WO2025224014A1

WO2025224014A1 - Cooling insert for a vehicle module with a housing and an electronic unit arranged in the housing and manufacturing method for the vehicle module

Info

Publication number: WO2025224014A1
Application number: PCT/EP2025/060751
Authority: WO
Inventors: Stefan WUJANICZ; Erim CAKIR; Gowtham Chinnapandi
Original assignee: Connaught Electronics Ltd
Current assignee: Connaught Electronics Ltd
Priority date: 2024-04-24
Filing date: 2025-04-17
Publication date: 2025-10-30
Anticipated expiration: 2026-10-24
Also published as: DE102024111435A1

Abstract

The invention relates to a vehicle module (1) and a manufacturing method for the vehicle module (1). The vehicle module (1) comprises a housing (3) and an electronic unit (4) arranged in the housing (3). The housing (3) comprises a housing part (10) with an opening (16) that is directly sealed with an insert (11) of the housing (3) by thermal bonding. The housing part (10) is made of a first material with a first thermal conductivity and the insert (11) is made of a second material with a second thermal conductivity that is higher than the first thermal conductivity. The insert (11) is configured to dissipate heat emitted by the electronic unit (4).

Description

COOLING INSERT FOR A VEHICLE MODULE WITH A HOUSING AND AN ELECTRONIC UNIT ARRANGED IN THE HOUSING AND MANUFACTURING METHOD FOR THE VEHICLE MODULE

The invention relates to a vehicle module with a housing and an electronic unit arranged in the housing. Besides, the invention relates to a vehicle with such a vehicle module and a manufacturing method for such a vehicle module.

A vehicle may comprise at least one vehicle module with an electronic unit. Such a vehicle module may be a control device of the vehicle, in particular an electronic control unit (ECU).

Increasing power requirements for automotive control devices, in particular for ECUs, lead to the development of innovative cooling solutions capable of carrying away heat created by electronic components of the electronic unit. However, known passive and/or active cooling solutions become insufficient for the most demanding and hence complex applications in the vehicle. Therefore more complex cooling solutions are required to cope with the increasing power requirements.

It is the object of the invention to provide cooling for a vehicle module with sufficient cooling performance for complex applications in a vehicle.

The independent claims solve the object.

A first aspect of the invention relates to a vehicle module with a housing and an electronic unit arranged in the housing. The housing comprises a housing part with an opening. The opening may alternatively be referred to as a hole in the housing part. The opening extends from a first side of the housing part that faces an inside of the housing to a second side of the housing part that faces an environment of the vehicle module. The first side is opposite the second side. The inside of the housing forms a volume space in which at least the electronic unit is positioned.

The opening is directly sealed with an insert of the housing by thermal bonding. The insert is a part of the housing. The insert closes the opening in the housing part. Directly sealed means that the housing part at an edge of the opening on one hand and an edge of the insert adjoining the housing part on the other hand are directly connected to each other. For example, there is no component or layer positioned between the housing part at the edge of the opening and the edge of the insert. Hence, there is, for example, no separate solder material plate or braze plate arranged between the housing part and the insert.

The housing part is made of a first material with a first thermal conductivity. The insert is made of a second material with a second thermal conductivity that is higher than the first thermal conductivity. The thermal conductivity of a material, here of the respective material, is a measure of the material’s ability to conduct heat. It may be described by a material specific value given in watt per meter and kelvin. The first material and the second material differ from one another. In a preferred example, the first material and the second material are metals. The first material may alternatively be referred to as a first metal and the second material may alternatively be referred to as a second metal. The insert is configured to dissipate heat emitted by the electronic unit. The heat dissipation is at least enhanced, in particular driven, by the higher thermal conductivity of the insert with respect to the thermal conductivity of the housing part surrounding the insert.

In the thermal bonding process to create the thermal bond, both materials blend and their atoms mix. This results in forming a hybrid material made of the first material and the second material. The thermal bond is, for example, leak-resistant so that no fluid may leak in or out of the housing at the insert. In other words, the housing part and the insert that are thermally bonded to one another form a housing that is made from a hybrid material. The hybrid material comprises the first material and the second material. Using such a housing significantly increases the thermal efficiency of the vehicle module because of the highly conductive second material used for the insert compared to the thermal conductivity of the first material chosen for the housing part. The second material with the high thermal conductivity is only used in a specific area of the housing. The specific area may be an area that requires high heat dissipation compared to other areas of the housing. In an example, the insert may be embedded in a cooling channel for active cooling of the electronic unit, for example, if the housing comprises a cooling channel.

The invention is based on the observation that a housing for a vehicle module may be made from machined or casted aluminum as aluminum provides a relatively good ratio of thermal conductivity and robustness to its cost. However, increasing power requirements for modern vehicle modules may make this solution obsolete as the thermal conductivity of aluminum is about 190 watt per meter and kelvin. Therefore, materials that offer higher thermal conductivities are required, for example copper with a thermal conductivity that may reach 400 watts per meter and kelvin. This example for a material with a high thermal conductivity is however relatively expensive. Hence, it is not cost effective to make entire housings of vehicle modules from copper. Therefore, the housing should be made from a hybrid material, for example, by using an aluminum casted or machined housing part with the thermally bonded insert made from the high conductivity material such as copper.

This solution also eliminates the housing part, for example an aluminum layer of the housing part made of aluminum, from the thermal stack, meaning that heat dissipated from high power components of the electronic unit is only transported through the highly conductive layer given by the insert and does not have to be transported through an additional layer of the housing part.

In summary, the vehicle module provides cooling with sufficient cooling performance for complex applications in a vehicle by using the insert with high thermal conductivity for fast and reliable heat transfer from the electronic unit to the environment of the vehicle module. Thus, the insert may be understood as a heat sink or heat sink unit of the vehicle module and/or may be connected to a heat sink unit of the vehicle module.

An embodiment comprises that the insert comprises a first side facing an inside of the housing, wherein the first side is thermally directly coupled to the electronic unit by at least one thermal coupling element. The thermal coupling element may be a thin layer with a thickness of about 0.5 millimeter. Thicker or thinner thermal coupling elements are however possible. The thermal coupling element may be as thin as possible to maximize the thermal performance of the vehicle module. The thermal coupling element is in particular made of a thermal interface material (TIM). The TIM may be a thermal paste, a thermal adhesive, a thermal gap filler, a thermally conductive pad, a thermal tape and/or another kind of material that is configured to enhance the thermal coupling between the first side of the insert and the electronic unit.

The electronic unit may comprise a printed circuit board (PCB) with at least one electronic component. The thermal coupling element is then in a preferred example positioned between the at least one electronic component and the insert, wherein the thermal coupling element touches the first side and the electronic component directly, in particular over an entire surface of the first side and an entire surface of the electronic component. In this example, the electronic component is a heat-producing device and the insert is a heat-dissipating device. If there are multiple electronic components, there may be some electronic components with no insert next to them. The insert may be positioned on selected components of the electronic unit, for example, on such components that produce a particularly high amount of heat compared to other components.

For example, copper as second material provides excellent thermal conductivity in all directions so heat spreading may not be the only function of the hybrid housing. Another major advantage of the hybrid housing is evacuating the heat from the electronic unit by directly taking the heat from hot components of the PCB through the thermal coupling element and carrying the heat away by a passive air cooling system provided by the environment of the vehicle module.

A preferred embodiment comprises that the electronic unit comprises multiple heat emitting electronic components. The multiple heat emitting electronic components are in particular grouped together on the electronic unit, for example on the PCB. This means that in a preferred example, all high power components on the PCB are grouped together so that a common insert, for example, one single material plate made of the second material, is sufficient for all the components that require cooling. The insert shared by the high power components that is bonded to the housing part optimizes the design of the vehicle module and reduces its overall costs. Alternatively, the vehicle module may comprise multiple inserts, each of which seals one of multiple openings in the housing part.

The vehicle module comprises multiple thermal coupling elements. At least two of the multiple heat emitting electronic components are thermally directly coupled to the first side by spatially separated thermal coupling elements. This means that the multiple heat emitting electronic components are grouped in a way that one insert is sufficient, however there may be gaps between the multiple heat emitting electronic components so that multiple individual thermal coupling elements may be used to thermally couple the multiple heat emitting electronic components with the first side of the insert. This results in a minimal use of thermal coupling elements which may contribute to reduce the overall costs of the vehicle module.

According to another embodiment, the insert comprises a base plate with the first side and the opposite second side. Moreover, the insert comprises at least one fin extending from the base plate at the second side. In a preferred example, the insert comprises multiple fins. The multiple fins may be located adjacent to each other on the second side. They may be oriented parallel to each other. In other words, the insert has at least one fin on its top surface that faces away from the inside of the housing, wherein the at least one fin dissipates heat to the environment of the housing and thus to the surroundings of the vehicle module. The fin may alternatively be referred to as a rib. A cross section of the fin at a first end that is connected to the second side may be larger than a cross section of the fin at a second end opposite the first end. In this example, the fin has a tapering form. At the second end, the fin may be flattened or pointed. The heat emitted from the electronic components of the electronic unit is thus quickly spread within the insert because of its high thermal conductivity, wherein the heat is spread from the base plate to the fin and given off to the air surrounding the at least one fin. This ensures a rapid heat transfer from the high power electronic components to the outside of the vehicle module and passive cooling with a natural air flow passing between the fins.

The base plate may have a length and/or width that is larger than a thickness of the base plate, wherein the thickness is viewed in a direction perpendicular to a surface of the housing element. The thickness of the base plate may be at least equal to or bigger than a thickness of the housing part at the edges of the opening. The length and width of the base plate at the second side may match a length and width of the opening, so that the insert may fit into the opening with its base plate. At the first side, the length and/or width of the base plate may be equal to or bigger than the length and/or width of the opening so that the base plate may overlap the opening in the inside of the housing.

A preferred embodiment comprises that the vehicle module comprises at least one fan located adjacent to the at least one fin so that an airflow generated by the at least one fan is parallel to the at least one fin. This means that the hybrid housing is cooled with an active air cooling system, which is here the at least one fan. The insert embedded in the housing part may comprise multiple fins on an outer surface of the housing part that faces away from the inside of the housing. The multiple fans are directly exposed to a forced air flow induced by the at least one fan. This ensures a rapid heat transfer from the electronic unit to the environment of the vehicle module and a rapid cooling with a forced air flow passing between the fins.

Moreover, an embodiment comprises that the at least one fan is located on the outer surface of the housing part. In particular, it is located directly next to the at least one fin. The fan is thus directly attached to the hybrid housing in a way that it can direct an air flow that is parallel with the fins. Alternatively, there may be an intermediate element positioned between the fan and the outer surface. The at least one fan may be fixed on the housing part, for example, it may be glued and/or screwed to the housing part. Alternative or additional fixing techniques may be applied. There may be an air gap between the at least one fan and the insert. Once the heat is transferred into the fins, it is quickly and reliably removed by the air flowing between the fins.

A further embodiment comprises that the vehicle module comprises a cooling plate that is thermally directly coupled to the insert by a thermal coupling element on a second side of the insert facing away from the inside of the housing. In a preferred example, the second side has a flat surface. The insert may be shaped as a plate with a flat first surface and a flat second surface. The cooling plate may comprise at least one cooling channel with a cooling fluid passing through. The cooling fluid may be water or another cooling liquid or coolant. This means that the hybrid housing is cooled with a fluid, in particular a liquid, passing through the cooling channel provided by the cooling plate that is attached to the top surface (second side) of the insert. The cooling plate is a separate part of the vehicle module. A length and/or width of the cooling plate may be at least equal to or bigger than the length and/or width of the second side of the insert. The thermal coupling element on the second side may be a TIM. It may be of a same thermal coupling element type as the thermal coupling element between the electronic unit and the first side of the insert. Alternatively, the thermal coupling elements differ from one another. The thermal coupling element on the second side is used to provide a good thermal conductivity between the insert and the housing part on one side and the cooling plate on the other side. This is applicable to modular vehicle modules in which, for example, removable modules or cartridges are added to a main ECU unit. The cooling plate may be mounted in the main ECU unit. The heat passes through the thermal coupling element applied onto a hot component of the electronic unit, then it is conducted through the insert in the hybrid housing and is carried away by the coolant flowing in the cooling channel of the cooling plate.

Furthermore, an embodiment comprises that the insert comprises at least a part of at least one cooling channel for a cooling device of the vehicle module. If the insert is just a part of the cooling channel, it may be mechanically fixed to surrounding parts of a channel bottom and channel side walls of the cooling channel. The channel bottom and channel side walls are then parts of the housing part. This means that the hybrid housing is actively cooled with a cooling fluid passing through a cooling channel embedded in the housing. For example, the cooling device may comprise multiple cooling channels that form a cooling circuit that extends over a specific area of the housing part. At least a subarea of the area is provided by the insert. The cooling device allows a particularly rapid and effective cooling which is even enhanced by the insert made of the second material with the high thermal conductivity so that heat from the electronic unit reaches the cooling device fast and effectively.

Another embodiment comprises that the insert provides at least a part of a bottom part of the at least one cooling channel. The housing comprises a cover plate attached to the housing part, wherein the cover plate provides a top part of the at least one cooling channel and covers the cooling device towards the environment of the vehicle module. In other words, a bottom of the cooling channel comprises the embedded insert that is thermally bonded to the casted or machined housing part. Heat carried away from the electronic unit is passed directly from, for example, fins on the second side of the insert to the coolant flowing around the fins, if the fins extend on the second side. The thermal bond between the insert and the housing part is also leak-proof which ensures that no leakage between these parts occurs. Besides, no leakage is possible at the top part because of the attached cover plate. The cover plate may be mechanically attached to the housing part. For example, it may be welded or glued to the housing part. The cover plate may be made of the first material, another material or plastic, for example. The cover plate may be welded, in particular friction stir welded, to the housing part of the housing.

According to another embodiment, the insert comprises the base plate with the first side facing the inside of the housing and the opposite second side. The opposite second side faces the cover plate. At least one thermal element extends from the base plate at the second side. The at least one thermal element is in particular at least one fin and/or at least one pin and/or at least one turbulator. Higher power requirements for the electronic unit may require the insert to have a more sophisticated design for higher thermal conductivity by the cooling device. This may be achieved by at least one additional thermal feature, which is here the at least one thermal element. Besides fins, pins, and/or turbulators, other design features increasing the cooling efficiency of the cooling device may be possible. The at least one thermal element hence increases cooling efficiency of the cooling device of the vehicle module. According to a preferred embodiment, the first material is aluminum and/or the second material is copper and/or silver. Alternatively, the first material may be another material with a thermal conductivity that deviates from the thermal conductivity of aluminum by less than 20 percent, in particular less than 10 percent or 5 percent. Alternatively, the second material may be another material with a thermal conductivity that deviates from the thermal conductivity of copper and/or silver by less than 20 percent, in particular less than 10 percent or 5 percent. Thus, the first material may be a cheaper material than the second material, however the higher thermal conductivity of the second material makes it particularly advantageous for use in the insert.

In a preferred example, the vehicle module is the control device, in particular the ECU of a vehicle. The electronic unit may be a system-on-chip unit or may comprise a system-on- chip unit. It may alternatively be referred to as SoC unit. The control device may be understood as a computing unit or as a data processing device with processing circuitry. The control device may therefore perform computing operations in order to process data.

In particular, a vehicle-centric, zone-oriented architecture of the electrical or electronic components of the vehicle can be provided for the vehicle. In particular, at least one main controller, for example a single main controller, can be provided in such a vehicle architecture, which can also be referred to as the main control unit or vehicle computer, and which can be designed to perform the main computing operations for vehicle-specific applications, for example autonomous driving.

The main controller may be connected to several, preferably four, zonal controllers, which may also be referred to as zone controllers, by means of signaling technology. Zonal controllers can be designed to perform less demanding computing operations compared to the main computing operations of the main controller.

For example, the electronic vehicle architecture can be divided into zones, preferably four zones, wherein a zonal controller can be provided for each zone. In particular, the main controller can be connected via the zonal controllers to other electrical and electronic components of the vehicle, in particular to smaller, distributed control units, as well as to a large number of sensors and actuators of the vehicle.

Such a vehicle-centric, zone-oriented architecture of the electrical or electronic components can be advantageous at least to the extent that they are less complex than domain-oriented architectures. In particular, the computing operations of the complex, vehicle-specific applications of distributed control units can be consolidated on a single or on a few, very powerful main controllers.

Preferably, the vehicle module can be a main controller of the vehicle. Alternatively, the vehicle module may be a zonal controller of the vehicle. Accordingly, the insert may be provided for cooling the powerful electronic components of a main controller or a zonal controller.

Another aspect of the invention relates to a vehicle with a vehicle module as described above. The vehicle may be a motor vehicle, for example, a passenger car, a truck, a bus, a motorcycle and/or a moped.

A further aspect of the invention relates to a manufacturing method for a vehicle module. The vehicle module comprises a housing and an electronic unit arranged in the housing. The housing comprises a housing part with an opening and an insert. The housing part is made of a first material with a first thermal conductivity and the insert is made of a second material with a second thermal conductivity that is higher than the first thermal conductivity. The opening in the housing part is sealed with the insert by thermal bonding. Thermal bonding may be achieved at least partially by brazing, soldering and/or friction stir welding. The insert is configured to dissipate heat emitted by the electronic unit.

In other words, the housing part is manufactured from the machined or casted first material, which is in particular aluminum. The insert is made from a highly heat conductive material, such as copper as the second material. The insert is placed in the opening in the housing part and then is thermally bonded to the housing part. Thermal bonding includes brazing, soldering and welding. That forms a hybrid housing consisting of two materials which provides a lot of advantages. For example, the thermal bonding makes the housing water-tight so that no leakage can occur in the bonded location.

A preferred embodiment of the manufacturing method comprises that the insert is provided with a material allowance at least on the first side facing the inside of the housing. The insert has thus more of the second material at least on a bottom side or underside of the insert than necessary. The material allowance allows to compensate for bonding process inaccuracies, for example, by post-processing the insert after the thermal bonding. This improves the fixation of the insert in the opening of the housing part. Another embodiment of the manufacturing method comprises that at least the first side and/or the opposite second side of the insert is machined after the thermal bonding so that a surface of the machined side has a roughness in a predefined roughness range and/or a flatness in a predefined flatness range. For example, the bottom surface of the insert, which is here the surface of the first side, needs to be machined after the bonding process to achieve a required surface roughness, a required thermal gap for the thermal coupling element and/or sufficiently good flatness. The predefined roughness range may be below a roughness parameter R_a of 3.2 micrometers. In this predefined roughness range, thermal conduction from the electronic unit, in particular the thermal coupling element, to the insert is increased compared to an insert with a rougher surface. If the flatness is in the predefined flatness range a direct contact surface of the insert is increased compared to a surface with a worse flatness. The flat design prevents, for example, air gaps from forming between recesses and/or material piles on the surface.

If the second side of the insert is flat and, for example, without fins, it should be machined after the bonding process as well. This means that a top surface of the insert, which is here the second side, may be skimmed for a sufficiently good surface roughness and flatness that are, for example, needed for a reliable contact with the cooling plate. This machining of the second side may achieve that the second side has a roughness in the predefined roughness range and/or a flatness in the predefined flatness range.

Requirements in roughness and/or flatness may be the same or different for both sides of the insert.

The embodiments described in connection with the vehicle module or the manufacturing method, both individually and in combination with each other, apply accordingly, when applicable, to the manufacturing method or the vehicle module, respectively. They apply accordingly to the vehicle. The invention comprises combinations of the described embodiments.

The figures show in:

Fig. 1 a schematic representation of a vehicle with a vehicle module;

Fig. 2 an exploded view of a first embodiment of a vehicle module;

Fig. 3 a schematic cross-section view of the embodiment of Fig. 2; Fig. 4 an exploded view of the embodiment of Fig. 2 and Fig. 3 with multiple electronic components;

Fig. 5 an exploded view of a second embodiment of a vehicle module;

Fig. 6 a schematic cross-section view of the embodiment of Fig. 5;

Fig. 7 an exploded view of the embodiment of Fig. 5 and Fig. 6 with multiple electronic components;

Fig. 8 a schematic representation of the embodiment of Fig. 5 to Fig. 7 with two fans;

Fig. 9 an exploded view of a third embodiment of a vehicle module;

Fig. 10 a schematic cross-section view of the embodiment of Fig. 9;

Fig. 11 an exploded view of the embodiment of Fig. 9 and Fig. 10 with multiple electronic components;

Fig. 12 an exploded view of a fourth embodiment of a vehicle module;

Fig. 13 a schematic cross-section view of the embodiment of Fig. 12; and

Fig. 14 an exploded view of the embodiment of Fig. 12 and Fig. 13 with multiple electronic components.

In the figures, the same components are indicated with same reference signs.

Fig. 1 shows a vehicle module 1 that is comprised by a vehicle 2. The vehicle 2 may be a motor vehicle 2. The vehicle module 1 may be a control device of the vehicle 2, in particular, it may an electronic control unit (ECU). The vehicle module 1 may be configured to provide a function for the vehicle 2, such as a driver assistance system.

Fig. 2 shows a first embodiment of the vehicle module 1 . The vehicle module 1 comprises a housing 3 and an electronic unit 4 arranged in the housing 3. The electronic unit 4 comprises in this example a printed circuit board (PCB) 5 and at least one electronic component 6 that is electronically coupled to the PCB 5. Moreover, the electronic unit 4 may comprise multiple connectors 7, 8, 9, for example, for connection with other vehicle modules 1 , a power supply, a sensor device of the vehicle 2 and/or any other electronic device in the vehicle 2. The multiple connectors 7, 8, 9 may comprise a PCB connector, a High-Speed Modular Twisted-Pair Data (H-MTD) connector and/or a FAKRA connector (FAKRA for the German standard “Fachkreis Automobil”). Other connectors 7, 8, 9 may be possible.

The housing 3 comprises a housing part 10. When viewed in height direction (z-direction), this housing part 10 may be an upper part of the housing 3. The housing part 10 is made of a first material, in particular a first metal, with a first thermal conductivity. In a preferred example, this first material is aluminum. The housing 3 comprises an insert 11 that is thermally bonded to the housing part 10 in an opening 16 (see reference sign 16 in Fig. 3) of the housing part 10. The opening 16 of the housing part 10 is directly sealed with the insert 11 of the housing 3 by thermal bonding.

The insert 11 is made of a second material, in particular a second metal, with a second thermal conductivity. The second thermal conductivity is higher than the first thermal conductivity. In a preferred example, the second material is copper or silver. The insert 11 is configured to dissipate heat emitted by the electronic unit 4. More precisely, the heat may be emitted by the electronic component 6, in particular, if it is a high power electronic component 6.

In the sketched example, there may be a thermal coupling element 12 located between the electronic component 6 and the insert 11 . The thermal coupling element 12 may be made of a thermal interface material (TIM), such as a thermal paste.

The housing part 10 may comprise at least one screw 13, in particular a captive screw 13, to join the vehicle module 1 to a rack chassis by means of threaded connection. When fastening the at least one screw 13, the housing 3 remains securely attached to the rack chassis. This also allows quick assembly. The at least one screw 13 can be screwed by hand and/or by screwdriver.

The vehicle module 1 may comprise a housing bottom 14. The housing bottom 14 may be connected to the PCB 5 and the housing part 10 by at least one screw 15. In this connected state the housing 3 is assembled (not sketched here). In the connected state, the electronic unit 4 is located in an inside of the housing 3. Fig. 3 shows a cross-section view of the first embodiment. The cross-section shows the opening 16 which is here already sealed with the insert 11 . The insert 11 comprises a first side 17 facing the inside of the housing 3 with the electronic unit 4. The first side 17 is thermally directly coupled to the electronic unit 4. Here, the first side 17 is thermally directly coupled to the electronic component 6 by the thermal coupling element 12.

Opposite the first side 17, the insert 11 comprises a second side 18 that faces an environment of the vehicle module 1 . The insert 11 may comprise a base plate 19 and at least one fin 20 extending from the base plate 19 at the second side 18. Here, the insert 11 comprises multiple fins 20 which are arranged parallel to each other. The at least one fin 20 may alternatively be referred to as a rip. The base plate 19 may comprise a flat surface on the first side 17.

As an example, the base plate 19 may comprise protrusions 21 at the first side 17 so that, for example, a width and/or length of the base plate 19 is bigger at the first side 17 compared to the second side 18. This increases a surface area of the insert 11 that is in direct contact with the housing part 10 at an edge of the opening 16. At this surface area the insert is thermally bonded to the housing part 10. The thermal bonding may be achieved by, for example, brazing, soldering and/or friction stir welding.

The insert 11 may be provided with a material allowance at least on the first side 17. For example, at least the first side 17 is machined after the thermal bonding so that a surface of the machined side, which may be the first side 17 and/or at least partially the second side 18, has a roughness in a predefined roughness range and/or a flatness in a predefined flatness range. As a result, the direct thermal contact with the thermal coupling element 12 on the first side 17 may be particularly effective.

In Fig. 3, heat arrows 22 show possible directions of heat emitted by the electronic unit 4, more precisely by the heat emitting electronic component 6. The heat is then transported through the thermal coupling element 12 to the insert 11 and then transported towards the environment of the vehicle module 1 .

Fig. 4 shows an example of the first embodiment with multiple heat emitting electronic components 6 and multiple thermal coupling elements 12. The multiple heat emitting electronic components 6 are grouped together on the PCB 5. As an example, there are three adjacent thermal coupling elements 12 as well as multiple heat emitting electronic components 6. At least two of the multiple heat emitting electronic components 6 may be thermally directly coupled to the first side 17 by spatially separated thermal coupling elements 12. Here, there is one separate thermal coupling element 12 for each one of the three heat emitting electronic components 6. However, the one insert 11 covers all the heat emitting electronic components 6.

In an alternative and not sketched example, there may be multiple regions on the PCB 5 with at least one heat emitting electronic component 6 each. In this example, the housing part 10 may have multiple openings 16 which are each directly sealed with an individual insert 11 so that an insert 11 may be provided for each one of the regions with the at least one heat emitting electronic component 6. Alternatively, the one insert 11 may be so large that is covers all regions with heat emitting electronic components 6.

Fig. 5 shows an exploded view of a second embodiment of the vehicle module 1 . The vehicle module comprises at least one fan 23. The at least one fan 23 is located adjacent to the at least one fin 20 so that an airflow generated by the at least one fan 23 is parallel to the at least one fin 20. The fan 23 may be located on an outer surface 24 of the housing part 10. The at least one fan 23 is here located directly next to the insert 11 with the fins 20. The outer surface 24 faces away from the inside of the housing 3 and thus faces the environment of the housing 3 and the vehicle module 1 .

Fig. 6 shows a cross-section view of the second embodiment with two fans 23 located next to each other. Fig. 6 also shows the example that there are multiple thermal coupling elements 12 for multiple individual heat emitting electronic components 6 grouped together on the PCB 5. In the example for the second embodiment, the insert 11 comprises the base plate 19 and the extending fins 20.

Fig. 7 shows an example of the second embodiment with multiple separate thermal coupling elements 12. This also shows how two fans 23 may be located with respect to the fins 20 next to the second side 18 of the insert 11 on the outer surface 24. More fans 23 than two fans 23 may be possible.

Fig. 8 shows a section of Fig. 7 in more detail. It shows a cold airflow 25 attracted by the fans 23 and directed towards the fins 20. Behind the fins 20, a warmer airflow 26 compared to the cold airflow 25 can be detected because the cold airflow 25 is heated up by the heat dissipated by the insert 11 . Fig. 9 shows a third embodiment of the vehicle module 1 . Here, the insert 11 , is shaped as a plate. It thus may only comprise the base plate 19. The surface of the insert 11 is flat on both the first side 17 and the second side 18. Moreover, the vehicle module 1 comprises a cooling plate 27 that is thermally directly coupled to the insert 11 by a thermal coupling element 12 on the second side 18 of the insert 11 . The cooling plate 27 may be configured for active cooling, meaning that a cooling fluid, such as a coolant or cooling liquid, may pass through cooling channels in the cooling plate 27 (not sketched here). The third embodiment may comprise two thermal coupling elements 12, one on the first side 17 and another one on the second side 18. They may vary in size. For example, the size of the thermal coupling element 12 that is directly coupled to the first side 17 may depend on a size of the heat emitting electronic components 6, whereas the size of the thermal coupling element 12 between the second side 18 and the cooling plate 27 may depend on a size of the second side 18 of the insert 11 . In a preferred example, the thermal coupling element 12 covers at least an entire surface of the insert 11 on the first side 17 or second side 18, respectively. Alternatively, the thermal coupling element 12 may cover the first side 17 or second side 18 only partially.

Fig. 10 shows the third embodiment in a cross-sectional view. This better indicates the different sizes of the two thermal coupling elements 12 that may be used here. It also shows that the cooling plate 27 may be larger in width and/or length than the insert 11 so that, for example, only a part of the cooling plate 27 is in contact with the insert 11 via the thermal coupling element 12.

Fig. 11 shows an example of the third embodiment with multiple separate thermal coupling elements 12 between the insert 11 and the heat emitting electronic components 6. Therefore in this example, the insert 11 is bigger in a length direction (x-direction) compared to, for example, the insert 11 shown in Fig. 9. As a result, the insert 11 covers all heat emitting electronic components 6 on the PCB 5 and a larger part of the cooling plate 27 compared to Fig. 9.

Fig. 12 shows a fourth embodiment of the vehicle module 1 . Here, the insert 11 comprises at least a part of at least one cooling channel 28 for a cooling device 29 of the vehicle module 1 . Here, the insert 11 comprises only a part of the cooling channel 28 and the cooling device 29. Thus, the insert 11 is here surrounded by parts of the cooling channel 28 provided by the housing part 10, meaning that the housing part 10 comprises the rest of the cooling channel 28 or the rest of the cooling device 29. The insert 11 may be mechanically fixed to surrounding parts of the cooling device 29. For example, the edges of the insert 11 may be connected to a channel bottom or a channel side wall of the cooling channel 28 of the cooling device 29, respectively. In a preferred example, the cooling device 29 is a liquid cooling device through which a cooling liquid is running.

The housing 3 may comprise a cover plate 30 attached to the housing part 10. The cover plate 30 provides a top part of the at least one cooling channel 28 and covers the cooling device 29 towards the environment of the vehicle module 1 . In particular, the cover plate 30 is made from the first material and friction stir welded to the housing part 10 made of the same first material.

Fig. 13 shows a cross-section view of the fourth embodiment with the insert 11 as the bottom of the cooling channel 28. The connection between the insert 11 and, for example, other bottom parts of the cooling channel 28 and/or the side walls of the cooling channel 28 may be provided by mechanical attachment such as welding or cluing. The insert 11 may be understood as a base plate 19 with the first side 17 facing the inside of the housing 3 and the opposite second side 18 facing the cover plate 30. There may be at least one thermal element 31 extending from the base plate 19 at the second side 18. The at least one thermal element 31 may be, for example, at least one fin 20 as sketched here. Alternatively or additionally, it may be at least one pin and/or at least one turbulator. In the empty spaces between the insert 11 , the housing part 10 and the cover plate 30 the cooling fluid may flow or stream.

Fig. 14 shows an example of the fourth embodiment with multiple heat emitting electronic components 6 as well as multiple separate thermal coupling elements 12.

Compared to the first embodiment, the other embodiments show combinations with active cooling techniques by means of the at least one fan 23, the cooling plate 27 or the cooling device 29, respectively.

The sketched sizes and proportions of the individual features in the Figs., in particular of the insert 11 , may be dependent on a specific use case and have to be understood as examples.

In summary, the invention relates to a hybrid housing for a control device for a vehicle 2 with passive air cooling and optional additional active air cooling. The housing 3 may be made from casted or machined aluminum. A highly conductive heat spreader, such as the insert 11 made from copper, is embedded in the aluminum housing 3 and is thermally bonded to the aluminum, forming a hybrid material. Thermal bonds between aluminum and copper parts include brazing, soldering and friction stir welding. Both materials blend in the thermal bonding process and their atoms mix, forming the hybrid material. This bond is also leak-resistant, which makes it possible to use it in cooling channels 28. The insert 11 may have the fins 20 on the top surface that dissipate heat to its surroundings.

The insert 11 has material allowance on the underside to compensate for bonding process inaccuracies. A bottom surface of the insert 11 (first side 17) needs to be machined after the bonding process. This is to achieve the required surface roughness, thermal gap for the thermal coupling element 12 as well as good flatness. In case of the third embodiment, the insert 11 may have material allowance on both sides 17, 18 to compensate for bonding process inaccuracies. The second side 18 has to be skimmed for a good surface roughness and flatness needed for a good contact with the cooling plate 27. The first side 17 of the insert 11 also needs to be machined after the bonding process. It is to achieve the required thermal gap for the thermal coupling element 12 as well as good flatness.

Advantages of the embodiments are that the thermal conductivity of copper is two times higher than aluminum which makes it a great heat spreading solution for PCB components having a high power concentration (high power and small surface area to remove the heat). The copper insert 11 is designed to be directly located over high power electronic components 6 on the PCB 5 to spread the heat across a bigger surface area. The higher surface area increases thermal transfer between the copper insert 11 and a passive and/or active cooling system.

Copper provides excellent thermal conductivity in all directions so heat spreading is not the only function of the hybrid housing 3. Another major advantage of the hybrid housing 3 is evacuating the heat from the electronic unit 4 by directly taking the heat from hot electronic components 6 on the PCB 5 through the thermal coupling element 12 and carrying the heat away by a natural or artificial airflow 25, 26, a standalone cooling plate and/or the cooling device 29.

Claims

1 . Vehicle module (1 ) with a housing (3) and an electronic unit (4) arranged in the housing (3), wherein the housing (3) comprises a housing part (10) with an opening (16) that is directly sealed with an insert (1 1 ) of the housing (3) by thermal bonding, wherein the housing part (10) is made of a first material with a first thermal conductivity and the insert (11 ) is made of a second material with a second thermal conductivity that is higher than the first thermal conductivity, wherein the insert (11 ) is configured to dissipate heat emitted by the electronic unit (4).

2. Vehicle module (1 ) according to claim 1 , wherein the insert (11 ) comprises a first side (17) facing an inside of the housing (3), wherein the first side (17) is thermally directly coupled to the electronic unit (4) by at least one thermal coupling element (12).

3. Vehicle module (1 ) according to any one of the preceding claims, wherein the electronic unit (4) comprises multiple heat emitting electronic components (6), which are in particular grouped together on the electronic unit (4), and multiple thermal coupling elements (12), wherein at least two of the multiple heat emitting electronic components (6) are thermally directly coupled to the first side (17) by spatially separated thermal coupling elements (12).

4. Vehicle module (1 ) according to claim 2 or 3, wherein the insert (1 1 ) comprises a base plate (19) with the first side (17) and an opposite second side (18) and at least one fin (20) extending from the base plate (19) at the second side (18).

5. Vehicle module (1 ) according to claim 4, wherein the vehicle module (1 ) comprises at least one fan (23) located adjacent to the at least one fin (20) so that an airflow (25, 26) generated by the at least one fan (23) is parallel to the at least one fin (20).

6. Vehicle module (1 ) according to claim 5, wherein the at least one fan (23) is located on an outer surface (24) of the housing part (10), in particular directly next to the at least one fin (20), wherein the outer surface (24) faces away from an inside of the housing (3).

7. Vehicle module (1 ) according to any one of the preceding claims, wherein the vehicle module (1 ) comprises a cooling plate (27) that is thermally directly coupled to the insert (1 1 ) by a thermal coupling element (12) on a second side (18) of the insert (11 ) facing away from an inside of the housing (3).

8. Vehicle module (1 ) according to any one of the preceding claims, wherein the insert (11 ) comprises at least a part of at least one cooling channel (28) of a cooling device (29) of the vehicle module (1 ).

9. Vehicle module (1 ) according to claim 8, wherein the insert (11 ) provides at least a part of a bottom part of the at least one cooling channel (28) and the housing (3) comprises a cover plate (30) attached to the housing part (10), wherein the cover plate (30) provides a top part of the at least one cooling channel (28) and covers the cooling device (29) towards an environment of the vehicle module (1 ).

10. Vehicle module (1 ) according to claim 8 or 9, wherein the insert (1 1 ) comprises a base plate (19) with a first side (17) facing an inside of the housing (3) and an opposite second side (18) facing the cover plate (30) and at least one thermal element (31 ) extending from the base plate (19) at the second side (18), wherein the at least one thermal element (31 ) is in particular at least one fin (20) and/or at least one pin and/or at least one turbulator.

11 . Vehicle module (1 ) according to any one of the preceding claims, wherein the first material is aluminum and/or the second material is copper and/or silver.

12. Vehicle (2) with a vehicle module (1 ) according to any one of the preceding claims.

13. Manufacturing method for a vehicle module (1 ) with a housing (3) and an electronic unit (4) arranged in the housing (3), wherein the housing (3) comprises a housing part (10) with an opening (16) and an insert (11 ), wherein the housing part (10) is made of a first material with a first thermal conductivity and the insert (1 1 ) is made of a second material with a second thermal conductivity that is higher than the first thermal conductivity, wherein the opening (16) in the housing part (10) is sealed with the insert (11) by thermal bonding, in particular at least partially by brazing, soldering and/or friction stir welding, wherein the insert (11) is configured to dissipate heat emitted by the electronic unit (4).

14. Manufacturing method according to claim 13, wherein the insert (11 ) is provided with a material allowance at least on a first side (17) facing an inside of the housing (3).

15. Manufacturing method according to claim 14, wherein at least the first side (17) and/or an opposite second side (18) of the insert (11 ) is machined after the thermal bonding so that a surface of the machined side has a roughness in a predefined roughness range and/or a flatness in a predefined flatness range.