Semi-Y-shaped safety film
By designing the arc-shaped corners and double-layer thickening of the semi-Y-shaped safety film, the problems of electric field concentration and uneven current density in the corner area of the capacitor film are solved, thereby improving the surge resistance and service life of the capacitor.
Patent Information
- Application Number
- CN202511447360.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-11
- Publication Date
- 2026-01-06
AI Technical Summary
Existing capacitor films are prone to local electric field concentration due to current line congestion at corners, which can lead to local breakdown. In addition, the uneven thickness of the metallized film causes differences in current density, affecting the capacitor's surge resistance and service life.
The safety membrane adopts a semi-Y-shaped design, including a base film, a thickened layer, an active layer, and a blank layer. The isolation strip is semi-Y-shaped, with rounded corners and double-layer thickened layers. The length of the hexagonal pattern gradually increases, and the width and spacing of the isolation strip are limited. The fuse is located in the rounded area.
To prevent breakdown due to excessively high electric field at electrode corners, uniformly distribute stress, avoid overheating and melting due to current, use double-layer thickened layers to share current, avoid single-layer breakdown, and improve the capacitor's surge resistance and service life.
Smart Images

Figure CN121282006A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of film technology for manufacturing capacitors, and particularly relates to a semi-Y-shaped safety film. Background Technology
[0002] Film capacitors are a type of capacitor made using organic or inorganic thin films as the dielectric and metal foils or metallized layers as electrodes, manufactured through processes such as winding and lamination. They possess advantages such as good high-frequency characteristics, high insulation resistance, long lifespan, and good temperature stability, making them indispensable in fields such as electronics, new energy, and industrial control. Consequently, some capacitors have appeared on the market, such as those with announcement numbers CN118231142A and CN117912844A. However, these capacitors suffer from several drawbacks. In the corner areas of the insulating zone within the capacitor film, "current line congestion" can create localized electric field concentration, leading to localized breakdown and affecting the capacitor's surge resistance and rated voltage withstand value. Furthermore, the metallized film in these capacitors has a single thickened layer, requiring high uniformity in film thickness. Uneven thickness can cause differences in current density, leading to localized overheating and impacting the capacitor's lifespan. Summary of the Invention
[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a semi-Y-shaped safety film that can overcome or at least partially solve the above problems.
[0004] To achieve the above objectives, the present invention adopts the following technical solution: A semi-Y-shaped safety film includes a base film and a coating layer disposed on the base film. The coating layer has a thickened layer, a movable layer, and a blank layer. The thickened layer and the blank layer are located on both sides of the movable layer. A semi-Y-shaped isolation strip is provided inside the movable layer. The width of the semi-Y-shaped isolation strip is b. The semi-Y-shaped isolation strip divides the movable layer into multiple neatly arranged hexagonal patterns. A fuse is provided on the semi-Y-shaped isolation strip. The connection area of the semi-Y-shaped isolation strip is an arc-shaped structure with a radius of R. R and b have the following constraint relationship: R = (3~5) * b; The area where the fuse is installed in the semi-Y-shaped isolation strip is an arc-shaped structure with a radius of r. The following constraint relationship exists between r and b: r = (0.4~0.5) * b.
[0005] Furthermore, the semi-Y-shaped isolation strip divides the active layer into 3-4 rows of hexagonal patterns, with each row of hexagonal patterns having the same length.
[0006] Preferably, the lengths of the hexagonal pattern from top to bottom are K, L, and M, and K:L:M = 3:4:7; When the hexagonal pattern has 4 rows, the lengths of the hexagonal pattern from top to bottom are K, L, M, N, and K:L:M:N = 3:3:5:6.
[0007] Furthermore, the thickened layer includes a first thickened layer and a second thickened layer, wherein the first thickened layer and the second thickened layer are in the form of edge-thickened slope square resistance, and the material is aluminum-zinc alloy.
[0008] Furthermore, the first thickened layer includes a first thickened portion and a first slope portion, wherein the sheet resistance of the first thickened portion is 2~4Ω / □ and the sheet resistance of the first slope portion is 5~7Ω / □.
[0009] Furthermore, the second thickened layer includes a second thickened portion and a second sloped portion, and the sheet resistance of the second thickened portion and the second sloped portion is 8~11Ω / □.
[0010] Furthermore, the active layer is made of aluminum and has a sheet resistance of 25±4Ω / □.
[0011] Preferably, the vertical distance from the top of the oblique branch to the corner of the semi-Y-shaped isolation strip is h, and the distance between two adjacent semi-Y-shaped isolation strips is d. The following constraint relationship exists between h and d: h = (0.3~0.5) * d.
[0012] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art: 1. The present invention, by setting the corner area of the isolation strip in an arc shape, can prevent the capacitor electrodes from accumulating at the tip of the corner area, causing the electric field strength in the corner area to be too high, thereby causing local breakdown. In addition, during production or use, under high temperature or bending conditions, stress concentration is easily formed in the corner area. The arc shape design can make the stress evenly distributed along the arc surface, avoiding stress concentration that causes the isolation strip to crack and leads to capacitor failure.
[0013] 2. By designing the hexagonal pattern with its length gradually increasing from top to bottom, the resistance of the hexagonal pattern can be increased sequentially from top to bottom. This causes the heat generated when the same current passes through the active area to increase sequentially, preventing excessive heat generated by the current at the front of the active area from gradually accumulating and causing multiple areas to melt simultaneously or localized overburning.
[0014] 3. By designing the first and second thickened layers, the capacitor can be prevented from completely failing when the single thickened layer partially melts or breaks down. The design of the double thickened layers is equivalent to adding a parallel channel. When there is a local thin area in one layer, the other layer can share part of the current, avoiding the capacitor being broken down due to excessive current density in a single channel. The addition of a thickened slope zone can prevent the coating thickness from changing abruptly in a step-like manner, which would cause the electric field strength to increase sharply at the step, triggering edge discharge and leading to local breakdown and failure of the capacitor.
[0015] 4. By restricting the constraint relationship between h and d, the angle of the isolation strip in the corner area can be controlled. The smaller the angle, the more obvious the electric field lines accumulate in the corner area, the greater the local electric field intensity, and the greater the risk of breakdown. The larger the angle, the more dispersed the current path will be, making it impossible to accurately guide the target area. Moreover, a large angle will increase the width of the invention and limit the miniaturization of the component.
[0016] In summary, the present invention, through the design of the arc-shaped corner of the isolation zone and the constraint relationship between h and d, can avoid local breakdown caused by the accumulation of electric field lines; through the design of the hexagonal pattern with the length gradually increasing from top to bottom, heat can be gradually accumulated, avoiding simultaneous melting of multiple areas or excessive local burning; through the setting of double thickened layers, the current flow can be dispersed, avoiding the capacitor breakdown caused by excessive current density in a single thickened layer. Attached Figure Description
[0017] Figure 1 This is a horizontal cross-sectional view of a semi-Y-shaped safety film proposed in this invention, when the hexagonal pattern consists of three rows; Figure 2 This is a vertical cross-sectional view of a semi-Y-shaped safety film proposed in this invention, when the hexagonal pattern consists of three rows. Figure 3 This is a horizontal cross-sectional view of a semi-Y-shaped safety film proposed in this invention, when the hexagonal pattern consists of four rows. Figure 4 This is a schematic diagram of a vertical cross-section of a semi-Y-shaped safety film proposed in this invention, when the hexagonal pattern consists of four rows. Figure 5 For the present invention Figure 4 An enlarged schematic diagram of the local structure at point A in the middle.
[0018] In the diagram: 1. Base film; 2. Thickened layer; 3. Active layer; 4. Blank layer; 5. Semi-Y-shaped isolation strip; 6. Fuse; 7. First thickened section; 8. First slope section; 9. Second thickened section; 10. Second slope section. Detailed Implementation
[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.
[0020] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0021] Example 1: Reference Figures 1-5 A semi-Y-shaped safety film includes a base film 1 and a coating layer disposed on the base film 1. The coating layer includes a thickening layer 2, an active layer 3, and a blank layer 4. The thickening layer 2 and the blank layer 4 are respectively located on both sides of the active layer 3. A semi-Y-shaped isolation strip 5 is provided inside the active layer 3. The width of the semi-Y-shaped isolation strip 5 is b. The semi-Y-shaped isolation strip 5 divides the active layer 3 into multiple neatly arranged hexagonal patterns. A fuse 6 is provided on the semi-Y-shaped isolation strip 5. The connection area of the semi-Y-shaped isolation strip 5 is an arc-shaped structure with a radius of R. R and b have the following constraint relationship: R = (3~5) * b; The area where the fuse 6 is installed in the semi-Y-shaped isolation strip 5 is an arc-shaped structure with a radius of r. The following constraint relationship exists between r and b: r = (0.4~0.5) * b; This invention, through the arc-shaped design of the insulating strip corner area, can prevent the capacitor electrodes from accumulating at the tip of the corner area, thus preventing excessively high electric field strength at the corner area and causing local breakdown. Furthermore, during production or use, stress concentration can easily form at the corner area under high temperature or bending conditions. The arc-shaped design can distribute the stress evenly along the arc surface, avoiding stress concentration that could cause the insulating strip to crack and lead to capacitor failure.
[0022] Example 2: Reference Figure 2 and Figure 4 Based on Example 1, the difference is that the semi-Y-shaped isolation strip 5 divides the active layer 3 into 3 to 4 rows of hexagonal patterns, with each row of hexagonal patterns having the same length; When there are 3 rows of hexagonal patterns, the lengths of the hexagonal patterns from top to bottom are K, L, and M, and K:L:M = 3:4:7; When the hexagonal pattern has 4 rows, the lengths of the hexagonal pattern from top to bottom are K, L, M, N, and K:L:M:N = 3:3:5:6; By designing the hexagonal pattern with its length gradually increasing from top to bottom, the resistance of the hexagonal pattern can be increased sequentially from top to bottom. This causes the heat generated when the same current passes through the active area to increase sequentially, preventing excessive heat generated by the current at the front of the active area from gradually accumulating and causing multiple areas to melt simultaneously or localized overburning.
[0023] Example 3: Reference Figures 1-4 Based on Example 1, the difference is that the thickened layer 2 includes a first thickened layer and a second thickened layer, the first thickened layer and the second thickened layer are in the form of edge thickened slope square resistance, and the material is aluminum-zinc alloy; The first thickened layer includes a first thickened portion 7 and a first slope portion 8. The sheet resistance of the first thickened portion 7 is 2~4Ω / □, and the sheet resistance of the first slope portion 8 is 5~7Ω / □. The second thickened layer includes a second thickened portion 9 and a second slope portion 10, and the sheet resistance of the second thickened portion 9 and the second slope portion 10 is 8~11Ω / □; The active layer 3 is made of aluminum, and its sheet resistance is 25±4Ω / □. By designing the first and second thickening layers, the capacitor can be prevented from completely failing when the single thickening layer partially melts or breaks down. The double thickening layer design is equivalent to adding a parallel channel. When there is a local thin area in one layer, the other layer can share part of the current, avoiding the capacitor being broken down due to excessive current density in a single channel. The addition of a thickened slope zone can prevent the coating thickness from changing abruptly in a step-like manner, which would cause the electric field strength to increase sharply at the step, triggering edge discharge and leading to local breakdown and failure of the capacitor.
[0024] Example 4: Reference Figure 5 Based on Example 1, the difference is that the vertical distance from the top of the oblique branch to the corner of the semi-Y-shaped isolation strip 5 is h, and the distance between two adjacent semi-Y-shaped isolation strips 5 is d. The following constraint relationship exists between h and d: h = (0.3~0.5) * d; By restricting the constraint relationship between h and d, the angle of the isolation strip at the corner can be controlled. The smaller the angle, the more obvious the electric field lines accumulate at the corner, the greater the local electric field strength, and the greater the risk of breakdown. The larger the angle, the more dispersed the current path will be, making it impossible to accurately guide the current to the target area. Furthermore, a large angle will increase the width of the invention and limit the miniaturization of the components.
[0025] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A semi-Y-shaped safety film, comprising a base film (1) and a plating layer provided on the base film (1), the plating layer having a thickened layer (2), an active layer (3) and a blank layer (4), the thickened layer (2) and the blank layer (4) being respectively located on both sides of the active layer (3), characterized in that: the active layer (3) is internally provided with a semi-Y-shaped isolation belt (5), the width of the semi-Y-shaped isolation belt (5) being b, and the semi-Y-shaped isolation belt (5) divides the active layer (3) into a plurality of regularly arranged hexagonal patterns, the semi-Y-shaped isolation belt (5) is provided with a fuse (6), the connection area of the semi-Y-shaped isolation belt (5) is in a circular arc structure, the radius of the circular arc being R, and R and b satisfy the following constraint relationship: R = (3-5)*b, the area of the semi-Y-shaped isolation belt (5) provided with the fuse (6) is in a circular arc structure, the radius of the circular arc being r, and r and b satisfy the following constraint relationship: r = (0.4-0.5)*b, the semi-Y-shaped isolation belt (5) divides the active layer (3) into 3-4 rows of hexagonal patterns, and the length of each row of hexagonal patterns is the same, when the hexagonal patterns are 3 rows, the lengths of the hexagonal patterns from top to bottom are K, L and M in turn, and K:L:M = 3:4:7, when the hexagonal patterns are 4 rows, the lengths of the hexagonal patterns from top to bottom are K, L, M and N in turn, and K:L:M:N = 3:3:5:6, the thickened layer (2) comprises a first thickened layer and a second thickened layer, the first thickened layer and the second thickened layer are in the form of edge thickened slope square resistance, and the material is aluminum-zinc alloy, the first thickened layer comprises a first thickened part (7) and a first slope part (8), the square resistance of the first thickened part (7) is 2-4 Ω / □, and the square resistance of the first slope part (8) is 5-7 Ω / □, the second thickened layer comprises a second thickened part (9) and a second slope part (10), and the square resistance of the second thickened part (9) and the second slope part (10) is 8-11 Ω / □, the material of the active layer (3) is aluminum, and the square resistance is 25±4 Ω / □, the vertical distance from the top end of the oblique branch of the semi-Y-shaped isolation belt (5) to the corner is h, the distance between two adjacent semi-Y-shaped isolation belts (5) is d, and h and d satisfy the following constraint relationship: h = (0.3-0.5)*d. 2. A semi-Y safety film according to claim 1, wherein 3. A semi-Y safety film according to claim 2, wherein 4. A semi-Y safety film according to claim 1, wherein 5. A semi-Y safety film according to claim 4, wherein 6. A semi-Y safety film according to claim 4, wherein 7. A semi-Y safety film according to claim 1, wherein 8. A semi-Y safety film according to claim 1, wherein
Citation Information
Patent Citations
Capacitor core and track circuit compensation capacitor
CN117912844A
Asymmetric isolation type metalized safety film
CN118231142A