Method for producing a cooling device

Abstract

The invention relates to a method for producing a cooling device (1) with a base element (10) and a cover element (11) connected thereto, wherein a cooling structure with cooling elements (6) is arranged between the base element (10) and the cover element (11), comprising the steps of providing a material and forming a cooling structure from the material, wherein a sintering powder is used as the material, from which at least one green compact is produced by pressing, the green compact is sintered to form a preform (19), and the cooling structure in the form of cooling elements (6) is produced from the preform (19) by forming, for which purpose a part of the preform (19) is pressed through a forming tool (20), and after the cooling structure has been arranged between the base element (10) and the cover element (11), the base element (10) is materially joined to the cover element (11).

Description

[0001] The invention relates to a method for producing a cooling device with a base element and a cover element connected thereto, wherein a cooling structure with cooling elements is arranged between the base element and the cover element, comprising the steps of providing a material and forming a cooling structure from the material.

[0002] Furthermore, the invention relates to a cooling device comprising a base element and a cover element connected thereto, wherein a cooling structure with cooling elements is arranged between the base element and the cover element.

[0003] So-called power electronic components, such as power semiconductors, are well known in the art. Such components are frequently used, for example, in motor vehicles. It is also known that these components generate large amounts of heat during operation, which often requires dissipation with the aid of a cooling medium. For this purpose, a wide variety of coolers are known in the art, including so-called pin fin heat sinks, which are surrounded by a cooling medium and thus transfer the heat from the pins to the cooling medium. For example,DE 10 2019 108 106 A1 describes a cooler for a power semiconductor in an inverter, wherein the cooler is designed in two parts and comprises: a base plate as the first part, which can be connected to the power semiconductor in a heat-conducting manner; a heat sink as the second part, which is arranged on the base plate, wherein the heat sink has at least one wave-shaped recess which is formed continuously from a side of the heat sink facing away from the base plate to a side facing the heat sink; wherein the first and second parts are connected to one another and are coated by means of a layer which protects both parts from electrochemical reduction.

[0004] From DE 10 2018 216 859 A1 a device for cooling components is known, comprising: a first and a second base body; cylindrical and / or conical first cooling fins formed in the first base body, around which a coolant can flow, and cylindrical and / or conical second cooling fins formed in the second base body, around which the coolant can flow, wherein the second is joined to the first base body in such a way that the second cooling fins come to lie between the first cooling fins without touching the first base body.

[0005] The present invention is based on the object of simplifying the manufacture of a cooling device and of providing a corresponding cooling device for components with improved cooling performance.

[0006] The object of the invention is achieved by the method mentioned at the outset, according to which it is provided that a sintering powder is used as the material, from which at least one green compact is produced by pressing, that the green compact is sintered to form a preform, and that the cooling structure in the form of cooling elements is produced from the preform by forming, for which purpose a part of the preform is pressed through a forming tool, and that after the cooling structure has been arranged between the base element and the cover element, the base element is connected to the cover element in a material-to-material manner.

[0007] Furthermore, the object of the invention is achieved with the cooling device mentioned at the outset, in which the cooling structure is made of a formed sintered material and the base element is integrally connected to the cover element.

[0008] The advantage here is that no waste material is generated for the cooling elements produced by forming, as is the case with machining, for example. In addition, several or all of the cooling elements of the cooling device can be manufactured simultaneously, which can lead to a corresponding increase in productivity. For forming, it is advantageous that the preform, although it already has a corresponding level of strength due to sintering, is easier to form than a solid material due to its pores. During the forming of the preform into the cooling elements, stresses can be generated in the elements, which have a positive effect on their mechanical behavior during use of the cooling device.The integral connection between the base element and the cover element provides a fluid-tight cooling device for the cooling structure—apart from an inlet and outlet for a cooling fluid—so that it can be easily used in a wide variety of applications without the need for any special precautions (except for integrating the cooling device into a cooling circuit). The enclosed design of the cooling structure makes it particularly easy to use in electronic applications.

[0009] According to one embodiment of the invention, it can be provided that the base element is / are produced from at least one preform and / or the cover element is / are produced from at least one preform. By producing the base element and / or the cover element by sintering, the base element and / or the cover element can be more easily adapted to the cooling structure.

[0010] According to a further embodiment of the invention, it is advantageous if cooling elements of the cooling structure are formed integrally with the base element and / or cooling elements of the cooling structure are formed integrally with the cover element. This makes it possible to produce both the cooling elements and the base element or the cover element in a single process step, thus making their production more economical. Furthermore, the integral design eliminates the need for any additional measures to fix the position of the cooling structure.

[0011] According to another embodiment of the invention, it can be provided that the integral connection is formed outside the area of the cooling structure. This prevents any influence on the cooling structure, e.g., thermal influence, caused by the formation of the integral connection. Furthermore, it is thus possible to form the cooling structure regardless of the requirements for the formation of the integral connection.

[0012] According to a further embodiment of the invention, a joining gap can be formed in the base element or cover element to form the bonded joint. This makes it possible to define an area in which the bonded joint is formed, so that subsequent interaction between the cooling structure and the bonded joint can be more easily avoided during the production of the connection. This also makes it easier to automate the "bonded joining" process step, particularly when a filler material is used for the bonded joint, since the joining gap can avoid or prevent the filler material from running during the formation of the bonded joint.

[0013] According to a further embodiment of the invention, it can be provided that the material connection is or is formed as a soldered connection in order to keep the temperature load of the cooling structure low during the formation of the material connection and to keep or avoid stress relief in the cooling elements as low as possible.

[0014] According to one variant, the soldered joint can be created using inductive soldering or sinter soldering. Inductive soldering allows the heat input into the base element and the cover element to be limited to a very narrow area during the formation of the bonded joint. On the other hand, sinter soldering can simplify the process by forming the bonded joint during passage through a sintering furnace. This also allows for a more uniform property profile across the entire cooling device.

[0015] For greater stability of the cooling device, one embodiment of the invention provides for at least some of the cooling elements to be connected to both the base element and the cover element. This also allows for a reduction in the thickness of the base element or the cover element, thereby reducing the thermal resistance and thus increasing the cooling capacity of the cooling device.

[0016] In order to simplify the connection of the cooling element to the cover element or the base element, according to an embodiment variant of the invention, joining recesses can be formed for receiving a filler material in heads of the cooling elements, which are connected to both the base element and the cover element.

[0017] To improve corrosion resistance, a coating can be applied to the cooling structure according to a further embodiment of the invention.

[0018] According to a further embodiment of the invention, the coating can be carried out before or after the material-to-material connection of the base element to the cover element. By applying the coating before the material-to-material connection is created, the coating process itself can be simplified, particularly in hard-to-reach areas. By applying the coating after the material-to-material connection is created, the placement of the material-to-material connection on the base element and the cover element can be simplified, in particular, these can be formed closer to the cooling structure, since covering these areas can be avoided to prevent deposition of the coating in these areas.

[0019] For a better understanding of the invention, it is explained in more detail with reference to the following figures.

[0020] They show in a simplified, schematic representation: Fig. 1 a cooling device with a component to be cooled, cut in side view; Fig. 2 a section of a cooling device in an oblique view; Fig. 3 a variant of a cooling device in an oblique view; Fig. 4 a longitudinal section through the cooling device according to Fig. 3; Fig. 5 a section of another embodiment of a cooling device in longitudinal section; Fig. 6 a variant of a preform; Fig. 7 a variant of a tool for producing the cooling device.

[0021] By way of introduction, it should be noted that in the variously described embodiments, identical parts are provided with identical reference symbols or component designations, whereby the disclosures contained in the entire description can be applied mutatis mutandis to identical parts with identical reference symbols or component designations. Furthermore, the positional information chosen in the description, such as top, bottom, side, etc., refers to the directly described and illustrated figure, and in the event of a change in position, these positional information must be applied mutatis mutandis to the new position.

[0022] In Fig. 1 shows a cooling device 1 in side view.

[0023] The cooling device 1 serves to cool one or more components 2 or an assembly. For this purpose, the cooling device 1 rests with a rear side 3 against the at least one component 2, in particular directly, thus preferably being in direct contact with the component 2 for heat exchange.

[0024] The component 2 is preferably an electronic component, in particular a so-called power electronics component or high-performance electronics component or a power semiconductor or high-performance semiconductor. In particular, such components 2 or assemblies made of / with these components 2 can be provided for a power in the range from several kW up to MW. Such components 2 are used, for example, to convert electrical energy using switching electronic components. Typical applications are converters or frequency converters in the field of electrical drive technology, solar inverters and converters for wind turbines for feeding renewable energy into the grid or switched-mode power supplies, generally the conversion of alternating voltage into direct voltage using rectifiers, the conversion of direct voltage into alternating voltage using inverters, controls, for example in the drive technology of an electric drive in electric vehicles orHybrid vehicles, battery management systems, etc. A power electronics component can, for example, be a semiconductor, in particular a so-called power semiconductor, e.g. an IGBT.

[0025] Since such components 2 are known from the relevant prior art, reference is made to this prior art to avoid repetition of details.

[0026] The cooling device 1 comprises a base element 4, which has a cooling structure on a first surface 5. The cooling structure is formed by cooling elements 6, which are arranged on the base element 4 so as to protrude beyond the first surface 5 and are integrally connected thereto, as is also shown in Fig. 2 is evident.

[0027] Within the scope of the invention, it is possible for several cooling devices 1 according to the invention to be combined with one another to form a cooling device group per component 2 or assembly comprising / with at least one such component 2. In particular, the cooling devices 1 can also be assembled modularly to form a cooling device group.

[0028] The base element 4 and the cooling elements 6 are made of or consist of a sintered material. Furthermore, the cooling elements 6 are produced by forming the base element 4 or a preform therefor.

[0029] In the preferred embodiment, the base element 4 and the cooling elements 6 have a density of at least 98%, in particular at least 98.5%, preferably at least 99%, of the full density of the material used.

[0030] The solid density refers to the density of a cooling device manufactured using melt metallurgy from the same material, i.e., a component made of a solid material. Solid material refers to a metallic material that—with the exception of imperfections—does not contain any pores, as is typically found in sintered components.

[0031] The cooling elements 6 are designed to be surrounded by a cooling fluid, for example, water, so that the heat absorbed by the cooling device 1 is dissipated via this cooling fluid. Preferably, the cooling device 1 is a so-called pin fin cooling device.

[0032] The cooling elements 6 of the illustrated embodiment are cylindrical. However, they can also have a different shape, for example, a truncated cone, a mushroom shape, or generally a cross-section that widens or tapers toward a cooling element head 7, for example, a truncated pyramid shape.

[0033] The cross-section of the cooling elements 6 can be circular, oval, diamond-shaped, square, etc.

[0034] Furthermore, all cooling elements 6 can be of the same design. However, it is also possible to arrange or combine cooling elements 6 of different shapes on a base element 4.

[0035] The cooling elements 6 may preferably have a height 8 above the first surface 5 of the base element 4 which is between 2 mm and 20 mm.

[0036] In the simplest embodiment of the cooling device 1, all cooling elements 6 of the cooling device 1 have the same height 8 within the tolerances. However, within the scope of the invention, it is possible for some of the cooling elements 6 to have a lower height than the remaining cooling elements 6. For example, edge-positioned cooling elements 6 can be higher than the rest, or the cooling elements 6 can have a height progression from lower or higher in the middle of the cooling device 1 to higher or lower at the edge of the cooling device 1. Other embodiments with different heights 8 are possible within the scope of the invention.

[0037] Furthermore, it can be provided that per dm 2first surface 5 between 300 and 1300, in particular between 300 and 1000, for example between 300 and 750, cooling elements 6 are arranged or formed. This number in particular has proven advantageous with regard to the manufacture of the cooling device 1, ie the deformation of the base element 4 into the cooling elements 6, since it can prevent or reduce damage to the cooling elements 6 or incompletely formed cooling elements 6.

[0038] As is particularly evident from Fig. 1, according to one embodiment variant of the cooling device 1, the rear side 3 can be formed with a flat surface. However, it is also possible for the rear side 3 to be formed with one or more recesses 9 in which a component 2 is at least partially received. This allows for a better connection of the component 2 to the cooling device 1. In general, the component 2 can be glued or screwed or soldered or sintered to the cooling device 1, for example.

[0039] The at least one recess 9 can be produced simultaneously with the cooling elements 6 during the production of the cooling elements 6. The at least one recess 9 also makes it possible to produce cooling elements 6 whose height 8 is greater than that of the remaining cooling elements 6.

[0040] The cooling device 1 comprises a base element 10 and a cover element 11 connected to the base element 10. In the Fig. In the embodiment of the cooling device 1 shown in Figure 1, the base element 4 with the cooling elements 6 is arranged on the bottom element 10, which also forms the rear side 3, and in particular is connected thereto. However, the base element 4 with the cooling elements 6 can also be arranged on the cover element 11, in particular be connected thereto.

[0041] According to embodiments of the invention, the base element 4 can also form the base element 10 and / or the cover element 11. In the embodiment "and," two base elements 4 are present, one forming the base element 10 and the other the cover element 11. Depending on the size of the cooling device 1, more than two base elements 4 with cooling elements 6 can be arranged.

[0042] The design variant “Base element 4 forms the floor element 10” is shown in the Fig. 3 and Fig. 4. The variant “a base element 4 forms the base element 10 and a further base element 4 forms the cover element 11” is shown in detail in Fig. 5 shown.

[0043] In the preferred embodiment, the base element 10 or the cover element 11, or the base element 10 and the cover element 11, are made of a sintered material or consist thereof, as will be explained in more detail below with reference to the manufacture of the base element 4 with the cooling elements 6. In the event that the base element 10 or the cover element 11 is combined with a component made of a non-sintered material, this can be, for example, a punched component or a cut-out component, in particular a laser-cut component, or a cast component, etc.

[0044] Since the / a base element 4 can form the base element 10 and / or the cover element 11, in the preferred embodiment variant the (all) cooling elements 6 are formed in one piece with the base element 10 or the cover element 11 or a part of the cooling elements 6 is formed in one piece with the base element 10 and the remaining part of the cooling elements 6 is formed in one piece with the cover element 11.

[0045] It should be noted that in the case of several base elements 4 with cooling elements 6, all base elements 4 can also be designed in the same way (apart from the Fig. 5 shown embodiment of the cooling device 1).

[0046] The cooling device 1 further comprises an inlet element 12 or a plurality of inlet elements 12 for supplying a liquid or gaseous cooling fluid into the cooling device 1 and an outlet element 12 or a plurality of outlet elements 12 for discharging the cooling fluid from the cooling device 1. In the Fig. In the embodiment shown in Figure 3, the at least one inlet element 12 and the at least one outlet element 13 are arranged on the cover element 11. However, the at least one inlet element 12 and the at least one outlet element 13 can also be arranged in the base element 10. Furthermore, the at least one inlet element 12 can be arranged on the base element 10 and the at least one outlet element 13 can be arranged on the cover element 11 (or vice versa).

[0047] The inlet element 10 is in flow communication via an opening in the cover element 11 (or base element 10) with a gap 14 between the base element 10 and the cover element 11. The same applies to the outlet element 13. The cooling elements 6 are arranged in the gap 14. The inlet element 12 and the outlet element 13 also serve, in particular, to integrate the cooling device 1 into a cooling circuit.

[0048] The base element 10 is integrally connected to the cover element 11. In principle, the integral connection can be an adhesive connection or a welded connection. In the preferred embodiment, however, the integral connection is a soldered connection, for which a suitable solder (as a filler material) is preferably used. The soldered connection has the advantage that the cooling device 1 can also be exposed to higher temperatures (compared to an adhesive connection), and that the thermal stress on the formed cooling elements 6 is lower than with a welded connection.

[0049] Due to the porosity of the base element 10 and / or the cover element 11 caused by the sintering process, a type of "claw" can be achieved if necessary, as the filler material penetrates these pores and at least partially fills them. This can improve the bond strength and fluid tightness of the material connection.

[0050] To form the fluid-tight intermediate space 14 (with the exception of the inlet element 12 and the outlet element 13), the material connection is preferably formed completely around the cooling structure (viewed in plan view) between the base element 10 and the cover element 11. However, it is also possible for a sealing element to be arranged between the base element 10 and the cover element 11 and for the material connection to be formed only in discrete areas between the base element 10 and the cover element 11 in this embodiment.

[0051] In principle, the solder joint can be made using any suitable method. However, inductive soldering or sinter soldering (preferably with a filler metal) is preferred.

[0052] During inductive brazing, only the area where the brazed joint is formed is heated. In sinter brazing, however, the filler material is introduced between the base element 10 and the cover element 11, and these are then placed into a sintering furnace together with the already produced cooling structure.

[0053] The soldered joint can, for example, be designed in the form of a fillet weld. For this purpose, a butt joint, a T-joint, or a corner joint can be formed between the base element 10 and the cover element 11, as is known per se for soldered joints. According to a further embodiment of the cooling device 1, a joint gap 15 for receiving the filler material is formed for forming the material connection between the base element 10 and the cover element 11. In the Fig. 3 and Fig. In the embodiment shown in Figure 4, this is achieved in that the base element 10 has a collar 16, on which the cover element 11 is arranged at a distance from a side wall 17 of the collar 16, forming the (circumferential) joining gap 15. Other designs of the joining gap are possible within the scope of the invention.

[0054] The joint gap 15 can, for example, have a width between 0.05 mm and 3 mm and a depth between 0.1 mm and 5 mm.

[0055] As can be seen from the Fig. 3 and Fig. 4, the joining gap 15 is preferably formed exclusively outside of and at a distance from the cooling structure. Thus, the material connection is also preferably formed outside the region of and at a distance from the cooling structure. The distance between the joining gap 15 and the nearest cooling element 6 can be between at least 3 mm and at least 15 mm.

[0056] The cooling elements 6 can be arranged at a distance of between 0.5 mm and 5 mm from each other. The distance is measured between two cooling elements 6 arranged directly next to each other. Fig. In the embodiment shown in Figure 5, the distance between the cooling elements 6 on the base element 10 and between the cooling elements 6 on the cover element 11 is larger, so that gaps are formed between the respective cooling elements 6, into which gaps the cooling elements 6 of the base element 10 and the cover element 11 engage. In the finished cooling device 1, the distances between the cooling elements 6 can again be selected from the range mentioned above.

[0057] The base element 4 (and thus also the bottom element 10 and / or the cover element 11) can, for example, have an element height of 18 (see Fig. 2) between 3 mm and 5 mm. However, the base element 4 can also have an element height 18 of a maximum of 3 mm. In particular, the base element 4 can also have an element height 18 between 1 mm and 2.5 mm. The element height 18 of the (plate-shaped) base element 4 is measured between its rear side 3 and the first surface 5. If a recess 9 is provided in the rear side 4, the element height 18 is measured next to the recess 9.

[0058] To manufacture the cooling device 1, a sintering powder or a powder used in powder metallurgy, in particular a metallic powder, is used. Preferably, a sintering powder is used that has correspondingly good thermal conductivity. In particular, a sintering powder based on aluminum or an aluminum alloy, or based on copper or a copper alloy, or an MMC (metal matrix composite) powder is used.

[0059] The cooling device 1 is manufactured using a powder metallurgical process, thus it is preferably a sintered component. For this purpose, a green compact is produced in a corresponding mold (die) from a sinter powder, which can be produced by mixing the individual (metallic) powders, whereby the powders can optionally be used pre-alloyed. The green compact preferably has a density of at least 80%, in particular between 80% and 96%, of the full density of the material.

[0060] The green compact is then dewaxed at conventional temperatures and sintered in one, two, or multiple stages, and then cooled, preferably to room temperature. Sintering can be performed, for example, at a temperature between 500 °C and 1300 °C.

[0061] Since these procedures and the process parameters used are also known from the state of the art, reference is made to the relevant state of the art in order to avoid repetition.

[0062] Sintering turns the green body into a preform 19, as shown in the example in Fig. 6. The preform 19 can be designed as a flat plate, so that the rear side 3 and the first surface 5 can run parallel to one another. A preform 19, in particular for the production of the base element 10, can also already have the support surfaces for the support of the cover element 11, e.g. the collar 16, for forming the intermediate space 14 between the base element 10 and the cover element 11. Likewise, a preform 19, in particular for the production of the cover element 11, can have the inlet element 12 and / or the outlet element 13.

[0063] Other shapes of the first surface 5 of the preform 19 are possible with a view to improving the formability of the preform 19. Thus, initial pin fin attachments or cooling element attachments (circular, oval, elliptical, etc.) with a height between 0.1 mm and 2.0 mm can be preformed. Additionally, structures (waves, ribs, etc.) can be deliberately introduced into the first surface 5 of the preform 19 to promote turbulence of the cooling fluid, if necessary.

[0064] The preform 19 can then be further densified. The further densification can take place simultaneously with the forming of the preform 19 into the cooling elements 6.

[0065] The preform 19 is formed in a mold 20. For this purpose, the preform 19 is inserted into the mold 20 or placed against it. In the simplest case, the mold 20 for producing the cooling elements 6 is formed by a perforated plate 21. The perforated plate 21 has recesses 22, in particular openings, into or through which a portion of the material of the preform 19 is pressed, thereby forming the cooling elements 6. For the formation of the collar 16, a corresponding recess 23 can be provided in the perforated plate 21, depending on its shape.

[0066] The remainder of the material of the preform 19, which is not pressed into or through the mold 20, forms the base element 4, i.e. preferably the bottom element 10 or the cover element 11. In this case, the later desired element height 18 of the base element 4 is already taken into account on the preform 19 depending on the deformation to be carried out to form the cooling elements 6.

[0067] The recesses 22, 23, ie their cross-section, are adapted to the cross-section of the cooling elements 6 to be produced.

[0068] The forming tool 20 can also have a different appearance, i.e., it does not necessarily have to be a perforated plate 21. In particular, the forming tool 20 can be designed in a "cup-shaped" manner as a die.

[0069] For the forming process, a punch 24 or, generally, a pressure tool is applied to the back side 3 of the preform 19, which also forms the back side 3 of the base element 4, and pressed onto the preform 19 with a predeterminable pressure. The forming process can, for example, take place at a pressure between 700 MPa and 1600 MPa. Furthermore, the forming process can take place for a time of up to 10 seconds, in particular between 0.1 seconds and 10 seconds. Furthermore, the forming can preferably be carried out at room temperature (20 °C), ie cold, or the forming can also be carried out after preheating the preform 20 to a temperature between 50 °C and 300 °C, for example between 50 °C and 150 °C, and / or in / with a forming tool 18 heated to a temperature between 50 °C and 300 °C, for example between 50 °C and 150 °C.

[0070] After shaping, ie, the forming of the preform 19, the cooling device 1 can be reworked. For example, the cooling elements 6 can be calibrated in height or generally re-compacted, for example in the free ends, for which a stamp can also be used. In addition, the first surface 5 and the cooling elements 6 can be coated with a coating 25 (see Fig. 5), e.g., a corrosion-resistant coating, such as a galvanic Ni-P coating 25. The coating 25 can be applied or deposited before or after the material-to-metal bonding of the base element 10 to the cover element 11. Coating before the material-to-metal bonding of the base element 10 to the cover element 11 has the advantage that the surfaces to be coated are more easily accessible. If subsequent removal of the coating 25 in the connection areas between the base element 10 and the cover element 11 before the material-to-metal bond is formed is not desired, these areas in which the material-to-metal bond is formed can be covered, e.g., masked, before the deposition or application of the coating 25. This can be avoided by depositing the coating 25 after the material-to-metal bond is formed. The arrangement, e.g.,The collar 16 being spaced apart from the cooling structure can help to avoid having to remove the coating 25 in the connecting areas, since the collar 16 can be arranged outside the area of the cooling structure to be coated.

[0071] The coating 25 can, for example, have a layer thickness between 1 µm and 500 µm.

[0072] The forming of the preform 19 can be carried out in one or more stages, so that the cooling elements 6 and the base element 4 or the bottom element 10 or the cover element 11 can be formed in one or more steps.

[0073] According to one embodiment variant, it is further possible for at least some of the cooling elements 6 to be connected to both the base element 10 and the cover element 11. For this purpose, for example, the base element 10 or the cover element 11 can be heated from the outside in the contact area of the cooling element 6 to be connected, e.g. with a laser. The area to be heated can be a maximum of the size of the cross-section of the cooling element 6 in the cooling element head 7. For example, a circular or annular region of the material connection between the cooling element 6 and the base element 10 or the cover element 11 can be formed.

[0074] In order to be able to provide a filler material for this material connection of the cooling element 6 to the base element 10 or the cover element 11, it can be provided according to one embodiment that joining recesses 26 (joining depressions) are formed in cooling element heads 7 of the cooling elements 6, which are connected to both the base element 10 and the cover element 11, as shown in Fig. 1 is indicated by dashed lines. The joining recesses 26 can be formed, for example, during the forming of the preform 19 into the cooling elements 6, for example by the mold 20 for forming the cooling elements 6 with the joining recess 26 not having an opening, but only a depression with a corresponding contour of the bottom of the depression for forming the joining recess 26. A filler material, e.g., a solder, can be arranged in the joining recesses 26. This can be liquefied, for example, by laser or induction. Sinter-soldering of the cooling element 6 is also possible with this.

[0075] In addition to the formation of the material connection between the base element 10 and the cover element 11, a positive connection can also be provided by forming corresponding positive locking elements (e.g. in the form of a tongue and groove connection) in the base element 10 and / or in the cover element 11.

[0076] Furthermore, it can be provided that the inlet element 12 and / or the connection element 13 are arranged in a side wall of the cooling device 1.

[0077] As from Fig. 3, the base element 10 can be manufactured with openings 27, via which the cooling device can be connected to the component 2 to be cooled, for example by screwing.

[0078] The specific shape of the cooling device 1 shown in the figures serves only to illustrate the invention. The cooling device 1 may also have a different shape.

[0079] The exemplary embodiments show possible embodiments, whereby it should be noted at this point that combinations of the individual embodiments are also possible.

[0080] For the sake of clarity, it should finally be pointed out that for a better understanding of the structure of the cooling device 1, it is not necessarily shown to scale. List of reference symbols 1 cooling device 2 component 3 Back 4 Basic element 5 Surface 6 Cooling element 7 Cooling element head 8 Height 9 Deepening 10 floor element 11 Cover element 12 Inlet element 13 Outlet element 14 space 15 Joint gap 16 collars 17 Side wall 18 element height 19 Preform 20 mold tool 21 perforated plate 22 Recess 23 Recess 24 stamps 25 Coating 26 joining recess 27 Breakthrough 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] DE 10 2019 108 106 A1

[0003] DE 10 2018 216 859 A1

[0004]

Claims

[1] Method for producing a cooling device (1) with a base element (10) and a cover element (11) connected thereto, wherein a cooling structure with cooling elements (6) is arranged between the base element (10) and the cover element (11), comprising the steps of providing a material and forming a cooling structure from the material, characterized by that a sintering powder is used as the material, from which at least one green compact is produced by pressing, that the green compact is sintered to form a preform (19), and from the preform (19) the cooling structure in the form of cooling elements (6) is produced by forming, for which purpose a part of the preform (19) is pressed through a forming tool (20), and that after the cooling structure has been arranged between the base element (10) and the cover element (11), the base element (10) is materially connected to the cover element (11). [2] Method according to claim 1, characterized bythat the base element (10) is / are produced from at least one preform (19) and / or the cover element (11) is / are produced from at least one preform (19). [3] Method according to claim 2, characterized by that cooling elements (6) of the cooling structure are formed integrally with the base element (10) and / or that cooling elements (6) of the cooling structure are formed integrally with the cover element (11). [4] Method according to one of claims 1 to 3, characterized by that the material connection is formed outside the area of the cooling structure. [5] Method according to claim 4, characterized by that a joining gap (15) is formed in the base element (10) or in the cover element (11). [6] Method according to one of claims 1 to 5, characterized by that the material connection is formed as a soldered connection. [7] Method according to claim 6, characterized by that the solder connection is made by inductive soldering or sinter soldering. [8] Method according to one of claims 1 to 7, characterized by that at least some of the cooling elements (6) are connected to both the base element (10) and the cover element (11). [9] Method according to claim 8, characterized by that joining recesses (26) are formed in cooling element heads (7) of the cooling elements (6), which are connected to both the base element (10) and the cover element (11). [10] Method according to one of claims 1 to 9, characterized by that a coating (25) is applied to the cooling structure. [11] Method according to claim 10, characterized by that the coating (25) is carried out before or after the material-locking connection of the base element (10) to the cover element (11). [12] Cooling device (1) comprising a base element (10) and a cover element (11) connected thereto, wherein a cooling structure with cooling elements (6) is arranged between the base element (10) and the cover element (11), characterized by that the cooling structure is made of a formed sintered material and that the base element (10) is integrally connected to the cover element (11). [13] Cooling device (1) according to claim 12, characterized by that cooling elements (6) of the cooling structure are formed integrally with the base element (10) and / or cooling elements (6) of the cooling structure are formed integrally with the cover element (11). [14] Cooling device (1) according to claim 12 or 13, characterized by that the material connection between the base element (10) and the cover element (11) is a solder connection. [15] Cooling device (1) according to claim 14, characterized bythat the solder connection is formed in a joining gap (15), wherein the joining gap (15) is formed outside the cooling structure.

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