Thin film capacitor
By providing a small area grid cell in a specific area in the metallized film of the film capacitor, the problem of reducing the utilization rate of the metallized film in the prior art is solved, and the effect of reducing the capacity loss rate and maintaining a high utilization rate is achieved.
Patent Information
- Application Number
- CN202421172461.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-27
- Publication Date
- 2025-04-15
- Estimated Expiration
- 2034-05-27
AI Technical Summary
When the existing thin film capacitors reduce the core capacity, the utilization rate of the metallized film is reduced, making it difficult to simultaneously reduce the core capacity loss rate and ensure the utilization rate of the metallized film.
Two metallized films are used that are stacked with mirror symmetrical images, one of which is less than 80% of the grid cell area in a specific area, so as to reduce the capacity loss rate during self-healing and maintain the high utilization rate of the metallized film.
By reducing the mesh cell area in a specific area, the capacity loss rate during self-healing is reduced, and the high utilization rate of the metallized film is ensured, thereby achieving effective performance improvement of the film capacitor.
Smart Images
Figure CN222762811U_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] With the rapid development of power electronics technology, film capacitors are increasingly used in industrial control, new energy, automotive electronics, rail transit, power grids and other fields. One of the development trends of film capacitors is miniaturization, which requires the metallized film to continuously improve its voltage resistance per unit thickness.
[0003] Film capacitors are formed by stacking two metallized films with staggered edges. Metallized films generally use a vapor deposition process to attach aluminum and zinc to the surface of the film medium to form a conductive electrode. At the same time, two semi-grid metallized films are paired to improve the safety of film capacitors and control the capacity loss rate. In related technologies, metallized films use a semi-grid design in which the area of each grid block in the film width direction is generally set to the same area, which will cause the following problems:
[0004] Since the self-healing points of the capacitor core are distributed in a certain regularity, generally distributed near the thickened coating area and the transition area, when the capacity of the core needs to be reduced, the area of a single block must be reduced, which will also reduce the utilization rate of the metallized safety film. Utility Model Content
[0005] The utility model aims to solve one of the technical problems in the above technology at least to a certain extent. To this end, one purpose of the utility model is to provide a film capacitor that can reduce the core capacity loss rate and ensure the utilization rate of the metallized film.
[0006] To achieve the above-mentioned object, the first embodiment of the utility model provides a thin film capacitor, comprising two metallized films stacked and wound with staggered edges, the two metallized films having the same structure and being stacked in mirror symmetry;
[0007] The metallized film is composed of a dielectric film and a metal coating disposed on the dielectric film, wherein the metal coating comprises at least two steps of continuously repeated grid units extending in the longitudinal direction; the metal coating comprises a first thickened area, a non-thickened area, and a transition area between the first thickened area and the non-thickened area disposed in the transverse direction, and on the metal coating, an area within 4 mm on both sides of a center line with the end position of the first thickened area as the first area, and an area within 4 mm on both sides of a center line with the end position of the transition area as the second area;
[0008] After the two metallized films are stacked, the grid unit area of the first region and the second region of one of the metallized films corresponding to the other metallized film is less than 80% of the grid unit area of other regions.
[0009] According to a thin film capacitor of an embodiment of the utility model, after two metallized films are stacked, the area of the grid unit arranged in the area within 4 mm near the end position of the first thickened area of one of the metallized films and within 4 mm near the end position of the transition area of the other metallized film corresponding to this area is smaller than 80% of the area of the grid unit in other areas. In this way, when self-healing occurs in the area where the small-area grid unit is located, the core capacity loss rate can be reduced and the utilization rate of the metallized film can be ensured.
[0010] In addition, a film capacitor according to the above embodiment of the utility model may also have the following additional technical features:
[0011] Optionally, a second thickened area is provided on the non-thickened area, and the area within 4 mm on both sides of the center line with the end position of the second thickened area as the third area. After the two metallized films are stacked, the grid unit area of the other metallized film corresponding to the third area of one of the metallized films is less than 80% of the grid unit area of other areas.
[0012] Optionally, the lateral width of the small-area grid unit of the metallized film is smaller than the lateral width of other grid units.
[0013] Optionally, the longitudinal width of the grid unit with a small area of the metallized film is smaller than the longitudinal width of other grid units.
[0014] Furthermore, the number of the second thickened area is at least one.
[0015] Optionally, the thickness of the transition zone gradually decreases from the first thickened zone to the non-thickened zone.
[0016] Optionally, the grid units are separated by insulating gaps, and the grid units are connected by fuses. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a cross-sectional view of two metallized films of the first embodiment of the utility model;
[0018] Figure 2 The cross-sectional view and the plan view of two metallized films of the first embodiment of the utility model;
[0019] Figure 3 The cross-sectional view and the plan view of two metallized films of the second embodiment of the utility model;
[0020] Figure 4 It is a cross-sectional view and a plan view of two metallized films of the second embodiment of the utility model.
[0021] Description of labels:
[0022] Metallized film 1, dielectric film 11, metal plating 12, grid unit 121, first thickened area 122, non-thickened area 123, transition area 124, longitudinal insulating gap 125, transverse insulating gap 126, second thickened area 127, and margin 13. DETAILED DESCRIPTION
[0023] 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.
[0024] 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.
[0025] like Figure 1 and Figure 2 As shown, a film capacitor of an embodiment of the utility model comprises two metallized films 1 stacked and wound staggered, the two metallized films 1 have the same structure and are stacked in mirror symmetry. 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.
[0026] Specifically, the metallized film 1 is composed of a dielectric film 11 and a metal coating 12 arranged on the dielectric film 11, and the metal coating 12 includes at least two steps of continuously repeated grid units 121 extending in the longitudinal direction; the metal coating 12 includes a first thickened area 122, a non-thickened area 123 and a transition area 124 located between the first thickened area 122 and the non-thickened area 123 arranged in the transverse direction. On the metal coating 12, the area within 4 mm on both sides of the left and right sides of the end position E1 of the first thickened area 122 is defined as the first area, and the area within 4 mm on both sides of the left and right sides of the end position E2 of the transition area 124 is defined as the second area; after the two metallized films 1 are stacked, the area of the grid unit 121a of the first area and the second area of one metallized film 1 corresponding to the other metallized film 1 is less than 80% of the area of the grid unit 121b in other areas.
[0027] Understandably, if Figure 1 and 2 As shown, the two metallized films 1 have the same structure, are mirror-symmetrically stacked, and the small-area grid unit of one metallized film 1 corresponds to the thickened square resistance area (first area, second area) of the other metallized film 1 .
[0028] Therefore, according to a thin film capacitor of an embodiment of the utility model, after two metallized films 1 are stacked, the area of the grid unit 121a set in the area within 4 mm near the end position E1 of the first thickened area 122 of one of the metallized films 1 and within 4 mm near the end position E2 of the transition zone 124 of the other metallized film 1 is smaller than 80% of the area of the grid unit 121b in other areas. In this way, when self-healing occurs in the area where the small-area grid unit 121a is located, the core capacity loss rate can be reduced and the utilization rate of the metallized film 1 can be ensured.
[0029] The above implementation is the most basic solution of this application, which can solve the problems raised in the background technology and achieve the purpose of this application. The following improves the above basic solution in many aspects to further improve its performance, thereby achieving better implementation effect.
[0030] Example 1
[0031] like Figure 1 and Figure 2 As shown, the film capacitor of this embodiment includes a capacitor element, which is formed by staggered winding of a first metallized film m1 and a second metallized film m2, and the "staggered sides" of the two metallized films 1 are the staggered distance. The two metallized films 1 have the same structure and are stacked in a mirror-symmetrical manner.
[0032] The metallized film 1 is composed of a dielectric film 11 and a metal coating 12 disposed on the dielectric film 11, wherein the metal coating 12 includes a first thickened area 122, a non-thickened area 123, a transition area 124, a longitudinal insulating gap 125, a transverse insulating gap 126 and a margin 13. It can be understood that, as Figure 1 As shown, the thickness of the transition zone 124 gradually decreases from the first thickened zone 122 to the non-thickened zone 123 , that is, the transition zone 124 is configured to be sloped.
[0033] The first area is defined as the area within 4 mm on both sides of the center line of the end position E1 of the first thickened area 122, and the second area is defined as the area within 4 mm on both sides of the center line of the end position E2 of the transition area 124. Figure 2The first area is defined by 2.9 mm on both sides of the center line of the end position E1 of the first thickened area 122, and the second area is defined by 1.9 mm on both sides of the center line of the end position E2 of the transition area 124.
[0034] At the same time, along the lateral direction, the metal plating layer 12 is separated by a longitudinal insulating gap 125 to form at least two rows of longitudinal grids, and the longitudinal grids include at least one row of small-area grid units 121a extending in the longitudinal direction and repeating, and at least one row of large-area grid units 121b extending in the longitudinal direction and repeating, and the grid units 121 are connected by fuses. The small-area grid units 121a are smaller than 80% of the large-area grid units 121b. For example Figure 2 , a row of small-area grid units 121a is arranged near the margin 13. After the two metallized films are stacked in an offset manner, the small-area grid units 121a of the first metallized film m1 correspond to the first area and the second area of the second metallized film m2; the small-area grid units 121a of the second metallized film m2 correspond to the first area and the second area of the first metallized film m1. Since the area of the small-area grid unit 121a is smaller than the area of the large-area grid unit 121b, when the area where the small-area grid unit 121a is located undergoes self-healing, the core capacity loss rate can be reduced and the utilization rate of the metallized film can be ensured.
[0035] More specifically, if Figure 2 As shown, the lateral width of the small-area grid unit 121a of the metallized film 1 is smaller than the lateral width of the large-area grid unit 121b. In this way, the area of the small-area grid unit 121a is smaller than the area of the large-area grid unit 121b, which can reduce the reduction in effective capacitance area caused by self-healing of the low-square resistance region.
[0036] Example 2
[0037] In this embodiment, based on the embodiment 1, a second thickened area 127 is provided on the non-thickened area 123, and the end position of the second thickened area 127 is taken as the area within 4 mm on both sides of the center lines E3 and E4 as the third area. After the two metallized films 1 are stacked, the area of the grid unit 121c of the other metallized film 1 corresponding to the third area of one of the metallized films 1 is smaller than 80% of the area of the grid unit 121b in other areas.
[0038] It can be understood that a second thickened area 127 is provided on the non-thickened area 123, so that after the two metallized films 1 are superimposed, the film surface of the metallized film 1 forms multiple support areas, reducing the stress at the support position, and improving the consistency of the air gap between the metallized films 1, so that the core capacity loss rate remains consistent. In addition, the small-area grid unit of one metallized film 1 corresponds to the thickened square resistance area (first area, second area, third area) of the other metallized film 1, so that when the area where the small-area grid units 121a and 121c are located undergoes self-healing, the core capacity loss rate can be reduced and the utilization rate of the metallized film can be guaranteed.
[0039] Alternatively, if Figure 3 As shown, the second thickened area 127 is set as one, that is, a first thickened area 122 and a second thickened area 127 are set on the metallized film 1, wherein the role of the second thickened area 127 is to reduce the stress at the support position and improve the consistency of the air gap between the metallized film 1 layers, so as to keep the core capacity loss rate consistent. The area defined by 1mm on both sides of the left and right sides of the center line with the end positions E3 and E4 of the second thickened area 127 is the third area. After the two metallized films 1 are stacked in an offset manner, the small area grid units 121a and 121c of the first metallized film m1 correspond to the first area, the second area, and the third area of the second metallized film m2; the small area grid units 121a and 121c of the second metallized film m2 correspond to the first area, the second area, and the third area of the first metallized film m1.
[0040] In addition, the second thickened area 127 can also be set to at least two, that is, at least two second thickened areas 127 are provided on the non-thickened area 123, that is, a first thickened area 122 and at least two second thickened areas 127 are provided on the metallized film 1, wherein the role of the second thickened area 127 is to reduce the stress at the supporting position and improve the consistency of the air gap between the layers of the metallized film 1, so that the core capacity loss rate remains consistent.
[0041] Example 3
[0042] The structure and principle of this embodiment are roughly the same as those of embodiment 1, except that Figure 4 As shown, the longitudinal width of the small-area grid unit 121a of the metallized film 1 is smaller than the longitudinal width of the large-area grid unit 121b. In this way, the area of the small-area grid unit 121a is smaller than the area of the large-area grid unit 121b, which can reduce the reduction in effective capacitance area caused by self-healing of the low-square resistance region.
[0043] The first area is defined as the area within 4 mm on both sides of the center line of the end position E1 of the first thickened area 122, and the second area is defined as the area within 4 mm on both sides of the center line of the end position E2 of the transition area 124. Figure 4The first area is defined by 2.9 mm on both sides of the end position E1 of the first thickened area 122 as the center line, and the second area is defined by 1.53 mm on both sides of the end position E2 of the transition area 124 as the center line.
[0044] 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.
[0045] 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.
[0046] 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.
[0047] 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.
[0048] 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.
[0049] 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 two metallized films which are stacked and wound at staggered edges, the two metallized films have the same structure and are stacked in mirror symmetry; The metallized film is composed of a dielectric film and a metal coating disposed on the dielectric film, wherein the metal coating comprises at least two steps of continuously repeated grid units extending in the longitudinal direction; the metal coating comprises a first thickened area, a non-thickened area, and a transition area between the first thickened area and the non-thickened area disposed in the transverse direction, and on the metal coating, an area within 4 mm on both sides of a center line with the end position of the first thickened area as the first area, and an area within 4 mm on both sides of a center line with the end position of the transition area as the second area; After the two metallized films are stacked, the grid unit area of the first region and the second region of one of the metallized films corresponding to the other metallized film is less than 80% of the grid unit area of other regions.
2. A film capacitor according to claim 1, characterized in that: A second thickened area is provided on the non-thickened area, and the area within 4 mm on both sides of the center line with the end position of the second thickened area as the third area. After the two metallized films are stacked, the grid unit area of the other metallized film corresponding to the third area of one of the metallized films is less than 80% of the grid unit area of other areas.
3. A film capacitor according to claim 1 or 2, characterized in that: The lateral width of the grid unit with a small area of the metallized film is smaller than the lateral width of other grid units.
4. A film capacitor according to claim 1, characterized in that: The longitudinal width of the grid unit with a small area of the metallized film is smaller than the longitudinal width of other grid units.
5. A film capacitor according to claim 2, characterized in that: The number of the second thickened area is at least one.
6. A film capacitor according to claim 1, characterized in that: The thickness of the transition zone gradually decreases from the first thickened zone to the non-thickened zone.
7. A film capacitor according to claim 1, characterized in that: The grid units are separated by insulating gaps, and the grid units are connected by fuses.