CN114450763A

CN114450763A - Common mode choke coil

Info

Publication number: CN114450763A
Application number: CN202080070880.3A
Authority: CN
Inventors: S·恩格勒; G·A·拉塞克; A·库丘克; H·梅尔兹; M·拉夫; F·布里尔曼; D·伯格; M·哈格尔; W·金勒; K·斯帕诺斯
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2019-10-10
Filing date: 2020-09-30
Publication date: 2022-05-06
Also published as: DE102019215514A1; WO2021069266A1; EP4042458A1

Abstract

The invention relates to a common mode choke (1). The common mode choke (1) has a ring core (2) which is permeable in particular to magnetic flux and a coil. The common mode choke has at least one further coil, wherein the coil and the further coil are each arranged in the region of the toroidal core (2) in such a way that a magnetic flux passing through the coil detects the toroidal core (2). According to the invention, the annular core (2) surrounds a preferably cylindrical through-hole (4). The coil comprises at least one or only one electrical inner conductor (31-34), in particular a busbar, for each coil turn, wherein the inner conductors (31-34) are arranged in the perforations (4). The inner conductors (31-34) arranged in the through-holes (4) together form the shape, in particular the cross-sectional shape, of the corresponding through-hole (4) and thus together fill the through-hole (4).

Description

Common mode choke coil

Technical Field

The present invention relates to a common mode choke coil. The common mode choke has a ring core and a coil which are permeable in particular to magnetism. The common-mode choke has at least one further coil, wherein the coil and the further coil are each arranged in the region of the toroidal core in such a way that the magnetic flux passing through the coil can detect the toroidal core.

Background

Common mode chokes are used for EMV immunity (EMV = electromagnetic compatibility). For this purpose, the common-mode choke has at least two or only two coils, which can magnetically interact with one another via a toroidal core. The coil currents in the two coils are preferably conducted in different directions from each other, so that the EMV disturbances in the toroidal core magnetically cancel each other out.

Disclosure of Invention

According to the invention, the annular core comprises a preferably cylindrical through-hole. The coil has at least one or only one electrical inner conductor, in particular a busbar, for each coil turn, wherein the inner conductor is arranged in the perforation. The inner conductors arranged in the perforations together form the shape, preferably the cross-sectional shape, of the corresponding perforations and thus together fill the perforations.

The common-mode choke can thus advantageously be constructed particularly space-saving. It is understood that, when the cross section of the through hole can be fully energized by the inner conductor, the impedance of the common mode choke coil can be effectively increased.

In a preferred embodiment, the inner conductors each have a circle segment-shaped cross section. In particular cylindrical bores, can thus advantageously be completely filled with the inner conductor. In a preferred embodiment, the coils each have only one coil turn, the inner conductors for this purpose each being semicircular in cross section.

In another embodiment, the coils each have two coil turns. The inner conductors are preferably each formed in cross section in the shape of a quarter circle segment. The perforation can thus be advantageously filled with two coil turn sections each. Each inner conductor forms a turn section of a coil turn. The inductance can advantageously be raised quadratically in two or more coil turns.

In a preferred embodiment, the common mode choke coil has a holding body of electrically insulating construction. The holding body at least partially surrounds the annular core and has a hollow cylinder formed to the holding body, wherein a cavity of the hollow cylinder forms a through-hole for receiving the inner conductor. The toroidal core can thus advantageously be electrically insulated from the inner conductor. The inner conductor can therefore advantageously be embodied as a solid, in particular non-insulated metal part, in particular a copper part.

The inner conductors are preferably each designed as a particularly straight rod. The inner conductor can therefore be provided at low cost, for example as an extruded or rolled profile.

In a preferred embodiment, the inner conductors are each connected with a terminal, in particular an end side, to a busbar, which is led away from the terminal of the inner conductor, in particular at right angles. The busbars are formed, for example, by a stamped grid, also referred to as a lead frame (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 conductor can therefore advantageously be connected with its end face to the busbar material and in an electrically conductive manner, for example soldered or welded. The busbar can be formed, for example, bent away from the end, in particular the end face, of the inner conductor, at least partially surrounding the annular core. The curved busbar can thus advantageously form an outer conductor, wherein the curved section runs parallel to the inner conductor.

The common-mode choke can thus advantageously be reflowed with the end side of the inner conductor to the circuit carrier. The bus bar, which can be connected to the end of the inner conductor opposite thereto in an electrically conductive, in particular materially bonded manner, can be soldered to the circuit carrier with the end facing away therefrom. The bus bar and the inner conductor preferably each have an end which is in a plane, in particular in the plane of the circuit carrier.

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 a, in particular ceramic, circuit carrier having at least one outer electrically conductive layer and at least one electrically insulating layer, in particular a ceramic layer.

The circuit carrier is preferably a ceramic circuit carrier, in which the electrically insulating layer is formed from a ceramic layer. The layer capable of conducting electricity is preferably a copper layer or an aluminum layer. The circuit carrier is preferably an IMS circuit carrier (IMS = insulated metal substrate), a DCB circuit carrier (DCB = direct copper bonding), an AMB circuit carrier (AMB = active metal soldering), an LTCC circuit carrier (LTCC = low temperature co-fired ceramic) or an HTCC circuit carrier (high temperature co-fired ceramic).

The electrically conductive layer forms a bus bar that is connected to an end of one of the inner conductors. The circuit carrier can thus advantageously form a busbar which forms a part of the coil turns, wherein said part is connected to the inner conductor. The bus bar may further preferably form a connecting element which electrically connects two coil turns of the same coil to each other. A coil comprising two turns may thus comprise, for example, two inner conductors arranged next to one another, which are each arranged in a bore. The inner conductors each form part of a coil turn of the same coil, wherein the coil turns are each coupled to an end face of the inner conductor and are each guided around the toroidal core at right angles. The part of the coil turns which is guided around the annular core is formed, for example, by a busbar, in particular a stamped grid, which forms the outer conductor. The coil turns of the same coil are connected to each other so as to be electrically connected in series, which may be formed by means of a busbar of a circuit carrier, which contacts the inner conductor.

The coil turns may thus comprise an inner conductor, a curved outer conductor and a conductive layer of a circuit carrier, for example an IMS substrate. The inner conductor and the outer conductor are preferably connected to the substrate, in particular the IMS substrate, by means of solder material bonding.

In a preferred embodiment of the contact system, the end of the inner conductor facing away from the circuit carrier is connected to a busbar, which preferably forms the outer conductor, and which is guided by the facing end outwardly around the annular core and is connected to the circuit carrier. The bus bars are preferably formed from a stamped grid or lead frame. The part of the coil turns formed by the busbar, in particular the stamped grid, can advantageously be provided by a preformed sheet metal part, in particular a copper sheet metal part, which is placed over the end of the inner conductor facing away from the circuit carrier and can be welded or spot-welded there to the inner conductor. It may thus be advantageously advantageous to provide the choke coil cost-effectively.

In a preferred embodiment of the contact system, the circuit carrier is connected to the heat sink in a thermally conductive manner at least in the region of the inner conductor and/or of the annular core. It is further preferred that the choke coil is clamped, in particular in a sandwich-like manner, between two, in particular ceramic-like, circuit carriers. The contact arrangement thus formed can advantageously be connected to a heat sink from both sides of the circuit carrier, in particular from the side of the circuit carrier directed outwards.

The heat dissipation device, which can be connected to the circuit carrier, for example, by means of a thermally conductive, in particular electrically insulating material, also referred to as TIM (TIM = thermal insulation material), can in particular effectively dissipate the heat loss generated in the common-mode choke. It is of course also possible to effectively dissipate the heat loss to the end face of the inner conductor. It is further known that a ring core in the aforementioned contact arrangement of the contact system can facilitate a cost-effective and efficient heat dissipation by means of the circuit carrier.

In a preferred embodiment of the common mode choke, electrically insulating separating webs or spacers are arranged between the inner conductors of the coils that differ from one another. The separating webs are, for example, ceramic webs, glass webs or plastic webs. The separating web is preferably formed on the retaining body. The retaining body can in this way be advantageously formed integrally with the separating web as an injection-molded part. The separating webs are formed, for example, in a T-shaped or double-T-shaped cross section, the legs of the T each being arranged to at least partially surround a corner of the inner conductor. The corners of the inner conductor are thus advantageously protected against high voltage flashovers or spark discharges.

The invention will now be explained in the following with the aid of figures and further embodiments. Further advantageous embodiments result from the combination of the features specified in the dependent claims and the drawings.

Drawings

Fig. 1 shows an exemplary embodiment of a contact arrangement with a common-mode choke in a sectional view, which is clamped between two circuit carriers and connected to these circuit carriers;

fig. 2 shows the common-mode choke shown in fig. 1 in a cross-sectional view;

fig. 3 shows an embodiment of a common mode choke with two coil turns for each coil of the common mode choke;

fig. 4 shows an embodiment of a common mode choke with three coil turns for each coil of the common mode choke;

fig. 5 shows an embodiment of a common mode choke with a rectangularly shaped annular core.

Detailed Description

Fig. 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 ring core 2, which in this exemplary embodiment is in the form of a hollow cylinder, which in this exemplary embodiment is embedded in a plastic sleeve 3.

The common mode choke coil 1 also has a cylindrical through hole 4. The plastic sleeve 3 comprises an outer jacket 28 which surrounds the annular core 2 and in this embodiment also extends at the inner wall of the annular core 2, so that the plastic sleeve forms a hollow cylinder 29 at the inner side of the annular core 2, in the cavity of which the coils of the common mode choke, in particular the inner conductor, can be arranged and thus also in the perforation 4.

At least two or an integer multiple of two inner conductors, in the present exemplary embodiment only two inner conductors, namely inner conductor 6 and inner conductor 7, are arranged in perforation 4. The inner conductor 6 forms in this embodiment part of the first coil of the common mode choke. The inner conductor 7 forms in this embodiment part of the second coil of the common mode choke. The coils of the common mode choke each have only one partial turn in this exemplary embodiment. The partial turns extend in the perforations in this embodiment and extend from the, in particular centrally arranged, perforation of the annular core 2. In contrast to a full wire turn which once surrounds the annular core, a partial wire turn extends only toward the inner conductor and is led away again from this inner conductor after passing through the perforation.

The contact arrangement 10 in this exemplary embodiment also comprises two circuit carriers 8 and 9, in particular of ceramic design. The common mode choke 1, in particular the toroidal core 2, and the at least two

inner conductors

6 and 7 are in this embodiment sandwiched between circuit carriers 8 and 9.

The circuit carriers 8 and 9 comprise an electrically insulating layer 14 and two electrically

conductive layers

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

The

inner conductors

6 and 7 each have two end faces, which are each connected in a bonded manner, in particular soldered, to the electrically conductive layer material of one of the circuit carriers.

For this purpose, the inner conductor 7 has an end face 23, which is connected to the electrically conductive layer 12. The end of the inner conductor 7 opposite thereto is formed by an end side 24, which is connected to the electrically conductive layer 15 of the circuit carrier 8 by means of a material bond. The conductive layers 12 and 15, which form the busbars, respectively, form, together with the inner conductor 7, a U-shape which surrounds the ring core 2. The inner conductors 12 and 15 thus form, together with the inner conductor 7, a coil from which the electromagnetically active part in the form of the inner conductor 7 extends in the perforation 4.

The inner conductor 6 has

end sides

25 and 26, which are each formed by the ends of the inner conductor 6 facing away from one another. The end side 25 is connected to the electrically conductive layer 13 in a bonded manner, and the end side 26 formed at the other end of the inner conductor is connected to the electrically conductive layer 16 in a bonded manner. The electrically

conductive layers

13 and 16 thus form, together with the inner conductor 6, a U-shape which surrounds the annular core 2 over the circumferential section lying opposite the inner conductor 7. The circuit carrier 8, in particular the ceramic layer 14 of electrically insulating construction, is connected in this embodiment in a thermally conductive manner to a heat sink 17. The heat sink 17 has in this embodiment fluid channels for guiding a cooling fluid, for example one of the fluid channels 18 is indicated. The heat losses 27 generated when the

inner conductor

6 or 7 is energized can be conducted from the

inner conductor

6 or 7 via the electrically

conductive layer

16 or 15 and further via the electrically insulating layer 14, in particular a ceramic layer, to the heat sink 17. The heat sink 17 is formed of, for example, an aluminum block.

In contrast to the illustration in fig. 1, the two circuit carriers 8 and 9, which sandwich the common-mode choke 1, can each be connected to a heat sink.

The coils of the common mode choke 1 are electrically insulated from one another in this embodiment by insulating webs 5, which are also referred to as separating webs before. The common-mode choke can thus safely be separated by a potential of a few hundred volts or between 500 and 1000 volts, which potential drops on the coil comprising the

inner conductors

6 and 7.

In contrast to the illustration in fig. 1, the contact arrangement 10 can have only one circuit carrier, for example the circuit carrier 8. The end sides 23 and 25 of the

inner conductors

6 and 7 facing away from the circuit carrier 8 can each be connected to a stamped grid or lead frame, which is guided from the inner conductors around the ring core 2 and to the circuit carrier 8 and is connected there to the circuit carrier 8. The common-mode choke formed in this way can, for example, be connected to a heat sink and dissipate the heat loss to the heat sink via the circuit carrier 8. The outer conductor may thus be formed by stamping the grid or the lead frame, which outer conductor is connected to the inner conductor and thus forms part of the full turns of the coil.

Fig. 2 shows the choke 1 shown in fig. 1 in a sectional view, wherein the basic section extends transversely to the longitudinal extent of the perforations 4.

The toroidal core 2 is at least partially or completely surrounded by a plastic jacket 3. The plastic jacket 3 comprises in this embodiment an outer jacket 28 which surrounds the lateral surface of the ring core 2, which in this embodiment is cylindrically shaped, and an inner cylinder 29 which extends in a bore formed in the ring core 2 and covers the inner wall of the ring core.

The inner cylinder 29, which is of electrically insulating construction, is configured as a hollow cylinder and surrounds the perforation 4. The

inner conductors

6 and 7, which have been shown in fig. 1, are arranged in the perforation 4 and extend parallel to one another and along the longitudinal axis 30, which has been shown in fig. 1. The

inner conductors

6 and 7 of the common mode choke 1 form respective turns of the coil or, in combination with the circuit carriers 8 and 9, form part of the turns, wherein the remaining part of the turns is formed by the electrically conductive layer of the circuit carrier.

The

inner conductors

6 and 7 are in this exemplary embodiment designed in the shape of circle segments, in particular in the shape of a semicircle. The perforation 4 can thus be almost completely or completely filled with the

inner conductors

6 and 7, except for the partition 5. The bore 4 is divided by the partition into two

partial spaces

21 and 22 in which coils different from one another or coil parts of coils different from one another are arranged in each case. The

subspaces

21 and 22 thus represent mutually different coils of the common mode choke 1.

Fig. 2 also shows a separating plane 20 which divides the perforation 4 into two

subspaces

20 and 21 which are in particular equally large. The

subspaces

20 and 21 are each separated from one another by a partition 5, so that the

inner conductors

6 and 7, which are each arranged in one of the

subspaces

20 or 21, are electrically insulated from one another in a puncture-proof manner.

Fig. 3 shows an embodiment of the common mode choke 19. The common-mode choke 19 has in this embodiment a perforation 4 which is divided into two

subspaces

21 and 22 by a partition 39, also referred to as a partition web before. In each of the

partial spaces

21 and 22, in each case parts of a coil, in particular turns, are arranged, so that the coil parts accommodated in each case in one partial space are electrically insulated from the coil parts in the partial space opposite the partition 39.

The coils of the common mode choke 19 each have two turns in this embodiment. Each turn comprises in this embodiment an inner conductor which extends in the subspace of the perforation 4.

In this embodiment, an inner conductor 31 and an inner conductor 32 are arranged in the subspace 21, which inner conductors each form part of a coil turn for the coil of the common mode choke 19. In the subspace 22, two

inner conductors

33 and 34 are arranged, which each form part of a further coil. The remaining part of the coil turns, which electrically connects the inner conductors in series with one another in such a way that the coil currents in the inner conductors of the same coil flow in the same direction in the through-holes, can be formed by an electrically conductive layer, for example a stamped grid, of the circuit carrier and of the electrical outer conductor.

In this exemplary embodiment, the

inner conductors

31, 32, 33 and 34 are each formed in cross section in the shape of a circle segment, in particular a quarter circle segment. The two inner conductors, which are each formed in the shape of a quarter circle segment in cross section, can in this way together fill the half-cylinder subspace almost completely or completely.

In the coil shown in fig. 3, two inner conductors may be connected in parallel with each other in order to form a coil with only one turn. The coil then has at least one, in particular two, inner conductors for each coil turn.

Fig. 4 shows an embodiment of the common mode choke 35. The common mode choke 35 comprises a ring core 2 in which a bore 4 is formed. In the bore 4, an electrically insulating partition 36 is formed, which divides the cylindrical bore 4 into two, in particular semi-cylindrical,

subspaces

20 and 21.

In each of the subspaces, parts of the coil turns of the same choke coil are accommodated. In the exemplary embodiment according to fig. 4, each coil turn of the common mode choke 35 comprises three coil turns, wherein each coil turn comprises an inner conductor as part of the coil turn. The three inner conductors of the coil, which are arranged in the partial spaces 21, are each formed in cross section in the form of a circular segment, wherein the circular segments together form a semicircle along the radial circumferential structure. The inner conductors (for example one of these inner conductors 37 is indicated) thus together form the shape of a half cylinder arranged side by side in the subspace 21.

Opposite the partition 36, a subspace 22 is arranged opposite the subspace 21, in which the three inner conductors of the further coil are arranged. The further coil thus comprises three coil turns, wherein each coil turn has one of the three inner conductors. One of the inner conductors 38 of the further coils is exemplarily marked.

The perforations 4 are thus completely filled by the inner conductors of the coil and of the further coil and by the spacers separating the coils. The inner conductor of each coil thus forms a half cylinder for this purpose, and the inner conductors of the two coils, in particular of the coil and the further coil, together form a full cylinder.

In the coil shown in fig. 4, three inner conductors may be connected in parallel with each other in order to form a coil with only one turn. The coil then has at least one, in particular three, inner conductors for each coil turn.

Fig. 5 shows an embodiment of the choke coil 40. The choke coil 40 is different from the choke coil shown in fig. 2, 3 and 4 in having a rectangular shaped annular core 41. The annular core 41 surrounds the perforations 42 in this embodiment. Four inner conductors are arranged in the through-hole 42, wherein two inner conductors arranged next to each other form parts of the coil of the common mode choke.

The first coil here comprises

inner conductors

43 and 44. The further coil comprises

inner conductors

45 and 46. The

inner conductors

43 and 44 are separated from the

inner conductors

45 and 46 of the other coils by electrically insulating spacers 47. The partition 47 is in this case a component of a plastic body into which the annular core 41 is at least partially or completely embedded.

In this embodiment, the

inner conductors

43, 44, 45 and 46 each have a rectangular or square cross section. The annular core with the rectangular or square through-hole can thus advantageously be completely filled by the inner conductor and thus make the best possible use of space. The common-mode choke can therefore be implemented in a small installation space with a large inductance.

Claims

1. Common mode choke (1, 19, 35, 40) having a particularly magnetically permeable toroidal core (2) and at least one coil (6, 31, 32, 37) and a further coil (7, 31, 32, 38), wherein the coil (6, 31, 32, 37) and the further coil (7, 31, 32, 38) are each arranged in the region of the toroidal core (2) in such a way that a magnetic flux passing through the coil (6, 31, 32, 37, 7, 31, 32, 38) detects the toroidal core (2),

characterized in that the annular core (2) surrounds a bore (4), in particular cylindrical, and the coils (6, 31, 32, 37, 7, 31, 32, 38) each comprise at least one electrical inner conductor (6, 31, 32, 37, 7, 31, 32, 38), in particular a busbar, for each coil turn, which inner conductors are arranged in the bore (4), wherein the inner conductors arranged in the bore (4), in particular in cross section, together form the shape of the corresponding bore (4) and thus jointly fill the bore (4).

2. A common mode choke (1, 19, 35) according to claim 1, characterized in that the inner conductors (6, 31, 32, 37, 7, 31, 32, 38) each have a circular segment-shaped cross section.

3. A common-mode choke (1, 19, 35) according to claim 1 or 2, characterized in that the coils (21, 22) each have coil turns and the inner conductors (6, 7) are each configured in a semicircular shape in cross section for this purpose.

4. A common-mode choke (1, 19, 35) according to claim 1 or 2, characterized in that the coils (21, 22) each have two coil turns, wherein the inner conductors (31, 32, 33, 34) are each formed in the shape of a quarter-circle segment in cross section for this purpose.

5. A common-mode choke (1, 19, 35) according to any one of the preceding claims, characterized in that the common-mode choke (1, 19, 35) has a holding body (3) of electrically insulating construction which at least partially surrounds the annular core (2) and has a hollow cylinder (29) formed to the holding body (3), wherein the hollow space of the hollow cylinder (29) forms the through-hole (4) for accommodating the inner conductor.

6. A common-mode choke (1, 19, 35) according to any one of the preceding claims, characterized in that the inner conductors are connected with ends with busbars, respectively, which run out of the ends of the inner conductors, in particular at right angles.

7. 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 a, in particular ceramic, circuit carrier (8, 9) having at least one outer, electrically conductive layer (12, 13, 15, 16) and at least one electrically insulating layer (11, 14), wherein the electrically conductive layer (12, 13, 15, 16) has a busbar which is connected, in particular at the end side, to an end (23, 24, 25, 26) of one of the inner conductors (6, 31, 32, 37, 7, 31, 32, 38).

8. Contact arrangement (10) according to claim 7, characterized in that the ends of the inner conductors (23, 25) facing away from the circuit carrier are connected to busbars which are formed guided by the facing ends (23, 25) around the annular core (2) and are connected to the circuit carrier (8).

9. Contact arrangement (10) according to claim 7 or 8, characterized in that the circuit carrier (8, 9) is thermally conductively connected to a heat sink (17) at least in the region of the inner conductor (6, 31, 32, 37, 7, 31, 32, 38) and/or of the ring core (2).

10. Contact arrangement (10) according to any one of the preceding claims, characterized in that electrically insulating separating webs (5, 39, 47) are arranged between the inner conductors (6, 31, 32, 37, 7, 31, 32, 38) of the mutually different coils (21, 22).