Coil component

Abstract

The invention relates to a coil assembly (1), comprising: a circuit carrier (2); an electric coil (5), the winding (7) of which is wound on the magnetic core (6) and passes through the inner opening (6.1); the at least two turns (8) each have an electrically conductive conductor part (8.1) with two end parts (8.2, 8.3), which are each inserted into the electrical through-contacts (4) and are in contact therewith, and wherein the cooling assembly (10) has a plurality of first electrically conductive structures (3, 11) on the coil-facing surface of the circuit carrier (2) in the region of the magnetic core (6), the first conductive structures (3, 11) are thermally coupled to a plurality of corresponding second conductive structures (13, 14) on a surface of the circuit carrier (2) facing away from the coil by means of at least one thermal through-contact (12), the first conductive structures (3, 11) being arranged at a distance from one another and each being connected to at least one electrical through-contact (4), the second line structures (13, 14) are arranged at a distance from each other and are thermally coupled to at least one cooling element (18) arranged on the surface of the circuit carrier (2) facing away from the coil, such that a cooling path is formed between the end pieces (8.2, 8.3) of the at least two turns (8), which are in contact with the corresponding electrical through-contact (4), and the at least one cooling element (18).

Description

TECHNICAL FIELD

[0001] The invention relates to a coil assembly having a circuit carrier and at least one electric coil, the winding of which is wound around a magnetic core surrounding at least one inner opening in at least two turns and passes through the at least one inner opening. BACKGROUND

[0002] From the document DE 10 2016 210 746 A1 an inductive structural element is known, which has a ring-shaped core piece made of a magnetically soft material, which ring- shaped core piece surrounds an inner opening in a ring shape, and at least two electrically conductive conductor pieces which pass through the inner opening, but do not completely surround the ring-shaped core piece, each of which has two conductor end sections. The conductor end sections are guided away from the ring-shaped core piece in a manner parallel to one another and perpendicular to the ring-shaped core piece and are electrically connected to one another to form at least one winding. The conductor end sections are arranged outside the inner opening and outside an imaginary extension of the inner opening in the axial direction. The inductive structural element is arranged on an electrically insulating carrier plate with a hole, which electrically insulating carrier plate has an electrically conductive structure at least in the vicinity of the hole. The conductor end sections of the conductor pieces are guided through the hole and electrically connected to one another by the electrically conductive structure to form at least one winding. SUMMARY

[0003] The coil assembly having the features of independent claim 1 has the advantage that the cooling of the at least one electric coil is achieved by the circuit carrier. Here, a cooling path for the individual turns of the at least one electric coil can be established by a thermal connection through the circuit carrier to at least one cooling element arranged on the surface of the circuit carrier facing away from the coil. The at least one cooling element can be arranged on the surface of the circuit carrier facing away from the coil, preferably within the area covered by the at least one electric coil. Additionally or alternatively, the at least one cooling element can be arranged on the surface of the circuit carrier facing away from the coil, outside the area covered by the at least one electric coil. Furthermore, the embodiments of the invention enable an additional cooling of the at least one coil on the side of the at least one coil facing away from the circuit carrier, on which side further cooling elements can be placed on the winding of the at least one coil.

[0004] The electrical contacting of the turns of the at least one coil on the circuit carrier is advantageously improved by the individual cooling paths for heat dissipation, so that the power dissipation of the at least one coil can be increased. Thereby a higher power density or packaging density can be achieved and thus a reduced installation space requirement. Furthermore, with the same installation space requirement, the scalability of the design of the heat-conducting structure of the at least one coil and the circuit carrier and of the cooling paths of each individual turn can be achieved.

[0005] Embodiments of the present application provide a coil assembly comprising an electrical circuit carrier, at least one electrical coil with a winding wound in at least two turns around a magnetic core encompassing at least one inner opening and passing through the at least one inner opening, and at least one cooling assembly. The at least two turns each have an electrically conductive conductor piece with two end pieces which are each inserted into and in contact with an electrical through-contact introduced into the electrical circuit carrier. Here, the cooling assembly has at least two first thermally conductive structures on a coil-facing surface of the electrical circuit carrier in the region of the magnetic core, which are thermally coupled via at least one thermal through-contact to at least two associated second thermally conductive structures on a coil-facing surface of the electrical circuit carrier. The at least two first thermally conductive structures are arranged spaced apart from one another and each connected to at least one of the electrical through-contacts, and the at least two second thermally conductive structures are arranged spaced apart from one another and thermally coupled to at least one cooling element arranged on the coil-facing surface of the electrical circuit carrier, so that a cooling path is formed between the end pieces of the at least two turns in contact with the corresponding electrical through-contacts and the at least one cooling element, respectively.

[0006] In the present case, the magnetic core can be understood as a circular, oval or rectangular ring-shaped core piece, with or without a central connecting plate, which is preferably made of a soft magnetic material.

[0007] Embodiments of the coil assembly according to the application can be used as interference-suppressing chokes for electrical and electronic circuits, for example in high-voltage or high-current applications. Such interference-suppressing chokes are preferably used to suppress interference currents occurring in the same direction in the forward and reverse direction. Such current-compensating chokes can also be referred to as common mode chokes and have a plurality of identical and oppositely directed windings in terms of the throughflow of the operating current. In ideally symmetrical windings with the same number of turns and the same wiring, the magnetic fields of the individual windings in the magnetic core of the choke thus cancel each other out, so that the choke has a low inductance for the operating current, while the inductance of the choke for interference currents occurring in the same direction is significantly higher.

[0008] In the present case, the electrical through-contact can be understood as a continuous opening in the electrical circuit carrier with an electrically conductive wall or sleeve. The individual end pieces of the turns can be inserted into such an electrical through-contact and soldered to the wall or sleeve of the through-contact and the thermally conductive structures of the electrical circuit carrier in a subsequent soldering process. The cross-sectional area of the electrically conductive wall or sleeve and the cross-sectional area of the end pieces of the individual turns can here preferably be chosen such that a circumferential gap is formed between the inserted end pieces and the electrically conductive wall or sleeve of the electrical through-contact, which facilitates the insertion of the end pieces and allows the solder to pass through when soldering. Furthermore, the thermally conductive structures in the region of the electrical through-contact have a certain minimum width. The thermally conductive structures on the coil-facing surface and the coil-facing surface of the electrical circuit carrier can each be made of a material which is good at conducting heat and electricity, for example copper.

[0009] The measures and refinements listed in the dependent claims make possible advantageous improvements to the coil assembly presented in independent claim 1.

[0010] It is particularly advantageous if the circuit carrier can be designed as a multilayer printed circuit board having at least one electrically and thermally conductive inner layer, which is connected to at least one thermal through-contact and to at least one electrical through-contact. Here, the number and thickness of the respective electrically and thermally conductive inner layers, which are preferably made of copper, and of the corresponding insulating layers can be selected and specified in accordance with statutory standards, in order to activate and optimize the cooling paths of the individual turns of the at least one coil.

[0011] In one advantageous design of the coil assembly, the electrically conductive conductor pieces of the at least two turns can each be designed in the shape of a U. Here, one of the two end pieces of the at least two turns can be designed as a straight electrically conductive conductor piece, while the other of the two end pieces can be designed as an S-shaped electrically conductive conductor piece, wherein the sections of the two end pieces of the at least two turns inserted into the electrical through-contacts are parallel to each other in the axial direction outside the at least one inner opening and outside the imaginary extension of the at least one inner opening. This makes it possible to realize a particularly compact configuration of the coil assembly.

[0012] In another advantageous design of the coil assembly, at least one of the at least two first thermally conductive structures on the surface of the circuit carrier facing the coil can electrically connect two electrical through-contacts into which the end pieces of two adjacent turns of the winding of the at least one coil are respectively inserted to each other, so that the two adjacent turns of the winding of the at least one electrical coil are electrically connected in series. Thus, for example, the first end piece can form an input contact of the corresponding turn. The second end piece can form an output contact of the corresponding turn. This means that the second end piece, which forms an output contact of the first turn and is inserted into and in electrical contact with the first through-contact, is thermally and electrically connected by the corresponding first thermally conductive structure to the second through-contact into which the first end piece, which forms an input contact of the second turn, is inserted and in electrical contact with. Here, the second end piece of the first turn and the first end piece of the second turn can each be soldered to the corresponding through-contact.

[0013] Alternatively, at least one of the at least two first heat-conducting structures on the coil-facing surface of the circuit carrier can have an electrical through-contact designed as a slot into which two end pieces of adjacent turns of the winding of the at least one coil can be inserted and electrically connected to one another, such that the two adjacent turns of the winding of the at least one coil are electrically connected in series. This means that a second end piece forming an output contact of a first turn and a first end piece forming an input contact of a second turn can be inserted into and in electrical contact with the same through-contact. Here, the second end piece of the first turn and the first end piece of the second turn can be soldered to the same through-contact. By means of such an electrical through-contact designed as a slot, the two end pieces of the adjacent turns can be easily electrically and thermally connected to one another. Furthermore, due to the small distance between the two end pieces, the overall diameter of the coil assembly can be reduced. This enhances the electrical connectivity by means of the direct contact formed by the solder to the two end pieces and the material of the wall of the through-contact designed as a slot.

[0014] In a further advantageous design of the coil assembly, at least one of the at least two first heat-conducting structures can have a connection for an electrical structural element. Thus, for example, a smoothing capacitor, an ohmic resistor or a contact terminal can be easily arranged between two turns of the at least one coil.

[0015] In a further advantageous design of the coil assembly, a first end piece of a first turn of the winding can form a first contact or an input contact of the at least one coil, and a second end piece of a last turn of the winding can form a second contact or an output contact, and the two end pieces can be inserted into and in contact with an electrical through-contact designed as a hole, respectively.

[0016] In a further advantageous design of the coil assembly, the at least two first heat-conducting structures can be formed on a free surface of the coil-facing surface of the circuit carrier, in the direction towards the at least one inner opening and below the magnetic core and / or outside the magnetic core in the direction away from the magnetic core. Especially when formed in the direction towards the magnetic core, the unused area below the magnetic core can be used for the first heat-conducting structures in a space-saving manner. Depending on the size of the circuit carrier, the first heat-conducting structures can also be formed outside the magnetic core in the vicinity thereof.

[0017] In a further advantageous design of the coil assembly, the shape and size of the at least one inner layer of the circuit carrier and the number of the thermal through-contacts can be adapted to the thermal load conditions. Advantageously, it is thereby possible to easily form individual cooling paths for cooling individual turns of the at least one coil optimally to the thermal conditions of the coil assembly.

[0018] In a further advantageous design of the coil assembly, at least one electrically insulating thermally conductive layer can be introduced between the at least one cooling element on the surface of the circuit carrier facing away from the coil and the at least two second thermally conductive structures. Here, the area of the electrically insulating thermally conductive layer can be greater than the area of the at least two second thermally conductive structures, which in turn can be greater than the area of the at least one cooling element. In order to compensate for the inhomogeneity and to improve the heat transfer, a good thermally conductive layer can be introduced between the electrically insulating thermally conductive layer and the at least one cooling element.

[0019] In a further advantageous design of the coil assembly, in order to avoid a creepage distance between the at least one electrically through-going contact and the at least one cooling element arranged on the surface of the circuit carrier facing away from the coil, the edge of the at least one cooling element can have a first minimum distance to the at least one electrically through-going contact, the edge of the at least one thermally through-going contact can have a second minimum distance to the at least one electrically through-going contact, which is smaller than the first minimum distance, the edge of the at least two second thermally conductive structures can have a third minimum distance to the at least one electrically through-going contact, which is smaller than the second minimum distance, and the edge of the electrically insulating thermally conductive layer can have a fourth minimum distance to the at least one electrically through-going contact, which is smaller than the third minimum distance. Here, the selection and specification of these minimum distances takes into account legal standards.

[0020] In a further advantageous design of the coil assembly, the cooling assembly can comprise at least one further cooling element, which can be placed on the winding of the at least one coil on the side of the at least one coil facing away from the circuit carrier. Here, the at least one further cooling element can be thermally coupled to the winding of the at least one coil by means of at least one electrically insulating thermally conductive structure. In addition to being able to cool the individual turns of the at least one electric coil of the coil assembly "downwards" by means of the circuit carrier, the at least one further cooling element can advantageously also cool the at least one coil of the coil assembly "upwards".

[0021] Embodiments of the application are illustrated in the accompanying drawings and explained in more detail in the following description. In the drawings, identical reference signs denote parts or elements that perform the same or similar functions. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 A schematic perspective view of a first embodiment of a coil assembly according to the application is shown.

[0023] Figure 2 A schematic perspective view of a second embodiment of a coil assembly according to the application is shown. Figure 1 A schematic top view of a coil assembly according to the application is shown, without a magnetic core.

[0024] Figure 3 A schematic top view of a coil assembly according to the application is shown, with a magnetic core. Figure 1 and Figure 2Schematic perspective view of two adjacent windings of a coil assembly according to the present application.

[0025] Figure 4 Schematic perspective view of a coil assembly according to the present application is shown. Figure 1 and Figure 2 Schematic top view of a portion of a circuit carrier of a coil assembly according to the present application is shown.

[0026] Figure 5 Schematic perspective view of a coil assembly according to the present application is shown. Figure 1 and Figure 2 Schematic sectional view of a portion of a circuit carrier of a coil assembly according to the present application is shown.

[0027] Figure 6 Schematic top view of a circuit carrier of a coil assembly according to the present application is shown, with an uncharged coil. Figure 1 and Figure 2 Schematic top view of a circuit carrier of a coil assembly according to the present application is shown, with an uncharged coil.

[0028] Figure 7 Schematic view from below of a circuit carrier of a coil assembly according to the present application is shown, with no cooling element and no electrically insulating thermally conductive layer. Figure 1 and Figure 2 Schematic view from below of a circuit carrier of a coil assembly according to the present application is shown, with no cooling element and no electrically insulating thermally conductive layer.

[0029] Figure 8 Schematic view from below of a circuit carrier of a coil assembly according to the present application is shown. Figure 1 and Figure 2 Schematic view from below of a circuit carrier of a coil assembly according to the present application is shown.

[0030] Figure 9 Schematic perspective partial sectional view of a second embodiment of a coil assembly according to the present application is shown, with no magnetic core. DETAILED DESCRIPTION

[0031] From Figures 1 to 9It can be seen that the shown embodiments of the coil assembly 1, 1A, 1B according to the application each comprise a circuit carrier 2, at least one electrical coil 5 whose winding 7 is wound in at least two turns 8 on a magnetic core 6 surrounding at least one inner opening 6.1 and through the at least one inner opening 6.1, and at least one cooling assembly 10, 10A, 10B. The at least two turns 8 each have an electrically conductive conductor piece 8.1 with two end pieces 8.2, 8.3, which are each inserted into and in contact with an electrical through-contact 4 introduced into the circuit carrier 2. Here, the cooling assembly 10, 10A, 10B has at least two first thermally conductive structures 3, 11 on a coil-facing surface of the circuit carrier 2 in the region of the magnetic core 6, which are thermally coupled to at least two corresponding second thermally conductive structures 13, 14 on a coil-facing surface of the circuit carrier 2 by at least one thermal through-contact 12. The at least two first thermally conductive structures 3, 11 are arranged spaced apart from one another and are each connected to at least one electrical through-contact 4, while the at least two second thermally conductive structures 13, 14 are arranged spaced apart from one another and are thermally coupled to at least one cooling element 18 arranged on a coil-facing surface of the circuit carrier 2, so that a cooling path is formed between the end pieces 8.2, 8.3 of the at least two turns 8, which are in contact with the respective electrical through-contact 4, and the at least one cooling element 18.

[0032] It can further be seen from Figure 1 that the coil assembly 1 is designed as a common-mode choke for high-voltage or high-current applications. To this end, the magnetic core 6 in the shown embodiment is designed as a circular ring-shaped core piece 6A having an inner opening 6.1 and is oriented parallel to a surface of the circuit carrier 2. In the shown embodiment, the winding 7 of two electrical coils 5 is wound on this ring-shaped core piece 6A. Here, a first coil 5A comprises a first winding 7A having five turns 8A, 8B, 8C, 8D, 8E. A second coil 5B is configured symmetrically to the first coil 5A and comprises a second winding 7B likewise having five turns 8A, 8B, 8C, 8D, 8E. In principle, only one coil or more than two coils can also be arranged.

[0033] In a not shown alternative embodiment of the coil assembly 1, the magnetic core 6 is designed as an elliptical or rectangular ring-shaped core piece 6A having an inner opening 6.1. In a not shown further alternative embodiment, the ring-shaped core piece 6A has a central connecting plate, so that the respective magnetic core 6, regardless of its shape, has two inner openings.

[0034] It can be seen in particular from Figure 5 that the circuit carrier 2 in the shown embodiment is designed as a multilayer printed circuit board 2A, for example having four electrically conductive and thermally conductive inner layers 2.1, which are connected to at least one thermal through-contact 12 and at least one electrical through-contact 4.

[0035] From Figures 1 to 3 and Figure 9 It can further be seen that the electrically conductive conductor pieces 8.1 of the five turns 8A, 8B, 8C, 8D, 8E of the respective coil 5A, 5B are designed in an exemplary manner each as a U. Here, the first end piece 8.2 is designed as an electrically conductive conductor piece in the shape of an S and forms an input contact of the respective turn 8A, 8B, 8C, 8D, 8E. The second end piece 8.3 is designed as an electrically conductive conductor piece in the shape of a straight line and forms an output contact of the respective winding 8A, 8B, 8C, 8D, 8E. The sections of the two end pieces 8.2, 8.3 of the respective turn 8A, 8B, 8C, 8D, 8E that are inserted into the electric through-contact 4 extend parallel to each other in the axial direction outside the at least one inner opening 6.1 and outside the imaginary extension of the at least one inner opening 6.1. It can in particular be seen from Figure 1 , Figure 2 and Figures 6 to 8 It can further be seen that the through-contact 4 in the shown embodiment is located on the same circle around the magnetic core 6.

[0036] It can in particular be seen from Figure 1 , Figure 2 and Figure 6 that in the shown embodiment, by way of example only, six first heat-conducting structures 3, 11 are arranged on the coil-facing surface of the circuit carrier 2 for each coil 5A, 5B. Here, four of the first heat-conducting structures 11 each have the shape of a cake slice and have an electric through-contact 4 designed as a long hole 4B into which two end pieces 8.2, 8.3 of two adjacent turns 8A, 8B, 8C, 8D, 8E of the winding 7 of the respective coil 5 are respectively inserted and electrically connected to each other, such that the two adjacent turns 8A, 8B, 8C, 8D, 8E of the winding 7 of the respective coil 5 are electrically connected in series. The first heat-conducting structures 11 in the shape of a cake slice are arranged on the free face of the coil-facing surface of the circuit carrier 2 in the direction of the at least one inner opening 6.1 below the magnetic core 6. Two of the first heat-conducting structures 3 each have the shape of a web and a through-contact 4 designed as a hole 4A. The first heat-conducting structures 3 in the shape of a web are formed outside the magnetic core 6 in the direction away from the magnetic core 6.

[0037] Figure 4 An alternative design of the first heat-conducting structures 11 in the shape of a cake slice is shown. Here, the first heat-conducting structures 11 in the shape of a cake slice are formed on the free face of the coil-facing surface of the circuit carrier 2 in the direction of the at least one inner opening 6.1 below and outside the magnetic core 6, which is indicated in dashed lines.

[0038] From Figure 1 and Figure 2It can further be seen that a first end piece 8.2 of a first turn 8A of the first winding 7A of the first coil 5A is inserted into an electric through-contact 4, which is designed as a hole 4A in the web-shaped first heat-conducting structure 3A arranged in the upper left in the figure, and forms a first contact of the first coil 5A, which here corresponds to an input contact of the first coil 5A. A second end piece 8.3 of the first turn 8A of the first coil 5A is inserted together with a first end piece 8.2 of a second turn 8B of the first coil 5A into an electric through-contact 4, which is designed as a long hole 4B in the cake piece-shaped heat-conducting structure 11. A second end piece 8.3 of the second turn 8B of the first coil 5A is inserted together with a first end piece 8.2 of a third turn 8C of the first coil 5A into an electric through-contact 4, which is designed as a long hole 4B in the cake piece-shaped heat-conducting structure 11. A second end piece 8.3 of the third turn 8C of the first coil 5A is inserted together with a first end piece 8.2 of a fourth turn 8D of the first coil 5A into an electric through-contact 4, which is designed as a long hole 4B in the cake piece-shaped heat-conducting structure 11. A second end piece 8.3 of the fourth turn 8D of the first coil 5A is inserted together with a first end piece 8.2 of a fifth turn, i.e. the last turn, 8E of the first coil 5A into an electric through-contact 4, which is designed as a long hole 4B in the cake piece-shaped heat-conducting structure 11. A second end piece 8.3 of the fifth turn, i.e. the last turn, 8E of the first coil 5A is inserted into and in contact with an electric through-contact 4, which is designed as a hole 4A in the web-shaped heat-conducting structure 3B arranged in the upper right in the figure, and forms a second contact of the first coil 5A, which here corresponds to an output contact of the first coil 5A. For embodiments with more or fewer turns, the same applies.

[0039] From Figure 1 and Figure 2It can further be seen that the first end piece 8.2 of the first turn 8A of the second winding 7B of the second coil 5B is inserted into the electric through-contact 4, which is designed as a hole 4A, of the web-shaped first heat-conducting structure 3A arranged in the lower right in the figure and forms a first contact of the second coil 5B, which here corresponds to an input contact of the second coil 5B. The second end piece 8.3 of the first turn 8A of the second coil 5B, together with the first end piece 8.2 of the second turn 8B of the second coil 5B, is inserted into the electric through-contact 4, which is designed as a long hole 4B, of the cake piece-shaped heat-conducting structure 11. The second end piece 8.3 of the second turn 8B of the second coil 5B, together with the first end piece 8.2 of the third turn 8C of the second coil 5B, is inserted into the electric through-contact 4, which is designed as a long hole 4B, of the cake piece-shaped heat-conducting structure 11. The second end piece 8.3 of the third turn 8C of the second coil 5B, together with the first end piece 8.2 of the fourth turn 8D of the second coil 5B, is inserted into the electric through-contact 4, which is designed as a long hole 4B, of the cake piece-shaped heat-conducting structure 11. The second end piece 8.3 of the fourth turn 8D of the second coil 5A, together with the first end piece 8.2 of the fifth turn, i.e. the last turn, 8E of the second coil 5B, is inserted into the electric through-contact 4, which is designed as a long hole 4B, of the cake piece-shaped heat-conducting structure 11. The second end piece 8.3 of the fifth turn, i.e. the last turn, 8E of the second coil 5B is inserted into the electric through-contact 4, which is designed as a hole 4A, of the web-shaped heat-conducting structure 3B arranged in the lower left in the figure and comes into contact with it and forms a second contact of the second coil 5B, which here corresponds to an output contact of the second coil 5B. An electrical load, for example an inverter of a three-phase motor, can be connected between the web-shaped heat-conducting structure 3B arranged in the upper right in the figure, which is connected to the output contact of the first coil 5A, and the web-shaped heat-conducting structure 3A arranged in the lower right in the figure, which is connected to the input contact of the second coil 5B. A direct voltage source can be connected at each of the two web-shaped heat-conducting structures 3 arranged on the left in the figure. Thus, for example, a positive direct voltage source can be arranged at the web-shaped heat-conducting structure 3A arranged in the upper left in the figure, which is connected to the input contact of the first coil 5A. For example, a negative direct voltage source can be connected to the web-shaped heat-conducting structure 3B arranged in the lower left in the figure, which is connected to the output contact of the second coil 5B. Embodiments with a greater or smaller number of turns are implemented in the same way.

[0040] In the embodiment shown, the electric through-contacts 4 have an electrically conductive wall 4.1 or sleeve, to which the inserted respective end pieces 8.2, 8.3 of the turns 8A, 8B, 8C, 8D, 8E of the two coils 5A, 5B are connected by material connection 9, preferably by soldering.

[0041] In a not shown alternative embodiment of the coil assembly 1, the four cake block shaped first heat conducting structures 1 1 of the two coils 5A, 5B have two electrical through contacts 4 each designed as a hole 4A on the coil facing surface of the circuit carrier 2 into which the end pieces 8.2, 8.3 of two adjacent turns 8A, 8B, 8C, 8D, 8E of the winding 7 of the respective coil 5A, 5B are inserted. Here, the cake block shaped first heat conducting structures 1 1 connect the two adjacent turns 8A, 8B, 8C, 8D, 8E of the respective coil 5A, 5B in such a way that they are electrically connected in series.

[0042] It can further be taken from Figure 6 that the cake block shaped first heat conducting structures 1 1 of the two coils 5A, 5B have a contact 1 1.1 for an electrical construction element C each. In the shown embodiment, the two electrical construction elements C correspond to a smoothing capacitor each.

[0043] It can further be taken from Figure 7 that in the shown embodiment of the coil assembly 1 A, on the coil facing surface of the circuit carrier 2, six second heat conducting structures 13, 14 are arranged for each coil 5A, 5B (only as an example) each. Here, the four second heat conducting structures 14 of the respective coil 5A, 5B have the shape of a cake block each and are thermally connected to the cake block shaped first heat conducting structures 1 1 on the coil facing surface of the circuit carrier 2 by a plurality of thermal through contacts 12. The second heat conducting structures 12 shaped as a cake block are arranged on the free surface of the coil facing surface of the circuit carrier 2, in the direction of the at least one inner opening 6.1, below the magnetic core 6. Two of the second heat conducting structures 13 of the respective coil 5A, 5B have the shape of a web each and are thermally connected to the web shaped first heat conducting structures 3 on the coil facing surface of the circuit carrier 2 by a plurality of thermal through contacts 12. The web shaped second heat conducting structures 13 are formed outside of the magnetic core 6 in the direction away from the magnetic core 6.

[0044] It can further be taken from Figure 5 and Figure 8 that on the coil facing surface of the circuit carrier 2, between the at least one cooling element 18 and the at least two second heat conducting structures 13, 14, at least one electrically insulating thermally conducting layer 15 is introduced. Here, the area of the electrically insulating thermally conducting layer 15 is larger than the area of the at least two second heat conducting structures 13, 14, which in turn is larger than the area of the at least one cooling element 18. It can in particular be taken from Figure 8It can further be seen that in the shown embodiment the first cooling element 18 arranged below the magnetic core 6 is designed as a circular cooling dome 18A. In the shown embodiment the further cooling elements 18 arranged outside the magnetic core 6 are each designed as a quaderförmig cooling block 18B.

[0045] From Figure 5 It can further be seen that the edge of the cooling element 18 designed as a cooling dome 18A has a first minimum distance MA1 to the shown electrical feed-through contact 4. The edge of the thermal feed-through contact 12 arranged closest to the electrical feed-through contact has a second minimum distance MA2 to the electrical feed-through contact 4, which is smaller than the first minimum distance MA1. The edge of the second thermally conductive structure 14 has a third minimum distance MA3 to the electrical feed-through contact 4, which is smaller than the second minimum distance MA2. The edge of the electrically insulating thermally conductive layer 15 has a fourth minimum distance MA4 to the at least one electrical feed-through contact 4, which is smaller than the third minimum distance MA3. Here, the selection and specification of the minimum distances MA1, MA2, MA3, MA4 takes into account legal standards in order to avoid creepage distances in high-voltage or high-current applications. In order to compensate for inhomogeneities and to improve heat transfer, in the shown embodiment a good thermally conductive layer 16 is introduced between the electrically insulating thermally conductive layer 15 and the at least one cooling element 18.

[0046] The shape and size of the first thermally conductive structures 3, 11 on the coil-facing surface of the circuit carrier 2, the second thermally conductive structures 13, 14 on the coil-facing surface of the circuit carrier 2 and the inner layer 2.1 of the circuit carrier 2 as well as the number of thermal feed-through contacts 12 are adjusted according to the thermal load conditions.

[0047] From Figure 9 It can further be seen that the shown second embodiment of the coil assembly 1B essentially corresponds to the shown first embodiment of the coil assembly 1A and thus a repeated description of identical components is omitted. Unlike the first embodiment of the coil assembly 1A, the second embodiment of the cooling assembly 10B of the shown second embodiment of the coil assembly 1B has at least one further cooling element 19 placed on the winding 7 of the at least one coil 5 on the side of the at least one coil 5 facing away from the circuit carrier 2. In order to improve heat transfer, the shown further cooling element 19 is thermally coupled to the winding 7 of the at least one coil 5 by at least one electrically insulating thermally conductive structure 20. Figures 1 to 8 It can further be seen that the shown second embodiment of the coil assembly 1B essentially corresponds to the shown first embodiment of the coil assembly 1A and thus a repeated description of identical components is omitted. Unlike the first embodiment of the coil assembly 1A, the second embodiment of the cooling assembly 10B of the shown second embodiment of the coil assembly 1B has at least one further cooling element 19 placed on the winding 7 of the at least one coil 5 on the side of the at least one coil 5 facing away from the circuit carrier 2. In order to improve heat transfer, the shown further cooling element 19 is thermally coupled to the winding 7 of the at least one coil 5 by at least one electrically insulating thermally conductive structure 20.

Claims

1. A coil assembly (1) comprising: Circuit carrier (2); at least one electric coil (5), a winding (7) of which is wound in at least two turns (8) on a magnetic core (6) surrounding at least one inner opening (6.1) and through the at least one inner opening (6.1), and at least one cooling assembly (10), wherein the at least two turns (8) each have an electrically conductive conductor piece (8.1) with two end pieces (8.2, 8.3), which are each inserted into and in contact with an electrical through-contact (4) introduced into the circuit carrier (2), wherein the cooling assembly (10) has at least two first thermally conductive structures (3, 11) on a coil-facing surface of the circuit carrier (2) in the region of the magnetic core (6), which are thermally coupled to corresponding at least two second thermally conductive structures (13, 14) on a coil- facing surface of the circuit carrier (2) by at least one thermal through-contact (12), wherein the at least two first thermally conductive structures (3, 11) are arranged spaced apart from one another and each connected to at least one of the electrical through-contacts (4), and the at least two second thermally conductive structures (13, 14) are arranged spaced apart from one another and thermally coupled to at least one cooling element (18) arranged on the coil-facing surface of the circuit carrier (2), so that a cooling path is formed between the end pieces (8.2, 8.3) of the at least two turns (8) in contact with the corresponding electrical through-contacts (4) and the at least one cooling element (18), respectively.

2. The coil assembly (1) according to claim 1, characterized in that The circuit carrier (2) is designed as a multilayer printed circuit board (2A) having at least one electrically conductive, thermally conductive inner layer (2.1) connected to the at least one thermal through-contact (12) and the at least one electrical through-contact (4).

3. The coil assembly (1) according to claim 1 or 2, characterized in that The electrically conductive conductor pieces (8.1) of the at least two turns (8) are each designed in a U shape, wherein one of the two end pieces (8.2, 8.3) of the at least two turns (8) is designed as a straight electrically conductive conductor piece, and the other of the two end pieces (8.2, 8.3) of the at least two turns (8) is designed as an S-shaped electrically conductive conductor piece, wherein the sections of the two end pieces (8.2, 8.3) of the at least two turns (8) inserted into the electrical through-contacts (4) extend parallel to one another in the axial direction outside the at least one inner opening (6.1) and outside an imaginary extension of the at least one inner opening (6.1).

4. The coil assembly (1) according to any one of claims 1 to 3, characterized in that At least one of the at least two first thermally conductive structures (11) on the coil-facing surface of the circuit carrier (2) electrically connects two electrical through-contacts (4) into which end pieces (8.2, 8.3) of two adjacent turns (8) of the winding (7) of the at least one coil (5) are respectively inserted to one another, so that the two adjacent turns (8) of the winding (7) of the at least one coil (5) are electrically connected in a series connection.

5. The coil assembly (1) according to any one of claims 1 to 3, characterized in that At least one first thermally conductive structure (11) of the at least two first thermally conductive structures on the coil-facing surface of the circuit carrier (2) has an electrical through-contact (4) designed as a slot (4B), two end pieces (8.2, 8.3) of two adjacent turns (8) of the winding (7) of the at least one coil (5) are inserted into the electrical through-contact and are electrically connected to each other, so that the two adjacent turns (8) of the winding (7) of the at least one coil (5) are electrically connected in series.

6. The coil assembly (1) according to claim 4 or 5, characterized in that At least one first thermally conductive structure (11) of the at least two first thermally conductive structures has a connection (11.1) for an electrical structure element (C).

7. The coil assembly (1) according to any one of claims 1 to 6, characterized in that One end piece (8.2, 8.3) of a first turn (8A) of the winding (7) forms a first contact of the at least one coil (5), one end piece (8.2, 8.3) of a last turn (8E) of the winding (7) forms a second contact of the at least one coil (5), and both end pieces are inserted into and in contact with an electrical through-contact (4) designed as a slot (4A).

8. The coil assembly (1) according to any one of claims 1 to 7, characterized in that The at least two first thermally conductive structures (3, 11) are formed on the free surface of the coil-facing surface of the circuit carrier (2) in the direction of the at least one inner opening (6.1) and below the magnetic core (6) and / or in the direction away from the magnetic core (6) and outside the magnetic core (6).

9. The coil assembly (1) according to any one of claims 1 to 8, characterized in that The magnetic core (6) is designed as a circular, oval or rectangular ring core piece (6A) with or without a central web.

10. The coil assembly (1) according to any one of claims 2 to 9, characterized in that The shape and size of the at least two first thermally conductive structures (3, 11) on the coil-facing surface of the circuit carrier (2), the at least two second thermally conductive structures (13, 14) on the coil-facing surface of the circuit carrier (2) and the at least one inner layer (2.1) of the circuit carrier (2) and the number of the thermal through-contacts (12) can be adapted to the thermal load conditions.

11. The coil assembly (1) according to any one of claims 1 to 10, characterized in that At least one electrically insulating thermally conductive layer (15) is introduced between the at least one cooling element (18) and the at least two second thermally conductive structures (13, 14) on the coil-facing surface of the circuit carrier (2).

12. The coil assembly (1) according to claim 11, characterized in that The area of the electrically insulating thermally conductive layer (15) is greater than the area of the at least two second thermally conductive structures (13, 14), which is greater than the area of the at least one cooling element (18).

13. The coil assembly (1) according to claim 11 or 12, characterized in that An edge of the at least one cooling element (18) has a first minimum distance (MA1) to the at least one electric through-contact (4), an edge of the at least one thermal through-contact (12) has a second minimum distance (MA2) to the at least one electric through-contact (4) which is smaller than the first minimum distance (MA1), an edge of the at least two second thermally conductive structures (14) has a third minimum distance (MA3) to the at least one electric through-contact (4) which is smaller than the second minimum distance (MA2), and an edge of the electrically insulating thermally conductive layer (15) has a fourth minimum distance (MA4) to the at least one electric through-contact (4) which is smaller than the third minimum distance (MA3).

14. The coil assembly (1) according to any one of claims 1 to 13, characterized in that The cooling assembly (10) comprises at least one further cooling element (19) which is placed on a winding (7) of the at least one coil (5) on a side of the at least one coil (5) facing away from the circuit carrier (2).

15. The coil assembly (1) according to claim 14, characterized in that The at least one further cooling element (19) is thermally coupled to the winding (7) of the at least one coil (5) by at least one electrically insulating thermally conductive structure (20).

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