EP4675865A1

EP4675865A1 - Electrical connector for automotive applications

Info

Publication number: EP4675865A1
Application number: EP24186473.5A
Authority: EP
Inventors: Jörg ACKERMANN
Original assignee: Aptiv Technologies AG
Current assignee: Aptiv Technologies AG
Priority date: 2024-07-04
Filing date: 2024-07-04
Publication date: 2026-01-07

Abstract

The present invention relates to an electrical connector for automotive applications, comprising a housing; at least one electrical terminal; at least one tubular shielding in which the electrical terminal is arranged at least partially, wherein the shielding and the housing are separate pieces, and wherein the shielding is attached and electrically connected to the housing.

Description

1. Technical field

The present invention relates to an electrical connector for automotive applications.

2. Technical background

Electrical connectors are used in automotive applications to electrically connect different modules of a vehicle. Examples include actuators, sensors and control modules. A connector usually comprises an electrical terminal, a housing and related parts that terminate a cable for the purpose of providing a suitable electrical connection and disconnection. The electrical connection may support supply voltages but also data lines which are operated at high frequencies, e.g. up to 20 GHz. Therefore, an electrical connector for automotive applications needs an electromagnetic shielding to protect the electrical connection from the environment.
Electromagnetic shielding may be achieved by forming the entire electrical connector from a metal material such as steel or aluminum, e.g. by die casting. However, a problem arises in automotive applications in that fretting corrosion occurs at the contact surface of the connector due to vibrations. This is especially pertinent in truck applications requiring the fulfillment of high vibration classes. To address fretting corrosion, the connectors are usually coated, e.g. with copper, nickel or zinc in combination with a tin, silver or gold coating.
Such a coating is usually applied by an electro-galvanic process in which the coating is bonded to the metal in order to protect against corrosion. Due to the nature of such process, considerably less coating material is deposited inside of cavities (e.g. connector tunnels) compared to the outside of the housing. However, for protecting against fretting corrosion, the coating inside of the cavities needs a certain thickness as the electrical and mechanical contact is (also) made in the cavities of the connector. For example, while a coating with a thickness of 1 µm may build up inside of a cavity of a connector, a coating with a thickness of 20-40 µm may build up on the outside of the connector housing. However, a uniform thickness on the outside and the inside would be more desirable.
Thus, conventional methods of manufacturing electrical connectors for automotive applications have at least three disadvantages: First, the uneven distribution of coating material inside and outside of cavities leads to a waist of excess material and increases the production costs. Second, as the build-up of the coating thickness inside cavities of a connector during an electro-galvanic process takes considerably longer than at the outside of the housing of the connector, the manufacturing time is increased. Third, a coating is inevitably even applied where it does not fulfill a technical purpose, for example at locations of the housing of the connector which do not take part in the mechanical and/or electrical connection at all.

3. Summary of the invention

The above problems are addressed by the present invention which is defined in the independent claims. Advantageous embodiments are contained in the dependent claims.
Accordingly, the present invention provides an electrical connector for automotive applications, comprising a housing; at least one electrical terminal; at least one tubular shielding in which the electrical terminal is arranged at least partially, wherein the shielding and the housing are separate pieces, and wherein the shielding is attached and electrically connected to the housing.
Thus, according to the invention, the tubular shielding is a separate piece from the housing. Therefore, the tubular shielding can be subject to a coating process. The housing does not need a coating and would not be subject to a coating process. Alternatively, the housing could be coated with a different, cheaper coating (e.g. without expensive silver or gold) than the shielding because no fretting prevention is necessary. In this way, a coating is applied where it is really needed, namely at the tubular coating. This saves coating material and associated costs. It also substantially decreases the manufacturing time because a desired thickness of the coating builds up much faster on the much smaller tubular shielding which is also better accessible for the coating material instead of the entire connector. By attaching and electrically connecting the tubular shielding to the housing, the entire connector becomes electromagnetically shielded.
The invention even allows for manufacturing a connector for automotive applications without the need for any coating at all. For example, the tubular shielding may be made from a material which is naturally insusceptible to fretting corrosion. Examples include nickel silver or stainless steel. In contrast, the housing may be made from a less expensive material such as steel or aluminum and may for example be manufactured in a cost-effective die cast process.
The electrical connector may be a data connector. An electromagnetic shielding is especially effective with data connectors as the unfavorable electromagnetic environment in a vehicle may make unshielded data transmission even impossible. Thus, the invention may advantageously applied to data connectors.
The shielding may be made from a bent metal sheet. This has the advantage that the metal sheet may be coated prior to bending which substantially increases the deposition rate because the coating material may better reach the surface of the flat metal sheet compared to an inner surface of a tubular structure. It would even be possible to apply the coating to just one side of the flat metal sheet which again saves material, costs and time.
The shielding may be made from copper, nickel silver alloy or stainless steel. These materials turn out to provide an effective protection against fretting corrosion in conjunction with a suitable coating and yet provide the desired electromagnetic shielding effect. Some of these materials, e.g. stainless steel, may even be used without a coating.
An inner surface of the shielding may be more abrasion-resistant than a surface of the housing. Thus, abrasion resistance is present where it is needed, namely at the electrical and mechanical contact surfaces of the connector. The housing may be made from a less abrasion resistant and less costly material. In addition, it may be formed in a cost-effective process such as die casting.
An inner surface of the shielding may comprise a coating. Thus, the coating is present in locations where abrasion-resistance and protection from fretting corrosion is needed.
The coating of the inner surface of the shielding may substantially comprise the same thickness as an outer surface of the shielding. Thus, the thickness of the coating is homogeneous and compared to conventional connectors no excess material is present. A homogeneous coating is possible because the tubular shielding is a separate piece from the housing. Thus, it may either be made from a material being insusceptible from fretting corrosion or may be specifically coated for that purpose. Unlike prior art connectors, the housing may be made from an entirely different material and may comprise no coating.
The coating may be an electroplating. The present invention is well suited for electroplating because it allows to treat the tubular shielding independently from the housing. Thus, the electroplating process may specifically targeted to the shielding for optimal results and minimization of coating material, time and costs.
Two opposing ends of the metal sheet may be connected by at least one weld point. This is particularly advantageous in case of a shielding that is formed from a flat metal sheet by bending as its mechanical stability is improved by the weld point.
The shielding may be press fit into the housing. In this way, a good mechanical and electrical connection is achieved between the shielding and the housing. At the same time, press fitting allows such connection to be made without additional components, such as glue, and reduces the number of additional process steps to a minimum.
The housing may be die-cast. Die-casting allows for rapid production rates and dimensional accuracy at comparably low costs. Thanks to the invention, the housing can be manufactured with such advantageous process, whereas the shielding may be manufactured in a separate process which is more targeted for the specific requirements of the shielding such as abrasion resistance and low electrical contact resistance.
The housing may be adapted to be mounted on a printed circuit board. Thus, the electrical connector may be used for connecting a cable to the printed circuit board. To this end, the cable may be terminated with a counterpart to the connector, e.g. a plug, to be mechanically and electrically connected to the connector. The housing may for example comprise at least one pin or fin to be soldered to the printed circuit board. It should be noted, however, that the connector according to the invention may also be used as a plug, i.e. terminating a cable.
The housing and the shielding may be made from different materials. In this way, the shielding may be specifically target for high abrasion resistance and low electrical contact resistance, whereas the housing may be made from a more inexpensive material and/or with a more inexpensive manufacturing process.
The shielding may comprise an oval, triangular or square shape. In general, the shielding may be adapted to mate with a corresponding counterpart, e.g. of a plug or another connector. As the shielding is not made in one piece with the housing, it is possible to manufacture housings which are to be combined with shieldings of different shapes which saves manufacturing costs.

4. Brief description of the drawings

Possible embodiments of the present invention are described in more detail in the following detailed description with reference to the following figures. These figures show:

Fig. 1:: An exemplary embodiment of an electrical connector for automotive applications according to the present invention;
Fig. 2A:: A top view of the exemplary connector of Fig. 1;
Fig. 2B:: A cross sectional view of the connector of Fig. 1 along the line A-A in Fig. 2A; and
Fig. 3:: Another embodiment of an electrical connector according to the invention.

5. Detailed description of possible embodiments

For the sake of brevity, only a few embodiments will be described below. The person skilled in the art will recognize that the features described with reference to these specific embodiments may be modified and combined in different ways and that individual features may also be omitted. The general explanations in the sections above also apply to the more detailed explanations below.
Fig. 1 illustrates an exemplary embodiment of an electrical connector 1 for automotive applications according to the present invention. The electrical connector 1 in this example is a data connector for electrically connecting for example sensors, actuators and control units in a vehicle. As such, the electrical connector 1 comprises a number of terminals (not depicted in Fig. 1) which are adapted to make an electrical connection to corresponding counterparts, e.g. another connector or a plug.
The connector 1 comprises a housing 2 which may for example be made from a metal material, such as steel or aluminum. The housing 2 can for example be manufactured in a die-casting process. The housing 2 thus has the function of a shield housing.
The connector 1 also comprises four tubular shieldings 3 in which terminals are arranged at least partially (not depicted in Fig. 1). The shieldings 3 are attached and electrically connected to the housing 1. As depicted in the exploded view of Fig. 1, the shieldings 3 and the housing 2 are separate pieces. As such, they can be manufactured in different manufacturing processes, from different materials and/or using different surface treatments. For example, the shieldings 3 can be made from copper, nickel-silver alloy or stainless steel, whereas the housing 2 can be made from steel or aluminum. In another example, the shieldings 3 are coated to e.g. raise the abrasion resistance and avoid fretting corrosion, whereas the housing 2 can be uncoated.
In the example of Fig. 1, the shieldings 3 are press fit into the housing 2. In other embodiments, a different technique may be used to attach the shieldings 3 to the housing 2, e.g. glueing, screwing or welding. In any case, a firm mechanical connection as well as a good electrical connection between the shieldings 3 and the housing 2 needs to be made. Generally, the number of shieldings 3 can be different in other embodiments, for example a connector according to the invention comprising a single shielding is possible.
In the example of Fig. 1, the shieldings 3 are made from bent metal shields. To this end, a flat metal sheet is formed into the tubular shape depicted in Fig. 1. To this end, cold or hot forming may be used, depending on the material of the metal shields. Also, different shapes of the shieldings 3 may be obtained by bending such as oval, triangular or square shaped.
Advantageously, at least one surface of the metal shields can be coated before bending, i.e. in the flat configuration. For example, the surface of the flat metal shield which later forms the mechanical and electrical contact surface can be coated to increase abrasion resistance and, therefore, to increase its resistance to fretting corrosion which frequently occurs in environments being subject to vibration, e.g. in cars or trucks. In the example of Fig. 1, the electrical and mechanical contact surface of the tubular shieldings 3 is the inner surface of the respective tube. Furthermore, in the embodiment of Fig. 1, also the opposing, outer surface of the shieldings 3 is coated and the coating has substantially (i.e. within manufacturing tolerances due to the coating process) the same thickness as the inner coating.
In the embodiment of Fig. 1, the coating is obtained by an electroplating process. The thickness of the coating depends on various factors such as the required vibration profile. The coating may comprise several different materials, e.g. for a die-cast part, a copper layer may be applied first, followed by a nickel layer and then a tin, silver or gold coating as the top coating. With a sheet material made of a copper alloy, the first copper layer could be omitted. However, the intermediate layer of nickel is only necessary if whisker formation is to be expected during the application. With reference to the top coating, this may be between 1-3 µm for silver and 0.2-1.2 µm for gold. It is essential to be able to control the coating thickness on the inside of the pipe independently of the coating on the outside which is an important benefit of the present invention.
To increase the mechanical stability of the shieldings 3, their opposing ends are connected by a weld point 4. In other embodiments, the shieldings do not comprise such a weld point.
The housing 2 of the connector 1 of the embodiment of Fig. 1 is adapted to be mounted on a printed circuit board. To this end, the housing 2 comprises a number of pins 5 which are adapted to fit into corresponding via holes of a printed circuit board and to be welded to the printed circuit board (not shown in the figures).
Fig. 2A is a top view of the exemplary connector 1 of Fig. 1 and Fig. 2B is a cross sectional view of the connector 1 along the line A-A in Fig. 2A. In Fig. 2B, two terminals 6 of the connector 1 are shown in cross section. The terminals 6 are adapted to make an electrical connection to corresponding counterparts, e.g. another connector or a plug. Thus, the terminals 6 form signal pins or contacts. In Fig. 2B, those ends of the terminals 6 are shown which are adapted to fit into corresponding via holes of a printed circuit board. The opposing ends of the terminals 6 are arranged in the shieldings 3 and are adapted to make an electrical connection to corresponding counterparts, e.g. another connector or a plug.
Fig. 3 depicts another embodiment of an electrical connector 1 according to the invention. Fig. 3 is an exploded view to better illustrate the components of the connector 1 which are basically the same as in the previously described embodiment. As shown in Fig. 3, the connector 1 comprises eight electrical terminals, four of which are exemplarily denoted by reference numeral 6. The terminals 6 are arranged in pairs and each pair is partially arranged in a corresponding tubular shielding 4. Therefore, a terminal pair forms a port via which data is transmitted. This means that in this example it is a four-port connector with the possibility of transmitting four different signals.. The two terminals or signal contacts 6 of each terminal pair are cast in a corresponding retainer 7, two of which are exemplarily denoted by reference numeral 7. The retainers 7 are dielectric and the signal contacts 6 are embedded therein.
The electrical connector 1 of the example of Fig. 3 also comprises back shield plates 8 that are pressed into the die-cast housing 2 from below. They form the back shielding of the component so that the shielding is also tight and no radiation radiates backwards out of the connector 1. The component shown is a 4-port connector. A separate shield tube is used for each port connection. In other embodiments, the connector would comprise a different number of ports, e.g. 1-6 ports. This means that more or less shield tubes would be used.

List of reference numerals

1: Connector
2: Housing
3: Shielding
4: Weld point
5: Pin
6: Terminal
7: Retainer
8: Shield plates

Claims

Electrical connector for automotive applications, comprising:
a housing;

at least one electrical terminal;

at least one tubular shielding in which the electrical terminal is arranged at least partially, wherein the shielding and the housing are separate pieces, and

wherein the shielding is attached and electrically connected to the housing.
Electrical connector according to claim 1, wherein the electrical connector is a data connector.
Electrical connector according to one of claims 1 or 2, wherein the shielding is made from a bent metal sheet.
Electrical connector according to one of claims 1-3, wherein the shielding is made from copper, nickel silver alloy or stainless steel.
Electrical connector according to one of claims 1-4, wherein an inner surface of the shielding is more abrasion-resistant than a surface of the housing.
Electrical connector according to one of claims 1-5, wherein an inner surface of the shielding comprises a coating.
Electrical connector according to claim 6, wherein the coating of the inner surface of the shielding substantially comprises the same thickness as an outer surface of the shielding.
Electrical connector according to one of claims 6-7, wherein the coating is an electroplating.
Electrical connector according to one of claims 3-8, wherein two opposing ends of the metal sheet are connected by at least one weld point.
Electrical connector according to one of claims 1-9, wherein the shielding is press fit into the housing.
Electrical connector according to one of claims 1-10, wherein the housing is die-cast.
Electrical connector according to one of claims 1-11, wherein the housing is adapted to be mounted on a printed circuit board.
Electrical connector according to one of claims 1-12, wherein the housing and the shielding are made from different materials.
Electrical connector according to one of claims 1-13, wherein the shielding comprises an oval, triangular or square shape.