Electronics cooler, electronics device with an electronics cooler

Abstract

Disclosed is an electronics cooler (KL) for cooling an electronic device (EV), comprising: - a cooling channel for passing a liquid coolant; - a cooler part which at least partially encloses the cooling channel; - an integrally formed coolant-permeable sponge-like insert body made of a thermally conductive material, which is arranged in the cooling channel and is held non-movably in the cooling channel by the cooler part. Furthermore, an electronic device (EV) with a said cooler (KL) and an inverter with a said electronic device (EV) are described.

Description

Technical Field:The present invention relates to a (power) electronics cooler or a cooler for cooling a (power) electronics device, for example a (power) MHDC converter or a (power) radiator, in particular an electrically driven vehicle. The invention further relates to a (power) electronic device having a said cooler and to a (power) inverter having a said (power) electronic device.STATE OF THE ART AND OBJECT OF THE INVENTIONElectronics coolers for cooling an electronics device are known and are used, inter alia, in (power) DCDC converters or (power) inverters, for example of electrically driven vehicles, for cooling the electronics devices or power modules (having a plurality of power semiconductor switches or comparable circuit components with high power losses) of the DCDC converters or the inverters.Such coolers are used, for example, in inverters of various electric cars for cooling the inverters or their power modules (having a plurality of power semiconductor switches).The publication EP 1 225 633 A1 describes a cooler having a cooling channel for cooling a power semiconductor module, which has a porous ceramic foam body, through which a cooling liquid flowing through the cooling channel can flow in the cooling channel and which is in thermal contact with the module to be cooled in a planar manner via a cooling surface of the cooler. Furthermore, the document describes a structure comprising a cooler and a power semiconductor module which rests on the cooler and is cooled by the latter.U.S. Pat. No. 6,037,658 A describes an electrical structure which has a heat-generating power module and a cooling body with a cooling duct for cooling the module. The assembly further includes a woven porous wire member disposed in the cooling channel.The publication DE 10 2004 021 810 A1 describes a structure made of an electronic component, a metallic cooling body and an electrically insulating substrate, wherein the substrate is connected to the cooling body via a cohesive connection, wherein the connection comprises a thin layer of solder material and a body made of metal foam or metal felt.The publication DE 10 2021 131 736 A1 describes a high-power converter having a cooling arrangement for cooling power cells of the converter. The cooling arrangement has a cooling channel for passing a cooling medium through it, in which sheet metal ribs are formed for better heat transfer.With the ever-increasing power requirement for the above-mentioned electronic devices, the requirement for efficient cooling of these electronic devices also increases. In particular in the electronic devices with high-power semiconductors, such as silicon carbide (SiC) or gallium nitride (GaN) semiconductors, the requirement for efficient cooling is particularly high.The object of the present application is thus to provide a possibility with which an electronic device, for example an inverter or a DCDC converter, can be cooled efficiently.DESCRIPTION OF THE INVENTIONThis object is achieved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.According to a first aspect of the invention, an electronics cooler or a cooler for cooling a (power) electronics device, for example a power DCDC converter or a power inverter, in particular an electrically driven vehicle, is provided.The cooler has a cooling duct for passing a liquid coolant, such as cooling water, for example, and a cooler part which at least partially surrounds the cooling duct (in its periphery). Furthermore, the cooler has a coolant-permeable (or open-pored) sponge-like insert body formed in one piece and made of a thermally conductive material, which is arranged in the cooling duct and is in thermal contact with the cooler part (or with the duct wall of the cooling duct) and is held in a non-movable manner by the cooler part in the cooling duct. The cooler part has a surface facing the cooling channel, which is roughened for surface enlargement. The roughened surface, due to its rough structure, holds the insert body in the cooling channel in a non-movable manner in a frictional manner to the predetermined position.The cooler part forms part of a duct wall of the cooling duct and, during operation of the electronic device, conducts the waste heat from the latter to the coolant flowing through the duct. The cooler part can be a cooler ceiling, on the surface of which facing away from the cooling channel the electronics device to be cooled or part thereof can be arranged and thermally connected to the latter. In this case, the cooler part also has the function of a circuit carrier or can also be embodied as a circuit carrier with corresponding circuit structures such as, for example, conductor tracks.The insert body is a three-dimensional mesh spongy (similar to a bath sponge) structureless structure made of a plurality of (fine) threads (or wires) of a thermally conductive material, with many cavities surrounded only partially by these threads for conducting the coolant. The threads are connected to one another in a structureless manner in such a way that the structure does not have a grid-like or other comparable structure. In particular, the threads (apart from manufacturing tolerances) have a diameter of between 1 millimeter and 50 micrometers.Because the insert body is arranged in the cooling channel and is in thermal contact with the cooler part (or with the channel wall of the cooling channel), the insert body can absorb the waste heat during cooler operation directly from the cooler part (or from the channel wall) via the thermal contact with the cooler part (or with the channel wall of the cooling channel) and transfer it to the coolant flowing through the cooling channel. The structure of the insert body from the plurality of thermally conductive threads receives the waste heat from the cooler part (or from the channel wall of the cooling channel) and passes it on to the coolant which flows through the cavities bordered by these threads. As a result, the thermal deposit from the cooler part or from the duct wall of the cooling duct to the coolant is shortened.The plurality of filaments and the plurality of cavities surrounded only partially by these filaments increase the heat transfer surface in the cooling duct, around which the coolant can flow directly. In addition, the filaments in the cooling channel form numerous (micro)flow bodies with small geometrical dimensions, which generate numerous local (micro)flows or (micro)flows in the coolant flowing through the cavities between the filaments. Because the filaments have small diameters, the pressure drop across the individual filaments remains negligibly small in comparison with conventional cooler pins or other known cooler pin fin structures having a comparatively few number of flow bodies having a comparatively larger diameter. Local flow speeds in the inter-filament cavities are even increased thanks to the local restrictions between the filaments, which in addition makes the local (micro) heat transfer efficiency from the filaments to the coolant flowing through the cavities noticeably increase due to the local (micro) heat transfer efficiencies.This provides a possibility with which an electronic device, for example an inverter or a DCDC converter, can be cooled efficiently.The insert body has in particular sufficient mechanical rigidity so that it remains at the predetermined position in the cooling channel during cooler operation of the cooler and despite the pressure of the coolant flowing through the cooling channel and additionally retains its coolant-permeable (or open-pored) sponge-like shape.The insert body can be (elastically) compressible, wherein the cooler part can be held fixed in the cooling channel in a non-movable manner under the action of a compressive force on the insert body. In this case, the insert body is compressed only slightly, for example, by less than 10% or less than 5% or even less than 2%, of its original overall height. As a result, the insert body continues to remain coolant-permeable or open-pored. Accordingly, the hollow spaces between the threads of the structure of the insert body remain largely present and can continue to allow the coolant to pass through.In this case, the insert body has a mechanical rigidity which is sufficient for the insert body to remain at the predetermined position in the cooling duct during the cooler operation of the cooler and to retain its shape, but which (rigidity) is not sufficient to withstand the compressive force acting from the cooler part on the insert body during the assembly, with the result that the insert body can still be (elastically) compressed under the action of the compressive force and can therefore be held in a non-movable manner in the cooling duct by the cooler part.The insert body can be a three-dimensional knit of wires or threads made of a metal, a graphite-based material, or of copper or a copper alloy, which is formed in particular in an unstructured or structurallyless manner.The expression "unstructured or structurally free" means here that the insert body does not have a structured geometry, similar to a grid structure, which repeats, in particular continuously over the entire insert body. Rather, the expression means that the insert body does not have a defined topology or a uniform cell geometry. The insert body can have, for example, an uneven or irregular grid cell geometry. In particular, the insert body does not have a "long range order, similar to an amorphous solid.".The insert body can also be a three-dimensional nonwoven made of a metal, a graphite-based material, or made of copper or a copper alloy, which is formed in particular in an unstructured or structurallyless manner.The insert body can also be a three-dimensional foam body made of a metal or a graphite-based material or copper or a copper alloy, which is formed in particular in an unstructured or structurallyless manner.The insert body can, however, also be a three-dimensional foam body made of a metal or a graphite-based material or copper or a copper alloy, which is formed in particular in an unstructured or structurallyless manner.The insert body can, however, also be a three-dimensional wool-shaped body made of a metal or a graphite-based material or copper or a copper alloy, which is formed in particular in an unstructured or structurallyless manner. The insert body can also be a three-dimensional mesh-like body made of a metal or a graphite-based material or copper or a copper alloy, which is formed in particular in an unstructured or structurallyless manner.The cooler part can non-movably hold the insert body in the cooling channel in a positive-locking or non-positive-locking manner or in a materially integral manner.In this case, the surface of the cooler part facing the cooling channel can be roughened by means of an ablative production method, such as by laser machining, in particular by direct laser interference patterning (DLIP), or by erosion or sandblasting. Alternatively, the surface may be roughened by an application (additive) manufacturing method such as fine powder coating (FPC), sputtering, or cold gas coating.The cooler part may be manufactured by 3D printing. In this case, the surface of the cooler part facing the cooling channel can also be directly co-shaped in a 3D printing process with a defined increased surface roughness.Roughening the surface increases the surface area of the radiator part facing the cooling channel, thereby improving heat transfer from the radiator part to the coolant flowing through the channel via the increased surface area. In addition, the roughened surface generates (microscal) vortices - turbulent flows, in particular turbulent boundary layer flows - and thus additionally increases the cooling efficiency.The cooler part can have on the surface facing the cooling channel at least one projection which projects into the cooling channel in a pin-shaped manner and which holds the insert body in the cooling channel in a non-movable manner (similar to a form-fit connection).The cooler part can have both the roughened surface and the at least one protrusion, or only the roughened surface or only the at least one protrusion for holding the insert body. In this case, the roughened surface and / or the at least one protrusion prevent the insert body or part thereof from slipping or displacing in the cooling duct and thus compacting the insert body by slipping part of the insert body. Accordingly, the roughened surface and / or the at least one protrusion ensure that the insert body remains at the predetermined position in the cooling channel even during cooler operation of the cooler and despite the pressure of the coolant flowing through the cooling channel and additionally retains its coolant-permeable (or open-pored) sponge-like shape.Accordingly, the roughened surface does not produce a conventional form-fitting connection which is generally known in connection technology, but rather holds the insert body at the predetermined position in the cooling duct and thus merely prevents the insert body from slipping in the cooling duct and the insert body from being deformed under the pressure of the coolant flowing through the cooling duct. Analogously, the at least one projection does not produce a conventional force-fit connection which is generally known in connection technology, but rather holds the insert body at the predetermined position in the cooling duct and thus merely prevents the insert body from slipping in the cooling duct and the insert body from being deformed under the pressure of the coolant flowing through the cooling duct. If required, the insert body can be taken out of the cooling duct or exchanged non-destructively in these two cases.The insert body can be connected to the cooler part in a materially integral manner, such as, for example, welded or soldered or adhesively bonded, and can thus be held fixed in the cooling duct in a non-movable manner.According to a second aspect of the invention, an electronic device or a power electronic device is provided which forms, for example, a part of a (power) converter or a (power) CCD converter.The electronics device has at least one electronics module (or power electronics module) and at least one previously described cooler for cooling the at least one electronics module, wherein the at least one electronics module is in thermal contact with the at least one cooler.Furthermore, an inverter or a power inverter is provided, which has a previously described (power) electronic device and an inverter driver circuit for operating the at least one (power) power source of the (power) electronic device. The driver circuit is connected to the at least one (power) driver circuit by means of at least one signal connection in terms of signal technology or electrically.In addition, a DC / DC converter or a power DC / DC converter is provided, which has a previously described (power) electronic device and a DC / DC converter driver circuit for operating the at least one (power) power source of the (power) electronic device. The driver circuit is connected to the at least one (power) driver circuit by means of at least one signal connection in terms of signal technology or electrically.DESCRIPTION OF THE DRAWINGAn exemplary embodiment of the invention is explained in more detail below with reference to the accompanying drawing. In this case, the single FIG. 1 shows a schematic cross-sectional illustration of a (power) electronic device EV having a cooler KL according to the exemplary embodiment of the invention. The device EV forms, for example, a power electronics part of a power inverter for an electric drive of a motor vehicle.The device EV has a power electronics module EM with SiC semiconductor switches and a cooler KL for cooling the device EV or the module EM.The cooler KL has a cooler part KT as a cooler cover and a cooler base KB and cooler side parts (not shown in the figure) which together form a cooling duct KN and enclose the latter apart from an inlet and an outlet (both not shown in the figure).The cooler KL also has a coolant-permeable sponge-like insert body EK which is formed as a one-piece or one-piece three-dimensional structure or knitted fabric from a multiplicity of elastic copper threads or copper wires (made of high thermal conductivity copper or a high thermal conductivity copper alloy) with many cavities surrounded only partially by these. The insert body EK is designed to be elastically compressible owing to the elastic copper threads or wires and the hollow spaces surrounded by these in part and additionally has a certain mechanical rigidity.In alternative embodiments, the insert body may be formed as a three-dimensional nonwoven or woven fabric of a metal or a graphite-based material or copper or a copper alloy, or as a three-dimensional foam body of a metal or a graphite-based material or copper or a copper alloy, with many only partially enclosed cavities.The insert body EK is arranged in the cooling duct KN and is clamped in a non-movable manner between the cooler part KT and the cooler base KB and the cooler side parts and is thus physically and thermally directly contacted with these cooler parts KT, KB. During assembly, the insert body EK is compressed by the aforementioned cooler parts KT, KB and thus compressed slightly elastically, whereby static friction arises between the insert body EK on the one hand and the cooler parts KT, KB, which prevents the insert body EK from moving or slipping in the cooling channel KN-especially during operation of the cooler KL. To increase the static friction, the surfaces OF 1 of the above-mentioned cooler parts KT, KB facing the cooling channel KN can be specially roughened by means of an abrasive production method, such as e.g. by direct laser beam interference structuring, or an abrasive production method, such as e.g. by fine powder coating. In addition, the cooler part KT has, on the surface OF 1 facing the cooling channel KN, a number of pin-shaped projections VS which engage into the insert body EK away from the surface OF 1 and thus prevent the insert body EK from displacing or slipping in the cooling channel KN (in the flow direction of the coolant).On a surface OF 2 of the cooler part KT facing away from the cooling channel KN, the aforementioned power electronics module EM of the device EV is arranged and physically and thermally connected to the latter. In an alternative embodiment, the cooler part KT can be formed directly as a circuit carrier of the module EM and at the same time as a part of the module EM.During operation of the device EV, the waste heat which is generated by the power semiconductors, such as the SiC semiconductor switches, on the module EM is transferred via the cooler part KT to the insert body EK which is directly thermally contacted with the cooler part KT or to the numerous copper threads or wires thereof and is discharged from these directly to the coolant flowing through the cavities between the threads / wires.

Claims

An electronic cooler (KL) for cooling an electronic device (EV), comprising: - a cooling channel (KN) for passing a liquid coolant through it; - a cooler part (KT) which at least partially surrounds the cooling channel (KN); - a coolant-permeable, integrally formed, sponge-like insert body (EK) made of a thermally conductive material, which is arranged in the cooling channel (KN) and is thermally contacted with the cooler part (KT) and is held in the cooling channel (KN) such that it cannot be moved by the cooler part (KT); - wherein the cooler part (KT) has a surface (OF1) facing the cooling channel (KN) and is roughened to increase the surface area; wherein the roughened surface holds the insert body (EK) in the cooling channel (KN) in a non-movable manner.Cooler (KL) according to Claim 1, wherein the insert body (EK) is of compressible design and the cooler part (KT) holds the insert body (EK) in the cooling duct (KN) in a non-movable manner by action of a compressive force on the insert body (EK).Cooler (KL) according to claim 1 or 2, wherein the insert body (EK) is a three-dimensional knit of wires made of a metal or a graphite-based material or made of copper or a copper alloy.The cooler (KL) according to claim 1 or 2, wherein the insert body (EK) is a three-dimensional nonwoven fabric made of a metal or a graphite-based material or copper or a copper alloy.The cooler (KL) according to claim 1 or 2, wherein the insert body (EK) is a three-dimensional fabric made of a metal or a graphite-based material or copper or a copper alloy.The cooler (KL) according to claim 1 or 2, wherein the insert body (EK) is a three-dimensional foam body made of a metal or a graphite-based material or copper or a copper alloy.Cooler (KL) according to one of the preceding claims, wherein the cooler part (KT) holds the insert body (EK) in the cooling channel (KN) in a non-movable manner in a positive-locking or non-positive-locking or materially integral manner.Cooler (KL) according to one of the preceding claims, wherein the surface (OF1) is roughened by means of an abrasive manufacturing method or by means of an abrasive manufacturing method.Cooler (KL) according to one of the preceding claims, wherein the cooler part (KT) has on the surface (OF1) at least one projection (VS) which projects into the cooling duct (KN) in the form of a pin and which holds the insert body (EK) in the cooling duct (KN) in a non-movable manner.Cooler (KL) according to one of the preceding claims, wherein the insert body (EK) is connected to the cooler part (KT) by material bonding or welded or soldered or glued.Electronic device (EV), comprising: - an electronic module (EM); - a cooler (KL) according to one of the preceding claims; - wherein the electronic module (EM) is thermally contacted with the cooler (KL).Inverter, comprising: - an electronic device (EV) according to claim 11; - a driver circuit for operating the electronic module (EM), which driver circuit is connected to the electronic module (EM) via a signal connection.

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