Metallized film and metallized thin film capacitors

Abstract

This utility model discloses a metallized film and a metallized film capacitor. The metallized film includes a dielectric film and a metal plating layer. The metal plating layer is deposited on the dielectric film, and a longitudinal edge without the metal plating layer is formed on one side of the dielectric film. The metal plating layer has transverse gaps and longitudinal gaps spaced apart along the longitudinal direction. The transverse gaps divide the metal plating layer into multiple electrode segments extending longitudinally. Each electrode segment is connected to the other through a longitudinal fuse on the longitudinal gap and a transverse fuse on the transverse gap. The transverse fuse is positioned close to the longitudinal edge, or close to both the longitudinal edge and the longitudinal gap, to prevent moisture from entering the transverse gap from the longitudinal edge. This prevents further self-healing, arcing, and corrosion, improving the moisture resistance of the capacitor.

Description

Technical Field

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

[0002] With the rapid development of metallized film capacitor technology, the requirements for its safety are increasing. Metallized safety films, through a grid structure connected by fuses (divided into lateral and longitudinal fuses), achieve localized isolation in case of failure and are widely used in harsh environments such as high voltage and high temperature. However, in existing technologies, the lateral gaps (slits in the film width direction) of the safety film have significant defects:

[0003] Dissection revealed that the capacitor's self-healing, arcing, and corrosion failures were concentrated in the transverse gap area. Analysis showed that moisture entered the core through the longitudinal edge via the transverse gap, leading to corrosion of the metallized coating and deterioration of the dielectric film under long-term high temperature and pressure.

[0004] In existing designs, there are 0 to 2 horizontal fuses, and most of them adopt a layout of "average horizontal gaps" without directly blocking the water vapor penetration path of the horizontal gaps, resulting in insufficient moisture protection.

[0005] Therefore, it is necessary to develop a metallized film that can effectively isolate water vapor channels in the transverse gaps to improve the reliability and service life of capacitors. Utility Model Content

[0006] This invention aims to at least partially solve one of the technical problems in the aforementioned technologies. To this end, one objective of this invention is to provide a metallized film that, by placing a transverse fuse near the longitudinal edge of the transverse gap, prevents moisture from entering the channel of the transverse gap from the longitudinal edge, thereby preventing further self-healing, arcing, and corrosion, and improving the moisture resistance of the capacitor.

[0007] To achieve the above objectives, this utility model provides a metallization film comprising a dielectric thin film and a metal coating.

[0008] The metal coating is deposited on the dielectric film, and a longitudinal edge without the metal coating is formed on one side of the dielectric film. The metal coating is provided with transverse gaps and longitudinal gaps at intervals along the longitudinal direction. The transverse gaps divide the metal coating into multiple electrode segments extending longitudinally. Each electrode segment is connected to the other through a longitudinal fuse on the longitudinal gap and a transverse fuse on the transverse gap. The transverse fuse is located near the longitudinal edge, or near the longitudinal edge and the longitudinal gap, to prevent moisture from entering the transverse gap from the longitudinal edge.

[0009] According to the metallization film proposed in this embodiment of the present invention, by setting a transverse fuse near the longitudinal edge of the transverse gap, or near the longitudinal edge and the longitudinal gap, moisture is prevented from entering the channel of the transverse gap from the longitudinal edge, thereby preventing further self-healing, arcing, and corrosion, and improving the moisture resistance of the capacitor.

[0010] In addition, the metallized film proposed above according to the embodiments of this utility model may also have the following additional technical features:

[0011] Optionally, the longitudinal gap is set as a rectangle with at least one long side recessed.

[0012] Optionally, the metal coating further includes a longitudinal electrode disposed on the opposite side of the longitudinal edge.

[0013] Optionally, the lateral gap and the longitudinal gap are arranged at an oblique intersection.

[0014] To achieve the above objectives, a second aspect of this utility model provides a metallized film capacitor, which includes a capacitor element formed by staggered stacking and rolling of a first metallized film and a second metallized film, wherein the first metallized film includes the aforementioned metallized film.

[0015] Furthermore, the second metallized film has the same structure as the first metallized film, and the second metallized film and the first metallized film are rotated 180° relative to their overlapping layer. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the first metallization film of a single transverse fuse according to an embodiment of the present invention;

[0017] Figure 2 This is a schematic diagram of the structure of the first metallization film of two transverse fuses according to an embodiment of the present invention;

[0018] Figure 3 This is a cross-sectional view of the first metallized film and the second metallized film according to the embodiments of the present utility model when their structures are identical;

[0019] Figure 4 The diagram shows the structure of the first metallized film and the ordinary metallized film according to the embodiments of the present invention.

[0020] Label Explanation

[0021] 1. Dielectric thin film; 2. Metal coating; 3. Longitudinal edge; 4. Transverse gap; 5. Longitudinal gap; 6. Longitudinal fuse; 7. Longitudinal electrode; 8. Electrode segment; 9. First metallization film a; Second metallization film b. Detailed Implementation

[0022] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0023] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0024] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0025] The following is a reference to the appendix. Figure 1-4 The present invention relates to a metallized film and a metallized thin-film capacitor.

[0026] The metallization film proposed in this embodiment of the utility model includes a dielectric film 1 and a metal coating 2.

[0027] Specifically, the metal coating 2 is deposited on the dielectric film 1, and a longitudinal edge 3 of the undeposited metal coating 2 is formed on one side of the dielectric film 1. The metal coating 2 is arranged with transverse gaps 4 and longitudinal gaps 5 at intervals along the longitudinal direction. The transverse gaps 4 divide the metal coating 2 into multiple electrode segments 9 extending longitudinally. Each electrode segment 9 is connected to the other through a longitudinal fuse 6 on the longitudinal gap 5 and a transverse fuse 7 on the transverse gap 4. The transverse fuse 7 is set close to the longitudinal edge 3, or close to the longitudinal edge 3 and the longitudinal gap 5, so as to prevent moisture from entering the transverse gap 4 from the longitudinal edge 3.

[0028] In other words, this utility model defines the film width direction as transverse, and the corresponding gap is called transverse gap 4; the direction orthogonal to the transverse is longitudinal, and the corresponding gap is called longitudinal gap 5. The transverse gaps 4 in each column are repeated at equal intervals along the longitudinal direction, intersecting with the longitudinal gaps 5 to form longitudinal electrodes 8 and electrode divisions 9; a vapor-deposited metal layer is provided inside the longitudinal electrodes 8 and electrode divisions 9, and no vapor-deposited metal layer is provided on the longitudinal edge 3. The vapor-deposited metal provided at the longitudinal gap 5, connecting the electrode divisions 9 and the longitudinal electrodes 8, is the longitudinal fuse 6, and the vapor-deposited metal provided at the transverse gap 4, connecting the two electrode divisions 9, is the transverse fuse 7. The transverse fuse 7 is provided on the transverse gap 4 located near the longitudinal edge 3, or on the transverse gap 4 located near both the longitudinal edge 3 and the longitudinal gap 5. This can effectively prevent moisture from entering the transverse gap 4 from the longitudinal edge 3, thereby preventing further self-healing, arcing, and corrosion, and improving the moisture resistance of the capacitor. The transverse gap 4 and the longitudinal gap 5 can be long rectangular strips, and the transverse gap 4 and the longitudinal gap 5 intersect and connect. A plurality of longitudinal gaps 5 can be provided in an electrode dividing part 9 at intervals.

[0029] Therefore, by installing a transverse fuse 7 on the transverse gap 4 near the longitudinal edge 3, or near the longitudinal edge 3 and the longitudinal gap 5, moisture is prevented from entering the channel of the transverse gap 4 from the longitudinal edge 3, thereby preventing further self-healing, arcing, and corrosion, and improving the moisture resistance of the capacitor.

[0030] Optionally, the longitudinal gap 5 is set as a rectangle with at least one long side concave. Understandably, by setting the longitudinal gap 5 as a rectangle with at least one long side concave, i.e., a semi-I-shape or an I-shape, the fuse length can be kept constant, the performance of the electrode segment 9 can be not affected, and the effective area of ​​the capacitor can be increased, thereby improving the utilization rate of the metallization film. The area of ​​the longitudinal gap 5 is reduced, the consumption of shielding oil required is reduced, and the evaporation speed of the metallization film is increased.

[0031] Optionally, the metal plating 2 further includes a longitudinal electrode 8, which is disposed on the opposite side of the longitudinal edge 3. Understandably, as the main conduction channel for longitudinal current, it is connected to the electrode segment 9 via a longitudinal fuse 6 to form an ordered conductive network. The width of the longitudinal electrode 8 may be greater than the width of the longitudinal edge 3.

[0032] Optionally, the transverse gap 4 and the longitudinal gap 5 are arranged at an angle to intersect. Understandably, this angled intersection of the transverse gap 4 and the longitudinal gap 5 forms a T-shaped structure, making the connection between the transverse gap 4 and the longitudinal gap 5 more compact and creating a three-dimensional grid. When a square fails, the fuses in the transverse and longitudinal gaps 5 can melt simultaneously or sequentially, achieving bidirectional isolation and improving the fault response sensitivity of the metallized film. The downward angle between the transverse gap 4 and the longitudinal gap 5 can be 70° to 85°.

[0033] Furthermore, this utility model also proposes a metallized film capacitor, which includes a capacitor element formed by staggered stacking and winding of a first metallized film a and a second metallized film b. The first metallized film a includes the aforementioned metallized film. It is understood that the staggered stacking and winding of the first metallized film a and the second metallized film b can reduce capacitance deviation and improve the high-frequency performance of the capacitor, thereby ensuring stable capacitor performance. The second metallized film b can be a common metallized film (without a metal mesh) formed by vapor deposition of a dielectric film and a metal plating layer, and having longitudinal edges, or it can be a safety film with the same structure as the first metallized film a. When the first metallized film a is used in conjunction with a common metallized film, the number of transverse fuses 7 on the first metallized film a can be set to two.

[0034] Specifically, the second metallized film b has the same structure as the first metallized film a, and the second metallized film b and the first metallized film a are rotated 180° relative to their overlapping layer. Understandably, since the second metallized film b has the same structure as the first metallized film b, before winding, the first metallized film a is rotated 180° relative to the second metallized film b along their overlapping layer, so that the longitudinal edges of both are located on the left and right sides of the film width direction, and the metal coating 2 of both faces the same direction, before staggered winding. This arrangement improves the edge electric field distribution, prevents partial discharge, optimizes mechanical properties, enhances winding stability, and ultimately achieves high reliability, long lifespan, and stable performance of the capacitor.

[0035] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0037] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0038] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0039] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0040] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A metallized film, characterized in that: Including dielectric thin films and metal coatings; The metal coating is deposited on the dielectric film, and a longitudinal edge without the metal coating is formed on one side of the dielectric film. The metal coating is spaced with transverse gaps and longitudinal gaps along the longitudinal direction. The transverse gaps divide the metal coating into multiple electrode segments extending longitudinally. Each electrode segment is connected to the other through a longitudinal fuse on the longitudinal gap and a transverse fuse on the transverse gap. The transverse fuse is located near the longitudinal edge or near both the longitudinal edge and the longitudinal gap to prevent moisture from entering the transverse gap from the longitudinal edge.

2. The metallized film as described in claim 1, characterized in that, The longitudinal gap is set as a rectangle with at least one long side concave.

3. The metallized film as described in claim 1, characterized in that, The metal coating also includes a longitudinal electrode, which is disposed on the opposite side of the longitudinal edge.

4. The metallized film as described in claim 1, characterized in that, The lateral gap and the longitudinal gap are set at an angle to intersect.

5. A metallized thin-film capacitor, characterized in that, The metallized film capacitor includes a capacitor element, which is formed by staggered stacking and rolling of a first metallized film and a second metallized film, wherein the first metallized film includes the metallized film as described in any one of claims 1 to 4.

6. The metallized thin-film capacitor as claimed in claim 5, characterized in that, The second metallized film has the same structure as the first metallized film, and the second metallized film and the first metallized film are rotated 180° relative to their overlapping layer.

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