WO2016146553A1

WO2016146553A1 - Electrical connector kit, electronic component, and assembly method

Info

Publication number: WO2016146553A1
Application number: PCT/EP2016/055382
Authority: WO
Inventors: Daniel Walldorf; Calogero Mauro Buscemi; Markus Strelow; Christian Schrettlinger; Frank Wolf; Steffen Burger; Chris Buechling; Michael Fredrick Laub; Ulrich Buchmann
Original assignee: TE Connectivity Germany GmbH
Current assignee: TE Connectivity Germany GmbH
Priority date: 2015-03-13
Filing date: 2016-03-11
Publication date: 2016-09-22
Anticipated expiration: 2017-09-13
Also published as: JP2018511913A; US20180006390A1; US10403995B2; JP6472897B2; CN107431306A; EP3067992A1; EP3067992B1; CN107431306B

Abstract

The present invention relates to an electrical connector kit for an electronic component and in particular for an inductive proximity sensor. Furthermore, the present invention relates to an assembly method for fabricating such an electronic component. An electrical connector kit for a circuit carrier (102) comprises at least one interface element (106) which is attachable to said circuit carrier (102) and which has at least one inner contact (108) for contacting at least one electrically conductive lead on said circuit carrier (102), said interface element (106) further comprising an electrically connecting interface (110) for contacting a peripheral connector (112, 14). A set of at least one first and second peripheral connectors (112, 114) is provided, each being connectable to said connecting interface(110), wherein, for contacting at least one external electronic component, said first and second peripheral connectors (112, 114) have peripheral contact elements (148, 152, 124) which differ from each other.

Description

ELECTRICAL CONNECTOR KIT, ELECTRONIC COMPONENT, AND ASSEMBLY METHOD

The present invention relates to an electrical connector kit for an electronic component and in particular for an inductive proximity sensor. Furthermore, the present invention relates to an assembly method for fabricating such an electronic component. The principles according to the present invention can be used advantageously for inductive sensors, and especially for proximity sensors. Inductive sensors are well known in the art and usually comprise a coil that is wound around a ferrite core and is used to form an oscillator. The inductive proximity sensor comprises a circuit board which is equipped with integrated circuits, for instance an electronic analyzing unit and an amplifying circuit. When a metallic object approaches the sensor, the oscillator is detuned and thus a signal in response to the approaching object can be generated. Such inductive proximity sensors are components fabricated in mass production and therefore the assembly has to be simple and cost-efficient.

Typically, all components of the sensor are integrated within an elongated housing: The sensor coil is arranged at a front end of the sensor, whereas a peripheral contact element for connecting the sensor to external electronic components, i. e. a plug connector or an electrical lead, is arranged at the opposing back end of the sensor. A circuit carrier, usually a printed circuit board (PCB), carries the sensor electronics and is electrically connected to the peripheral contact element.

There exist different concepts for equipping industrial sensors with a plug connector forming the peripheral contact element. A conventional plug connector is screwed or pressed into the housing and can then be connected to the PCB by means of electrically conductive leads which are manually soldered. Alternatively, a flexible printed circuit board can be soldered directly to the plug connector. Finally, a conventional plug connector can be assembled with a cable and an edge connector which is connected to the PCB. In particular the latter variant has the disadvantage that it needs a lot of space.

It is further known to directly assemble the plug connector on the PCB and mount the PCB with the plug connector in a housing, so that the plug connector stays accessible via a suitable opening in the housing.

According to a further conventional arrangement, a plurality of contact pins are assembled individually on the PCB and allowed to extend to the outside through a respective support structure in the housing. Finally, it is known to form a plug connector at the housing by means of an overmolding technique and to contact the PCB by means of a lead frame which is pressed-in or soldered to the PCB.

Some applications require that the sensor is equipped with a cable of a suitable length, a so- called pigtail, instead of a plug connector. Such a cable can firstly be soldered manually to the printed circuit board. Secondly, the cable can be provided with an edge connector which is a rather space consuming concept. Conventional cable connections achieve a sealed encapsulation of the sensor components as well as the necessary strain relief by providing an additional overmolding step. Alternatively, a cable gland (also called PG, Panzergewinde, threaded fitting) is often used for providing sealing and strain relief.

When fabricating such an inductive sensor, it is desirable to introduce the distinction concerning the particular peripheral contact element at a point within the assembly process as late as possible and preferably without manual soldering steps. The object underlying the present invention therefore is to provide an electrical connector kit for a circuit carrier that provides a particularly robust and reliable electrical contacting of the circuit carrier and whereby the assembly of a plug connector or a cable is delayed to an assembly step late in the fabrication process.

This object is solved by the subject matter of the independent claims. Advantageous embodiments of the present invention are the subject matter of several dependent claims. The present invention is based on the idea that by providing an electrical connector kit for a circuit carrier with at least one interface element which is attachable to the circuit carrier and has at least one in a contact for contacting at least one electrically conductive lead on the circuit carrier and further comprises an electrically connecting interface for contacting a peripheral connector, the decision on the particular peripheral connector can be postponed until one of the very last fabrication steps. According to the present invention, the kit comprises a set of at least one first and second peripheral connector each being connectable to the connecting interface of the interface element. The first and second peripheral connectors are characterized by different peripheral contact elements, such as a plug connector or an electrical lead, for contacting an external electronic component. For connecting the interface element to the circuit carrier, reliable automated techniques can be used. Hence, the connection between the circuit board and the peripheral connector is much more reliable than manually soldered connections.

According to an advantageous embodiment of the present invention, the peripheral contact region of the first peripheral connector comprises a plug connector, for instance a male plug connector which can be connected to a mating female plug connector belonging to an external electronic component. The second peripheral connector may comprise as its peripheral contact element an electrical lead for forming a pigtail. Thus, all requirements regarding a particular type of peripheral contact element can easily be fulfilled.

According to the present invention, the interface element can either be provided as a part separate from the first and second peripheral connectors, or one interface element can be provided for each of the first and second peripheral connectors. When designing the interface element as a separate part, same can for instance be fabricated as a surface mount device (SMD) component which is mounted directly on the printed circuit board before assembling the printed circuit board within the housing. Consequently, a particularly well-defined and robust connection can be established between the interface element and the PCB.

Alternatively, each of the first and second peripheral connectors can be provided with an interface element. Such a construction is for instance advantageous in combination with an edge clamping electrical contact between the interface element and the PCB. For this variant the interface element is assembled with the respective first and second peripheral connectors already when compiling the electrical connector kit according to the present invention. A further advantage of this construction can be seen in the fact that less separate parts have to be stockpiled and handled at the facility where the sensors are assembled.

In order to securely fix the first or second peripheral connector at the interface element and/or the circuit carrier, locking means can be provided at the peripheral connectors. The locking means can for instance comprise a snap-fit connection. According to the present invention, this snap-fit connection does not necessarily have to be detachable because once the sensor is assembled, same usually needs not be disassembled again. Advantageously, the snap-fit connection is established between a snap-fit hook arranged at the peripheral connector and a mating recess provided at the housing of the sensor. The interface element can be attached to the circuit carrier in various different ways. A particularly space saving arrangement can be achieved by forming the interface element as a surface mount device (SMD) component which is connected to the circuit carrier for instance by means of reflow soldering. Moreover, the soldered connection provides a particularly robust and low ohmic electrical contact. Alternatively, the interface element may also be attached to the printed circuit board by means of the press-fit connection. Furthermore, when pre-assembling the interface element with each of the first and second peripheral connectors, a particularly simple and reliable way of connecting the interface element to the circuit carrier is to provide electrically conductive spring contacts for being connected to contacts arranged at an edge of the circuit carrier by means of a force fit. By providing respective guiding means, a correct mating of the interface element and the circuit carrier can be ensured.

According to the present invention, sealing means can be provided at the peripheral connectors so that a housing of the electronic circuitry is closed in a watertight and dustproof way after the peripheral connector is assembled. Consequently, no overmolding ("potting") is mandatory anymore. However, for certain applications it can still be useful to fill the housing with a casting resin. In this case and when using spring contacts, casting resin might enter between the spring contact and the circuit carrier, thereby deteriorating the electrical contact. It could be shown that this effect can be avoided by providing a protective cover at the interface element that protects the inner contacts against the intrusion of potting material.

The advantages of the present invention may best be used for an electronic component having a housing with an essentially cylindrical shell that at least partly encompasses the circuit carrier. The first and second peripheral connectors can be formed as a cover to close the shell, so that the electronic circuitry is effectively protected against the ingress of moisture and dust. Moreover, the cylindrical shell may at least partly be formed from an electrically conductive material, for instance metal, so that it provides a shielding of the sensor electronics against interfering signals.

The cylindrical shell may further comprise an additional electrically insulating end cap for receiving the first or second peripheral connector. Such an end cap could contain sensor specific display and input means, for instance light emitting diodes, potentiometers, and/or push buttons.

A method for assembling an electronic component according to the present invention comprises the step of attaching an interface element to a circuit carrier, so that at least one inner contact is contacting at least one electrically conductive lead on said circuit carrier, said interface element further comprising an electrically connecting interface for contacting a peripheral connector. The method further comprises the step of connecting either the first or the second peripheral connector to said connecting interface, wherein the first and second peripheral connectors have peripheral contact elements for contacting an external electronic component which differ from each other. In particular, either a plug connector or an electrical lead can thus be attached to the electronic component at an instant towards the end of the assembly process.

The sequence of these two steps according to the present invention depends on the particular embodiment of the interface element. In particular, for an interface element that is formed as an SMD component or is equipped with press-fit pins, the interface element has to be mounted at the circuit carrier before attaching the peripheral connector. On the other hand, for the embodiment of a clamping spring contact at the interface element it is advantageous to provide such an interface element at each peripheral connector before mounting same at the circuit carrier.

In any case, the choice what sort of peripheral connector is to be mounted at the sensor component can be postponed until the very last assembly steps.

In the foregoing, reference was always made to using the electrical connector kit with sensors and in particular with inductive proximity sensors. However, it is apparent for a person skilled in the art that the idea according to the present invention may also be used for any other kind of sensors or generally to other electronic components comprising circuit carriers having the need of peripheral contact elements for connecting the electronic component to external electronic components.

The accompanying drawings are incorporated into and form a part of the specification to illustrate several embodiments of the present invention. These drawings together with the description serve to explain the principles of the invention. The drawings are merely for the purpose of illustrating the preferred and alternative examples of how the invention can be made and used, and are not to be construed as limiting the invention to only the illustrated and described embodiments. Furthermore, several aspects of the embodiments may form— individually or in different combinations— solutions according to the present invention. Further features and advantages will become apparent from the following more particular description of the various embodiments of the invention, as illustrated in the accompanying drawings, in which like references refer to like elements, and wherein:

FIG. 1 shows schematically a sectional view of an inductive proximity sensor with a peripheral plug connector according to the present invention;

FIG. 2 shows schematically a sectional view of an inductive proximity sensor with a peripheral pigtail lead according to the present invention;

FIG. 3 shows a first assembly step for assembling the arrangement according to Figures 1 and 2;

FIG. 4 shows a further assembly step for assembling the arrangement according to Figures 1 and 2; FIG. 5 shows a further assembly step for assembling the arrangement according to Figures 1 and 2; FIG. 6 shows a further assembly step for assembling the arrangement according to Figures 1 and 2;

FIG. 7 shows a perspective view of a peripheral plug connector and an interface element according to the present invention;

FIG. 8 shows the arrangement of Fig. 7 rotated by 90°;

FIG. 9 shows schematically the position of the circuit carrier for the arrangement of Fig. 7;

FIG. 10 shows the arrangement of Fig. 9 rotated by 180°;

FIG 11 shows the arrangement of Fig. 7 without the protective cover;

FIG. 12 shows the arrangement of Fig. 1 1 in a rotated position;

FIG. 13 shows a perspective exploded view of the peripheral plug connector and interface element according to Fig. 7;

FIG. 14 shows a perspective view of a peripheral pigtail connector and an interface element according to the present invention;

FIG. 15 shows the arrangement of Fig. 14 in a rotated position;

FIG. 16 shows the arrangement of Fig. 16 in an exploded view;

FIG. 17 shows a further partly exploded view of the arrangement of Fig. 14;

FIG. 18 shows a perspective view of a peripheral cable connector and an interface element according to the present invention;

FIG. 19 shows the arrangement of Fig. 18 rotated by 180°;

FIG. 20 shows the arrangement of Fig. 18 in an exploded view;

FIG. 21 shows a perspective view of a peripheral cable connector with an interface element according to a further embodiment;

FIG. 22 shows the arrangement of Fig. 21 rotated by 90°;

FIG. 23 shows the arrangement of Fig. 21 in another rotated view; FIG. 24 shows a perspective view of a peripheral plug connector according to a further embodiment;

FIG. 25 shows an interface element to be connected with the peripheral plug connected according to Fig. 24; FIG. 26 shows the interface element of Fig. 25 and the belonging peripheral plug connector of

Fig. 25 before being connected;

FIG. 27 shows the arrangement of Fig. 21 in an exploded view;

FIG. 28 shows an embodiment of a peripheral plug connector using the interface element according to Fig. 25; FIG. 29 shows the arrangement of Fig. 28 rotated by 90°;

FIG. 30 shows the arrangement of Fig. 28 in an exploded view;

FIG. 31 shows an assembly step for fabricating the interface element of Fig. 25;

FIG. 32 shows a final step for fabricating the interface element of Fig. 25.

The present invention will now be explained in more detail with reference to the Figures. Referring now to Fig. 1 , an electronic component 100, in particular a sensor, is shown which is assembled using an electrically connector kit according to the present invention. The sensor 100 comprises a circuit board 102 which is for instance a printed circuit board (PCB) as known to a person skilled in the art. The circuit board 102 carries electronic components (not shown in this Figure) and transducer elements, such as a sensor coil in case the sensor 100 is an inductive proximity switch. A housing 104 encompasses the circuit board 102 and the components assembled thereon.

According to the present invention, an interface element 106 is mounted on the circuit carrier 102. The interface element 106 is electrically connected to the circuit carrier 102 by means of at least one inner contact 108. In the present case, a plurality of inner contacts 108 are provided at the interface element 106, each of them being connected to a connecting interface 1 10.

The connecting interface 1 10 is formed to be connected either with a peripheral plug connector 1 12 as shown in Fig. 1 or to a peripheral lead connector 1 14 as shown in Fig. 2. Of course, any other suitable alternative of how the peripheral connector can be formed is also covered by the present invention. For instance, the peripheral plug connector 1 12 can be formed to comply to the M12 5-position male connector according to the standard "Connectors for electronic equipment - Product requirements - Part 2-101 : Circular connectors - Detail specification for M12 connectors with screw-locking" (IEC 61076-2-101 :2012). A respective thread 1 16 for mechanically fixing the belonging mating connector is provided at the outside of a plastic cap 1 18.

Locking means 120 are provided for mechanically fixing the peripheral connector 1 12 at the interface element 106 and therefore also at the PCB 102. As schematically shown in Fig. 1 , the locking means 120 comprise a ring-shaped or hook-shaped snap-in connector. According to the present invention, this snap-fit connection does not have to be releasable after the peripheral connector has been assembled.

The connecting interface 1 10 between the interface element 106 and the peripheral connector 1 12 or 1 14 is advantageously formed by a press-fit connection. The electrical connection between the interface element 106 and conductive tracks on the PCB 102 may for instance be established by means of reflow soldering. In particular, the interface element 106 can be formed as an SMD (surface mount device) component. However, it is clear for a person skilled in the art that also other suitable ways of contacting the PCB 102 can be employed at this point.

According to the embodiment shown in Figures 1 to 6, the PCB 102 is mounted within an M12, M18, or M30 metal housing 104. Such a metal housing has the advantage that the electronic circuitry inside the housing 104 is protected against disturbing signals from the outside. Forming the housing 104 from two separate parts, namely an elongated metal shell 122 and a separate plastic cap 1 18, has the advantage that more complicated geometries for display and control elements can easily be combined with a shielding structure. The plastic cap 1 18 may for instance be formed as an injection molded part.

Fig. 2 shows the same electronic component 100 which in contrast to the arrangement of Fig. 1 is not equipped with a peripheral plug connector 1 12, but with the peripheral lead connector 1 14. This different peripheral connector 1 14 carries a cable 124, and the sensor 100 therefore forms a so-called pigtail. It has to be noted that the other end of the cable 124 may carry any suitable connector for contacting an external device (not shown in the Figures). The cable 124 may be a flat flexible cable, a coaxial cable, or any other electrical lead as required for contacting the external device.

Figures 3 to 6 illustrate an exemplary embodiment of an assembly method using an electrical connector kit according to the present invention. As shown in Fig. 3, according to a first embodiment of the present invention, the circuit carrier 102 is equipped with an interface element 106. The inner contacts 108 are connected to electrical leads on the circuit carrier 102 for instance by means of reflow soldering. As shown in Fig. 4, the printed circuit board 102 with the assembled interface element 106 is inserted into an essentially cylindrical metal shell 122 in a direction 126 along a longitudinal axis of the electronic component. The metal shell 122 has suitable guiding means (not shown in the Figures) for guiding and holding the PCB 102. In a next step (see Fig. 5) a plastic cap 1 18 is inserted along the same direction 126 corresponding to the longitudinal axis of the electronic component. As will become more apparent from the following Figures, the plastic end cap 1 18 comprises a circumferential shoulder 128 for interacting with the locking means 120 of the peripheral connectors 1 12, 1 14.

Fig. 6 shows the point in the assembly procedure when it is determined whether the electronic component 100 is equipped with the peripheral plug connector 1 12 or with the peripheral lead connector 1 14. According to the present invention, the electrical connector kit comprises in addition to the interface element 106 also a set of at least one first and second peripheral connector 1 12, 1 14 which selectively can be connected to the interface element 106. As shown in the drawing, either a plug connector 1 12 or a lead connector 1 14 having a cable 124 can be attached to the interface element 106.

The respective peripheral connector 1 12, 1 14 is inserted along the longitudinal axis of the electronic component 100. A circumferential snap-fit element is provided as locking means 120 and engages with the shoulder 128 at the end cap 1 18 in an essentially irreversible manner. In addition to the peripheral connectors 1 12, 1 14 shown in Fig. 6, of course also other peripheral connectors can be part of the electrical connector kit. For instance, means for a wireless connection, a plug connector socket, or another type of pin connector can be provided.

In the embodiment shown in Fig. 6, the peripheral connectors 1 12, 1 14 are equipped with press-fit contacts 130 that connect the respective peripheral connector 1 12, 1 14 to the connecting interface 1 10 of the interface element 106. However, also abutting spring contacts can be used instead of the press-fit contacts 130.

The connection between the respective peripheral connector 1 12, 1 14 and the plastic end cap 1 18 can be designed in a way that the housing 104 is closed in a watertight and dustproof way. Alternatively, an additional casting step may also be performed for sealing the arrangement.

A further advantageous embodiment of the present invention will be described with reference to Figures 7 to 20. This embodiment mainly differs from the previous embodiment in that an interface element 106 is first connected to each of the peripheral connectors 1 12, 1 14, and that the connection between the interface element 106 and the circuit carrier 102 is established in the same step when assembling the peripheral connectors 1 12, 1 14. This embodiment has the advantage that firstly the amount of lose parts belonging to the electrical connector kit is reduced and that secondly the proprietary components belonging to the harnessing and peripheral contacts are introduced into the process of fabricating an electronic sensor component even later in the process sequence. Figures 7 to 10 show a peripheral plug connector 1 12 with an attached interface element 106. According to this particular embodiment, the interface element 106 is formed to engage with a PCB 102 in a clamping manner. To this end, the interface element 106 comprises spring contacts 132 which engage with contact areas (not shown in the Figures) provided on the printed circuit board 102. A snap-fit projection 134 is formed at the outside of the peripheral plug connector 1 12 for engaging with a belonging recess or shoulder provided at the sensor housing. Moreover, a ring- shaped gasket 136 seals the mechanical interface between the housing and the inserted peripheral plug connector 1 12 in the final mounted state.

The spring contacts 132 are pushed over the printed circuit board 102 and establish an electrical contact due to the spring forces of the contact 132. These forces mainly are oriented across to the insertion direction 126. However, when overmolding the circuit carrier 102 by filling a cast resin into the housing (not shown in the Figures), electrically insulating material can enter between the spring contacts 132 and the printed circuit board 102, thereby deteriorating the quality of the electrical contact. Consequently, the interface element 106 comprises a cover 138 for protecting the spring contacts 132 against the ingress of the cast resin. Preferably, the cover 138 is fabricated from an elastic material, so that it is in tight contact with the PCB 102 before the cast resin is filled in.

Figures 1 1 and 12 show the contact area of the interface element 106 without the cover 138.

Fig. 13 shows an exploded view of the components forming the arrangement of Fig. 7. In particular, the interface element 106 comprises spring contacts 132 which are assembled in the contact carrier 140. In order to form a connecting interface 1 10 towards the peripheral plug connector 1 12, the spring contacts 132 are connected to an intermediate circuit board 142. The intermediate circuit board 142 has metallized contact openings 144 (vias) for receiving the spring contacts 132. Moreover, the intermediate circuit board 142 is provided with a second plurality of metallized openings 146 (vias) which receive the plug connector pins 148 of the peripheral plug connector 1 12. Conducting paths (not shown in the Figures) are provided in the intermediate circuit board 142 that interconnect the vias 144, 146 and thereby electrically connect the spring contacts 132 with the belonging connector pins 148. As already mentioned, the gasket 136 (which is to be arranged in a groove 150) seals the interface between the housing and the interface element 106.

Fig. 14 to 17 show the belonging peripheral lead connector that belongs to the same connector kit as the plug connector 1 12 shown in Figures 7 to 13. As can be seen in Figures 14 and 15, the interface towards the PCB 102 is identical and shows spring contacts 132 that contact the PCB 102 by clamping it from two sides at the edge. An elastic protective cover 138 is provided for preventing that casting resin is drawn by capillary forces into the minute gap between the PCB 102 and the spring contacts 132.

In contrast to the peripheral plug connector 1 12 shown in Figures 7 to 13, the peripheral lead connector 1 14 comprises a plurality of electrically insulated wires 152 with a conductive core. The wires 152 may either be attached to the peripheral lead connector 1 14 as single leads or may form a ribbon cable. Although an arrangement with an intermediate circuit board 142 as shown in Figures 13 may also be used for fabricating the peripheral lead connector 1 14 of Figures 14 and 15, it is even more efficient to directly connect the wires 152 to the spring contacts 132. This embodiment is illustrated in Figures 16 and 17. In particular, the spring contacts 132 have insulation displacement terminations 154 for cutting the insulation of the wires 152 and electrically connecting the conductive cores of the wires 152.

A further peripheral lead connector 1 14 with an attached interface element 106 is depicted in Figures 18 to 20. According to this embodiment, the outgoing cable 124 is protected by a tension relief 156. Furthermore, the tension relief 156 is formed of an elastic material and comprises a sealing rim 158 which can replace the gasket 136.

Fig. 20 illustrates a further possibility of attaching the wires of the cable 124 to the spring contacts 132. According to this embodiment, the spring contacts have crimp regions 164 for attaching the individual wires of the cable. For fabricating the arrangement shown in Fig. 18, the ends of the wires (not shown in Fig. 20) are first stripped from their insulation and then crimped individually to one spring contact 132 each. The spring contacts 132 are then arranged in holder 162 and inserted into the contact carrier 140. Next, the protective cover 138 and the tension release 156 are attached. This arrangement provides a combined peripheral plug connector 1 12 with an interface element 106. Figures 21 to 32 illustrate a further advantageous embodiment of a connector kit according to the present invention. Figures 21 to 27 relate to the peripheral lead connector 1 14 whereas Figures 28 to 30 show the corresponding peripheral plug connector 1 12. Figures 31 and 32 illustrate the assembly of the interface element 106. As shown in Fig. 21 , the wires 152 are attached by means of crimp connections 164 to the peripheral lead connector 1 14. The interface element 106 comprises inner contacts 108 that are soldered to the respective contact pads 166 provided at the PCB 102. As becomes more apparent from Fig. 25, the interface element 106 comprises an electrically insulating body 168 and a plurality of inner contacts 108 that provide a connecting interface 1 10 for the peripheral plug connector 1 12. An electrically insulating housing 170 of the peripheral plug connector has receptacles 172 through which EON (eye-of-the-needle) contacts 174 can be inserted. Fig. 26 shows the arrangement before being plugged together.

Fig. 27 illustrates in an exploded view how the interface element 106 contacts the peripheral lead connector 1 14 with its EON contacts 174. Similar to the embodiment shown in Fig. 13, an intermediate circuit board 142 is provided within the housing 170 of the peripheral connector.

Wires 152 are fixed by crimp connections 164 to further EON contacts 176. After the interface element 106 is soldered to the PCB 102, same is mounted within a housing (as shown in Fig.

5). The peripheral lead connector 1 14 is assembled by attaching the wires 152 at the intermediate circuit board 142 contained within the housing 170. Finally, the peripheral lead connector 1 14 is connected to the EON contacts 174 by inserting the lead connector 1 14 partly into the housing 104.

Figures 28 to 30 depict the corresponding peripheral plug connector 1 12. The construction of the plug connector 1 12 is similar to the design of the lead connector 1 14, with the exception that the housing is formed to hold plug connector pins 148 which are connected to an intermediate circuit board 142 by EON contacts 178. The connector housing 180 of the peripheral connector 1 12 has identical receptacles 172 for receiving the contacts 174 of the interface element 106. A suitable wiring provided within the intermediate circuit board 142 provides the connection between the inner contacts 108 and the pins 148. Fig. 31 and 32, finally, illustrate the fabrication of the interface element 106 with solderable inner contacts 108 and eye-of-the-needle contacts 174 at the connecting interface 1 10.

Firstly, the EON contacts 174 are fabricated as one single part with the inner contacts 108. These contacts are then arranged in an electrically insulating body 182. A cover 182 is mounted on the body 168 in order to fix the contact at the body and an ultrasonic welding step (illustrated by the arrow 184) connects the cover 182 to the body 168.

An electrical connector kit for a circuit carrier 102 according to the present invention comprises at least one interface element 106 and at least one of the peripheral plug connector 1 12 and the peripheral lead connector 1 14. Consequently, when assembling an electronic component such as an inductive proximity switch, the decision whether a lead connector or a plug connector has to be mounted can be made towards the end of the assembly process. Is clear for a person skilled in the art that further peripheral connectors may of course also be provided with the electrical connector kit.

The use of the terms "a" and "an" and "the" and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "comprising", "having", "including", and "containing" are to be construed as open-ended terms (i. e., meaning "including, but not limited to") unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. "such as") provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

Exemplary embodiments are described herein. Variations of those embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor(s) expect skilled artisans to employ such variations as appropriate, and the inventor(s) intend for the invention to be practiced otherwise than as specifically described herein. In particular, the Figures only show an inductive sensor as the electronic component according to the present invention. However, the ideas according to the present invention are of course applicable to any other conf iguration where a circuit carrier is to be equipped with either a peripheral plug connector or a peripheral output lead at a point late in the assembly process.

Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context. REFERENCE NUMERALS

Reference Numeral Description

100 Electronic component

102 Circuit carrier (PCB)

104 Housing

106 Interface element

108 Inner contact

1 10 Connecting interface

1 12 Peripheral plug connector

1 14 Peripheral lead connector

1 16 Thread

1 18 Plastic end cap

120 Locking means

122 Metal shell

124 Cable

126 Inserting direction

128 Shoulder at end cap

130 Press-fit contact

132 Spring contact

134 Snap-fit projection

136 Ring-shaped gasket

138 Protective cover

140 Contact carrier

142 Intermediate circuit board

144 First metallized opening

146 Second metallized opening

148 Plug connector pins

150 Groove

152 Wire

154 Insulation displacement termination

156 Tension relief

158 Ceiling rim

160 Crimp region

162 Holder

164 Crimp connection 166 Contact pad

168 Body of interface element

170 Housing of peripheral lead connector

172 Receptacle

174 EON contact of interface element

176 EON contact of peripheral connector

178 EON contact of pin

180 Housing of peripheral plug connector

182 Cover of interface element

Claims

Electrical connector kit for a circuit carrier (102) comprising: at least one interface element (106) which is attachable to said circuit carrier (102) and which has at least one inner contact (108) for contacting at least one electrically conductive lead on said circuit carrier (102), said interface element (106) further comprising an electrically connecting interface (1 10) for contacting a peripheral connector (1 12, 1 14); a set of at least one first and second peripheral connectors (1 12, 1 14), each being connectable to said connecting interface (1 10), wherein, for contacting at least one external electronic component, said first and second peripheral connectors (1 12, 1 14) have peripheral contact elements (148, 152, 124) which differ from each other.

Electrical connector kit according to claim 1 , wherein the peripheral contact element of the first peripheral connector (1 12) comprises a plug connector, and wherein the peripheral contact element of the second peripheral connector (1 14) comprises an electrical lead (152, 124) attached thereto.

Electrical connector kit according to claim 1 or 2, wherein the kit comprises said interface element (106) as a part separate from the first and second peripheral connectors (1 12, 1 14).

Electrical connector kit according to claim 1 or 2, wherein one interface element (106) is provided for each of said first and second peripheral connectors (1 12, 1 14).

Electrical connector kit according to claim 1 or 2, wherein said first and second peripheral connectors (1 12, 1 14) comprise locking means (120) for mechanically securing the peripheral connectors at the interface element (106) in a mounted state.

Electrical connector kit according to one of the preceding claims, wherein the interface element (106) and the peripheral connectors (1 12, 1 14) are connectable to each other by means of a press-fit connection.

Electrical connector kit according to one of the preceding claims, wherein said interface element (106) is formed as a surface mount device, SMD, component which can be attached to said circuit carrier (102) by means of reflow soldering, or wherein said interface element (106) comprises electrically conductive spring contacts (132) for being connected to contacts arranged at an edge of said circuit carrier (102) by means of a force fit.

8. Electrical connector kit according to claim 7, wherein said interface element (106) comprises a protective cover (138) for protecting said inner contacts against intrusion of potting material during the assembly process.

9. Electronic component comprising at least one circuit carrier (102), and an electrical connector kit according to one of the preceding claims.

10. Electronic component according to claim 9, wherein said circuit carrier (102) comprises at least one inductive proximity sensor.

1 1 . Electronic component according to one of the claims 9 or 10, further comprising a housing (104) that at least partly encompasses said circuit carrier (102), wherein each of said peripheral connectors (1 12, 1 14) has locking means (120) that interact with said housing (104) for mechanically securing the peripheral connector at the interface element.

12. Electronic component according to claim 1 1 , wherein said housing (104) comprises an essentially cylindrical shell (122, 1 18), and wherein said first and second peripheral connectors (1 12, 1 14) are formed as a cover to close said shell (122, 1 18).

13. Electronic component according to claim 12, wherein said cylindrical shell comprises an electrically conductive shielding part (122) and an electrically insulating end cap (1 18) for receiving said first or second peripheral connector (1 12, 1 14).

14. Method for assembling an electronic component comprising the following steps: attaching an interface element (106) to a circuit carrier (102), so that at least one inner contact (108) is contacting at least one electrically conductive lead on said circuit carrier (102), said interface element (106) further comprising an electrically connecting interface (1 10) for contacting a peripheral connector (1 12, 1 14); connecting either a first or a second peripheral connector (1 12, 1 14) to said connecting interface (1 10), wherein said first and second peripheral connectors (1 12, 1 14) have peripheral contact elements (148, 152, 124) for contacting an external electronic component which differ from each other.

15. Method according to claim 14, wherein said interface element (106) is attached as a separate element to the circuit carrier (102) before mounting either the first or second peripheral connector (1 12, 1 14), or wherein one interface element (106) is attached to each of the first and second peripheral connectors (1 12, 1 14) before being mounted at the circuit carrier (102).