EP2878041B1 - Contact element - Google Patents

Description

The invention relates to a contact element with an outer conductor and an inner conductor disposed within the outer conductor, which are each provided on the front side for contacting a component and in particular a printed circuit board.

Such contact elements can serve, for example, to connect cable-shaped (coaxial) conductors to the corresponding contact points of a printed circuit board. Likewise, such contact elements may be provided for the electrically conductive connection of two printed circuit boards.

If such contact elements serve as part of a transmission path for high-frequency signals, special demands are placed on the contact of the outer and inner conductors with the contact points of the printed circuit board.

The inner conductor is then regularly called spring contact pin, also called "Pogopin" formed. Such a spring contact pin comprises a sleeve and a bolt partially guided within the sleeve with a contact head. A coiled between the bolt and the sleeve coil spring causes a spring load of the bolt in its extended position. The spring load causes the contact head of the bolt always has a secure contact with sufficient contact pressure with the contact point even when tolerated due to different distances of the spring contact pin to the contact point on the circuit board. The contact head is regularly hemispherical in shape, whereby tolerance-related deviations from the vertical orientation of the spring contact pin are compensated for the contact point, ie the contact surface of the contact head is always substantially the same size.

The outer conductor which regularly concentrically surrounds the inner conductor has an annular end face, which in many cases also serves as a contact surface. This is disadvantageous in particular in the case of a tolerance-dependent not exactly perpendicular alignment of the outer conductor to the contact surface of the printed circuit board. Then, a lateral lifting of the contact surface leads to a contact with the contact point in only a comparatively small portion of the end face of the outer conductor. Such "uncontrolled" contact is particularly undesirable when using the contact elements for the transmission of high-frequency signals.

The publication US 2002/0050388 A1 describes a contact element for attaching one or more coaxial cables directly to a printed circuit board substrate. The contact point may be resilient.

Based on this prior art, the present invention seeks to provide an improved generic contact element. In particular, a generic contact element with respect to the contact between the outer conductor and the associated contact point on the circuit board should be improved.

This object is achieved by a contact element according to independent claim 1. Advantageous embodiments are the subject of the dependent claims and will become apparent from the following description of the invention.

The invention solves this problem by providing in a generic contact element with an outer conductor and a (preferably coaxially) disposed inside the outer conductor inner conductor, wherein the outer conductor at (at least) one of its longitudinal axial end faces (at least) a contact point for contact with a contact point a component to be contacted and in particular a printed circuit board, the contact point is resiliently mounted.

In this case, the end face of the outer conductor is formed by a formed as a corrugated ring contact ring, which is connected to a housing of the outer conductor. This simplifies the integration of the resilient mounting of the contact point and thus the production of the contact element according to the invention.

A connection of the contact ring with the housing of the outer conductor is achieved in a simple manner that the contact ring is at least partially held edgewise between the housing and a lid. The cover may be connected to the housing in any desired manner, for example by a force fit (for example as a press fit), a form fit (for example by means of a bayonet or threaded connection) and / or a material fit (for example by soldering or welding).

It is provided that the contact ring is formed as (preferably disk-shaped) corrugated ring. Such a corrugated ring has a wave-shaped course in the circumferential direction, as a result of which at least one, preferably several corrugation-wave trough combinations are created. Then, for example, the wave crests may serve as contact points for contact with the contact point of the printed circuit board and the wave troughs as contact points, which ensure contact with the housing of the outer conductor. Preferably, the corrugated ring is made of a metallic material such as e.g. Copper formed. As a result, an electrically conductive contact ring can be created in a cost effective manner, which can also exploit the advantageous elastic properties of the material for the integration of the resilient mounting of the contact point.

In a further advantageous embodiment, the preferably a plurality of resiliently mounted contact points of the contact ring may be formed by one or more spring tabs, which preferably run inclined in the direction of a center axis of the contact ring. The spring tabs are preferably integrally connected to a main body of the contact ring, wherein preferably (at least) one contact point at the free end (preferably each) of the spring tabs is provided.

In one embodiment it can be provided that the spring tabs are designed to extend radially inwardly. It is also possible to form the spring tab arcuately running around the central axis of the contact ring.

In a non-claimed example of a contact element can be provided that the contact ring is partially formed of metal felt. When metal felt is a spatial structure of intertwined fibers, at least partially made of electrically conductive material consist. An elasticity of the contact ring then results from an elastic deformation of the fibers in conjunction with a relative mobility between them. The contact points of a metal felt contact ring may be formed by portions of the fibers.

Of course, there is the possibility that a contact ring of the contact element according to the invention comprises several or all of the spring contact contact points described as preferred. For example, a trained as a corrugated ring contact ring may be additionally formed with spring tabs. In a further embodiment, a corrugated ring, optionally with additional spring tabs, may be combined with an underlying second metal felt contact ring. A contact ring of the contact element according to the invention can thus also have a multilayer structure.

Fig. 1:

ein erfindungsgemäßes Kontaktelement in einer perspektivischen Ansicht;

Fig. 2:

das Kontaktelement der Fig. 1 in einer Explosionsdarstellung;

Fig. 3:

das Kontaktelement der Fig. 1 und 2 in einem Längsschnitt;

Fig. 4:

eine erste Ausführungsform eines Kontaktrings zur Verwendung mit dem Kontaktelement der Fig. 1 bis 3;

Fig. 5:

eine zweite Ausführungsform eines Kontaktrings zur Verwendung mit dem Kontaktelement der Fig. 1 bis 3;

Fig. 6:

eine dritte Ausführungsform eines Kontaktrings zur Verwendung mit einem Kontaktelement der Fig. 1 bis 3;

Fig. 7:

ein System aus einer Verbindungsvorrichtung für eine Vielzahl von Kontaktelementen der Fig. 1 bis 3 und einer Leiterplatte in einer Explosionsdarstellung.

Fig. 8:

das System der Fig. 7 in einer Aufsicht;

Fig. 9:

das System der Fig. 7 und 8 in einer Seitenansicht

Fig. 10:

die Leiterplatte des Systems der Fig. 7 bis 9 in einer Ansicht von unten; und

Fig. 11:

die Leiterplatte der Fig. 10 in einem Querschnitt.

The invention will be explained in more detail with reference to embodiments shown in the drawings. In the drawings shows:

Fig. 1:

an inventive contact element in a perspective view;

Fig. 2:

the contact element of Fig. 1 in an exploded view;

3:

the contact element of Fig. 1 and 2 in a longitudinal section;

4:

a first embodiment of a contact ring for use with the contact element of Fig. 1 to 3 ;

Fig. 5:

a second embodiment of a contact ring for use with the contact element of Fig. 1 to 3 ;

Fig. 6:

a third embodiment of a contact ring for use with a contact element of Fig. 1 to 3 ;

Fig. 7:

a system of a connecting device for a plurality of contact elements of Fig. 1 to 3 and a circuit board in an exploded view.

Fig. 8:

the system of Fig. 7 in a supervision;

Fig. 9:

the system of FIGS. 7 and 8 in a side view

Fig. 10:

the circuit board of the system Fig. 7 to 9 in a view from below; and

Fig. 11:

the circuit board of Fig. 10 in a cross section.

The Fig. 1 to 3 show an embodiment of a contact element 19 according to the invention. This serves a (coaxial) cable 1 with an associated contact point of a printed circuit board 2 (see. Fig. 7 to 11 ) connect to. In this case, 2 high-frequency signals are to be transmitted between the cable 1 and the circuit board.

The contact element 19 has an inner conductor 3 of electrically conductive material, in particular a metal (for example copper and / or steel), which is designed in the form of a spring contact pin. This comprises a sleeve 4 with a blind hole extending in the longitudinal axial direction. In this blind hole, a bolt 5 is movably mounted, wherein a contact head of the bolt 5 projects beyond the blind hole of the sleeve 4. The bolt 5 is mounted by means of a (screw) spring 6 resiliently in the sleeve 4, wherein a bias of the spring 6 acts on the bolt 5 in the direction of the open end of the blind hole. The contact head of the bolt 5 has a curved and in particular hemispherical contact surface which is provided for contact with the associated contact point of the printed circuit board 2.

The inner conductor 3 is held in inner bores of two insulating bodies 7 of electrically insulating material, in particular plastic. In this case, the sleeve 4 is supported with an arranged near its cable-side end annular shoulder 8 on the cable-side insulating body 7, while an annular projection 9 on the pin 5 in the vicinity of the contact head whose spring-loaded Moving out of the sleeve 4 limited by a stop on the cable side insulation body 7.

A connection of the inner conductor 3 of the contact element 19 with an inner conductor of the associated cable 1 via a plug connection. For this purpose, the rear end of the sleeve 4 in the form of a longitudinally or multi-slotted socket 10 is formed, in which a plug of the inner conductor of the cable 1 is inserted.

The inner conductor 3 receiving insulation body 7 are held in inner holes of an outer conductor. This results in a coaxial position of inner conductor 3 and outer conductor (based on the longitudinal axes). The multi-part outer conductor comprises a first, substantially cylindrically shaped housing part 11, which is screwed to a second, likewise substantially cylindrically shaped housing part 12. For this purpose, the first housing part 11 forms an external thread which is screwed to an internal thread of the second housing part 12.

In the cable-side end of the second housing part 12, a soldering bush 13 is inserted (made of an electrically conductive material) and fixed non-positively. The solder jack 13 and the second housing part 12 may consist of different materials. A plugged into the receiving opening of the solder jack 13 and thus electrically connected outer conductor of the cable 1 is soldered to fix the cable 1 with the solder jack 13.

The second housing part 12 is surrounded on the outside by a spring 14, the exact positioning of the contact element 19 in the in the Fig. 7 to 11 used and described in more detail later connecting device is used.

The front longitudinal axial end surface of the outer conductor, which is provided for contact with the contact point of the printed circuit board 2, is formed by a contact ring 28 in the form of a corrugated ring, which has a wave-shaped course along its circumference. In this case, a total of three wave crests and wave troughs are formed, wherein the wave troughs abuts against the end face of the first housing part 11 of the outer conductor, while the wave crests are provided as contact points for contacting the contact point of the printed circuit board 2. In the area of the wave troughs, the contact ring 28 In addition, in each case a radially outwardly facing tab 15. The tabs 15 are fixed in a gap, which is formed between the first housing part 11 and a non-positively connected thereto cover 16, positively. Preferably, the tabs 15 are not significantly clamped between the first housing part 11 and the cover 16, so that there is a rotatable attachment of the corrugated ring 14 on the housing of the outer conductor. Upon contact of the corrugated ring 14 with the contact point of the printed circuit board 2, the corrugated ring is deformed more or less, resulting in a spring load of formed in the form of wave crests contact points due to the elastic properties of the example formed of copper corrugated ring 14. The deformation of the contact points can be done individually, whereby a compensation of a non-uniform distance of the contact point of the circuit board of the corrugated ring 14, in particular caused by a not exactly vertical orientation of the longitudinal axis of the contact element 19 to the contact point of the circuit board 2, takes place. Despite this misalignment a permanent contact of all contact points of the corrugated ring 14 is secured with the associated contact point of the circuit board 2 by the spring load.

The 4 to 6 show alternative embodiments for contact rings 28, which instead of the corrugated ring 14 in the contact element 19 according to the Fig. 1 to 3 can be used.

In the contact rings 28 according to the Fig. 4 and 5 the contact points of spring tabs 17 are formed, which are integrally formed with a flat, annular body 18 of the contact ring 28. In this case, the contact tabs 17, which in the embodiment according to the Fig. 4 pointing radially inward and in the embodiment according to the Fig. 5 arcuately arranged around a central axis of the contact ring 28, arranged slightly inclined in the direction of the central axis. As a result, the contact points formed by the spring tabs 17 (in the direction of the longitudinal axis of the contact element 19) have a defined distance from the base body 18. These can thus avoid spring-loaded in contact with the contact point of the printed circuit board 2 in the direction of the cable-side end of the contact element 19. This allows a compensation of a non-uniform distance of the contact point of the printed circuit board 2 from the main body 18 of the contact ring 28, in particular highlighted by a not exactly parallel alignment with each other. Despite this misalignment is due to the spring load permanent contact of all contact points of the contact element 19 secured with the associated contact point of the circuit board 2.

In the embodiment according to the Fig. 6 the contact ring 28 is formed of metal felt, that is, this consists of a plurality of metallic fibers (wires), which are intertwined into each other. Several of the fibers form one or more contact points, which can yield elastically due to an elastic deformation of the individual fibers and a relative movement of the fibers in contact with the contact point of the printed circuit board 2. This embodiment of a contact ring 28 also allows permanent contact and thus reliable transmission of the high-frequency signals between the cable 1 and the printed circuit board 2.

The Fig. 7 to 11 show a connecting device by means of a plurality of contact elements 19, as for example in the Fig. 1 to 3 are shown, can be connected to the circuit board 2.

The connecting device comprises a housing with a lower housing part 20 and an upper housing part 21. The lower housing part 20 has a number of contact elements 19 corresponding number of passage openings, in each of which a contact element 19 is inserted. In the area of that outer surface of the lower housing part 20, which is directly adjacent to the printed circuit board 2 (contact side), an annular, the diameter of the passage openings decreasing paragraph is provided within the through holes in each case. At these paragraphs, the recorded in the through holes contact elements 19 are based contact side. In this case, the diameter of the passage openings formed by the shoulders is so large that the contact points formed on the outer conductor of the contact elements 19 protrude and thereby project beyond the lower housing part.

The upper housing part 21 surrounds the cable-side ends of the contact elements 19. Within the upper housing part 21, a counter-holder 22 is arranged, which has substantially the same outer dimensions as the lower housing part 20 and also a plurality of through-openings, in each of which the cable end of the Outer conductor of one of the contact elements 19 is inserted.

The diameter of the through holes is only slightly larger than the outer diameter of the cable-side ends of the contact elements 19, whereby the cable-side ends of the plugged onto the second housing parts 12 of the outer conductor of the contact elements 19 springs 14 are supported on the anvil 22. In conjunction with the front-side support of the springs 19 on an annular shoulder of the second housing part 12 of the outer conductor of the contact parts 19 can thereby be achieved in the mounted state of the connecting device, a spring bias, pressed by the contact elements 19 against the heels in the through holes of the lower housing part 21 become. As a result, in particular good contact of the contact points of the outer conductor of the contact parts 19 with the associated contact points of the printed circuit board 2 is to be ensured.

A connection between the lower housing part 20, the anvil 22 and the upper housing part 21 can be made in any way. Preferred is a releasable connection, which may be formed for example by a latching connection.

On the longitudinal sides of the lower housing part 20 are each two locking tabs 23 made of an elastic, preferably metallic material (for example steel) attached. Each of the locking tabs 24 forms at least one projection which engages behind the edge of the associated passage opening 24 of the printed circuit board 2, whereby a latching connection between the connecting device and the circuit board 2 is produced.

As in particular from the Fig. 11 can be seen, the through holes 24 of the circuit board 2 are formed stepped. Each of the steps (shown are two, more than two can be advantageously provided) forms an edge, behind which the projection of the associated latching tab 23 of the connecting device can engage. The differing by their distance from the contact-side surface of the circuit board 2 stages of the through holes 24 allow a simple and secure connection of the connecting device to the circuit board 2 even with comparatively large tolerance dimensional deviations, in particular the components of the connecting device.

The lower housing part 20 of the connecting device still has two additional through openings, which are arranged next to the passage openings for the contact elements 19 and - like these - have on the contact side of the lower housing part 20 an annular shoulder for diameter reduction. These two through holes each receive a threaded sleeve 25, which is preferably formed of metal. In each case, the external thread of a fastening screw 26 can be screwed into these threaded sleeves 25 (with internal thread). The fastening screws 26 then protrude through additional passage openings 27 of the printed circuit board 2 and are supported on the side of the printed circuit board 2 opposite the contact side. As a result, the connecting device can optionally be screwed to the printed circuit board 2, in particular in the case of special requirements for a permanently secure fastening. The screw heads of the fastening screws are provided with a relatively large diameter and - optionally - with a ribbing on the edge, which makes a manual tightening and loosening of the screw possible.

The dimensioning of the elements of the connecting device and the printed circuit board 2 and the interpretation of the spring stiffness of the springs 6, 14 and the spring-acting contact rings 28 of the contact elements 19 are preferably selected so that the contact side of the lower housing part 20 of the connecting device not directly on the adjacent surface of the Printed circuit board 2 is applied; rather, a small gap should remain. Otherwise, a concern of the lower housing part 20 on the printed circuit board 2 could hinder a defined spring-loaded contact of the inner and / or outer conductor (or the contact points formed by the contact rings 28) or all of the contact elements 19.

Claims (5)

1. Contact element (19) with an outer conductor and an inner conductor (3) arranged within the outer conductor, wherein the outer conductor has on one of its longitudinal axial end surfaces at least one contact point for making contact with a contact point of a component which is to be contacted, wherein the contact point is spring-mounted, characterised in that the end surface is formed by a contact ring (28) in the form of a corrugated ring which is connected with a housing of the outer conductor and held at the edges between the housing and a cover (16).
2. Contact element (19) according to claim 1, characterised in that the contact ring (28) has spring tabs (17) .
3. Contact element (19) according to claim 2, characterised in that the spring tabs (17) are configured to extend radially inwards.
4. Contact element (19) according to claim 2, characterised in that the spring tabs (17) are arranged in an arc around the central axis of the contact ring (28).
5. Contact element (19) according to one of the preceding claims, characterised in that the contact ring (28) is combined with an underlying second contact ring made of metal felt.

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