Thin film capacitor

Abstract

The invention provides a thin-film capacitor. The thin-film capacitor comprises a shell, an injection molding structure body, a sealing element and a potting material, a mounting cavity with an open top is defined by the shell, a notch communicated with the mounting cavity is formed in one side of the shell, the injection molding structural body is integrally formed by a core and an extraction electrode in an injection molding mode, and the injection molding structural body is embedded into the notch and distributed inside and outside the mounting cavity. A notch is formed in the injection molding structure body, a mounting groove matched with the outline of the notch is formed in the injection molding structure body, the sealing piece is mounted in the mounting groove and is in contact with the notch, so that the injection molding structure body is sealed at the notch, and the potting material is encapsulated in the mounting cavity. The thin film capacitor is simple in structure, can reduce the cost, improves the production efficiency, and guarantees the sealing consistency.

Description

Technical Field

[0001] This invention relates to the field of capacitor technology, and more specifically to a thin-film capacitor. Background Technology

[0002] Film capacitors are widely used in electronic equipment, industrial control, and automotive industries. They mainly consist of a capacitor core, lead electrodes, a casing, an injection-molded structure, and filling resin. For sealed film capacitors with an internal injection-molded structure, leakage is prone to occur at the mating points between the injection-molded structure and the casing during resin filling. Existing technologies require either adhesive sealing or adding a silicone coating process to the injection-molded part to solve this problem. However, because the complex injection-molded structure cannot directly form a seal with the casing, adhesive sealing requires slotting the casing and manual adhesive application, resulting in low production efficiency, high process costs, and poor consistency in adhesive application. Silicone coating of the injection-molded part adds an extra process step and carries the risk of poor coating quality, making it difficult to consistently meet the requirements for leak prevention. Existing leak prevention solutions cannot simultaneously achieve both production efficiency and sealing reliability. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the aforementioned technologies. Therefore, the object of the present invention is to provide a thin-film capacitor that has a simple structure, reduces costs, improves production efficiency, and ensures consistent sealing.

[0004] To achieve the above objectives, the present invention provides a thin-film capacitor, comprising a housing, an injection-molded structure, a sealant, and a potting compound; The outer shell defines a top-open mounting cavity, and one side of the outer shell has a notch communicating with the mounting cavity. The injection-molded structure is integrally injection-molded from a core and an lead electrode. The injection-molded structure is embedded in the notch and distributed inside and outside the mounting cavity. The injection-molded structure is formed with a mounting groove that matches the contour of the notch. The seal is installed in the mounting groove and contacts the notch so that the injection-molded structure forms a seal at the notch. The potting compound is filled into the mounting cavity.

[0005] According to the present invention, a thin-film capacitor eliminates the traditional method of slotting the outer casing and manually applying adhesive. Instead, a mounting groove adapted to the notch contour is integrally formed on the injection-molded structure that mates with the notch in the outer casing. By installing a sealing element within the mounting groove and ensuring its contact with the notch in the outer casing, a sealing structure is formed at the interface between the injection-molded structure and the outer casing, achieving a leak-proof effect during potting. Furthermore, no additional adhesive application or encapsulation process is required. This thin-film capacitor has a simple structure, reduces costs, improves production efficiency, and ensures consistent sealing.

[0006] In addition, a thin-film capacitor according to the above embodiments of the present invention may also have the following additional technical features: Optionally, both ends of the mounting groove are provided with bayonets, and the two ends of the seal are respectively inserted into the two bayonets.

[0007] Furthermore, the sealing element is provided with limiting ends at both ends, which are used to abut against the end face of the bayonet so that the sealing element is installed in the mounting groove.

[0008] Optionally, the seal is made of a soft sealing material, which is one or more of silicone, rubber, thermoplastic elastomer (TPE), or thermoplastic polyurethane elastomer (TPU).

[0009] Optionally, the lead electrode is one of a lead wire, a solder pad, or a busbar.

[0010] Optionally, there are at least two cores, the lead-out electrodes are disposed in each core, and the mounting groove is disposed between two adjacent cores. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of a thin-film capacitor according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the injection-molded structure and seal according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the outer casing according to an embodiment of the present invention; Explanation of reference numerals in the attached figures: 1. Outer shell, 11. Mounting cavity, 12. Notch, 2. Injection molded structure, 21. Core, 22. Lead electrode, 23. Plastic shell, 24. Mounting groove, 25. Bayonet, 3. Seal, 31. Limiting end, 4. Encapsulating material. Detailed Implementation

[0012] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0013] To better understand the above technical solutions, 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 drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the invention to those skilled in the art.

[0014] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0015] The following is for reference. Figures 1-3 The implementation of the thin-film capacitor proposed in the embodiments of the present invention will be described in detail.

[0016] According to an embodiment of the present invention, a thin-film capacitor includes: a housing 1, an injection-molded structure 2, a sealing element 3, and a potting compound 4; The outer shell 1 defines an open mounting cavity 11, and one side of the outer shell 1 is provided with a notch 12 communicating with the mounting cavity 11. The injection molded structure 2 is integrally injection molded from the core 21 and the lead electrode 22. The injection molded structure 2 is embedded in the notch 12 and distributed inside and outside the mounting cavity 11. The injection molded structure 2 is formed with a mounting groove 24 that matches the contour of the notch 12. The seal 3 is installed in the mounting groove 24 and contacts the notch 12 so that the injection molded structure 2 forms a seal at the notch 12. The potting compound 4 is filled into the mounting cavity 11.

[0017] In other words, the core 21 and the lead electrode 22 are integrally injection molded, and the surface is covered with a plastic shell 23 to form an injection molded structure 2. The injection molded structure 2 has an integrally formed mounting groove 24 for installing the seal 3. After the seal 3 is assembled with the injection molded structure 2, it is embedded into the notch 12 of the shell 1, so that part of the injection molded structure 2 is inside the mounting cavity 11 and the other part is outside the mounting cavity 11. The seal 3 contacts the mounting groove 24 and the notch 12 to form a seal between the inside and outside of the mounting cavity 11, so as to prevent the potting material 4 from leaking out of the mounting cavity 11 from the notch 12 when the mounting cavity 11 is potted. This capacitor eliminates the leakage prevention methods of existing technologies, such as slotting the outer shell 1, manually applying glue, or encapsulating silicone in injection molded parts. Instead, it achieves sealing through the mounting groove 24 integrated into the injection molded structure 2 and the sealing element 3. The outer shell 1 requires no slotting, and no glue is needed at the mating points. The sealing element 3 and the injection molded structure 2 have a mechanical fit, allowing for direct potting to complete assembly. This effectively solves the problems of low efficiency, high cost, and poor sealing consistency in existing leakage prevention methods, while providing stable sealing performance. It is suitable for the use of film capacitors in electronic equipment, industrial control, automotive, and other fields. The sealing element 3 can be tightly fitted into the mounting groove 24. The cross-section of the sealing element 3 can be square or circular, and the notch 12 can be U-shaped. The surface of the notch 12 that contacts the sealing element 3 can be adapted to the contour of the sealing element 3.

[0018] Therefore, this film capacitor abandons the traditional method of slotting the outer casing 1 and manually applying adhesive. Instead, a fitting mounting groove 24 is integrally formed on the injection-molded structure 2 that mates with the notch 12 of the outer casing 1. By installing a sealing element 3 within the mounting groove 24 and ensuring its contact with the notch 12 of the outer casing 1, a sealing structure is formed at the mating point between the injection-molded structure 2 and the outer casing 1, achieving a leak-proof effect during potting. Furthermore, no additional adhesive application or encapsulation process is required. This film capacitor has a simple structure, reduces costs, improves production efficiency, and ensures consistent sealing.

[0019] Optionally, both ends of the mounting groove 24 are provided with snap-fit ​​slots 25, and the two ends of the seal 3 are correspondingly snapped into the two snap-fit ​​slots 25. Understandably, providing snap-fit ​​slots 25 at both ends of the mounting groove 24 and allowing the ends of the seal 3 to snap into them is to achieve mechanical positioning and fixation between the seal 3 and the mounting groove 24, replacing the traditional adhesive fixing method. The contour of the snap-fit ​​slots 25 matches the ends of the seal 3, allowing the seal 3 to be quickly snapped into place, preventing displacement or loosening of the seal 3 during the potting process, and ensuring that the seal 3 is always in close contact with the notch 12 of the outer shell 1. This structural design requires no additional fasteners, facilitates assembly, and ensures the consistency of the seal 3's installation position, further improving the stability and assembly efficiency of the overall sealing structure. The snap-fit ​​slots 25 can be integrally molded during injection molding, and can be C-shaped.

[0020] Furthermore, the seal 3 is provided with limiting ends 31 at both ends. The limiting ends 31 are used to abut against the end face of the bayonet 25 so that the seal 3 can be installed in the mounting groove 24. Understandably, the size of the limiting ends 31 is larger than the inner diameter of the bayonet 25. The mutual abutment between the limiting ends 31 at both ends of the seal 3 and the end face of the bayonet 25, as well as the elasticity of the seal 3 itself, allows the seal 3 to fit tightly in the mounting groove 24, making the contact between the seal 3 and the mounting groove 24 and the notch 12 of the outer shell 1 more compact, thus improving the sealing effect. At the same time, this limiting structure is an integrated design, requiring no additional adjustment, which simplifies the assembly steps and ensures the standardization of the installation of the seal 3 during mass production.

[0021] Optionally, the seal 3 is made of a soft sealing material, which may be one or more of silicone, rubber, thermoplastic elastomer (TPE), or thermoplastic polyurethane elastomer (TPU). Understandably, by selecting soft sealing materials such as silicone and rubber, and utilizing their inherent elastic deformation properties, the seal 3 can fit more tightly with the mounting groove 24 and the notch 12 of the outer shell 1, filling tiny gaps at the mating points and achieving a good sealing and leak-proof effect, suitable for the pressure environment during potting. These materials possess good temperature resistance and chemical corrosion resistance, adapting to the environment in which the capacitor operates and the chemical properties of the potting compound 4, and are not prone to aging or deformation. Multiple materials are available, allowing for flexible combinations based on the capacitor's application scenario and cost requirements, balancing sealing performance and practicality.

[0022] Optionally, the lead electrode 22 can be one of a lead wire, a solder pad, or a busbar. Understandably, the choice of lead wire, solder pad, or busbar for the lead electrode 22 is to adapt to the wiring requirements of capacitors in different application scenarios. Lead wires are suitable for miniaturized and lightweight electronic devices, solder pads facilitate circuit board soldering and fixing, and busbars are suitable for high-current, high-power industrial control, automotive, and other fields. This design makes the wiring method of the film capacitor more flexible, enabling it to match different circuit systems. It eliminates the need to redesign the injection-molded structure 2 for different wiring requirements; only the lead electrode 22 needs to be replaced, reducing product development and manufacturing costs and improving product adaptability and versatility.

[0023] Optionally, at least two cores 21 are provided, with lead electrodes 22 passing through each core 21, and mounting slots 24 located between adjacent cores 21. Understandably, placing the mounting slots 24 between adjacent cores 21 fully utilizes the space of the injection-molded structure 2, making the overall structure more compact and avoiding an increase in capacitor size due to the mounting slots 24, thus conforming to the design trend of capacitor miniaturization. The lead electrodes 22 passing through each core 21 achieve electrical connection. With the mounting slots 24 in this location, the seal 3 does not affect the electrical connection performance between the cores 21 and the lead electrodes 22, and also allows the sealing structure and the core capacitor components to form an integrated layout. The multi-core design 21 can improve the electrical performance of the capacitor, while the mounting slot 24 layout allows the sealing design and electrical performance design to be compatible, balancing practicality and functionality.

[0024] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," 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.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0029] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A thin-film capacitor, characterized in that, include: Housing, injection molded structure, seals and potting compound; The outer shell defines a top-open mounting cavity, and one side of the outer shell has a notch communicating with the mounting cavity. The injection-molded structure is integrally injection-molded from a core and an lead electrode. The injection-molded structure is embedded in the notch and distributed inside and outside the mounting cavity. The injection-molded structure is formed with a mounting groove that matches the contour of the notch. The seal is installed in the mounting groove and contacts the notch so that the injection-molded structure forms a seal at the notch. The potting compound is filled into the mounting cavity.

2. The thin-film capacitor as claimed in claim 1, characterized in that, Both ends of the mounting groove are provided with bayonets, and the two ends of the seal are inserted into the two bayonets in a corresponding manner.

3. The thin-film capacitor as described in claim 2, characterized in that, The sealing element is further provided with limiting ends at both ends, which are used to abut against the end face of the bayonet so that the sealing element is installed in the mounting groove.

4. The thin-film capacitor as claimed in claim 1, characterized in that, The seal is made of a soft sealing material, which is one or more of silicone, rubber, thermoplastic elastomer (TPE), or thermoplastic polyurethane elastomer (TPU).

5. The thin-film capacitor as claimed in claim 1, characterized in that, The lead-out electrode is one of the following: lead wire, solder pad, or busbar.

6. The thin-film capacitor as claimed in claim 1, characterized in that, The core has at least two, the lead electrode is inserted through each core, and the mounting groove is located between two adjacent cores.

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