High-temperature-resistant metalized polypropylene film dielectric capacitor
By evaporating metal aluminum and zinc layers on polypropylene film capacitors, combined with silicone oil filling and tin-plated copper connection, the problem of decreasing breakdown strength of traditional polypropylene capacitors at high temperatures is solved, achieving high temperature resistance, low loss and Safe and reliable capacitor performance.
Patent Information
- Application Number
- CN202411300027.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-18
- Publication Date
- 2025-01-07
AI Technical Summary
Traditional polypropylene film capacitors have decreased breakdown strength and increased leakage loss in high temperature environments, resulting in too fast internal temperature rise, which may cause the capacitor to swell or explode, and cannot meet the safety and stability needs in the current high temperature environment.
Using high temperature resistant metallized polypropylene film capacitor, the active area of metal aluminum is vacuum deposition on the polypropylene film, and the pure zinc thickened area is evaporated at the edge of the active area, combined with PMX-200 series silicone oil filling and tin plating The copper is connected in charge to improve the heat dissipation and temperature resistance of the capacitor.
It realizes the high temperature resistance, low shrinkage rate and good moisture resistance of the capacitor, extends the service life, reduces temperature rise and loss, and improves the safety and reliability of the capacitor.
Smart Images
Figure CN119274973A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of film capacitor manufacturing, and in particular to a high-temperature resistant metallized polypropylene film dielectric capacitor. Background Art
[0002] As the basic building block of the circuit system, film capacitors have shown extensive application potential in many scientific and technological fields with their excellent temperature-frequency stability and low impedance characteristics. The application range is wide, spanning the diversified technology frontiers such as radio and television, communications, computer information, aerospace, precision measurement, power transmission, military electronics, military equipment, automation control and medical equipment. It is particularly worth mentioning that in the emerging field of hybrid vehicles, it has demonstrated its unique technical value and achieved extensive coverage and in-depth application of technical performance.
[0003] Metallized polypropylene film capacitors are a type of highly efficient organic film capacitors among film capacitors. They are made through the perfect combination of polypropylene film substrate and vacuum-evaporated metal layer, and are processed through winding, gold spraying and other processes. With its advantages such as high breakdown field strength, low dielectric and power loss, low operating temperature rise and ultra-long service life, it has become the preferred capacitor in the field of industrial frequency and high-voltage power. Its excellent capacity-to-volume ratio promotes the miniaturization of the product, while its self-healing characteristics provide a guarantee for the safety of the operating system. In addition, it has excellent processability, allowing the shape to be flexibly customized according to actual needs, meeting the diverse needs of high-standard application scenarios such as power facilities, electrical equipment, electric locomotives and military equipment.
[0004] However, in the face of the rapid development of electronic information, electric power industry and military equipment, film capacitors are facing unprecedented challenges. Large capacity, miniaturization and high safety and reliability have become new technical pursuits, and more stringent requirements have been put forward for the volume, temperature resistance and reliability of film capacitors. In particular, the upper temperature limit of traditional polypropylene capacitors is limited to about 110°C, which can hardly meet the high standard requirements for the heat resistance of dielectric materials in the current high temperature environment. When the operating temperature exceeds 85°C, the breakdown strength of polypropylene film capacitors will drop sharply, and the leakage loss will increase sharply. Long-term operation can easily lead to excessive internal temperature rise, which will cause the capacitor to swell or even explode, fail or even cause safety accidents, seriously threatening the stability and safety of the entire equipment system. Therefore, how to provide a small-volume, high-temperature-resistant, and low-shrinkage polypropylene film capacitor is an urgent need to break through the bottleneck and ensure the safety and stability of the circuit.
[0005] In view of this, the present invention is proposed. Summary of the invention
[0006] The purpose of the present invention is to provide a high temperature resistant metallized polypropylene film dielectric capacitor, which has good heat dissipation performance, excellent temperature resistance, small size and low shrinkage, and can ensure the moisture resistance of chip-type solid electrolyte tantalum capacitors, thereby solving the problems of poor moisture resistance of existing tantalum capacitors, deterioration of electrical performance after absorbing water vapor, and cracking of epoxy shells during high temperature welding.
[0007] The objective of the present invention is achieved through the following technical solutions:
[0008] A high temperature resistant metallized polypropylene film dielectric capacitor comprises: a shell, in which at least one capacitor core is arranged, and a lead terminal electrically connected to the capacitor core is arranged at the upper end of the shell, the capacitor core is a film capacitor core comprising a high temperature resistant metallized polypropylene film, the bottom of the high temperature resistant metallized polypropylene film is a polypropylene film, a layer of metal aluminum is vacuum evaporated on the polypropylene film as an active area of the electrode, and the square resistance of the active area is 6 to 10Ω / □; a thickened area of pure zinc is evaporated on the edge of the active area, and the square resistance of the thickened area is 1 to 3Ω / □.
[0009] Preferably, in the above capacitor, the edge of the active area is in the form of wave cutting and is set as a zinc-aluminum composite distillation thickening area.
[0010] Preferably, in the above capacitor, the width of the active area is 15 to 45 mm, and the width of the thickened area is 5 to 15 mm.
[0011] Preferably, in the above capacitor, there are two or more capacitor cores, and each capacitor core is connected in parallel.
[0012] Preferably, in the above capacitor, the capacitor core and the lead-out terminal, and each capacitor core are electrically connected by tin-plated copper.
[0013] Preferably, in the above capacitors, each capacitor core is a structure that is encapsulated once using a plastic cup inner shell and an explosion-proof module.
[0014] Preferably, in the above capacitor, the shell is a shell made by milling 6061 aviation aluminum, and reinforcing ribs are provided on both sides of the shell.
[0015] Preferably, in the above capacitor, bosses and mounting holes are provided on both sides of the shell.
[0016] Preferably, in the above capacitor, the inside of the shell is filled with PMX-200 series silicone oil outside each capacitor core.
[0017] Preferably, in the above-mentioned capacitor, the lead terminal is fixed to the upper part of the shell by bolts, a porcelain bottle insulator for insulation is arranged at the lower part of the lead terminal, the porcelain bottle insulator is clamped between the lead terminal and the shell, and the bottom of the lead terminal in the shell is connected to the tin-plated copper strip electrode by soldering.
[0018] Compared with the prior art, the high temperature resistant metallized polypropylene film dielectric capacitor provided by the present invention has the following beneficial effects:
[0019] The capacitor core including the high temperature resistant metallized polypropylene film is used. Since the high temperature resistant metallized polypropylene film has an active area and a thickened area as an electrode, the capacitor core has high voltage resistance, low loss, strong current impact bearing ability, low temperature rise, small equivalent series resistance of the capacitor itself, and strong anti-oxidation ability. At the same time, the capacitor of the present invention has good safety performance, long service life, easy storage, and low cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.
[0021] Figure 1 A schematic diagram of the internal structure of a high temperature resistant metallized polypropylene film dielectric capacitor provided in an embodiment of the present invention.
[0022] Figure 2 A schematic structural diagram of a metallized polypropylene film of a high temperature resistant metallized polypropylene film dielectric capacitor provided in an embodiment of the present invention.
[0023] Figure 3 for Figure 1 Side view of a high temperature resistant metallized polypropylene film dielectric capacitor.
[0024] Figure 4 for Figure 1 Top view of a high temperature resistant metallized polypropylene film dielectric capacitor.
[0025] In the figure, 1-polypropylene film; 2-active area; 3-thickening area; 4-porcelain bottle insulator; 5-discharge resistor; 6-crimping seal; 7-nut crimping; 8-insulating plate; 9-grounding terminal; 10-plastic cup; 11-explosion-proof module; 12-capacitor core; 13-lead terminal; 14-housing. DETAILED DESCRIPTION
[0026] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in combination with the specific content of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, which does not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.
[0027] First, the terms that may be used in this article are explained as follows:
[0028] The term “and / or” means that either or both of them can be realized at the same time. For example, X and / or Y means both “X” or “Y” and “X and Y”.
[0029] The terms "include", "comprises", "contains", "has" or other descriptions with similar semantics should be interpreted as non-exclusive inclusion. For example, including certain technical feature elements (such as raw materials, components, ingredients, carriers, dosage forms, materials, dimensions, parts, components, mechanisms, devices, steps, procedures, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products or products, etc.) should be interpreted as including not only certain technical feature elements explicitly listed, but also other technical feature elements known in the art that are not explicitly listed.
[0030] The term "consisting of..." means excluding any technical feature elements not explicitly listed. If this term is used in a claim, it will make the claim closed, so that it does not contain technical feature elements other than the technical feature elements explicitly listed, except for the conventional impurities related to them. If this term only appears in a clause of a claim, it only limits the elements explicitly listed in the clause, and the elements recorded in other clauses are not excluded from the overall claim.
[0031] Unless otherwise specified or limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this article can be understood according to specific circumstances.
[0032] When concentration, temperature, pressure, size or other parameters are expressed in the form of a numerical range, the numerical range should be understood to specifically disclose all ranges formed by the pairing of any upper limit, lower limit, and preferred value in the numerical range, regardless of whether the range is explicitly stated; for example, if a numerical range of "2 to 8" is stated, the numerical range should be interpreted as including ranges such as "2 to 7", "2 to 6", "5 to 7", "3 to 4 and 6 to 7", "3 to 5 and 7", "2 and 5 to 7", etc. Unless otherwise specified, the numerical ranges stated herein include both their end values and all integers and fractions within the numerical range.
[0033] The scheme provided by the present invention is described in detail below. The contents not described in detail in the embodiments of the present invention belong to the prior art known to professionals in the field. If the specific conditions are not specified in the embodiments of the present invention, they are carried out according to the conventional conditions in the field or the conditions recommended by the manufacturer. If the manufacturers are not specified in the reagents or instruments used in the embodiments of the present invention, they are all conventional products that can be purchased commercially.
[0034] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, an embodiment of the present invention provides a capacitor with good heat dissipation performance and containing a high-temperature resistant metallized polypropylene film, including a shell, a lead terminal and at least one capacitor core, wherein the capacitor core includes a high-temperature resistant metallized polypropylene film, which has better temperature resistance than conventional polypropylene film, and the polypropylene film is evaporated with a layer of metal aluminum as an active area of the electrode under a high vacuum environment, and the square resistance of the active area is controlled to be 6-10Ω / □; the edge of the active area is a wave-cut structure, and the upper edge of the aluminum active area is a thickened area of zinc distillation, which improves the oxidation resistance of the metal layer, and the square resistance of the thickened area is controlled to be 1-3Ω / □; if multiple capacitor cores are used, the series-parallel connection mode of the multiple capacitor cores is selected according to the required voltage, capacity and shell size of the capacitor.
[0035] Preferably, the width of the active area of the metallized polypropylene film used in the capacitor is 15 to 45 mm, and the width of the thickened area is 5 to 10 mm. A layer of pure zinc is thickened and evaporated at the edge of the active area to form the thickened area, so that the capacitor has high voltage resistance, low loss, strong current impact resistance, low temperature rise, small equivalent series resistance of the capacitor itself, and strong anti-oxidation ability.
[0036] Preferably, in the above-mentioned capacitor, a single capacitor core or a plurality of capacitor cores are connected in parallel inside the shell, and a 0.2-0.5 mm thick tin-plated copper strip is used to connect the capacitor core to the lead-out terminal and between each capacitor core in parallel. The tin-plated copper strip connection has the advantages of low heat generation and strong overcurrent capacity, which effectively improves the heating and heat dissipation of the capacitor core.
[0037] Preferably, in the above capacitor, each capacitor core adopts a structure of one-time packaging using a plastic cup inner shell and an explosion-proof module to ensure the insulation performance and use safety between the outer shell and the electrode of each capacitor core.
[0038] Preferably, in the above capacitor, the shell is made of 6061 aviation aluminum by milling, with high processing accuracy, precise mounting holes, and beautiful appearance, and is suitable for high-precision occasions such as military equipment. The side of the shell is provided with reinforcing ribs to enhance the hardness of the shell and the effective heat dissipation area.
[0039] Preferably, in the above capacitor, PMX-200 series silicone oil is used as an impregnant or filler inside the shell, with its excellent electrical insulation performance, thermal stability, chemical stability and low surface tension, etc., to improve the insulation capacity of the capacitor, reduce losses, improve temperature characteristics, etc. By filling with silicone oil, the performance of the capacitor can be made more stable and reliable, the heat inside the product can be effectively conducted out, the temperature rise inside the product is reduced, and the reliability and life of the product are improved. The shell crimping seal does not leak, saving costs.
[0040] Preferably, in the above capacitor, bosses and mounting positioning holes are provided on both sides of the shell to facilitate the fixed installation of the product or the insertion of rivet nuts.
[0041] Preferably, in the above capacitor, the lead-out terminal is led out by bolts or tinned copper welding pieces, which is convenient for use and installation, and has strong installation firmness. The bottom of the lead-out terminal is insulated from the shell by a porcelain bottle insulator, and is connected to the tinned copper strip electrode by soldering, which has high welding strength, small internal resistance loss, and saves material and labor costs.
[0042] In order to more clearly demonstrate the technical solution and technical effects provided by the present invention, the solution provided by the embodiment of the present invention is described in detail with specific embodiments below.
[0043] Example 1
[0044] The embodiment of the present invention provides a high temperature resistant metallized polypropylene film dielectric capacitor, such as Figure 1As shown, it includes: a shell, a lead terminal and a plurality of capacitor cores, the plurality of capacitor cores are connected in a triangular connection mode, each capacitor core adopts a film capacitor core including a high-temperature resistant metallized polypropylene film, the bottom of the high-temperature resistant metallized polypropylene film is a polypropylene film, on which a layer of metal aluminum is evaporated under a high vacuum environment as an active area of the electrode, and the square resistance of the active area is controlled to be 6-10Ω / □; a layer of pure zinc is thickened and evaporated at the edge of the active area to form a thickened area, and the square resistance of the thickened area is controlled to be 1-3Ω / □;
[0045] A layer of metal aluminum is evaporated in a high vacuum environment as the active area of the electrode, and the square resistance of the active area is controlled to be 6-10Ω / □; the edge of the active area adopts a wave-cutting form, with the aluminum as the active area at the bottom and the zinc as the thickened area at the top of the composite structure. This method improves the oxidation resistance of the metal layer, and the square resistance of the thickened area is controlled to be 1-3Ω / □; in this embodiment, the width of the active area 2 is 15-25mm, and the width of the thickened area 3 is 5-10mm. Under the same process conditions, the high temperature resistant metallized polypropylene film of this embodiment has a temperature resistance 20°C to 25°C higher than that of ordinary polypropylene film, a withstand voltage 7.5% to 15% higher at 105°C, and a 24-hour aging qualified rate 25% to 30% higher; the withstand voltage is 18% to 26% higher at 125°C, and the 24-hour aging qualified rate is 60% to 72% higher; the design of zinc thickening, widening vapor deposition and wave cutting is adopted, the tin-zinc alloy sprayed on the end face of the capacitor core is firmly combined with the metal zinc coating in the thickened area of the high temperature resistant metallized polypropylene film, the loss is small, the contact resistance is low, the ability to withstand effective current and pulse current impact is strong, the temperature rise is low, and the antioxidant ability is strong.
[0046] In this embodiment, a 0.2 mm tinned copper strip triangular connection mode is adopted between each capacitor core and the lead-out electrode, which has a strong ability to withstand large currents and generates little heat, thereby effectively improving the heating and heat dissipation problems of the capacitor core.
[0047] In this embodiment, a discharge resistor is connected in parallel between the two electrodes of each capacitor core for failure protection, thereby ensuring safety and reliability.
[0048] In this embodiment, each capacitor core is packaged once by a plastic cup inner shell and an explosion-proof module to ensure insulation performance between the pole shells and safety in use.
[0049] In this embodiment, the shell is made of 6061 aviation aluminum by milling, with high processing accuracy, precise mounting holes, and beautiful appearance. It is suitable for high-precision occasions such as military equipment. The side of the shell is provided with reinforcing ribs to enhance the hardness of the shell and the effective heat dissipation area.
[0050] In this embodiment, the shell uses PMX-200 series silicone oil as an impregnating agent or filler inside the shell, with its excellent electrical insulation performance, thermal stability, chemical stability and low surface tension, etc., to improve the dielectric constant of the capacitor, reduce losses, improve temperature characteristics, etc. By filling with silicone oil, the performance of the capacitor can be made more stable and reliable, the heat inside the product can be effectively conducted out, the temperature rise inside the product is reduced, and the reliability and life of the product are improved. The shell curling seal does not leak, saving costs.
[0051] In this embodiment, bosses and mounting positioning holes are provided on both sides of the shell to facilitate the fixed installation of the product or the insertion of rivet nuts.
[0052] In this embodiment, the lead-out terminal is led out by bolts, which is convenient for use and installation, and has strong installation firmness. The bottom of the lead-out terminal is insulated with a porcelain bottle insulator and connected to the tinned copper strip electrode by soldering, which has high welding strength, small internal resistance loss, and saves material and labor costs.
[0053] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims. The information disclosed in the background technology section of this article is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or in any form that the information constitutes prior art known to those skilled in the art.
Claims
1. A high temperature resistant metallized polypropylene film dielectric capacitor, comprising: A shell, in which at least one capacitor core is arranged, and a lead terminal electrically connected to the capacitor core is arranged at the upper end of the shell, characterized in that the capacitor core is a film capacitor core including a high-temperature resistant metallized polypropylene film, the bottom of the high-temperature resistant metallized polypropylene film is a polypropylene film, a layer of metal aluminum is vacuum-evaporated on the polypropylene film as an active area of the electrode, and the square resistance of the active area is 6 to 10Ω / □; a thickened area of pure zinc is evaporated on the edge of the active area, and the square resistance of the thickened area is 1 to 3Ω / □.
2. The high temperature resistant metallized polypropylene film dielectric capacitor according to claim 1, characterized in that: The edge of the active area is a wave-cut structure, and the upper edge of the aluminum active area is a thickened area for zinc distillation.
3. The high temperature resistant metallized polypropylene film dielectric capacitor according to claim 1 or 2, characterized in that: The width of the active area is 15 to 45 mm, and the width of the thickened area is 5 to 15 mm.
4. The high temperature resistant metallized polypropylene film dielectric capacitor according to claim 1, characterized in that: There are more than two capacitor cores, and each capacitor core is connected in parallel.
5. The high temperature resistant metallized polypropylene film dielectric capacitor according to claim 1, characterized in that: The capacitor core and the lead-out terminal, as well as each capacitor core, are electrically connected by tin-plated copper.
6. The high temperature resistant metallized polypropylene film dielectric capacitor according to claim 1 or 2, characterized in that: Each capacitor core is a structure that is encapsulated once using a plastic cup inner shell and an explosion-proof module.
7. The high temperature resistant metallized polypropylene film dielectric capacitor according to claim 1 or 2, characterized in that: The shell is a shell made of 6061 aviation aluminum by milling, and reinforcing ribs are arranged on both sides of the shell.
8. The high temperature resistant metallized polypropylene film dielectric capacitor according to claim 1 or 2, characterized in that: Bosses and mounting holes are provided on both sides of the shell.
9. The high temperature resistant metallized polypropylene film dielectric capacitor according to claim 1 or 2, characterized in that: The inside of the shell is filled with PMX-200 series silicone oil outside each capacitor core.
10. The high temperature resistant metallized polypropylene film dielectric capacitor according to claim 1 or 2, characterized in that: The lead-out terminal is fixed to the upper part of the shell by bolts, a porcelain bottle insulator for insulation is arranged at the lower part of the lead-out terminal, and the porcelain bottle insulator is clamped between the lead-out terminal and the shell. The bottom of the lead-out terminal in the shell is connected to the tinned copper strip electrode by soldering.