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

Abstract

A device for cooling an electronic component (22) of a motor vehicle and a method for assembling the same are proposed, wherein the device comprises at least a printed circuit board (12), at least one electronic component (22) to be cooled arranged on the printed circuit board (12), at least one cooler (16) for cooling the electronic component (22), at least one thermally conductive element (24) arranged between the electronic component (22) and the cooler (16), and at least one housing (11) which at least partially encloses the printed circuit board (12), wherein at least one stiffening element (14) is provided on the side of the printed circuit board (12) opposite the side on which the electronic component (22) is arranged, and which is arranged on the printed circuit board (12) for stiffening it, wherein at least one resilient fastening (18,20) is provided for fixing the stiffening element (14) together with the circuit board (12) to the cooler (16) and / or to the housing (11), wherein the spring fastening (18, 20) acts on the stiffening element (14).

Description

[0001] 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

[0002] A power electronics arrangement is known from DE 202009018077 U1. A pin with spring elements is secured on one side of the heat sink facing away from the printed circuit board. The longitudinal axis of the pin runs perpendicular to the plane of the printed circuit board. Due to the central arrangement of the mounting device, the SMD components are pressed evenly against the first layer, thus achieving a uniform cooling effect.

[0003] The object of the present invention is to further increase the reliability of a control unit, particularly in the automotive sector with its high loads. This object is achieved by the features of the independent claims. Disclosure of the invention

[0004] By providing at least one stiffening element on the side of the circuit board opposite the electronic component, and by including at least one spring-loaded fastening to fix the stiffening element together with the circuit board to the heat sink and / or the housing, with the spring-loaded fastening acting on the stiffening element, the stability and thus the reliability of the device can be further increased. Furthermore, the nominal gap (between the electronic component and the heat sink) as well as the tolerance band within which the gap can lie can be significantly reduced. This considerably improves the heat dissipation of relevant components. Additionally, it is possible to use other materials such as flexible thermally conductive elements, designed, for example, as cushions or pads. This allows the thermal resistance to be reduced even further.Production costs can also be reduced, if necessary, by using a more easily processed heat-conducting element.

[0005] In a suitable further development, the spring-loaded mounting is designed so that the electronic component experiences a force in the direction of the cooler. This further improves heat transfer.

[0006] In a suitable further development, the stiffening element includes at least one receptacle, in particular a sleeve-shaped one, and / or the circuit board includes at least one opening for receiving the spring-loaded fastener. This allows the circuit board, together with the stiffening element, to be mounted to the cooler or the housing using a small number of fasteners.

[0007] In a suitable further development, the cooler and / or the housing includes at least one receptacle for receiving the spring-loaded mounting. This further increases the stability of the assembly, as the circuit board can be mounted directly to the cooler or housing.

[0008] In a further advantageous embodiment, the resilient fastening comprises at least one fastening element, in particular a screw, and a spring, wherein the spring is arranged between a mating surface on the fastening element, in particular a screw head, and the surface of the stiffening element. This type of fastening protects the printed circuit board against direct force exerted by the fastening element and further increases its stability.

[0009] In a further advantageous embodiment, the stiffening element comprises at least one, in particular rectangular, base body and / or at least one arm projecting from a base body of the stiffening element. The frame can be easily adapted to the geometry of the area of ​​the printed circuit board to be stiffened, where the electronic component to be cooled is located. Preferably, the arm or the base body accommodates the spring-loaded mounting. A receptacle on the arm of the stiffening element preferably aligns with a corresponding receptacle on the heat sink, which is preferably located in the area that does not cover the surface of the electronic component to be cooled. This further increases stability.

[0010] In a further development, it is provided that the cooler completely covers the surface of the electronic component to be cooled, and the mounting point on the cooler is located outside the area covering the surface to be cooled. This allows for particularly effective cooling of the electronic component's surface, as the entire surface is directed to the cooler via the heat-conducting element.

[0011] A particularly advantageous feature is the inclusion of at least one additional electronic component, positioned adjacent to the cooler for heat dissipation. This heat dissipation concept is especially suitable for the often redundant processors used as potential electronic components, such as those found in autonomous driving applications.

[0012] The invention further relates to a method for mounting a device for cooling an electronic component in a motor vehicle according to the features of the independent method claim. This allows for a particularly simple and safe manufacturing process that minimizes the gap between the electronic component and the cooler by applying a corresponding force to the circuit board until the spring-loaded mounting is in the desired final position. This ensures that the electronic component remains in the desired position relative to the cooler until the assembly is complete.

[0013] Further advantages and embodiments of the invention will become apparent from further dependent claims, from the description and the drawing. Brief description of the drawings

[0014] They show: Fig. 1 schematically a side view of the device, Fig. 2 a view of the underside of the circuit board as well as Fig. 3a - 3d different steps for assembling the device. Embodiments of the invention

[0015] The invention is schematically illustrated in the drawing using one embodiment and is described in more detail below.

[0016] Fig. Figure 1 shows a control unit 10, which comprises at least one printed circuit board 12 with at least one electronic component 22. The electronic component 22 is electrically connected to the printed circuit board 12 via corresponding contacts 23. The control unit 10 comprises at least one heat sink 16. The heat sink 16 is thermally connected to the electronic component 22, which is to be cooled, via a thermally conductive element 24.

[0017] The thermally conductive element 24 essentially corresponds to the size of the surface of the electronic component 22 facing the cooler 16. The thermally conductive element 24 can, for example, be a thermally conductive material that fills the gap between the surface of the electronic component 22 and the cooler 16 (a so-called TIM, Thermal Interface Material). The thermally conductive element 24 could also be a flexible, compressible material, such as a gap-filling cushion or pad. The thickness of the so-called TIM gap must be selected so that even in the narrowest possible case, the gap is not compressed. The thermally conductive element 24 serves to displace the air between the electronic component 22 and the cooler 16, thereby improving heat transfer.

[0018] Warping of the circuit board 12 can be reduced or prevented by a stiffening element 14. The stiffening element 14 is designed, for example, as a stiffening frame. For this purpose, the stiffening element 14 comprises, for example, a rectangular frame with arms 15 projecting outwards at each corner, as shown in Fig. Figure 2 shows the top view from below in more detail. The stiffening element 14 is arranged in the area of ​​the electronic component 22 to be cooled, on the side of the circuit board 12 opposite the electronic component 22. Especially when using the spring-loaded fasteners 18, 20, which reduce the TIM gap, the stiffening element 14 prevents impermissible deflection of the circuit board 12. Furthermore, this allows the tightening forces to be distributed evenly. In the exemplary embodiment according to Fig. Figure 2 shows four screw points for the spring-loaded mounting 18, 20. The frame improves the stability of the circuit board, especially in the area of ​​the electronic component 22, while the arms 15 projecting outwards from the frame enable the circuit board 12 to be attached to the cooler 16 outside of the electronic component 22.

[0019] The circuit board 12, together with the stiffening element 14, is connected to the cooler 16 and / or to a housing 11 by spring-loaded fasteners 18, 20. The spring-loaded fasteners 18, 20 can be designed as fasteners 18, such as screws or similar components, and springs 20. In the exemplary embodiment, the springs 18 surrounding the respective screws are arranged between the screw heads and the stiffening element 14. When the spring-loaded fastener 18, 20 is screwed into the respective receptacle 19 on the cooler 16, the spring 20, compressed by the screwing action, exerts a corresponding pressure on the stiffening element 14, which in turn presses the circuit board 12, together with the electronic component 22 to be cooled, against the cooler 16 or against the heat-conducting element 24 on the cooler 16. This closes the corresponding gap or...TIM gap between the surface of the electronic component 22 and the surface of the cooler 16 minimized.

[0020] The fastening elements 18 each protrude through corresponding receptacles 13 of the stiffening element 14 and corresponding openings 28 in the circuit board 12 and are aligned with the corresponding receptacles 19 on the cooler 16, which may be threaded, for example. The receptacles 13 of the stiffening element 14 can be corresponding recesses in the stiffening element 14 that are oriented to the outer contour of the fastening element 18. The receptacles 13 can also be sleeve-shaped, for example, as shown in Fig. 3c or Fig. 3D indicated. These sleeve-shaped receptacles 13 can be designed to protrude through corresponding openings 28 in the circuit board 12.

[0021] Alternatively, the mounting 19 could also be part of the housing 11, which at least partially encloses the circuit board 12 and the electronic component 22 to be cooled on it. Alternatively, the cooler 16 could be an integral part of the housing 11.

[0022] In the exemplary embodiment, the cooler 16 comprises at least one cooling channel 30 filled with a thermally conductive material such as water or similar. Alternatively, the cooling channel 30 could be omitted if the heat is dissipated directly to the environment, for example, via appropriate cooling fins or enlarged surface areas. The appropriate cooler 16 must be selected according to the heat to be dissipated. The cooler 16 is larger than the surface area of ​​the electronic component 22 to be cooled. This allows the circuit board 12, with the electronic component 22 to be cooled, to be connected laterally to the cooler 16 by means of the spring-loaded fasteners 18, 20. The cooler 16 extends beyond the surface area of ​​the electronic component 22.

[0023] Further electronic components 22 could be arranged on the circuit board 12, which are thermally connected to the cooler 16 for heat dissipation via corresponding thermally conductive elements 24. The multiple electronic components 22 are, in turn, arranged within the effective area of ​​the stiffening element 14 so that bending of the circuit board 12 is prevented as far as possible during the spring-loaded fastening 18, 20 and when the multiple electronic components 22 are pressed against the cooler 16. Here, too, the circuit board 12 is screwed to the cooler 16 or to the housing 11. The cooler 16 covers all surfaces of the electronic components 22 to be cooled. The described device is particularly suitable for one or two electronic components 22 requiring cooling, such as those used, for example, in control units 10 for high-performance computer systems, such as those used for autonomous driving or similar applications.Often, suitable processors or microcontrollers can be built redundantly as possible electronic components 22, making the device particularly suitable for this purpose.

[0024] In Fig. 3 are the various assembly steps for mounting the device or control unit 10 according to Fig. 1 shown. In one step 101 ( Fig. 3a) The cooler 16 or the housing 11 is positioned. The cooler 16 is arranged so that the receptacles 19 for receiving the spring-loaded mounting 18, 20 are oriented upwards.

[0025] In one step 102 ( Fig. 3b) The thermally conductive material 24 is positioned on the cooler 16 or on the housing 11. For example, a flexible cushion or pad could be placed accordingly. If the material is initially liquid and then hardens, the thermally conductive element 24 could be dispensed onto the cooler 16. The thermally conductive element 24 is positioned between the two receptacles 19. This allows the spring-loaded fastening 18, 20 of the circuit board 12 to the cooler to be located outside the surface of the electronic component 22 to be cooled.

[0026] In one step 103 ( Fig. 3c) The circuit board 12 with the mounted electronic components 22 and the stiffening element 14, which is arranged on the side of the circuit board 12 opposite the electronic component 22, is placed. The circuit board 12 is oriented so that the electronic component 22, with the surface to be cooled, faces the heat-conducting element 24 or the cooler 16. (See sectional view according to...) Fig.Figure 3c shows that the stiffening element 14 has sleeve-shaped receptacles 13 for the respective fastening means 18. The sleeve-shaped receptacles 13 project into the corresponding openings 28 of the printed circuit board 12. This ensures precise positioning of the stiffening element 14 relative to the openings 28 in the printed circuit board 12. Furthermore, the printed circuit board 12 is arranged such that the corresponding openings 28 are aligned with the associated receptacles 19 on the cooler 16 or housing 11 to accommodate the respective fastening means 18.

[0027] In step 104, the circuit board 12 is held down, as indicated by the application of a corresponding force, symbolized by arrow 32. This holds or presses the stiffening frame 14, together with the circuit board 12 and the electronic component 22, against the surface of the heat-conducting element 24 located on the cooler 16 or the housing 11. Subsequently or concurrently, the spring-loaded fastening 18, 20 is carried out, for example, using spring-loaded screws. This presses the circuit board 12 or the electronic component 22 to be cooled against the cooler 16 or the heat-conducting element 24 by the springs 20. The stiffening element 14 prevents further deflection of the circuit board 12.

[0028] The control unit 10 is used in the automotive sector. It is characterized by its exceptional moisture resistance and robust construction. Consequently, the control unit 10 is subjected to relatively high mechanical loads. The provision of the stiffening element 14 in conjunction with the spring-loaded mounting 18, 20 stabilizes the circuit board 12. Furthermore, the nominal TIM gap, as well as the tolerance band within which the gap can operate, can be significantly reduced. This considerably improves the heat dissipation of relevant components or electronic parts 22. As a result, other thermally conductive elements 24, as specified above, can also be used, which further reduces thermal resistance and potentially lowers production costs by using a more user-friendly thermally conductive element 24. QUOTES INCLUDED IN THE DESCRIPTION

[0000] 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

[0000] DE 202009018077 U1

[0002]

Claims

[1] Device for cooling an electronic component (22) of a motor vehicle, comprising at least a printed circuit board (12), at least one electronic component (22) to be cooled arranged on the printed circuit board (12), at least one cooler (16) for cooling the electronic component (22), at least one thermally conductive element (24) arranged between the electronic component (22) and the cooler (16), comprising at least one housing (11) which at least partially encloses the printed circuit board (12), characterized by, that on a side of the circuit board (12) opposite the electronic component (22) at least one stiffening element (14) is provided, which is arranged on the circuit board (12) to stiffen it, wherein at least one spring-loaded fastening (18, 20) is provided for fixing the stiffening element (14) together with the circuit board (12) to the cooler (16) and / or to the housing (11), wherein the spring-loaded fastening (18, 20) acts on the stiffening element (14). [2] Device according to claim 1, characterized by , that the spring-loaded mounting (18,20) is designed such that the electronic component (42) experiences a force in the direction of the cooler (16). [3] Device according to any one of the preceding claims, characterized by that the stiffening element (14) comprises at least one, in particular sleeve-shaped, receptacle (13) and / or the circuit board (12) comprises at least one opening (28) for receiving the spring-loaded fastening (18, 20). [4] Device according to any one of the preceding claims, characterized by that the cooler (16) and / or the housing (11) includes at least one receptacle (19) for receiving the spring-loaded mounting (18, 20). [5] Device according to any one of the preceding claims, characterized by , that the resilient fastening (18,20) comprises at least one fastening means (18), in particular a screw, and a spring (20), wherein the spring (20) is arranged between a counter surface on the fastening means (18), in particular a screw head, and the surface of the stiffening element (14). [6] Device according to any one of the preceding claims, characterized by , that the stiffening element (14) comprises at least one, in particular rectangular, base body and / or at least one arm (10) projecting from a base body of the stiffening element (14). [7] Device according to any one of the preceding claims, characterized by, that the arm (10) and / or the base body accommodates the spring attachment (18,20). [8] Device according to any one of the preceding claims, characterized by , that the cooler (16) completely covers a surface of the electronic component (22) to be cooled and the receptacle (19) on the cooler (16) is located outside the area covering the surface of the electronic component (22) to be cooled. [9] Device according to any one of the preceding claims, characterized by , that at least one further electronic component (22) is provided which is arranged adjacent to the cooler (16) for heat dissipation via the cooler (16). [10] Method for assembling a device for cooling an electronic component (22) in a motor vehicle, particularly according to claim 1, wherein a cooler (16) and / or a housing (11) is provided, wherein a heat-conducting element (24) is arranged on the cooler (16) and / or on the housing (11), wherein at least one printed circuit board (12) is provided with at least one electronic component (22) to be cooled and at least one stiffening element (14) which is arranged on a side of the printed circuit board (12) opposite the electronic component (22), wherein the printed circuit board (12) is positioned such that a surface of the electronic component (22) to be cooled comes into contact with the heat-conducting element (24), wherein a force (32) is exerted on the printed circuit board (12) in the direction of the cooler (16) and / or the housing (11), and wherein at least one resilient fastening (18,20) is provided for fixing the stiffening element (14) together with the circuit board (12) to the cooler (16) and / or to the housing (11). [11] Procedure according to the preceding procedure claim, characterized by , that the spring-loaded fastening (18,20) is fixed via at least one receptacle (19) on the cooler (16) and / or on the housing (11) and is guided through at least one receptacle (13) in the stiffening element (14) and through at least one opening (28) in the circuit board (12). [12] Method according to any of the preceding method claims, characterized by , that the force (32) on the circuit board (12) is selected such that a desired position of the electronic component (22) is established relative to the cooler (16) or the housing (11) and / or the thermally conductive element (24). [13] Method according to any one of the preceding claims, characterized by, that the receptacle (13) of the stiffening element (14) and the opening (28) in the circuit board (12) are aligned with the receptacle (19) on the cooler (16) or on the housing (11). [14] Method according to any of the preceding method claims, characterized by , that the stiffening element (14) is fixed in at least one corresponding opening (28) in the circuit board (12) via at least one sleeve-shaped receptacle (13). [15] Method according to any of the preceding method claims, characterized by , that the stiffening element (14) comprises at least one stiffening frame, in particular rectangular, and at least one arm (15) extending from the stiffening frame, wherein the resilient fastening (18, 20) is inserted through the arm (15) and / or the stiffening frame.

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