An insulated capacitor

Abstract

This utility model relates to the technical field of capacitors, specifically to an insulated capacitor. The insulated capacitor of this utility model includes a core, and an insulating layer, a fiber layer, and a metal shell layer are sequentially disposed outside the core. Adhesive filling layers are provided between the insulating layer and the fiber layer, and between the fiber layer and the metal shell layer. The fiber layer comprises a glass fiber mesh. The surface of the glass fiber mesh has a surface modification layer, the material of which includes a silane coupling agent. This utility model can improve the problem of blistering and detachment caused by reduced adhesion between the resin material and the metal shell layer during the curing process.

Description

Technical Field

[0001] This utility model relates to the technical field of capacitors, and more specifically, to an insulated capacitor. Background Technology

[0002] A capacitor is a component that stores electrical energy based on an electric field. It consists of two electrodes and a dielectric. When a capacitor is powered on, the dielectric becomes polarized, causing the positive and negative charges to separate and forming an internal electric field. Currently, the industry uses polyimide paper, PET film, PP film, barley paper, or electrical paper as the insulating medium. Then, glue is poured between the insulating medium and the metal shell layer to achieve electrical insulation between the metal shell layer and the core assembly.

[0003] However, the main components of adhesives include polyurethane resin or epoxy resin. During the curing process, the adhesion between the resin material and the metal outer shell layer decreases, easily leading to blistering and detachment. Furthermore, polyurethane or epoxy resin expands and contracts under different environments, making it prone to cracking, which further contributes to blistering. Utility Model Content

[0004] To address the problem of blistering and detachment caused by reduced adhesion between resin materials and the metal outer shell during the curing process, this invention provides an insulated capacitor. The insulated capacitor of this invention employs the following technical solution: An insulated capacitor includes a core, an insulating layer, a fiber layer and a metal shell layer are sequentially disposed outside the core, and an adhesive filling layer is provided between the insulating layer and the fiber layer, and between the fiber layer and the metal shell layer, wherein the fiber layer comprises a glass fiber mesh.

[0005] Optionally, the surface of the glass fiber mesh has a silane coupling agent modified layer.

[0006] Optionally, the glass fiber mesh is woven from a mixture of glass fiber filaments and thermally conductive fiber filaments, wherein the glass fiber filaments extend horizontally and the thermally conductive fiber filaments extend vertically.

[0007] Optionally, the mesh density of the glass fiber mesh is 16 to 100 meshes per inch.

[0008] Optionally, the fiber layer further includes a thermally conductive fiber mesh, wherein the number of glass fiber meshes is at least two, and the thermally conductive fiber mesh is disposed between at least two of the glass fiber meshes.

[0009] Optionally, the insulating capacitor further includes a buffer layer, the fiber layer comprising at least two layers of the glass fiber mesh, the buffer layer being disposed between the at least two layers of the glass fiber mesh.

[0010] Optionally, the buffer layer is mesh-like.

[0011] Optionally, the buffer layer extends in a wavy shape along the length or width of the fiber layer.

[0012] Optionally, the fiberglass mesh is detachably connected to or press-fitted to the metal outer shell layer.

[0013] Optionally, the inner wall of the metal outer shell layer is provided with a plurality of evenly distributed grooves or protrusions.

[0014] Optionally, the upper and lower ends of the fiberglass mesh extend to the two open ends of the metal outer shell layer, and the upper and lower ends of the fiberglass mesh have flanges that bend toward the metal outer shell layer, and each flange is pressed and connected to one of the open ends of the metal outer shell layer.

[0015] The advantages of this utility model compared to the prior art include: This invention adds a fiberglass mesh between the capacitor's insulation layer and metal casing layer. The fiberglass mesh possesses tensile strength and flexibility, and when attached to the inner wall of the metal casing, it forms a unified whole with the casing material. Therefore, after adhesive injection, the integrity between the metal casing and the adhesive surface is improved, increasing the adhesion between the adhesive filler layer and the metal casing. This helps ensure a tight bond between the adhesive filler layer and the metal casing, reducing voids caused by differences between the metal casing and the adhesive material. Furthermore, during the adhesive injection process to form the adhesive filler layer, the metal casing is subjected to various stresses, such as the weight of the adhesive, temperature changes, and humidity changes. The fiberglass mesh can disperse these stresses, preventing stress concentration in any one area. The fiberglass mesh also improves the flexibility of the adhesive filler layer, allowing it to better adapt to casing deformation. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the insulated capacitor in Embodiment 1 of this utility model; Figure 2 This is a schematic diagram of the structure of the glass fiber mesh fabric in Embodiment 1 of this utility model; Figure 3 This is a schematic diagram of the structure of the glass fiber mesh fabric in Embodiment 2 of this utility model; Figure 4 This is a schematic diagram of the fiber layer structure in Embodiment 3 of this utility model; Figure 5 This is a schematic diagram of the fiber layer structure in Embodiment 4 of this utility model; Figure 6This is a schematic diagram of the connection between the glass fiber mesh and the metal outer shell layer in an exemplary embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures: 1. Core; 2. Insulation layer; 3. Fiber layer; 31. Fiberglass mesh; 311. Fiberglass filament; 312. Thermally conductive fiber filament; 313. Flanged edge; 32. Thermally conductive fiber mesh; 4. Metal outer shell layer; 5. Adhesive filler layer; 6. Buffer layer. Detailed Implementation

[0018] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Although some embodiments of this utility model are shown in the drawings, it should be understood that this utility model can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this utility model. It should be understood that the drawings and embodiments of this utility model are for illustrative purposes only and are not intended to limit the scope of protection of this utility model.

[0019] Reference Figure 1 As shown, this utility model embodiment provides an insulated capacitor, including a core 1. An insulating layer 2, a fiber layer 3 and a metal shell layer 4 are sequentially provided outside the core 1. An adhesive filling layer 5 is provided between the insulating layer 2 and the fiber layer 3, and between the fiber layer 3 and the metal shell layer 4. The fiber layer 3 includes a glass fiber mesh 31.

[0020] Specifically, the insulating layer 2 can be made of PP board, the metal shell layer 4 can be made of aluminum or iron, and the adhesive filling layer 5 can be made of polyurethane resin or epoxy resin. The encapsulation process of the capacitor in this embodiment can be as follows: first, assemble the capacitor sequentially in the order of core 1 - insulating layer 2 - fiberglass mesh 31 - metal shell layer 4; then, perform adhesive filling at the end injection port, allowing the adhesive to enter between the metal shell, fiberglass mesh 31, and insulating layer 2, filling gaps and bonding each layer together, thereby forming adhesive filling layers 5 between the insulating layer 2 and fiber layer 3, and between the fiber layer 3 and metal shell layer 4.

[0021] In this embodiment of the invention, a fiberglass mesh 31 is added between the insulating layer 2 and the metal outer shell layer 4. The fiberglass mesh 31 possesses certain tensile strength and flexibility, and after being attached to the inner wall of the metal outer shell, it can form a unified whole with the outer shell material. After the adhesive is poured in, the integrity between the metal outer shell and the adhesive surface is improved, increasing the adhesion between the adhesive filling layer 5 and the outer shell. This helps ensure a tight bond between the adhesive filling layer 5 and the outer shell, reducing the hollow phenomenon caused by differences between the metal outer shell and the adhesive material. Furthermore, during the adhesive pouring process, the outer shell is subjected to various stresses, such as the weight of the adhesive, temperature changes, and humidity changes. The fiberglass mesh 31 can disperse these stresses, preventing stress concentration in a particular area. The fiberglass mesh 31 can also improve the flexibility of the adhesive filling layer 5, allowing it to better adapt to the deformation of the shell.

[0022] Figure 2 This is a schematic diagram of the structure of the glass fiber mesh 31 in an exemplary embodiment. Optionally, the mesh density of the glass fiber mesh 31 is 16 to 100 meshes / inch, and to further enhance its adhesion to the adhesive filler layer 5, the surface of the glass fiber mesh 31 in this embodiment may have a silane coupling agent modified layer (not shown in the figure). Specifically, the glass fiber mesh 31 can be impregnated in a silane coupling agent solution, or the silane coupling agent solution can be uniformly coated on the surface of the glass fiber mesh 31, thereby forming a silane coupling agent modified layer on the surface of the glass fiber mesh 31 to enhance the interfacial bonding performance between the glass fiber mesh 31 and the adhesive filler layer 5. Exemplary silane coupling agents can be any of KH-550, KH-560, etc.

[0023] In some alternative embodiments, refer to Figure 3 As shown, the fiberglass mesh 31 is woven from a mixture of fiberglass filaments 311 and thermally conductive fiber filaments 312. In the fiberglass mesh 31, the fiberglass filaments 311 extend horizontally, while the thermally conductive fiber filaments 312 extend vertically. Specifically, the warp threads extending vertically in the fiberglass mesh 31 are thermally conductive fiber filaments 312, and the weft threads extending horizontally are fiberglass filaments 311. Because thermally conductive fibers have excellent thermal conductivity, by mixing the two types of fibers in a certain proportion, the fiberglass mesh 31 combines the mechanical strength of fiberglass with the thermal conductivity of thermally conductive fibers. The thermally conductive fiber filaments 312 are arranged along the dominant thermal direction (longitudinal direction), allowing the heat generated by the core 1 to be rapidly conducted from the central region to both ends, improving the cracking and detachment phenomenon caused by most of the heat being transferred along the thickness direction to the adhesive filler layer 5. The fiberglass filaments 311 provide lateral reinforcement, further improving the adhesion between the adhesive filler layer 5 and the metal shell.

[0024] Optionally, the volume content of thermally conductive fiber filaments 312 in the glass fiber mesh 31 can be 20 to 40 vol%. Specifically, the thermally conductive fiber filaments 312 may include insulating fiber materials with excellent thermal conductivity, such as boron nitride fiber filaments, aluminum nitride fiber filaments, and alumina fiber filaments.

[0025] Figure 4 This is a schematic diagram of the structure of the fiber layer 3 in another exemplary embodiment. For simplicity, the adhesive filler layer 5 between each adjacent layer has been omitted. In this optional embodiment, refer to... Figure 4 As shown, the fiber layer 3 may further include a thermally conductive fiber mesh 32. The number of glass fiber meshes 31 is at least two layers, and the thermally conductive fiber mesh 32 is disposed between at least two layers of glass fiber meshes 31, forming a sandwich structure with overlapping layers. The thermally conductive fiber mesh 32 can be woven from thermally conductive fiber filaments 312 simultaneously along both the warp and weft directions. In this embodiment, the glass fiber mesh 31 on the outer layer of the sandwich structure improves the adhesion between the adhesive filler layer 5 and the metal outer shell layer 4 and the insulating layer 2, while the thermally conductive fiber mesh 32 in the middle of the sandwich structure provides thermal conductivity. It has a larger thermally conductive area and can conduct heat along the entire in-plane direction, further accelerating the heat dissipation capacity of the capacitor.

[0026] Figure 5 This is a schematic diagram of the structure of the fiber layer 3 in another exemplary embodiment, in which all adhesive filler layers 5 are also omitted. In this optional embodiment, refer to... Figure 5 As shown, the insulating capacitor also includes a buffer layer 6, and the number of glass fiber mesh 31 is at least two layers, with the buffer layer 6 disposed between at least two glass fiber meshes 31. Due to the large difference in the coefficients of thermal expansion between the metal casing and the filler adhesive, shear stress is easily generated at the interface during temperature cycling. In this embodiment, the glass fiber mesh 31 and the buffer layer 6 also form a sandwich structure. The buffer layer 6 can absorb the expansion difference between the metal casing and the filler adhesive through its low modulus and reversible deformation, reducing the shear stress by 60% to 80%, thereby inhibiting resin cracking or peeling of the glass fiber mesh 31. Specifically, the material of the buffer layer 6 can be rubber or polyimide.

[0027] In some alternative embodiments, such as Figure 5 As shown, the buffer layer 6 may be mesh-like, or, in other embodiments, the buffer layer 6 may extend in a wavy shape along the length or width direction of the fiber layer 3.

[0028] To further improve the adhesion between the adhesive filler layer 5 and the metal outer shell layer 4, in some optional embodiments, the fiberglass mesh 31 can be mechanically connected to the metal outer shell layer 4. Exemplarily, the fiberglass mesh 31 can be detachably connected to the metal outer shell layer 4, specifically by fixing it to the inner wall of the metal outer shell layer 4 with insulating nails or rivets; alternatively, the fiberglass mesh 31 can be first bonded to the inner wall of the metal outer shell layer 4 and cured, and then adhesive can be injected for encapsulation. Alternatively, refer to... Figure 6 As shown, the upper and lower ends of the fiberglass mesh 31 extend to the two open ends of the metal outer shell layer 4, and the upper and lower ends of the fiberglass mesh 31 have flanges 313 bent toward the metal outer shell layer 4, and each flange 313 is pressed and connected to one of the open ends of the metal outer shell layer 4.

[0029] By forming the aforementioned mechanical connection between the fiberglass mesh 31 and the metal outer shell layer 4, the relative position of the fiberglass mesh 31 is fixed, which helps to prevent displacement during the glue injection process, thereby further improving the adhesion between the resin material and the metal outer shell layer 4, further forming a resin sealing barrier, and preventing blistering or detachment.

[0030] Furthermore, in some optional embodiments, the inner wall of the metal outer shell layer 4 may be provided with a plurality of uniformly distributed grooves or protrusions, the groove depth or protrusion height may be 0.05mm to 0.3mm. The present invention roughens the inner wall of the metal outer shell layer 4 by means of grooves or protrusions, which is beneficial to further enhance its mechanical anchoring force for the filling adhesive.

[0031] The following discloses exemplary embodiments of the present invention: Example 1 like Figure 1 and Figure 2 As shown, this embodiment provides an insulated capacitor, including a core 1. An insulating layer 2, a fiber layer 3, and a metal shell layer 4 are sequentially disposed outside the core 1. Adhesive filling layers 5 are provided between the insulating layer 2 and the fiber layer 3, and between the fiber layer 3 and the metal shell layer 4. The fiber layer 3 is a glass fiber mesh 31.

[0032] In this embodiment, the insulating layer 2 is made of PP board, the metal outer shell layer 4 is made of aluminum, the adhesive filling layer 5 is made of polyurethane resin, and the fiberglass mesh 31 has a mesh density of 80 meshes / inch.

[0033] In this embodiment, the glass fiber mesh 31 is a glass fiber mesh 31 treated with a silane coupling agent, that is: the glass fiber mesh 31 is immersed in a silane coupling agent solution to form a surface modified layer on the surface of the glass fiber mesh 31. The silane coupling agent is specifically KH-550.

[0034] In this embodiment, the fiberglass mesh 31 is fixed to the inner wall of the metal outer shell layer 4 by insulating nails. The insulating nails are distributed at the four corners of the fiberglass mesh 31. The inner wall of the metal outer shell layer 4 is uniformly provided with a plurality of protrusions with a height range of 0.05mm to 0.3mm to further enhance the mechanical anchoring force between the adhesive filling layer 5 and the metal outer shell layer 4.

[0035] In this embodiment, by adding a glass fiber mesh 31 between the insulating layer 2 and the metal outer shell layer 4, the glass fiber mesh 31, which has certain tensile strength and flexibility, can form a whole with the outer shell material after being attached to the inner wall of the metal outer shell and forming a mechanical connection. Therefore, after the glue is injected, the integrity between the metal outer shell and the glue surface can be improved, thereby increasing the adhesion between the glue filling layer 5 and the outer shell, helping to ensure that the glue filling layer 5 is tightly bonded to the outer shell, and reducing the hollow phenomenon caused by the difference between the metal outer shell and the glue material.

[0036] Example 2 like Figure 3 As shown, the difference between this embodiment and Embodiment 1 is that the glass fiber mesh 31 in this embodiment is woven from a mixture of glass fiber filaments 311 and thermally conductive fiber filaments 312. The glass fiber filaments 311 extend horizontally (weft), and the thermally conductive fiber filaments 312 extend vertically (warp). The volume content of the thermally conductive fiber filaments 312 is 40 vol%. Specifically, the thermally conductive fiber filaments 312 are boron nitride fibers.

[0037] In this embodiment, by mixing the two types of fibers in a certain proportion, the glass fiber mesh 31 can combine the mechanical strength of glass fiber with the thermal conductivity of thermally conductive fiber. The thermal conductivity of the thermally conductive fiber filament 312 allows the heat generated by the core 1 to be rapidly conducted from the central region to both ends, improving the situation where most of the heat is transferred along the thickness direction to the adhesive filler layer 5, which can cause cracking and detachment.

[0038] Example 3 like Figure 4 As shown, the difference between this embodiment and Embodiment 1 is that the fiber layer 3 in this embodiment includes a thermally conductive fiber mesh 32 and two layers of glass fiber mesh 31. The thermally conductive fiber mesh 32 is disposed between the two glass fiber meshes 31, forming a sandwich structure with the two layers stacked on top of each other. The thermally conductive fiber mesh 32 is woven from boron nitride fibers simultaneously along the warp and weft directions.

[0039] In this embodiment, the thermally conductive fiber mesh 32 in the middle of the sandwich structure provides thermal conductivity. It has a larger thermally conductive area and can conduct heat along the entire in-plane direction, further accelerating the heat dissipation of the capacitor.

[0040] Example 4 like Figure 5 As shown, the difference between this embodiment and Embodiment 1 is that the insulating capacitor in this embodiment further includes a buffer layer 6, and the fiber layer 3 includes two layers of glass fiber mesh 31. The buffer layer 6 is disposed between the two glass fiber mesh 31 to form a sandwich structure. The material of the buffer layer 6 is rubber, and the buffer layer 6 extends in a wavy shape along the length direction of the fiber layer 3.

[0041] In this embodiment, the buffer layer 6 absorbs the expansion difference between the metal shell and the filler adhesive through its low modulus and reversible deformation, thereby reducing shear stress and further suppressing resin cracking or peeling of the glass fiber mesh 31.

[0042] Although the present invention has been disclosed above, its protection scope is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the protection scope of the present invention.

Claims

1. An insulated capacitor, comprising a core (1), characterized in that, The core (1) is provided with an insulating layer (2), a fiber layer (3) and a metal shell layer (4) in sequence. There is an adhesive filling layer (5) between the insulating layer (2) and the fiber layer (3) and between the fiber layer (3) and the metal shell layer (4). The fiber layer (3) includes a glass fiber mesh (31).

2. The insulated capacitor according to claim 1, characterized in that, The surface of the glass fiber mesh (31) has a silane coupling agent modified layer.

3. The insulated capacitor according to claim 1, characterized in that, The glass fiber mesh (31) is woven from a mixture of glass fiber filaments (311) and thermally conductive fiber filaments (312). In the glass fiber mesh (31), the glass fiber filaments (311) extend in the horizontal direction, and the thermally conductive fiber filaments (312) extend in the vertical direction.

4. The insulated capacitor according to claim 1, characterized in that, The fiber layer (3) further includes a thermally conductive fiber mesh (32), and the number of glass fiber mesh (31) is at least two layers, with the thermally conductive fiber mesh (32) disposed between at least two layers of glass fiber mesh (31).

5. The insulated capacitor according to claim 1, characterized in that, It also includes a buffer layer (6), the fiber layer (3) comprising at least two layers of the glass fiber mesh (31), the buffer layer (6) being disposed between the at least two layers of the glass fiber mesh (31).

6. The insulated capacitor according to claim 5, characterized in that, The buffer layer (6) is mesh-like.

7. The insulated capacitor according to claim 5, characterized in that, The buffer layer (6) extends in a wavy shape along the length or width of the fiber layer (3).

8. The insulated capacitor according to claim 1, characterized in that, The glass fiber mesh (31) and the metal outer shell layer (4) can be detachably connected or pressed together.

9. The insulated capacitor according to claim 8, characterized in that, The upper and lower ends of the glass fiber mesh (31) extend to the two open ends of the metal outer shell layer (4), and the upper and lower ends of the glass fiber mesh (31) have flanges (313) bent toward the metal outer shell layer (4), and each flange (313) is pressed and connected to one of the open ends of the metal outer shell layer (4).

10. The insulated capacitor according to claim 1, characterized in that, The inner wall of the metal outer shell layer (4) is provided with a plurality of uniformly distributed grooves or protrusions.

Images