Thin film capacitor with high capacity
By designing protrusions or grooves on the aluminum foil of the film capacitor and combining them with the design of dielectric and conductive film layers, the capacitance of the film capacitor is increased, solving the problem of insufficient capacitance of existing film capacitors and improving the frequency characteristics and dielectric loss performance of signal transmission.
Patent Information
- Application Number
- CN202520104781.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-16
- Publication Date
- 2026-02-17
- Estimated Expiration
- 2035-01-16
AI Technical Summary
Existing film capacitors have relatively small capacitance, making it difficult to meet the needs of certain high-frequency signal transmissions.
Raises or grooves are formed on the first electrode aluminum foil of the film capacitor to increase the surface area, and raised or grooved surfaces are formed on the softened dielectric film layer. Conductive polymer is filled to form a conductive film layer. Raises or grooves can be optionally provided on the surface of the second electrode aluminum foil.
By increasing the electrode surface area, the capacitance of thin-film capacitors can be increased by 5%-20%, ensuring that the frequency characteristics of signal transmission and dielectric loss are reduced.
Smart Images
Figure CN223927214U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a capacitor especially to a thin film capacitor with high capacity. BACKGROUND
[0002] The thin film capacitor has the following characteristics: no polarity, high insulation impedance, excellent frequency characteristics (wide frequency response), and small dielectric loss. Based on the above advantages, the thin film capacitor is widely used in analog circuits. Especially in the signal connection part, a capacitor with good frequency characteristics and extremely low dielectric loss must be used to ensure that the signal transmission does not have too much distortion.
[0003] The conventional thin film capacitor is prepared by overlapping and winding a metal foil such as aluminum as an electrode and a plastic film. Since the surface area of the metal foil is small, the capacity of the thin film capacitor is generally small, and the capacity of the thin film capacitor is usually in the pF level. SUMMARY
[0004] The technical problem to be solved by the utility model is to overcome the shortcomings of the prior art and provide a thin film capacitor with high capacity. The capacity of the thin film capacitor can be increased by 5%-20% compared with the conventional thin film capacitor.
[0005] To solve the above technical problems, the utility model provides a technical scheme: a thin film capacitor with high capacity, comprising a first electrode, a dielectric film layer, and a second electrode, the first electrode comprises a first aluminum foil, the surface of the first aluminum foil is formed with protrusions or grooves; the dielectric film layer is attached to the first aluminum foil; the second electrode comprises a conductive film layer and a second aluminum foil, the conductive film layer is arranged between the second aluminum foil and the dielectric film layer.
[0006] The thin film capacitor with high capacity described above is preferably formed by attaching the dielectric film layer to the first aluminum foil after softening the resin film.
[0007] The thin film capacitor with high capacity described above is preferably formed by filling the protrusions or grooves formed on the surface of the dielectric film layer with a conductive polymer after the dielectric film layer is attached to the first aluminum foil; the conductive polymer is solidified to form the conductive film layer.
[0008] The thin film capacitor with high capacity described above is preferably formed by filling the protrusions or grooves formed on the surface of the dielectric film layer with a conductive polymer after the dielectric film layer is attached to the first aluminum foil; the conductive polymer is solidified to form the conductive film layer.
[0009] The thin film capacitor with high capacity described above is preferably formed by filling the protrusions or grooves formed on the surface of the dielectric film layer with a conductive polymer after the dielectric film layer is attached to the first aluminum foil; the conductive polymer is solidified to form the conductive film layer.
[0010] The capacity high thin film capacitor has preferably the protrusions or the grooves in strip shape or point shape.
[0011] The capacity high thin film capacitor has preferably the protrusions or the grooves in strip shape or point shape.
[0012] Compared with the prior art, the capacity high thin film capacitor has the advantages that the protrusions or the grooves are formed on the first aluminum foil of the first electrode to increase the surface area of the first electrode, thereby increasing the capacity of the thin film capacitor. BRIEF DESCRIPTION OF DRAWINGS
[0013] Figure 1 The capacity high thin film capacitor has preferably the protrusions or the grooves in strip shape or point shape.
[0014] Figure 2 The capacity high thin film capacitor has preferably the protrusions or the grooves in strip shape or point shape.
[0015] Figure 3 The capacity high thin film capacitor has preferably the protrusions or the grooves in strip shape or point shape.
[0016] BRIEF DESCRIPTION OF DRAWINGS
[0017] 1, core package; 2, first aluminum foil; 21, protrusion; 22, groove; 3, second electrode; 31, second aluminum foil; 32, conductive thin film layer; 4, dielectric thin film layer. DETAILED DESCRIPTION
[0018] In order to facilitate the understanding of the present application, the following will be combined with the description of the drawings and the preferred embodiments to make a more comprehensive and detailed description of the present application, but the protection scope of the present application is not limited to the following specific embodiments.
[0019] It should be particularly noted that when an element is described as being "fixed to, connected to, or communicated with" another element, it can be directly fixed, connected or communicated with the other element, or indirectly fixed, connected or communicated with the other element through other intermediate connecting elements.
[0020] Unless otherwise defined, all the professional terms used in the following are the same as those commonly understood by the skilled in the art. The professional terms used in the present application are only for the purpose of describing the specific embodiments and are not intended to limit the protection scope of the present application. Embodiment 1
[0021] As Figure 1The diagram illustrates a high-capacity film capacitor comprising a wound core 1. The core 1 includes a first electrode, a dielectric film layer 4, and a second electrode 3. During winding, the first aluminum foil 2 of the first electrode and the second aluminum foil 31 of the second electrode 3 are misaligned, extending from both ends of the core 1. The first electrode includes the first aluminum foil 2, the surface of which has protrusions 21 and / or grooves 22. The dielectric film layer 4 is attached to the first aluminum foil 2. The second electrode 3 includes a conductive film layer 32 and a second aluminum foil 31, the conductive film layer 32 being disposed between the second aluminum foil 31 and the dielectric film layer 4. The width of the dielectric film is greater than the width of the conductive film layer 32, and the conductive film layer 32 is entirely coated on the dielectric film layer 4. The dielectric film layer 4 is formed by softening a resin film and then attaching it to the first aluminum foil 2.
[0022] In this embodiment, the dielectric film used can be a plastic film such as polyethylene, polypropylene, polystyrene, or polycarbonate. Different dielectric films have different softening temperatures. For example, polyethylene film begins to soften at 125-135℃, polypropylene film at around 150℃, polystyrene film at 80℃, and polycarbonate film at around 147℃. Different softening temperatures are selected based on the softening characteristics of different dielectric films. When selecting the softening temperature, the temperature should not be too high; generally, after the resin film begins to soften, the temperature increase should not exceed 20℃, allowing the resin film to soften and adhere to the first aluminum foil 2. The time from reaching the temperature at which the resin film begins to soften to the start of cooling should not exceed 30 seconds; at this time, the resin film has not yet deformed but can still adhere to the first aluminum foil 2.
[0023] In this embodiment, as Figure 2 As shown, after the dielectric film layer 4 is attached to the first aluminum foil 2, the resin film softens but has not yet deformed. At this time, protrusions 21 and / or grooves 22 are formed on the surface of the dielectric film along with the first aluminum foil 2. The protrusions 21 or grooves 22 formed on the surface of the dielectric film layer 4 are filled with a conductive polymer. After the conductive polymer is cured, a conductive film layer 32 is formed. In this embodiment, the dielectric is a dielectric film layer, and the second aluminum foil of the second electrode actually serves as a capacitor lead-out.
[0024] In this embodiment, the thickness of the first aluminum foil 2 is between 5-20 μm, and the depth of the protrusions 21 or grooves 22 on the first aluminum foil 2 does not exceed two-thirds of the thickness of the first aluminum foil 2. During processing, the protrusions 21 and / or grooves 22 can be formed on the first aluminum foil 2 by roll forming. Figure 2As shown in the drawings, one surface of the first aluminum foil 2 is provided with protrusions 21, and the other surface is provided with recesses 22 corresponding to the protrusions 21; in this embodiment, the protrusions 21 or the recesses 22 are in the form of an array of dots, the protrusions 21 are semispherical protrusions, and the corresponding recesses 22 are semispherical recesses; the diameter of the bottom of the semispherical protrusions and the semispherical recesses is between 1-5mm.
[0025] In other embodiments, the protrusions 21 or the recesses 22 can be in the form of strips, and the protrusion strips or the recess strips on the first aluminum foil 2 are parallel. The distance between two adjacent protrusion strips is greater than or equal to the width of the bottom of the protrusion strip.
[0026] In this embodiment, the surface of the second aluminum foil 31 can be provided with protrusions 21 or / and recesses 22; or can be a smooth foil without protrusions 21 or / and recesses 22; the thickness of the second aluminum foil 31 is the same as the thickness of the first aluminum foil 2.
[0027] In other embodiments, the surface of the first aluminum foil 2 can be provided with protrusions 21 or / and recesses 22 as shown in the drawings. Figure 3 As shown in the drawings, the upper surface of the first aluminum foil 2 is provided with recesses, and the lower surface is smooth.
[0028] In the utility model, the protrusions 21 or / and recesses 22 are formed on the first aluminum foil 2 of the first electrode, so as to increase the surface area of the first electrode, thereby increasing the capacity of the film capacitor. In the utility model, the resin film is softened and attached to the first aluminum foil 2 to form a dielectric film layer 4, so that the dielectric film layer 4 is tightly attached to the first aluminum foil 2, thereby ensuring the capacity of the film capacitor.
[0029] Comparative Example 1
[0030] In Comparative Example 1, the first electrode and the second electrode 3 are both provided with the first aluminum foil 2 and the second aluminum foil 31 in the form of a smooth foil; the size of the electrode and the dielectric film is the same as that in Example 1; and the other structures are the same as those in Example 1. Ten film capacitors in Example 1 and Comparative Example 1 are selected respectively, and the average capacity of the film capacitors in Example 1 and Comparative Example 1 is 102.7pF and 86.6pF respectively.
Claims
1. A thin film capacitor having a high capacitance, characterized by: The electrode includes a first electrode, a dielectric film layer and a second electrode, the first electrode includes a first aluminum foil, the surface of the first aluminum foil is formed with protrusions or / and grooves; the dielectric film layer is attached to the first aluminum foil; the second electrode includes a conductive film layer and a second aluminum foil, the conductive film layer is arranged between the second aluminum foil and the dielectric film layer.
2. The thin film capacitor having a large capacity according to claim 1, wherein: The dielectric film layer is formed by attaching a softened resin film to the first aluminum foil.
3. The thin film capacitor having a large capacity according to claim 1, wherein: After the dielectric film layer is attached to the first aluminum foil, the protrusions or / and grooves formed on the surface of the dielectric film layer are filled with a conductive polymer; the conductive polymer is solidified to form the conductive film layer.
4. The thin film capacitor of any one of claims 1 to 3, wherein: The thickness of the first aluminum foil is between 5-20μm, and the depth of the protrusions or / and grooves on the first aluminum foil is not more than two-thirds of the thickness of the first aluminum foil.
5. The thin film capacitor of any one of claims 1-3, wherein: One surface of the first aluminum foil is protruded, and the other surface is formed with grooves corresponding to the protrusions.
6. The thin film capacitor of any one of claims 1 to 3, wherein: The protrusions or / and grooves are in the form of strips or dots.
7. The thin film capacitor of any one of claims 1-3, wherein: The surface of the second aluminum foil is formed with protrusions or / and grooves.