Electrical device

Abstract

An electrical device comprising - a circuit board loaded at least with heat-generating components, - a heat sink, - a heat-conducting element, -a plate part and - fastening means, wherein the heat sink lies against the circuit board on a first side of the circuit board, wherein the heat-conducting element is located between the heat sink and the circuit board, wherein the components are loaded on the side of the circuit board that is facing away from the heat sink and a compensating part is located between the plate part and the side of the circuit board that is facing away from the heat sink, wherein the compensating element is located between the plate part and the components.

Description

[0001] electrical appliance

[0002] Description:

[0003] The invention relates to an electrical device.

[0004] It is generally known that the waste heat generated by components must be dissipated to the environment.

[0005] From DE 10 2015200 548 A1, an arrangement for cooling at least one electronic component is known as the closest prior art.

[0006] From DE 603 ​​19 523 T2 a device for cooling semiconductor components on printed circuit boards is known.

[0007] A cooling arrangement is known from DE 10 2014 012 349 A1.

[0008] A printed circuit board arrangement is known from US 2009 / 0 116 194 A1.

[0009] The invention is therefore based on the object of developing an electrical device, whereby a long service life is to be achieved, in particular through efficient heat dissipation.

[0010] According to the invention, the object is achieved in the electrical device according to the features specified in claim 1.

[0011] Important features of the invention in the electrical device are that the electrical device comprises a printed circuit board equipped with at least heat-generating components, in particular power semiconductors, in particular a thermally conductive printed circuit board structure, a heat sink, a heat-conducting element, a plate part and

[0012] Has fastening means, wherein on a first side, in particular top side, of the circuit board, the heat sink rests against the circuit board, in particular wherein the heat sink rests against the circuit board with a flat surface area, wherein the heat conducting element is arranged between the heat sink and the circuit board, in particular between the heat sink and the top side of the circuit board, in particular wherein the heat sink is spaced from the circuit board by means of the heat conducting element, wherein the components are populated on the side of the circuit board facing away from the heat sink, in particular underside, and a compensating part is arranged between the plate part and the side of the circuit board facing away from the heat sink, in particular underside, wherein the compensating element is arranged between the plate part and the components, in particular wherein the plate part is spaced from the circuit board by means of the compensating element.

[0013] The advantage here is that the compressive force generated when the fasteners are actuated, especially when screwing, is transferred via the components to the circuit board, and then from the circuit board through the heat-conducting element to the heat sink. When the fasteners are actuated, they move the heat sink and the plate part toward each other. Thus, the plate part spreads the compressive forces, and the compensating element compensates for the component tolerances.

[0014] In particular, the maximum clearances between the surface of the components and the circuit board depend on the tolerances introduced during component assembly. These tolerances result in different clearances between the board and the components.

[0015] The heat dissipated by the components is transported, in particular, by thermal vias arranged in the circuit board from the side of the circuit board facing the components to the other, particularly opposite, side of the circuit board, and then via the heat-conducting element to the heat sink. It is important that the board is not pressed directly against the components, but rather that a compensating element is interposed to compensate for the tolerances, i.e., the different distances between the board and the components.

[0016] The components, especially power semiconductors, especially MOSFETs, diodes, load resistors, or IGBTs, are identical to each other within the scope of manufacturing accuracy and the resulting manufacturing tolerances, but positioning tolerances occur during component assembly. Furthermore, the tolerances also include the different positions of the components, which are caused by the elasticity and bending of the printed circuit board under compressive force.

[0017] The components are primarily power semiconductors and therefore have a sturdy housing. Electrical conductor tracks on the circuit board are firmly bonded, particularly by soldering, to the electrical connection contact surfaces of the components, particularly power semiconductors.

[0018] The compensating element has a higher elasticity than the heat conducting element.

[0019] In particular, the compensating element is softer than the thermally conductive element. This property would actually be a disadvantage, as it could impair thermal contact. However, according to the invention, the force generated by screwing in the screws is spread across the plate part and then transferred to the components mounted on the circuit board via the compensating element. By applying the force in this way, i.e., by applying the force via the plate part and the compensating element, warping or deformation does not impair the contact situation or thermal contact.

[0020] In a particular embodiment, a single screw is provided, which is arranged centrally between three components to be cooled. In a further development, a single screw is also provided, and the components to be cooled are arranged point-symmetrically to the screw, in particular, where more than three screws are provided.

[0021] In another embodiment, to achieve simple assembly, a plurality of components to be cooled is preferably provided. These are more preferably positioned on both sides of screws, in particular to prevent the plate part from tilting when the first of these screws is tightened. The wall thickness of the compensating element is also greater than the wall thickness of the heat-conducting element, which also essentially disappears in the exemplary embodiment of the heat-conducting element as a paste. Preferably, the wall thickness of the compensating element is at least five times greater than the wall thickness of the heat-conducting element.

[0022] The fact that the heat sink is thermally and / or thermally conductively connected to the circuit board by means of the heat conducting element means that the heat transfer resistance of the heat path from the heat sink via the heat conducting element to the circuit board has a lower thermal resistance than any other heat path from the heat sink via the other environment, in particular from the heat sink to the circuit board.

[0023] In an advantageous embodiment, the distances between the plate part and the components are each different, in particular due to manufacturing tolerances, in particular wherein a first of the components protrudes more from the plate part than a second of the components when viewed from the circuit board, wherein the material of the compensating element has a relaxation behavior such that a material portion of the compensating element is plastically deformed such that the elastic residue remaining between the plate part and the respective component is elastically deflected in such a way, in particular by the compressive force of the plate part, that the spring pressure force generated by this respective deflection of the respective elastic residue is essentially the same in each case.

[0024] In an advantageous embodiment, the material of the compensating element is plastically deformed and / or has such a relaxation behavior that each component is loaded with the substantially equal pressure transmitted from the plate part via the compensating element, in particular although the distances are different due to the manufacturing tolerances.

[0025] In an advantageous embodiment, the components are structurally identical and / or designed identically to one another within the manufacturing tolerances, and / or the components each have the same housing type, with the components each having different distances from the plate part, in particular those caused by manufacturing tolerances when populating the circuit board with the components. The advantage here is that the compensating element compensates for the geometric deviations generated during assembly and thus evens out the force transmission from the plate part to all components. Without a compensating element, the compressive force of the plate part would only act on the component with the smallest distance from the plate part.

[0026] According to the invention, however, the elastically and plastically deformed compensating element is interposed, allowing for a more uniform distribution of the compressive forces transmitted to the respective components. Therefore, the compensating element is particularly preferably made of plastic. The compensating element must transmit high forces, be temperature and aging resistant, exhibit low relaxation behavior, meet stringent flame retardancy requirements, and be electrically insulated.

[0027] In an advantageous embodiment, the fastening elements are either screws or threaded bolts with a screwed-on nut. This is advantageous because, when screwed on, the heat sink is pressed toward the circuit board, and the board part is pressed toward the components.

[0028] In an advantageous embodiment, the heat-conducting element comprises or is designed as a thermal paste, a phase transition paste, in particular a phase change paste, a metal foil, in particular aluminum foil or copper foil, coated with a phase transition paste, in particular a phase change paste, a circuit board base material, in particular fiber-reinforced epoxy resin, a circuit board base material, a silicone foil, a coated metal foil, a ceramic material and / or a ceramic foil, in particular a silicone-free foil. The advantage here is that the design with thermal paste enables cost-effective production, whereby a very low heat transfer resistance between the heat sink and the circuit board including thermal vias is achieved, but increased production effort is necessary.In the silicone film version, spacing is reliably guaranteed because the silicone film is interposed; however, silicone is used. In the ceramic film version, spacing is reliably guaranteed and no silicone is used, especially where the absence of silicone is crucial for automotive manufacturing, for example.

[0029] The thermal interface compensates for tolerances between the different flat surfaces and ensures full-surface thermal contact. The thermal conductivity of the thermal interface is pressure-dependent. Higher contact pressure improves the thermal conductivity of the thermal path from the heat-generating component through the thermal interface to the heat sink. If the contact surfaces of the thermal interface are uneven, an air gap can form, which impairs or prevents effective heat dissipation via the thermal interface.

[0030] The contact pressure according to the invention prevents the formation of such an air gap. The contact pressure is maximized as much as possible at the point of localized heat generation, thereby minimizing the thermal contact resistance there.

[0031] Additionally, depending on the intended use, the heat-conducting element may require electrical insulation properties. To maintain the insulation properties, the pressure must not exceed the specified maximum value. The uniform contact pressure according to the invention prevents localized pressure increases, which would lead to the destruction of the insulation properties of the heat-conducting element.

[0032] In an advantageous embodiment, the fastening means protrude through recesses in the heat sink, the circuit board, and the compensating element. This is advantageous because when the fastening means are actuated, particularly when screwed in, the plate part is pressed toward the heat sink, clamping the interposed elements. Lateral migration of the elements, the heat sink, or the plate part is prevented by the fact that the fastening means protrude through the respective element.

[0033] In an advantageous embodiment, when the fastening means are actuated, the distance between the heat sink and the plate part is reduced, in particular so that the heat sink is pressed towards the circuit board and the plate part is also pressed towards the circuit board.

[0034] The advantage here is that the intermediate elements arranged between the plate part and the heat sink are clamped firmly. In an advantageous embodiment, the compensating element is made of polypropylene, Teflon, or hard rubber. The advantage here is that the compensating element can be designed as a cushion and thus transmits the compressive force acting from the plate part and spread across the components. The different distances between the components and the plate part are bridged by the compensating element, thus, in particular, the tolerances are compensated. A cushion made of polypropylene has proven to be particularly advantageous as a compensating element, as this allows suitable thermal resistance, suitable flame protection, suitable pressure resistance, suitable compression set, and a suitable modulus of elasticity to be achieved.

[0035] In an advantageous embodiment, the compensating element is an extruded film, particularly made of polypropylene. In particular, such a film can be produced cost-effectively and the wall thickness can be manufactured with high precision, which is why the film can be used to compensate for existing tolerances without introducing additional tolerances itself.

[0036] In an alternative design, the compensating element has air pockets, particularly in the micro or nano range, or is porous. Although the pressure resistance is then lower and flame retardancy more difficult to achieve, the cushioning design of the compensating element is advantageous for compensating tolerances.

[0037] In an advantageous embodiment, the fastening means are screw-connected to the plate part, in particular screwed into an internal thread of the plate part or into an internal thread of a press-in nut connected to the plate part. This is advantageous in that by screwing the fastening means, which are designed as screw parts such as threaded bolts or screws, the plate part can be pressed towards the heat sink, thus clamping the interposed elements. The clamping force is transmitted from the plate part via the compensating element into the components and not into the circuit board. This is because the plate part or the press-in nuts protruding towards the circuit board is or are spaced apart from the circuit board.

[0038] In an advantageous embodiment, the fastening means have at their

[0039] The end area facing away from the plate part has a screw head or a nut which is

[0040] The advantage of this is that when the fasteners are screwed in, i.e., actuated, the heat sink is pressed toward the circuit board, with the heat-conducting element positioned between them.

[0041] In an advantageous embodiment, the plate part and / or the press-in nuts projecting from the plate part toward the circuit board are spaced from the circuit board by means of the components. This is advantageous because the force flow is directed through the components, thus achieving good thermal contact. Furthermore, any separation of the components from the plate part caused by bending of the circuit board is prevented.

[0042] In an advantageous embodiment, the circuit board is populated on both sides, in particular not in the area of ​​contact with the heat-conducting element or heat sink. This advantageously involves the components being populated on the underside of the circuit board, while other electronic components are populated on the top side.

[0043] In an advantageous embodiment, the press-in nuts protrude through recesses in the compensating element, in particular, and are spaced from the circuit board, particularly by means of the components. This is advantageous because the compensating element is prevented from migrating out laterally, particularly during assembly. Nevertheless, the press-in nuts are spaced from the circuit board.

[0044] In an advantageous embodiment, the heat sink has a continuous recess and / or is hollow. This is advantageous because it enables efficient cooling.

[0045] In an advantageous embodiment, the heat sink has cooling fins that extend into the recess. This has the advantage of efficiently cooling the air flow conveyed by the fan through the recess.

[0046] In an advantageous embodiment, the outer periphery of the heat sink is cuboid-shaped. This is advantageous in that the heat sink rests flat against the circuit board, as one side surface can be aligned parallel to the circuit board.

[0047] In an advantageous embodiment, a fan motor is arranged on the heat sink in such a way that the air flow conveyed by the fan flows through the recess in the heat sink. The advantage here is that efficient cooling can be achieved. In an advantageous embodiment, the circuit board has a heat conduction medium, in particular a thermal via array, wherein the components rest on the heat conduction medium on the one hand and the heat conduction element, which touches the heat sink, on the other hand, i.e. at the end of the heat conduction medium facing away from the components, wherein the heat conduction element is designed as a through-hole and / or as a metal inlay pressed into the circuit board. The advantage here is that the best possible thermal connection between the components and the heat sink is achieved through the circuit board.

[0048] In an advantageous embodiment, the electrically insulating layer in the circuit board is provided as a base material of the circuit board, a material having a specific thermal conductivity of more than 1 W / (m K), in particular more than 1 watt per meter and per Kelvin. An advantage here is that the base material of the circuit board itself can be designed as a highly thermally conductive compound.

[0049] Further advantages emerge from the dependent claims. The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the problem and / or the problem posed by comparison with the prior art.

[0050] The invention will now be explained in more detail using schematic illustrations:

[0051] In Figure 1, a populated circuit board 3, in particular a thermally conductive circuit board structure, of an electrical device according to the invention is shown exploded in an oblique view.

[0052] Figure 2 shows a longitudinal section of the corresponding assembly.

[0053] Figure 3 shows a corresponding top view.

[0054] As shown in the figures, the electrical device has a circuit board 3 that is preferably populated on both sides.

[0055] In Figure 2, the heat-generating components 20, in particular power semiconductors, mounted on the underside of the printed circuit board 3, in particular the thermally conductive printed circuit board structure, are visibly shown.

[0056] A hollow heat sink 1 rests on the top side of the circuit board 3, with a heat conducting element 2 being arranged between the heat sink 1 and the circuit board 3.

[0057] The heat-conducting element 2 is designed, for example, as a thermally conductive paste or thermally conductive foil. For example, the thermally conductive foil is designed as a silicone foil or a ceramic foil, in particular as a silicone-free foil, or as a copper foil coated with a phase-change paste, in particular a phase-change paste.

[0058] The printed circuit board 3 has vias to which the heat-generating elements are connected on the one hand and the heat-conducting element 2 on the other hand, i.e. at the end of the vias facing away from the respective heat-generating element. Thus, the heat of the respective heat-generating element is efficiently dissipated to the heat sink 1 via the respective via and via the heat-conducting element 2.

[0059] The heat sink 1 is hollow, thus having a continuous recess, in particular one aligned parallel to the circuit board 3. A fan 9 is arranged on the front side of the heat sink 1, with the air flow required by the fan 9 flowing through the recess.

[0060] The heat sink 1 has inward-facing cooling fins which protrude into the air flow.

[0061] Preferably, the heat sink 1 is manufactured as an extruded profile. This allows the use of long screws 8, which are inserted through through holes or screwed into threaded holes in the heat sink 1, which extend in the solid material over the entire extent of the heat sink in the normal direction to the circuit board plane. This ensures high mechanical stability.

[0062] In particular, the outer circumference of the heat sink is cuboid-shaped.

[0063] Advantageously, a fan with a square housing can be connected to the heat sink 1 so that the air flow conveyed by the fan is completely guided in the heat sink 1.

[0064] Screws 8 protrude through the heat sink 1, the heat conducting element 2 and the circuit board 3 and are each screwed with their threaded area into a respective internal thread area of ​​a respective press-in nut 5, which is embedded in a plate part 7, in particular a pressure distribution plate.

[0065] The press-in nuts 5 are spaced from the circuit board 3.

[0066] The screw heads of the screws 8 press onto the heat sink 1 on the side facing away from the circuit board 3.

[0067] The plate part 7 is preferably made of steel. Alternatively, however, a design of the plate part 7 from another metal, such as aluminum, or even from ceramic or CFRP, in particular from carbon fiber reinforced plastic, would also be advantageous.

[0068] The circuit board 3 is preferably designed as a multilayer circuit board. A compensating element 6, in particular a pad, is arranged between the plate part 7 and the underside of the circuit board 3, including the heat-generating elements 20 mounted thereon, in particular power semiconductors.

[0069] When the screws 8 are tightened, the distance between the plate part 7 and the heat sink 1 is reduced, so that on the one hand the heat sink 1 presses onto the top side of the circuit board 3 via the heat conducting element 2 and on the other hand the plate part 7 presses onto the heat-generating components 20, in particular power semiconductors, via the compensating element 6.

[0070] In particular, the press-in nuts 5 on the plate part 7 protrude towards the circuit board 3, in particular through recesses 4 of the compensating element 6. However, the press-in nuts 5 are always spaced from the circuit board 3.

[0071] The plate part 7 is aligned parallel to the circuit board 3.

[0072] The compensating element 6 is made of electrically insulating, in particular insulation-resistant, material.

[0073] Polypropylene is particularly preferably selected as the material of the compensating element 6, since a cushion made from it compensates for the geometric tolerances when assembling the components 20, in particular power semiconductors, in particular the different distances between the plate part 7 and the components 20, in particular power semiconductors.

[0074] Alternatively, PTFE, especially Teflon, or even hard rubber can be used as the material for the compensating element 6.

[0075] In particular, the compensating element 6 has a lower stiffness than the plate part 7. In particular, the compensating element has a lower modulus of elasticity than the plate part.

[0076] The printed circuit board 3 optionally has an electrically insulating layer; alternatively or additionally, the heat-conducting element 2 is designed to be electrically insulating, so that the heat sink 1 is electrically connected to the screws 8 and the metallic plate part 7, but at a different potential than the conductor tracks of the printed circuit board 3. Alternatively, the heat-conducting element 2 is designed to be electrically conductive, so that the heat sink 1 is arranged at the same electrical potential as the top side of the printed circuit board or as the vias of the printed circuit board.

[0077] In further embodiments of the invention, a similarly acting fastening element, such as a rivet or a threaded bolt with nuts, is used instead of the respective screw 8. In any case, however, the distance between the heat sink 1 and the plate part 7 is reduced when the fastening element is attached.

[0078] In further embodiments according to the invention, in order to produce a heat-conducting connection between the components 20 and the heat-conducting element 2, a metal inlay pressed into the circuit board 3 is used instead of the through-plating or in addition to the through-plating and / or the material of the circuit board 3 is designed to be heat-conducting.

[0079] The heat sink 1 can be designed as an extruded aluminum profile part so that the drawing direction or extruded casting direction is aligned parallel to the circuit board 3.

[0080] In further embodiments according to the invention, the heat sink 1 is preferably made of heat-conducting ceramic or thermally conductive CFRP instead of aluminum. This makes it easier to maintain large insulation distances. Furthermore, the cooling fins, which may be made of brittle material, are arranged in a protected manner within the heat sink 1.

[0081] In further embodiments of the invention, the plate part 7 is preferably made of ceramic or CFRP instead of steel or aluminum. This makes it easier to maintain high insulation distances.

[0082] When assembling the circuit board, the distances between the plate part 7 and the components 20 are not identical, but rather different, due to manufacturing reasons. Some components therefore protrude slightly further from the plate part 7 than others. The force is transmitted from the plate part 7 to the components 20 through the compensating element, which exhibits such relaxation behavior that so much of the material of the compensating element 6 undergoes plastic deformation that the remaining elastic residue is ultimately elastically deflected by the compressive force of the plate part 7 in such a way that the spring force generated by the respective deflection of the respective elastic residue is essentially the same in each case.

[0083] In this way, as a result of this suitable relaxation behavior, each component is loaded with the essentially equal pressure transmitted from the plate part 7 via the compensating element 6, although the distances are different due to the manufacturing tolerances.

[0084] In particular, the plastic deformation of the compensating element between the plate part 7 and the respective component 20 is of different magnitude, in such a way that despite the different distances between the respective component 20 and the plate part 7, the spring force component exerted on the respective component 20 by the plate part 7 is of the same magnitude.

[0085] In further embodiments according to the invention, the compensating element 6 preferably has air pockets, so that the pressure introduced by the plate part 7 not only elastically deflects the material of the compensating element 6, but also the air pockets, which significantly influences the elasticity of the compensating element 6. It is important that a material that can withstand high pressure loads is selected as the material of the compensating element 6. Alternatively, the compensating element 6 can be porous, so that the elasticity of the compensating element 6 is essentially determined solely by the material of the compensating element 6. The pore size of the material can also be selected to be very small.

[0086] In further embodiments according to the invention, the compensating element has different wall thicknesses. In particular, components of different heights, as seen from the circuit board, can be touched by the compensating element. The compensating element thus bridges the different distances between the board part and the components. This makes it possible to equip different areas arranged parallel to the circuit board plane with components of different heights, but with components of the same height within each area, and to press all components together toward the heat sink using the same board part.

[0087] In further embodiments according to the invention, the plate part is simultaneously a housing part or at least shaped such that it surrounds the circuit board, in particular and the heat sink. The advantage here is that no separate component is required, but rather the rigidity of the housing is also used. In an alternative embodiment, the press-in nuts 5 are not spaced from the circuit board 3. This is particularly advantageous when connecting the plate part to a housing. This avoids mechanical overdetermination. The advantage of this embodiment is that the screws 8 have a defined stop, in that the press-in nuts 5 form a frictional connection with the circuit board and the heat sink.

[0088] The advantage of this is that the compensating element and the components are subjected to less mechanical stress, as part of the force generated by the screws is transferred to the circuit board via the compensating element and another part via the press-in nuts. The contact pressure on the components only needs to be as high as thermally necessary. Any forces exceeding this, which are necessary for mechanical stability of the connection, especially screw connections, are transferred to the mechanical stop.

[0089] In further embodiments according to the invention, an open heat sink can be used instead of the hollow heat sink 1, which consists of a plate-shaped base area to which

[0090] Cooling fins are molded in. The high heat capacity of the base area allows for efficient heat dissipation.

[0091] List of reference symbols

[0092] 1 Heat sink, hollow 2 Heat conducting element

[0093] 3 circuit board

[0094] 4 Recess

[0095] 5 press-in nut

[0096] 6 Compensating element, in particular cushion 7 Plate part, in particular pressure distribution plate

[0097] 8 screw

[0098] 9 fans

[0099] 20 Heat-generating component, especially power semiconductor

Claims

Patent claims:

1. Electrical device, comprising a printed circuit board, in particular a thermally conductive printed circuit board structure, equipped with at least heat-generating components, in particular power semiconductors, a heat sink, a heat-conducting element, a plate part and Fastening means, characterized in that on a first side, in particular the top side, of the circuit board, the heat sink rests against and / or is arranged on the circuit board, wherein the heat conducting element is interposed between the heat sink and the circuit board, in particular between the heat sink and the top side of the circuit board, in particular wherein the heat sink is thermally and / or thermally conductively connected to the circuit board by means of the heat conducting element, wherein the components are mounted on the side of the circuit board facing away from the heat sink, in particular the bottom side, and a compensating part is arranged between the plate part and the side of the circuit board facing away from the heat sink, in particular the bottom side, wherein the compensating element is arranged between the plate part and the components, in particular wherein the plate part is separated from the mounted circuit board, in particular from the heat-generating components mounted on the circuit board,is spaced apart by means of the compensating element, in particular wherein the heat sink is spaced apart from the circuit board by means of the heat conducting element., 2. Electrical device according to claim 1, characterized in that, in particular due to manufacturing tolerances, the distances between the plate part and the components are each different, in particular wherein a first of the components, viewed from the circuit board, protrudes more towards the plate part than a second of the components, wherein the material of the compensating element has a relaxation behavior such that a material portion of the compensating element is plastically deformed such that the elastic residue remaining between the plate part and the respective component is elastically deflected in such a way, in particular by the compressive force of the plate part, that the spring pressure force generated by this respective deflection of the respective elastic residue is essentially the same in each case.and / or that the material of the compensating element is plastically deformed and / or has such a relaxation behavior that each component is loaded with the substantially equal pressure transmitted from the plate part via the compensating element, in particular although the distances are different due to the manufacturing tolerances.

3. Electrical device according to one of the preceding claims, characterized in that the components are of identical construction and / or identical design within the scope of the manufacturing tolerances, in particular in height, and / or the components each have the same housing type, wherein the components each have different distances from the plate part, in particular which are caused by manufacturing tolerances when populating the circuit board with the components, and / or that components of different heights are distributed in different regions of the circuit board with components of the same height within a region, wherein the compensating element consists of several materials of different thicknesses, matching the component height of the respective region, and / or that the fastening means are screws or are designed as threaded bolts with a screwed-on nut,and / or that the compensating element has a lower stiffness than the plate part and / or that the compensating element has a lower modulus of elasticity than the plate part., 4. Electrical device according to one of the preceding claims, characterized in that the heat-conducting element comprises or is a heat-conducting paste, a phase-transition paste, a printed circuit board base material, a coated metal foil, a ceramic material, a silicone foil and / or a ceramic foil, in particular a silicone-free foil.

5. Electrical device according to one of the preceding claims, characterized in that the heat sink has continuous recesses, in particular through-holes, and that the fastening means protrude through the recesses of the heat sink, the printed circuit board and the compensating element.

6. Electrical device according to one of the preceding claims, characterized in that when the fastening means are actuated, in particular screwed, the distance between the heat sink and the plate part is reduced, in particular so that the heat sink is pressed towards the printed circuit board and the plate part is also pressed towards the printed circuit board.

7. Electrical device according to one of the preceding claims, characterized in that the fastening means are screw-connected to the plate part, in particular are screwed into an internal thread of the plate part or into an internal thread of a press-in nut connected to the plate part, and / or the fastening means each have a screw head or a nut on their end region facing away from the plate part, which in each case presses onto the heat sink.

8. Electrical device according to one of the preceding claims, characterized in that the fastening means are screwed into an internal thread of the heat sink or into an internal thread of a press-in nut connected to the heat sink, and / or that the fastening means each have a screw head which presses onto the plate part, in particular on the side of the plate part facing away from the heat sink.

9. Electrical device according to one of the preceding claims, characterized in that the plate part and / or the press-in nuts projecting on the plate part towards the circuit board are or are spaced from the circuit board by means of the components.

10. Electrical device according to one of the preceding claims, characterized in that the circuit board is populated on both sides. 11 . Electrical device according to one of the preceding claims, characterized in that the press-in nuts protrude through recesses of the compensating element, in particular and are spaced from the circuit board, in particular by means of the components.

12. Electrical device according to one of the preceding claims, characterized in that the heat sink has a continuous recess and / or is hollow, and / or that the heat sink has cooling fins projecting into the recess, and / or that the outer circumference of the heat sink is cuboid-shaped, and / or that the heat sink has a flat and / or level surface on its side facing the circuit board, and / or that the heat-conducting element is designed as a copper foil coated with phase transition paste, in particular phase change paste.

13. Electrical device according to one of the preceding claims, characterized in that a fan motor is arranged on the heat sink in such a way that the air flow conveyed by the fan flows through the recess of the heat sink, in particular wherein the fan and / or fan motor is fastened to the heat sink so that the heat sink together with the fan and / or fan motor is fastened to the circuit board and / or to the plate part by means of the fastening means, and / or that the plate part is designed as a housing part which houses the circuit board, the heat sink and / or the fan and / or surrounds them in a housing-forming manner.

14. Electrical device according to one of the preceding claims, characterized in that the printed circuit board has a heat conducting means, in particular thermal via, wherein the components rest on the heat conducting means on the one hand and the heat conducting element, which touches the heat sink, on the other hand, i.e. at the end of the heat conducting means facing away from the components, wherein the heat conducting means is designed as a through-hole connection and / or as a metal inlay pressed into the printed circuit board and / or that the printed circuit board has an electrically insulating layer as the base material of the printed circuit board, which layer has a specific thermal conductivity of more than 1 W / (m K), in particular 1 watt per meter and per Kelvin.

15. Electrical device according to one of the preceding claims, characterized in that the compensating element is made of polypropylene, in particular of porous expanded polypropylene, in particular PEPP, or of Teflon or of rubber, and / or that the compensating element has air inclusions or is porous, and / or that the press-in nuts are not spaced from the circuit board and the plate part forms a force connection with the circuit board and the heat sink, wherein the pressure caused by the fastening means is distributed between the force connection and the pressure on the components via the compensating element, wherein the pressure on the components is thereby reduced to the thermally necessary level.

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