Patent Grant
11355889
This application claims the benefit of the filing date under 35 U.S.C. § 119(a)-(d) of European Patent Application No. 19193937.0, filed on Aug. 27, 2019.
The present invention relates to a cover assembly and, more particularly, to a cover assembly for the protection of a bond between electrical conductors of a high-frequency data transmission line.
In the field of data transmission, transmission lines usually consist of multiple components such as connectors, cables, wires, receptacles, and the like. These transmission line components are interconnected in order to establish the necessary signal channel. Said interconnections can be realized through a connection device, e.g. a plug and socket mechanism, or a permanent bond. The connection device needs to provide for a reliable electrical contact between the transmission line components. In case of permanent bonds, a reinforcement is further provided, surrounding the permanent bond to increase the mechanical stability of the permanent bond.
In applications where high-frequency data transmission is required, the connection device and the reinforcement themselves may have a negative influence on the properties of the signal channel, which deteriorates the signal quality and transmission performance, respectively.
A cover assembly includes a protective cover having an impedance control structure and a plurality of electrical conductors conducting electrical signals of a high-frequency data transmission. The electrical conductors extend through the protective cover in a transmission direction and are overlappingly bonded to each other at a bond location located within the protective cover. The impedance control structure adjusts an impedance of the bond location to a predefined value.
The invention will now be described by way of example with reference to the accompanying Figures, of which:
In the following, exemplary embodiments of the invention are described with reference to the drawings. The shown and described embodiments serve explanatory purposes only. The combination of features shown in the embodiments may be changed according to the description. For example, a feature which is not shown in an embodiment but described may be added, if the technical effect associated with this feature is beneficial for a particular application. Vice versa, a feature shown as part of an embodiment may be omitted if the technical effect associated with this feature is not needed in a particular application. In the drawings, elements that correspond to each other with respect to function and/or structure have been provided with the same reference numeral.
First, the structure of a cover assembly 1 according to the present invention is explained with reference to the exemplary embodiments shown in
The cover assembly 1, as shown in the embodiment of
The cover assembly 1, as shown in
The protective cover 4 is a substantially cuboid part made of an insulation material with a relative permittivity higher than air. In an embodiment, the high permittivity insulation material for the protective cover 4 is a material with a relative permittivity in a range between 9 and 10. An insulation material with incorporated ceramic powder may be used as the high permittivity insulation material for the protective cover 4.
More particularly, the protective cover 4 may be an overmolded part 18, as shown in the embodiments of
The contact carrier 16 is also a substantially cuboid part made of an insulation material with a relative permittivity higher than air. The contact carrier 16 has a contact section 20 with a traverse cross-sectional area smaller than the protective cover 4 and a bulged section 22 with a traverse cross-sectional area equal to the protective cover 4. The contact carrier 16, in an embodiment, has a step-like transition between the contact section 20 and the bulged section 22.
The pair of electrical conductors 5, the first wire 6a and the second wire 6b, extend parallel to each other through the shielded electrical cable 10 in a transmission direction T, as shown in
The first contact element 12a and the second contact element 12b, as shown in
As shown in
The bonding portion 30, as shown in
As shown in
Centerlines of the pair of signal paths 38a, 38b may be parallel to each other along the entire length of the cover assembly 1. More particularly, the wire pitch of the first and second wire 6a, 6b may be equal to the contact pitch of the first and second contact element 12a, 12b. This embodiment especially prevents a spreading of the wires, which would lead to a sharp bend. Thus, at least one possible cause of signal reflection is eliminated in order to further improve signal integrity.
The first bond location 42a and the second bond location 42b, shown in
In general, impedance is the property of electrical conductors measuring their resistance against the flow of an alternating current. Impedance is influenced by several factors, such as the material and dimensions of the electrical conductor itself, by the mean relative permittivity of the medium surrounding the conductor (dielectric material), and by other electrically conductive or capacitive components in proximity of the electrical conductor, especially the relative distance between the respective surfaces.
If during the transmission of an electrical signal from a signal source to a signal receiver (load) via a transmission line, the impedance of the load and the impedance of the transmission line is not matched (impedance mismatch), signal reflection may occur. Signal reflection impairs signal integrity and is therefore an unwanted phenomenon. The cause of such an impedance mismatch and subsequent signal reflection may be a non-linear change in the cross-section of an electrical conductor of the transmission line or a discontinuity in the material surrounding the electrical conductor as well as a sharp bend in the course of the transmission line.
Due to its role as a dielectric material, the insulation material of the protective cover 4, which surrounds the first signal path 38a and the second signal path 38b, also affects the impedance of the first signal path 38a and the second signal path 38b. In order to compensate for said effects on the first bond location 42a, the second bond location 42b, and the protective cover 4, at least one impedance control structure 46 may be implemented on the protective cover 4. The impedance control structure 46 on the protective cover 4 adjusts the impedance of the at least two electrical conductors 5 to a predefined value according to the frequency of the data transmission. Thus, the effects of the bond locations 42a, 42b and of the protective cover 4 are compensated for.
Matching the impedance of the transmission line to the impedance of the load eliminates causes of impedance mismatch. The impedance of the transmission line should be adjusted to a predefined value; such a predefined value may be the impedance of the load. This compensates for at least one cause of impedance mismatch and thus reduces signal reflection. Therefore, the signal integrity of the transmitted signal is substantially improved and the reliability of the signal transmission increased.
For example, the at least one impedance control structure 46 may be at least one recess 44 locally formed on the outer surface 40 of the protective cover 4 in an area, where the first signal path 38a and the second signal path 38b are surrounded by the insulation material of the protective cover 4, while the first signal path 38a and the second signal path 38b exhibit an increased cross-section. In particular, the at least one recess 44 may result in air-filled space in said area. For this, the at least one recess 44 may be e.g. a substantially cuboid, cylindrical, conic, semi-spherical, trapezoidal or stadium-shaped cut-out in the insulation material of the protective cover 4. The cut-out may at least partly extend towards the first signal path 38a and/or the second signal path 38b. Furthermore, the cut-out may extend into another direction, preferably the transmission direction T, at least along the entire length of the first bond location 42a and/or the second bond location 42b.
Additionally or alternatively, the protective cover 4 may comprise a lead-through hole 48 as an impedance control structure 46, as shown in
As shown in
The at least one lead-through hole 48 is also an impedance control structure 46 that allows for an easy adjustment of at least one impedance-influencing factor, namely the mean relative permittivity of the dielectric material. In combination with the embodiment comprising a pair of signal paths 38a, 38b, the at least one lead-through hole 48 may extend between the pair of signal paths 38a, 38b. This way, an air-filled space may be created between the pair of signal paths 38a, 38b, which results in a lower mean relative permittivity of the dielectric material and in an increased impedance of the pair of signal paths 38a, 38b, since air has a lower relative permittivity than the insulation material. Therefore, the at least one lead-through hole 48 may be implemented in applications where the impedance of the pair of signal paths 38a, 38b needs to be increased in order to arrive at the predefined value and to compensate for the influence of the at least one bond location 42a, 42b and of the protective cover 4.
As can further be seen from
In the embodiment shown in
The pair of cover halves 70 may comprise an impedance control structure 46 in that a high permittivity insulation material is used to form at least a part of each cover half 70. In an embodiment, an insulation material with incorporated ceramic powder may be used as a high permittivity insulation material.
Each of the pair of cover halves 70 may further comprise an inner wall 78, at least partly spacing apart the first signal path 38a from the second signal path 38b. The inner wall 78 may also be formed in the overmolded part 18, as can be seen in
Alternatively, the capacitive elements 80 may be separate metal plates positioned into holding grooves 92 on at least one outer surface of the protective cover 4, or glued thereto. Furthermore, the capacitive elements 80 may be woven metal parts surrounding the pair of pre-fabricated cover halves 70.
The at least one capacitive element 80 is an impedance control structure 46 that allows for an adjustment of at least one impedance-influencing factor, namely the relative distance between the surfaces of the at least two electrical conductors 5 and the surface of the at least one capacitive element 80. In particular, said relative distance is shortened by positioning the at least one capacitive element 80 on the surface of the protective cover 4 and thus in proximity of the at least two electrical conductors 5. As a result, the impedance of the at least two electrical conductors 5 is lowered. Subsequently, the at least one capacitive element 80 may be utilized in applications where the impedance of the at least two electrical conductors 5 needs to be reduced in order to arrive at the predefined value, and to compensate for the influence of the at least one bond location 42a, 42b and of the protective cover 4. This could be the case, for example, in areas where the at least two electrical conductors 5 are surrounded by air, e.g. due to air-filled gaps in the protective cover 4 caused be manufacturing inaccuracies
Any of the above-mentioned embodiments of the at least one impedance control structure 46 may be aligned with the at least one bond location 42a, 42b. More particularly, the at least one impedance control structure 46 may be in the vicinity of and/or locally limited to the area of influence of the at least one bond location 42a, 42b, thus concentrating and maximizing the effect of the at least one impedance control structure 46.
As can be seen from
The connector 2 shown in
In
In
In
Further, in
A method for overmolding a bond 42a, 42b between at least one wire 6 of a cable 10 and at least one contact element 12 with a protective cover 4 made of insulation material, comprises steps of providing the at least one contact element 12; providing the at least one wire 6; positioning the at least one contact element 12 and the at least one wire 6 in a partially overlapping position; bonding the at least one contact element 12 and the at least one wire 6 e.g. by welding, such as by compaction welding and/or resistive welding or alternatively by similar appropriate methods such as soldering, brazing, etc.; surrounding the bonds 42 with the cast 106, the cast 106 having at least one core 110, which forms the at least one impedance control structure 46 in the insulation material; injecting the insulation material into the cast 106; and removing the cast 106 and the at least two cores 110 after the hardening of the injected insulation material.
This method allows the manufacturing of the protective cover 4 as the overmolded part 18, thus proving a means for reliably transmitting high-frequency signals, in particular in the gigahertz range. Simultaneously, this method allows forming the at least one impedance control structure 46 in the insulation material of the protective cover 4. It therefore shortens the time for manufacturing of the overmolded protective cover 4.
The above described method may be further improved by adding one or more of the following optional steps. Hereby, each of the following optional steps is advantageous on its own, and may be combined independently with any other optional step.
In a first embodiment, the method may comprise the steps of providing the at least one contact element 12 in a 360° accessible orientation as shown in
In another embodiment, the method may comprise the steps of providing a first contact element 12a; providing a second contact element 12b; providing a first wire 6a; providing a second wire 6b; positioning the first contact element 12a and the first wire 6a in a partially overlapping position, to form a first signal path 38a; and positioning the second contact element 12b and the second wire 6b in a partially overlapping position, to form a second signal path 38b.
In yet another embodiment the method may comprise the steps of fixating the first and second signal path 38a, 38b with at least two cores 110 from at least two opposite directions, such as two opposite directions perpendicular to the transmission direction T.
According to another embodiment, the method may comprise the steps of inserting a blade 112 between the first and second signal path 38a, 38b, the blade 112 being an integral part of one of the at least two cores 110. The blade 112 may function as an additional or alternative spacer between the first and second signal path 38a, 38b, further preventing an unwanted movement of the first and second signal path 38a, 38b during the injection of the insulation material. The blade 112 thus may further increase the reliability of the overmolding process. Moreover, a combination of the at least two cores 110 and the blade 112 allows for the manufacturing of the overmolded protective cover 4 itself, while simultaneously forming the at least one lead-through hole 48 as an impedance control structure 46 in the insulation material of the protective cover 4.
| Number | Date | Country | Kind |
|---|---|---|---|
| 19193937 | Aug 2019 | EP | regional |
| Number | Name | Date | Kind |
|---|---|---|---|
| 6203369 | Feldman | Mar 2001 | B1 |
| 7004793 | Scherer | Feb 2006 | B2 |
| 7722394 | Feldman | May 2010 | B2 |
| 7731528 | Feldman | Jun 2010 | B2 |
| 7744403 | Barr | Jun 2010 | B2 |
| 9608590 | Hamner | Mar 2017 | B2 |
| 10103498 | Maesoba | Oct 2018 | B2 |
| 10283891 | Maesoba | May 2019 | B2 |
| 10297932 | Maesoba | May 2019 | B2 |
| 10305202 | Maesoba | May 2019 | B2 |
| 20190006785 | Maesoba | Jan 2019 | A1 |
| 20190157809 | Maesoba | May 2019 | A1 |
| 20190252806 | Maesoba | Aug 2019 | A1 |
| Entry |
|---|
| Partial European Search Report, dated Feb. 20, 2020, 14 pages. |
| Extended European search report dated Jul. 20, 2021 in Appln. No. 19193937.0-1201, 13 pp. |
| Number | Date | Country | |
|---|---|---|---|
| 20210066858 A1 | Mar 2021 | US |
