Heat dissipation structure of thin film capacitor and vehicle-mounted capacitor

Abstract

The heat dissipation structure comprises a core group used for storing electric charges and further comprises an electric connecting piece used for being electrically connected with the core group, the core group comprises a plurality of cores arranged in parallel, the electric connecting piece is attached to the electrode side of the core group and forms a heat exchange end so as to conduct out heat in the core group, and the electric connecting piece is used for being electrically connected with the core group. One side, deviating from the core, of the electric connecting piece is provided with an insulating layer, and the heat exchange end protrudes out of the insulating layer to form an active heat dissipation device, so that each core of the thin film capacitor can be quickly and timely subjected to effective heat dissipation to prevent the temperature of a hot spot in the core from being too high, the capacitance is further prevented from being quickly attenuated, and the service life of the thin film capacitor is ensured; the utility model has good thermal management capability, and can effectively avoid the thermal failure phenomenon.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of power electronic components, especially relates to a heat dissipation structure of film capacitor and vehicle-mounted capacitor. BACKGROUND

[0002] Film capacitor is a kind of capacitor using plastic film as dielectric, with no polarity, high insulation resistance, excellent frequency characteristics and low dielectric loss, etc., and generally uses metal layer as electrode, and then overlaps it with plastic film from both ends, and winds into cylindrical structure core.

[0003] The current vehicle metalized film capacitor is used in high-frequency and high-temperature environment, since the core is wrapped by low-thermal-conductivity epoxy encapsulation and shell, if each core generates a large amount of heat when working, the heat inside cannot be quickly and timely conducted or dissipated due to the heat insulation effect of epoxy encapsulation and shell, which causes the temperature of the heat spot inside to be too high, and further causes the rapid attenuation of capacitance and the reduction of service life. SUMMARY

[0004] Therefore, the utility model provides a heat dissipation structure of film capacitor and vehicle-mounted capacitor to effectively dissipate heat from the core of the film capacitor in time to prevent the temperature of the heat spot inside from being too high.

[0005] To achieve the above purpose, the utility model provides the technical scheme as follows:

[0006] The utility model provides a heat dissipation structure of film capacitor, including the core group for storing electric charge, still include the electric connection spare for electric connection the core group, the core group includes a plurality of parallelly connected core, the electric connection spare is pasted to the electrode side of the core group and forms the heat exchange end, to export the heat in the core group, the electric connection spare is provided with insulating layer on the side away from the core, and the heat exchange end protrudes from the insulating layer to form the initiative heat dissipation arrangement.

[0007] Further, the electric connection spare includes the electrode part for electrically connecting the electrode of the core and the terminal part connected with the electrode part, the electrode part covers the electrode side of the core group, and the side away from the core has the outward protruding protrusion, and the protrusion protrudes from the insulating layer, and the protrusion is the heat exchange end.

[0008] Further, the number of the terminal part is at least two, and includes input terminal part and output terminal part.

[0009] Further, the output terminal part and the electrode part are integrally formed.

[0010] Further, the input terminal part is welded to the electrode part away from the output terminal part.

[0011] Further, the thickness of the output terminal part is 0.9 to 1.1 mm; and / or, the thickness of the electrode part is 0.9 to 1.1 mm; and / or, the thickness of the input terminal part is 3.9 to 4.1 mm.

[0012] Further, the terminal parts are arranged in the insulation layer and fixed to the electrode parts and electrically connected to each other; the electrode part is provided with a welding window for matching the electrode part welded to the electrode of the core.

[0013] Further, the extension direction of at least one terminal part is parallel to the plane where the electrode side of the core group is located.

[0014] Further, the outer layer of the insulation layer is provided with a shell, and the side of the shell facing the heat exchange end has an opening; the electric connector is a copper bar.

[0015] The utility model provides a kind of vehicle-mounted capacitor, at least including the heat dissipation structure of above-mentioned film capacitor.

[0016] The technical scheme provided by the utility model has the following beneficial effects:

[0017] 1. by the heat exchange end of the electric connector and the contact of the heat dissipation waterway of external device, the heat in each core can be exchanged to the cooling medium in the heat dissipation waterway in time, quickly, so it can effectively dissipate heat to each core of film capacitor quickly, in time, to prevent its internal hot spot temperature from being too high, to avoid its capacitance rapid attenuation, while ensuring its service life, therefore, the utility model has good heat management ability, and effectively avoids the occurrence of thermal failure phenomenon.

[0018] 2. the core group includes a plurality of parallelly arranged cores, and the metal film of the core is designed as low square resistance, so as to reduce its equivalent resistance, thereby reducing the heat generated during operation.

[0019] 3. the thickness of the output terminal part and the electrode part of the electric connector is 0.9 to 1.1 mm, and the thickness of the input terminal part of the electric connector is 3.9 to 4.1 mm, so as to reduce the resistance of the electric connector, to ensure that the electric connector has sufficient overcurrent capacity, while effectively reducing the joule heat generated by current through copper bar.

[0020] 4. the extension direction of the input terminal part of the electric connector is parallel to the plane where the electrode side of the core group is located, so as to reduce the overall height of film capacitor, thus facilitating miniaturization design. BRIEF DESCRIPTION OF DRAWINGS

[0021] Fig. 1 The diagram shown is a schematic representation of the heat dissipation structure of the thin-film capacitor in the embodiment.

[0022] Fig. 2 The diagram shown is an exploded view of the heat dissipation structure of the thin-film capacitor in the embodiment.

[0023] Fig. 3 The diagram shown is a schematic of the heat dissipation structure of a thin-film capacitor without an insulating layer in the embodiment. Detailed Implementation

[0024] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention and are mainly used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0025] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0026] Example 1

[0027] Reference Figs. 1 to 3 As shown, Embodiment 1 provides a heat dissipation structure for a thin-film capacitor (hereinafter referred to as the heat dissipation structure) for use in the DC bus capacitor of a new energy vehicle motor controller. It also helps to actively dissipate the heat inside the thin-film capacitor to prevent the internal hot spot temperature from becoming too high.

[0028] The heat dissipation structure of this embodiment includes a core assembly 1 for storing charge and two electrical connectors. Specifically, the core assembly 1 includes multiple cores 11 arranged in parallel, and the metal layer of the core 11 is designed with low sheet resistance, so its equivalent resistance can be reduced, thereby reducing the heat generated during its operation.

[0029] Both electrical connectors are copper busbars with good thermal conductivity, used to electrically connect the positive and negative terminals of each core 11 respectively. Specifically, the electrical connector that simultaneously connects the positive terminals of each core 11 is the positive copper busbar 2, and the electrical connector that simultaneously connects the negative terminals of each core 11 is the negative copper busbar 2'. Of course, in other embodiments, the electrical connectors can also be aluminum alloy electrical connectors, iron alloy electrical connectors, or other metal alloy connectors.

[0030] Both electrical connectors include an electrode portion 23 for electrically connecting the electrodes of the core 11 and two terminal portions for connecting the electrode portions 23. In this embodiment, the two terminal portions of the positive and negative copper busbars are defined as an input terminal portion 21 and an output terminal portion 22, respectively. Of course, in other embodiments, the number of terminal portions of the same electrical connector may be one or more, which will not be described in detail here.

[0031] During assembly, the positive and negative copper busbars are respectively attached to the positive and negative sides of each core 11. The electrode parts 23 of the positive and negative copper busbars sequentially cover the positive and negative ends of each core 11, and each electrode part 23 is welded to the positive and negative ends of each core 11 through the pre-opened welding window 232. This ensures that a reliable electrical connection is formed between them. At the same time, the electrode part 23 of the positive copper busbar 2 sequentially contacts and conducts heat with the positive end of each core 11 to conduct heat out of the core assembly 1.

[0032] Furthermore, the electrode portion 23 of the positive electrode copper busbar 2 is attached to the side where each positive electrode of the core assembly 1 is located and forms a heat exchange end 231 to conduct heat out of the core assembly 1.

[0033] The positive and negative copper busbars are wrapped with an insulating layer 4 on the outside away from the core 11. An outer shell 5 is provided on the outer layer of the insulating layer 4, and the heat exchange end 231 protrudes from the insulating layer 4, thus forming an active heat dissipation device. Of course, the outer shell 5 has an opening on the side facing the heat exchange end 231 to avoid mechanical interference with the heat exchange end 231.

[0034] When the heat exchange end 231 of the positive copper busbar 2 comes into contact with the heat dissipation channel of the external device, the heat in each core 11 can be exchanged to the cooling medium in the heat dissipation channel in a timely and rapid manner, thereby achieving effective heat dissipation, that is, achieving active heat dissipation.

[0035] In this embodiment, the specific insulating layer 4 is an epoxy resin insulating layer formed by a potting process, which wraps the core assembly 1 and the electrode portions 23 of the two electrical connectors, exposing only the heat exchange end 231 and each terminal portion, thus achieving electrical insulation. Of course, the terminals of each electrical connector are respectively inserted through the insulating layer 4 and fixed to the corresponding electrode portion 23, forming an electrical connection with each other.

[0036] By contacting the heat exchange end 231 of the positive copper busbar 2 with the external heat dissipation channel, the heat in each core 11 can be exchanged to the cooling medium in the heat dissipation channel in a timely and rapid manner. This can effectively dissipate heat from each core 11 of the film capacitor in a fast and timely manner, so as to prevent the internal hot spot temperature from becoming too high and thus avoid its capacitance from decaying rapidly, while ensuring its service life. Therefore, the heat dissipation structure of this embodiment has good thermal management capabilities and effectively avoids thermal failure.

[0037] More specifically, the electrode portion 23 of the positive electrode copper busbar 2 has an outward protrusion 231' on the outer side away from the core 11. The protrusion 231' protrudes out of the insulating layer 4, and at this time, the protrusion 231' is the heat exchange end 231.

[0038] In another preferred embodiment, the output terminal portion 22 and the corresponding electrode portion 23 of each electrical connector are processed into copper busbar semi-finished products by an integral molding process. Then, the input terminal portion 21 is welded to the end of the electrode portion 23 of the corresponding copper busbar semi-finished product away from the output terminal portion 22 by a riveting soldering process.

[0039] In practice, the thickness of the output terminal portion 22 and the electrode portion 23 is 0.9 to 1.1 mm, and the thickness of the input terminal portion 21 is 3.9 to 4.1 mm. This reduces the resistance of the copper busbar, ensuring that the copper busbar has sufficient overcurrent capacity, while effectively reducing the Joule heat generated by the current passing through the copper busbar.

[0040] In another preferred embodiment, the extension direction of the input terminal portion 21 of the positive and negative copper busbars is parallel to the plane 12 where the electrode side of the core assembly 1 is located, so as to reduce the overall height of the film capacitor, which is beneficial for miniaturization design.

[0041] Of course, in other embodiments, the positions of the positive copper busbar 2 and the negative copper busbar 2' can be interchanged. Alternatively, the electrode portion 23 of the negative copper busbar 2' can also be provided with a protrusion 231' to form a dual active heat dissipation channel.

[0042] In addition, the connection between each terminal part and the electrode part 23 can also be achieved by welding or screwing, but the heat conduction efficiency will be reduced accordingly.

[0043] Furthermore, the output terminal portion 22 of the positive and negative copper busbars can also be parallel to the plane 12 where the electrode side of the core assembly 1 is located, which can further reduce the overall height of the film capacitor.

[0044] Example 2

[0045] Example 2 provides an on-board capacitor, which includes at least the heat dissipation structure of the thin-film capacitor in Example 1.

[0046] Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims, and all such changes shall be within the scope of protection of the present invention.

Claims

1. A heat dissipation structure for a thin-film capacitor, comprising a core assembly for storing charge, characterized in that: It also includes electrical connectors for electrically connecting the core assembly; The core assembly includes multiple cores arranged in parallel; the electrical connector is attached to the electrode side of the core assembly and forms a heat exchange end to conduct heat out of the core assembly; An insulating layer is provided on the side of the electrical connector away from the core, and the heat exchange end protrudes from the insulating layer to form an active heat dissipation configuration.

2. The heat dissipation structure of the thin-film capacitor according to claim 1, characterized in that: The electrical connector includes an electrode portion for electrically connecting the electrodes of the core and a terminal portion for connecting the electrode portion. The electrode portion covers the electrode side of the core assembly and has an outwardly protruding protrusion on the side opposite to the core. The protrusion protrudes from the insulating layer; the protrusion is the heat exchange end.

3. The heat dissipation structure of the thin-film capacitor according to claim 2, characterized in that: The number of terminal portions is at least two, including an input terminal portion and an output terminal portion.

4. The heat dissipation structure of the thin-film capacitor according to claim 3, characterized in that: The output terminal and the electrode are integrally formed.

5. The heat dissipation structure of the thin-film capacitor according to claim 4, characterized in that: The input terminal is soldered to the end of the electrode portion away from the output terminal portion.

6. The heat dissipation structure of the thin-film capacitor according to claim 4, characterized in that: The thickness of the output terminal portion is 0.9 to 1.1 mm; and / or, the thickness of the electrode portion is 0.9 to 1.1 mm; and / or, the thickness of the input terminal portion is 3.9 to 4.1 mm.

7. The heat dissipation structure of the thin-film capacitor according to any one of claims 2-6, characterized in that: The terminal portion passes through the insulating layer and is fixed to the electrode portion, and is electrically connected to each other; the electrode portion has a welding window for welding the electrode portion to the electrode of the core.

8. The heat dissipation structure of the thin-film capacitor according to any one of claims 2-6, characterized in that: At least one terminal portion extends in a direction parallel to the plane containing the electrode side of the core assembly.

9. The heat dissipation structure of the thin-film capacitor according to any one of claims 1-6, characterized in that: The outer layer of the insulating layer is provided with a shell, and the shell has an opening on the side facing the heat exchange end; the electrical connector is a copper busbar.

10. A vehicle-mounted capacitor, characterized in that: It includes at least the heat dissipation structure of the thin-film capacitor as described in any one of claims 1-9.

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