introduced into the film metallization unit 5 to complete metal evaporation on the surface of the film.

The following is an example of BOPP film:

Select a BOPP film roll with a width of 120mm and a thickness of 15μm, place the BOPP film to be processed on the unwinding reel 1, and control it to enter the pretreatment unit 3, the functional deposition unit 4, and the film metallization unit 5 in sequence at a certain speed to complete the processing process. . The BOPP film is a biaxially oriented polypropylene film.

Those skilled in the art can easily understand that the above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, etc., All should be included within the protection scope of the present invention.

Claims (9)

1. A capacitor film grading treatment device, characterized in that: it comprises an unwinding shaft, a pretreatment unit, a functional deposition unit, a film metallization unit and a winding shaft; wherein, the unwinding shaft and the winding shaft are used to fix the film to be processed; The pretreatment unit is composed of upper and lower electrode plates, which adopts the form of dielectric barrier discharge, which applies high voltage between the upper and lower electrode plates to excite the working gas to generate low-temperature plasma; the functional deposition unit uses the atomic layer deposition method, A functional coating is deposited on the surface of the thin film to be treated by introducing a precursor; the thin film metallization unit is used for evaporating metal on the surface of the thin film with the functional coating. 2 . The capacitor film grading treatment device according to claim 1 , wherein the functional coating is an inorganic oxide coating. 3 . 3 . The capacitor film grading treatment device according to claim 2 , wherein the inorganic oxide coating is Al ₂ O ₃ , AlN or ZnO. 4 . 4. The capacitor film grading treatment device according to claim 1, wherein the high-voltage power supply required by the pre-processing unit to excite the low-temperature plasma and generate is a high-frequency high-voltage AC power supply, a microsecond pulse power supply, and a nanosecond pulse power supply , microwave power, radio frequency or DC power. 5 . The capacitor film grading treatment device according to claim 1 , wherein the working gas of the pretreatment unit is selected from air, argon, nitrogen, helium or neon. 6 . 6 . The capacitor film grading treatment device according to claim 1 , wherein the precursors are trimethylaluminum, diethylzinc, triethylamine and water. 7 . 7 . The capacitor film grading treatment device according to claim 1 , wherein the material of the film to be treated is PP film or high molecular polymer film. 8 . 8 . The capacitor film grading processing device according to claim 7 , wherein the material of the high molecular polymer film is polyimide, polytetrafluoroethylene, polyvinylidene fluoride or polystyrene. 9 . 9. The processing method of the capacitor film grading processing device according to one of claims 1-8, characterized in that, comprising the following steps: (1) Select the capacitor film with a certain width and thickness as the film to be treated, and fix it on the rewinding reel and the unwinding reel; (2) Make the film to be treated enter the pretreatment unit, adjust the speed of the rewinding shaft and the unwinding shaft, and select an appropriate speed to make the film to be treated pass through the pretreatment unit; the pretreatment unit adopts a flat electrode structure, and set the appropriate discharge voltage, discharge power and Treatment time, pretreatment of the film to be treated; (3) The film to be treated is introduced into the functional deposition unit at a certain speed, the precursor is introduced, and the number of deposition cycles is controlled to ensure that a dense and uniform functional coating is deposited on the surface of the film to be treated; (4) The treated film is introduced into the film metallization unit, and metal is evaporated on the surface of the film.

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