Device having at least one electronic component and method for producing

Abstract

The invention relates to a device (20) having at least one electronic component (29, 30) and at least one housing assembly (21) made of a plastic material, the electronic component (29, 30) being connected to a metallic heat sink (35) for dissipating heat from the electronic component (29, 30), the heat sink (35) having a surface region (44, 45, 46) with a surface structure, and the housing assembly (21) being connected to the electronic component (29, 30). The heat sink (35) is connected, in particular in a force-fitting and / or form-fitting manner, to the at least one housing assembly (21) in the region of the surface structure.

Description

Technical Field

[0001] The invention relates to a device having at least one electronic component and a method for producing it. Background Art

[0002] DE 10 2016 209 950 A1 discloses a method for connecting two components, wherein a joining region of the surfaces of the components to be connected is heated by means of a radiation source, wherein the first component is made of plastic and the second component is made of metal. The heating enables the liquefied plastic material to penetrate into the structure of the metal surface, thereby producing a tight bite structure between the plastic material of the first component and the surface structure of the second metal component. In this way, a connection is achieved, which also enables the connection to be media-tight. In this case, the connection is particularly designed to be force-fitting and / or form-fitting. Summary of the invention

[0003] Advantages of the present invention.

[0004] The device with the features of the independent claim utilizes a form-locking and force-locking connection between a metal component and a plastic component in order to enable heat removal of the waste heat generated during the operation of the electronic component. Here, it is utilized that the connection of the plastic material to the structured metal surface not only exhibits a robust force-locking connection, but also can achieve good heat transfer from the metal to the plastic material by avoiding a heat-insulating air layer. Here, heat transfer is achieved in a good and uniform manner in the area of ​​the structured surface, so that the heat received by the cooling body from the electronic component can be well transferred to the housing component composed of the plastic material by a large area of ​​heat diffusion. It is therefore possible that the outer shell of the device is completely or at least partially composed of plastic material, and the heat generated in the interior of the device during the operation of the electronic component is transferred and diffused by the cooling body, and can be output through the form-locking connection and the housing. Therefore, by using plastic for the housing component, corresponding advantages can be utilized, such as, for example, various spatial design possibilities, electrical insulation and low weight, while nevertheless ensuring good heat removal.

[0005] Further advantages result from the dependent claims. It is thus advantageous to achieve a snap-fit ​​connection between the heat sink and the housing component by means of a joining process or an injection molding process, including special processes such as injection compression molding. This allows the material of the housing component to join well to the structuring of the surface area of ​​the heat sink, so that the surface can be formed as well as possible without air-filled defects / gaps, and thus the greatest possible heat conduction to the transition between metal and plastic can be achieved. At the same time, a stable and leaktight connection can be achieved.

[0006] It is also advantageous if the housing component is designed as an injection-molded part, since this allows for a wide variety of shapes and manufacturability of the housing component. The device can thus be easily adapted to different installation positions by a corresponding selection of the injection molding tool. In particular, thermoplastics with a low melt viscosity are used as plastic material in this case, in order to achieve good filling properties of deepenings with a large aspect ratio. In addition, plastics with low shrinkage values ​​are preferably used in order to reduce the risk of cavitation due to shrinkage during cooling.

[0007] It is also advantageous if the housing component has an opening toward the exterior of the device, so that the surface of the cooling body is accessible to the air flow through the opening. In addition to the heat conduction caused by or using the housing component composed of plastic, heat can also be additionally discharged by a direct air flow toward the cooling body. Due to the snap-fit ​​connection between the cooling body and the housing component, no additional seal is required, because the connection between the cooling body and the housing component is already designed to be sealed by suitable selection of the plastic material and the type of construction or geometry and control of the joining process.

[0008] A particularly high cooling effect is achieved if the heat sink has cooling ribs in the region of the opening so that the surface of the heat sink facing the air flow is increased. Arranging the cooling ribs in the openings makes it possible for the cooling ribs to not protrude beyond the openings and therefore beyond the device, and thus for the device to be designed in a compact manner.

[0009] Furthermore, it is advantageous if the housing component and the heat sink are connected to one another in such a way that they seal the interior of the device from the exterior, since additional seals can thereby be omitted and the connection between the housing component and the heat sink is already designed in such a way that it seals the interior.

[0010] Furthermore, in other embodiments, it is advantageous if the housing component completely covers the heat sink relative to the exterior of the device, thereby preventing or at least reducing external contact of metal with the exterior of the device, wherein heat from the operation of the electronic components can nevertheless be reliably dissipated to the exterior of the device due to the good thermal connection between the heat sink and the housing component.

[0011] It is also advantageous if the electronic components are arranged on a printed circuit board and the printed circuit board is arranged on the side facing away from the heat sink in the interior of the electronic device. The electronic components can be easily supplied with electrical energy and data can be easily removed from the printed circuit board by a corresponding arrangement on the printed circuit board. A space-saving design can be achieved by thermally dissipating heat on a heat sink arranged opposite the printed circuit board.

[0012] It is also advantageous if the electrical contacts for the printed circuit board or for the electronic components are arranged embedded in the housing component. This makes it possible to easily implement a lead-through for the plug on the outside. In addition, it is also possible to supply the printed circuit board with current without requiring additional insulation, since the plastic material of the housing component can already assume this insulation function.

[0013] It is also advantageous if the cooling body is shaped in such a way that it has not only a region with a structured portion parallel to the surface of the housing component, but also a surface parallel to the electronic component and an intermediate region connecting the two surface regions. Heat can be conducted from the interior of the device to the exterior of the housing component via the intermediate region. Furthermore, by means of a corresponding shaping of the cooling body, the stability of the device in its interior can be additionally ensured, in that forces acting on the housing component from the outside can be directed to a stable structure in the housing, such as, for example, an internal rib structure or a printed circuit board.

[0014] Furthermore, it is advantageous if the housing component covers the heat sink in such a way that a heat flow from the electronic component to the exterior of the device is possible via the heat sink and the housing component, since in this way the heat can be efficiently dissipated to the outside.

[0015] Corresponding advantages also result for a method for producing a device in which a housing component is produced from a plastic material and is connected to a metallic heat sink which has a structuring in a surface region so that a snap-fit ​​connection can be achieved between the structured surface region and the housing component.

[0016] It is also advantageous to melt the plastic material of the housing component in such a way that it embeds into the structure of the structured surface area of ​​the heat sink in order to achieve a snap-fit ​​connection. This also achieves a permanent prevention of corrosive attack in the joint interface, in particular due to thermal and / or weathering processes.

[0017] It is also advantageous to manufacture the housing component using an injection molding process, wherein the heat sink is completely or partially inserted into an injection molding mold and is heated, at least in the injection molding region for the duration of the overflow, to a temperature close to the grain melting temperature of the plastic used in the injection molding mold, so that at least a portion of the heat sink is injection molded using the plastic material of the housing component.

[0018] By connecting the heat sink to the electronic component, an advantageous thermal connection to the housing component can be achieved, wherein in one embodiment, a thermally conductive material can advantageously be arranged between the heat sink and the electronic component. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Embodiments of the invention are shown in the drawings and explained in more detail in the following description.

[0020] Figure 1 shows a cross section of a metal-plastic connection for connecting a cooling body to a housing component,

[0021] Figure 2 A first exemplary embodiment for a device having a housing component and a heat sink is shown in cross section.

[0022] Figure 3 The top view shows the Figure 2 The layout structure,

[0023] Figure 4 and Figure 5 A further exemplary embodiment for a device having a heat sink and a housing assembly is shown in a sectional illustration. DETAILED DESCRIPTION

[0024] exist Figure 1 An example of a connection between a housing component 11 and a metal cooling body 10 is shown, the housing component being, for example, made of a thermoplastic plastic material, in particular polyamide, PBT, PPS or polypropylene. The cooling body 10 has a surface structuring portion 12, by which the surface of the cooling body is enlarged. The surface structuring portion 12 can be implemented, for example, as a laser structuring portion, by which a structure in the range of 10 to 50 microns is produced on the surface of the metal cooling body. In this case, a moss-like, cauliflower-like or coral-like structure is produced, by which a very rough surface is produced, but in particular also a back-cut portion is produced in a feasible manner. In other embodiments, the surface can also be etched by an electromechanical method. For example, aluminum or copper can be used as a metal material for the cooling body 10.

[0025] By means of an adapted structuring process, the desired surface structuring can be adapted to the respective intended use, in particular empirically. In the metal-plastic transition shown in comparison with thermal contact rivets (so-called heat riveting), a significantly improved heat transfer can be demonstrated experimentally, which has a heat conduction effect that is up to 40 percent better, depending on the positioning of the measuring points between the heat sink and the plastic housing. At the same time, it was determined that thermal aging due to thermal shock loads during the thermal joining of the heat sink 10 and the housing component 11 does not lead to a deterioration of the connection properties, such as due to delamination or gap formation, for example.

[0026] exist Figure 2, a sectional view of a device 20 is shown, which has a housing, which is composed of a first housing component 21 and a housing component 22. Here, the second housing component 22 serves as a cover to close the first housing component 21 that forms an interior space 23. Here, the cover 22 seals the interior space 23 from the exterior space 24.

[0027] The first housing component 21 and preferably the cover 22 are also made of plastic material, in particular thermoplastic. A plug 26 is integrally formed with the first housing component at the outer side 25 of the first housing component 21, in the interior of which electrical contacts 27 are provided to receive a matching connection plug.

[0028] A printed circuit board 28 is arranged in the interior space 23. In the embodiment shown here, a first electronic component 29 and a second electronic component 30 are arranged on the printed circuit board, which are connected to the printed circuit board 28. Figure 2 The printed circuit board 28 is in turn connected to the electrical contacts 27 in the plug 26 via electrical connection contacts 31, wherein the electrical wires 32 are embedded in the plastic material of the first housing component 21. In the embodiment shown here, the printed circuit board 28 is latched at the thickening 33 of the connection contacts 31. The first housing component 21 has support elements 34, which support and stabilize the printed circuit board 28 and the connection contacts 31.

[0029] The first and second electronic components 29, 30 are thermally connected to the cooling body 35, so that the heat of the electronic component elements is output to the cooling body 35. For this purpose, the electronic components can be in direct pressure contact with the cooling body 35. In the embodiment shown here, the contact is achieved by a thermal interface material arranged between the cooling body 35 and the electronic components 29, 30, such as, for example, a thermally conductive paste.

[0030] The cooling body 35 is implemented as a heat conducting sheet, which is composed of aluminum or copper or another suitable metal, for example. The cooling body has a first area 38 parallel to the surface 39 of the second electronic component 30 and a second area 40 parallel to the first surface 41 of the first electronic component 29. The printed circuit board 28 and therefore the electronic components 29, 30 are also arranged at a distance 42 relative to the surface 43 of the first housing component 21.

[0031] Here, the heat sink 35 is designed in a serpentine manner to a certain extent, so that it first touches the surface 43 of the first housing component 21 in a first contact area 44, then bridges the distance 42 to the second electronic component 30, and then is followed by a first area 38 parallel to the surface 39 of the second electronic component, wherein the heat sink is then formed in such a way that it again bridges the distance 42. The heat sink now forms a second contact area 45, which contacts the first housing component 21. Thereafter, the heat sink is formed in such a way that it again bridges the distance 42 to the first electronic component 29 and leads to a second area at the first electronic component 29. The heat sink 35 is then formed in such a way that it again bridges the distance 42 and reaches the surface 43 of the first housing component 21 in a third contact area 46.

[0032] In the contact regions 44 , 45 , 46 , a contact is achieved between the metallic heat sink 35 and the plastic material of the first housing component 21 . Figure 1 The contact can be made, for example, such that a surface structure is first produced in the contact regions 44, 45, 46 of the heat sink 35 by means of a laser or chemical structuring method. The surface 43 of the first housing component 21 is then heated in the region in which the heat sink 35 is to be installed, for example by means of infrared radiation or by means of laser radiation. The heat sink 35 is then pressed onto the surface 43 of the housing component 21, so that the desired metal-plastic connection is produced in the contact regions 44, 45, 46, as described in accordance with the invention. Figure 1 As already explained.

[0033] In a subsequent working step, the printed circuit board 28 with the electronic components 29, 30 already mounted thereon can be mounted on the connecting contacts 31, wherein the electronic components 29, 30 are placed in a thermally conductive connection with the heat sink 35. For mechanical stabilization or to realize a further electrical contact, a further electrical contact 47 corresponding to the first electrical connecting contact 31 can be provided on the first housing component 21 and projecting into the interior 23, the further electrical contact being mounted on the printed circuit board 26 on the side of the first electrical connecting contact facing away from the plug 26. This further electrical contact 47 is also embedded in the plastic material of the first housing component 21.

[0034] exist Figure 3 The following is shown in Figure 22 without the cover 22. It is clear from this view that the further plug 48 can contact the printed circuit board 28 parallel to the first connecting contact 31 and be guided to a corresponding connection on the plug 26. Likewise, a further plug 49 can be arranged on the printed circuit board 28 parallel to the further electrical contact 47 on the side of the printed circuit board facing away from the plug 26 for stabilization purposes.

[0035] In this case, the device 20 can be used for any purpose, for which an electronic circuit should be provided, in which waste heat is generated and should be discharged to the outside. This can be, for example, a use scenario for any type of controller, such as, for example, a motor controller or a controller for a safety device in a motor vehicle. Data for processing can be introduced into the device 20 via a plug 26, and control data for components outside the control device can also be read out from the device 20, for example, by a data bus connection. The data are processed by electronic components 29, 30, which are, for example, configured as microprocessors or as system-on-chip systems. In this case, the waste heat generated is conducted to the first housing component 21 via a cooling body 35. In this case, it is utilized that the cooling body can conduct the generated heat well. Good heat transfer to the material of the first housing component 21 is also achieved via the contact areas 44, 45, 46, so that heat can be output to the external space 24 at the location where the cooling body 35 contacts the first housing component. The air flow or heat convection surrounding the device 20 can then therefore conduct the heat. As according to Figure 1 As explained, the particularly efficient thermal coupling by means of the metal-plastic connection achieves, on the one hand, good heat conduction and, on the other hand, does not lead to overheating of the plastic material of the first housing component 21. In this case, the plastic material of the first housing component can effectively protect the electrical components in the interior of the device 20 from external influences, such as, for example, moisture or dust.

[0036] In the embodiment shown here, contact is made with two electronic components. However, it is also possible to contact only one electronic component or, if necessary, also a plurality of electronic components or other components that generate waste heat in the interior.

[0037] exist Figure 4 2 shows a second embodiment of the device 20 ′, wherein a slightly modified first housing component 51 and a modified cooling body 50 are used compared to the first embodiment. In the embodiment shown here, the remaining components are the same as in the embodiment shown here. Figure 2 middle, Figure 4 The heat sink 50 is identical to that described in the previous section and therefore also has the same reference numerals. Figure 2The heat sink 35 in the embodiment is similarly shaped, but has openings 52, for example holes introduced into the surface of the heat sink 50 in the form of slits or circles, on the side facing away from the printed circuit board 28. The heat sink 50 is immersed in the plastic material of the first housing component 51 in the contact areas 54, 55, 56 extending parallel to the outer side 53 of the first housing component 51. This is, for example, so that the heat sink 50 is injection-coated with the plastic material of the first housing component 51 during the injection molding process. In other embodiments, it is also possible to heat the plastic material of the first housing component 51 strongly and press the heat sink 50 into the molten material. In this case, the openings 52 facilitate the immersion or the injection encapsulation.

[0038] The surface of the cooling body 50 is preferably on both sides of the surface, but if necessary, according to Figure 1 The structuring is also provided only on one side, so that an optimal connection to the plastic material of the first housing component 51 is achieved. The heat transfer to the plastic material can be further improved by the cooling body 50 being connected to the plastic material of the first housing component 51. In addition, the connection between the plastic material and the cooling body 50 is also mechanically fixed.

[0039] exist Figure 2 and Figure 4 In the embodiment of , there is no contact between the exterior space 24 and the heat sink 35 , 50 , so that the device 20 is sealed relative to the exterior space, and no contact is produced relative to the metallic heat sink, so that the metallic heat sink is also electrically insulated to the outside.

[0040] exist Figure 5 , an exemplary embodiment in the form of a device 20 ″ is shown, in which an even better cooling performance is achieved. Here, a heat sink 60 is inserted into an opening 62 of a housing component 61 in such a way that it contacts the exterior 24 . Here, the heat sink has cooling ribs 65 facing the exterior 24 .

[0041] Here, the cooling body 60 contacts the plastic material of the first housing component 61 at the edge 64 of the opening 62. Due to this contact and because the cooling body 60 has no openings, the interior 23 is sealed relative to the exterior 24. In the embodiment shown here, the cooling body 60 does not protrude beyond the surface 63 of the first housing component 61.

Claims

1. A device (20) comprising at least one electronic component (29, 30) and at least one housing component (21) made of a plastic material, wherein: The electronic components (29, 30) are connected to a metallic cooling body (35) for dissipating heat from the electronic components (29, 30), wherein the cooling body (35) has a surface area (44, 45, 46) with a surface structured portion, and wherein the cooling body (35) is connected to the at least one housing component (21) in the area of ​​the surface structured portion, in particular in a non-positive and / or positive manner.

2. The device according to claim 1, characterized in that The locking connection between the heat sink (35) and the housing component (21) is achieved by means of a joining process, in particular by means of direct thermal joining or an injection molding process.

3. The device according to any one of the preceding claims, characterized in that The housing component (21) is constructed as an injection-molded component.

4. The device according to any one of the preceding claims, characterized in that The housing component has an opening toward the exterior (24) of the device (20) in such a way that the surface of the heat sink is accessible to the air flow through the opening.

5. The device according to claim 4, characterized in that The heat sink has cooling ribs (65) in the region of the opening.

6. The device according to any one of claims 4 or 5, characterized in that The housing component (21) and the cooling body (35) are connected to each other in such a way as to seal the interior space (23) of the device relative to the exterior space (24) of the device.

7. The device according to any one of claims 1 to 3, characterized in that The cooling body (35) is completely covered by the housing component (21) relative to an exterior space (24) of the device (20).

8. The device according to any one of the preceding claims, characterized in that The electronic components (29, 30) are arranged on a printed circuit board (28), and the printed circuit board (28) is arranged on a side of the electronic components (29, 30) facing away from the heat sink (35).

9. The device according to any one of claims 7 to 8, characterized in that The electric wires (32) directed toward the printed circuit board (28) or toward the electronic components are arranged in a manner embedded in the housing assembly (21).

10. The device according to any one of the preceding claims, characterized in that The cooling body (35) is shaped in such a way that it has a region extending parallel to the surface of the housing component and the electronic component, and at least one intermediate region connecting the two regions, wherein the intermediate region has an orientation in space that is different from the two other regions and is in particular oriented perpendicularly to the two other regions.

11. The device according to any one of the preceding claims, characterized in that The housing component (21) covers the cooling body (35) in such a way that a heat flow from the electronic component to an exterior space (24) of the device (20) extends through the cooling body (35) and the housing component into the exterior space (24).

12. Method for producing a device, in particular according to any one of the preceding claims, wherein: A housing component (21) is manufactured from a plastic material, in particular by means of an injection molding process, wherein a metallic heat sink (35) is manufactured, wherein a surface area of ​​the heat sink (35) is structured, wherein the heat sink is locked to the plastic material of the housing component (21) at the structured surface area.

13. The method according to claim 12, characterized in that The plastic material of the housing component (21) is melted in such a way that it embeds into the structure of the structured surface area of ​​the heat sink (35) in order to produce the connection between the heat sink (35) and the housing component (21).

14. The method according to claim 12, characterized in that The housing component is produced in an injection molding process, and during the injection molding process the heat sink is partially introduced into an injection molding tool in such a way that a part of the heat sink is injection-coated with the plastic material of the housing component.

15. The method according to any one of claims 12 to 14, characterized in that The electronic component is connected to the heat sink, in particular by means of an arrangement of heat-conducting material.

Images