Cooling device for cooling electronic components

Abstract

The invention relates to a cooling device (10; 10a) for cooling electronic components (2 to 4), with a heat spreader (12) operating according to the evaporator principle, which is at least indirectly connected to the components (2 to 4) in a heat-conducting manner on a side facing the components (2 to 4), wherein the heat spreader (12) is connected to a heat transfer element (20; 20a) designed as a separate component for the heat-conducting connection to the components (2 to 4).

Description

Technical field

[0001] The invention relates to a cooling device for cooling electronic components, which can be adapted particularly easily to different circuit carriers supporting the components. Furthermore, the invention relates to an assembly with a cooling device designed according to the invention. State of the art

[0002] From US 6,966,361 B2 a cooling device for cooling electronic components with the features of the preamble of claim 1 is known. The known cooling device has a heat spreader which operates according to the evaporator principle and in which channels for guiding an evaporable coolant are arranged. The heat spreader has cooling fins or the like on its side facing away from the components and is connected to the components in a heat-conducting manner on its side facing the components. In order to adapt the heat spreader to components which are arranged differently or have different heights and yet still enable an arrangement of the heat spreader, for example, parallel to a circuit carrier carrying the components, the heat spreader has elevations on its underside facing the components which are formed integrally or monolithically with the heat spreader. This makes it necessary to adapt the heat spreader to the respective application orto adapt to the topography of the components, which in the case of a heat spreader operating according to the evaporator principle usually requires a relatively high expenditure for the production of, for example, casting molds for the heat spreader.

[0003] From DD 204 149 B it is also known to form a heat transfer element between components and a heat spreader in the form of a heat-conducting, inflatable balloon in which an evaporable cooling medium is arranged, wherein the balloon clings to both the components and the heat spreader in a heat-conducting manner. Disclosure of the invention

[0004] The cooling device according to the invention for cooling electronic components with the features of claim 1 has the advantage that it can be adapted particularly easily or with relatively low investment costs to differently designed assemblies with correspondingly differently arranged components on a circuit carrier.

[0005] The invention is based on the idea of using a standardized heat spreader that can be combined with heat transfer elements adapted to the respective application, thus enabling individual adaptation of the cooling device to the respective application or circuit layout. In other words, this means that one and the same heat spreader can typically be used for different applications, which can be combined with different heat transfer elements.

[0006] Against the background of the above explanations, a cooling device according to the invention for cooling electronic components with the features of claim 1 therefore has a heat spreader operating according to the evaporator principle, which is at least indirectly thermally connected to the components on a side facing the components. The cooling device is characterized in that the heat spreader, for thermally conductive connection to the components, is connected to a heat transfer element designed as a separate component, which is at least indirectly connected to the components on the side facing the components and to the heat spreader on the side facing the heat spreader.

[0007] Advantageous further developments of the cooling device according to the invention for cooling electronic components are listed in the subclaims.

[0008] There are various options for designing the heat transfer element as simply, precisely, and advantageously from a manufacturing perspective. In particular, the heat transfer element can be designed as a cast part or as a component manufactured using an additive process. The heat transfer element has a flat end face on the side facing the heat spreader, which is connected to the heat spreader, and has elevations adapted to the topography of the components on the side facing the components. The largest possible heat transfer surface is formed both over the flat end face and over the elevations adapted to the topography of the components in order to optimize heat transfer from the components via the heat transfer element to the heat spreader.

[0009] Alternatively, or depending on the application, in addition to the heat transfer element, the heat transfer element may be provided with an additional heat transfer element filled with a vaporizable refrigerant. Using such an additional heat transfer element, heat-generating components that are not aligned with the heat spreader or the heat transfer element, for example, can be thermally coupled to the heat transfer element particularly easily and effectively.

[0010] In a preferred development of the last proposal, the heat transfer element is directly connected to the heat spreader. A direct connection is understood to mean that only a thermally conductive adhesive, a welded or soldered joint, or similar, serves to thermally couple the heat transfer element and the heat spreader.

[0011] Alternatively, it can also be provided that the additional heat transfer element filled with the refrigerant is arranged at least partially integrated in the (solid) body of the heat transfer element.

[0012] This makes it possible, for example, to create special heat paths to enable heat transfer from the components to defined points on the heat spreader.

[0013] For a compact design of the heat spreader, it is particularly preferred if it is designed as a flat, cuboid heat spreader.

[0014] The cooling effect of the heat spreader can be improved or made more effective if the heat spreader is connected to at least one additional cooling element on the side facing away from the heat transfer element. This at least one additional cooling element is preferably designed as a cooling fin.

[0015] The thermal coupling of the heat transfer element to the components is preferably achieved using a thermally conductive medium, such as a thermally conductive adhesive, thermally conductive paste, or a so-called gap pad. This, in particular, prevents thermal stress or strain on the components during the production process. Furthermore, components that are difficult to access using other, alternative connection techniques, such as soldering or welding, can be very easily connected to the thermally conductive medium.

[0016] Finally, the invention also includes an assembly comprising a circuit carrier on which heat-generating electronic components are arranged and a cooling device designed according to the invention as described so far.

[0017] Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments of the invention and from the drawings. Short description of the drawings The Fig. 1 and Fig. 2 show, in simplified sectional views, differently designed cooling devices for cooling electronic components. Embodiments of the invention

[0018] Identical elements or elements with the same function are provided with the same reference numbers in the figures.

[0019] In the Fig. 1 shows a highly simplified representation of an assembly 100 which is, for example, a component of an aggregate in the computer and / or server sector, in vehicle electronics or in aerospace technology.

[0020] The assembly 100 comprises a circuit carrier 1, in particular in the form of a printed circuit board, on which, in the illustrated embodiment, three heat-generating components 2 to 4 are arranged on an upper side of the circuit carrier 1. For example, the components 2 to 4 are electrically connected to the circuit carrier 1 via solder connections 5. The components 2 to 4 are part of an electronic circuit (not shown in detail), wherein the components 2 to 4 are characterized by the fact that they generate heat during operation. To ensure proper operation of the assembly 100, it is necessary to cool the components 2 to 4. This is done by means of a cooling device 10.

[0021] The cooling device 10 comprises a block-shaped heat spreader 12 that operates according to the evaporator principle. This means that a refrigerant is arranged within the interior of the heat spreader 12 within a channel structure of the heat spreader 12. This refrigerant evaporates through heat transfer from the components 2 to 4 and circulates within the heat spreader 12, condensing in a region where the boiling point of the coolant is undershot, and then flowing back toward the components 2 to 4 to be cooled. Such a heat spreader 12, its basic structure, and its mode of operation are known per se from the prior art and will therefore not be described further.

[0022] The heat spreader 12 can furthermore be connected to at least one additional cooling element 14, in particular in the form of a plurality of cooling fins 16, on its upper side facing away from the components 2 to 4, wherein the at least one additional cooling element 14 is either produced monolithically with the heat spreader 12 or is separate from the heat spreader 12 and then connected to the heat spreader 12 in a heat-conducting manner.

[0023] On the side facing components 2 to 4, heat spreader 12 is thermally connected to a heat transfer element 20 formed as a separate component. The connection between heat spreader 12 and heat transfer element 20 is established, for example, by a thermally conductive adhesive (not shown) or, depending on the material of heat spreader 12 and heat transfer element 20, by a welded or soldered connection.

[0024] The heat transfer element 20 has, on the side facing the heat spreader 12, a flat end face 22, the size of which is adapted to the side of the heat spreader 12 facing it, wherein the corresponding surfaces preferably completely overlap.

[0025] The heat transfer element 20 can, for example, be formed as a cast part or as a cast body made of aluminum, or it can be formed using an additive manufacturing process. Preferably, the so-called SLM process is used to produce the heat transfer element 20, in which a plurality of superimposed layers of a metallic powder are selectively melted by means of a laser beam, with the region of the respective layer that solidifies after melting forming the heat transfer element 20.

[0026] It is also conceivable, particularly in connection with the additive manufacturing of the heat transfer element 20, to construct the heat transfer element 20 directly on the side of the heat spreader 12 facing it.

[0027] The heat transfer element 20 has, on the side facing the components 2 to 4, three elevations 23 to 25 formed monolithically with the heat transfer element 20, the geometry of which, i.e. the cross section and height of which elevations is adapted to the topography and arrangement of the components 2 to 4 on the circuit carrier 1, such that the heat spreader 12 is preferably arranged parallel to the circuit carrier 1, and the elevations 23 to 25 can be positioned in thermal contact with the upper sides of the components 2 to 4. The thermal contact of the elevations 23 to 25 with the upper sides of the components 2 to 4 is preferably effected in each case by means of a layer of a heat-conducting medium 27, wherein the layer thickness of the heat-conducting medium 27 can optionally vary.

[0028] In the Fig.2 shows an assembly 100a whose cooling device 10a differs from the cooling device 10 in that the heat transfer element 20a additionally interacts with at least one, in the illustrated embodiment with three, tubular or similarly shaped additional heat transfer elements 30 to 32, each filled with an evaporable coolant. The additional heat transfer elements 30 to 32 are thermally connected, on the one hand, to the upper side of the components 2 to 4 via the thermally conductive adhesive 27, and, on the other hand, to the underside of the heat spreader 12.

[0029] The additional heat transfer element 30 has a bent or step-like shape in order to contact the component 2 arranged laterally to the heat spreader 12. In contrast, the two additional heat transfer elements 31 and 32 are each U-shaped in cross section, wherein the additional heat transfer elements 31 and 32 are simultaneously an integral part of the heat transfer element 20a, ie, are embedded in the heat transfer element 20a.

[0030] The cooling device 10, 10a or the assembly 100, 100a described so far can be modified in a variety of ways without deviating from the inventive concept. In particular, it is pointed out that other components can also be arranged between the components 2 to 4 that generate no or a non-critical amount of heat during operation and thus do not need to be thermally connected to the heat spreader 12. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 6,966,361 B2

[0002] DD 204 149 B

[0003]

Claims

[1] Cooling device (10; 10a) for cooling electronic components (2 to 4), with a heat spreader (12) operating according to the evaporator principle, which is at least indirectly connected to the components (2 to 4) in a heat-conducting manner on a side facing the components (2 to 4), characterized by that the heat spreader (12) is connected to a heat transfer element (20; 20a) designed as a separate component for the heat-conducting connection to the components (2 to 4), which heat transfer element is connected at least indirectly to the components (2 to 4) on the side facing the components (2 to 4) and to the heat spreader (12) on the side facing the heat spreader (12). [2] Cooling device according to claim 1, characterized byin that the heat transfer element (20; 20a) is designed as a cast part or as a component produced in an additive process, wherein the heat transfer element (20; 20a) has, on the side facing the heat spreader (12), a flat end face (22) which is connected to the heat spreader (12), and which has, on the side facing the components (2 to 4), elevations (23 to 25) adapted to the topography of the components (2 to 4). [3] Cooling device according to claim 1 or 2, characterized by that in addition to the heat transfer element (20a), an additional heat transfer element (30 to 32) filled with an evaporable refrigerant is provided, which is thermally connected to a component (2 to 4). [4] Cooling device according to claim 3, characterized by that the additional heat transfer element (30) is directly connected to the heat spreader (12). [5] Cooling device according to claim 3, characterized bythat the additional heat transfer element (31, 32) is arranged at least partially integrated in the heat transfer element (20a). [6] Cooling device according to one of claims 1 to 5, characterized by that the heat spreader (12) is designed as a flat, cuboid heat spreader (12). [7] Cooling device according to one of claims 1 to 6, characterized by that the heat spreader (12) is connected to at least one additional cooling element (14) on the side facing away from the heat transfer element (20; 20a). [8] Cooling device according to claim 7, characterized by that the at least one additional cooling element (14) is designed as a cooling fin (16). [9] Cooling device according to one of claims 1 to 8, characterized by that the heat transfer element (20; 20a) is connected to the components (2 to 4) by means of a heat-conducting medium (27). [10] Assembly (100; 100a) comprising a circuit carrier (1) on which heat-generating electronic components (2 to 4) are arranged, and with a cooling device (10; 10a) designed according to one of claims 1 to 9.

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