Electrical device and method for manufacturing an electrical device

Abstract

Electrical device, wherein a circuit board (12) of the device is equipped with heat-generating components (3) and is connected to a cooling plate (1), wherein a plastic body, in particular a partial body (4) of a two-part plastic body (4, 10), is arranged between the circuit board (12) and the cooling plate (1), wherein the plastic body, in particular a partial body (4) of the plastic body (4, 10), has a recess which, together with at least the cooling plate (1) and one or more components (3), forms a channel (14) or a channel system, the surface of which is formed at least partially by a respective surface area of ​​a respective heat-generating component (3) and at least partially by a surface area of ​​the cooling plate (1), wherein a cooling medium, in particular air, is arranged in the channel (14) or channel system, characterized in that the electrical device is a converter.wherein the signal electronics and the power electronics of the inverter are arranged on the circuit board (12), wherein the cooling plate (1) is arranged outside the plastic body, wherein a power module (5) of the power electronics projects through a recess in the plastic body, wherein a first side of the circuit board (12) or at least a partial area of ​​this side is covered, in particular completely covered, by the first partial body (4) of the plastic body, in particular by its first partial body (4), and wherein the other side of the circuit board (12) is at least partially covered by the second partial body (10) of the plastic body, wherein the second partial body is annular in shape.

Description

The invention relates to an electrical device and a method for manufacturing an electrical device. It is known that inverters, as electrical devices, contain signal electronics and power electronics. The power electronics supply power to a load, such as an electric motor. The heat, particularly from the power semiconductor switches of the power electronics, is dissipated to a heat sink and from there to the ambient air or another surrounding cooling medium. To improve heat transfer, it is known to introduce thermal paste into the heat transfer area. From DE 100 36 301 A1, a high-voltage generator with hybrid insulation is known as the closest prior art. From DE 44 42 944 A1 a protective box for mounting and holding on a measuring instrument installation is known. A printed circuit board arrangement with a heat sink is known from US patent 4,459,639 A. The invention is therefore based on the objective of further developing an electrical device, whereby the manufacturing process should be simple. According to the invention, the problem is solved in the device according to the features specified in claim 1 or 2 and in the method according to claim 15. Key features of the invention are that the electrical device, in particular the converter, has a printed circuit board which is equipped with heat-generating components and is connected to a cooling plate, wherein a plastic body, in particular a partial body of a two-part plastic body, is arranged between the printed circuit board and the cooling plate, wherein the plastic body, in particular a partial body of the plastic body, has a recess which, together with at least the cooling plate and one or more components, forms a channel or a channel system, the surface of which is formed at least partially by a respective surface area of ​​a respective heat-generating component and at least partially by a surface area of ​​the cooling plate, wherein a cooling medium, in particular air, is arranged in the channel or channel system. The advantage here is that heat from the heat-generating components flows into the cooling medium and is then transported to the cooling plate, which in turn spreads the heat, thus enabling the heat transfer to the housing at a lower temperature. This even eliminates the need for thermal paste on the contact surface between the cooling plate and the housing. The housing surrounds the circuit board and cooling plate on both sides, thus enclosing both, and therefore further spreads the heat across the entire surface of the housing. In an advantageous embodiment, the cooling medium is driven by a fan, in particular an electrically driven fan, and flows through the channel or channel system, especially where the fan is arranged within the channel or channel system. The advantage here is that, in contrast to convective cooling, a significantly more efficient cooling effect can be achieved. Therefore, relatively small surface areas of the heat-generating components in the contact area with the channel system and relatively small surface areas of the cooling plate are sufficient to accomplish the heat transfer. According to the invention, the channel is shaped in an annular form. An advantage of this is that effective cooling is enabled, since a coolant circuit can be activated, thus allowing for effective flow. In an advantageous embodiment, the device housing comprises a housing part, in particular a cup-shaped housing part, and a cover part, wherein the cover part is placed on the housing part, and a cable gland is arranged between the cover part and the housing part. The advantage here is that no additional manufacturing step is required to create the seal; instead, when the cover part is placed on the cable gland and the housing part, the cable gland is elastically deformed, thus simultaneously creating the seal to the cable when the cover part is connected. This allows for particularly fast and simple manufacturing of the device. In an advantageous embodiment, the cable gland is received in a recess in the cover part or the housing part, which is designed as a receiving recess and tapers in the direction away from the other part, in particular the housing part or the cover part, and is especially U-shaped. It is advantageous that when the cover part is connected to the housing part, the cable gland is pressed towards the bottom of the recess, in particular towards the bottom of the U, and is thus elastically deformed. Since a force distribution is essentially uniform along the U, a high degree of sealing is achieved. The term U-shape also includes U-like shapes or semicircular shapes. In an advantageous embodiment, the cable gland is formed in one piece and / or is made of an elastically deformable material, such as rubber or plastic, in particular where the cable gland can be deformed by placing and connecting the cover part to the housing part, and is particularly elastically deformable. It is advantageous that the cable gland can be manufactured cost-effectively as a cable seal, especially as an injection-molded part and / or a rubber part. Furthermore, a tight seal can be achieved with the contacting cover part and with the housing part contacting the cable gland because the soft material of the cable gland conforms to irregularities in the contact surface and also hugs around edges. In an advantageous embodiment, the cable gland has a channel for the passage of at least one cable, wherein the channel opens into the interior of the device at its first end and into the external environment of the device at its other end. An advantage of this is that a cable can be routed through the channel, thus ensuring a tight seal against the channel wall even if the cable gland is deformed. In an advantageous embodiment, the channel has at least one membrane that is pierced upon initial cable insertion, with the remaining membrane parts resting against the cable, and in particular, the membrane sealing the cable entry until a cable is inserted. It is advantageous that the membrane remnants left behind after piercing adhere closely to the cable and the inner wall of the channel, thus contributing to a tight seal. In an advantageous embodiment, the cable gland has a circumferential groove, in particular into which the wall of the housing part engages in a first section of the groove and into which the wall of the cover part engages in another section of the groove. The advantage of this is that a particularly good seal is achieved and that the cable gland can be held in place in the housing part or cover part even before the cover part or housing part is joined. In an advantageous embodiment, the cover part and the housing part are screwed together, in particular wherein the connecting screws are screwed into threaded bores which are located in respective mounting bosses formed on the housing part, and in particular wherein the screw heads press the cover part against the housing part. An advantage of this is that a simple and cost-effective connection can be produced. In an advantageous embodiment, when the cover part is placed and connected, particularly by screwing, to the housing part, the cable gland is deformed in such a way that the wall of the cable gland channel fits so tightly against the cable that the cable is connected to the cable gland tightly and / or with a high degree of protection, in particular splash-proof and tight against water at an overpressure of 0.1 bar. An advantage of this is that a tight connection with a high degree of protection can be achieved simply and cost-effectively. This is because the cable gland can be manufactured in one piece, particularly as an injection-molded plastic part or a rubber part. Thus, an elastically deformable material can be used.The cable entry point towards the cover part can be designed with a slightly curved contour that corresponds to a straight contour of the cover part. This ensures that the force introduced into the cable entry from the housing part when the cover part is placed acts essentially in the center of the curved contour and is distributed towards the contact surface of the cable entry with the cover part, and in particular, is distributed essentially uniformly. This uniformity of distribution is achieved particularly well with an approximately U-shaped contour of the receptacle arranged in the housing part, which comes into contact with the contact surface of the cable entry. In an advantageous embodiment, the cable gland has a convex contour in the surface area intended as the contact area for the cover part or the housing part before installation in the device, and the cover part or the housing part has a flat contour in this surface area, and / or the housing part or the cover part has a U-shaped recess to receive the cable gland, so that after completion of the device, the force introduced at the convex contour due to the elastic deformation of the cable gland in the completed device with the cover part placed on the housing part is distributed essentially uniformly along the U-shaped contour and transferred to the other part, in particular the housing part or the cover part. An advantage of this is that the seal experiences a uniform force distribution and thus a high degree of sealing reliability is achieved. In an alternative advantageous embodiment, the U-shaped contour and the straight contour are interchangeable, and the cable entry is rotated accordingly. In this case, the cover part, rather than the housing part, has the U-shaped recess. Similarly, the straight contour is located on the housing part instead of the cover part. In an advantageous embodiment, the device comprises a printed circuit board (PCB) equipped with heat-generating components, the PCB being arranged in a housing of the device, the housing comprising a housing part, in particular a cup-shaped housing part, wherein the PCB is connected to a cooling plate to form a slide-in unit, in particular a cassette, preferably by screws, the slide-in unit being inserted into the interior of the housing part and detachably connected to the housing part, preferably by screws. An advantage of this is that the electrical device is environmentally friendly to maintain and repair. In the event of an electronic failure, only the cassette needs to be pulled out of the device installed in a system or machine and the new cassette inserted. In this way, replacing the electronics is quick and easy.Since the connection between the cassette and the housing is detachable, assembly and disassembly are simple. Heat dissipation from the cooling plate to the housing is even possible without thermal paste, as the contact area between the cooling plate and the housing can be made sufficiently large. In an advantageous embodiment, the electrical device comprises an inverter and signal electronics generating pulse-width modulated control signals, as well as line electronics, which include power semiconductor switches in a power module to which the pulse-width modulated control signals are supplied. These components are arranged on the same circuit board. The advantage here is that the inverter electronics can be accommodated on a single circuit board, even though the power electronics handle high currents and the signal electronics handle low currents. In an advantageous embodiment, a ground connection between the circuit board and the cooling plate is established by means of a screw that connects the circuit board and the cooling plate. The advantage here is that a ground connection can be created simultaneously with the mechanical connection. In an advantageous embodiment, a further screw connects the circuit board and the cooling plate, with a power module positioned between them, thus defining a distance between the circuit board and the cooling plate. It is advantageous that the circuit board is attached to the cooling plate with two screws, with the power module positioned between the second screw to provide spacing. The cooling plate can be designed with a mounting boss at the other screw such that this boss rests directly against the side of the circuit board facing away from the screw head of the other screw. In an advantageous embodiment, the cooling plate connected to the circuit board is pressed against the inner wall of the housing part by a wedge, in particular pressed in such a way that heat from at least one heat-generating component, especially a power module comprising a power semiconductor switch, can be dissipated to the housing part at a contact surface. An advantage here is that a simple yet efficient connection technology is used between the cooling plate and the housing part. This ensures good heat transfer and even eliminates the need for thermal paste. Manufacturing tolerances are easily compensated for. Clamping is possible without misalignment, as this would not be achievable due to manufacturing tolerances. The wedge and associated screw can be pre-assembled in the cassette formed by the circuit board and cooling plate before the cassette is connected to the cup-shaped housing part. Furthermore, environmental protection is improved because only the cassette needs to be replaced if the electronics are defective. The pot-shaped housing is reusable and can remain installed in the system while the cassette is being replaced. This also reduces repair costs. In an advantageous embodiment, the wedge is supported on a section of the housing part, in particular on a section of the housing part projecting into the interior area of ​​the device surrounded by the housing part. It is advantageous that the cooling plate can be clamped by the wedge by supporting it on the section and pressing the cooling plate against the housing part. In an advantageous embodiment, the section is a mounting boss. A benefit of this design is that the housing part, together with the section, can be easily manufactured as a single piece. Alternatively, a two-piece design is also possible if the pieces are joined appropriately. In an advantageous embodiment, a screw can be screwed into a recess, in particular a threaded bore, of the section such that, when screwed in, the screw, and in particular its screw head, presses against the wedge and thus, via an inclined surface, in particular a surface having an angle between 0° and 90° to the screw axis, a pressure force is transferred from the wedge to the cooling plate. An advantage of this is that manufacturing tolerances can be easily compensated for and the cooling plate can be pressed against the inner wall of the housing part with a high force. In an advantageous embodiment, the section has a guide for the wedge, in particular wherein the guide has at least one guide groove which is aligned parallel to the screw axis. It is advantageous that the wedge can be guided in the screw axis direction and the clamping force can be easily dissipated via an inclined surface. In an advantageous embodiment, the wedge has a recess, in particular a round hole or bore, through which the screw projects. It is advantageous that the diameter of the recess is smaller than the outer diameter of the screw head but larger than the diameter of the screw thread. Thus, the screw head can be used as a clamping element. In an advantageous embodiment, two such wedges are provided on the circuit board, thus achieving a stable connection between the cassette and the housing part. In an advantageous embodiment, a plastic body at least partially encloses the printed circuit board (PCB) and is connected to the populated PCB, particularly by a material bond and / or a form-fit connection. The advantage here is that the PCB, along with the populated components, is protected from mechanical impacts such as shocks, vibrations, or the like. In particular, protruding components can be better stabilized against vibrations by means of the plastic body. This ensures safe transport and storage, as the PCB is not installed in the device housing. With a thermally conductive plastic body, improved heat dissipation from the heat-generating components can also be achieved. Alternatively, a plastic body is arranged on both sides of the printed circuit board and connected to the populated circuit board, particularly by a material bond and / or a form-fit connection. The advantage here is that the plastic body surrounds the circuit board, thus ensuring good mechanical protection. In an advantageous embodiment, the plastic body is composed of at least two form-fittingly connected sub-bodies, in particular wherein the form-fitting connection is a snap-fit. It is advantageous that the sub-bodies can be prefabricated and thus arranged around the printed circuit board and connected to each other. Therefore, the printed circuit board does not need to be stressed when arranging the sub-bodies around it. In a preferred embodiment, the plastic is made of polystyrene or foam, in particular polyurethane foam. The advantage here is that a cost-effective material can be used, which can be enhanced with chemical additives to improve its thermal conductivity. The term polystyrene also includes any other foamed plastic, especially one that is thermally conductive and electrically insulating and preferably contains a flame retardant additive. In an advantageous embodiment, the plastic exhibits better thermal conductivity, in particular specific thermal conductivity, than air. In particular, the plastic body is made of an electrically insulating material. An advantage of this design is that the thermal conductivity can be improved through the addition of appropriate additives. Furthermore, this eliminates the need for air as a heat transfer medium and allows the plastic body to be placed directly between the circuit board and the cooling plate. According to the invention, the electrical device is a converter, in particular wherein the signal electronics and the power electronics of the converter are arranged on the printed circuit board. An advantage is that only one printed circuit board needs to be populated, thus enabling highly automated manufacturing, since the assembly can be carried out by pick-and-place machines. Furthermore, connecting the electronic circuit, i.e., comprising the printed circuit board with the attached cooling plate, to the housing is particularly simple and easy to perform, since it only requires inserting the electronic circuit into the cup-shaped housing. In an advantageous embodiment, a power module is arranged on the circuit board, which is connected to a cooling plate, in particular a cooling plate containing aluminium. The power module is screwed onto this cooling plate and thermally connected to it for heat dissipation. An advantage of this design is that the cooling plate can be connected to the circuit board via the power module during assembly. This means that the plastic housing protects one side of the circuit board—the side facing away from the cooling plate—while the other side is protected not only by the remaining part of the plastic housing but also by the cooling plate. In an advantageous embodiment, the cooling plate is arranged outside the plastic body, in particular wherein the power module projects through a recess in the plastic body. An advantage of this is that the heat dissipation through the otherwise protective plastic body is not impaired. In an advantageous embodiment, the plastic body has recesses for components mounted on the circuit board, particularly for large components. It is advantageous that heat dissipation to the cooling plate can be achieved in these areas via air or – as in the case of the power module – through a contact surface on the cooling plate. In an advantageous embodiment, the plastic body, particularly the second sub-body, has a further recess that provides an air connection between a heat-generating component mounted on the circuit board and a surface area of ​​the cooling plate, specifically for heat dissipation to the cooling plate via this air connection. It is advantageous that the recess in the plastic body, associated with the respective heat-generating component or the corresponding surface area of ​​the circuit board, creates an air space that is at least partially bounded by a surface area of ​​the cooling plate and by the respective heat-generating component or its corresponding surface area of ​​the circuit board. Thus, when driven by the fan, an airflow is generated, enabling heat dissipation to the cooling plate. According to the invention, a first side of the circuit board or at least a partial area of ​​this side is covered, in particular without gaps, by the plastic body, in particular by its first partial body, and The other side of the circuit board is at least partially covered by the plastic body, specifically by its second sub-body, which is ring-shaped. This offers the advantage that the covered components mounted on the circuit board are protected from environmental influences, such as mechanical impact. The plastic body thus performs a housing-forming function—to the extent of its coverage. It is also more elastic than an aluminum housing. Only after installation in the cup-shaped housing part and closing it with the lid is a complete housing created. In this installed state, the plastic body also assumes a heat-dissipating function, or rather, creates air spaces for the targeted cooling of heat-generating components, provided its thermal conductivity is lower than that of air. In an advantageous embodiment, the housing of the device has a pot-shaped housing part which is closed by a lid part. In particular, a contact surface for heat transfer from the cooling plate to the housing is arranged on the inner wall of the cup-shaped housing section. An advantage of this design is that the heat transferred from the cooling plate to the housing can be spread across the entire cup-shaped housing section. This distributes the heat over a large surface area. However, it is essential to ensure optimal thermal contact between the contact surface and the cooling plate. Since the cooling plate itself can be large and flat, comparable in size to the entire circuit board, sufficient heat transfer is easily achieved, even without thermal paste in the contact area. The integration of the cassette, consisting of the cooling plate, plastic body, and circuit board, into the cup-shaped housing also allows for the simple production of various versions. This is because the same cassette can be installed in different housing sections.This allows application-specific or market-specific requirements to be addressed through appropriately modified housing components. The cover components can be varied accordingly. A high degree of variance can be achieved with a small number of components. In a preferred embodiment, cable glands are arranged between the lid and the housing, particularly for supply lines, lines feeding a consumer, and data bus lines. It is advantageous that the pot-shaped housing can be designed with a base that is as low as possible, i.e., with high side walls. Key features of the method for manufacturing an electrical device are that the device comprises a printed circuit board (PCB) equipped with at least one power module and other components, in particular wherein the components and the power module are thus mounted on the PCB, wherein (i) in a process step the PCB is at least partially enclosed with a plastic body, in particular by inserting the PCB between at least two sub-bodies of the plastic body, which is formed in at least two parts, wherein a fan is arranged in a recess of one of the two sub-bodies and the sub-bodies are connected to each other after insertion, in particular by positive locking and / or by means of a snap-fit ​​connection, (ii) in a subsequent process step a cooling plate is connected to the power module, in particular by screw connection,(iii) in a further subsequent process step, the printed circuit board together with the cooling plate and plastic body is inserted into a pot-shaped housing part and the cooling plate is pressed against a contact surface of the inner wall of the housing part, in particular thermally connected by a wedge which, when screwed together, increasingly presses the cooling plate against the inner wall of the pot-shaped housing part. A key advantage is that the circuit board is encased in a protective plastic housing, thus safeguarding it during transport and storage. Once the cooling plate is attached, this protection is further enhanced, and the electronic circuit, particularly the cassette, can be transported as a single unit. For final assembly, the cassette simply needs to be inserted into the pot-shaped housing and its cooling plate brought into contact with the housing for heat dissipation. The housing is made of metal, such as aluminum, to ensure efficient heat dissipation and high mechanical stability. The fan is preferably powered from the circuit board. Therefore, the power supply lines for the fan run from the circuit board to the fan. The circuit board itself is powered via supply lines routed through the cable gland into the interior of the device. Further advantages arise from the dependent claims. The invention is not limited to the combination of features of the claims. For those skilled in the art, further meaningful combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent, in particular from the problem statement and / or the problem arising from a comparison with the prior art. The invention will now be explained in more detail with reference to schematic illustrations: Fig. 1 shows a purely schematic cross-section through a cassette of an inverter according to the invention, wherein the cassette comprises a plastic body formed from a first and a second foam part (4, 10), which surrounds a circuit board that is thermally connected to a cooling plate 1 arranged outside the plastic body. Fig. 2 shows a purely schematic cross-section in a direction perpendicular to the sectional direction of Fig. 1. Fig. 3 shows a specific oblique view of the sectioned inverter with the cover part 8 removed. Fig. 4 shows an oblique view of the cassette formed from the circuit board 12 and the cooling plate 1, which is arranged inside the inverter. Fig. 5 shows an enlarged detail of Fig. 4.Figure 6 shows an oblique view of the inverter with the cover part 8 removed. Figure 7 shows a cross-section through the inverter with the cover part 8 removed. Figure 8 shows a cross-section through the cassette. Figure 9 shows another cross-section through the cassette. Figure 10 shows a side view of the cassette. In Figures 3, 4, 5, 6, 7, 8, 9 to 10, the plastic body has been removed. Figure 11 shows the cover part 8 detached from the cup-shaped housing part 9, with the cable gland 60 also shown detached, i.e., exploded. Figure 12 shows a top view of the inverter, with the view directed towards the cover part 8, and the display element, in particular the display, omitted. Figure 13 shows a cross-section through the Inverter with cover shown. In the Fig.Figure 14 shows an oblique view of the cable gland 60. Figure 15 shows a top view of the cable gland 60. The inverter housing comprises a pot-shaped, one-piece housing part 9, preferably made of aluminum, which is closed by means of a cover part 8. Cable glands are provided in the intermediate area between the cover part 8 and the pot-shaped housing part 9, allowing supply cables to be inserted into the interior and connection cables to the electric motor powered by the inverter (i.e., the load) to be routed out. Data bus cables are also routed into the interior through a cable gland located there. The electric motor is preferably a three-phase motor. The supply cables preferably carry single-phase or three-phase AC mains voltage. Inside the inverter, a cassette is inserted which includes the inverter's circuit board 12 and a cooling plate 1. The entire electronic circuitry of the inverter, including signal electronics and power electronics, is arranged on the circuit board. The power electronics include at least: a rectifier, which rectifies the AC voltage supplied via the supply cables; a DC link capacitor for smoothing the rectified voltage; and a power module, which has power semiconductor switches arranged in half-bridges that supply the lines powering the motor. The signal electronics generate pulse-width modulated control signals for the power semiconductor switches and are connected to the data bus. The circuit board 12 is therefore equipped with at least one large component 3, such as the intermediate circuit capacitor and power module 5. Furthermore, the circuit board 12 is also equipped with small components 11, such as SMD components or microcontrollers. Some of these small components 11 also generate heat, so their heat must be dissipated to the environment. The power module 5 is screwed to a cooling plate 1 by means of a connecting screw 90, having a screw head, so that the heat from the power module 5 can be dissipated at the contact surface 91 with the cooling plate 1. The power module 5 has a ceramic-coated or copper-plated contact surface 91. The cooling plate 1 is preferably made of aluminum. This ensures a good thermally conductive contact and effective heat dissipation. The cooling plate has a surface area of ​​more than 50%, and in particular more than 80% or 90%, of the printed circuit board area. Even improved heat dissipation can be achieved if the surface area of ​​cooling plate 1 exceeds the surface area of ​​the printed circuit board. Thus, a spread of the heat generated by the power module is achieved. When the cassette is inserted into the cup-shaped housing part 9, the cooling plate is pressed against the inner wall of the cup-shaped housing part, particularly increasingly so when the corresponding connecting screws are tightened, which connect the cassette to the cup-shaped housing part 9. Thus, the heat from the cooling plate 1 is then transferred to the cup-shaped housing part 9 and thereby dissipated. It is important that the pot-shaped housing part encloses the cassette, except for the lid area. Thus, the circuit board sits on both sides within this housing part 9, which maintains approximately the same temperature. The signal electronics and power electronics are therefore at the same temperature level. The circuit board 12 is surrounded on both sides by foam parts (4, 10), i.e., it is wrapped. A cooling plate 1 is arranged on only one side of the circuit board 12, so that only the circuit board 12, but not the cooling plate 1, is wrapped on both sides. In Fig. 1 and Fig. 2, the one-piece molded foam part 4 is marked with the reference numeral 4 at several positions. Without the channel 14, the foam part 4 would one-piece fill the space between the circuit board 12 including components (3, 11) and the cooling plate 1. The first foam part 10 is arranged on the first side of the circuit board. The second foam part 4 is arranged on the other side, i.e., between cooling plate 1 and circuit board 12. The two foam parts 4 and 10 can be connected and are joined by means of two locking mechanisms (2, 6). Thus, they essentially clamp around the circuit board 12. The second foam section 4 has recesses 14 designed as cooling channels, forming a closed cooling circuit for a cooling medium such as air or gas. The heat-generating components, such as one or more small or large components 3 and, if applicable, the power module 5 or surface parts of the power module 5, project into a respective cooling channel 14. The cooling channels are designed to allow cooling of the surface parts of these components that define the cooling channel. An electrically powered, motor-driven fan is arranged within the cooling channel structure formed by the cooling channels, ensuring that the cooling medium flows through the cooling channel circuit. This enables more effective heat dissipation than with convective flow. The foam part 4 is therefore approximately similar to a cuboid in which an annular cooling channel 14 is cut out, the ring (cooling channel 14) being open in one part towards the circuit board 12 and in another part of the ring towards the cooling plate 1. The foam components also improve electrical insulation. The cooling channel structure also includes cooling channels that are bounded by surface areas of the cooling plate 1. Thus, heat can be transferred from the cooling medium to the cooling plate 1 in these areas. The locking mechanism (2, 6) of the foam parts 4 and 10 is achieved by their shaping, and therefore can be implemented without additional parts. A locking lug is formed on one of the foam parts 4 or 10, and a corresponding recess with a locking projection is formed on the other. A positive-locking connection is created by engaging behind the projection, i.e., by locking the parts together. The foam components protect the circuit board 12 against mechanical impacts such as shocks and / or vibrations. Therefore, the circuit board 12 can be safely stored and transported in this packaging formed by the foam components. However, by inserting and positioning the circuit board, along with the transport packaging formed from the foam components (4, 10), into the housing of the electrical device, simple assembly is enabled, the circuit board 12 remains mechanically secure, and the amount of waste is reduced. This is because the foam components (4, 10) are not disposed of but rather incorporated into the device. Thus, environmental protection is improved. Due to the active ventilation, even a heat-insulating or poorly conductive material can be used for the foam components. This is because the main heat flows from the heat-generating components via the cooling medium to the cooling plate and from there via the housing component to the environment. Therefore, a material can be used for the plastic body whose thermal conductivity is lower than that of air. In the present invention, "air" means the ambient air of the inverter and / or air with a temperature of 20 °C at 1 bar pressure and a humidity of 30%. Polyurethane or polystyrene foam can be used as the foam material. However, if the thermal conductivity of the foam material exceeds that of air, heat dissipation is further improved. Furthermore, depending on the application or customer requirements, differently shaped, pot-shaped housing parts 9 can be connected to the cassette. Similarly, differently shaped cover parts 8 can be connected. In this way, inverters with different external appearances and correspondingly different functionalities can be manufactured without having to redesign the circuit board 12 each time. The only important factor is that the interface to the cassette is compatible; in particular, the interface for connecting the cooling plate 1 to the inner wall of the pot-shaped housing part 9 must be compatible. The locking mechanism 2 and 6 is preferably designed to be releasable. Preferably, thermal paste is omitted in the contact area between the cooling plate and the housing part. The surface area is sufficiently large to allow for effective heat dissipation. In the alternative embodiments shown in Figures 3 to 15, compared to the embodiments shown in Figures 1 and 2, the foam components (4, 10) are not visible, i.e., hidden. Nevertheless, they can be foreseen around the circuit board. Therefore, disposal is not necessary. Furthermore, the foam components improve the mechanical stability and protect the circuit board. As shown in Fig. 3, a recess 30 for a cable gland 60 is arranged at the upper edge, i.e., at the edge facing the cover part 8. The recess forming the recess 30 is U-shaped. It tapers downwards, i.e., towards the bottom of the cup-shaped housing part 9. The clear opening thus decreases uniformly in this direction. This allows for the use of a flexible cable gland 60, which is pressed downwards and elastically deformed when the cover part 8 is placed on top. A cable passing through the cable gland 60 is thereby very effectively sealed. A connection means 31 for electrical lines is also arranged on the circuit board 12, to which the supply lines led through a cable gland 60 and the lines supplying the motor can be electrically connected and joined. The input and display means arranged in the cover part 8 are electrically connected by means of a cable leading from the cover part 8 to the circuit board 12, wherein a connector part is arranged at the end of the cable, which can be plugged into a mating connector part arranged on the circuit board 12. Alternatively, the connector part can also be arranged on the cover part 8 and plugged into the mating connector part. Figures 3 and 7 also show a dome 32 formed on the bottom of the cup-shaped housing part 9, into which the screw 33 can be screwed. When the screw 33 is screwed in, a wedge 34 is pressed downwards by the screw head of the screw 33. The wedge 34 is guided laterally in the lateral guide lugs 51, each of which has a guide groove 50 extending in the direction of the screw axis for guiding the wedge 34. The wedge 34 has a hole through which the screw 33 protrudes and on whose edge area the screw head is supported. The guide lugs 51 are formed on the cooling plate 1. A second sliding surface 71 is also formed on the cooling plate 1, which runs obliquely to the screw direction and obliquely to the normal direction of the cooling plate 1, i.e., with a decreasing distance to the screw in the screw direction. A correspondingly oblique first sliding surface 70 is arranged on the wedge 34, so that when the screw 33 is screwed into the dome 32, the cooling plate 1 is pushed away from the dome 32. In this way, the contact surface of the cooling plate 1 is pressed against a corresponding contact surface on the inner wall of the cup-shaped housing part 9, which is located on the side of the cooling plate 1 facing away from the screw. As shown in Fig. 4, the power module 5 has a contact surface 40 for heat dissipation to the cooling plate 1. The contact surface is highly thermally conductive and therefore preferably designed as a copper or ceramic contact surface. As shown in Fig. 8, the circuit board is connected to the cooling plate 1 by a connecting screw 80, the connecting screw 80 passing centrally through the power module 5 and pressing the power module against the cooling plate with its contact surface 40. The screw head of the connecting screw presses, via a plate-shaped intermediate part, against the side of the circuit board 12 facing away from the cooling plate 1, thus holding the circuit board 12 and the cooling plate together. The distance between the circuit board 12 and the cooling plate is determined by the power module, which therefore also acts as a spacer. As shown in Fig. 9, another connecting screw 90 is also arranged on the circuit board, the screw head of which presses directly against the side of the circuit board facing away from the cooling plate 1. The connecting screw 90 is screwed into a mounting boss 91 formed on the cooling plate. In this way, the circuit board 12 is screwed onto the cooling plate 1. As shown in Fig. 11, the cover part 8 is placed on the cable glands 60 and presses on the curved contour 150 of the cable gland 60, which deforms elastically. The cable gland 60 is made of an elastically deformable plastic and is arranged in the receptacle 30 of the housing part 9. When the cover part 8 is screwed on, the cable gland 60 is pressed into the downwardly tapered receptacle 30 and thus elastically deformed. The cable gland 60 has a channel which is closed with a membrane 130. The channel leads from the outside to the inside of the inverter. The cable gland 60 is preferably formed in one piece and made of plastic or rubber. The cable gland 60 also has a circumferential recess around its outer edge, which allows it to be attached to the wall of the housing part 9 in the area of ​​the recess 30. Likewise, the wall of the housing part of the cover part 8 can be attached to the recess. Thus, and through the deformation of the cable gland 60 caused when the cover part 8 is attached, a very effective seal is achieved. When a cable is inserted into the channel of the cable gland 60, the membrane 130 is pierced, so that the cable is tightly arranged in the channel or at least only small gaps occur between the cable and the cable gland 60, in particular the wall of the channel. The first cable entry 60 can be used for a supply cable that provides the inverter with mains voltage. The second cable entry 60 can be used for a cable that carries the currents supplied by the inverter to the motor. An additional seal is arranged between the lid part and the pot-shaped housing part, running along the edge in the connection area of ​​the two parts. The deformation of the cable gland 60 caused by the placement of the cover part 8 effectively squeezes the cable within the channel of the cable gland 60, thus tightly enclosing it within the material of the cable gland 60. In this way, the cable gland 60 acts as a seal for the cable. The channel is narrow in the cable entry area, with a diameter only slightly larger than the cable, and then widens towards the interior of the inverter. At the opening opposite the diaphragm 130, it narrows slightly to achieve greater stability and service life for the cable gland 60. As shown in Fig. 12 and Fig. 13, two opposing cable feedthroughs 60 are arranged on the converter. As shown in Fig. 15, when the attached cover part 8 is placed into the recess of the cable gland, it acts on the slightly curved edge with the slightly curved contour 150 shown in Fig. 15. Since the edge of the cover part 8 that is in contact with the cable gland is straight, the maximum force is present in the middle of the curved contour 150 and the force decreases towards the rounded corner area. At the other, approximately U-shaped edge, the cable gland 60 rests on the receptacle 30, so that the force acting on the contour 150 is distributed uniformly on the U and thus causes uniform deformation and therefore also sealing. In another embodiment according to the invention, the guide lugs 51 are designed as a separate part and are connected accordingly to the cooling plate 1. In another embodiment according to the invention, the mounting dome 91 is also designed as a separate part and is connected accordingly to the cooling plate 1. In another embodiment according to the invention, a hybrid cable can also be used as the cable, which has not only lines for high currents, but also signal lines, i.e. lines for low currents. In a further embodiment according to the invention, the channel in the cable passage 60 has a further membrane at the opening area opposite the membrane 130, which must be pierced by the cable in order to achieve a further improved seal. Reference symbol list 1 Cooling plate 2 Locking mechanism 3 Large component, in particular capacitor 4 Second foam part 5 Power module, comprising power semiconductor switch 6 Locking mechanism 8 Cover part 9 Cup-shaped housing part 10 First foam part 11 SMD components or small electronic components 12 Circuit board 13 Fan 14 Cooling channel 30 Receptacle for cable entry 31 Connector part 32 Dome, formed integrally on the bottom of the cup-shaped housing part 9 33 Screw 34 Wedge 40 Contact surface for heat dissipation, in particular copper or ceramic contact surface 50 Guide groove for guiding the wedge 34 51 Lateral guide lug 60 Cable entry in the receptacle 30 70 First sliding surface 71 Second sliding surface 80 Connecting screw 90 Connecting screw, in particular with screw head of a connecting screw for screwing the power module to the cooling plate 1 91 Mounting dome for PE screw, i.e. grounding 130 Membrane 131 Direction of force 150 curved contour

Claims

Electrical device, wherein a circuit board (12) of the device is equipped with heat-generating components (3) and is connected to a cooling plate (1), wherein a plastic body, in particular a partial body (4) of a two-part plastic body (4, 10), is arranged between the circuit board (12) and the cooling plate (1), wherein the plastic body, in particular a partial body (4) of the plastic body (4, 10), has a recess which, together with at least the cooling plate (1) and one or more components (3), forms a channel (14) or a channel system, the surface of which is formed at least partially by a respective surface area of ​​a respective heat-generating component (3) and at least partially by a surface area of ​​the cooling plate (1), wherein a cooling medium, in particular air, is arranged in the channel (14) or channel system, characterized in that the electrical device is a converter.wherein the signal electronics and the power electronics of the inverter are arranged on the circuit board (12), wherein the cooling plate (1) is arranged outside the plastic body, wherein a power module (5) of the power electronics projects through a recess in the plastic body, wherein a first side of the circuit board (12) or at least a partial area of ​​this side is covered, in particular completely covered, by the first partial body (4) of the plastic body, in particular by its first partial body (4), and wherein the other side of the circuit board (12) is at least partially covered by the second partial body (10) of the plastic body, wherein the second partial body is annular in shape. Electrical device, wherein a circuit board (12) of the device is equipped with heat-generating components (3) and is connected to a cooling plate (1), wherein the circuit board (12) is arranged in a transport packaging formed from a one-piece or multi-piece plastic body (4, 10), such that at least a partial body (4) of the plastic body is arranged between the circuit board (12) and the cooling plate (1), characterized in that the plastic body, in particular a partial body (4) of the plastic body (4, 10), has a recess which, together with at least the cooling plate (1) and one or more components (3), forms a channel (14) or a channel system, the surface of which is formed at least partially by a respective surface area of ​​a respective heat-generating component (3) and at least partially by a surface area of ​​the cooling plate (1), wherein a cooling medium, in particular air, is arranged in the channel (14) or channel system.the electrical device is an inverter, wherein the signal electronics and the power electronics of the inverter are arranged on the circuit board (12), wherein the cooling plate (1) is arranged outside the plastic body, wherein a power module (5) of the power electronics projects through a recess in the plastic body, wherein a first side of the circuit board (12) or at least a partial area of ​​this side is covered, in particular completely covered, by the first part (4) of the plastic body, in particular by its first part (4), and wherein the other side of the circuit board (12) is at least partially covered by the second part (10) of the plastic body, wherein the second part is annular in shape. Device according to claim 1 or 2, characterized in that the cooling medium is driven by a fan (13), in particular by an electrically driven fan (13), and flows through the channel (14) or the channel system, in particular wherein the fan (13) is arranged in the channel (14) or channel system. Device according to at least one of the preceding claims, characterized in that the channel (14) is shaped in an annular form. Device according to at least one of the preceding claims, characterized in that a plastic body at least partially encloses the circuit board (12) and is connected to the populated circuit board (12), in particular by material bonding and / or form-fitting. Device according to at least one of the preceding claims, characterized in that the plastic body is a partial body (4) of a two-piece plastic body and is arranged on a first side of the circuit board (12), wherein the other partial body (10) is arranged on the other side of the circuit board (12), in particular on the side of the circuit board (12) facing away from the first partial body (4), and / or that the other partial body (10) is connected to the populated circuit board (12), in particular by a material bond and / or a form-fit bond. Device according to at least one of the preceding claims, characterized in that the plastic body is composed of at least two part bodies (4, 10) connected to each other in a form-fitting manner, in particular wherein the form-fitting connection is a locking mechanism (2, 6). Device according to at least one of the preceding claims, characterized in that the plastic of the plastic body is designed as polystyrene or as foam, in particular as polyurethane foam. Device according to at least one of the preceding claims, characterized in that the plastic has a lower thermal conductivity, in particular a specific thermal conductivity, than air, in particular wherein the plastic body is made of electrically insulating material, and / or that the cooling plate (1) is spaced apart from the circuit board (12) by means of one of the heat-generating components, in particular by means of the power module (5), wherein the circuit board (12) and the cooling plate (1) are screwed together, in particular wherein the cooling plate (1) contains aluminum, and / or that the plastic body has recesses for components (3) mounted on the circuit board (12), and / or that the plastic body, in particular the second part (10), has a further recess which provides an air connection between a heat-generating component mounted on the circuit board (12) and a surface area of ​​the cooling plate (1).in particular for the convective dissipation of heat via the air connection to the cooling plate (1), and / or that the plastic body has a further recess for a component (3) mounted on the circuit board (12), and / or that the housing of the device has a cup-shaped housing part (9) which is closed by a cover part (8), in particular wherein a contact surface (40) for heat transfer from the cooling plate (1) to the housing is arranged on the inner wall of the cup-shaped housing part (9), and / or that cable glands are arranged between the cover part (8) and the housing part (9), in particular for supply lines, lines supplying a consumer, and data bus lines. Device according to at least one of the preceding claims, characterized in that the housing of the device comprises a housing part (9), in particular a cup-shaped housing part (9), and a cover part (8), wherein the cover part (8) is placed on the housing part (9), wherein a cable gland (60) is arranged between the cover part (8) and the housing part (9), and / or that the cable gland (60) is received in a recess designed as a receiving in the cover part or the housing part (9), which is tapered in the direction away from the other part, in particular the housing part (9) or the cover part (8), in particular wherein the recess is U-shaped, and / or that the cable gland (60) is formed in one piece, and / or that the cable gland (60) is made of an elastically deformable material, such as rubber or plastic.in particular wherein the cable entry (60) is deformable by placing and connecting the cover part onto the housing part (9), in particular elastically deformable, and / or that the cable entry (60) has a channel for the passage of at least one cable, wherein the channel opens into the interior of the device at its first end region and into the external environment of the device at its other end region, and / or that the channel has at least one membrane (130) which is pierced when the cable is first inserted, wherein the remaining membrane parts rest against the cable, in particular wherein the membrane (130) closes the cable entry (60) as long as no cable has yet been inserted, and / or that the cable entry (60) has a circumferential groove, in particular into which the wall of the housing part (9) engages in a first part of the groove and into which the wall of the cover part engages in another part of the groove. Device according to at least one of the preceding claims, characterized in that the cover part (8) and the housing part (9) are screwed together, in particular wherein the connecting screws (80) are screwed into threaded bores which are located in respective mounting bosses (91) formed on the housing part (9), in particular wherein the screw heads press the cover part (8) against the housing part (9), and / or that when the cover part is placed on and connected, in particular screwed together, to the housing part (9), the cable entry (60) is deformed in such a way that the wall of the channel of the cable entry (60) fits so tightly against the cable that the cable is connected to the cable entry (60) tightly and / or with a high degree of protection, in particular splash-proof and tight against water at an overpressure of 0.1 bar.and / or that the cable entry (60) has a curved contour (150) in the surface area intended as a contact area for the cover part (8) or the housing part (9) before installation in the device, and that the cover part (8) or the housing part (9) has a straight contour in this surface area, and / or that the housing part (9) or the cover part (8) has a U-shaped recess as a receptacle (30) for the cable entry (60), so that after completion of the device, the force introduced at the curved contour (150) as a result of the elastic deformation of the cable entry (60) in the completed device with the cover part (8) placed on the housing part (9) is distributed essentially uniformly along the U-shaped contour and transferred to the other part, in particular the housing part (9) or the cover part (8). Device according to at least one of the preceding claims, characterized in that the device has a printed circuit board (12) equipped with heat-generating components (3), wherein the printed circuit board (12) is arranged in a housing of the device, the printed circuit board (12) is connected to a cooling plate (1) to form a plug-in unit, in particular a cassette, in particular by screws, wherein the plug-in unit is inserted into the interior of the housing part (9) surrounded by the housing part (9) and is detachably connected to the housing part (9), in particular by screws, in particular wherein the electrical device is a converter and signal electronics generating pulse-width modulated control signals as well as line electronics, which have power semiconductor switches in a power module (5) to which the pulse-width modulated control signals are supplied, are arranged on the same printed circuit board (12).and / or that, when the insert unit is detachably connected to the housing part (9), the cooling plate (1) is pressed against the inner wall of the housing part (9) by a wedge (34), in particular pressed in such a way that heat from at least one heat-generating component (3), in particular a power module (5) comprising a power semiconductor switch, can be dissipated to the housing part (9) at a contact surface (40), and / or that the wedge (34) is supported on a section of the housing part (9), in particular on a section of the housing part (9) projecting into the interior area of ​​the device surrounded by the housing part (9), and / or that the section is a mounting boss (91). Device according to claim 12, characterized in that a dome (32) can be screwed into a recess, in particular a threaded bore, of the section such that when screwed in, the dome (32), in particular its screw head, presses against the wedge (34) and thus a pressure force is transmitted from the wedge (34) to the cooling plate (1) via an inclined surface, in particular a surface having an angle between 0° and 90° to the screw axis direction, and / or that the section has a guide for the wedge (34), in particular wherein the guide has at least a guide groove (50) which is aligned parallel to the screw axis direction, and / or that the wedge (34) has a recess, in particular a round hole or a round bore, through which the dome (32) projects. Device according to at least one of the preceding claims, characterized in that a ground connection between circuit board (12) and cooling plate (1) is made by means of a screw which connects the circuit board (12) and the cooling plate (1), in particular wherein a further screw connects the circuit board (12) and the cooling plate (1), wherein a power module (5) is arranged in between and thus determines a distance between circuit board (12) and cooling plate (1). A method for manufacturing an electrical device, in particular according to at least one of the preceding claims, wherein the device comprises a housing part (9) that can be closed with a cover part (8), wherein a cable gland (60) can be arranged between the housing part (9) and the cover part (8), characterized in that in a first method step a cable is passed through a cable gland (60) and in a further method step the cover part (8) is placed on the housing part (9) and screwed on in such a way that the cable gland (60) is elastically deformed in such a way that the cable passing through the channel of the cable gland (60) is tightly and / or with a high degree of protection connected to the cable gland (60), wherein the device comprises a printed circuit board (12) equipped with at least one power module (5) and further components (3),in particular wherein the components (3) and the power module (5) are thus mounted on the printed circuit board (12), in particular wherein the electrical device is a converter and signal electronics generating pulse-width modulated control signals as well as line electronics, which have power semiconductor switches in a power module (5) to which the pulse-width modulated control signals are supplied, are arranged on the same printed circuit board (12), wherein (i) in a process step the printed circuit board (12) is at least partially enclosed with a plastic body, in particular by inserting the printed circuit board (12) between at least two sub-bodies of the plastic body, which is formed in at least two parts, to form a transport packaging, wherein a fan (13) is arranged in a recess of one of the two sub-bodies and the sub-bodies are connected to each other after insertion, in particular by positive locking and / or by means of a latching mechanism (2, 6),(ii) in a subsequent process step, a cooling plate (1) is connected to the power module (5), in particular by screw connection, (iii) in a further subsequent process step, the printed circuit board (12) together with the cooling plate (1) and plastic body is inserted into a cup-shaped housing part (9) and the cooling plate (1) is pressed against a contact surface (40) of the inner wall of the housing part (9), in particular by thermally conductive connection, by a wedge (34) which, during screw connection, increasingly presses the cooling plate (1) against the inner wall of the cup-shaped housing part (9).

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