Method for producing cooling device

Abstract

The invention relates to a method for producing a cooling device (1), comprising the steps of providing a material and constructing a cooling structure from the material, using a metal powder as the material, producing a green body from the powder by means of metal powder injection molding or by an additive method, sintering the green body into a shaped blank (18), and cooling the shaped blank (18). And producing the cooling structure in the form of a cooling element (6) from the parison (18) by means of press forming, for which purpose a part of the parison (18) is pressed by means of a forming tool (19) or into a forming tool, or a green body is produced from the powder by means of pressing, the green body is sintered into the parison (18), and the cooling structure is produced in the form of a cooling element (6) from the parison (18) by means of press forming. And producing the cooling structure with a cooling element (6) by means of sintering forging.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a cooling device, the method comprising the steps of providing a material and constructing a cooling structure from the material. Background Art

[0002] So-called power electronic components, such as power semiconductors, are well-known from the prior art. Such components are frequently used, for example, also in motor vehicles. It is also known that these components generate a large amount of heat during operation, which usually has to be dissipated by means of a cooling medium. For this purpose, very different coolers are known in the prior art. Additionally, so-called pin-fin cooling bodies are also known, which are surrounded and flushed by a cooling medium and thus transfer heat from the pins to the cooling medium. For example, DE102019108106A1 describes a cooler for a power semiconductor in an inverter. The cooler is designed in two parts and includes: a bottom plate as a first part, which is thermally conductively attached to the power semiconductor; and a cooling body as a second part, which is arranged on the bottom plate. The cooling body has at least one corrugated void portion, which is constructed continuously from the side of the cooling body facing away from the bottom plate to the side facing the cooling body. The first part and the second part are connected to each other and are coated with a layer that protects the two parts from electrochemical reduction.

[0003] DE102018216859A1 discloses a device for cooling a component, which has: a first substrate and a second substrate; a columnar and / or conical first cooling rib constructed in the first substrate, which can be circulated by a coolant; and a columnar and / or conical second cooling rib constructed in the second substrate, which can be circulated by a coolant. The second substrate is joined to the first substrate such that the second cooling ribs are located between the first cooling ribs without contacting the first substrate. Summary of the Invention

[0004] The object of the present invention is to be able to manufacture a cooling device for a component in a resource-saving manner.

[0005] The object of the present invention is solved by the method mentioned at the beginning. According to the method, it is provided that a metal powder is used as the material, a green body is manufactured from the powder by means of metal powder injection molding or by means of an additive method, the green body is sintered into a shaped body, and the cooling structure in the form of a cooling element is manufactured from the shaped body by compression molding. For this purpose, a part of the shaped body is pressed or pressed into a molding die by a molding die, or a green body is manufactured from the powder by pressing, the green body is sintered into a shaped body, and the cooling structure having a cooling element is manufactured by means of sinter forging.

[0006] It is advantageous here that manufacturing the basic element as a cooling element does not generate waste for its production, as is the case, for example, in machining. Furthermore, all cooling elements of the cooling device can be manufactured simultaneously, whereby a corresponding increase in productivity can be achieved. Here, it is advantageous for the shaping that, although the preform already has the corresponding strength due to sintering, the preform can still be shaped more simply due to the pores compared to solid material. Furthermore, different complex shapes can be manufactured relatively quickly by means of metal powder injection molding or by means of additive methods for manufacturing the preform, and additive methods are particularly suitable for small batches.

[0007] According to an implementation variant of the invention, it can be provided that the preform is recompressed and the cooling structure is constructed during this recompression. By combining these steps into a single method step, a corresponding shortening of the manufacturing time of the cooling device can be achieved. It is advantageous here that, by not performing the recompression of the preform in advance, the shaping of the preform into the cooling structure can be carried out more simply due to the higher pore fraction.

[0008] According to another implementation variant of the invention, it can be provided that the cooling structure is manufactured in the form of pin-shaped cooling elements by using a perforated plate as a forming die. Thus, the forming die can be designed relatively simply. Furthermore, the forming die can be easily adapted to cooling elements of different shapes. Unexpectedly, despite the large contact surface, demolding the cooling element by pulling out the perforated plate does not cause problems such as material rupture.

[0009] According to another implementation variant of the invention, it can be provided that the surface of the preform with the cooling structure is manufactured at least partially arched. Thus, an improved "flow characteristic" of the material for manufacturing the cooling structure can be achieved.

[0010] Preferably, the cooling element is manufactured on a basic element, and the basic element is manufactured to have a back side. Thus, a one-piece structure of the cooling device can be manufactured.

[0011] Here, according to an implementation variant of the present invention, it can be stipulated that the base element has a maximum element height of 3 mm. Advantageously, compared with known cooling devices, the small element thickness (also referred to as element height) of the base element can improve heat exchange through a smaller thermal resistance. Such a small plate thickness cannot be manufactured using traditional processes or can only be manufactured at high cost because traditional processes use cutting methods. However, for cutting, the cooling plate must have a certain minimum thickness to be able to be cut. On the other hand, the materials used in traditional methods have higher stiffness compared to sintered materials of the same composition, which has an adverse effect on shaping. These limitations can be avoided using the method according to the present invention, and thus a cooling device with a base element having a smaller element thickness can also be manufactured.

[0012] According to an implementation variant of the present invention, in order to improve the flexural strength of the base element, at least one reinforcing element can be provided. The reinforcing element is preferably provided on the first surface of the base element, and the cooling element is also located on the first surface. Thereby, an additional effect can be achieved such that the reinforcing element can further improve the cooling performance of the cooling device.

[0013] According to another implementation variant of the present invention, it can be stipulated that the back side of the base element is configured with a bending portion, so that the base element has prestress. Advantageously, by pre-tightening or bending the base element, warping that may occur during the soldering process of the power electronic device or the component to be connected to the cooling device can be avoided, or conversely, deformation or tension caused by temperature effects in the cooling device can be avoided. Therefore, a reduction in the contact surface between the cooling device and the power electronic device or the component and the associated performance degradation can be avoided. Compared with other methods, the configuration of the bending portion can be simply incorporated into the existing process steps, so that no additional process steps are required for its manufacture, such as machining the contact surface between the base element and the power electronic device or the component.

[0014] According to another implementation variant of the present invention, it can be stipulated that at least one auxiliary element is provided on the back side for establishing a material locking connection between the cooling device and the component to be cooled by the cooling device. With the aid of this auxiliary element, the configuration of the material locking connection can be better defined, and thus the cooling device can also be made to fit snugly over the entire surface of the power electronic device or the component, thereby improving heat dissipation. Here, the auxiliary element can be manufactured during the process of constructing the cooling element or the preform.

[0015] According to another embodiment variant of the present invention, it can be provided that the dorsal bending part is manufactured with a plurality of different radii of curvature, so that the cooling device can be better adapted to different material locking connection methods. At the same time, therefore, the cooling device can also be pre-tightened only locally (more highly), whereby the influence of pre-bending on the material of the cooling device can be reduced.

[0016] Furthermore, the present invention relates to a device for manufacturing a cooling structure of a cooling device, which is particularly used for implementing the method according to the present invention. The device includes a supply device for supplying materials for constructing the cooling structure, an injection molding device or an additive manufacturing device for injection molding or additively manufacturing a green body from metal powder used as the material, a sintering device for sintering the green body into a molded body, and a pressing device for pressing the molded body into the cooling structure in the form of a cooling element. The pressing device has a forming die.

[0017] According to an embodiment variant of the present invention, it can be provided that the device further includes a recompression device for recompressing the molded body.

[0018] According to another embodiment variant of the present invention, it can be provided that the forming die is a perforated plate for manufacturing the cooling structure in the form of a pin-shaped cooling element. Description of the Drawings

[0019] For a better understanding of the present invention, the present invention will be explained in detail with the aid of the following drawings.

[0020] In highly simplified schematic diagrams respectively:

[0021] Figure 1 A side view of a cooling device with a component to be cooled is shown;

[0022] Figure 2 An axonometric view of the cooling device is shown;

[0023] Figure 3 A side view of an embodiment variant of the cooling device is shown;

[0024] Figure 4 A partial top view of another embodiment variant of the cooling device is shown;

[0025] Figure 5 A partial top view of another embodiment variant of the cooling device is shown;

[0026] Figure 6 A side view of an embodiment variant of the cooling device is shown;

[0027] Figure 7 A bottom view of another embodiment variant of the cooling device is shown;

[0028] Figure 8 Bottom perspective view showing another implementation variant of the cooling device;

[0029] Figure 9 Shows an implementation variant of the preform;

[0030] Figure 10 Shows an implementation variant of the molding die for manufacturing the cooling device. Detailed implementation

[0031] First of all, it should be noted that in the different described embodiments, the same components are provided with the same reference numerals or the same component names, and the disclosure contained in the entire specification can be meaningfully transferred to the same components with the same reference numerals or the same component names. The position descriptions selected in the specification, such as above, below, lateral, etc., also refer to the directly described and shown drawings, and these position descriptions are meaningfully transferred to the new positions when the positions change.

[0032] In Figure 1 a side view of the cooling device 1 is shown.

[0033] The cooling device 1 is used to cool a component 2 or multiple components 2 or an assembly. For this purpose, the cooling device is in the back side, especially directly in contact with at least one component 2, so for heat exchange it is preferably in direct contact with the component 2.

[0034] The component 2 is preferably an electronic component, especially a so-called power electronic component or a high-power electronic component or a power semiconductor or a high-power semiconductor, but it can also be implemented differently. Such a component 2 or an assembly composed of these components 2 or having these components can especially be set for power in the range from several kilowatts to megawatts. Such a component 2 is used, for example, to convert electrical energy using switching electronic components. Typical applications are converters or frequency converters in the field of electric drive technology, solar inverters for regenerating energy grids or switching power supplies (usually converting AC voltage to DC voltage through a rectifier and converting DC voltage to AC voltage through an inverter), and converters for wind turbines, such as control systems, battery management systems, etc. in the drive technology of the electric drive system of electric vehicles or hybrid vehicles. Power electronic components can be semiconductors, especially so-called power semiconductors, such as IGBTs.

[0035] Since such components 2 are themselves known from the relevant prior art, to avoid repetition of details, reference is made to these prior arts.

[0036] The cooling device 1 includes a base element 4, which can also form the back side 3 of the cooling device 1, and which has a cooling structure on a first surface 5, or the cooling device is composed of the base element 4 and the cooling structure. The cooling structure is formed by cooling elements 6, which are arranged on the base element 4 protruding from the first surface 5 and are integrally connected to the base element, as can also be seen from Figure 2 as shown. In other words, the cooling device can consist of only one single component. Regardless of this unity, within the scope of the present invention there is the possibility that for each component 2 or an assembly consisting of at least one such component 2 or having at least one such component 2, a plurality of cooling devices 1 according to the present invention can be combined with each other to form a cooling device group. Thus, the cooling device 1 can in particular also be modularly assembled into a cooling device group.

[0037] The base element 4 and the cooling elements 6 are made of sintered material or are manufactured or formed by / using metal powder. Additionally, the cooling elements 6 are manufactured by forming from the base element 4.

[0038] According to an implementation variant, the density of the base element 4 and the cooling elements 6 is at least 98%, in particular at least 98.5%, preferably at least 99% of the solid density of the material used.

[0039] Here, the solid density refers to the density of a cooling device manufactured by melting and metallurgy from the same material, i.e., a component composed of solid material. The solid material here refers to a metal material without pores except for defects, as it usually exists in sintered components.

[0040] The cooling elements 6 are arranged for circulation of a cooling fluid, such as water, so that the heat received by the cooling device 1 is dissipated via this cooling fluid. Preferably, the cooling device 1 is a so-called pin-fin cooling device.

[0041] The cooling elements 6 of the shown implementation variant are configured cylindrically. However, the cooling elements can also have different shapes, such as a frustoconical shape or generally a shape with a cross-section tapering in the direction of the cooling element head 7, such as a truncated pyramid shape.

[0042] The cross-section of the cooling elements 6 can be circular, elliptical, rhombic, square, etc.

[0043] Additionally, all the cooling elements 6 can be configured identically. However, cooling elements 6 with different shapes can also be arranged or combined on the base element 4.

[0044] The height 8 of the cooling elements 6 above the first surface 5 of the base element 4 is preferably between 2 mm and 20 mm.

[0045] In the simplest design of the cooling device 1, all the cooling elements 6 of the cooling device 1 have the same height 8 within the tolerance range. However, within the scope of the present invention, there is a possibility that the height of a part of the cooling elements 6 can be smaller than the height of the remaining cooling elements 6, as can be seen, for example, from Figure 3 . The edge cooling elements 6 can, for example, be higher than the remaining cooling elements, or the cooling elements 6 can have a trend from a height that is lower or higher in the center of the cooling device 1 to a height that is higher or lower at the edge of the cooling device 1. Other embodiments with different heights 8 are possible within the scope of the present invention.

[0046] Furthermore, it can be stipulated that: on the first surface 5 per dm 2 300 to 1300, in particular 300 to 1000, for example 300 to 750 cooling elements 6 are provided or configured. In particular, this quantity has proven to be advantageous in the manufacture of the cooling device 1, that is, in the shaping of the base element 4 into the cooling elements 6, because in this way damage to the cooling elements 6 or incompletely formed cooling elements 6 can be avoided or reduced.

[0047] As can be seen in particular from Figure 1 , according to an implementation variant of the cooling device 1, the back side 3 of the base element 4 is configured with a flat surface. However, there is also a possibility that the back side 3 is configured with one or more recesses 9 in which the component 2 is at least partially received. Thus, a better engagement of the component 2 to the cooling device 1 can be achieved. Generally, the component 2 can be connected to the cooling device 1, for example, by adhesion or screwing or soldering or sintering, etc.

[0048] Within the scope of the manufacture of the cooling elements 6, the at least one recess 9 can be manufactured simultaneously with the cooling elements. Via the at least one recess 9, it is also possible to manufacture cooling elements 6 with a height 8 greater than the height of the remaining cooling elements 6.

[0049] As can be seen from Figure 2 , the cooling device 1 can have at least one additional structural element 10 on the first surface 5 of the base element 4. The structural element 10 is a cylinder in the shown shape, but can also have other cross-sections, for example, a rhombic cross-section. With the structural element 10, another surface can be provided on the cooling device 1 that is above the plane of the cooling elements 6. Therefore, the height of the structural element 10 can be greater than the height of the cooling elements 6. However, it is also possible that the height of at least one structural element 10 is less than or equal to the height of the cooling elements 6. In addition, more than one structural element 10 can be provided, and the plurality of structural elements 10 can be configured the same or differently, for example, in terms of shape and / or height.

[0050] The structural element 10 can be provided, for example, as a reinforcement, a spacer or a stop for a threaded connection.

[0051] Preferably, the structural element 10 is not machined again mechanically, but rather the structural element is pressed together or manufactured powder metallurgically or by means of the method according to the invention in a net shape or near-net shape quality when pressing the preform for manufacturing the cooling device 1. Thus, the structural element 10 is preferably constructed integrally with the base element 4 and the cooling element 6.

[0052] In Figure 3 the illustrated embodiment variant, a reinforcement element 11 is provided on each end side between the cooling element 6 along the wide side of the base element 4. Figure 4 shows a partial view of a variant embodiment of the cooling device 1, in which the reinforcement element 11 is arranged continuously in a surrounding manner on the periphery of the base element 4. As can be seen from this Figure 4 it can also be seen that the reinforcement element 11 can be arranged directly on the edge of the base element 4. It can be seen from Figure 3 that: the reinforcement element 11 can also be arranged at a distance from the edge of the base element 4.

[0053] Furthermore, the reinforcement element 11 according to Figure 4 is rounded in the corner region of the base element 4. However, it can also be implemented in a different way, for example, following an inclined course relative to the edge or corner of the base element 4.

[0054] In Figure 4 the reinforcement element 11 is arranged between the edge and the cooling element 6. As indicated by the dashed line in Figure 1 the one reinforcement element 11 or a plurality of reinforcement elements 11 can also be arranged between the cooling elements 6, for example, can also be arranged only between the cooling elements 6. However, with regard to the reinforcement element 11, it is also possible according to Figure 1 and Figure 3 or Figure 4 a combination of the illustrated embodiment variants, so that the reinforcement element 11 can be arranged along the edge of the base element 4 and arranged between the cooling elements 6.

[0055] The reinforcement element 11 can have a straight course (as shown, for example, in Figure 2 ) or according to an embodiment variant can also have a non-straight, for example, wavy course (as Figure 5 a partial view of the cooling device 1 in shows this). These wavy-shaped reinforcement elements 11 can also be arranged extending between the cooling elements 6. However, in Figure 5In the exemplary embodiment shown, the wavy reinforcing element 11 simultaneously forms the cooling element 6 of the cooling device 1. Here, according to another exemplary embodiment, it may also be provided that the reinforcing element 11 having a longitudinal extension dimension is arranged at least approximately along the flow direction for the cooling fluid to pass through the cooling device 1. This may also be provided in other exemplary embodiments of the cooling device 1, i.e., not limited to the exemplary embodiment according to Figure 5 In the exemplary embodiment shown in Figure 5 channels for the cooling fluid are formed between the reinforcing elements 11.

[0056] Preferably, the reinforcing element 11 is lower than the cooling element 6, especially if the reinforcing element does not simultaneously also form the cooling element 6. Here, according to another exemplary embodiment, it may be provided that the reinforcing element 11 has a height 12 which corresponds to 20% to 100%, especially 60% to 90%, of the height 8 or, when the cooling element 6 has different heights, the maximum height 8 in the same direction as the cooling element 6.

[0057] The width of the reinforcing element 11 (parallel to the first surface 5 of the base element 4) can be between 0.5 mm and 4 mm.

[0058] In principle, the reinforcing element 11 can be installed on the base element 4 afterwards, for example after the cooling element 6 has been formed. However, according to one exemplary embodiment, the reinforcing element 11 can be manufactured when producing the blank for manufacturing the cooling device 1. According to another exemplary embodiment, the reinforcing element 11 can be manufactured from sintered material by shaping the material of the base part 4, preferably simultaneously with manufacturing the cooling element 6 from the blank.

[0059] Therefore, the one or more reinforcing elements 11 are preferably constructed integrally with the base element 4 and the cooling element 6. It is also preferred that the one or more reinforcing elements 11 are manufactured with a net shape or near-net shape quality.

[0060] The base element 4 can have an element height 13 between 1 mm and 5 mm. According to one exemplary embodiment, the base element 4 can have a maximum element height 13 of 3 mm. The base element 4 can especially have an element height 13 between 1 mm and 2.5 mm. The element height 10 of the (plate-shaped) base element 4 is measured between its back side 3 and the first surface 5. If a recess 9 is provided in the back side 3, the element height 13 is measured next to the recess 9.

[0061] In Figure 6The side view of an exemplary variant of the cooling device 1 is shown. Additionally, this cooling device has a base element 4, on the first surface 5 of which a cooling structure is provided, which has cooling elements 6.

[0062] Different from the exemplary variant of the cooling device 1 according to Figure 1 in the exemplary variant of the cooling device 1 according to Figure 6 in this exemplary variant, the back side 3 of the base element 4 is provided with a bend, by means of which the base element 4 is pre-tensioned.

[0063] In the exemplary variant shown, the bend is configured with a concave course with respect to the cooling element 6. The base element 4 can in particular be configured as flat-concave. The first surface 5 can be configured at least approximately following the course of the back side 3.

[0064] The second surface 3 or the entire base element 4 can also have a convex bend with respect to the cooling element 6.

[0065] The bend can be configured in the course of the length or width of the base element 4.

[0066] The bend can be configured with a constant radius of curvature 14 over the entire course. According to another exemplary variant, it can be provided that: the bend has a plurality of different radii of curvature 14. In particular, it can be provided that: the base element 4 has bends with the smallest radius of curvature 14 in the mutually opposed edge regions 15, 16.

[0067] Preferably, the bend is configured symmetrically in the course from the first edge region 15 to the second edge region 16.

[0068] The bend can for example have a course such as an ellipse, a parabola, etc. Other course shapes are likewise possible.

[0069] The cooling elements 6 can be arranged on the bent base element 4 with the same orientation. However, the orientation of the cooling elements 6 can also be arranged following the course of the bend of the base element 4. If the base element 4 reduces the bend and in particular configures the base element as a flat base element 4, this orientation can be changed during the formation of a material-locking connection with the component 2 by stress relief in the base element 4 due to the acting heat.

[0070] There is also the possibility that the height 8 of the cooling elements 6 is adapted to the bent course, so that the cooling element heads 7 are at the same height when the base element 4 has a bend.

[0071] The radius of curvature 12 of the base element 4 can be selected from the range of 250 mm to 5000 mm, in particular from 1000 mm to 4000 mm. Thus, a maximum deflection of 1.25 mm can be achieved over a length of 100 mm or 200 mm. For the case where the bent portion has a plurality of different radii of curvature 12, all radii of curvature 12 are likewise preferably selected from this range.

[0072] In Figure 7 a bottom view of another exemplary embodiment of the cooling device 1 is shown.

[0073] It should be mentioned here that the exemplary embodiments of the cooling device 1 described for the drawings can be used independently of one another. Similarly, combinations of these exemplary embodiments are possible. Thus, when the base element 4 is hereinafter referred to as being flat, this base element can also be curved, for example.

[0074] In Figure 7 the back side 3 of the base element 4 can be seen. At least one auxiliary element 17 is provided on this back side 3 for establishing a material-locking connection between the cooling device 1 and the component 2. In the specifically shown exemplary embodiment, the auxiliary element 17 is a recess. However, the auxiliary element 17 can also be a projection on the back side 3, as shown in the exemplary embodiment according to Figure 8 .

[0075] The recess is used to accommodate additional material for material locking and to prevent the molten additional material from flowing away / draining out during the construction of the material-locking connection between the cooling device 1 and the component 2 (see Figure 1 ).

[0076] Conversely, the projection is used to create in particular a uniform gap between the cooling device 1 and the component 2, such that the additional material is constructed with at least a substantially uniform layer thickness via the connection surface (the surface to which the additional material is applied), such that there is preferably no difference in terms of the thermal resistance between the cooling device 1 and the component 2 via the connection surface.

[0077] In Figure 7 only one auxiliary element 17 is shown. However, more than one auxiliary element 17 can also be provided, for example two, three, four, etc., as can be seen from Figure 8 . However, the number of auxiliary elements 17 specifically shown in Figure 8 should not be understood restrictively for the present invention. In particular, the number of the auxiliary elements can depend on the size of the base element 4.

[0078] In addition, the plurality of auxiliary elements 17 is not limited to the projections. A plurality of discrete recesses distributed on the back side 3 can also be provided as the auxiliary elements 17.

[0079] Within the scope of the present invention, it is also possible for the combination of the recess and the protrusion to be an auxiliary element 17 on the back side 3 of the basic element 4.

[0080] The recess can be configured in a circular, oval, egg-shaped, approximately circular, triangular, quadrangular, pentagonal, etc. shape when observed in a top view. More complex shapes are also possible, as can be seen from the examples of the recesses in Figure 7 .

[0081] The recess can have a maximum depth between 0.05 mm and 0.5 mm. Below 0.05 mm, errors are more likely to occur in the connection formation of the recess because the recess may not be filled / filled with additional material. With a depth greater than 0.5 mm, the gap between the cooling device and the component with a material-locking connection may change too much, thus possibly not forming a uniform connection layer.

[0082] Preferably, when there are multiple recesses in the back side of the basic element 4, all the recesses are configured identically. However, it is also possible to provide multiple recesses with different configurations.

[0083] The at least one protrusion can have a maximum height between 0.05 mm and 0.5 mm. As in the case of the recess, a height less than 0.05 mm may result in too small a gap thickness to form a uniform connection layer. On the other hand, with a height greater than 0.5 mm, the connection layer may be constructed too thick, thereby possibly deteriorating heat dissipation. In addition, when the gap thickness is greater than 0.5 mm, the liquid filling material may flow out from the connection area, thus posing a risk of forming a non-uniform connection layer.

[0084] When there are multiple protrusions, all the protrusions can be configured identically. Similarly, protrusions with different configurations can be provided on the back side 3 of the basic element 4.

[0085] The protrusion can be configured in a granular, tabular, etc. shape. The protrusion can, for example, have a cross-section such as a circle, egg shape, oval, approximately circular, triangle, quadrangle, etc. in a top view.

[0086] The protrusion can have a length between 5 mm and the total length of the basic element 4. Additionally, the protrusion can have a width between 5 mm and the total width of the basic element 4.

[0087] The recesses can altogether have a surface extension dimension between 0.1% and 50% of the surface of the second surface 3 of the basic element 4.

[0088] The connection layer between the cooling device 1 and the component 2 can have a layer thickness between 0.01 mm and 0.5 mm.

[0089] The at least one auxiliary element 17 can also be produced by powder metallurgy or by means of the method according to the invention and can be formed integrally with the base element 4. For example, the at least one auxiliary element 17 can be produced during the formation of the cooling element 6.

[0090] For the production of the cooling device 1, sintering powders or (in particular metal) powders used in powder metallurgy or powders in general are used. Preferably, metal powders with correspondingly good thermal conductivity are used. In particular, powders based on aluminum or aluminum alloys or based on copper or copper alloys or MMC powders (metal matrix composites) are used.

[0091] The production of the cooling device can be carried out in a powder metallurgical manner according to the powder metallurgy method, so that the cooling device 1 can thus be a sintered component. For this purpose, a green body can be produced in a corresponding die (die) from a powder that can be produced from individual (metal) powders by mixing, with powdery auxiliary agents such as, for example, a binder, which powder can be used in a pre-alloyed form if necessary. The density of the green body is preferably at least 80%, in particular between 80% and 96%, of the solid density of the material.

[0092] However, the green compact can also be manufactured in another way. In particular, the green compact can be manufactured by means of metal powder injection molding (MIM method) or by means of an additive method. For example, each of the additive methods known to date, such as laser powder bed melting, selective laser sintering, electron beam powder bed melting, selective laser sintering, binder jetting, direct energy deposition, mold jetting method, fused deposition molding, stereolithography method and other methods can be used to manufacture the green compact. Preferably, a cold metal melting method (CMF method) is used as an additive method. Since these methods are known per se, reference is made to the relevant prior art for further details thereon.

[0093] The green body is then dewaxed at room temperature and subjected to one-stage, two-stage or multi-stage sintering and then preferably cooled to room temperature. The sintering can be carried out at a temperature between 500° C. and 1300° C., for example.

[0094] Since the sintering of metal green bodies and the method parameters used therein are likewise known from the prior art, in order to avoid repetitions, reference is made to the relevant prior art in this regard.

[0095] By sintering, a preform 18 is formed from the green body, as is exemplified in Figure 9 The preform 18 can be designed as a flat plate, so that the rear side 3 and the first surface 5 can extend parallel to one another.

[0096] According to an implementation variant of the method, it can be stipulated that the first surface 5 of the preform 18 is manufactured at least partially arched, and the cooling structure is constructed on this first surface. Given the improved formability of the preform 18, other shapes of the first surface of the preform 18 are possible. Therefore, it is already possible to preform a first pin-fin addition or a cooling element addition (circular, oval, elliptical, etc.) with a height between 0.1 mm and 2.0 mm. Additionally, structures (waves, ribs, etc.) can be intentionally introduced into the first surface 5 of the preform 18 to increase the eddy current of the cooling fluid if necessary.

[0097] Subsequently, the preform 18 can be recompressed. However, the recompression is preferably carried out simultaneously with the forming of the preform 18 into the cooling element 6.

[0098] The forming of the preform 18 is carried out in a forming die 19. For this purpose, the preform 18 is placed into the forming die 19 or the preform is abutted against the forming die. In the simplest case, the forming die 19 consists of a perforated plate 20. The perforated plate 20 has voids 21, in particular through-holes, and a part of the material of the preform 18 is pressed into or through these voids, thereby forming the cooling element 6. The remaining part of the material of the preform 18 that is not pressed into or through the forming die 19 forms the base element 4.

[0099] The voids 21, i.e., their cross-sections, are correspondingly adapted to the cross-section of the cooling element 6 to be manufactured.

[0100] The forming die 19 can also have a different appearance, i.e., it does not necessarily have to be a simple perforated plate 20. In particular, the forming die 19 can be constructed "pan-shaped" as a female die.

[0101] For the case where there is at least one additional structural element 10, this additional structural element can be considered through corresponding voids or corresponding through-holes in the forming die 19.

[0102] For forming, a punch 22 can be abutted against the back side 3 of the preform 18 and pressed against the preform 18 with a predeterminable pressure, and the back side also forms the back side 3 of the base element 4. The forming can be carried out, for example, at a pressure between 700 MPa and 1600 MPa. Additionally, the forming can be carried out within a time period of at most 10 seconds, especially between 0.1 second and 10 seconds. Additionally, the forming is preferably carried out at room temperature (20 °C), i.e., cold forming, or the forming can also be carried out after preheating the preform 18 to a temperature between 50 °C and 300 °C, for example, between 50 °C and 150 °C, and / or in or with a forming die 19 heated to a temperature between 50 °C and 300 °C, for example, between 50 °C and 150 °C.

[0103] As an alternative to this process, the preform 18 can also be formed into the base element 4 with the cooling element 6 by sinter forging. The temperature during sinter forging can be between 500 °C and 900 °C, and for this purpose, in particular, the preform 18 is heated to this temperature. As an alternative or in addition to this, the mold can also be heated to this temperature, and the preform 18 can be placed in the mold during sinter forging.

[0104] After the preform 18 is shaped, i.e., formed, the cooling device 1 can be completed. However, there is also the possibility of reprocessing the cooling device 1. For example, the height of the cooling element 6 can be calibrated or generally recompressed, and for this purpose, a punch can also be used. In addition, the first surface 5 and the cooling element 6 can be provided with a corrosion-resistant coating, for example, an electroplated Ni-P coating.

[0105] The at least one auxiliary element 17 can also be manufactured during the reprocessing. The auxiliary element can also be manufactured during powder pressing after sintering. In this case, the punch 22 must have corresponding voids or protrusions so as not to compress the auxiliary element 17 when forming the preform 18.

[0106] However, the at least one auxiliary element 17 can be manufactured additionally while forming the preform 18. For this purpose, the punch 22 can have protrusions for constructing the above-mentioned recesses in the back side 3 of the base element 4 and / or recesses 25 for constructing the above-mentioned protrusions on the back side 3 of the base element 4 on the abutting surface that can be applied to the preform 18. The number of protrusions and / or recesses on the punch 22 depends on the number of auxiliary elements 17 to be manufactured.

[0107] It can also be provided that: the at least one auxiliary element 17 is manufactured during the height calibration of the cooling element 6. For this purpose, the support surface of the mold or the clamping element has corresponding protrusions or recesses, and the base element 4 is placed on the support surface for height calibration.

[0108] It should be mentioned here that the forming of the preform 18 can be carried out in one stage or multiple stages. In a multi-stage embodiment, the cooling element 6 is not formed in one step but in multiple steps. In particular, in a multi-stage implementation variant, it can be advantageous to construct the auxiliary element 17 during the height calibration of the cooling element 6 when necessary.

[0109] The previously explained bending of the base element 4 can also be carried out during the forming of the preform 18 or during the height calibration of the cooling element 6 when necessary. For this purpose, it is only implicitly in Figure 7The bent abutment surface 23 of the punch 22 is shown by a dashed line. The bent portion of the abutment surface 23 is opposite to the bent portion to be manufactured of the base element 4. Therefore, no machining is required for constructing the bent portion of the base element 4.

[0110] The cooling device 1 can be arranged openly on the component 2 to be cooled. According to another embodiment variant, there is also the possibility that the cooling element 6 is arranged in a housing. In this case, the base element 4 can form the base element or the cover element of the housing. In particular, with the aid of the bottom element, the cooling device 1 can be arranged in a abutting manner, in particular in a directly abutting manner, on the component 2. Additionally, there is the possibility that the cooling element 6 is arranged on the bottom element and another cooling element 6 is arranged on the cover element, and the cooling element of the bottom element and the cooling element of the cover element together form the cooling structure. For this purpose, for example, the cooling element 6 of the cover element can be arranged in the gap between the cooling elements 6 of the base element. In this case, the base element with a part of the cooling elements 6 is manufactured from the preform 18 according to one of the methods mentioned above, and the cover element with the remaining cooling elements 6 is manufactured from another preform.

[0111] It should be mentioned here that although a method for manufacturing the cooling device 1 is claimed, the cooling device 1 itself can also be claimed separately, if necessary, independently of the manufacturing method.

[0112] The embodiments show possible embodiment variants. It should be noted here that combinations of the individual embodiment variants with one another are also possible.

[0113] Finally, it should be pointed out that, for a better understanding of the structure of the cooling device 1 or the molding die 19, they are not necessarily shown to scale.

[0114] List of reference numerals

[0115] 1 Cooling device

[0116] 2 Component

[0117] 3 Back side

[0118] 4 Base element

[0119] 5 Surface

[0120] 6 Cooling element

[0121] 7 Cooling element head

[0122] 8 Height

[0123] 9 Recess

[0124] 10 Structural element

[0125] 11 Reinforcing element

[0126] 12 Height

[0127] 13 Component Height

[0128] 14 Radius of Curvature

[0129] 15 Edge Region

[0130] 16 Edge Region

[0131] 17 Auxiliary Component

[0132] 18 Parison

[0133] 19 Molding Die

[0134] 20 Orifice Plate

[0135] 21 Void Portion

[0136] 22 Punch

[0137] 23 Contact Surface.

Claims

1. A method for manufacturing a cooling device (1), the method comprising the steps of providing a material and constructing a cooling structure from the material, characterized in that, A metal powder is used as a material, and a green body is manufactured from the powder by means of metal powder injection molding or by means of an additive method. The green body is sintered to form a shaped body (18), and the cooling structure in the form of a cooling element (6) is manufactured from the shaped body (18) by pressing. For this purpose, a part of the shaped body (18) is pressed through a shaping die (19) or pressed into the shaping die, or a green body is manufactured from the powder by pressing, the green body is sintered to form a shaped body (18), and the cooling structure having the cooling element (6) is manufactured by means of sinter forging.

2. The method according to claim 1, wherein The shaped body (18) is recompressed, and the cooling structure is constructed during the recompression.

3. The method according to claim 1 or 2, characterized in that, The cooling structure is manufactured in the form of a pin-shaped cooling element (6) by using an orifice plate (20) as the shaping die (19).

4. The method according to any one of claims 1 to 3, characterized in that, The surface of the shaped body (18) on which the cooling structure is constructed is manufactured at least partially arched.

5. The method according to any one of claims 1 to 4, characterized in that, The cooling element (6) is manufactured on a base element (4), and the base element is manufactured to have a back side (3).

6. The method according to claim 5, wherein The base element (4) has an element height (13) of at most 3 mm.

7. The method according to claim 5 or 6, characterized in that At least one reinforcing element (11) is provided on a first surface (5) of the base element (4) on which the cooling structure is provided.

8. The method according to any one of claims 5 to 7, characterized in that, The back side (3) of the base element (4) is constructed with a bend so that the base element (4) has prestress.

9. The method according to any one of claims 5 to 8, characterized in that At least one auxiliary element (17) is provided on the back side (3) for establishing a material-locking connection between the cooling device (1) and a component (2) to be cooled by the cooling device (1).

10. The method according to any one of claims 5 to 9, characterized in that, The bend of the back side (3) is manufactured with a plurality of different radii of curvature (14).

11. Apparatus for manufacturing a cooling structure of a cooling device (1), in particular for implementing the method according to any one of the preceding claims, characterized in that, The device includes a providing device for providing a material for constructing a cooling structure, an injection molding device or an additive manufacturing device for injection molding or additively manufacturing a green body from a metal powder used as a material, a sintering device for sintering the green body into a shaped body (18), and a pressing device for pressing the shaped body (18) into the cooling structure in the form of a cooling element (6), and the pressing device has a shaping die (19).

12. The device according to claim 11, characterized in that, The device further includes a recompression device for recompressing the shaped body (18).

13. The device according to claim 11 or 12, characterized in that, The shaping die (19) is an orifice plate (20) for manufacturing the cooling structure in the form of a pin-shaped cooling element (6).

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