Integrated electronics kit with direct active capacitor cooling via busbars

Abstract

Integrated electronics kit (1), with: a plurality of capacitors (3) mounted on at least one busbar (2) and fixed along a longitudinal direction of the at least one busbar (2), and a cooling component (4) providing a temperature sink (5), to which the at least one busbar (2) is attached with an electrical insulation layer (6) interposed, wherein the cooling component (4) is designed as a heat exchanger (10) in which cooling fluid guide channels (11) are present, a heat conducting rail (14) is arranged on the at least one current busbar (2), and an additional electrical insulation (12) is arranged between the heat conducting rail (14) and the at least one current collecting rail (2), characterized in that the cooling fluid guide channels (11) run along the longitudinal direction, and the heat conducting rail (14) is directly connected to the cooling component (4).

Description

The present invention relates to an integrated electronic kit having a multiplicity of capacitors mounted on at least one busbar, wherein the busbar is connected to a cooling component which provides a temperature sink, according to the preamble of claim 1.From the motor vehicle field, generic electronic kits are known, such as, for example. Power electronics are already known. In this context, DE 10 2014 215 892 A1 discloses, for example, a cooling cover for the targeted cooling of power output stage modules, a power electronics system with the cooling cover and a hybrid module with an integrated power electronics system.DE 10 2015 225 645 A1, which is not prepublished, discloses a cooling device for cooling power electronics by means of a cooling medium, wherein the cooling device has a cooling housing, an inlet for a cooling medium and an outlet for a cooling medium, wherein the cooling housing has a first fluid channel with a first subregion, a second subregion and a third subregion, and wherein the three subregions of the cooling housing are arranged one behind the other in the flow direction and are connected to one another, and the first subregion has a cross-sectional area which decreases in the course from the inlet to the outlet.Up to now, the cooling of the capacitor has been effected in systems with high power density, in particular in systems with integrated electronics with very high power density, as a rule by the connection of the casting compound or of the housing to a point with low temperature, such as, for example, the housing or a cooling plate. The heat dissipation is conducted over the potting and the housing. This classic cooling connection of the capacitor is only as good as the thermal conductivity of the casting compound or of the housing and thus comes to its limits in systems with high power density, i.e. the heat input on account of the thermal boundary conditions can cause a reduction in the power of the system. The capacitors used must be dimensioned correspondingly larger in order to prevent such a thermal load, as a result of which the installation space must be increased.An integrated electronic kit according to the preamble of claim 1 is known from DE 10 2011 007 315 A1.With regard to further prior art, reference is made to U.S. Pat. No. 2016 / 0 241 155 A1, DE 10 2004 054 060 B3, DE 10 2011 007 307 A1, U.S. Pat. No. 2016 / 0 157 381 A1 and DE 10 2011 077 924 A1.It is the object of the invention to avoid or at least alleviate the disadvantages from the prior art and in particular to provide an electronic kit in which the capacitors can be integrated into a predefined installation space and at the same time to be able to cool the latter in such a way that larger currents can be carried at the same volume without the system being overproved as a result.This object is achieved by the measures specified in claim 1.Advantageous embodiments are claimed in the dependent claims and are explained below.It is provided that a busbar is directly fastened to the cooling component with the interposition of an electrical insulation layer.In this case, it is advantageous if the electrical insulation layer is provided by a foil. A film has only a very small thickness, so that it has virtually no influence on the required installation space. Moreover, a film is flexible and can be easily adapted to the contours of the cooling component.The invention provides that a heat-conducting rail is arranged on the busbar, wherein an additional electrical insulation is provided between the heat-conducting rail and the busbar. Due to this additional insulation, the heat-conducting rails can be mounted directly on the cooler. This enables doubling of the busbars (so-called busbars), whereby a higher thermal capacity is achieved and short-term peak loads can be better absorbed. Thus, a higher integration density is obtained.The heat-conducting rail is advantageously set by an additional rail having at least one attachment extension, wherein the attachment extension is fastened to the cooling component.On the bus bar, a plurality of capacitors are mounted along the longitudinal direction of the bus bar. These can be configured as flat windings, layer windings or as round windings.The cooling component is designed as a heat exchanger. Thus, the insulation is bonded at a location that serves as a heat sink, i.e., where the temperature is relatively low.For this purpose, it is advantageous if the heat exchanger has a contact surface for making contact with the insulation layer and for setting fastening regions for the busbar.In addition, it has proven advantageous if the insulation layer is formed at most half as thick as the thickness of the busbar, and is between 1 μm and 900 μm thick, for example.Cooling fluid conduits are provided in the heat exchanger. These absorb the generated / generated heat of the capacitors and thereby cool the electronics kit.In other words, the cooling is optimized by almost direct connection of the current-carrying rails (power busbars) to the cooling medium. In this case, the condenser is cast in such a way that, after the casting process, the surface pointing outwards is still freely accessible in the direction of the cooling medium.This is completely covered by an electrically insulating film (insulation layer) having a thickness in the μm range. The insulated surface may then be bonded to a radiator. This cooler consists of a material with preferably high thermal conductivity, such as, for example. Aluminum. During operation, the current-carrying rails, which consist of copper, for example, of the capacitor heat up and transfer the heat loss to the cooling unit via the insulation layer which is kept thin. The small thickness of the insulation layer ensures that the heat transfer resistance remains as low as possible. Advantageously, the surface of the heat transfer is designed as large as possible. Moreover, vibrations can be prevented by such an insulation.In other words, the cooling of capacitors in integrated electronic kits is realized by direct dissipation of the heat via so-called hot spots within the capacitors to a heat sink by means of busbars. More specifically, current-conducting bus bars of the capacitors are thermally connected to a heat sink via a thin electrically insulating layer disposed therebetween. An electrical insulation layer is provided on the current-conducting bus bars and a heat-conducting layer of second bus bars is provided on this electrically insulating layer. The thermally conductive layer is (directly) connected to the heat sink.The invention is explained in more detail below with the aid of figures, in which different embodiments are shown. The following are shown: FIG. 1 is a perspective view of an exemplary embodiment of an integrated electronic kit according to the invention; and FIG. 2 shows a first exemplary embodiment of the electronic kit in a perspective view.The figures are merely schematic in nature and serve only to understand the invention. The same elements are provided with the same reference numerals.Features of the individual exemplary embodiments can also be realized in other exemplary embodiments. They are therefore interchangeable.FIG. 1 shows an integrated electronic kit 1 which has busbars 2 and a multiplicity (five here) of capacitors 3, which together can also be referred to as a capacitor package. The busbars 2 are connected to a cooling component 4, which constitutes a temperature sink 5, via an interposed insulation layer 6. For this purpose, fastening regions 7 are provided on the busbars 2 and project outward at an angle from the busbar 2.The capacitors 3 can be designed as round windings, layer windings or as flat windings. Round coils can be wound quickly and firmly with small widths. However, round laps are disadvantageous for assembling many laps in a narrow space. On the other hand, pancakes can simply be stacked to form a package and held together by a steel strip or by insulating paper. However, both capacitor designs are conceivable for the integrated electronic kit disclosed herein.In the exemplary embodiment shown here, the insulation layer 6 is formed as a thin film 8, which is arranged between the busbars 2 and the cooling component 4 on a contact surface 9 of the cooling component 4. In the embodiment shown here, the cooling component 4 is designed as a heat exchanger 10 which has cooling fluid conducting channels 11 (one shown here) running in its longitudinal direction. The cooling fluid flowing through the cooling fluid conducting channels 11 absorbs the heat generated by the capacitors 3 during operation, which is transferred via the busbars 2 and the thin insulation layer 6 to the cooling component 4, transports it further (away from the integrated electronic assembly 1) and thus cools the integrated electronic assembly 1.The insulation layer 6, which is formed as a foil 8, provides a large surface for the heat transfer from the capacitors 3 via the busbars 2 to the cooling body 4 and, due to its only very small thickness, which is located in the μm range, represents only a very low heat transfer resistance.The busbars 2 preferably consist of a material with very good electrical conductivity, such as, for example. Copper. The heat of the capacitors 3 generated during operation is dissipated to the cooling component 4 via its busbars 2 and the insulation layer 6, which is embodied as a foil 8. The cooling component 4 is preferably made of a material with a high thermal conductivity, such as, for example. Aluminum.FIG. 2 shows a perspective view of a first exemplary embodiment of the integrated electronic kit 1. an additional insulation 12 is also applied / provided on the busbars 2 in addition to the insulation layer 6 between the contact surface 9 of the cooling component 4 and the busbars 2. This additional insulation 12 is in turn followed by a second layer of current busbars which are designed as an additional rail 13 in the form of a heat-conducting rail 14.The heat-conducting rails 14 are electrically insulated from the busbars 2 via the additional insulation 12, for which reason they can be connected directly to the cooler 4 via connection extensions 15. The busbars 2 are connected to or fastened to the cooling component 4 via the fastening regions 7 with the interposition of the insulation layer 6, as is also the case in the first exemplary embodiment (see FIG. 1 ).Such an arrangement enables doubling of the installed busbars 2, 14, whereby a higher thermal capacitance is achieved than in the variant of the integrated electronic kit 1 explained as a non-inventive exemplary embodiment.This first exemplary embodiment has the advantage that a higher thermal capacity can be achieved by doubling the busbars (the busbars 2 and the heat-conducting rail 14) and short-term peak loads can be better absorbed. As a result, the integration density can be increased.List of reference characters1 Electronics kit 2 Busbar 3 Capacitor 4 Cooling component 5 Temperature sink 6 Insulation layer 7 Fastening device 8 Foil 9 Contact surface 10 Heat exchanger 11 Cooling fluid conducting channel 12 Additional insulation 13 Additional rail 14 Heat conducting rail 15 Connecting extension 16 Fastening region

Claims

Integrated electronic kit (1), having: a multiplicity of capacitors (3) which are applied to at least one busbar (2) and are fastened along a longitudinal direction of the at least one busbar (2), and a cooling component (4) which provides a temperature sink (5) and to which the at least one busbar (2) is fastened with the interposition of an electrical insulation layer (6), wherein the cooling component (4) is designed as a heat exchanger (10) in which cooling fluid conducting channels (11) are present, a heat conducting rail (14) is arranged on the at least one busbar (2), and an electrical additional insulation (12) is arranged between the heat conducting rail (14) and the at least one busbar (2), characterized in that the cooling fluid conducting channels (11) run along the longitudinal direction, and the heat conducting rail (14) is connected directly to the cooling component (4).Integrated electronic kit (1) according to claim 1, characterized in that the electrical insulation layer (6) is a foil (8).Integrated electronic kit (1) according to claim 1 or 2, characterised in that the heat-conducting rail (14) is set by an additional rail (13) with at least one attachment extension (15) fastened to the cooling component (4).Integrated electronic kit (1) according to one of Claims 1 to 3, characterized in that the heat exchanger (10) has a contact surface (9) for making contact with the insulation layer (6) and for setting fastening regions (16) for the at least one busbar (2).Integrated electronic kit (1) according to one of Claims 1 to 4, characterized in that the insulation layer (6) is formed at most half as thick as the thickness of the at least one busbar (2).Integrated electronic kit (1) according to one of claims 1 to 5, characterised in that the insulation layer (6) is between 1 μm and 900 μm thick.

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