Device for cooling an electronic component of a motor vehicle and method for assembling the device

Abstract

The invention relates to a device for cooling an electronic component (26) of a motor vehicle and a method for manufacturing it, the device comprising at least one thermally conductive element (14) for cooling an electronic component (26) arranged on a circuit board (16), comprising at least one housing part (18) with at least one opening (19) for connecting a heat sink, in particular a cooler ora cooling channel (13), wherein the heat-conducting element (14) is at least partially arranged in the opening (19) for the heat-conducting connection of the electronic component (26), wherein at least one fixing element (20) is provided on a side of the circuit board (12) opposite the electronic component (26), which is arranged on the circuit board (12) for stiffening it, wherein the fixing element (20) is fixed to the heat-conducting element (14) via a tolerance-compensating connection (25, 28, 30) for setting a desired minimum distance between the electronic component (26) and the heat-conducting element (14).

Description

The invention relates to a device for cooling an electronic component of a motor vehicle and a method for assembling the same according to the preamble of the independent claims. State of the art From DE 10 2013 206 999 A1, a control unit for a motor vehicle with a thermally conductive housing wall is known. The housing wall is formed from a thermally conductive sheet metal and acts as a heat sink. The thermally conductive housing wall is detachably connected to the housing and has an embossed feature in an area opposite the power semiconductor. This embossing brings the housing wall closer to the power semiconductor, such that the distance, in particular the gap, between the housing wall and the power semiconductor before embossing is greater than the distance, in particular the distance between the housing wall and the surface area, after embossing. The invention is based on the objective of ensuring reliable heat dissipation from the electronic component. This objective is achieved by the features of the independent claims. Disclosure of the invention By fixing the fixing element, which stiffens the circuit board (the one containing the electronic component to be cooled), to the thermally conductive element via a tolerance-compensating connection, the thermal contact resistance between the electronic component and the thermally conductive element can be minimized. After assembly and final fixing, the heat sink (the thermally conductive element) and the fixing element become integral parts of the circuit board. In this resulting assembly, all tolerances of the circuit board, the electronic component, and, if applicable, the thermally conductive element are compensated for. Subsequent stresses on the circuit board are minimized.Furthermore, manufacturing is simplified by pre-assembling the components into a single unit, which includes at least a fixing element, circuit board, electronic component, and thermally conductive element. This allows for adequate cooling of control units and vehicle computers with electronic components (SoC (System on Chip), microprocessors, microcontrollers, etc.) with high power dissipation or power density. The fixing element reduces circuit board deflection. Due to its robust design, this assembly can, for example, withstand the forces generated by a water cooling system. Because of the rigid fixation to the fixing element, these forces can be transferred back to the housing when properly connected. EMC shielding can also be achieved using conventional methods.Furthermore, multiple electronic components on a single circuit board can be reliably cooled without mutual mechanical interference. The circuit board can be fixed in place as usual, making it robust against vibrations and shocks, and subject to reduced mechanical stress thanks to the proposed cooling design. In a suitable further development, a tolerance-compensating connection is provided, in particular a sleeve-shaped receptacle on the heat-conducting element or on the fixing element, and a dome that can be fixed to the receptacle. This allows for the creation of an easily adjustable tolerance-compensating connection with simple means, which can be part of the fixing element and the heat-conducting element. In a practical further development, the dome is movable relative to the mount before the dome is fixed to the mount, in particular in the same direction as a surface of the electronic component relative to the heat-conducting element. This allows the desired minimum distance to be set using simple means. In a suitable further development, the tolerance-compensating connection comprises at least one fixing material, in particular an adhesive, most preferably an epoxy adhesive or epoxy resin, which is arranged between the receptacle and the dome. This allows the desired relative distance to be set for a certain time in the liquid or paste state, while after curing a particularly strong bond is formed between the fixing element and the heat-conducting element. In a suitable further development, the fixing element comprises at least one dome, in particular at least one opening, which projects further than the contact surface of the fixing element, especially through the printed circuit board (PCB). The dome is designed to form the tolerance-compensating connection with the thermally conductive element. This allows the PCB to act on the electronic component from the opposite side to adjust the desired minimum gap. Curing UV radiation, acting on the fixing material, can optionally be introduced through the opening. The fixing element can thus fulfill both the stiffening function for the PCB and the tolerance-compensating connection simultaneously, while being easy to manufacture. In a suitable further development, at least one connection, in particular a clamping device and / or at least a laser connection and / or at least an adhesive connection and / or at least an expansion dome, is provided for the permanent fixing of the tolerance-compensating connection. Depending on the application, manufacturing concept and geometry, different fixing methods can be selected. In a suitable further development, at least the fixing element and / or the circuit board is connected to the housing part, in particular to at least one protruding receptacle on the housing, via at least one fastening means. This allows forces generated, for example, by the cooling circuit, to be transferred back into the housing via the rigid assembly connected to the housing. This increases the robustness of the assembly. In a further advantageous embodiment, the fixing element comprises at least one, in particular rectangular, base body, and / or the fixing element comprises at least one arm projecting from a base body of the fixing element, and / or the fixing element comprises a frame enclosing the electronic component located on the opposite side of the printed circuit board, and / or the fixing element is made of metal, in particular aluminum, most preferably as an aluminum die-cast part, and / or the fixing element comprises at least one opening, in particular on the arm of the fixing element, for receiving at least one fastening element. This allows the fixing element to perform a wide variety of functions. Furthermore, the strength of the connection between the fixing element and the thermally conductive element can be increased, especially if both elements are made of metal. In a suitable further development, it is provided that the thermally conductive element includes at least one contact surface for the electronic component to set the desired minimum distance and / or that the thermally conductive element includes at least one contact surface for thermal connection to the electronic component via at least one further thermally conductive element and / or that the thermally conductive element includes at least one overflow zone adjoining laterally from the connection surface to accommodate a further thermally conductive element displaced by the electronic component and / or that the thermally conductive element includes at least one receptacle for the passage of at least one fastening element and / or at least one receptacle in the housing and / or that the thermally conductive element includes at least one further heat dissipation area for thermal connection to at least one further electronic component and / or that the thermally conductive element includes at least one in aThe cooling channel incorporates a surface structure for heat dissipation. This allows for relatively accurate and precise adjustment of the desired minimum gap during manufacturing. Ensuring the drainage of excess heat-conducting material from the connection zone also contributes to reliably setting the desired minimum gap. Appropriate fixtures facilitate the correct positioning of the fixing element relative to the heat-conducting element. By providing additional heat dissipation areas, multiple electronic components can be cooled via a single heat-conducting element. The appropriate surface structure improves the thermal resistance to the cooling channel or cooler. In a suitable further development, at least one receptacle for a seal is provided in the housing part and / or the heat-conducting element. This allows for a reliable and tolerance-compensating seal against a cooling channel transporting a cooling medium, particularly in the housing part. In a suitable further development, another thermally conductive element, in particular a flexible thermally conductive element or thermal paste, etc., is provided between the thermally conductive element and the electronic component. This allows the heat transfer to be further improved, especially due to the good adaptation of the additional thermally conductive element to the surface of the electronic component caused by its flexibility. Furthermore, a method according to the invention is provided in accordance with the features of the further independent claim, which contributes to a simplified and reliable assembly of the device. Further appropriate training courses result from other dependent requirements and from the description. Brief description of the drawing Figure 1 shows a schematic representation of the device for cooling an electronic component in an exploded view, Figure 2 shows a section through one side of a pre-assembled assembly of the device, Figure 3 shows a perspective view of the heat-conducting element with an enlarged representation in the contact area of ​​the electronic component, Figure 4 shows a section through the assembled device for cooling, and Figure 5 shows different fixing variants for forming an assembly. embodiment of the invention The invention is schematically illustrated using an exemplary embodiment and is described in detail below with reference to the drawing. Fig. 1 shows an exploded view of a schematically represented device for cooling an electronic component 26 of a motor vehicle as part of a control unit 10. The control unit 10 comprises at least one printed circuit board 16 on which at least the electronic component 26 to be cooled is arranged. The electronic component 26 can be, for example, a so-called SIP (System-In-Place) or a component thereof and / or a so-called System-On-Chip (SoC), microcontroller, microprocessor, or other semiconductor or chip with high power dissipation. Further electronic components 56 to be cooled can also be provided on the printed circuit board 16, as shown by way of example in Fig. 2. A fixing element 20 is arranged on the side of the printed circuit board 16 opposite the electronic component 26. The fixing element 20 comprises at least one base body 33, which is preferably frame-shaped. Several contact surfaces 35 are formed on the base body 33 and project towards the surface of the printed circuit board 16. When the fixing element 20 is mounted, these contact surfaces 35 are in contact with the side of the printed circuit board 16 opposite the electronic component 26. The size of the base body 33 is approximately based on the dimensions of the electronic component 26 to be cooled. Preferably, the base body 33 surrounds the electronic component 26 arranged opposite it. The fixing element 20 comprises arms 21 projecting from each corner opposite the base body 33. Each arm 21 has an opening 22 for receiving at least one fastening element 23. The fastening element 23 is, for example, designed as a screw. The opening 22 on the fixing element 20 is preferably designed to include a mating surface, for example for a screw head, as shown in more detail in Fig. 2. The opening 22 on the fixing element 20 aligns with a corresponding opening 27 in the circuit board 16, as well as with corresponding receptacles 32 on a housing or housing part 18, and optionally with recesses 55 in the heat-conducting element 14. The receptacles 32 on the housing part 18 project dome-like beyond the surface of the housing part 18.The fixing element 20, together with the circuit board 16 and a thermally conductive element 14 connected to it to form an assembly 48, can be fastened to the housing part 18 via the fastening means 23, preferably by screwing. The fixing element 20 comprises at least one component of a tolerance-compensating connection 25, 28, 30. The tolerance-compensating connection 25, 28, 30 serves to permanently fasten the fixing element 20 together with the printed circuit board 16 and the electronic component 26 arranged thereon, together with the thermally conductive element 14, to form an assembly 48. This fastening using the tolerance-compensating connection 25, 28, 30 is to be carried out in such a way that a desired minimal gap is established between the surface of the electronic component 26 and the surface of the thermally conductive element 14, hereinafter referred to as the contact surface 51, which is oriented towards the surface of the electronic component 26. In the exemplary embodiment, the tolerance-compensating connection 25, 28, 30 comprises at least one receptacle 30. In this embodiment, the receptacle 30 is part of the thermally conductive element 14. Alternatively, the receptacle 30 could also be part of the fixing element 20, while the corresponding counterpart, such as the dome 25, could also be part of the thermally conductive element 14. Since different geometric tolerances and designs may be present, the tolerance-compensating connection 25, 28, 30 serves to individually adapt the fixing (of the thermally conductive element 14 to the populated circuit board 16 with fixing element 20) to the respective geometric conditions in order to achieve a desired minimum gap dimension. In the embodiment shown in Fig. 1, at least one dome 25 is provided as part of the tolerance-compensating connection 25, 28, 30 on the fixing element 20. The dome 25 projects further beyond the contact surface 35 (which, in the assembled state, is in direct contact with the surface of the printed circuit board 16). In this embodiment, the dome 25 projects through the printed circuit board 16. A corresponding recess 29 is provided in the printed circuit board 16 for this purpose; this recess is, for example, circular and corresponds to the outer contour of the dome 25. The dome 25 is preferably cylindrical. The dome 25 is arranged at the corners of the rectangular or frame-shaped base body 33 of the fixing element 20. The fixing element 20 consists of a rigid material. With regard to the tolerance-compensating connection 25, 28, 30 of the fixing element 20 with the heat-conducting element 14 (which, as described below, is particularly preferably made of metal), a metal is especially suitable for this purpose. Preferably, the fixing element 20 is designed as an aluminum part. It can, for example, be manufactured as a die-cast part. The dome 25, in turn, is at least partially surrounded by the receptacle 30 when assembled. The receptacle 30 is, for example, sleeve-shaped. Furthermore, the receptacle 30 allows the dome 25 to be inserted to varying degrees depending on the minimum gap to be set. The receptacle 30 is, for example, conical. This partially inclined or conical design of the receptacle 30 could be particularly suitable with regard to the coefficient of thermal expansion of a fixing material 28, so that, depending on the material, expansion does not lead to high undesirable forces. A corresponding inclination could prevent this. The fixing material 28 is located in the receptacle 30 to secure the receptacle 30 with the dome 25 in the desired position, which was chosen to minimize the gap between the electronic component 26 and the thermally conductive element 14. The fixing material 28 is arranged in the gap between the end of the dome 25 that enters the receptacle 30 and the area of ​​the receptacle 30 surrounding this end of the dome 25. The fixing material 28 can be an adhesive, preferably a liquid or pasty adhesive that subsequently hardens and is characterized by high strength after hardening. The fixing material 28 is designed such that it can be displaced when the dome 25 is inserted into the receptacle 30. For this purpose, an overflow zone 52 (see Fig. 3) is provided in the thermally conductive element 14, as shown later, which serves to receive the displaced fixing material 28.An epoxy adhesive is particularly preferred. This can be cured, for example, by UV light. For improved UV curing, UV radiation 60 can act on the fastener 28 from above through an optional opening 58 in the dome 25, as indicated, for example, in Fig. 2. However, other liquid fixing materials 28 that cure in the desired position can also be used. The tolerance-compensating connection 25, 28, 30 could, however, also be designed differently; in the simplest case, a surface on the fixing element 20 and a corresponding mating surface on the heat-conducting element 14 would be provided, allowing a certain relative movement between the fixing element 20 and the heat-conducting element 14 in order to minimize the gap. The surface and mating surface must, however, be arranged directly adjacent to each other across the relevant tolerance range, so that appropriate fixing via possible fixing means 40, 42, 44, 46 (see Fig. 5) is enabled at the desired location, guaranteeing a minimal gap dimension. A thermally conductive element 14 is provided for the heat dissipation of the electronic component 26 by means of a heat sink such as a cooler 12 or a cooling channel 13 of a cooler 12. The thermally conductive element 14 is in thermal contact with the electronic component 26 to be cooled. The contact surface 51 of the thermally conductive element 14, oriented towards the electronic component 26, completely covers the surface of the electronic component 26. To adjust the desired minimum gap dimension, the thermally conductive element 14 comprises several contact surfaces 50. In the exemplary embodiment, three contact surfaces 50 are provided. These relatively small contact surfaces 50 protrude from the surface of the contact surface 51 by the amount of the desired gap dimension.The desired gap dimension can be selected, for example, in the range of 0.2 mm ± 0.05 mm, depending on the additional thermally conductive material 15 provided between the connection surface 51 and the surface of the electronic component 26. In this example, the contact surfaces 50 protrude approximately 0.2 mm beyond the connection surface 51. During assembly, the electronic component 26 is indirectly pressed against these contact surfaces 50 by force or displacement control and held in this desired position until the tolerance-compensating connection 25, 28, 30 has permanently joined the thermally conductive element 14 with the populated circuit board 16 and the fixing element 20 to form an assembly 48. To improve heat transfer, an additional thermally conductive element 15 is provided between the electronic component 26 to be cooled and the surface of the thermally conductive element 14. This element 15 can be, for example, a flexible material such as a cushion or pad. Other TIM materials (TIM: thermal interface materials or thermally conductive material 28; for example, thermally conductive pastes, thermally conductive adhesives, etc.) can also be used. This additional thermally conductive element 15 can, for example, be applied in a meandering pattern to the thermally conductive element 14, with the surface of the electronic component 26 to be cooled then pressing against it and, if necessary, displacing the additional thermally conductive element 15 accordingly.This completely fills the gap between the surface of the thermally conductive element 14 and the surface of the electronic component 26 to be cooled with the additional thermally conductive element 15, ensuring optimal thermal connection of the electronic component 26 to the thermally conductive element 14. Figure 3 shows a perspective view of the heat-conducting element 14 in more detail. The three contact surfaces 50 are visible. Two of the contact surfaces 50 are located in the corner areas of the electronic component 26 that will later be placed on them. These two contact surfaces 50 border the receptacles 30 on one side and each extend rectangularly towards the connection surface 51. During assembly, the additional, preferably liquid or pasty, heat-conducting element 15 is applied to this connection surface 51. Overflow zones 52 border these connection surfaces 51 laterally. The overflow zones 52 are designed as flat surfaces. These overflow zones 52 are located lower than the connection surface 51. If the electronic component 26 is now placed on the respective support surfaces 50, the surface of the electronic component 26 displaces the already applied further heat-conducting element 15 into the lower overflow zones 52.This ensures that the desired minimum gap between the connection surface 51 and the surface of the electronic component 26 to be cooled, defined by the contact surfaces 50, can be reliably achieved. The right-hand sectional view of Fig. 3 shows the electronic component 26 resting on the contact surface 50 with its associated circuit board 16. In this view, the stepped connection of the lower overflow zone 52 is clearly visible. The thermally conductive element 14 according to Fig. 3 is further characterized by additional heat dissipation areas 54. These additional heat dissipation areas 54 of the thermally conductive element 14 serve to dissipate heat from the additional electronic components 56. The height of the associated heat dissipation areas 54 varies depending on the geometry of the additional electronic components 56. It is essential that this does not impede the adjustment of the minimum gap dimension between the electronic component 26 and the connection surface 51. For thermal connection, the additional thermally conductive element 15 is also introduced between the respective heat dissipation areas 54 and the surfaces of the additional electronic components 56 (see also Fig. 2). The heat-conducting element 14 preferably includes corresponding recesses 30 in each corner region, which interact with corresponding domes 25 of the fixing element 20 to form a tolerance-compensating connection. In the embodiment according to Fig. 3, the heat-conducting element 14 includes at least one recess 55. Preferably, a recess 55 is provided at each corner of the rectangular heat-conducting element 14. The recess 55 is circular. The fastening element 23 and / or the receptacle 32 can be guided through the recess 55 in the housing 18. This allows for improved fixation. The heat-conducting element 14 can be a so-called heat spreader, a particularly heat-conducting material such as a metal, especially copper or similar, or a so-called vapor chamber, in which the heat generated is dissipated particularly effectively via a phase change of a cooling medium arranged in a closed cavity. To improve heat transfer to the cooler 12, the heat-conducting element 14 has certain surface structures 17, such as ribs, projections, or pins, or turbulators (for example, in the form of appropriately shaped sheets), to increase the surface area of ​​the heat-conducting element 14 for better heat dissipation. These surface structures 17 are surrounded by a cooling medium from the cooler 12 in a cooling channel 13 (see Fig. 4) for heat dissipation.The cooling medium can be a liquid, such as water or a water-glycol mixture, or similar, or a gaseous or other cooling medium, such as air, etc. Due to the high heat dissipation of the electronic component 26, a cooler 12 operating with a liquid cooling medium, in particular a water cooler, is used. The cooler 12 has a coolant supply and a coolant outlet for circulating the coolant. The corresponding cooling channels 13 for circulating the coolant can be integrated into the housing part 18 or the housing 18. The coolant supply and outlet are not shown separately in Fig. 1. Fig. 4 shows the assembly 48 mounted in the housing 18 or housing part. The housing 18, which at least partially forms the cooling channel 13, has an opening 21 that serves to receive the heat-conducting element 14, or in particular its surface structure 17. This opening 21 is part of the cooling channel 13 through which the cooling medium flows. During the assembly of the control unit 10, a flexible and permanently elastic seal 24 (for example, in the form of an O-ring) is applied around this opening 21 in a recess 31 surrounding the opening 21, so that a gap between the housing 18 and the heat-conducting element 14 is sealed against the cooling medium of the cooling channel 13. Alternatively, the seal 14 can be applied by adhesive bonding and cured after the assembly 48 has been mounted in the housing 18. This can serve to further compensate for tolerances. Due to the rigid connection between the fixing element 20, the circuit board 16, and the housing 18, the forces arising from the water circuit can be absorbed. The water presses against the heat-conducting element 14. The heat-conducting element 14, in turn, presses against it with the help of the very rigid fixing element 20. The fixing element 20 transmits the forces back into the housing 18 via the rigid screw connection (fastener 23 screwed into the receptacles 32 in the housing 18). Fig. 5 shows different ways in which the tolerance-compensating connection 25, 28, 30 can be fixed after the desired minimum gap dimension has been set. In the upper figure, a clamping device 40 is provided for fixing. For example, a clamping screw guided through the side walls of the receptacle 30 presses against the side wall of the dome 25. This prevents relative movement between the receptacle 30 and the dome 25. In the second figure, the materials of the dome 25 and the receptacle 30 are welded together by the input of energy, for example in the form of a laser 42 or similar device. Other suitable material-bonding methods can also be used alternatively. The variant in the third figure relates to the one already described with the fixing material 28. This is an adhesive bond 44. The lower illustration relates to an expanding dome 46.For example, by spreading the spreader dome 46 accordingly, the dome 25 could be pressed against the receptacle 30 and thereby fixed in place. Other fixation methods are also possible. The following briefly describes the assembly steps of a method for manufacturing the device for cooling an electronic component 26 of a motor vehicle. First, the additional heat-conducting element 15, which is in liquid or paste form, is applied or dispensed onto the connection surface 51 of the heat-conducting element 14. The application could, for example, be in a meandering pattern. The additional heat-conducting element 15 is also applied to the further cooling areas 54 of the heat-conducting element 14. In parallel or subsequently, the fixing material 28, preferably liquid adhesive, is placed into the receptacles 30. In a further step, the fixative material 28 can be pretreated, for example by applying UV radiation 60. In the next step, the fixing element 20, the circuit board 16 (equipped with at least the electronic component 26), and the thermally conductive element 14 are assembled to form a module 48. For this purpose, the domes 25 are inserted through the recesses 29 of the circuit board 16. This connects the circuit board 16 and the fixing element 20. Subsequently or concurrently, the electronic component 26 is positioned on the contact surfaces 50 of the thermally conductive element 14. This is achieved through force- and / or displacement-controlled assembly. First, the circuit board 16 is pressed down with a controlled force, for example, less than 150 N. As soon as the force exceeds a certain limit, for example, greater than 300 N, it is assumed that the electronic component 26 has reached the contact surfaces 50. Then, further pressure on the circuit board 16 or the electronic component 26 is stopped. The position thus achieved (of the electronic component 26 relative to the thermally conductive element 14) is then held in a controlled manner. The tolerance-compensating connection 25, 28, 30 is fixed in this desired position. For example, the fixing material 28 could be further cured using UV radiation 60. Alternatively, the pre-assembled component 48, thus fixed, could be stored until the fixing material 28 has cured. A suitable fixing method according to the alternatives shown in Fig. 5 (clamping 40, laser 42, gluing 44, spreading the expansion dome 46, or similar) could also be used. Subsequently, the appropriate fasteners and the seal 24 can be applied to the housing 18. The assembly 48 is then placed on the housing 18 and screwed into the respective receptacles 32 on the housing 18 using the appropriate fasteners 23, which are inserted into the openings 21 on the fixing element 20 through the openings 27 on the circuit board 16, thus securing it. In a further step, the fasteners (between the housing 18 and the assembly 48) and, if applicable, the seal 24 can be cured, for example by applying heat, etc. The electronic components 26 comprise, in particular, high-performance computing cores that perform especially computationally intensive functions in the vehicle. These can include, for example, autonomous or semi-autonomous driving functions, infotainment, communication interfaces between different bus systems (Ethernet, CAN, LIN, etc.) or gateway functionalities, certain security applications for granting authorization, for example, to access the vehicle remotely, or other operations in the vehicle that require particularly high computing power. The electronic components 26 are preferably high-performance microcontrollers, processors, multi-core processors, or highly integrated circuits (SoC, System-on-Chip) characterized by high power dissipation. For reasons of reliability, a particularly dependable and robust heat dissipation system, adapted to the application in the vehicle, is provided. QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature DE 10 2013 206 999 A1

[0002]

Claims

Device for cooling an electronic component (26) of a motor vehicle, comprising at least one thermally conductive element (14) for cooling an electronic component (26) arranged on a printed circuit board (16), comprising at least one housing part (18) with at least one opening (19) for connecting a heat sink, in particular a cooler or a cooling channel (13), wherein the thermally conductive element (14) is at least partially arranged in the opening (19) for the thermally conductive connection of the electronic component (26), wherein at least one fixing element (20) is provided on a side of the printed circuit board (12) opposite the electronic component (26), which is arranged on the printed circuit board (12) for stiffening it, wherein the fixing element (20) is fixed to the thermally conductive element (14) via a tolerance-compensating connection (25, 28, 30) for setting a desired minimum distance between the electronic component (26) and the thermally conductive element (14). Device according to claim 1 characterized in that a, in particular sleeve-shaped, receptacle (30) on the heat-conducting element (14) or on the fixing element (20) and a dome (25) that can be fixed with the receptacle (30) are provided as a tolerance-compensating connection (25, 28, 30). Device according to one of the preceding claims, characterized in that the dome (25) is movable relative to the receptacle (30) prior to fixing the dome (25) with the receptacle (30), in particular in the same direction as a surface of the electronic component (26) relative to the heat-conducting element (14). Device according to one of the preceding claims, characterized in that the tolerance-compensating connection (25, 28, 30) comprises at least one fixing material (28), in particular an adhesive, especially preferably an epoxy adhesive or epoxy resin, which is arranged between the receptacle (30) and the dome (25). Device according to one of the preceding claims, characterized in that the fixing element (20) comprises at least one dome (25), in particular at least one opening (58), which extends further than the contact surface (35) of the fixing element (20), in particular through the circuit board (16), wherein the dome (25) is configured to enter into the tolerance-compensating connection (25, 28, 30) with the heat-conducting element (14). Device according to one of the preceding claims, characterized in that at least one connection (40, 42, 44, 46), in particular a clamping means (40) and / or at least a laser connection (42) and / or at least an adhesive connection (44) and / or at least a spreading dome (46), is provided for permanently fixing the tolerance-compensating connection (25, 28, 30). Device according to one of the preceding claims, characterized in that at least the fixing element (20) and / or the circuit board (16) is connected to the housing part (18), in particular to at least one projecting receptacle (32) on the housing part (18), via at least one fastening means (23). Device according to one of the preceding claims, characterized in that the fixing element (20) comprises at least one, in particular rectangular, base body (33) and / or that the fixing element (20) comprises at least one arm (21) projecting from a base body (33) of the fixing element (20) and / or that the fixing element (20) comprises a frame enclosing the electronic component (26) located on the opposite side of the circuit board (16) and / or that the fixing element (20) is made of metal, in particular of aluminum, particularly preferably as an aluminum die-cast part, and / or that the fixing element (20) comprises at least one opening (22), in particular on the arm (21) of the fixing element (20), for receiving at least one fastening means (23). Device according to one of the preceding claims, characterized in that the thermally conductive element (14) comprises at least one contact surface (50) for the electronic component (26) for adjusting the desired minimum distance and / or that the thermally conductive element (14) comprises at least one contact surface (51) for thermal connection to the electronic component (26) via at least one further thermally conductive element (15) and / or that the thermally conductive element (14) comprises at least one overflow zone (52) adjoining laterally from the connection surface (51) for receiving a further thermally conductive element (15) displaced by the electronic component (26) and / or that the thermally conductive element (14) comprises at least one receptacle (55) for the passage of at least one fastening element (23) and / or at least one receptacle (32) in the housing (18) and / or that the thermally conductive element (14) comprises at least one further heat dissipation area (54) for thermal connection toat least one further electronic component (56) and / or that the heat-conducting element (14) includes at least one surface structure (17) projecting into a cooling channel (13) for heat dissipation. Device according to one of the preceding claims, characterized in that at least one receptacle (31) for a seal (24) is provided in the housing part (18) and / or the heat-conducting element (14) and / or that a cooling channel (13) is provided in the housing part (18). Method for assembling a device for cooling an electronic component (26) of a motor vehicle, particularly according to claim 1, wherein at least one heat-conducting element (14) is provided for cooling an electronic component (26) arranged on a printed circuit board (16), wherein at least one fixing element (20) is provided on a side of the printed circuit board (12) opposite the electronic component (22), which is arranged on the printed circuit board (12) for stiffening it, wherein the fixing element (20) is fixed to the heat-conducting element (14) via a tolerance-compensating connection (25, 28, 30) to set a desired minimum distance between the electronic component (26) and the heat-conducting element (14), wherein the heat-conducting element (14) is arranged at least partially in an opening (19) of a housing (18) or housing part (18). Method according to the preceding method claim, characterized in that at least one further heat-conducting element (15) is applied to a bonding surface (51) of the heat-conducting element (14), on which the electronic component (26) is subsequently placed. Method according to one of the preceding method claims, characterized in that at least one dome (25) of the fixing element (20) or of the heat-conducting element (14) is brought into a receptacle (25), wherein dome (20) and receptacle (25) are components of the tolerance-compensating connection (25, 28, 30), wherein a relative movement between dome (25) and receptacle (25) takes place until the desired minimum distance between the electronic component (26) and the heat-conducting element (14) is established by permanently fixing the dome (25) with the receptacle (30). Method according to one of the preceding method claims, characterized in that at least one fixing material (28), in particular a liquid adhesive, is applied and cured as part of the tolerance-compensating connection (25, 28, 30), in particular by UV radiation (60), when the desired minimum distance between the electronic component (26) and the heat-conducting element (14) is established. Method according to one of the preceding method claims, characterized in that the electronic component (26) is positioned on contact surfaces (50) of the heat-conducting element (14) and / or that the electronic component (26) is pressed against the heat-conducting element (14) or onto its contact surfaces (50) with a certain force until the force reaches a certain limit at which the desired minimum gap dimension is achieved. Method according to one of the preceding method claims, characterized in that an assembly (48) comprising at least the fixing element (20), the circuit board (16) with electronic component (26) and thermally conductive element (14) is connected to the housing (18) and / or that at least one seal (24) is applied between an assembly (48) comprising at least the fixing element (20), the circuit board (16) with electronic component (26) and thermally conductive element (14) and the housing (18).

Images