DE102019215514A1 - Common mode choke - Google Patents

Abstract

The invention relates to a common mode choke. The common mode choke has an in particular magnetically permeable toroidal core and a coil. The common-mode choke has at least one further coil, the coil and the further coil each being arranged in the area of the toroidal core in such a way that a magnetic flux penetrating the coils can detect the toroidal core. According to the invention, the toroidal core encloses a preferably cylindrical through-hole. For each coil turn, the coils each have at least one or only one electrical inner conductor, in particular a busbar, the inner conductor being arranged in the opening. The inner conductors arranged in the opening together form a shape corresponding to the opening, preferably a cross-sectional shape, and thus jointly fill the opening.

Description

State of the art

The invention relates to a common mode choke. The common mode choke has an in particular magnetically permeable toroidal core and a coil. The common-mode choke has at least one further coil, the coil and the further coil each being arranged in the area of the toroidal core in such a way that a magnetic flux penetrating the coils can detect the toroidal core.

Common mode chokes are used for EMC suppression (EMC = electro-magnetic compatibility). For this purpose, common-mode chokes have at least two or only two coils, which can interact magnetically with one another via a toroidal core. The coil current in the two coils is preferably conducted in mutually different directions, so that EMC interference in the toroidal core magnetically cancel each other out.

Disclosure of the invention

According to the invention, the toroidal core encloses a preferably cylindrical through-hole. For each coil turn, the coils each have at least one or only one electrical inner conductor, in particular a busbar, the inner conductor being arranged in the opening. The inner conductors arranged in the opening together form a shape corresponding to the opening, preferably a cross-sectional shape, and thus jointly fill the opening.

The common-mode choke can thus advantageously be designed to be particularly space-saving. This is because it was recognized that the impedance of a common mode choke can be effectively increased if the cross-sectional area of the opening can be fully energized by the inner conductors.

In a preferred embodiment, the inner conductors each have a cross-section in the shape of a segment of a circle. Advantageously, the particularly cylindrical opening can thus be completely filled by the inner conductor.
In a preferred embodiment, the coils each have only one coil turn, the inner conductors each being semicircular in cross section for this purpose.

In another embodiment, the coils each have two coil turns. For this purpose, the inner conductors are preferably each embodied in the form of a quarter segment in cross section. The breakthrough can thus advantageously be filled in to fill space by two coil winding sections in each case. Each inner conductor forms a turn section of a coil turn. The inductance can advantageously be increased quadratically with two or more coil turns.

In a preferred embodiment, the common mode choke has an electrically insulating holding body. The holding body at least partially encloses the toroidal core and has a hollow cylinder molded onto the holding body, a cavity of the hollow cylinder forming the opening for receiving the inner conductor. The toroidal core can thus advantageously be electrically isolated from the inner conductors. The inner conductors can thus advantageously be designed as solid, in particular uninsulated, metal pieces, in particular copper pieces.

The inner conductors are preferably each designed as a straight rod, in particular. As a result, the inner conductors can be provided at low cost, for example as an extruded profile or a rolled profile.

In a preferred embodiment, the inner conductors are each connected at one end, in particular one end face, to a busbar, which is led away from the ends of the inner conductor, in particular at right angles. The busbar is formed, for example, by a stamped grid, also called a leadframe, or by a circuit carrier, in particular a ceramic circuit carrier. The common-mode choke can thus advantageously be provided in a space-saving manner. The inner conductors can thus advantageously be connected with one end face to the busbar in a materially and electrically conductive manner, for example soldered or welded. The busbar can, for example, be formed at an angle leading away from one end, in particular an end face of the inner conductor, at least partially enclosing the toroidal core.
The angled busbar can thus advantageously form an outer conductor, with an angled section extending parallel to the inner conductor.

The common-mode choke can thus advantageously be reflow-soldered to an end face of the inner conductor with a circuit carrier. The busbar, which is electrically conductive, in particular cohesively connected to an opposite end of the inner conductor, can be soldered to the circuit carrier with an end facing away therefrom. The busbar and the inner conductor preferably each have an end which lies in one plane, in particular the circuit carrier plane.

The invention also relates to a contact system. The contact system has a common mode choke of the type described above. The contact system preferably comprises one in particular ceramic circuit carrier, which has at least one outer electrically conductive layer and at least one electrically insulating layer, in particular ceramic layer.

The circuit carrier is preferably a ceramic circuit carrier in which the electrically insulating layer is formed by a ceramic layer. The electrically conductive layer is preferably a copper layer or an aluminum layer. The circuit carrier is preferably an IMS circuit carrier (IMS = Insulated Metal Substrate), DCB circuit carrier (DCB = Direct Copper Bonded), AMB circuit carrier (AMB = Active Metal Brazed), LTCC circuit carrier (LTCC = Low-Temperature-Cofired-Ceramics) or an HTCC circuit carrier (HTCC = High-Temperature-Cofired-Ceramics).

The electrically conductive layer forms a busbar that is connected to one end of one of the inner conductors. The circuit carrier can thus advantageously form a busbar which forms part of a coil winding, the part being connected to the inner conductor. The busbar can further preferably form a connecting element which electrically connects two coil windings of the same coil to one another. Thus, a coil comprising two turns, for example two inner conductors arranged adjacent to one another, which are each arranged in the opening. The inner conductors each form part of a coil winding of the same coil, the coil windings each coupling to the end faces of the inner conductor being guided around the toroidal core at right angles. The parts of the coil winding that are guided around the toroidal core are formed, for example, by a busbar, in particular a stamped grid, which forms an outer conductor. The connection of the coil windings of the same coil to one another to form a serial electrical connection of the same can be formed by means of the conductor rail of the circuit carrier, which contacts an inner conductor.

A coil turn can thus comprise an inner conductor, the angled outer conductor and an electrically conductive layer of a circuit carrier, for example an IMS substrate. The inner conductor and the outer conductor are preferably materially connected to a substrate, in particular an IMS substrate, by means of a solder.

In a preferred embodiment of the contact system, one end of the inner conductor facing away from the circuit carrier is connected to a busbar, which preferably forms an outer conductor, which is shaped from the rejecting end to lead around the toroidal core and is connected to the circuit carrier. The busbar is preferably formed by a stamped grid or leadframe. A part of the coil winding, which is formed by the busbar, in particular the lead frame, can advantageously be provided by a preformed sheet metal part, in particular a sheet copper part, which is placed on an end of the inner conductor facing away from the circuit carrier, and there is soldered or spot-welded to the inner conductor can be. The choke coil can thus advantageously be provided at low cost.

In a preferred embodiment of the contact system, the circuit carrier is connected in a thermally conductive manner to a heat sink at least in the area of the inner conductor and / or the toroidal core. The choke coil is furthermore preferably enclosed between two circuit carriers, in particular of ceramic design, in particular in the manner of a sandwich. The contact arrangement formed in this way can advantageously be connected to a heat sink from both sides of the circuit carrier, in particular from outwardly facing sides of the circuit carrier.

The heat sink, which can be connected to the circuit carrier, for example by means of a particularly electrically insulating heat-conducting material, also called TIM (TIM = Thermal Insulation Material), can dissipate the heat loss generated in the common-mode choke particularly efficiently. This is because it was recognized that heat loss can be efficiently dissipated to the end faces of the inner conductor. It was also recognized that the toroidal core in the above-described contact arrangement of the contact system can be cooled efficiently and inexpensively via the circuit carrier.

In a preferred embodiment of the common mode choke, an electrically insulating separating web or a separating wall is arranged between inner conductors that are different from one another. The separating web is, for example, a ceramic web, glass web or plastic web. The separating web is preferably molded onto the holding body. In this way, the holding body can advantageously be designed in one piece together with the separating web as a plastic injection-molded part. The separating web is formed, for example, with a T-shaped or double-T-shaped cross-section, the T-legs each being arranged to at least partially encompass a corner of an inner conductor. The corners of the inner conductors are thus advantageously protected against high-voltage breakdowns or arcing.

• 1 zeigt ein Ausführungsbeispiel für eine Kontaktanordnung mit einer Gleichtaktdrossel in einer Schnittdarstellung, die zwischen zwei Schaltungsträgern eingeschlossen und mit diesen verbunden ist;
• 2 zeigt die in 1 dargestellte Gleichtaktdrossel in einer Querschittdarstellung;
• 3 zeigt eine Ausführungsform für eine Gleichtaktdrossel mit zwei Spulenwindungen für jede Spule der Gleichtaktdrossel;
• 4 zeigt ein Ausführungsbeispiel für eine Gleichtaktdrossel mit drei zwei Spulenwindungen für jede Spule der Gleichtaktdrossel;
• 5 zeigt ein Ausführungsbeispiel für eine Gleichtaktdrossel mit einem rechteckig geformten Ringkern;

The invention will now be described below with reference to figures and further exemplary embodiments. Further advantageous design variants result from a combination of the features described in the dependent claims and in the figures.

• 1 shows an exemplary embodiment of a contact arrangement with a common mode choke in a sectional illustration, which is enclosed between two circuit carriers and connected to them;
• 2 shows the in 1 Common mode choke shown in a cross-sectional view;
• 3 shows an embodiment for a common mode choke with two coil turns for each coil of the common mode choke;
• 4th shows an embodiment for a common mode choke with three two coil turns for each coil of the common mode choke;
• 5 shows an embodiment for a common mode choke with a rectangular shaped toroidal core;

1 shows an embodiment of a contact arrangement 10 . The contact arrangement 10 has a common mode choke 1 , which is partially shown in a sectional view. The common mode choke 1 has a toroidal core in the form of a hollow cylinder in this exemplary embodiment 2 on, which in this embodiment is in a plastic jacket 3 is embedded.

The common mode choke 1 also has a cylindrical opening 4th on. The plastic jacket 3 includes the toroidal core 2 enclosing outer shell 28 and in this exemplary embodiment also extends on an inner wall of the toroidal core 2 so that the plastic jacket is on the inside of the toroidal core 2 a hollow cylinder 29 forms, in its cavity - and so also in the breakthrough 4th - The coils, in particular the inner conductor of the common mode choke, can be arranged.

In the breakthrough 4th are at least two or an integral multiple of two, in this embodiment only two inner conductors, namely one inner conductor 6th and an inner conductor 7th , arranged. The inner conductor 6th forms part of a first coil of the common mode choke in this exemplary embodiment. The inner conductor 7th forms part of a second coil of the common mode choke in this exemplary embodiment. In this exemplary embodiment, the coils of the common-mode choke each have only one partial turn. In this exemplary embodiment, the partial turn extends into the opening and from the, in particular, centrally arranged opening of the toroidal core 2 .
In contrast to a full turn, which surrounds the toroidal core once, the partial turn only runs towards the inner conductor and leads away from it again after passing through the opening.

The contact arrangement 10 In this exemplary embodiment, it also includes two circuit carriers, in particular of ceramic design 8th and 9 . The common mode choke 1 , especially the toroid 2 and the at least two inner conductors 6th and 7th , are in this embodiment between the circuit carriers 8th and 9 - in particular in the manner of a sandwich - included.

• - insbesondere in einer Ebene angeordnete - elektrisch leitfähige Schichten 15 und 16, welche jeweils eine Stromschiene bilden. Der Schaltungsträger 9 umfasst eine elektrisch isolierende Schicht 11 und zwei elektrisch leitfähige Schichten 12 und 13.

The circuit carrier 8th comprises an electrically insulating layer 14th and two

• - in particular arranged in one plane - electrically conductive layers 15th and 16 , which each form a busbar. The circuit carrier 9 comprises an electrically insulating layer 11 and two electrically conductive layers 12th and 13th .

The inner ladder 6th and 7th each have two end faces which are each materially connected, in particular soldered, to an electrically conductive layer of one of the circuit carriers.

The inner conductor 7th has an end face for this purpose 23 on which with the electrically conductive layer 12th connected is. An opposite end of the inner conductor 7th is through an end face 24 formed which with the electrically conductive layer 15th of the circuit carrier 8th is firmly connected. The electrically conductive layers 12th and 15th , which each form a busbar, form together with the inner conductor 7th a U-shape, which is the toroidal core 2 encloses. The inner ladder 12th and 15th so form together with the inner conductor 7th a coil, from which an electromagnetically effective part is in the form of the inner conductor 7th in the breakthrough 4th extends.

The inner conductor 6th has an end face 25th and an end face 26th on, which each by mutually facing ends of the inner conductor 6th are formed. The front side 25th is with the electrically conductive layer 13th cohesively connected, and the end face formed at the other end of the inner conductor 26th is with the electrically conductive layer 16 firmly connected. The electrically conductive layers 13th and 16 so form together with the inner conductor 6th a U-shape, which is the toroidal core 2 on one to the inner conductor 7th opposite circumferential section encloses. The circuit carrier 8th , in particular the electrically insulating ceramic layer 14th , is in this embodiment with a heat sink 17th thermally conductively connected. The heat sink 17th in this exemplary embodiment has fluid channels for guiding a cooling fluid, one of which is a cooling channel 18th is designated by way of example. Heat loss 27 , which when energizing the inner conductor 6th or the inner conductor 7th can be generated by the inner conductors 6th respectively 7th via the electrically conductive layers 16 respectively 15th , and further over the electrically insulating layer 14th , in particular ceramic layer, to the Heat sink 17th be directed. The heat sink 17th is formed for example by an aluminum block.

Unlike in 1 shown, both circuit carriers 8th and 9 , which is the common mode choke 1 include between each other, each be connected to a heat sink.

The coils of the common mode choke 1 are in this embodiment by an isolation bar 5 , previously also called separator, electrically isolated from one another. The common mode choke can have a potential of several hundred volts, or between 500 and 1000 volts, which is above the coils, including the inner conductors 6th and 7th , falls off, safely disconnect.

Unlike in 1 shown, the contact arrangement 10 only one circuit carrier, for example the circuit carrier 8th exhibit. The one from the circuit carrier 8th repellent end faces 23 and 25th the inner conductor 6th respectively 7th can each be connected to a lead frame or leadframe that extends from the inner conductor to the toroidal core 2 around and up to the circuit board 8th out and there with the circuit carrier 8th connected is. The common mode choke formed in this way can be connected, for example, to a heat sink and via the circuit carrier 8th Dissipate heat loss to the heat sink. For example, the lead frame or leadframe can form an outer conductor that connects to the inner conductor and thus forms part of a full turn of the coil.

2 shows the in 1 shown throttle 1 in a sectional view, the underlying section extending transversely to a longitudinal extension of the opening 4th extends.

The toroid 2 is from the plastic jacket 3 at least partially or completely enclosed. The plastic jacket 3 comprises in this embodiment an outer shell 28 , which is a lateral surface of the toroidal core, which is cylindrically shaped in this exemplary embodiment 2 enclosing, and an inner cylinder 29 which is in one in the toroid 2 formed opening extends, and covers an inner wall of the toroidal core.

The electrically insulating inner cylinder 29 is designed as a hollow cylinder and encloses the opening 4th . In the 1 inner conductor already shown 6th and 7th are in the breakthrough 4th arranged and extend parallel to each other and along an in 1 longitudinal axis already shown 30th . The inner ladder 6th and 7th the common mode choke 1 each form a coil turn, or in connection with the circuit carriers 8th and 9 , a partial turn, the remaining part of the turn being formed by electrically conductive layers of the circuit carrier.

The inner ladder 6th and 7th are in this exemplary embodiment in the shape of a segment of a circle, in particular a semicircle. So can the breakthrough 4th who have favourited the partition 5 except through the inner conductor 6th and 7th almost completely or completely filled out. The breakthrough 4th is divided into two sub-rooms through the partition 21 and 22nd divided, in each of which mutually different coils or coil parts are arranged mutually different coils. The subspaces 21 and 22nd thus represent mutually different coils of the common mode choke 1 .

2 also shows a parting plane 20th which made the breakthrough 4th in two in particular equally large sub-spaces 20th and 21 divides. The subspaces 20th and 21 are each through the partition 5 separated from each other so that the inner conductor 6th and 7th , each in one of the sub-spaces 20th respectively 21 are arranged, are electrically insulated from one another in a breakdown-proof manner.

3 shows an embodiment for a common mode choke 19th . The common mode choke 19th has a breakthrough in this exemplary embodiment 4th on which by a partition 39 , previously also called a divider, into two sub-spaces 21 and 22nd is divided. In each of the sub-rooms 21 and 22nd parts, in particular turns of a coil are arranged in each case, so that the coil parts, which are each accommodated in a subspace, of the coil parts in that of the partition 39 opposite subspace are electrically isolated.

The coils of the common mode choke 19th each have two turns in this exemplary embodiment. In this exemplary embodiment, each turn comprises an inner conductor which is located in a partial space of the opening 4th extends.

In the subspace 21 are in this embodiment an inner conductor 31 and an inner conductor 32 arranged, which each have a part of a coil turn for a coil of the common mode choke 19th form. In the subspace 22nd are two inner conductors 33 and 34 arranged, which each form part of a further coil. The remaining parts of the coil winding can be formed by an electrically conductive layer of a circuit carrier and an electrical outer conductor, for example a punched grid, which electrically connect the inner conductors to one another in series in such a way that a coil current flows in the inner conductors of the same coil in the same direction in the opening.

The inner ladder 31 , 32 , 33 and 34 are in this embodiment in cross section in each case in the form of a segment of a circle, in particular a segment of a circle. In this way, two inner conductors, each formed in the shape of a quarter-circle segment in cross section, can jointly almost completely or completely fill a semicylindrical subspace.

At the in 3 The illustrated coil can be connected in parallel to each other to form a coil with only one turn, two inner conductors. The coil then has at least one, in particular two, inner conductors for each coil turn.

4th shows an embodiment for a common mode choke 35 . The common mode choke 35 includes a toroidal core 2 in which a breakthrough 4th is trained. In the breakthrough 4th is an electrically insulating partition 36 formed, which the cylindrically formed breakthrough 4th in two, in particular, semi-cylindrical sub-spaces 20th and 21 divides.

Parts of a coil turn of the same inductor coil are accommodated in each of the sub-spaces. In the embodiment according to 4th includes each coil turn of the common mode choke 35 three coil turns, each coil turn comprising an inner conductor as part of the coil turn. The three inner conductors of the coil, which are in the subspace 21 are arranged, are each formed in cross section in the shape of a segment of a circle, the segments of a circle together forming a semicircle along a radial circumference. The inner conductor, one of which is an inner conductor 37 is designated by way of example, so form arranged side by side in the subspace 21 a shape of a half cylinder.

To the subspace 21 opposite, beyond the partition 36 , is the subspace 22nd arranged, in which three inner conductors of another coil are arranged. The further coil thus comprises three coil turns, each coil turn having one of the three inner conductors. One of the inner conductors of the further coil is an inner conductor 38 referred to as an example.

The breakthrough 4th is completely filled by the inner conductors of the coil and the further coil, and by the partition separating the coils. The inner conductors of each coil thus form a half cylinder for this purpose, the inner conductors of both coils, in particular the coil and the further coil, together form a full cylinder.

At the in 4th The illustrated coil can be connected in parallel to one another to form a coil with only one turn, three inner conductors. The coil then has at least one, in particular three, inner conductors for each coil turn.

5 shows an embodiment for a choke coil 40 . The choke coil 40 points - different from those in the 2 , 3 and 4th shown choke coils - a rectangular shaped toroidal core 41 on. The toroid 41 encloses a breakthrough in this exemplary embodiment 42 . In the breakthrough 42 four inner conductors are arranged, two inner conductors arranged adjacent to one another forming parts of a coil of the common mode choke.

A first coil encompasses the inner conductor 43 and 44 . Another coil includes the inner conductor 45 and 46 . The inner ladder 43 and 44 are from the inner conductors of the further coil 45 and 46 through an electrically insulating partition 47 Cut. The partition 47 is in this example part of a plastic body in which the toroidal core 41 is at least partially or completely embedded.

The inner ladder 43 , 44 , 45 and 46 each have a rectangular or square cross-section in this exemplary embodiment. The toroidal core, which has a rectangular or square opening, can advantageously be filled completely by the inner conductor and thus with the best possible use of space. The common-mode choke can thus be implemented in a small installation space with a large inductance.

Claims (10)

Common mode choke (1, 19, 35, 40) with an in particular magnetically permeable toroidal core (2) and at least one coil (6, 31, 32, 37) and one further coil (7, 31, 32, 38), the coil ( 6, 31, 32, 37) and the further coil (7, 31, 32, 38) are each arranged in the area of the toroidal core (2) that the coils (6, 31, 32, 37, 7, 31, 32, 38) penetrating magnetic flux detects the toroidal core (2), characterized in that the toroidal core (2) encloses an in particular cylindrical opening (4) and the coils (6, 31, 32, 37, 7, 31, 32, 38 ) for each coil turn each comprise at least one electrical inner conductor (6, 31, 32, 37, 7, 31, 32, 38), in particular a busbar, which is arranged in the opening (4), the in the opening (4) arranged inner conductor, especially in cross section, jointly form a shape corresponding to the opening (4) and thus fill the opening (4) together. Common mode choke (1, 19, 35) Claim 1 , characterized in that the inner conductors (6, 31, 32, 37, 7, 31, 32, 38) each have a circular segment-shaped cross section. Common mode choke (1, 19, 35) Claim 1 or 2 , characterized in that the coils (21, 22) each have one coil turn and the inner conductors (6, 7) for this purpose are each semicircular in cross section. Common mode choke (1, 19, 35) Claim 1 or 2 , characterized in that the coils (21, 22) each have two coil turns, the inner conductors (31, 32, 33, 34) each being designed as a quarter segment in cross section. Common mode choke (1, 19, 35) according to one of the preceding claims, characterized in that the common mode choke (1, 19, 35) has an electrically insulating holding body (3) which at least partially encloses the toroidal core (2) and one at the Holding body (3) has molded hollow cylinder (29), a cavity of the hollow cylinder (29) forming the opening (4) for receiving the inner conductor. Common mode choke (1, 19, 35) according to one of the preceding claims, characterized in that the inner conductors are each connected at one end to a busbar which is led away from the ends of the inner conductor, in particular at right angles. Contact arrangement (10) with a common mode choke (1, 19, 35) according to one of the preceding claims, characterized in that the contact arrangement (10) comprises an in particular ceramic circuit carrier (8, 9) which has at least one outer electrically conductive layer (12, 13, 15, 16) and at least one electrically insulating layer (11, 14), the electrically conductive layer (12, 13, 15, 16) forming a busbar which, at one end (23, 24, 25, 26) , in particular one end face of one of the inner conductors (6, 31, 32, 37, 7, 31, 32, 38) is connected. Contact arrangement (10) according to Claim 7 , characterized in that one end of the inner conductor (23, 25) facing away from the circuit carrier is connected to a busbar which is shaped from the rejecting end (23, 25) to lead around the toroidal core (2) and with the circuit carrier (8 ) connected is. Contact arrangement (10) according to Claim 7 or 8th , characterized in that the circuit carrier (8, 9) is thermally conductive at least in the area of the inner conductor (6, 31, 32, 37, 7, 31, 32, 38) and / or the toroidal core (2) with a heat sink (17) connected is. Contact arrangement (10) according to one of the preceding claims, characterized in that between inner conductors (6, 31, 32, 37, 7, 31, 32, 38) mutually different coils (21, 22) an electrically insulating separating web (5, 39, 47) is arranged.

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