Insulation mat for the power electronics of a motor vehicle

Abstract

The invention relates to an insulation mat for the power electronics of a motor vehicle, comprising at least the following components: - an electrically and thermally insulating carrier film; and - Electrically insulating and thermally conductive filler material. The insulating mat is characterized in particular by the fact that the carrier film has a perforated retaining section and a closed edge section; wherein the perforated retaining section is arranged in the filler material and thus the carrier film is connected to the filler material, and The openings of the perforation of the retaining section are filled with the filler material, so that the thermal conductivity through the retaining section is increased. where the closed edge section protrudes from the filling material at least in sections. An insulating mat with a perforated carrier film is proposed, which increases the thermal conductivity.

Description

[0001] The invention relates to an insulating mat for power electronics of a motor vehicle, a pre-assembly unit with such an insulating mat for power electronics of a motor vehicle, power electronics with such a pre-assembly unit for a motor vehicle, and a manufacturing method for such power electronics.

[0002] Power electronics for battery-electric or hybrid vehicles are known from industrial practice, enabling the control of the vehicle's high-voltage electrical system. Such power electronics include, for example, a battery junction box and a current control unit. The battery junction box contains components such as fuses, contactors, and busbars or conductors to the individual components of the high-voltage system. The current control unit includes components such as power converters, for example, AC-DC converters or DC-DC converters.

[0003] The electrical power losses of both the battery junction box components and the power control unit components must be dissipated by means of cooling. Solutions are known from industrial practice where a common cooling plate, which is integrated into the power control unit, is used for both the power control unit and the battery junction box. The high-voltage components of the battery junction box that require cooling are thermally coupled to the cooling plate by means of a thermally conductive filler material, also known as a gap pad or gap filler. The filler material is, for example, bonded to the cooling plate using a carrier film.

[0004] A disadvantage is that the carrier film has a thermally insulating effect and thus reduces the cooling performance of the cooling plate for the high-voltage component of the battery junction box.

[0005] DE 10 2021 003 748 A1 discloses an arrangement for cooling a high-voltage component, comprising a high-voltage component arranged on a circuit carrier and coupled to a heat sink, wherein a gap filler material and an insulating layer are arranged between the high-voltage component and the heat sink, the insulating layer being covered on both sides with a gap filler material.

[0006] DE 10 2023 200 062 A1 discloses a busbar arrangement for cooling a busbar. The busbar arrangement comprises a busbar, a first thermal conductivity material, a second thermal conductivity material, an insulating film, a cooling medium, and a housing, wherein the busbar has a top surface and a bottom surface opposite the top surface, as well as a longitudinal extension in a first horizontal direction and a transverse extension in a second horizontal direction, which is oriented orthogonally to the first horizontal direction, and wherein the bottom surface of the busbar is connected to the first thermal conductivity material over a surface, wherein the first thermal conductivity material is connected to the insulating film over a surface at one bottom surface, and a bottom surface of the insulating film is connected to the second thermal conductivity material.wherein a bottom side of the second thermal conductivity material is arranged on the cooling medium and wherein the insulating film protrudes on both sides in the second horizontal direction relative to the first thermal conductivity material and the second thermal conductivity material, the protrusion being bonded to the housing in each case.

[0007] Based on this, the present invention aims to overcome, at least partially, the disadvantages known from the prior art. The features of the invention are defined in the independent claims, for which advantageous embodiments are shown in the dependent claims. The features of the claims can be combined in any technically meaningful way, whereby the explanations in the following description and features from the figures, which comprise supplementary embodiments of the invention, can also be used.

[0008] The invention relates to an insulation mat for the power electronics of a motor vehicle, comprising at least the following components: - an electrically and thermally insulating carrier film; and - Electrically insulating and thermally conductive filling material.

[0009] The insulation mat is characterized primarily by the fact that the carrier film has a perforated retaining section and a closed edge section; wherein the perforated retaining section is arranged in the filling material and thus the carrier film is connected to the filling material, and The openings of the perforation of the retaining section are filled with the filler material, so that the thermal conductivity through the retaining section is increased. where the closed edge section protrudes from the filling material at least in sections.

[0010] Unless explicitly stated otherwise, ordinal numbers used in the preceding and following descriptions serve solely for unambiguous differentiation and do not indicate any order or ranking of the components referred to. An ordinal number greater than one does not necessarily imply the presence of another such component.

[0011] An insulating mat for the power electronics of a motor vehicle, preferably an electric or hybrid vehicle, is proposed here. The power electronics are designed to regulate the vehicle's high-voltage electrical system.

[0012] The insulation mat has an electrically and thermally insulating carrier film and an electrically insulating and thermally conductive filling material.

[0013] The insulation mat has a principal plane extending transversely, preferably orthogonally, to an insulation direction. Preferably, the thickness of the insulation mat along the insulation direction is greater, preferably many times greater, than the width and length of the insulation mat arranged in the principal plane.

[0014] The carrier film is electrically and thermally insulating. Electrically insulating in this context means that the material has a high electrical resistance, high dielectric strength, and / or low electrical conductivity. The electrical resistance is preferably at least one megaohm, and particularly preferably at least ten megaohms. The electrical conductivity is preferably a maximum of 10 -10 S / m [Siemens per meter], particularly preferably a maximum of 10 -12 S / m [Siemens per meter]. Preferably, the dielectric strength is at least 10 kV / mm [ten kilovolts per millimeter].

[0015] Preferably, the carrier film comprises a plastic. For example, the carrier film comprises at least one of the materials from the following list: - Polyimide (PI); - Polyethylene (PE); - Polyethylene naphthalate (PEN); - Polyethylene terephthalate (PET); - Polyvinyl chloride (PVC); - Polypropylene (PP); and - Fluoropolymers (e.g. PTFE, FEP).

[0016] The carrier film holds the filling material, also known as gap pad or gap filler. Preferably, the carrier film is designed to simplify handling of the insulation mat, for example, during installation. For this purpose, the carrier film may have, for example, protruding handling tabs in its main plane. The carrier film may also be designed to mechanically stabilize the insulation mat. Furthermore, the carrier film may be designed to provide an installation guide or to attach the mat to the current-carrying component and / or the heat sink.

[0017] The electrically insulating and thermally conductive filler material, also known as a gap pad or gap filler, is designed to provide a thermal interface and electrical insulation between a current-carrying component and a heat sink. The insulating mat is positioned along the insulation direction between the heat sink and the current-carrying component. The gap pad or gap filler is designed to maximize thermal conductivity between heat-generating, current-carrying components and heat sinks to ensure efficient heat dissipation, while simultaneously providing electrical insulation to prevent short circuits and electrical breakdowns.

[0018] The filling material exhibits high electrical insulating properties to prevent unwanted current flow, such as electrical short circuits and / or breakdowns. This is achieved through high dielectric strength and / or high electrical resistance, as defined above.

[0019] The filler material is thermally conductive to transfer heat from the heat-generating, current-carrying component, such as a high-voltage component (e.g., a busbar in the battery junction box), to a heat sink (e.g., a cooling plate). For example, the filler material has a thermal conductivity in the range of one to ten W / mK (watts per meter and Kelvin).

[0020] For example, the filler material is designed to conform to the surfaces of the components to be coupled in order to ensure efficient thermal coupling. To this end, the filler material has, for example, a soft and compressible structure that allows it to bridge unevenness and surface roughness. Preferably, the filler material is also elastic, so that, for example, deformations and aging effects of the battery cells during operation can be compensated for. Alternatively or additionally, the filler material is, for example, adapted to the surface during application and then hardens. Preferably, the filler material hardens elastically, so that it remains elastic even after hardening, as described above.

[0021] For example, the filling material contains at least one of the materials from the following list: - Silicone; - Ceramic particles, which are embedded, for example, in a matrix of the filler material, for example, made of aluminum oxide [Al2O3] and / or boron nitride [BN]; and - Plastics and polymers, for example as matrix material.

[0022] The carrier film has a perforated retention section and a closed edge section. Perforated means that the carrier film has multiple openings extending along the insulation direction. Preferably, the openings occupy a larger area (in the main plane of extension) of the perforated retention section than the remaining material webs of the carrier film in this area, thus significantly reducing the thermal insulation effect of the carrier film. For example, at least two-thirds of the area of ​​the perforated retention section is formed by openings, and at most one-third by the remaining material webs.

[0023] Closed means that a corresponding edge section around the holding section has no openings that would significantly reduce the electrical insulation effect in the edge sections.

[0024] The perforated holding section is positioned within the filler material. Thus, the carrier film is bonded to the filler material, or rather, the filler material and carrier film are attached to each other. For example, the carrier film is pressed into the still-cured filler material and / or the filler material is sprayed onto the carrier film.

[0025] Accordingly, the openings of the perforation in the retaining section are filled with the filler material. Thus, the filler material is only interrupted by the remaining material ridges. Consequently, uninterrupted thermal coupling between the current-carrying component and the heat sink is ensured in the area of ​​the openings by means of the filler material.

[0026] The closed edge section protrudes beyond the filler material. In other words, the closed edge section extends outside the perforated retaining section in the main plane of extension. Thus, the edge section forms a section outside the filler material that is not perforated and therefore provides high electrical insulation.

[0027] The edge section thus increases the creepage distance, preventing current flow around the filler material. Preferably, the edge section extends completely around the filler material.

[0028] Preferably, the insulation mat comprises a plurality of filling materials on a common carrier film. Preferably, the plurality of filling materials are arranged separately from one another in the main plane of extension.

[0029] The filler material adds weight and space. Furthermore, thermal coupling between the current-carrying components and the heat sink is desirable, but thermal coupling with other adjacent components should be avoided. Therefore, it is advantageous to use the filler material sparingly to prevent unwanted thermal coupling and save weight and space.

[0030] The proposed insulation mat allows for the economical use of filling material, only in an area necessary for thermal coupling, while still providing high thermal coupling and good electrical insulation.

[0031] Furthermore, the insulation mat is particularly easy to install using the carrier film.

[0032] In a further advantageous embodiment of the insulation mats, it is proposed that the insulation mat be designed as a prefabricated component that can be assembled.

[0033] According to this embodiment, the insulation mat is designed as a pre-assembled component. In other words, the insulation mat can be mounted as a complete unit between the current-carrying component and the heat sink, for example by gluing and / or welding.

[0034] In a further advantageous embodiment of the insulation mats, it is proposed that the filling material on both sides of the carrier film has a predefined thickness.

[0035] According to this embodiment, the carrier film is arranged in the filler material such that the filler material is positioned on both sides of the carrier film along the insulation direction. For example, the carrier film is arranged centrally within the filler material along the insulation direction.

[0036] According to another aspect, a pre-assembly unit for the power electronics of a motor vehicle is proposed, comprising at least the following components: - a current-carrying component; and - an insulating mat attached to the current-carrying component according to an embodiment as described above.

[0037] Here is a proposed pre-assembly unit for power electronics for a motor vehicle.

[0038] The pre-assembly unit includes a current-carrying component and an insulating mat as described above.

[0039] The current-carrying component generates power loss during operation, which must be dissipated in the form of heat. Furthermore, the current-carrying component must be electrically insulated from other components.

[0040] For example, the current-carrying component is a component of a battery junction box, such as a busbar.

[0041] The insulation mat is pre-mounted on the live component. For example, the insulation mat is glued to the live component.

[0042] The aspect proposed here allows for particularly easy assembly.

[0043] Preferably, the filling material of the insulation mat does not extend beyond the current-carrying component in the main plane. In other words, the filling material in the main plane is smaller than or the same size as the current-carrying component and therefore does not extend beyond the edges that define the current-carrying component along the main plane. This ensures particularly easy transportability of the pre-assembled unit.

[0044] According to another aspect, a power electronics system for a motor vehicle is proposed, comprising at least the following components: - an insulation mat according to an embodiment as described above; - a current-carrying component; and - a heat sink; the filling material of the insulation mat is positioned between the current-carrying component and the heat sink.

[0045] A power electronics system for a motor vehicle is proposed here. The power electronics system includes at least an insulating mat, a current-carrying component, and a heat sink.

[0046] For example, such power electronics include a battery junction box and a power control unit. The battery junction box, for example, includes fuses, contactors, and busbars or conductors to the individual components of the high-voltage network. The power control unit, for example, includes a power converter, such as an AC-DC converter or a DC-DC converter.

[0047] In this process, the electrical power losses of both the current-carrying component of the battery junction box, such as the busbars, and the current-carrying components of the power control unit, such as the power converters, must be dissipated by means of cooling. A common heat sink is used for this purpose. For example, the current-carrying component of the battery junction box is thermally coupled to the heat sink by means of the insulating mat's filler material, also known as a gap pad.

[0048] The insulation mat is manufactured according to the preceding description. For example, the insulation mat is manufactured as a pre-assembled unit together with the current-carrying component, according to the preceding description.

[0049] The current-carrying component is a component that requires cooling. In other words, the current-carrying component generates power loss during operation, which must be dissipated in the form of heat. Therefore, the current-carrying component must be electrically insulated from other components.

[0050] For example, the current-carrying component is a component of the battery junction box, such as a busbar.

[0051] The heat sink is, for example, a cooling plate. Preferably, the heat sink is permeable to a cooling medium, for example, a dielectric or a water-based cooling medium. Preferably, such a cooling plate is arranged parallel to the main plane of extension.

[0052] The filling material is arranged along the insulation direction between the current-carrying component and the heat sink, thus bridging a gap between the current-carrying component and the heat sink to ensure good heat transfer.

[0053] Preferably, the filling material (in the main plane of extension) is arranged, particularly preferably completely, in an overlap region between the heat sink and the current-carrying component. For example, the overlap region is completely or only partially (along the main plane of extension) filled with the filling material.

[0054] For example, the remaining area of ​​overlap (along the main extension plane) is covered by the closed boundary section.

[0055] The overlap area refers to the area in which the current-carrying component and the heat sink overlap in the main extension plane.

[0056] Preferably, the closed edge section of the carrier film extends beyond the overlap area of ​​the heat sink and the current-carrying component. Preferably, the closed edge section extends beyond the overlap area (in the main plane of extension) at least to such an extent that current flow between the current-carrying component and the heat sink is prevented due to the extended creepage distance.

[0057] Preferably, the heat sink is larger than the current-carrying component in its main plane of extension. In such an embodiment, the filler material in the main plane of extension is, for example, flush with the current-carrying component, i.e., completely covering it, or smaller than it, i.e., covering only a portion of the current-carrying component. Preferably, the carrier film or the edge region of the carrier film is designed to extend beyond the current-carrying component to such an extent that the creepage distance prevents unwanted current flow.

[0058] In an advantageous embodiment of the power electronics, it is further proposed that the current-carrying component is a component of a battery junction box, preferably a busbar.

[0059] In a further advantageous embodiment of the power electronics, it is proposed that the heat sink is integrated into a current control device on the side facing the current-carrying component.

[0060] For example, the current control device has a control housing. For example, the heat sink, preferably a cooling plate, is integrated into the current control device, preferably into the control housing. The heat sink is arranged on the side of the current control device facing the current-carrying component or battery junction box.

[0061] For example, the battery junction box has a box housing. Alternatively or additionally, the battery junction box and the current control unit are integrated into a common power electronics housing.

[0062] According to another aspect, a manufacturing process for power electronics according to an embodiment of the above description is proposed, comprising the following steps: a. Providing the insulation mat; b. Attaching the insulation mat to the current-carrying component or the heat sink; and c. Pressing the respective opposite side of the insulation mat, of the current-carrying component and the heat sink, against the fastening from step b.

[0063] Here is a proposed manufacturing process for power electronics of a motor vehicle, which includes at least the steps a., b. and c. explained in more detail below in the order given.

[0064] In step a., the insulation mat is provided as a pre-assembled, ready-to-install component. The insulation mat comprises the carrier film and the filling material, which are bonded together.

[0065] In step b., the insulation mat is attached either to the current-carrying component or to the heat sink, for example by gluing.

[0066] In step c, the side opposite the insulation direction, i.e., the side facing away from the attachment in step b, is then pressed against the other component. Thus, if the insulation mat was attached to the current-carrying component in step b, it is now pressed against the heat sink with the side facing away from the current-carrying component along the insulation direction and preferably attached to it.

[0067] The invention described above is explained in detail below against the relevant technical background with reference to the accompanying drawings, which show preferred embodiments. The invention is in no way limited by the purely schematic drawings, although it should be noted that the drawings are not dimensionally accurate and are not suitable for defining size relationships. It is illustrated in Fig. 1: Power electronics with an insulating mat; Fig. 2: an insulation mat for power electronics according to Fig. 1 in a schematic sectional view; and Fig. 3: a pre-assembly unit for power electronics according to Fig. 1 in a top view.

[0068] In Fig. Figure 1 shows a power electronics unit 2 with an insulating mat 1 in a sectional view. The power electronics unit 2 is part of a motor vehicle's high-voltage network and is designed to regulate the high-voltage network. For this purpose, the power electronics unit 2 includes a battery junction box 11 and a current control unit 13.

[0069] The Battery Junction Box 11 comprises fuses, contactors, and busbars 12 or conductors to the individual high-voltage components of the high-voltage network. The Battery Junction Box 11 thus includes a number of current-carrying components 9 of the high-voltage network, which must be cooled during operation due to the power losses during current flow.

[0070] The power control unit 13 includes, among other things, power converters, here an AC-DC converter and a DC-DC converter, and a heat sink 10, here designed as a cooling plate. A cooling medium can flow through the cooling plate to provide cooling. Thus, for example, the heat-generating components of the power control unit 13, such as the power converters, can be cooled. The heat sink 10 is arranged along an insulation direction 15 on one side facing the battery junction box 11.

[0071] Along the insulation direction 15, the insulation mat 1 is arranged between the battery junction box 11 and the current control device 13 or the heat sink 10.

[0072] Battery Junction Box 11 is also thermally connected to the heat sink 10 by means of the insulation mat 1 and can therefore be cooled by means of the heat sink 10. For example, individual current-carrying components 9 of the Battery Junction Box 11, such as the busbars 12, which have a high cooling requirement, are insulated by means of a filler material 4 (not shown here, see Figure 1). Fig. 2) the insulation mat 1 is thermally coupled to the heat sink 10.

[0073] The insulation mat 1 electrically insulates the current-carrying components 9 of the battery junction box 11 from the heat sink 10 or the current control unit 13.

[0074] Both the heat sink 10 and the insulation mat 1 are arranged parallel to a main extension plane, which is arranged orthogonally to the insulation direction 15.

[0075] In Fig. Figure 2 shows a schematic sectional view of an insulation mat 1. As shown on the right, a heat sink 10, in the form of a cooling plate, is indicated. A dielectric fluid or cooling water can flow through the heat sink 10 to dissipate the waste heat from a current-carrying component 9, for example, a busbar 12.

[0076] The insulation mat 1 is arranged between the heat sink 10 and the current-carrying component 9. The insulation mat 1 comprises a carrier film 3 and the filler material 4. The carrier film 3 includes a perforated retaining section 5 and a closed edge section 6.

[0077] The filling material 4 is designed for thermal connection and electrical insulation between the heat sink 10 and the current-carrying component 9.

[0078] The perforated retaining section 5 has openings 7 through which the filling material 4 extends. As shown, the filling material 4 is arranged along the insulation direction 15 on both sides of the retaining section 5 with approximately the same thickness.

[0079] The carrier film 3 is attached to the filling material 4 by means of the retaining section 5 by means of material webs 14 which surround the openings 7.

[0080] The edge sections 6 of the carrier film 3 are not perforated, i.e., closed. Therefore, they provide high electrical insulation.

[0081] In Fig. 3 is a pre-assembly unit 8 for a power electronics 2 according to Fig. 1 in a top view. The pre-assembly unit 8 comprises a battery junction box 11 with a plurality of busbars 12 as current-carrying components 9. Filler material 4 is arranged section by section on the busbars 12 to conduct the heat from the power loss of the busbars 12 to the heat sink 10.

[0082] The filling material 4 is, as in relation to Fig. 2 explained, supported by a carrier film 3 which has perforated retaining sections 5 in the area of ​​the filler material 4 in order to increase the thermal conductivity in these areas. In the closed edge section 6, which surrounds the retaining sections 5 or which is arranged between the retaining sections 5, good electrical insulation is thus ensured, so that sufficiently high creepage distances are provided.

[0083] For example, the majority of the filling materials 4 are held in place by a carrier film 3. This makes it possible, as shown here, to mount the majority of the filling material elements, such as gap pads or gap fillers, simultaneously in the desired positions. Thus, for example, the pre-assembly unit 8 shown can be manufactured.

[0084] An insulating mat with a perforated carrier film is proposed, which increases the thermal conductivity. Reference symbol list 1 insulation mat 2 Power Electronics 3 carrier film 4 Filling material 5 perforated holding section 6 closed edge section 7 Opening 8 Pre-assembly unit 9 current-carrying components 10 heat sinks 11 Battery Junction Box 12 busbar 13 Power control device 14 material walkways 15 Insulation direction

Claims

[1] Insulation mat (1) for power electronics (2) of a motor vehicle, comprising at least the following components: - an electrically and thermally insulating carrier film (3); and - electrically insulating and thermally conductive filling material (4), characterized by , that the carrier film (3) has a perforated holding section (5) and a closed edge section (6); wherein the perforated retaining section (5) is arranged in the filling material (4) and thus the carrier film (3) is connected to the filling material (4), and openings (7) of the perforation of the retaining section (5) are filled by the filling material (4) so ​​that the thermal conductivity through the retaining section (5) is increased, wherein the closed edge section (6) protrudes at least partially from the filling material (4). [2] Insulation mat (1) according to claim 1, wherein the insulation mat (1) is designed as a mountable prefabricated component. [3] Insulation mat (1) according to claim 1 or claim 2, wherein the filling material (4) has a predefined thickness on both sides of the carrier film (3). [4] Pre-assembly unit (8) for power electronics (2) of a motor vehicle, comprising at least the following components: - a current-carrying component (9); and - an insulating mat (1) attached to the current-carrying component (9) according to any one of claims 1 to 3. [5] Power electronics (2) for a motor vehicle, comprising at least the following components: - an insulation mat (1) according to any one of claims 1 to 3; - a current-carrying component (9); and - a heat sink (10); wherein the filling material (4) of the insulation mat (1) is arranged between the current-carrying component (9) and the heat sink (10). [6] Power electronics (2) according to claim 5, wherein the current-carrying component (9) is a component of a battery junction box (11). [7] Power electronics (2) according to claim 5 or claim 6, wherein the heat sink (10) is integrated in a current control device (13) on a side facing the current-carrying component (9). [8] Manufacturing method for a power electronics (2) according to any one of claims 2 to 7, comprising the following steps: a. Providing the insulation mat (1); b. Attaching the insulation mat (1) to the current-carrying component (9) or the heat sink (10); and c. Pressing the respective other of the current-carrying component (9) and heat sink (10) against the side of the insulation mat (1) opposite the fastening from step b.

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