A high voltage withstanding metallized film capacitor

Abstract

This utility model discloses a high-voltage-resistant metallized film capacitor, belonging to the field of capacitor technology. It includes a capacitor casing, a capacitor core disposed inside the casing, an encapsulation layer between the casing and the core, a top safety film at the top of the core, a bottom safety film at the bottom, several layers of metallized film between the top and bottom safety films, a protective film between the metallized films, and gold-plated layers at both ends of the core, connected to the leads. This utility model, employing the above structure, improves the voltage withstand performance of the metallized film capacitor while ensuring capacitance.

Description

Technical Field

[0001] This utility model relates to the field of capacitor technology, and in particular to a high-voltage metallized thin-film capacitor. Background Technology

[0002] Capacitors are components that store electrical charge and energy. In circuits, they perform various functions such as DC blocking, AC passing, filtering, coupling, and bypassing. Metallized film capacitors, due to their self-healing properties, miniaturization advantages, and high-frequency performance, are widely used in power electronics, new energy, and industrial control. With the increasing industry demands for high voltage and high reliability, ensuring the high voltage withstand performance of metallized film capacitors is becoming increasingly important. The voltage withstand performance of metallized film capacitors limits their application in high-voltage scenarios, necessitating the development of a high-voltage-withstanding metallized film capacitor. Utility Model Content

[0003] The purpose of this invention is to provide a high-voltage metallized film capacitor that improves the voltage withstand performance of the metallized film capacitor while ensuring capacitance.

[0004] To achieve the above objectives, this utility model provides a high-voltage metallized film capacitor, comprising a capacitor housing, a capacitor core disposed inside the capacitor housing, an encapsulation layer disposed between the capacitor housing and the capacitor core, a top safety film disposed at the top end of the capacitor core, a bottom safety film disposed at the bottom end of the capacitor core, a plurality of metallized films disposed between the top and bottom safety films, a protective film disposed between the metallized films, and gold sputtering layers disposed at the left and right ends of the capacitor core, the gold sputtering layers being connected to the leads.

[0005] Preferably, the encapsulation layer is specifically configured as a thermally conductive epoxy resin, and the encapsulation layer fixes the capacitor core inside the capacitor casing.

[0006] Preferably, the top safety film and the bottom safety film are specifically made of polyester film, and the protective film is specifically made of polypropylene film, with the top safety film, the protective film and the bottom safety film aligned at their left and right ends.

[0007] Preferably, the left end of the odd-numbered metallized film is aligned with the top safety film, and the right end extends beyond the right end of the top safety film.

[0008] Preferably, the right end of the even-numbered metallized film is aligned with the top safety film, and the left end extends beyond the left end of the top safety film.

[0009] Preferably, the metallized film includes a plastic film and a metal coating. The plastic film is specifically a polyester film, and the metal coating is specifically a zinc-aluminum composite metal layer. The metal coating is deposited on the upper and lower surfaces of the plastic film in evenly spaced blocks, and an edge is left at the end of the metallized film that is aligned with the top safety film.

[0010] Preferably, the interval length of the metal coating block vapor deposition, the length of the edge left by the metallized film, and the length of the metallized film extending beyond the top safety film are equal.

[0011] Preferably, the gold-plated layer is specifically configured as a zinc-tin alloy layer with a thickness of 8-15 micrometers.

[0012] Therefore, the present invention employs the above-mentioned high-voltage metallized film capacitor, which has the following advantages: (1) In this utility model, two safety membranes, a top safety membrane and a bottom safety membrane, are provided, which provides a more reliable pressure buffering mechanism. If one of the safety membranes fails to function, the other safety membrane can provide protection.

[0013] (2) In this utility model, the metal coating edge design of the metallized film can reduce the dielectric loss of the capacitor, which is beneficial to suppress the fluctuation of the capacitor capacity and further improves the voltage resistance and stability of the capacitor.

[0014] (3) In this utility model, a protective film is set between the metallized films, which increases the electrical distance between adjacent metallized films. The intervention of the protective film makes the electric field strength more uniform, avoids breakdown caused by local electric field concentration, and improves the voltage withstand capability of the capacitor.

[0015] (4) In this utility model, the metal coating of the metallized film is uniformly spaced and deposited on the surface of the plastic film. When a breakdown circuit occurs, the metal coating can achieve self-healing more efficiently. The metal coating around the breakdown point evaporates rapidly under the action of the electric arc, forming an insulating isolation area. Due to the segmented design, the breakdown discharge range and time can be effectively limited. The self-healing process has little impact on the surrounding area, and the self-healing sensitivity is high, which improves the self-healing performance and enhances the withstand voltage and safety.

[0016] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the internal structure of a high-voltage metallized thin-film capacitor according to the present invention. Reference numerals: 1. Capacitor casing; 2. Encapsulation layer; 3. Capacitor core; 4. Top safety film; 5. Plastic film; 6. Metal plating; 7. Metallized film; 8. Protective film; 9. Bottom safety film; 10. Gold plating layer; 11. Lead. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can be arranged and designed in various different configurations. Specific model specifications need to be selected and determined according to the actual specifications of the device, etc. The specific selection calculation method adopts existing technology in the art, and therefore will not be described in detail.

[0019] Example like Figure 1 As shown, this utility model provides a high-voltage metallized film capacitor, including a capacitor shell 1, a capacitor core 3 disposed inside the capacitor shell 1, an encapsulation layer 2 disposed between the capacitor shell 1 and the capacitor core 3, the encapsulation layer 2 being specifically made of thermally conductive epoxy resin, the encapsulation layer 2 fixing the capacitor core 3 inside the capacitor shell 1, a top safety film 4 disposed at the top end inside the capacitor core 3, a bottom safety film 9 disposed at the bottom end inside the capacitor core 3, several layers of metallized film 7 disposed between the top safety film 4 and the bottom safety film 9, a protective film 8 disposed between the metallized film 7, the top safety film 4 and the bottom safety film 9 being specifically made of polyester film, the protective film 8 being specifically made of polypropylene film, the top safety film 4, the protective film 8 and the bottom safety film 9 being aligned at their left and right ends, a gold sputtering layer 10 disposed at both ends of the capacitor core 3, the gold sputtering layer 10 being connected to the pins 11, the gold sputtering layer 10 being specifically made of zinc-tin alloy layer with a thickness of 8-15 micrometers.

[0020] The left end of the odd-numbered metallized film 7 is aligned with the top safety film 4, and the right end extends beyond the right end of the top safety film 4. The right end of the even-numbered metallized film 7 is aligned with the top safety film 4, and the left end extends beyond the left end of the top safety film 4.

[0021] The metallized film 7 includes a plastic film 5 and a metal coating 6. The plastic film 5 is specifically a polyester film, and the metal coating 6 is specifically a zinc-aluminum composite metal layer. The metal coating 6 is deposited in evenly spaced blocks on the upper and lower surfaces of the plastic film 5. An edge is left at the end of the metallized film 7 that aligns with the top safety film 4; no metal coating is applied to this edge to prevent it from being broken down due to concentrated electric field. The interval length of the metal coating 6 during block deposition, the length of the edge left by the metallized film 7, and the length of the metallized film 7 extending beyond the top safety film 4 are equal.

[0022] A protective film 8 is placed between the metallized films 7, which increases the electrical distance between adjacent metallized films 7. The intervention of the protective film 8 makes the electric field intensity more uniform, avoids breakdown caused by local electric field concentration, and improves the voltage withstand capability of the capacitor.

[0023] The metal plating 6 of the metallized thin film 7 is uniformly and segmented on the surface of the plastic film 5. When a circuit breakdown occurs, the metal plating 6 can achieve self-healing more efficiently. The metal plating 6 around the breakdown point evaporates rapidly under the action of the electric arc, forming an insulating isolation area. Due to the segmented design, the self-healing process has little impact on the surrounding area and can quickly restore the insulation state. Moreover, each segment is independent and has high self-healing sensitivity, which can avoid large-area continuous breakdown and burning. It can effectively limit the breakdown discharge range and time, improve self-healing performance, and improve withstand voltage and safety.

[0024] Therefore, this utility model adopts a high-voltage metallized film capacitor, which improves the voltage withstand performance of the metallized film capacitor while ensuring capacitance.

[0025] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solution of this utility model, and these modifications or equivalent substitutions cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of this utility model.

Claims

1. A high voltage metallized film capacitor characterized by: The capacitor includes a capacitor housing, inside which a capacitor core is disposed. An encapsulation layer is disposed between the capacitor housing and the capacitor core. A top safety film is disposed at the top end of the capacitor core, and a bottom safety film is disposed at the bottom end of the capacitor core. Several metallized thin films are disposed between the top and bottom safety films, and a protective film is disposed between the metallized thin films. Gold sputtering layers are disposed at both ends of the capacitor core, and the gold sputtering layers are connected to the leads.

2. The high-voltage metallized film capacitor according to claim 1, characterized in that: The encapsulation layer is specifically configured as a thermally conductive epoxy resin, which fixes the capacitor core inside the capacitor casing.

3. A high-voltage metallized film capacitor according to claim 1, characterized in that: The top safety film and the bottom safety film are specifically made of polyester film, and the protective film is specifically made of polypropylene film. The top safety film, the protective film and the bottom safety film are aligned at their left and right ends.

4. A high-voltage metallized film capacitor according to claim 1, characterized in that: The left end of the odd-numbered metallized film is aligned with the top safety film, and the right end extends beyond the right end of the top safety film.

5. A high-voltage metallized film capacitor according to claim 4, characterized in that: The right end of the even-numbered metallized film is aligned with the top safety film, and the left end extends beyond the left end of the top safety film.

6. A high-voltage metallized film capacitor according to claim 5, characterized in that: The metallized film includes a plastic film and a metal coating. The plastic film is specifically a polyester film, and the metal coating is specifically a zinc-aluminum composite metal layer. The metal coating is deposited on the upper and lower surfaces of the plastic film in evenly spaced blocks, and an edge is left at one end of the metallized film that is aligned with the top safety film.

7. A high-voltage metallized film capacitor according to claim 6, characterized in that: The interval length of the metal coating layer by evaporation, the length of the edge left by the metallized film, and the length of the metallized film extending beyond the top safety film are equal.

8. A high-voltage metallized film capacitor according to claim 1, characterized in that: The gold-plated layer is specifically a zinc-tin alloy layer with a thickness of 8-15 micrometers.

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