A new type of high-voltage safety explosion-proof coated capacitor shell

Abstract

The utility model relates to a novel high -pressure safety explosion -proof film -coated capacitor shell, its characterized in that: the shell includes aluminium base layer, film layer, the shell inside is provided with the cavity for accommodating nucleon, the cavity one end is provided with the opening, the aluminium base layer outer peripheral surface covers film layer, film layer and aluminium base layer outer peripheral surface are combined integrally and form the shell. Through adopting a kind of to melt liquid state coating hot-pressing formation in aluminium base layer obtains novel high -pressure safety explosion -proof film -coated shell, solves the technical bottleneck of the existing solid-state film pasting process, can obviously improve the peel strength between film layer and aluminium base layer, solves the problem that film layer appears to fall off or bulge on the surface of aluminium shell in processing or high temperature environment, reduces process yield. It can be applied to the high -voltage aluminium electrolytic capacitor of voltage greater than 400V, is applicable to AI server, electric automobile, photovoltaic energy storage, communication equipment, artificial intelligence and other national strategic emerging industries have extensive market demand.

Description

Technical Field

[0001] This utility model relates to the field of aluminum electrolytic capacitor technology, and in particular to a novel high-voltage safety explosion-proof coated capacitor shell. Background Technology

[0002] Currently, the mainstream aluminum electrolytic capacitor industry uses coated aluminum shells, which are generally suitable for low-voltage capacitors. For high-voltage capacitors, the industry prefers to use ordinary aluminum shells with external heat-shrink tubing as the external insulation structure and the carrier for printed product information. A mature process in the industry is the lamination process, which involves bonding a pre-produced solid PET film layer to an aluminum plate and then drawing it into an aluminum shell. This is mostly used for low-voltage capacitors. The biggest drawback of this lamination process in the aluminum electrolytic capacitor industry is the poor adhesion between the film layer and the aluminum plate, making it unsuitable for high-voltage capacitors. Furthermore, surface blistering, delamination, and film tearing are prone to occur during manufacturing and application. Utility Model Content

[0003] Therefore, it is necessary to provide a novel high-voltage safety explosion-proof coated capacitor housing to solve the technical problems mentioned in the background art.

[0004] The technical problem solved by this utility model is achieved through the following technical solution: A novel high-voltage safety explosion-proof coated capacitor housing is characterized in that: the housing comprises an aluminum base layer and a film layer; the housing has an internal cavity for accommodating elements, and one end of the cavity has an opening; the outer peripheral surface of the aluminum base layer is covered with the film layer; the film layer and the outer peripheral surface of the aluminum base layer are integrally bonded to form the housing.

[0005] Preferably, the film layer is formed by hot pressing of a molten liquid PET extrusion coating.

[0006] Preferably, the film layer is at least one layer or more.

[0007] Preferably, the thickness of the film layer is 0.01mm-0.3mm.

[0008] Preferably, the outer top of the housing is provided with an explosion-proof structure.

[0009] Preferably, the explosion-proof structure is formed by stamping with specific guide tear notches in the shape of a cross or a Y.

[0010] Preferably, the film layer is formed by electroplating.

[0011] Preferably, the housing is used for encapsulation in aluminum electrolytic capacitors.

[0012] The advantages and positive effects of this invention are as follows: By employing a novel high-voltage safety explosion-proof coated shell formed by hot-pressing a molten liquid coating onto an aluminum substrate, this invention overcomes the technical bottlenecks of existing solid-state lamination processes. It significantly improves the peel strength between the film layer and the aluminum substrate, resolving issues such as film peeling or bulging on the aluminum shell surface during processing or in high-temperature environments, thus reducing the process defect rate. This invention can be applied to high-voltage aluminum electrolytic capacitors with voltages greater than 400V, and is suitable for use in national strategic emerging industries such as AI servers, electric vehicles, photovoltaic energy storage, communication equipment, and artificial intelligence, with broad market demand. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the cross-sectional structure of the shell of this utility model.

[0015] Figure 2 This is a utility model Figure 1 A magnified view of part A in the diagram.

[0016] Figure 3 This is a three-dimensional structural diagram of the shell of this utility model.

[0017] Figure 4 This is a top view of the shell structure of this utility model.

[0018] Figure 5 This is a schematic diagram of the cross-sectional structure of an aluminum electrolytic capacitor using the housing of this utility model.

[0019] Explanation of reference numerals: 1. Shell; 101. Aluminum base layer; 102. Film layer; 103. Explosion-proof structure; 104. Cavity; 105. Opening; 2. Element; 3. Sealing cover; 4. Positive lead; 5. Negative lead; 6. Waist-binding structure. Detailed Implementation

[0020] The embodiments of this utility model will be further described in detail below with reference to the accompanying drawings: The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this utility model or its application or use. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. In the description of this utility model, it should be understood that the terms "upper," "lower," "bottom," "inner," "outer," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings are industry-specific structural names for leads, and are only for the convenience of describing this utility model 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, and therefore should not be construed as a limitation of this utility model. Example

[0021] A novel high-voltage safety explosion-proof coated capacitor housing is characterized in that: the housing 1 includes an aluminum base layer 101 and a film layer 102; the housing 1 has a cavity 104 for accommodating elements 2 inside, and one end of the cavity 104 has an opening 105; the outer peripheral surface of the aluminum base layer 101 is covered with the film layer 102; the film layer 102 and the outer peripheral surface of the aluminum base layer 101 are integrally formed to form the housing 1.

[0022] like Figure 1 As shown, the housing 1 includes an aluminum base layer 101 and a film layer 102 covering the outer surface of the aluminum base layer 101. The cavity 104 of the housing 1 is used to encapsulate the element 2 of the aluminum electrolytic capacitor and the electrolyte.

[0023] The aluminum base layer 101 is preferably made of an aluminum alloy with moderate hardness and good ductility. The film layer 102 is made of an insulating material. In this embodiment, the main material of the insulating film layer of the film layer 102 is polyethylene terephthalate (PET).

[0024] Film layer 102 is formed by hot pressing of molten liquid PET extrusion coating. The bonding process between aluminum substrate 101 and film layer 102 involves melting and plasticizing the main insulating film material at high temperature, and extruding it through a die to form a molten film of uniform thickness. The extruded molten PET film is then immediately brought into contact with the preheated surface of aluminum substrate 101, allowing the molten PET to fully wet the surface of aluminum substrate 101 and form a composite, resulting in an aluminum plate with aluminum substrate 101 as the base and film layer 102 covering it. The number of layers of film layer 102 on the surface of aluminum substrate 101 is at least one, and the thickness of film layer 102 can be set according to actual needs. The thickness of film layer 102 is preferably 0.01mm-0.3mm. This thickness range ensures the insulation performance of film layer 102 while avoiding the impact on the size and assembly of the capacitor due to excessive thickness.

[0025] The core of this structural process lies in directly bonding the PET film layer to a preheated aluminum plate under pressure while it is in a molten state. After hot pressing, the micropores on the surface of the aluminum plate are filled with molten PET, forming a strong, dense, and gapless composite structure. This is the foundation for achieving the processing of the outer explosion-proof structure and overall high performance, and it can significantly improve the peel strength between the film layer 102 and the aluminum base layer 101. It solves the problem of film layer peeling or bulging on the surface of the aluminum base layer 101 in the high-temperature environment of shell 1 processing or reflow soldering.

[0026] The coated aluminum sheet obtained above is processed into an aluminum shell blank with a specified diameter and height through a multi-pass deep drawing process. The inner side is an aluminum base layer 101 and the outer side is a PET insulating film layer 102, thus obtaining the explosion-proof coated capacitor shell 1.

[0027] like Figure 5 As shown, the element 2 is assembled and packaged. Specifically, the element 2, impregnated with electrolyte, is placed into the cavity 104 of the housing 1. The element 2 has a positive terminal 4 and a negative terminal 5 connected to it. A sealing cap 3 is inserted into the opening 105 of the housing 1, with the positive terminal 4 and negative terminal 5 protruding outwards through the sealing cap 3. The sealing cap 3 seals the element 2 within the cavity 104 of the housing 1. Simultaneously, a waisting and necking structure is applied to the contact area between the housing 1 and the sealing cap 3, further enhancing the sealing effect between the sealing cap 3 and the housing 1. This results in a novel high-voltage safety explosion-proof coated capacitor.

[0028] The shell 1, designed with a high-temperature melt coating structure, adopts a new type of high-pressure safety explosion-proof coated aluminum shell produced by a hot-pressing process using molten liquid PET extrusion coating. This solves the technical bottleneck of the existing solid film bonding process, significantly improves the bonding force between the film layer 102 and the aluminum base layer 101, and significantly improves the peel strength between the film layer 102 and the aluminum base layer 101. It solves the problem of film peeling or bulging on the surface of the aluminum base layer 101 during processing or high-temperature environments, reduces the process defect rate, and effectively improves the problem of the film being lifted and torn into fine strip-shaped burrs by the high-speed rotation of the waist sealing wheel of the processing machine during the waist sealing process of aluminum electrolytic capacitor assembly packaging, which seriously affects the appearance integrity and insulation. Example

[0029] Example 2 is based on Example 1, with an explosion-proof structure 103 provided on the top outer side of the housing 1. The explosion-proof structure 103 is composed of a notch 1031 with a cross-shaped or Y-shaped guide tear formed by stamping. In addition, the film layer 102 can also be formed by electroplating. This significantly improves the bonding force between the film layer 102 and the aluminum base layer 101, while better repairing the structure and adhesion of the film layer 102 at the explosion-proof structure 103.

[0030] During operation, the internal temperature of an aluminum electrolytic capacitor may rise or gas may be generated inside, causing the internal pressure of the aluminum electrolytic capacitor to increase. When the pressure exceeds the preset value, the aluminum electrolytic capacitor will burst.

[0031] In traditional coated housings, the explosion-proof structure 103 is located on the inner side of the housing 1. Currently, in the industry, during the deep-drawing process of aluminum substrate 101, to maintain the integrity and cleanliness of the film layer 102, the explosion-proof structure 103 is typically designed on the inner side of the housing 1, not in direct contact with the film layer 102. However, in this configuration, when the internal gas pressure of the aluminum electrolytic capacitor reaches a critical value, the bottom of the housing 1 deforms and bulges, reducing the inner gap, while the outer side, lacking a designed gap, cannot guide the aluminum substrate 101 to gradually tear. The explosion-proof structure 103 is ultimately forced open in a violent manner, resulting in a large opening gap in length and width. For aluminum electrolytic capacitor products with high design voltages, this inner explosion-proof structure makes the critical opening pressure of the housing 1 high, difficult to reduce to the design requirement value, and the opening process is usually more violent, easily causing the electrolytic paper to be exposed and the electrolyte to splash onto the circuit board, leading to a short circuit and more serious failure accidents.

[0032] Embodiment 2 of this utility model employs an external explosion-proof structure 103, providing safe and reliable explosion protection. Benefiting from the strong bond between the PET film layer 102 and the aluminum base layer 101 under the extrusion coating hot pressing process, the degree of damage to the film layer 102 during the processing of the external explosion-proof structure 103 is relatively low, and the burr length at the processing point is less than 0.05mm, providing feasibility for successfully realizing the "external explosion-proof" design of the coated aluminum shell. The valve opening pressure can be reduced to a range that is difficult to achieve with an internal explosion-proof valve. The valve opening form is a gentle "center-point explosion," with a small and regular opening, without excessive exposure of electrolytic paper or violent splashing of electrolyte, meeting the safety requirements for capacitor use, and is especially suitable for high-voltage and high-reliability applications.

[0033] It should be emphasized that the embodiments described in this utility model are illustrative rather than limiting. Therefore, this utility model is not limited to the embodiments described in the specific implementation. Any other implementation methods derived by those skilled in the art based on the technical solutions of this utility model are also within the scope of protection of this utility model.

Claims

1. A novel high-voltage safety explosion-proof coated capacitor housing, characterized in that: The shell (1) includes an aluminum base layer (101) and a film layer (102); the shell (1) has a cavity (104) for accommodating the element (2) inside, and an opening (105) is provided at one end of the cavity (104); the outer peripheral surface of the aluminum base layer (101) is covered with the film layer (102); the film layer (102) and the outer peripheral surface of the aluminum base layer (101) are integrated to form the shell (1).

2. The novel high-voltage safety explosion-proof coated capacitor housing according to claim 1, characterized in that: The film layer (102) is formed by hot pressing of molten liquid PET extrusion coating.

3. The novel high-voltage safety explosion-proof coated capacitor housing according to claim 1, characterized in that: The membrane layer (102) is at least one layer.

4. The novel high-voltage safety explosion-proof coated capacitor housing according to claim 1, characterized in that: The thickness of the membrane (102) is 0.01mm-0.3mm.

5. A novel high-voltage safety explosion-proof coated capacitor housing according to claim 1, characterized in that: An explosion-proof structure (103) is provided on the outer side of the top of the housing (1).

6. A novel high-voltage safety explosion-proof coated capacitor housing according to claim 5, characterized in that: The explosion-proof structure (103) is composed of a notch (1031) formed by stamping with a specific guide tear in the shape of a cross or a Y.

7. A novel high-voltage safety explosion-proof coated capacitor housing according to claim 1, characterized in that: The film layer (102) is formed by electroplating.

8. A novel high-voltage safety explosion-proof coated capacitor housing according to claim 1, characterized in that: The housing (1) described in claims 1-7 is used for encapsulation in aluminum electrolytic capacitors.

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