Thin film capacitor
By designing multi-order continuous grid cells in the metal plating of film capacitors and connecting through fuses, the problem of insufficient self-healing isolation of electrical weakness is solved, and the safety and working life of the capacitor are improved.
Patent Information
- Application Number
- CN202421021818.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-11
- Publication Date
- 2025-04-15
- Estimated Expiration
- 2034-05-11
AI Technical Summary
When metallized film capacitors occur, insufficient self-healing isolation occurs, resulting in insufficient safety factor of the capacitor. In the pursuit of higher performance, the structure of the grid cell leads to capacitance loss and reduced working life.
A film capacitor is designed, and the metal coating comprises at least two orders of continuous repeating grid cells extending in the longitudinal direction, the grid cells are separated by an insulating gap and communicated by a fuse, and the transverse width of the first order grid cells connected by a left edge is smaller than the transverse width of the other order grid cells.
Through this design, the metallized film can provide appropriate self-healing energy when an electrical weakness occurs, reduce the reduction of the capacity area after self-healing, and improve the safety and working life of the capacitor.
Smart Images
Figure CN222762810U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of capacitors, in particular to a film capacitor. Background Art
[0002] Metallized film capacitors are increasingly used in industrial control, new energy, automotive electronics, rail transit, power grids and other fields. At the same time, the failure safety issues of metallized film capacitors are becoming more and more prominent. Metallized film capacitors are generally formed by winding two half-grid metallized films in pairs to improve safety.
[0003] In the related art, metallized safety films of various mesh shapes and sizes are disclosed, but usually they cannot take into account the performance or requirements of all aspects of the capacitor, including: First, the isolation mesh unit is a partition structure, and the metal plating is not connected by a fuse. When an electrical weak point breakdown occurs in the metallized film, the electrical weak point position is only isolated by the self-healing property of the film itself, which easily forms a penetrating multi-layer breakdown, resulting in an insufficient safety factor of the capacitor; Second, in pursuit of higher metallized film area utilization, higher operating voltage, and higher operating temperature, the area size of the mesh unit, the order arrangement, the mesh blanking structure and other structures, resulting in unnecessary mesh units caused by self-healing. Reduced area that can be connected, accelerated capacitance loss, and reduced service life, and other problems need to be further resolved. Utility Model Content
[0004] The utility model aims to solve at least one of the technical problems in the above-mentioned technology to a certain extent. To this end, the purpose of the utility model is to provide a thin film capacitor so that the grid unit where the metallized film electrical weak point is located can provide appropriate self-healing energy, thereby reducing the reduction in capacitance area caused by the completion of self-healing of the metallized film.
[0005] To achieve the above-mentioned purpose, an embodiment of the utility model proposes a thin film capacitor, including a metallized film, wherein the metallized film is composed of a dielectric film and a metal coating arranged on the dielectric film; the metal coating includes at least two orders of continuously repeated grid units extending in the longitudinal direction, the grid units are separated by insulating gaps, and the grid units are connected by fuses, and the lateral width of the grid units of the first order connected to the retained edge is smaller than the lateral width of the grid units of other orders.
[0006] According to a thin film capacitor of an embodiment of the utility model, since the metal plating layer includes at least two orders of continuously repeated grid units extending in the longitudinal direction, the lateral width of the first-order grid units connected to the retained edge is smaller than the lateral width of the other order grid units, so that when two metallized films are stacked, the small-width first-order grid units of one of the metallized films correspond to the thickened square resistance and transition square resistance areas of the other metallized film, thereby reducing the reduction in effective capacitance area caused by self-healing in the low square resistance area.
[0007] In addition, a film capacitor according to the above embodiment of the utility model may also have the following additional technical features:
[0008] Optionally, the horizontal width of the grid unit is 3.5mm-18mm, the vertical straight length of the grid unit is 1mm-8mm, and the area of the grid unit is 8mm 2 -70mm 2 The metal coating includes at least two steps of continuous and repeated grid units extending in the longitudinal direction, the grid units have a lateral width of 3.5 mm to 18 mm, a longitudinal straight length of 1 mm to 8 mm, and an area of 8 mm. 2 -70mm 2 The order of the grid cells is differentiated according to the longitudinal straight line length of the metallized film, so that the reduction in effective capacitance area caused by self-healing of the grid cells in a certain order is as small as possible.
[0009] Optionally, the metallized film comprises two sheets stacked at staggered edges, wherein the first-order grid units with small width of one metallized film correspond to the thickened square resistance and transition square resistance regions of the other metallized film.
[0010] Specifically, the lateral width of the overlapping portion of the two metallized film grid unit regions is greater than or equal to 2 mm, thereby avoiding excessive heat accumulation caused by the two metallized films in the middle area of the capacitor core when the capacitor core is subjected to high current re-flash, reducing the probability of thermal failure, and thereby improving the safety of the capacitor.
[0011] Specifically, the two metallized films have the same structure, and the two metallized films are stacked in a mirror-symmetrical manner.
[0012] Optionally, the metal coating also includes a fully metallized conductive layer extending longitudinally, and the grid unit includes a longitudinal insulating gap, a transverse insulating gap, and a metal coating grid located within the longitudinal insulating gap and the transverse insulating gap, and fuses are provided on the longitudinal insulating gap and the transverse insulating gap to connect the metal coating grid with the fully metallized conductive layer.
[0013] Specifically, the longitudinal insulation gap or the transverse insulation gap is arranged to be in a wave shape, and the height difference between the crest and the trough of the wave is 0.3 mm-10 mm. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a schematic diagram of the expansion of two metallized films in an embodiment of the utility model;
[0015] Figure 2 A schematic diagram of the metallized coating structure of an embodiment of the utility model;
[0016] Figure 3 Another schematic diagram of the structure of the metallized coating according to an embodiment of the present invention.
[0017] Description of symbols
[0018] Metallized film 1, dielectric film 11, metal plating 12, grid unit 121, longitudinal insulating gap 1211, transverse insulating gap 1212, metal plating grid 1213, fuse 122, fully metallized conductive layer 123, margin 13. DETAILED DESCRIPTION
[0019] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.
[0020] In order to better understand the above technical solution, 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 accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, 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.
[0021] like Figures 1 to 3 As shown, a film capacitor disclosed in an embodiment of the utility model comprises a metallized film 1, wherein the metallized film 1 comprises a dielectric film 11 and a metal coating 12 disposed on the dielectric film 11. The film width direction of the metallized film 1 is defined as the transverse direction, and the direction orthogonal thereto is defined as the longitudinal direction.
[0022] The metal plating layer 12 includes at least two steps of continuous and repeated grid units 121 extending in the longitudinal direction, the grid units 121 are separated by insulating gaps, and the grid units 121 are connected by fuses 122, the horizontal width L1 of the grid unit 121 is 3.5mm-18mm, the horizontal width of the grid unit 121 of the first step connected to the margin 13 is smaller than the horizontal width of the grid unit 121 of the other steps, the longitudinal straight line length L2 of the grid unit 121 is 1mm-8mm, and the area of the grid unit 121 is 8mm 2 -70mm 2 .
[0023] In this embodiment, the continuously repeated grid units 121 extending in the longitudinal direction are arranged in three stages, and the first-stage, second-stage, and third-stage grid units 121 are arranged from the center of the metallized film 1 to the edge margin 13, respectively. The lateral width of the third-stage grid unit 121 connected to the margin 13 is smaller than the lateral width of the first-stage and second-stage grid units 121.
[0024] Since the metal coating 12 includes at least two orders of continuously repeated grid units 121 extending in the longitudinal direction, the lateral width of the first-order grid units 121 connected to the margin 13 is smaller than the lateral width of the other order grid units 121, so that when two metallized films 1 are stacked, the small-width first-order grid units 121 of one of the metallized films 1 correspond to the thickened square resistance and transition square resistance areas of the other metallized film 1, thereby reducing the reduction in effective capacitance area caused by self-healing in the low square resistance area.
[0025] At the same time, since the metal coating 12 includes at least two steps of continuous and repeated grid units 121 extending in the longitudinal direction, the grid unit 121 has a lateral width of 3.5 mm to 18 mm, a longitudinal straight length of 1 mm to 8 mm, and an area of 8 mm 2 -70mm 2 The order of the grid unit 121 is differentiated according to the longitudinal straight line length of the metallized film 1, so that the reduction in effective capacitance area caused by self-healing of the grid unit 121 in a certain order is as small as possible.
[0026] Optionally, the metallized film 1 comprises two sheets stacked at different sides, wherein the first-order grid unit 121 with a small width of one metallized film 1 corresponds to the thickened square resistance and transition square resistance area of the other metallized film 1, thereby reducing the reduction in effective capacitance area caused by self-healing in the low square resistance area. Specifically, Figure 2 As shown, the two metallized films 1 have the same structure, and the two metallized films 1 are stacked in a mirror-symmetrical manner; Figure 3 As shown, the structures of the two metallized films 1 may also be different. The structures of the third-order grid units 121 of the two metallized films 1 are different, and the small-width first-order grid unit 121 of one metallized film 1 corresponds to the thickened square resistance and transition square resistance area of the other metallized film 1.
[0027] Specifically, the lateral width b of the overlapping portion of the grid unit 121 area of the two metallized films 1 is greater than or equal to 2 mm, thereby avoiding excessive heat accumulation caused by the two metallized films 1 in the middle area of the capacitor core when the capacitor core is subjected to a large current re-flash, reducing the probability of thermal failure, and thereby improving the safety of the capacitor.
[0028] Optionally, the metal plating layer 12 further includes a fully metallized conductive layer 123 extending in the longitudinal direction, the grid unit 121 includes a longitudinal insulating gap 1211, a transverse insulating gap 1212, and a metal plating grid 1213 located in the longitudinal insulating gap 1211 and the transverse insulating gap 1212, and a fuse 122 is provided on the longitudinal insulating gap 1211 and the transverse insulating gap 1212 to connect the metal plating grid 12 with the fully metallized conductive layer 123. Specifically, the longitudinal insulating gap 1211 or the transverse insulating gap 1212 is configured to be wavy, and the height difference d between the crest and the trough of the wave is 0.3 mm-10 mm.
[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.
[0030] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0031] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0032] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.
[0033] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms should not be understood as necessarily being directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.
[0034] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.
Claims
1. A film capacitor, characterized in that: It comprises a metallized film, which is composed of a dielectric film and a metal coating arranged on the dielectric film; the metal coating comprises at least two levels of continuously repeated grid units extending in the longitudinal direction, the grid units are separated by insulating gaps, and the grid units are connected by fuses, and the lateral width of the grid units of the first level connected to the margin is smaller than the lateral width of the grid units of other levels.
2. A film capacitor according to claim 1, characterized in that: The horizontal width of the grid unit is 3.5mm-18mm, the vertical straight length of the grid unit is 1mm-8mm, and the area of the grid unit is 8mm 2 -70mm 2 .
3. A film capacitor according to claim 1, characterized in that: The metallized film comprises two sheets stacked at staggered edges, wherein the first-order grid units with small width of one metallized film correspond to the thickened square resistance and transition square resistance regions of the other metallized film.
4. A film capacitor as claimed in claim 3, characterized in that: The lateral width of the overlapping portion of the two metallized film grid unit regions is greater than or equal to 2 mm.
5. A film capacitor according to claim 3, characterized in that: The two metallized films have the same structure, and are stacked in a mirror-symmetrical manner.
6. A film capacitor according to claim 1, characterized in that: The metal coating also includes a fully metallized conductive layer extending in the longitudinal direction. The grid unit includes a longitudinal insulating gap, a transverse insulating gap, and a metal coating grid located in the longitudinal insulating gap and the transverse insulating gap. Fuses are provided on the longitudinal insulating gap and the transverse insulating gap to connect the metal coating grid with the fully metallized conductive layer.
7. A film capacitor according to claim 6, characterized in that: The longitudinal insulation gap or the transverse insulation gap is arranged in a wave shape, and the height difference between the crest and the trough of the wave is 0.3 mm-10 mm.