The invention relates to an inductive component that can be used for example as a data line inductor in radio-frequency applications, in particular in applications with high-speed data buses, for example Ethernet buses. Furthermore, the invention relates to a method for producing such an inductive component.
A data line inductor, for which the English designation “common mode choke” is also used as an alternative, comprises a core, for example a ferrite core, on which a first wire and a second wire are wound. The data line inductor serves for transmitting differential signals, wherein the signals flow for example on the first wire as outgoing conductor from the transmitter to the receiver and on the second wire as return conductor from the receiver to the transmitter.
While the data line inductor for the transmission of differential signals is intended to act as conductor via which differential signals are intended to be transmitted with a high data rate and low damping, the transmission of common-mode signals that flow in the same direction in the first and second wires of the data line inductor is intended to be suppressed or damped by the component. For common-mode signals the data line inductor is intended to constitute a high inductance.
Furthermore, the inductive component is intended to generate no or at most a small mode conversion. This is intended to prevent a situation in which a differential-mode data signal is transmitted to the data line inductor and an interference signal is generated therefrom in the inductor. In order to transmit differential-mode signals with low or virtually no damping at all via the inductive component, the component is intended to have a low inductance (leakage inductance) in differential-mode operation for data signals and a high inductance for the transmission of common-mode signals/interference signals. In order to transmit differential-mode signals without damping or with low damping, it is demanded that the leakage inductance of the inductive component is low and the ohmic losses that occur when transmitting data signals via the inductive component are low.
Embodiment provide an inductive component which enables the data transmission of differential signals virtually without damping, but damps interference signals to the greatest possible extent and has a compact design. Furthermore, embodiment provide a method for producing such an inductive component.
In accordance with one embodiment, the inductive component comprises a first and a second wire, a core having a first core part and a second core part, wherein the first core part has a first and second flange section and a wire winding section for winding with the first and second wires, and a multiplicity of contact mounts for contacting a respective end of the first and second wires. The first and second flange sections are arranged at different ends of the wire winding section. The first and second flange sections have a respective first surface, a respective second surface and a respective third surface. The respective first and second surfaces of the first and second flange sections are arranged opposite relative to the respective third surface of the first and second flange sections. The second core part is arranged on the respective third surface of the first and second flange sections. The first and second flange sections have a respective groove that separates the respective first and second surfaces of the first and second flange sections from one another. A first end of the first wire is held at a first of the contact mounts. A second end of the first wire is held at a second of the contact mounts. A first end of the second wire is held at a third of the contact mounts and a second end of the second wire is held at a fourth of the contact mounts. The first and third contact mounts are arranged at the first flange section, while the second and fourth contact mounts are arranged at the second flange section. The first wire proceeding from the first contact mount is led through the groove of the first flange section, wound around the wire winding section and led through the groove of the second flange section to the second contact mount. The second wire proceeding from the third contact mount is led through the groove of the first flange section, wound around the wire winding section and led through the groove of the second flange section to the fourth contact mount.
A method for producing the inductive component is specified in patent claim 9. In accordance with the method for producing an inductive component as specified in patent claim 9, a first and a second wire are provided. Furthermore, a core having a first core part and a second core part is provided, wherein the first core part has a first and second flange section and a wire winding section for winding with the first and second wires. The first and second flange sections are arranged at different ends of the wire winding section, wherein the first and second flange sections have a respective first surface, a respective second surface and a respective third surface. The respective first and second surfaces of the first and second flange sections are arranged opposite relative to the respective third surface of the first and second flange sections. The second core part is arranged on the respective third surface of the first and second flange sections. The first and second flange sections have a respective groove that separates the respective first and second surfaces of the first and second flange sections from one another. Furthermore, the method involves providing a multiplicity of contact mounts comprising a first and second contact mount for contacting a respective end of the first wire and comprising a third and fourth contact mount for contacting a respective end of the second wire. The first and third contact mounts are arranged at the first flange section. The second and fourth contact mounts are arranged at the second flange section. A first end of the first wire is fixed to the first contact mount, and a first end of the second wire is fixed to the third contact mount. The first wire is led through the groove of the first flange section, the wire winding section is wound with the first wire, and the first wire is led through the groove of the second flange section. The second wire is led through the groove of the first flange section, the wire winding section is wound with the second wire, and the second wire is led through the groove of the second flange section. A second end of the first wire is fixed to the second contact mount, and a second end of the second wire is fixed to the fourth contact mount.
The specified production method can be used to provide an inductive component which has a high inductance for the transmission of common-mode signals, for example an inductance of greater than 200 μH, a low inductance for the transmission of signals in differential-mode operation, for example an inductance of less than 0.1% of the common-mode inductance. As a result of the high inductance for common-mode signals, the transmission of interference signals takes place with a high damping. In addition, the first and second wires have a low DC resistance, which for example is less than 6 ohms, as a result of which the damping of data signals is low. The inductive component is furthermore distinguished by a low mode conversion, as a result of which the emission of interference radiation is reduced.
Furthermore, the inductive component has a low leakage inductance and thus guarantees a low insertion loss. For differential data signals, the component has a constant characteristic impedance. The inductance component is suitable in particular for use in radio-frequency applications and in particular in communication networks for transmitting radio-frequency data signals and in high-speed data buses, for example in Ethernet buses.
The first and second wires can be wound in twisted form on the wire winding section of the first core part. The coupling between the adjacent turns and the material of the core can be reduced as a result. A reduction of the magnetic leakage flux can thus be avoided on account of the twisted wire winding. The wires can have a high insulation strength, for example with a degree of insulation starting from 3. The high insulation strength makes it possible to set a characteristic impedance of a wire pair comprising the first and second wires. By selecting a suitable material and a suitable respective diameter of the first and second wires, it is possible to exactly set the characteristic impedance, the thermal behavior and the electrical insulation of the inductive component. By winding the wire winding section with a controlled pitch, it is possible to reduce the coupling capacitance over the winding.
The first and second wires can be wound on the wire winding section in such a way that the position of the first and second wires relative to one another is altered upon each individual complete turn of the first and second wires around the wire winding section. A turn should be understood to mean an individual 360° revolution of a wire around the wire winding section, while a wire winding should be understood to mean all turns of a wire on the wire winding section. On account of the twisting or the transposed arrangement of the first and second wires in adjacent turns, a low leakage inductance can also be achieved besides the reduction of the coupling capacitance between adjacent turns. The two wires can already be twisted before the actual winding of the wire winding section or can be twisted with one another during the winding of the wire winding section.
The first and second core parts can be shaped from a ferrite material. The core has a high permeability, for example of more than 1000. As a result, the core has a low reluctance. Furthermore, with a relatively small number of turns it is possible to achieve high inductance values, for example of more than 200 μH for Ethernet interfaces with low DC voltage resistances, for example of 6 ohms.
The first core part can be embodied with the wire winding section and the first and second flange sections as an I-core. The second core part can be shaped as a plate core that is connected to the two flange sections of the I-shaped first core part. The magnetic circuit can be closed via the flange sections and the plate core. A contact area between the respective flange sections of the first core part and the corresponding contact area of the plate core can be ground, such that a smooth, planar contact area can be formed between the first core part and the second core part. As a result, the inductance component has a high inductance for common-mode signals and at the same time a low DC resistance.
By virtue of the use of specific adhesive materials, the gap width between the plate core and the flange sections of the first core part can turn out to be very small. The ground surface of the two flange sections and the ground surface of the plate core enable the gap between the flange sections and the plate core to be as small as possible. The adhesive layer can be applied directly to a respective surface of the flange sections and/or the respectively opposite surfaces of the plate core. In order to reduce the gap width, an adhesive layer can also be arranged laterally above the gap between the plate core and the two flange sections. On account of the small gap width, the inductive component has a high effective permeability.
The groove provided in each of the flange sections enables a parallel guidance of the first and second wires from the corresponding contact mounts on the first flange section to the wire winding section and from there to the corresponding contact mounts on the second flange section. As a result, the two wires can be wound onto the wire winding section in a manner arranged between the first and second and respectively the third and fourth contact mounts with the same wire length and parallel to one another. The entire wire winding can be embodied symmetrically as a result.
Two contact mounts can be provided at each of the flange sections. Each of the contact mounts serves for fixing a respective end of the first and second wires. The contact mounts can each have a guide element for guiding the wire to a respective contacting element of the contact mounts. The contacting element is designed in particular for fixing the wire ends by laser welding.
The invention is explained in greater detail below with reference to figures showing exemplary embodiments of the present invention. In the figures:
The inductive component comprises a multiplicity of contact mounts 210, 220, 230 and 240 for contacting a respective end of the wires 10 and 20. A first end of the wire 10 is held at a contact mount 210 and a second end of the wire 10 is held at a contact mount 220. A first end of the wire 20 is held at the contact mount 230 and a second end of the wire 20 is held at the contact mount 240. The contact mounts 210 and 230 are arranged at the flange section 111 and the contact mounts 220 and 240 are arranged at the flange section 112. The flange sections 111 and 112 each have a groove 1114 and 1124 for leading through the wires 10 and 20. The wire 10 proceeding from the contact mount 210 can be led through the groove 1114 of the flange section in and be wound around the wire winding section 113 from the side of the flange section 111 in the direction of the flange section 112. The wire 10 can then be led through the groove 1124 of the flange section 112 to the contact mount 220 and be fixed thereto. The wire 20 proceeding from the contact mount 230 can be led through the groove 1114 of the flange section 111 and be wound around the wire winding section 113. The winding runs from the flange section 111 in the direction of the flange section 112. The wire 20 can then be led through the groove 1124 of the flange section 112 to the contact mount 240 and be fixed thereto.
The wires 10 and 20 are guided in a twisted fashion parallel to one another and are arranged jointly and thus simultaneously on the wire winding section during the winding of the wire winding section 113. Both wires have virtually the same length between the respective contact mounts of their ends. The wires 10 and 20 are arranged as a twisted wire pair on the wire winding section 113 in order to improve the impedance characteristic of the inductive component.
The flange section 111 has a surface 1111, a surface 1112 and a surface 1113. The two surfaces 1111 and 1112 of the flange section 111 are arranged opposite relative to the surface 1113 of the flange section 111. The groove 1114 separates the surfaces 1111 and 1112 from one another. The groove 1114 is arranged in the center of the flange section 111 and opens centrally on the wire winding section 113. The flange section 111 thus has two limbs spaced apart from one another via the groove 1114.
The flange section 112 has a surface 1121, a surface 1122 and a surface 1123. The two surfaces 1121 and 1122 of the flange section 112 are arranged opposite relative to the surface 1123 of the flange section 112. The groove 1124 separates the surfaces 1121 and 1122 of the flange section 112 from one another. The groove 1124 is arranged in the center of the flange section 112 and opens centrally on the wire winding section 113. The flange section 112 thus has two limbs spaced apart from one another by the groove 1124.
The flange section 111 has an inner side wall 1115 arranged between the surfaces 1111, 1112 of the flange section 111 and the surface 1113 of the flange section 111 and facing the wire winding section 113. The flange section 111 furthermore has an outer side wall 1116 arranged between one of the surfaces 1111, 1112 and the surface 1113 of the flange section 111 and arranged opposite relative to the inner side wall 1115 of the flange section 111. The flange section 111 furthermore has an inner side wall 1117 arranged between one of the surfaces 1111, 1112 of the flange section 111 and a bottom surface 1119 of the groove 1114 of the flange section 111. The flange section 111 furthermore has an outer side wall 1118 arranged between one of the surfaces 1111, 1112 of the flange section 111 and the surface 1113 of the flange section 111 and arranged opposite relative to the inner side wall 1117 of the flange section 111.
The flange section 112 has an inner side wall 1125 arranged between one of the surfaces 1121, 1122 of the flange section 112 and the surface 1123 of the flange section 112 and facing the wire winding section 113. The flange section 112 furthermore has an outer side wall 1126 arranged between one of the surfaces 1121, 1122 of the flange section 112 and the surface 1123 of the flange section 112 and arranged opposite relative to the inner side wall 1125 of the flange section 112. Furthermore, the flange section 112 has an inner side wall 1127 arranged between one of the surfaces 1121, 1122 of the flange section 112 and a bottom surface 1129 of the groove 1124 of the flange section 112. Furthermore, the flange section 112 has an outer side wall 1128 arranged between one of the surfaces 1121, 1122 of the flange section 112 and the surface 1123 of the flange section 112 and arranged opposite relative to the inner side wall 1127 of the flange section 112.
In the case of the embodiment of the core part 110 as shown in
As is further shown in
In order to close the magnetic circuit in the case of the inductive component, the core part 120, as shown in
In accordance with one possible embodiment, an adhesive layer 310 can be arranged between the surface 1113 of the flange section 111 and the lateral region 1211 of the surface 121 of the core part 120. A further adhesive layer 320 can be arranged between the surface 1123 of the flange section 112 and the lateral region 1212 of the surface 121 of the core part 120. The adhesive layer 310 and the adhesive layer 320 can be applied to the lateral regions 1211 and 1212 of the surface 121 of the core part 120 and/or to the surfaces 1113, 1123 of the flange sections 111, 112 in such a way that a gap S having a gap width of less than 25 μm is formed between the core part 110 and the core part 120 when the core parts 110 and 120 are adhesively bonded together.
In accordance with a further possible embodiment, the adhesive bonding of the core part 110 with the core part 120 can be carried out by an adhesive layer 310 being arranged above a gap S between the side wall 123 of the core part 120 and one of the outer side walls 1116 and 1118 of the flange section 111. A further adhesive layer 320 can be arranged above a gap S between the side wall 123 of the core part 120 and one of the outer side walls 1126, 1128 of the flange section 112. In this embodiment, the adhesive layers 310 and 320 are not applied between the respective contact areas of the core parts 110 and 120, but rather are applied laterally at the two core parts. As a result, the gap width between the core parts 110 and 120 can be reduced to a gap width that is less than 10 μm.
In accordance with one advantageous embodiment, the surface 1113 of the flange section 111 and/or the lateral region 1211 of the surface 121 of the core part 120 can be ground. Likewise, the surface 1123 of the flange section 112 and/or the lateral region 1212 of the surface 121 of the core part 120 can be ground. By way of example, mirror grinding or so-called lapping can be used for grinding the surfaces. As a result, even with relatively coarse granulation, very high surface qualities can be achieved owing to the small material removal. On account of the abovementioned types of grinding, the surfaces 1113 and 1123 and the lateral regions 1211 and 1212 of the surface 121 are very smooth, such that the gap width between the core parts 110 and 120 can be reduced again as a result when the core parts 110 and 120 are joined together.
On account of the large and planar contact area and the small gap width associated therewith between the core part 110 and the core part 120, large inductance values can be achieved with the inductive component.
In the case of the embodiment 2 of the inductive component, the core part 120 can have one of the embodiments shown in
In a manner similar to that in the case of the embodiment shown in
Only the differences in the embodiment 2 in comparison with the embodiment 1 of the inductive component are discussed below. In this case, besides
The wires 10 and 20 can be guided through the groove 1114 of the flange section 111 from the contact mounts 210 and 230 onto the wire winding section 113. After the wires have been wound around the wire winding section 113, the wires 10, 20 are guided through the groove 1124 of the flange section 112 and fixed to the contact mounts 220, 240. In contrast to the embodiment of the inductive component 1 as shown in
In the case of the embodiment shown in
In this case, the wires 10 and 20 are wound onto the wire winding section 113 in such a way that after guiding the wires 10 and 20 through the groove 1114 of the flange section 111, a first turn n1, mi of the wires 10, 20 is arranged directly on the wire winding section 113 alongside the respective inner side wall 1115 of the flange section 111. Subsequently to the turn n1, m1, at least one further turn n2, m2, n3, m3 is arranged on the first turn n1, m1. Consequently, the inductive component comprises a multiplicity of winding sections having turns arranged one above another. After a first winding section has been wound from the turns n1, m1, n2, m2 and n3, m3, a further turn n4, m4 is arranged directly onto the wire winding section 113 alongside the first turn n1, m1, further turns n5, m5 and n6, m6 again being arranged above said further turn. A second winding section comprises for example the turns n4, m4, n5, m5 and n6, m6. In this way, between the inner side wall 1115 of the flange section 111 and the inner side wall 1125 of the flange section 112, the winding space is filled with a multiplicity of winding sections each comprising turns arranged one above another.
By virtue of the use of the twisted wires 10 and 20 and the position of the wires 10 and 20 in the various turns, as shown in
The wires 10 and 20 are wound on the wire winding section 113 in such a way that after guiding the wires 10 and 20 through the groove 1114 of the flange section 111, a first winding part comprising the turns n1, m2, . . . , nj, mj of the wires 10, 20 and a second winding part comprising the turns nj+i, mj+1, . . . , nx, mx, are arranged on the wire winding section 113. The turns n1, m2, . . . , nj, mj are arranged directly alongside one another on the wire winding section 113 alongside the first inner side wall 1115 of the flange section 111. In each turn of the first winding part, the wires 10 and 20 are arranged in the same position relative to one another. Subsequently to the first winding part, the second winding part is arranged directly onto the wire winding section 113 between the first winding part and the inner side wall 1125 of the flange section 112. In each turn of the second winding part nj+i, mj+1, . . . , nx, mx, the wires 10 and 20 are arranged in the same position relative to one another. However, the position of the wires 10 and 20 in the first winding part is different than the position of the wires 10 and 20 in the second winding part. The crossover of the positions of the wires takes place at half of the length of the wire winding section 113. By virtue of the type of winding shown in
The wires 10 and 20 can be wound onto the wire winding section 113 in a manner arranged one above another proceeding from one of the side walls 1115, 1125 as far as the other of the side walls, wherein the vertical position of the wires in the individual turns is transposed in the center of the wire winding section. In accordance with a different winding method, the wires 10 proceeding from the side wall 1115 in the direction of the side wall 1125 and the wires 20 proceeding from the side wall 1125 in the direction of the side wall 1115 can be wound around the wire winding section 113, wherein in the center of the wire winding section 113 the wires 10 are wound over the wires 20 as far as the side wall 1125 and the wires 20 are wound over the wires 10 as far as the side wall 1115.
The twisted type of winding of the wires 10 and 20 as shown in
Number | Date | Country | Kind |
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10 2014 103 324.8 | Mar 2014 | DE | national |
This patent application is a national phase filing under section 371 of PCT/EP2015/052524, filed Feb. 6, 2015, which claims the priority of German patent application 10 2014 103 324.8, filed Mar. 12, 2014, each of which is incorporated herein by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2015/052524 | 2/6/2015 | WO | 00 |